feat: added bot, light and dark mode

angular.json

@@ -53,6 +53,12 @@
               "outputHashing": "all"
             },
             "development": {
+              "fileReplacements": [
+                {
+                  "replace": "src/environments/environment.ts",
+                  "with": "src/environments/environment.development.ts"
+                }
+              ],
               "optimization": false,
               "extractLicenses": false,
               "sourceMap": true
@@ -62,6 +68,9 @@
         },
         "serve": {
           "builder": "@angular/build:dev-server",
+          "options": {
+            "proxyConfig": "proxy.conf.json"
+          },
           "configurations": {
             "production": {
               "buildTarget": "nowchess-frontend:build:production"

docs/board-api-spec.yaml

@@ -1,6 +1,6 @@
 openapi: 3.0.3
 info:
-  title: NowChess API
+  title: NowChess Board API
   description: |
     REST API for the NowChess application. Designed to feel familiar to users
     of the [lichess API](https://lichess.org/api).
@@ -186,11 +186,8 @@ paths:
         currently to move.
 
         For promotion moves include the target piece as the fifth character:
-        `e7e8q`, `a2a1r`, etc.
+        `e7e8q`, `a2a1r`, etc. Promotion moves without the fifth character
-
+        are rejected with `400 INVALID_MOVE`.
-        If the move results in a pawn reaching the back rank and no promotion
-        character is supplied, the game enters `promotionPending` status and
-        the move is not yet applied — resubmit with the promotion character.
       security:
         - bearerAuth: []
       parameters:
@@ -630,7 +627,6 @@ components:
         | `draw` | Draw agreed or claimed — game over |
         | `drawOffered` | Waiting for the opponent to accept or decline a draw offer |
         | `fiftyMoveAvailable` | Fifty-move rule threshold reached; active player may claim draw |
-        | `promotionPending` | A pawn reached the back rank; awaiting promotion piece selection |
         | `insufficientMaterial` | Neither side has enough pieces to deliver checkmate — game over (draw) |
       enum:
         - started
@@ -641,7 +637,6 @@ components:
         - draw
         - drawOffered
         - fiftyMoveAvailable
-        - promotionPending
         - insufficientMaterial
 
     # -------------------------------------------------------------------------

proxy.conf.json

@@ -0,0 +1,8 @@
+{
+  "/api": {
+    "target": "http://localhost:8080",
+    "secure": false,
+    "changeOrigin": true,
+    "ws": true
+  }
+}

src/app/app.ts

@@ -1,4 +1,4 @@
-import { Component } from '@angular/core';
+import { Component, OnInit } from '@angular/core';
 import { RouterOutlet } from '@angular/router';
 
 @Component({
@@ -7,5 +7,15 @@ import { RouterOutlet } from '@angular/router';
   templateUrl: './app.html',
   styleUrl: './app.css'
 })
-export class App {
+export class App implements OnInit {
+  ngOnInit(): void {
+    this.initTheme();
+  }
+
+  private initTheme(): void {
+    const savedTheme = localStorage.getItem('theme');
+    if (savedTheme === 'dark') {
+      document.documentElement.setAttribute('data-theme', 'dark');
+    }
+  }
 }

src/app/components/chess-board/chess-board.component.css

@@ -7,10 +7,10 @@
 .board-grid {
   display: grid;
   grid-template-columns: repeat(8, 1fr);
-  border: 2px solid #5A2C28;
+  border: var(--border-width) solid var(--color-border);
-  border-radius: 10px 10px 0 0;
+  border-radius: var(--border-radius-md) var(--border-radius-md) 0 0;
   overflow: hidden;
-  background: #5A2C28;
+  background: var(--color-text-primary);
 }
 
 .square {
@@ -41,12 +41,13 @@
   width: 28%;
   height: 28%;
   border-radius: 50%;
-  background: rgba(193, 158, 245, 0.75);
+  background: var(--color-secondary-purple);
-  border: 2px solid #5A2C28;
+  opacity: 0.75;
+  border: var(--border-width) solid var(--color-border);
 }
 
 .square.selected {
-  outline: 3px solid #BA6D4B;
+  outline: 3px solid var(--color-primary);
   outline-offset: -3px;
 }
 
@@ -55,7 +56,7 @@
   width: 100%;
   display: block;
   object-fit: fill;
-  border: 2px solid #5A2C28;
+  border: var(--border-width) solid var(--color-border);
   border-top: 0;
-  border-radius: 0 0 10px 10px;
+  border-radius: 0 0 var(--border-radius-md) var(--border-radius-md);
 }

src/app/components/chess-piece/chess-piece.component.css

@@ -1,6 +1,6 @@
 .piece {
   width: clamp(50px, 11cqh, 160px);
-  height: clamp(50px, 11cqh, 160px);
+  height: clamp(40px, 8cqh, 120px);
   display: block;
   object-fit: contain;
   pointer-events: none;

src/app/components/input-card/input-card.component.css

@@ -0,0 +1,63 @@
+.input-card {
+  background: var(--color-bg-card);
+  border: var(--border-width) solid var(--color-border);
+  border-radius: var(--border-radius-md);
+  padding: var(--size-lg-padding);
+  display: flex;
+  flex-direction: column;
+  gap: var(--size-lg-gap);
+}
+
+.move-card {
+  padding: var(--size-sm-padding);
+  gap: var(--size-sm-gap);
+}
+
+.move-card input {
+  min-height: 45px;
+  padding: var(--size-md-padding);
+}
+
+.input-card label {
+  color: var(--color-text-primary);
+  font-weight: 700;
+  margin-bottom: var(--size-xs);
+}
+
+.input-card textarea {
+  resize: vertical;
+  height: 40px;
+  background-color:lightcyan;
+  border: 3px solid var(--color-border);
+    border-radius: var(--border-radius-sm);
+}
+
+.input-card input {
+  min-width: unset;
+  background-color:lightcyan;
+    border: 3px solid var(--color-border);
+        border-radius: var(--border-radius-sm);
+
+}
+
+.input-card .btn {
+  border: var(--button-border);
+  border-radius: var(--border-radius-sm);
+  background: var(--color-bg-button);
+  color: var(--color-text-primary);
+  padding: var(--button-padding);
+  cursor: pointer;
+  font-weight: 600;
+  transition: background-color 0.2s, color 0.2s;
+}
+
+.input-card .btn:hover {
+  background: var(--color-bg-button-hover);
+  color: var(--color-text-button-hover);
+}
+
+.hint-text {
+  margin: 0;
+  color: var(--color-text-primary);
+  font-size: 0.9rem;
+}

src/app/components/input-card/input-card.component.html

@@ -0,0 +1,31 @@
+<section [ngClass]="['input-card', cardClass]">
+  <label>{{ label }}</label>
+
+  @if (inputType === 'textarea') {
+    <textarea
+      #textareaInput
+      [placeholder]="placeholder"
+      [value]="value"
+      [rows]="rows"
+      (input)="onValueChange(textareaInput.value)"
+      class="form-input"
+    ></textarea>
+  } @else {
+    <input
+      #textInput
+      type="text"
+      [placeholder]="placeholder"
+      [value]="value"
+      (input)="onValueChange(textInput.value)"
+      class="form-input"
+    />
+  }
+
+  <button type="button" class="btn w-100" (click)="onButtonClick()">
+    {{ buttonLabel }}
+  </button>
+
+  @if (hintText) {
+    <p class="hint-text">{{ hintText }}</p>
+  }
+</section>

src/app/components/input-card/input-card.component.ts

@@ -0,0 +1,33 @@
+import { Component, Input, Output, EventEmitter } from '@angular/core';
+import { CommonModule } from '@angular/common';
+import { FormsModule } from '@angular/forms';
+
+@Component({
+  selector: 'app-input-card',
+  standalone: true,
+  imports: [CommonModule, FormsModule],
+  templateUrl: './input-card.component.html',
+  styleUrl: './input-card.component.css',
+})
+export class InputCardComponent {
+  @Input() label: string = '';
+  @Input() placeholder: string = '';
+  @Input() buttonLabel: string = 'Send';
+  @Input() inputType: 'input' | 'textarea' = 'input';
+  @Input() value: string = '';
+  @Input() cardClass: string = '';
+  @Input() hintText: string = '';
+  @Input() rows: number = 4;
+
+  @Output() valueChange = new EventEmitter<string>();
+  @Output() buttonClick = new EventEmitter<void>();
+
+  onValueChange(newValue: string): void {
+    this.value = newValue;
+    this.valueChange.emit(newValue);
+  }
+
+  onButtonClick(): void {
+    this.buttonClick.emit();
+  }
+}

src/app/components/promotion-dialog/promotion-dialog.component.css

@@ -0,0 +1,131 @@
+.promotion-dialog-overlay {
+  position: fixed;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  background: rgba(0, 0, 0, 0.5);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  opacity: 0;
+  visibility: hidden;
+  transition: opacity 0.2s, visibility 0.2s;
+  z-index: 1000;
+
+  &.open {
+    opacity: 1;
+    visibility: visible;
+  }
+}
+
+.promotion-dialog {
+  background: white;
+  border-radius: 8px;
+  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
+  max-width: 400px;
+  width: 90%;
+  animation: slideUp 0.3s ease;
+}
+
+@keyframes slideUp {
+  from {
+    opacity: 0;
+    transform: translateY(20px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.promotion-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 20px;
+  border-bottom: 1px solid #e0e0e0;
+
+  h3 {
+    margin: 0;
+    font-size: 18px;
+    font-weight: 600;
+    color: #333;
+  }
+
+  .close-btn {
+    background: none;
+    border: none;
+    font-size: 24px;
+    cursor: pointer;
+    color: #999;
+    padding: 0;
+    width: 30px;
+    height: 30px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    transition: color 0.2s;
+
+    &:hover {
+      color: #333;
+    }
+  }
+}
+
+.promotion-body {
+  padding: 20px;
+}
+
+.promotion-prompt {
+  margin: 0 0 20px 0;
+  text-align: center;
+  color: #666;
+  font-size: 14px;
+}
+
+.promotion-options {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 12px;
+}
+
+.promotion-button {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 8px;
+  padding: 16px;
+  background: #f5f5f5;
+  border: 2px solid #ddd;
+  border-radius: 6px;
+  cursor: pointer;
+  transition: all 0.2s;
+  font-family: inherit;
+
+  &:hover {
+    background: #e8e8e8;
+    border-color: #999;
+    transform: translateY(-2px);
+    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
+  }
+
+  &:active {
+    transform: translateY(0);
+    box-shadow: none;
+  }
+
+  .piece-symbol {
+    font-size: 32px;
+    line-height: 1;
+  }
+
+  .piece-label {
+    font-size: 12px;
+    font-weight: 500;
+    color: #666;
+    text-transform: uppercase;
+    letter-spacing: 0.5px;
+  }
+}

src/app/components/promotion-dialog/promotion-dialog.component.html

@@ -0,0 +1,26 @@
+<div class="promotion-dialog-overlay" [class.open]="isOpen">
+  <div class="promotion-dialog">
+    <div class="promotion-header">
+      <h3>Pawn Promotion</h3>
+      <button class="close-btn" (click)="close()" aria-label="Close">&times;</button>
+    </div>
+    
+    <div class="promotion-body">
+      <p class="promotion-prompt">Choose a piece to promote your pawn to:</p>
+      
+      <div class="promotion-options">
+        @for (piece of promotionPieces; track piece.type) {
+          <button
+            class="promotion-button"
+            [attr.data-piece]="piece.type"
+            (click)="selectPromotion(piece.type)"
+            [title]="piece.label"
+          >
+            <span class="piece-symbol">{{ piece.symbol }}</span>
+            <span class="piece-label">{{ piece.label }}</span>
+          </button>
+        }
+      </div>
+    </div>
+  </div>
+</div>

