body {
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #e0f7fa;
    color: #333;
    overflow-x: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Dark Mode Styles */
body.dark-mode {
    background-color: #1a1a1a;
    color: #e0e0e0;
}

body.dark-mode .game-area {
    background-color: #2d2d2d;
    border: 2px solid #4a4a4a;
}

body.dark-mode .header h1 {
    color: #4db6ac;
}

body.dark-mode .header .subtitle {
    color: #b0bec5;
}

body.dark-mode .instructions {
    background: linear-gradient(135deg, #2e3b2e, #3a4a3a);
    border-color: #4db6ac;
}

body.dark-mode .instructions h3,
body.dark-mode .instructions p {
    color: #4db6ac;
}

body.dark-mode .puzzle-piece {
    background-color: #3a3a3a;
    border-color: #4db6ac;
    color: #e0e0e0;
}

body.dark-mode .puzzle-piece.selected {
    background-color: #4db6ac;
    color: #1a1a1a;
}

body.dark-mode .controls button {
    background-color: #4db6ac;
    color: #1a1a1a;
}

body.dark-mode .controls button:hover {
    background-color: #26a69a;
}

body.dark-mode .controls button:disabled {
    background-color: #4a4a4a;
    color: #888;
}

body.dark-mode .difficulty-selector label,
body.dark-mode .puzzle-topic-selector label,
body.dark-mode .affirmation-theme-selector label,
body.dark-mode .music-selector label {
    color: #4db6ac;
}

body.dark-mode .difficulty-selector select,
body.dark-mode .puzzle-topic-selector select,
body.dark-mode .affirmation-theme-selector select,
body.dark-mode .music-selector select {
    background-color: #3a3a3a;
    border-color: #4db6ac;
    color: #e0e0e0;
}

body.dark-mode .resources-link a {
    color: #4db6ac;
}

body.dark-mode .resources-link a:hover {
    color: #26a69a;
}

body.dark-mode .privacy-statement {
    background-color: #2d2d2d;
    border-color: #4a4a4a;
    color: #b0bec5;
}

body.dark-mode #message {
    background-color: #2d2d2d;
    border-color: #4db6ac;
    color: #e0e0e0;
}

.header {
    margin-bottom: 10px;
    color: #00796b;
}

.header h1 {
    font-size: 2.5em;
    margin: 0;
    text-align: center;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.game-area {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    padding: 20px;
    background-color: #ffffff;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    max-width: 90%;
    box-sizing: border-box;
}

/* Instructions */
.instructions {
    background: linear-gradient(135deg, #e8f5e8, #f0f8f0);
    border: 2px solid #00796b;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    text-align: center;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.instructions h3 {
    margin-top: 0;
    color: #00796b;
    font-size: 1.3em;
}

.instructions p {
    margin: 10px 0;
    color: #00796b;
    line-height: 1.4;
    font-size: 0.95em;
}

.hide-btn {
    background-color: #00796b;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9em;
    margin-top: 10px;
    transition: background-color 0.3s ease;
}

.hide-btn:hover {
    background-color: #005252;
}

.instructions.hidden {
    display: none;
}

.difficulty-selector {
    margin-bottom: 20px;
    text-align: center;
}

.difficulty-selector label {
    font-weight: bold;
    margin-right: 10px;
    color: #00796b;
}

.difficulty-selector select {
    padding: 8px 15px;
    font-size: 1em;
    border: 2px solid #00796b;
    border-radius: 6px;
    background-color: white;
    color: #00796b;
    cursor: pointer;
}

.difficulty-selector select:disabled {
    background-color: #f5f5f5;
    color: #999;
    cursor: not-allowed;
}

#puzzle-container {
    display: grid;
    border: 3px solid #00796b;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.15);
    transition: all 0.3s ease;
    /* Container background will be set dynamically by JavaScript */
}

.puzzle-2x2 {
    width: 220px;
    height: 220px;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, 1fr);
    gap: 0;
}

.puzzle-3x3 {
    width: 270px;
    height: 270px;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    gap: 0;
    margin: 20px auto;
}

.puzzle-4x4 {
    width: 320px;
    height: 320px;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
    gap: 0;
}

.puzzle-piece {
    width: 100%;
    height: 100%;
    border: 2px solid rgba(255, 255, 255, 0.8);
    cursor: pointer;
    box-sizing: border-box;
    transition: transform 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
    font-family: Arial, sans-serif;
    background-repeat: no-repeat;
    min-height: 85