src/app/components/promotion-dialog/promotion-dialog.component.ts

@@ -0,0 +1,39 @@
+import { Component, EventEmitter, Input, Output } from '@angular/core';
+import { CommonModule } from '@angular/common';
+
+type PromotionPieceType = 'queen' | 'rook' | 'bishop' | 'knight';
+interface PromotionPieceOption {
+  type: PromotionPieceType;
+  label: string;
+  symbol: string;
+}
+
+@Component({
+  selector: 'app-promotion-dialog',
+  standalone: true,
+  imports: [CommonModule],
+  templateUrl: './promotion-dialog.component.html',
+  styleUrl: './promotion-dialog.component.css'
+})
+export class PromotionDialogComponent {
+  @Input() isOpen = false;
+  @Output() promotionSelected = new EventEmitter<PromotionPieceType>();
+  @Output() closed = new EventEmitter<void>();
+
+  promotionPieces: PromotionPieceOption[] = [
+    { type: 'queen', label: 'Queen', symbol: '♕' },
+    { type: 'rook', label: 'Rook', symbol: '♖' },
+    { type: 'bishop', label: 'Bishop', symbol: '♗' },
+    { type: 'knight', label: 'Knight', symbol: '♘' }
+  ];
+
+  selectPromotion(type: PromotionPieceType): void {
+    this.promotionSelected.emit(type);
+    this.isOpen = false;
+  }
+
+  close(): void {
+    this.closed.emit();
+    this.isOpen = false;
+  }
+}

src/app/pages/game/game.component.css

@@ -1,38 +1,38 @@
 .game-shell {
   min-height: 100dvh;
-  padding: clamp(0.75rem, 2vw, 1.5rem);
+  padding: clamp(var(--size-md), 2vw, var(--size-xl));
 }
 
 .game-card {
   max-width: 1400px;
   margin: 0 auto;
-  background: #F3C8A0;
+  background: var(--color-bg-main);
-  border: 2px solid #5A2C28;
+  border: var(--border-width) solid var(--color-border);
-  border-radius: 12px;
+  border-radius: var(--border-radius-lg);
-  padding: clamp(1rem, 2vw, 1.5rem);
+  padding: clamp(var(--size-lg), 2vw, var(--size-xl));
-  box-shadow: 0 8px 24px rgba(90, 44, 40, 0.2);
+  box-shadow: var(--shadow-md);
 }
 
 header {
-  margin-bottom: 1.5rem;
+  margin-bottom: var(--size-xl);
 }
 
 h1,
 h2 {
-  color: #5A2C28;
+  color: var(--color-text-primary);
-  margin: 0 0 0.5rem;
+  margin: 0 0 var(--size-md);
-  font-size: clamp(1.5rem, 4vw, 2rem);
+  font-size: var(--heading-h1);
 }
 
 .meta {
-  color: #5A2C28;
+  color: var(--color-text-primary);
   font-size: 0.95rem;
 }
 
 .back-link {
   display: inline-block;
-  margin-bottom: 0.5rem;
+  margin-bottom: var(--size-sm);
-  color: #5A2C28;
+  color: var(--color-text-primary);
   text-decoration: none;
   font-weight: 600;
 }
@@ -42,25 +42,19 @@ h2 {
 }
 
 .top-section {
-  background: #F3C8A0;
+  display: grid;
-  padding: 0.75rem;
+  gap: var(--size-md);
-  border-radius: 8px;
+  margin-top: var(--size-sm);
-  border: 1px solid #5A2C28;
+  flex: 0 0 auto;
 }
 
-.move-form {
+.move-card {
-  align-items: center;
+  padding: var(--size-lg-padding);
 }
 
-.move-form label {
+.move-card .btn {
-  color: #5A2C28;
+  align-self: flex-start;
-  font-weight: 600;
+  width: auto;
-  white-space: nowrap;
-}
-
-.board-hint {
-  color: #5A2C28;
-  margin: 0;
 }
 
 .center-column {
@@ -68,72 +62,70 @@ h2 {
 }
 
 .board-section {
-  background: #B9DAD1;
+  background: var(--color-bg-board);
-  border: 2px solid #5A2C28;
+  border: var(--border-width) solid var(--color-border);
-  border-radius: 10px;
+  border-radius: var(--border-radius-md);
-  padding: clamp(0.5rem, 1vw, 1rem);
+  padding: clamp(var(--size-sm), 1vw, var(--size-lg));
   min-height: 400px;
   container-type: size;
 }
 
-.import-card {
-  background: #E1EAA9;
-  border: 2px solid #5A2C28;
-  border-radius: 10px;
-  padding: 1rem;
-  display: flex;
-  flex-direction: column;
-  gap: 0.75rem;
-}
-
-.import-card label {
-  color: #5A2C28;
-  font-weight: 700;
-  margin-bottom: 0.25rem;
-}
-
-.import-card textarea {
-  border: 2px solid #5A2C28;
-  border-radius: 8px;
-  background: #B9DAD1;
-  padding: 0.6rem 0.75rem;
-  resize: vertical;
-  min-height: 100px;
-  font-family: inherit;
-}
-
-.import-card input {
-  border: 2px solid #5A2C28;
-  border-radius: 8px;
-  background: #B9DAD1;
-  padding: 0.6rem 0.75rem;
-  font-family: inherit;
-}
-
-.btn {
-  border: 2px solid #5A2C28;
-  border-radius: 8px;
-  background: #C19EF5;
-  color: #5A2C28;
-  padding: 0.6rem 1rem;
-  cursor: pointer;
-  font-weight: 600;
-  transition: background-color 0.2s, color 0.2s;
-}
-
-.btn:hover {
-  background: #BA6D4B;
-  color: #F3C8A0;
-}
-
 .alert {
-  border-radius: 8px;
+  border-radius: var(--border-radius-sm);
-  border: 2px solid #5A2C28;
+  border: var(--border-width) solid var(--color-border);
+}
+
+.game-completion-alert {
+  background: linear-gradient(135deg, var(--color-secondary-mint, #B9DAD1) 0%, var(--color-secondary-blue, #B9C2DA) 100%);
+  border: 2px solid var(--color-secondary-mint, #B9DAD1) !important;
+  border-radius: var(--border-radius-lg) !important;
+  padding: var(--size-xl-padding) !important;
+  box-shadow: 0 8px 16px rgba(185, 218, 209, 0.3);
+  animation: slideIn 0.4s ease-out;
+}
+
+@keyframes slideIn {
+  from {
+    opacity: 0;
+    transform: translateY(-20px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.completion-title {
+  color: var(--color-text-primary);
+  font-size: 1.75rem;
+  margin: 0 0 var(--size-md) 0;
+  font-weight: 700;
+  text-align: center;
+}
+
+.completion-subtitle {
+  text-align: center;
+  color: var(--color-text-primary);
+  font-size: 1rem;
+}
+
+.completion-link {
+  color: var(--color-text-primary);
+  text-decoration: none;
+  font-weight: 600;
+  border-bottom: 2px solid var(--color-text-primary);
+  transition: all 0.3s ease;
+  padding-bottom: 2px;
+}
+
+.completion-link:hover {
+  color: var(--color-secondary-blue);
+  border-bottom-color: var(--color-secondary-blue);
 }
 
 @media (max-width: 991px) {
   .game-card {
-    padding: clamp(0.75rem, 1.5vw, 1rem);
+    padding: clamp(var(--size-md), 1.5vw, var(--size-lg));
   }
 
   .board-section {
@@ -142,26 +134,26 @@ h2 {
 
   h1,
   h2 {
-    font-size: clamp(1.25rem, 3vw, 1.75rem);
+    font-size: var(--heading-h1-tablet);
   }
 }
 
 @media (max-width: 768px) {
   .game-shell {
-    padding: clamp(0.5rem, 1.5vw, 1rem);
+    padding: clamp(var(--size-sm), 1.5vw, var(--size-lg));
   }
 
   .game-card {
-    padding: clamp(0.5rem, 1vw, 0.75rem);
+    padding: clamp(var(--size-sm), 1vw, var(--size-md));
   }
 
   header {
-    margin-bottom: 1rem;
+    margin-bottom: var(--size-lg);
   }
 
   h1,
   h2 {
-    font-size: 1.25rem;
+    font-size: var(--heading-h1-mobile);
   }
 
   .meta {
@@ -169,61 +161,31 @@ h2 {
   }
 
   .top-section {
-    padding: 0.5rem;
+    gap: var(--size-xs);
-    margin-bottom: 0.75rem;
+    margin-bottom: var(--size-xs);
-  }
-
-  .move-form {
-    flex-wrap: wrap;
-  }
-
-  .move-form label {
-    flex-basis: 100%;
-    margin-bottom: 0.5rem;
   }
 
   .board-section {
     min-height: 300px;
   }
-
-  .import-card {
-    padding: 0.75rem;
-    gap: 0.5rem;
-  }
-
-  .import-card label {
-    font-size: 0.9rem;
-  }
-
-  .import-card textarea,
-  .import-card input {
-    min-height: 70px;
-    font-size: 0.9rem;
-    padding: 0.5rem;
-  }
-
-  .btn {
-    padding: 0.5rem 0.75rem;
-    font-size: 0.9rem;
-  }
 }
 
 @media (max-width: 480px) {
   .game-shell {
-    padding: 0.5rem;
+    padding: var(--size-sm);
   }
 
   .game-card {
-    padding: 0.5rem;
+    padding: var(--size-sm);
-    border-radius: 8px;
+    border-radius: var(--border-radius-md);
   }
 
   header {
-    margin-bottom: 0.75rem;
+    margin-bottom: var(--size-md);
   }
 
   h1 {
-    font-size: 1.1rem;
+    font-size: var(--heading-h1-small);
   }
 
   .meta {
@@ -231,23 +193,11 @@ h2 {
   }
 
   .top-section {
-    padding: 0.4rem;
+    gap: var(--size-xs-gap);
-    margin-bottom: 0.5rem;
+    margin-bottom: var(--size-xs);
   }
 
   .board-section {
     min-height: 250px;
   }
-
-  .import-card {
-    padding: 0.5rem;
-    gap: 0.35rem;
-  }
-
-  .import-card textarea,
-  .import-card input {
-    min-height: 50px;
-    font-size: 0.8rem;
-    padding: 0.4rem;
-  }
 }

src/app/pages/game/game.component.html

@@ -1,4 +1,10 @@
 <main class="game-shell">
+  <app-promotion-dialog
+    [isOpen]="facade.isPromotionDialogOpen"
+    (promotionSelected)="facade.onPromotionSelected($event)"
+    (closed)="facade.onPromotionClosed()"
+  />
+
   <section class="game-card">
     <header class="mb-3">
       <a routerLink="/" class="back-link">Back</a>
@@ -9,41 +15,33 @@
     @if (facade.loading) {
       <p>Loading game state...</p>
     } @else if (facade.state) {
+      @if (facade.isGameFinished && facade.gameCompletionMessage) {
+        <div class="game-completion-alert alert alert-success mb-3">
+          <h2 class="completion-title">{{ facade.gameCompletionMessage }}</h2>
+          <p class="completion-subtitle mb-0">
+            <a routerLink="/" class="completion-link">Start a new game</a>
+          </p>
+        </div>
+      }
       <div class="container-fluid">
         <div class="row g-3">
           <!-- Left Sidebar - FEN Import -->
           <div class="col-lg-3 col-md-6 col-12 order-lg-1 order-2">
-            <aside class="import-card fen-card h-100">
+            <app-input-card
-              <label for="fenImport">Import FEN</label>
+              label="Import FEN"
-              <textarea
-                id="fenImport"
-                name="fenImport"
-                [(ngModel)]="facade.fenInput"
-                rows="4"
               placeholder="rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
-              ></textarea>
+              buttonLabel="Load FEN"
-              <button type="button" class="btn w-100" (click)="facade.importFen()">Load FEN</button>
+              inputType="textarea"
-            </aside>
+              [value]="facade.fenInput"
+              cardClass="fen-card"
+              (valueChange)="facade.fenInput = $event"
+              (buttonClick)="facade.importFen()"
+            />
           </div>
 
           <!-- Center - Chess Board -->
           <div class="col-lg-6 col-md-12 col-12 order-lg-2 order-1">
             <section class="center-column d-flex flex-column h-100">
-              <div class="top-section mb-3">
-                <form class="move-form d-flex flex-wrap gap-2 mb-2" (ngSubmit)="facade.submitMove()">
-                  <label for="uciMove" class="form-label mb-0">Play move (UCI)</label>
-                  <input 
-                    id="uciMove" 
-                    name="uciMove" 
-                    class="form-control flex-grow-1"
-                    [(ngModel)]="facade.moveInput" 
-                    placeholder="e2e4" 
-                  />
-                  <button type="submit" class="btn">Send Move</button>
-                </form>
-                <p class="board-hint small mb-0">Click your piece to highlight legal targets.</p>
-              </div>
-
               <div class="board-section flex-grow-1 d-flex align-items-center justify-content-center">
                 <app-chess-board
                   [fen]="facade.state.fen"
@@ -52,22 +50,35 @@
                   (squareSelected)="facade.onBoardSquareSelected($event)"
                 />
               </div>
+
+              <section class="top-section">
+                <app-input-card
+                  label="Play move (UCI)"
+                  placeholder="e2e4"
+                  buttonLabel="Send Move"
+                  inputType="input"
+                  [value]="facade.moveInput"
+                  cardClass="move-card"
+                  hintText="Click your piece to highlight legal targets."
+                  (valueChange)="facade.moveInput = $event"
+                  (buttonClick)="facade.submitMove()"
+                />
+              </section>
             </section>
           </div>
 
           <!-- Right Sidebar - PGN Import -->
           <div class="col-lg-3 col-md-6 col-12 order-lg-3 order-3">
-            <aside class="import-card pgn-card h-100">
+            <app-input-card
-              <label for="pgnImport">Import PGN</label>
+              label="Import PGN"
-              <textarea
-                id="pgnImport"
-                name="pgnImport"
-                [(ngModel)]="facade.pgnInput"
-                rows="4"
               placeholder="1. e4 e5 2. Nf3 Nc6 *"
-              ></textarea>
+              buttonLabel="Load PGN"
-              <button type="button" class="btn w-100" (click)="facade.importPgn()">Load PGN</button>
+              inputType="textarea"
-            </aside>
+              [value]="facade.pgnInput"
+              cardClass="pgn-card"
+              (valueChange)="facade.pgnInput = $event"
+              (buttonClick)="facade.importPgn()"
+            />
           </div>
         </div>
       </div>

src/app/pages/game/game.component.ts

@@ -4,12 +4,14 @@ import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
 import { FormsModule } from '@angular/forms';
 import { ActivatedRoute, RouterLink } from '@angular/router';
 import { ChessBoardComponent } from '../../components/chess-board/chess-board.component';
+import { InputCardComponent } from '../../components/input-card/input-card.component';
+import { PromotionDialogComponent } from '../../components/promotion-dialog/promotion-dialog.component';
 import { GameFacade } from './game.facade';
 
 @Component({
   selector: 'app-game',
   standalone: true,
-  imports: [CommonModule, FormsModule, RouterLink, ChessBoardComponent],
+  imports: [CommonModule, FormsModule, RouterLink, ChessBoardComponent, InputCardComponent, PromotionDialogComponent],
   providers: [GameFacade],
   templateUrl: './game.component.html',
   styleUrl: './game.component.css'

src/app/pages/game/game.facade.ts

@@ -1,11 +1,13 @@
 import { DestroyRef, Injectable, OnDestroy, inject } from '@angular/core';
-import { Router } from '@angular/router';
 import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
-import { interval, startWith, Subscription, switchMap } from 'rxjs';
-import { getPieceAtSquare, isPieceColor } from '../../core/chess/fen.utils';
 import { getErrorMessage } from '../../core/http/error-message.util';
 import { GameFull, GameState, GameStreamEvent, LegalMove } from '../../models/game.models';
 import { GameApiService } from '../../services/game-api.service';
+import { BotMoveService } from '../../services/bot-move.service';
+import { GameCompletionService } from '../../services/game-completion.service';
+import { GameImportService } from '../../services/game-import.service';
+import { BoardSelectionService, BoardSelection } from '../../services/board-selection.service';
+import { GameStreamService } from '../../services/game-stream.service';
 
 @Injectable()
 export class GameFacade implements OnDestroy {
@@ -16,25 +18,42 @@ export class GameFacade implements OnDestroy {
   fenInput = '';
   pgnInput = '';
   loading = true;
-  selectedSquare: string | null = null;
+  gameCompletionMessage = '';
-  highlightedSquares: string[] = [];
+  isGameFinished = false;
+  isPromotionDialogOpen = false;
+
+  private boardSelection: BoardSelection = {
+    selectedSquare: null,
+    highlightedSquares: [],
+    selectedSquareMoves: []
+  };
+  private pendingPromotionMoves: LegalMove[] = [];
 
-  private selectedSquareMoves: LegalMove[] = [];
-  private readonly router = inject(Router);
   private readonly gameApi = inject(GameApiService);
   private readonly destroyRef = inject(DestroyRef);
-  private streamSubscription: Subscription | null = null;
+  private readonly botMoveService = inject(BotMoveService);
-  private pollSubscription: Subscription | null = null;
+  private readonly completionService = inject(GameCompletionService);
-
+  private readonly importService = inject(GameImportService);
-  ngOnDestroy(): void {
+  private readonly boardSelectionService = inject(BoardSelectionService);
-    this.streamSubscription?.unsubscribe();
+  private readonly streamService = inject(GameStreamService);
-    this.pollSubscription?.unsubscribe();
-  }
 
   get state(): GameState | null {
     return this.game?.state ?? null;
   }
 
+  get selectedSquare(): string | null {
+    return this.boardSelection.selectedSquare;
+  }
+
+  get highlightedSquares(): string[] {
+    return this.boardSelection.highlightedSquares;
+  }
+
+  ngOnDestroy(): void {
+    this.streamService.cleanup();
+    this.botMoveService.cleanup();
+  }
+
   setGameId(gameId: string): void {
     this.gameId = gameId;
     this.loadGame();
@@ -45,36 +64,45 @@ export class GameFacade implements OnDestroy {
       return;
     }
 
-    if (this.selectedSquare && this.highlightedSquares.includes(square)) {
+    // Handle move selection
-      const selectedMove = this.selectedSquareMoves.find((move) => move.to === square);
+    if (this.boardSelection.selectedSquare && this.boardSelection.highlightedSquares.includes(square)) {
+      const selectedMove = this.boardSelection.selectedSquareMoves.find((move) => move.to === square);
       if (selectedMove) {
+        // If multiple promotion outcomes exist for the target, ask player to choose one.
+        const promotionMoves = this.boardSelection.selectedSquareMoves.filter(
+          (move) => move.to === square && !!move.promotion
+        );
+        if (promotionMoves.length > 0) {
+          this.pendingPromotionMoves = promotionMoves;
+          this.isPromotionDialogOpen = true;
+          return;
+        }
         this.moveInput = selectedMove.uci;
         this.submitMove();
       }
       return;
     }
 
-    const piece = getPieceAtSquare(this.state.fen, square);
+    // Load moves for selected square
-    if (!piece || !isPieceColor(piece, this.state.turn)) {
-      this.clearSelection();
-      return;
-    }
-
     this.errorMessage = '';
-    this.gameApi
+    const newSelection = this.boardSelectionService.handleSquareSelection(
-      .getLegalMoves(this.gameId, square)
+      square,
-      .pipe(takeUntilDestroyed(this.destroyRef))
+      this.gameId,
-      .subscribe({
+      this.state,
-        next: (response) => {
+      this.boardSelection,
-          this.selectedSquare = square;
+      (moves) => {
-          this.selectedSquareMoves = response.moves;
+        this.boardSelection = {
-          this.highlightedSquares = response.moves.map((move) => move.to);
+          selectedSquare: square,
+          highlightedSquares: moves.map((move) => move.to),
+          selectedSquareMoves: moves
+        };
       },
-        error: () => {
+      (error) => {
-          this.clearSelection();
+        this.errorMessage = error;
-          this.errorMessage = 'Could not load legal moves for selected square.';
+        this.boardSelection = this.boardSelectionService.clearSelection();
       }
-      });
+    );
+    this.boardSelection = newSelection;
   }
 
   submitMove(): void {
@@ -91,9 +119,25 @@ export class GameFacade implements OnDestroy {
         next: (state) => {
           if (this.game) {
             this.game = { ...this.game, state };
+            this.updateGameCompletion();
           }
           this.moveInput = '';
-          this.clearSelection();
+          this.boardSelection = this.boardSelectionService.clearSelection();
+          this.botMoveService.tryMakeBotMove(
+            this.gameId,
+            this.game,
+            this.state,
+            (updatedState) => {
+              if (this.game) {
+                this.game = { ...this.game, state: updatedState };
+                this.updateGameCompletion();
+              }
+              this.boardSelection = this.boardSelectionService.clearSelection();
+            },
+            (error) => {
+              this.errorMessage = error;
+            }
+          );
         },
         error: (error) => {
           this.errorMessage = getErrorMessage(error, 'Move rejected.');
@@ -101,59 +145,61 @@ export class GameFacade implements OnDestroy {
       });
   }
 
-  importFen(): void {
+  onPromotionSelected(promotionPiece: 'queen' | 'rook' | 'bishop' | 'knight'): void {
-    const fen = this.fenInput.trim();
+    const selectedPromotionMove = this.pendingPromotionMoves.find((move) => move.promotion === promotionPiece);
-    if (!fen) {
+    if (!selectedPromotionMove) {
-      this.errorMessage = 'Please provide a FEN string.';
+      this.errorMessage = 'Selected promotion move is unavailable.';
+      this.isPromotionDialogOpen = false;
+      this.pendingPromotionMoves = [];
       return;
     }
 
+    this.moveInput = selectedPromotionMove.uci;
+    this.isPromotionDialogOpen = false;
+    this.boardSelection = this.boardSelectionService.clearSelection();
+    this.pendingPromotionMoves = [];
+    this.submitMove();
+  }
+
+  onPromotionClosed(): void {
+    this.isPromotionDialogOpen = false;
+    this.boardSelection = this.boardSelectionService.clearSelection();
+    this.pendingPromotionMoves = [];
+  }
+
+  importFen(): void {
     this.errorMessage = '';
-    this.gameApi
+    this.importService.importFen(
-      .importFen(fen)
+      this.fenInput,
-      .pipe(takeUntilDestroyed(this.destroyRef))
+      () => {
-      .subscribe({
-        next: (game) => {
         this.fenInput = '';
         this.pgnInput = '';
-          void this.router.navigate(['/game', game.gameId]);
       },
-        error: (error) => {
+      (error) => {
-          this.errorMessage = getErrorMessage(error, 'FEN import failed.');
+        this.errorMessage = error;
       }
-      });
+    );
   }
 
   importPgn(): void {
-    const pgn = this.pgnInput.trim();
-    if (!pgn) {
-      this.errorMessage = 'Please provide a PGN string.';
-      return;
-    }
-
     this.errorMessage = '';
-    this.gameApi
+    this.importService.importPgn(
-      .importPgn(pgn)
+      this.pgnInput,
-      .pipe(takeUntilDestroyed(this.destroyRef))
+      () => {
-      .subscribe({
-        next: (game) => {
         this.pgnInput = '';
         this.fenInput = '';
-          void this.router.navigate(['/game', game.gameId]);
       },
-        error: (error) => {
+      (error) => {
-          this.errorMessage = getErrorMessage(error, 'PGN import failed.');
+        this.errorMessage = error;
       }
-      });
+    );
   }
 
   private loadGame(): void {
     this.loading = true;
     this.errorMessage = '';
-    this.clearSelection();
+    this.boardSelection = this.boardSelectionService.clearSelection();
-    this.streamSubscription?.unsubscribe();
+    this.streamService.cleanup();
-    this.pollSubscription?.unsubscribe();
-    this.pollSubscription = null;
 
     this.gameApi
       .getGame(this.gameId)
@@ -162,7 +208,9 @@ export class GameFacade implements OnDestroy {
         next: (game) => {
           this.game = game;
           this.loading = false;
-          this.startStream();
+          this.updateGameCompletion();
+          this.startStreaming();
+          this.tryMakeBotMove();
         },
         error: (error) => {
           this.errorMessage = getErrorMessage(error, `Could not load game ${this.gameId}.`);
@@ -171,57 +219,32 @@ export class GameFacade implements OnDestroy {
       });
   }
 
-  private startStream(): void {
+  private startStreaming(): void {
-    this.streamSubscription = this.gameApi
+    this.streamService.startStreaming(
-      .streamGame(this.gameId)
+      this.gameId,
-      .pipe(takeUntilDestroyed(this.destroyRef))
+      (event) => this.applyStreamEvent(event),
-      .subscribe({
+      () => {
-        next: (event) => this.applyStreamEvent(event),
-        error: () => {
         this.errorMessage = 'Live stream disconnected. Falling back to polling.';
-          this.startPolling();
-        },
-        complete: () => {
-          this.errorMessage = 'Live stream ended. Falling back to polling.';
-          this.startPolling();
       }
-      });
+    );
-  }
-
-  private startPolling(): void {
-    if (this.pollSubscription) {
-      return;
-    }
-
-    this.pollSubscription = interval(1500)
-      .pipe(
-        startWith(0),
-        switchMap(() => this.gameApi.getGame(this.gameId)),
-        takeUntilDestroyed(this.destroyRef)
-      )
-      .subscribe({
-        next: (game) => {
-          const previousMoves = this.game?.state.moves.join(',') ?? '';
-          this.game = game;
-          if (previousMoves !== game.state.moves.join(',')) {
-            this.clearSelection();
-          }
-        }
-      });
   }
 
   private applyStreamEvent(event: GameStreamEvent): void {
     if (event.type === 'gameFull') {
       this.game = event.game;
-      this.clearSelection();
+      this.boardSelection = this.boardSelectionService.clearSelection();
+      this.updateGameCompletion();
+      this.tryMakeBotMove();
       return;
     }
 
     if (event.type === 'gameState' && this.game) {
       const moveCountBefore = this.game.state.moves.length;
       this.game = { ...this.game, state: event.state };
+      this.updateGameCompletion();
       if (event.state.moves.length !== moveCountBefore) {
-        this.clearSelection();
+        this.boardSelection = this.boardSelectionService.clearSelection();
+        this.tryMakeBotMove();
       }
       return;
     }
@@ -231,9 +254,27 @@ export class GameFacade implements OnDestroy {
     }
   }
 
-  private clearSelection(): void {
+  private tryMakeBotMove(): void {
-    this.selectedSquare = null;
+    this.botMoveService.tryMakeBotMove(
-    this.selectedSquareMoves = [];
+      this.gameId,
-    this.highlightedSquares = [];
+      this.game,
+      this.state,
+      (updatedState) => {
+        if (this.game) {
+          this.game = { ...this.game, state: updatedState };
+          this.updateGameCompletion();
+        }
+        this.boardSelection = this.boardSelectionService.clearSelection();
+      },
+      (error) => {
+        this.errorMessage = error;
+      }
+    );
+  }
+
+  private updateGameCompletion(): void {
+    const completion = this.completionService.getGameCompletion(this.game, this.state);
+    this.gameCompletionMessage = completion.message;
+    this.isGameFinished = completion.isFinished;
   }
 }

src/app/pages/welcome/welcome.component.css

@@ -1,99 +1,459 @@
 .welcome-shell {
   min-height: 100vh;
-  display: grid;
+  display: flex;
-  place-items: center;
+  flex-direction: column;
-  padding: 2rem;
+  align-items: center;
+  justify-content: center;
+  padding: var(--size-xl);
+  position: relative;
+}
+
+.theme-toggle-container {
+  position: absolute;
+  top: 20px;
+  right: 20px;
+  z-index: 100;
+}
+
+.switch {
+  display: inline-block;
+  position: relative;
+}
+
+.switch__input {
+  clip: rect(1px, 1px, 1px, 1px);
+  clip-path: inset(50%);
+  height: 1px;
+  width: 1px;
+  margin: -1px;
+  overflow: hidden;
+  padding: 0;
+  position: absolute;
+}
+
+.switch__label {
+  position: relative;
+  display: inline-block;
+  width: 120px;
+  height: 60px;
+  background-color: #2B2B2B;
+  border: 5px solid #5B5B5B;
+  border-radius: 9999px;
+  cursor: pointer;
+  transition: all 0.4s cubic-bezier(.46,.03,.52,.96);
+}
+
+.switch__indicator {
+  position: absolute;
+  top: 50%;
+  left: 50%;
+  transform: translate(-50%, -50%) translateX(-72%);
+  display: block;
+  width: 40px;
+  height: 40px;
+  background-color: #7B7B7B;
+  border-radius: 9999px;
+  box-shadow: 10px 0px 0 0 rgba(0, 0, 0, 0.2) inset;
+  transition: all 0.4s cubic-bezier(.46,.03,.52,.96);
+}
+
+.switch__indicator::before,
+.switch__indicator::after {
+  position: absolute;
+  content: '';
+  display: block;
+  background-color: #FFFFFF;
+  border-radius: 9999px;
+  transition: all 0.4s cubic-bezier(.46,.03,.52,.96);
+}
+
+.switch__indicator::before {
+  top: 7px;
+  left: 7px;
+  width: 9px;
+  height: 9px;
+  opacity: 0.6;
+}
+
+.switch__indicator::after {
+  bottom: 8px;
+  right: 6px;
+  width: 14px;
+  height: 14px;
+  opacity: 0.8;
+}
+
+.switch__decoration {
+  position: absolute;
+  top: 65%;
+  left: 50%;
+  display: block;
+  width: 5px;
+  height: 5px;
+  background-color: #FFFFFF;
+  border-radius: 9999px;
+  animation: twinkle-stars 0.8s infinite -0.6s;
+  transition: all 0.4s cubic-bezier(.46,.03,.52,.96);
+}
+
+.switch__decoration::before,
+.switch__decoration::after {
+  position: absolute;
+  display: block;
+  content: '';
+  width: 5px;
+  height: 5px;
+  background-color: #FFFFFF;
+  border-radius: 9999px;
+}
+
+.switch__decoration::before {
+  top: -20px;
+  left: 10px;
+  opacity: 1;
+  animation: twinkle-stars 0.6s infinite;
+}
+
+.switch__decoration::after {
+  top: -7px;
+  left: 30px;
+  animation: twinkle-stars 0.6s infinite -0.2s;
+}
+
+@keyframes twinkle-stars {
+  50% { opacity: 0.2; }
+}
+
+.switch__input:checked + .switch__label {
+  background-color: #8FB5F5;
+  border-color: #347CF8;
+}
+
+.switch__input:checked + .switch__label .switch__indicator {
+  background-color: #ECD21F;
+  box-shadow: none;
+  transform: translate(-50%, -50%) translateX(72%);
+}
+
+.switch__input:checked + .switch__label .switch__indicator::before,
+.switch__input:checked + .switch__label .switch__indicator::after {
+  display: none;
+}
+
+.switch__input:checked + .switch__label .switch__decoration {
+  top: 50%;
+  transform: translate(0%, -50%);
+  animation: cloud 8s linear infinite;
+  width: 20px;
+  height: 20px;
+}
+
+.switch__input:checked + .switch__label .switch__decoration::before {
+  width: 10px;
+  height: 10px;
+  top: auto;
+  bottom: 0;
+  left: -8px;
+  animation: none;
+}
+
+.switch__input:checked + .switch__label .switch__decoration::after {
+  width: 15px;
+  height: 15px;
+  top: auto;
+  bottom: 0;
+  left: 16px;
+  animation: none;
+}
+
+.switch__input:checked + .switch__label .switch__decoration,
+.switch__input:checked + .switch__label .switch__decoration::before,
+.switch__input:checked + .switch__label .switch__decoration::after {
+  border-radius: 9999px 9999px 0 0;
+}
+
+.switch__input:checked + .switch__label .switch__decoration::after {
+  border-bottom-right-radius: 9999px;
+}
+
+@keyframes cloud {
+  0% { transform: translate(0%, -50%); }
+  50% { transform: translate(-50%, -50%); }
+  100% { transform: translate(0%, -50%); }
+}
+
+.clouds-container {
+  display: flex;
+  justify-content: center;
+  align-items: flex-start;
+  gap: 60px;
+  width: 100%;
+  max-width: 900px;
+  margin-bottom: var(--size-xl);
+  position: relative;
+  z-index: 1;
+}
+
+.plane {
+  position: relative;
+  width: 320px;
+  height: 140px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.12));
+}
+
+.plane-body {
+  width: 240%;
+  height: 240%;
+  object-fit: contain;
+  position: absolute;
+}
+
+.plane-gif {
+  width: 70px;
+  height: 70px;
+  object-fit: contain;
+  z-index: 10;
+  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.15));
+  position: relative;
+  transform: translateX(-25px) translateY(15px);
+}
+
+.cloud {
+  position: relative;
+  width: 220px;
+  height: 90px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.12));
+}
+
+.cloud::before {
+  content: '';
+  position: absolute;
+  width: 90px;
+  height: 90px;
+  background: #ffffff;
+  border-radius: 50%;
+  top: 0;
+  left: 0;
+  box-shadow: 55px 0 0 9px #ffffff, 110px 0 0 5px #ffffff, 27px -18px 0 13px #ffffff, 82px -13px 0 11px #ffffff;
+}
+
+.cloud::after {
+  content: '';
+  position: absolute;
+  width: 220px;
+  height: 45px;
+  background: #ffffff;
+  border-radius: 50px;
+  bottom: 0;
+  left: 0;
+}
+
+.cloud-gif {
+  width: 150px;
+  height: 100px;
+  object-fit: contain;
+  z-index: 10;
+  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.15));
+  position: relative;
+}
+
+.gif-with-halo {
+  position: relative;
+  display: inline-block;
+}
+
+.gif-with-halo::before {
+  content: '';
+  position: absolute;
+  top: -10px;
+  left: 50%;
+  transform: translateX(-50%);
+  width: 75px;
+  height: 15px;
+  border: 2px solid rgba(255, 215, 0, 0.7);
+  border-radius: 50%;
+  box-shadow: 0 0 8px rgba(255, 215, 0, 0.5);
+  z-index: 5;
 }
 
 .welcome-card {
   width: min(900px, 100%);
-  border-radius: 12px;
+  border-radius: var(--border-radius-lg);
-  border: 2px solid #5A2C28;
+  border: var(--border-width) solid var(--color-border);
-  background: #F3C8A0;
+  background: var(--color-bg-main);
-  padding: 2rem;
+  padding: var(--size-xl-padding);
-  box-shadow: 0 8px 24px rgba(90, 44, 40, 0.2);
+  box-shadow: var(--shadow-md);
 }
 
 h1 {
-  margin: 0 0 0.25rem;
+  margin: 0 0 var(--size-xs);
-  color: #5A2C28;
+  color: var(--color-text-primary);
+  font-size: var(--heading-h1);
 }
 
 p {
-  margin: 0 0 1.25rem;
+  margin: 0 0 var(--size-lg);
 }
 
 .mode-grid {
   display: grid;
   grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
-  gap: 1rem;
+  gap: var(--size-xl-gap);
 }
 
 .mode {
-  border: 2px solid #5A2C28;
+  border: var(--border-width) solid var(--color-border);
-  border-radius: 10px;
+  border-radius: var(--border-radius-md);
-  padding: 1rem;
+  padding: var(--size-lg-padding);
   text-align: left;
   display: grid;
-  gap: 0.25rem;
+  gap: var(--size-xs);
 }
 
 .mode span {
   font-size: 1.15rem;
-  color: #5A2C28;
+  color: var(--color-text-primary);
 }
 
 .mode small {
-  color: #5A2C28;
+  color: var(--color-text-primary);
   opacity: 0.9;
 }
 
 .mode-active {
-  background: #B9DAD1;
+  background: var(--color-secondary-mint);
   cursor: pointer;
 }
 
 .mode-active:hover:enabled {
-  background: #B9C2DA;
+  background: var(--color-secondary-blue);
 }
 
 .mode-disabled {
-  background: #E1EAA9;
+  background: var(--color-bg-card);
   opacity: 0.75;
 }
 
 .error {
-  color: #5A2C28;
+  color: var(--color-text-primary);
   font-weight: 700;
-  margin-top: 1rem;
+  margin-top: var(--size-xl);
+}
+
+.plane-left {
+  animation: float 3s ease-in-out infinite;
+}
+
+.cloud-left {
+  animation: float 3s ease-in-out infinite;
+  animation-delay: 0.25s;
+}
+
+.cloud-right {
+  animation: float 3s ease-in-out infinite;
+  animation-delay: 0.5s;
+}
+
+@keyframes float {
+  0%, 100% {
+    transform: translateY(0px);
+  }
+  50% {
+    transform: translateY(-15px);
+  }
 }
 
 @media (max-width: 768px) {
+  .theme-toggle-container {
+    top: 10px;
+    right: 10px;
+  }
+
+  .switch__label {
+    width: 100px;
+    height: 50px;
+  }
+
+  .switch__indicator {
+    width: 33px;
+    height: 33px;
+  }
+
   .welcome-shell {
-    padding: 1rem;
+    padding: var(--size-lg);
+  }
+
+  .clouds-container {
+    gap: 30px;
+    margin-bottom: var(--size-lg);
+  }
+
+  .plane {
+    width: 240px;
+    height: 110px;
+  }
+
+  .plane-gif {
+    width: 55px;
+    height: 55px;
+    transform: translateX(-20px) translateY(12px);
+  }
+
+  .cloud {
+    width: 170px;
+    height: 75px;
+  }
+
+  .cloud::before {
+    width: 65px;
+    height: 65px;
+    box-shadow: 40px 0 0 7px #ffffff, 80px 0 0 3px #ffffff, 20px -13px 0 10px #ffffff, 60px -10px 0 8px #ffffff;
+  }
+
+  .cloud::after {
+    width: 170px;
+    height: 38px;
+  }
+
+  .cloud-gif {
+    width: 140px;
+    height: 140px;
+  }
+
+  .gif-with-halo::before {
+    top: -8px;
+    width: 80px;
+    height: 12px;
+    border: 1.5px solid rgba(255, 215, 0, 0.7);
   }
 
   .welcome-card {
-    padding: 1.5rem;
+    padding: var(--size-xl);
   }
 
   h1 {
-    font-size: 1.5rem;
+    font-size: var(--heading-h1-mobile);
   }
 
   p {
     font-size: 0.875rem;
-    margin: 0 0 1rem;
+    margin: 0 0 var(--size-lg);
   }
 
   .mode-grid {
     grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
-    gap: 0.75rem;
+    gap: var(--size-md-gap);
   }
 
   .mode {
-    padding: 0.75rem;
+    padding: var(--size-md-padding);
-    gap: 0.15rem;
+    gap: var(--size-xs-gap);
   }
 
   .mode span {
@@ -111,22 +471,22 @@ p {
 
 @media (max-width: 480px) {
   .welcome-shell {
-    padding: 0.5rem;
+    padding: var(--size-sm);
   }
 
   .welcome-card {
-    padding: 1rem;
+    padding: var(--size-lg-padding);
-    border-radius: 8px;
+    border-radius: var(--border-radius-md);
   }
 
   h1 {
-    font-size: 1.25rem;
+    font-size: var(--heading-h1-small);
-    margin: 0 0 0.15rem;
+    margin: 0 0 var(--size-xs);
   }
 
   p {
     font-size: 0.8rem;
-    margin: 0 0 0.75rem;
+    margin: 0 0 var(--size-md);
   }
 
   .mode-grid {
@@ -134,10 +494,163 @@ p {
   }
 
   .mode {
-    padding: 0.65rem;
+    padding: var(--size-md-padding);
   }
 
   .mode span {
     font-size: 0.95rem;
   }
 }
+
+.difficulty-selector {
+  grid-column: 1 / -1;
+  background: var(--color-bg-card);
+  border: var(--border-width) solid var(--color-border);
+  border-radius: var(--border-radius-md);
+  padding: var(--size-lg-padding);
+  margin: var(--size-md) 0;
+}
+
+.difficulty-selector p {
+  margin: 0 0 var(--size-md);
+  font-weight: 600;
+}
+
+.difficulty-buttons {
+  display: flex;
+  gap: var(--size-md-gap);
+  flex-wrap: wrap;
+}
+
+.difficulty-btn {
+  flex: 1;
+  min-width: 80px;
+  padding: var(--size-md-padding);
+  border: var(--border-width) solid var(--color-border);
+  border-radius: var(--border-radius-md);
+  cursor: pointer;
+  font-weight: 600;
+  transition: all 0.3s ease;
+}
+
+.difficulty-btn.easy {
+  background: var(--color-success-light, #d4edda);
+  color: var(--color-text-primary);
+}
+
+.difficulty-btn.easy:hover:enabled {
+  background: var(--color-success, #28a745);
+  color: white;
+}
+
+.difficulty-btn.medium {
+  background: var(--color-warning-light, #fff3cd);
+  color: var(--color-text-primary);
+}
+
+.difficulty-btn.medium:hover:enabled {
+  background: var(--color-warning, #ffc107);
+  color: var(--color-text-primary);
+}
+
+.difficulty-btn.hard {
+  background: var(--color-danger-light, #f8d7da);
+  color: var(--color-text-primary);
+}
+
+.difficulty-btn.hard:hover:enabled {
+  background: var(--color-danger, #dc3545);
+  color: white;
+}
+
+.join-game-form {
+  grid-column: 1 / -1;
+  background: var(--color-bg-card);
+  border: var(--border-width) solid var(--color-border);
+  border-radius: var(--border-radius-md);
+  padding: var(--size-lg-padding);
+  margin: var(--size-md) 0;
+}
+
+.join-game-form p {
+  margin: 0 0 var(--size-md);
+  font-weight: 600;
+}
+
+.join-game-input-group {
+  display: flex;
+  gap: var(--size-md-gap);
+  flex-wrap: wrap;
+}
+
+.join-game-input {
+  flex: 1;
+  min-width: 150px;
+  padding: var(--size-md-padding);
+  border: var(--border-width) solid var(--color-border);
+  border-radius: var(--border-radius-md);
+  background: white;
+  color: var(--color-text-primary);
+  font-family: inherit;
+  font-size: 1rem;
+  transition: border-color 0.3s ease;
+}
+
+.join-game-input:focus {
+  outline: none;
+  border-color: var(--color-secondary-mint);
+  box-shadow: 0 0 0 3px rgba(185, 218, 209, 0.2);
+}
+
+.join-game-input:disabled {
+  background: var(--color-bg-card);
+  opacity: 0.6;
+}
+
+.join-game-btn {
+  padding: var(--size-md-padding) var(--size-lg);
+  border: var(--border-width) solid var(--color-border);
+  border-radius: var(--border-radius-md);
+  cursor: pointer;
+  font-weight: 600;
+  font-size: 0.95rem;
+  transition: all 0.3s ease;
+}
+
+.join-game-btn.join {
+  background: var(--color-secondary-mint);
+  color: var(--color-text-primary);
+}
+
+.join-game-btn.join:hover:enabled {
+  background: var(--color-secondary-blue);
+}
+
+.join-game-btn.join:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
+
+.join-game-btn.cancel {
+  background: var(--color-bg-card);
+  color: var(--color-text-primary);
+}
+
+.join-game-btn.cancel:hover:enabled {
+  background: var(--color-border);
+}
+
+.join-game-btn.cancel:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
+
+.difficulty-btn.hard:hover:enabled {
+  background: var(--color-danger, #dc3545);
+  color: white;
+}
+
+.difficulty-btn:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}

src/app/pages/welcome/welcome.component.html

@@ -1,25 +1,97 @@
 <main class="welcome-shell">
+  <div class="theme-toggle-container">
+    <div class="switch">
+      <input type="checkbox" class="switch__input" id="themeToggle" (change)="toggleDarkMode()" [checked]="!isDarkMode()">
+      <label class="switch__label" for="themeToggle">
+        <span class="switch__indicator"></span>
+        <span class="switch__decoration"></span>
+      </label>
+    </div>
+  </div>
+  <div class="clouds-container">
+    <div class="cloud cloud-left">
+      <img src="arabian-chess/player-one.gif" alt="Player One" class="cloud-gif" />
+    </div>
+    <div class="plane plane-left">
+      <img src="arabian-chess/plane.png" alt="Plane" class="plane-body" />
+      <img src="arabian-chess/raf.gif" alt="Raf" class="plane-gif" />
+    </div>
+    <div class="cloud cloud-right">
+      <div class="gif-with-halo">
+        <img src="arabian-chess/player-two.gif" alt="Player Two" class="cloud-gif" />
+      </div>
+    </div>
+  </div>
   <section class="welcome-card">
     <h1>Welcome to NowChess</h1>
     <p>Pick a mode to begin.</p>
 
     <div class="mode-grid">
-      <button type="button" class="mode mode-disabled" disabled>
+      <button type="button" class="mode mode-active" (click)="toggleDifficultySelector()" [disabled]="creating">
         <span>Bot</span>
-        <small>Coming soon</small>
+        <small>{{ creating ? 'Creating game...' : 'Choose difficulty' }}</small>
       </button>
 
+      @if (showDifficultySelector) {
+        <div class="difficulty-selector">
+          <p>Select difficulty:</p>
+          <div class="difficulty-buttons">
+            <button type="button" class="difficulty-btn easy" (click)="startVsBot('easy')" [disabled]="creating">
+              Easy
+            </button>
+            <button type="button" class="difficulty-btn medium" (click)="startVsBot('medium')" [disabled]="creating">
+              Medium
+            </button>
+            <button type="button" class="difficulty-btn hard" (click)="startVsBot('hard')" [disabled]="creating">
+              Hard
+            </button>
+          </div>
+        </div>
+      }
+
       <button type="button" class="mode mode-active" (click)="startOneVsOne()" [disabled]="creating">
         <span>1 vs 1</span>
         <small>{{ creating ? 'Creating game...' : 'Start now' }}</small>
       </button>
 
-      <button type="button" class="mode mode-disabled" disabled>
+      <button type="button" class="mode mode-active" (click)="toggleJoinGameForm()" [disabled]="joiningGame">
-        <span>Future Technique</span>
+        <span>Join Game</span>
-        <small>Placeholder</small>
+        <small>{{ joiningGame ? 'Joining...' : 'Enter game ID' }}</small>
       </button>
     </div>
 
+    @if (showJoinGameForm) {
+      <div class="join-game-form">
+        <p>Enter the game ID:</p>
+        <div class="join-game-input-group">
+          <input
+            type="text"
+            class="join-game-input"
+            [(ngModel)]="gameIdInput"
+            placeholder="Paste game ID here"
+            [disabled]="joiningGame"
+            (keyup.enter)="joinGame()"
+          />
+          <button
+            type="button"
+            class="join-game-btn join"
+            (click)="joinGame()"
+            [disabled]="joiningGame || !gameIdInput.trim()"
+          >
+            {{ joiningGame ? 'Joining...' : 'Join' }}
+          </button>
+          <button
+            type="button"
+            class="join-game-btn cancel"
+            (click)="clearJoinGameForm()"
+            [disabled]="joiningGame"
+          >
+            Cancel
+          </button>
+        </div>
+      </div>
+    }
+
     @if (errorMessage) {
       <p class="error">{{ errorMessage }}</p>
     }

src/app/pages/welcome/welcome.component.ts

@@ -1,5 +1,6 @@
 import { CommonModule } from '@angular/common';
 import { Component } from '@angular/core';
+import { FormsModule } from '@angular/forms';
 import { Router } from '@angular/router';
 import { finalize } from 'rxjs';
 import { getErrorMessage } from '../../core/http/error-message.util';
@@ -8,18 +9,31 @@ import { GameApiService } from '../../services/game-api.service';
 @Component({
   selector: 'app-welcome',
   standalone: true,
-  imports: [CommonModule],
+  imports: [CommonModule, FormsModule],
   templateUrl: './welcome.component.html',
   styleUrl: './welcome.component.css'
 })
 export class WelcomeComponent {
   creating = false;
   errorMessage = '';
+  showDifficultySelector = false;
+  showJoinGameForm = false;
+  gameIdInput = '';
+  joiningGame = false;
 
   constructor(
     private readonly router: Router,
     private readonly gameApi: GameApiService
-  ) {}
+  ) {
+    this.initTheme();
+  }
+
+  private initTheme(): void {
+    const savedTheme = localStorage.getItem('theme');
+    if (savedTheme === 'dark') {
+      document.documentElement.setAttribute('data-theme', 'dark');
+    }
+  }
 
   startOneVsOne(): void {
     if (this.creating) {
@@ -41,4 +55,83 @@ export class WelcomeComponent {
         }
       });
   }
+
+  startVsBot(difficulty: 'easy' | 'medium' | 'hard'): void {
+    if (this.creating) {
+      return;
+    }
+
+    this.errorMessage = '';
+    this.creating = true;
+    this.showDifficultySelector = false;
+
+    this.gameApi
+      .createGameVsBot(difficulty)
+      .pipe(finalize(() => (this.creating = false)))
+      .subscribe({
+        next: (game) => {
+          void this.router.navigate(['/game', game.gameId]);
+        },
+        error: (error) => {
+          this.errorMessage = getErrorMessage(error, 'Unable to create a game against bot.');
+        }
+      });
+  }
+
+  toggleDifficultySelector(): void {
+    this.showDifficultySelector = !this.showDifficultySelector;
+    this.showJoinGameForm = false;
+    this.errorMessage = '';
+  }
+
+  toggleJoinGameForm(): void {
+    this.showJoinGameForm = !this.showJoinGameForm;
+    this.showDifficultySelector = false;
+    this.errorMessage = '';
+    this.gameIdInput = '';
+  }
+
+  joinGame(): void {
+    if (this.joiningGame || !this.gameIdInput.trim()) {
+      return;
+    }
+
+    this.errorMessage = '';
+    this.joiningGame = true;
+
+    this.gameApi
+      .getGame(this.gameIdInput.trim())
+      .pipe(finalize(() => (this.joiningGame = false)))
+      .subscribe({
+        next: (game) => {
+          void this.router.navigate(['/game', game.gameId]);
+        },
+        error: (error) => {
+          this.errorMessage = getErrorMessage(error, 'Unable to find or join the game.');
+        }
+      });
+  }
+
+  clearJoinGameForm(): void {
+    this.showJoinGameForm = false;
+    this.gameIdInput = '';
+    this.errorMessage = '';
+  }
+
+  toggleDarkMode(): void {
+    const htmlElement = document.documentElement;
+    const isDarkMode = htmlElement.getAttribute('data-theme') === 'dark';
+    
+    if (isDarkMode) {
+      htmlElement.removeAttribute('data-theme');
+      localStorage.removeItem('theme');
+    } else {
+      htmlElement.setAttribute('data-theme', 'dark');
+      localStorage.setItem('theme', 'dark');
+    }
+  }
+
+  isDarkMode(): boolean {
+    return document.documentElement.getAttribute('data-theme') === 'dark';
+  }
 }

src/app/services/board-selection.service.ts

@@ -0,0 +1,64 @@
+import { Injectable, DestroyRef, inject } from '@angular/core';
+import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
+import { GameApiService } from './game-api.service';
+import { getPieceAtSquare, isPieceColor } from '../core/chess/fen.utils';
+import { GameState, LegalMove } from '../models/game.models';
+
+export interface BoardSelection {
+  selectedSquare: string | null;
+  highlightedSquares: string[];
+  selectedSquareMoves: LegalMove[];
+}
+
+@Injectable({ providedIn: 'root' })
+export class BoardSelectionService {
+  private readonly gameApi = inject(GameApiService);
+  private readonly destroyRef = inject(DestroyRef);
+
+  handleSquareSelection(
+    square: string,
+    gameId: string,
+    state: GameState | null,
+    currentSelection: BoardSelection,
+    onMovesLoaded: (moves: LegalMove[]) => void,
+    onError: (error: string) => void
+  ): BoardSelection {
+    if (!state) {
+      return currentSelection;
+    }
+
+    // If clicking on a highlighted square, it's a move
+    if (currentSelection.selectedSquare && currentSelection.highlightedSquares.includes(square)) {
+      const selectedMove = currentSelection.selectedSquareMoves.find((move) => move.to === square);
+      if (selectedMove) {
+        return { selectedSquare: null, highlightedSquares: [], selectedSquareMoves: [] };
+      }
+      return currentSelection;
+    }
+
+    // Check if square has a piece of the correct color
+    const piece = getPieceAtSquare(state.fen, square);
+    if (!piece || !isPieceColor(piece, state.turn)) {
+      return { selectedSquare: null, highlightedSquares: [], selectedSquareMoves: [] };
+    }
+
+    // Load legal moves for this square
+    this.gameApi
+      .getLegalMoves(gameId, square)
+      .pipe(takeUntilDestroyed(this.destroyRef))
+      .subscribe({
+        next: (response) => {
+          onMovesLoaded(response.moves);
+        },
+        error: () => {
+          onError('Could not load legal moves for selected square.');
+        }
+      });
+
+    return { selectedSquare: square, highlightedSquares: [], selectedSquareMoves: [] };
+  }
+
+  clearSelection(): BoardSelection {
+    return { selectedSquare: null, highlightedSquares: [], selectedSquareMoves: [] };
+  }
+}

src/app/services/bot-move.service.ts

@@ -0,0 +1,78 @@
+import { Injectable, DestroyRef, inject } from '@angular/core';
+import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
+import { delay, Subscription } from 'rxjs';
+import { GameApiService } from './game-api.service';
+import { getErrorMessage } from '../core/http/error-message.util';
+import { GameFull, GameState } from '../models/game.models';
+
+@Injectable({ providedIn: 'root' })
+export class BotMoveService {
+  private readonly gameApi = inject(GameApiService);
+  private readonly destroyRef = inject(DestroyRef);
+  private botMoveSubscription: Subscription | null = null;
+
+  private isBotPlayer(playerId: string): boolean {
+    return playerId.startsWith('bot-');
+  }
+
+  isPlayingAgainstBot(game: GameFull | null): boolean {
+    if (!game) {
+      return false;
+    }
+    return this.isBotPlayer(game.white.id) || this.isBotPlayer(game.black.id);
+  }
+
+  isCurrentPlayerBot(game: GameFull | null, state: GameState | null): boolean {
+    if (!game || !state) {
+      return false;
+    }
+    const currentPlayer = state.turn === 'white' ? game.white : game.black;
+    return this.isBotPlayer(currentPlayer.id);
+  }
+
+  tryMakeBotMove(
+    gameId: string,
+    game: GameFull | null,
+    state: GameState | null,
+    onSuccess: (updatedState: GameState) => void,
+    onError: (error: string) => void
+  ): void {
+    if (!this.isPlayingAgainstBot(game) || !this.isCurrentPlayerBot(game, state) || !state) {
+      return;
+    }
+
+    this.botMoveSubscription?.unsubscribe();
+    this.botMoveSubscription = this.gameApi
+      .getLegalMoves(gameId)
+      .pipe(
+        delay(1000),
+        takeUntilDestroyed(this.destroyRef)
+      )
+      .subscribe({
+        next: (response) => {
+          if (response.moves.length === 0) {
+            return;
+          }
+          const botMove = response.moves[Math.floor(Math.random() * response.moves.length)];
+          this.gameApi
+            .makeMove(gameId, botMove.uci)
+            .pipe(takeUntilDestroyed(this.destroyRef))
+            .subscribe({
+              next: (updatedState) => {
+                onSuccess(updatedState);
+              },
+              error: (error) => {
+                onError(getErrorMessage(error, 'Bot move failed.'));
+              }
+            });
+        },
+        error: () => {
+          onError('Could not get legal moves for bot move.');
+        }
+      });
+  }
+
+  cleanup(): void {
+    this.botMoveSubscription?.unsubscribe();
+  }
+}

src/app/services/game-api.service.ts

@@ -1,32 +1,54 @@
-import { Injectable } from '@angular/core';
+import { Injectable, inject } from '@angular/core';
 import { HttpClient, HttpParams } from '@angular/common/http';
 import { Observable } from 'rxjs';
 import { environment } from '../../environments/environment';
 import {
-  ErrorEvent,
   GameFull,
   GameState,
   GameStreamEvent,
-  LegalMovesResponse
+  LegalMovesResponse,
+  PlayerInfo
 } from '../models/game.models';
+import { StreamHandlerService } from './stream-handler.service';
 
 @Injectable({ providedIn: 'root' })
 export class GameApiService {
   private readonly apiBase = environment.apiBaseUrl;
   private readonly wsBase = environment.wsBaseUrl;
+  private readonly apiPath = environment.apiPath;
+  private readonly streamHandler = inject(StreamHandlerService);
 
   constructor(private readonly http: HttpClient) {}
 
   createGame(): Observable<GameFull> {
-    return this.http.post<GameFull>(`${this.apiBase}/api/board/game`, {});
+    return this.http.post<GameFull>(`${this.apiBase}${this.apiPath}`, {});
+  }
+
+  createGameVsBot(difficulty: 'easy' | 'medium' | 'hard' = 'medium'): Observable<GameFull> {
+    const playerColor = Math.random() > 0.5 ? 'white' : 'black';
+    const playerInfo: PlayerInfo = {
+      id: `player-${Date.now()}`,
+      displayName: 'You'
+    };
+    const botInfo: PlayerInfo = {
+      id: `bot-${difficulty}`,
+      displayName: `Bot (${difficulty})`
+    };
+
+    const payload =
+      playerColor === 'white'
+        ? { white: playerInfo, black: botInfo }
+        : { white: botInfo, black: playerInfo };
+
+    return this.http.post<GameFull>(`${this.apiBase}${this.apiPath}`, payload);
   }
 
   getGame(gameId: string): Observable<GameFull> {
-    return this.http.get<GameFull>(`${this.apiBase}/api/board/game/${gameId}`);
+    return this.http.get<GameFull>(`${this.apiBase}${this.apiPath}/${gameId}`);
   }
 
   makeMove(gameId: string, uci: string): Observable<GameState> {
-    return this.http.post<GameState>(`${this.apiBase}/api/board/game/${gameId}/move/${uci}`, {});
+    return this.http.post<GameState>(`${this.apiBase}${this.apiPath}/${gameId}/move/${uci}`, {});
   }
 
   getLegalMoves(gameId: string, square?: string): Observable<LegalMovesResponse> {
@@ -34,127 +56,29 @@ export class GameApiService {
     if (square) {
       params = params.set('square', square);
     }
-    return this.http.get<LegalMovesResponse>(`${this.apiBase}/api/board/game/${gameId}/moves`, { params });
+    return this.http.get<LegalMovesResponse>(`${this.apiBase}${this.apiPath}/${gameId}/moves`, { params });
   }
 
   importFen(fen: string): Observable<GameFull> {
-    return this.http.post<GameFull>(`${this.apiBase}/api/board/game/import/fen`, { fen });
+    return this.http.post<GameFull>(`${this.apiBase}${this.apiPath}/import/fen`, { fen });
   }
 
   importPgn(pgn: string): Observable<GameFull> {
-    return this.http.post<GameFull>(`${this.apiBase}/api/board/game/import/pgn`, { pgn });
+    return this.http.post<GameFull>(`${this.apiBase}${this.apiPath}/import/pgn`, { pgn });
+  }
+
+  private resolveWsBase(): string {
+    if (this.wsBase) {
+      return this.wsBase;
+    }
+
+    const wsProtocol = window.location.protocol === 'https:' ? 'wss' : 'ws';
+    return `${wsProtocol}://${window.location.host}`;
   }
 
   streamGame(gameId: string): Observable<GameStreamEvent> {
-    return new Observable<GameStreamEvent>((observer) => {
+    const wsUrl = `${this.resolveWsBase()}${this.apiPath}/${gameId}/stream`;
-      const wsUrl = `${this.wsBase}/api/board/game/${gameId}/stream`;
+    const fallbackUrl = `${this.apiBase}${this.apiPath}/${gameId}/stream`;
-      const streamUrl = `${this.apiBase}/api/board/game/${gameId}/stream`;
+    return this.streamHandler.createGameStream(wsUrl, fallbackUrl, gameId);
-      const ws = new WebSocket(wsUrl);
-      const abortController = new AbortController();
-      let connected = false;
-      let fallbackActive = false;
-
-      const parseEvent = (raw: string): GameStreamEvent | null => {
-        if (!raw.trim()) {
-          return null;
-        }
-
-        try {
-          const parsed = JSON.parse(raw) as GameStreamEvent;
-          return parsed;
-        } catch {
-          return null;
-        }
-      };
-
-      const emitErrorEvent = (message: string): void => {
-        const errorEvent: ErrorEvent = {
-          type: 'error',
-          error: { code: 'STREAM_ERROR', message }
-        };
-        observer.next(errorEvent);
-      };
-
-      const startNdjsonFallback = async (): Promise<void> => {
-        if (fallbackActive) {
-          return;
-        }
-
-        fallbackActive = true;
-
-        try {
-          const response = await fetch(streamUrl, {
-            headers: { Accept: 'application/x-ndjson' },
-            signal: abortController.signal
-          });
-
-          if (!response.ok || !response.body) {
-            emitErrorEvent(`Unable to open stream: HTTP ${response.status}`);
-            observer.complete();
-            return;
-          }
-
-          const reader = response.body.getReader();
-          const decoder = new TextDecoder();
-          let buffer = '';
-
-          while (true) {
-            const { value, done } = await reader.read();
-            if (done) {
-              break;
-            }
-
-            buffer += decoder.decode(value, { stream: true });
-            const lines = buffer.split('\n');
-            buffer = lines.pop() ?? '';
-
-            for (const line of lines) {
-              const event = parseEvent(line);
-              if (event) {
-                observer.next(event);
-              }
-            }
-          }
-
-          observer.complete();
-        } catch (error) {
-          if ((error as Error).name !== 'AbortError') {
-            emitErrorEvent((error as Error).message);
-            observer.error(error);
-          }
-        }
-      };
-
-      ws.onopen = () => {
-        connected = true;
-      };
-
-      ws.onmessage = (message) => {
-        const payload = typeof message.data === 'string' ? message.data : '';
-        const event = parseEvent(payload);
-        if (event) {
-          observer.next(event);
-        }
-      };
-
-      ws.onerror = () => {
-        if (!connected) {
-          void startNdjsonFallback();
-        }
-      };
-
-      ws.onclose = () => {
-        if (!connected) {
-          void startNdjsonFallback();
-        } else {
-          observer.complete();
-        }
-      };
-
-      return () => {
-        abortController.abort();
-        ws.close();
-      };
-    });
   }
 }

src/app/services/game-completion.service.ts

@@ -0,0 +1,46 @@
+import { Injectable } from '@angular/core';
+import { GameFull, GameState, GameStatus } from '../models/game.models';
+
+export interface GameCompletion {
+  isFinished: boolean;
+  message: string;
+}
+
+@Injectable({ providedIn: 'root' })
+export class GameCompletionService {
+  getGameCompletion(game: GameFull | null, state: GameState | null): GameCompletion {
+    if (!game || !state) {
+      return { isFinished: false, message: '' };
+    }
+
+    const status = state.status;
+    const gameEndingStatuses: GameStatus[] = ['checkmate', 'stalemate', 'resign', 'draw', 'insufficientMaterial'];
+
+    if (!gameEndingStatuses.includes(status)) {
+      return { isFinished: false, message: '' };
+    }
+
+    const message = this.buildCompletionMessage(status, state, game);
+    return { isFinished: true, message };
+  }
+
+  private buildCompletionMessage(status: GameStatus, state: GameState, game: GameFull): string {
+    switch (status) {
+      case 'checkmate':
+        const winner = state.winner === 'white' ? game.white.displayName : game.black.displayName;
+        return `Checkmate! ${winner} wins!`;
+      case 'stalemate':
+        return 'Stalemate! The game is a draw.';
+      case 'resign':
+        const resignedPlayer = state.winner === 'white' ? game.black.displayName : game.white.displayName;
+        const resignedWinner = state.winner === 'white' ? game.white.displayName : game.black.displayName;
+        return `${resignedPlayer} resigned. ${resignedWinner} wins!`;
+      case 'draw':
+        return 'Draw! The game ended in a draw.';
+      case 'insufficientMaterial':
+        return 'Insufficient material! The game is a draw.';
+      default:
+        return 'Game ended!';
+    }
+  }
+}

src/app/services/game-import.service.ts

@@ -0,0 +1,62 @@
+import { Injectable, DestroyRef, inject } from '@angular/core';
+import { Router } from '@angular/router';
+import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
+import { GameApiService } from './game-api.service';
+import { getErrorMessage } from '../core/http/error-message.util';
+
+@Injectable({ providedIn: 'root' })
+export class GameImportService {
+  private readonly gameApi = inject(GameApiService);
+  private readonly router = inject(Router);
+  private readonly destroyRef = inject(DestroyRef);
+
+  importFen(
+    fen: string,
+    onSuccess: () => void,
+    onError: (error: string) => void
+  ): void {
+    const trimmedFen = fen.trim();
+    if (!trimmedFen) {
+      onError('Please provide a FEN string.');
+      return;
+    }
+
+    this.gameApi
+      .importFen(trimmedFen)
+      .pipe(takeUntilDestroyed(this.destroyRef))
+      .subscribe({
+        next: (game) => {
+          onSuccess();
+          void this.router.navigate(['/game', game.gameId]);
+        },
+        error: (error) => {
+          onError(getErrorMessage(error, 'FEN import failed.'));
+        }
+      });
+  }
+
+  importPgn(
+    pgn: string,
+    onSuccess: () => void,
+    onError: (error: string) => void
+  ): void {
+    const trimmedPgn = pgn.trim();
+    if (!trimmedPgn) {
+      onError('Please provide a PGN string.');
+      return;
+    }
+
+    this.gameApi
+      .importPgn(trimmedPgn)
+      .pipe(takeUntilDestroyed(this.destroyRef))
+      .subscribe({
+        next: (game) => {
+          onSuccess();
+          void this.router.navigate(['/game', game.gameId]);
+        },
+        error: (error) => {
+          onError(getErrorMessage(error, 'PGN import failed.'));
+        }
+      });
+  }
+}

src/app/services/game-stream.service.ts

@@ -0,0 +1,63 @@
+import { Injectable, DestroyRef, inject } from '@angular/core';
+import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
+import { interval, startWith, Subscription, switchMap } from 'rxjs';
+import { GameApiService } from './game-api.service';
+import { GameStreamEvent } from '../models/game.models';
+
+@Injectable({ providedIn: 'root' })
+export class GameStreamService {
+  private readonly gameApi = inject(GameApiService);
+  private readonly destroyRef = inject(DestroyRef);
+  private streamSubscription: Subscription | null = null;
+  private pollSubscription: Subscription | null = null;
+
+  startStreaming(
+    gameId: string,
+    onEvent: (event: GameStreamEvent) => void,
+    onStreamError: () => void
+  ): void {
+    this.streamSubscription = this.gameApi
+      .streamGame(gameId)
+      .pipe(takeUntilDestroyed(this.destroyRef))
+      .subscribe({
+        next: (event) => onEvent(event),
+        error: () => {
+          onStreamError();
+          this.startPolling(gameId, onEvent);
+        },
+        complete: () => {
+          onStreamError();
+          this.startPolling(gameId, onEvent);
+        }
+      });
+  }
+
+  startPolling(gameId: string, onEvent: (event: GameStreamEvent) => void): void {
+    if (this.pollSubscription) {
+      return;
+    }
+
+    this.pollSubscription = interval(1500)
+      .pipe(
+        startWith(0),
+        switchMap(() => this.gameApi.getGame(gameId)),
+        takeUntilDestroyed(this.destroyRef)
+      )
+      .subscribe({
+        next: (game) => {
+          const event: GameStreamEvent = {
+            type: 'gameFull',
+            game
+          };
+          onEvent(event);
+        }
+      });
+  }
+
+  cleanup(): void {
+    this.streamSubscription?.unsubscribe();
+    this.pollSubscription?.unsubscribe();
+    this.streamSubscription = null;
+    this.pollSubscription = null;
+  }
+}

src/app/services/stream-handler.service.ts

@@ -0,0 +1,122 @@
+import { Injectable } from '@angular/core';
+import { Observable } from 'rxjs';
+import { GameStreamEvent, ErrorEvent } from '../models/game.models';
+
+@Injectable({ providedIn: 'root' })
+export class StreamHandlerService {
+  createGameStream(wsUrl: string, fallbackUrl: string, gameId: string): Observable<GameStreamEvent> {
+    return new Observable<GameStreamEvent>((observer) => {
+      const ws = new WebSocket(wsUrl);
+      const abortController = new AbortController();
+      let connected = false;
+      let fallbackActive = false;
+
+      const parseEvent = (raw: string): GameStreamEvent | null => {
+        if (!raw.trim()) {
+          return null;
+        }
+
+        try {
+          return JSON.parse(raw) as GameStreamEvent;
+        } catch {
+          return null;
+        }
+      };
+
+      const emitErrorEvent = (message: string): void => {
+        const errorEvent: ErrorEvent = {
+          type: 'error',
+          error: { code: 'STREAM_ERROR', message }
+        };
+        observer.next(errorEvent);
+      };
+
+      const startNdjsonFallback = async (): Promise<void> => {
+        if (fallbackActive) {
+          return;
+        }
+
+        fallbackActive = true;
+        console.log(`[StreamHandler] NDJSON fallback started for ${gameId}, URL:`, fallbackUrl);
+
+        try {
+          const response = await fetch(fallbackUrl, {
+            headers: { Accept: 'application/x-ndjson' },
+            signal: abortController.signal
+          });
+
+          if (!response.ok || !response.body) {
+            console.error(`[StreamHandler] NDJSON fetch failed: HTTP ${response.status}`);
+            emitErrorEvent(`Unable to open stream: HTTP ${response.status}`);
+            observer.complete();
+            return;
+          }
+
+          console.log(`[StreamHandler] NDJSON stream connected for ${gameId}`);
+          const reader = response.body.getReader();
+          const decoder = new TextDecoder();
+          let buffer = '';
+
+          while (true) {
+            const { value, done } = await reader.read();
+            if (done) {
+              break;
+            }
+
+            buffer += decoder.decode(value, { stream: true });
+            const lines = buffer.split('\n');
+            buffer = lines.pop() ?? '';
+
+            for (const line of lines) {
+              const event = parseEvent(line);
+              if (event) {
+                observer.next(event);
+              }
+            }
+          }
+
+          observer.complete();
+        } catch (error) {
+          if ((error as Error).name !== 'AbortError') {
+            emitErrorEvent((error as Error).message);
+            observer.error(error);
+          }
+        }
+      };
+
+      ws.onopen = () => {
+        connected = true;
+      };
+
+      ws.onmessage = (message) => {
+        const payload = typeof message.data === 'string' ? message.data : '';
+        const event = parseEvent(payload);
+        if (event) {
+          observer.next(event);
+        }
+      };
+
+      ws.onerror = (error) => {
+        console.warn(`[StreamHandler] WebSocket error for ${gameId}, attempting NDJSON fallback:`, error);
+        if (!connected) {
+          void startNdjsonFallback();
+        }
+      };
+
+      ws.onclose = () => {
+        console.warn(`[StreamHandler] WebSocket closed for ${gameId}, connected=${connected}`);
+        if (!connected) {
+          console.log(`[StreamHandler] Starting NDJSON fallback for ${gameId}`);
+          void startNdjsonFallback();
+        } else {
+          observer.complete();
+        }
+      };
+
+      return () => {
+        abortController.abort();
+        ws.close();
+      };
+    });
+  }
+}

src/environments/environment.development.ts

@@ -1,5 +1,6 @@
 export const environment = {
   production: false,
-  apiBaseUrl: 'http://localhost:8080',
+  apiBaseUrl: '',
-  wsBaseUrl: 'ws://localhost:8080'
+  wsBaseUrl: 'ws://localhost:8080',
+  apiPath: '/api/board/game'
 };

src/environments/environment.ts

@@ -1,5 +1,6 @@
 export const environment = {
   production: true,
-  apiBaseUrl: 'http://localhost:8080',
+  apiBaseUrl: '',
-  wsBaseUrl: 'ws://localhost:8080'
+  wsBaseUrl: 'ws://localhost:8080',
+  apiPath: '/api/board/game'
 };

src/styles-variables.css

@@ -0,0 +1,125 @@
+/* ========================================
+   COLOR VARIABLES - Semantic Naming
+   ======================================== */
+
+/* Light Mode Colors (Default) */
+:root:not([data-theme='dark']) {
+  /* Primary Colors - Light Mode */
+  --color-primary: #BA6D4B;
+  --color-primary-dark: #5A2C28;
+  --color-primary-light: #F3C8A0;
+
+  /* Secondary Colors - Light Mode */
+  --color-secondary-mint: #B9DAD1;
+  --color-secondary-blue: #B9C2DA;
+  --color-secondary-purple: #C19EF5;
+  --color-secondary-lime: #E1EAA9;
+
+  /* Functional Colors - Light Mode */
+  --color-bg-main: #F3C8A0;
+  --color-bg-board: #B9DAD1;
+  --color-bg-card: #E1EAA9;
+  --color-bg-input: #B9DAD1;
+  --color-bg-input-focus: #B9C2DA;
+  --color-bg-button: #C19EF5;
+  --color-bg-button-hover: #BA6D4B;
+
+  --color-text-primary: #5A2C28;
+  --color-text-button-hover: #F3C8A0;
+  --color-border: #5A2C28;
+}
+
+/* Dark Mode Colors */
+:root[data-theme='dark'] {
+  /* Primary Colors - Dark Mode */
+  --color-primary: #1a3a52;
+  --color-primary-dark: #0f1f2e;
+  --color-primary-light: #2d5a7b;
+
+  /* Secondary Colors - Dark Mode */
+  --color-secondary-mint: #4a7c7c;
+  --color-secondary-blue: #5a6fa5;
+  --color-secondary-purple: #7d5fa8;
+  --color-secondary-lime: #6b8e23;
+
+  /* Functional Colors - Dark Mode */
+  --color-bg-main: #1a2f47;
+  --color-bg-board: #2d5a7b;
+  --color-bg-card: #3d4e63;
+  --color-bg-input: #2d4a6f;
+  --color-bg-input-focus: #3d5a8f;
+  --color-bg-button: #5a7da5;
+  --color-bg-button-hover: #7a9dc5;
+
+  --color-text-primary: #e8f0f8;
+  --color-text-button-hover: #ffffff;
+  --color-border: #4a7c9c;
+}
+
+:root {
+
+  /* ========================================
+     TYPOGRAPHY SIZES
+     ======================================== */
+
+  /* Header Sizes */
+  --heading-h1: clamp(1.5rem, 4vw, 2rem);
+  --heading-h1-tablet: clamp(1.25rem, 3vw, 1.75rem);
+  --heading-h1-mobile: 1.25rem;
+  --heading-h1-small: 1.1rem;
+
+  --heading-h2: clamp(1.5rem, 4vw, 2rem);
+
+  /* ========================================
+     SPACING SIZES (XS, SM, MD, LG, XL)
+     ======================================== */
+
+  /* Extra Small - Minimal spacing */
+  --size-xs: 0.25rem;
+  --size-xs-padding: 0.4rem;
+  --size-xs-gap: 0.15rem;
+
+  /* Small - Compact spacing */
+  --size-sm: 0.5rem;
+  --size-sm-padding: 0.5rem;
+  --size-sm-gap: 0.35rem;
+
+  /* Medium - Default spacing */
+  --size-md: 0.75rem;
+  --size-md-padding: 0.6rem 0.75rem;
+  --size-md-gap: 0.5rem;
+
+  /* Large - Generous spacing */
+  --size-lg: 1rem;
+  --size-lg-padding: 1rem;
+  --size-lg-gap: 0.75rem;
+
+  /* Extra Large - Maximum spacing */
+  --size-xl: 1.5rem;
+  --size-xl-padding: 1.5rem;
+  --size-xl-gap: 1rem;
+
+  /* ========================================
+     BORDER & RADIUS
+     ======================================== */
+  --border-width: 2px;
+  --border-radius-sm: 8px;
+  --border-radius-md: 10px;
+  --border-radius-lg: 12px;
+
+  /* ========================================
+     FORM ELEMENTS
+     ======================================== */
+  --form-input-padding: 0.6rem 0.75rem;
+  --form-input-border: var(--border-width) solid var(--color-border);
+  --form-input-radius: var(--border-radius-md);
+
+  --button-padding: 0.6rem 1rem;
+  --button-border: var(--border-width) solid var(--color-border);
+  --button-radius: var(--border-radius-sm);
+
+  /* ========================================
+     SHADOWS
+     ======================================== */
+  --shadow-md: 0 8px 24px rgba(90, 44, 40, 0.2);
+}

src/styles.css

@@ -1,26 +1,61 @@
+@import 'styles-variables.css';
 @import 'bootstrap/dist/css/bootstrap.min.css';
 
-:root {
-  --warm-primary: #BA6D4B;
-  --warm-dark: #5A2C28;
-  --warm-light: #F3C8A0;
-  --cool-mint: #B9DAD1;
-  --cool-blue: #B9C2DA;
-  --cool-purple: #C19EF5;
-  --cool-lime: #E1EAA9;
-}
-
 * {
   box-sizing: border-box;
 }
 
+/* Light Mode (Default) */
+html:not([data-theme='dark']),
+html:not([data-theme='dark']) body {
+  background: linear-gradient(160deg, var(--color-primary-light), var(--color-secondary-mint));
+  color: var(--color-text-primary);
+}
+
+html:not([data-theme='dark']) body::before {
+  display: none;
+}
+
+/* Dark Mode */
+html[data-theme='dark'],
+html[data-theme='dark'] body {
+  background: #0f1f2e;
+  background-image: 
+    radial-gradient(2px 2px at 20px 30px, rgba(255, 255, 255, 0.8), rgba(255, 255, 255, 0)),
+    radial-gradient(2px 2px at 60px 70px, rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0)),
+    radial-gradient(1px 1px at 50px 50px, rgba(255, 255, 255, 0.7), rgba(255, 255, 255, 0)),
+    radial-gradient(1px 1px at 130px 80px, rgba(255, 255, 255, 0.8), rgba(255, 255, 255, 0)),
+    radial-gradient(2px 2px at 90px 10px, rgba(255, 255, 255, 0.6), rgba(255, 255, 255, 0)),
+    radial-gradient(1px 1px at 130px 120px, rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0)),
+    radial-gradient(2px 2px at 10px 90px, rgba(255, 255, 255, 0.7), rgba(255, 255, 255, 0)),
+    radial-gradient(1px 1px at 40px 120px, rgba(255, 255, 255, 0.8), rgba(255, 255, 255, 0));
+  background-repeat: repeat;
+  background-size: 150px 150px;
+  background-attachment: fixed;
+  color: var(--color-text-primary);
+}
+
+html[data-theme='dark'] body::before {
+  content: '';
+  position: fixed;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  background: 
+    radial-gradient(circle at 20% 80%, rgba(45, 90, 123, 0.1) 0%, transparent 50%),
+    radial-gradient(circle at 80% 20%, rgba(90, 111, 165, 0.1) 0%, transparent 50%),
+    radial-gradient(circle at 50% 50%, rgba(29, 53, 82, 0.05) 0%, transparent 50%);
+  pointer-events: none;
+  z-index: -1;
+}
+
 html,
 body {
   margin: 0;
   min-height: 100%;
   font-family: "Comic Sans MS", "Comic Sans", cursive;
-  background: linear-gradient(160deg, var(--warm-light), var(--cool-mint));
+  position: relative;
-  color: var(--warm-dark);
 }
 
 button,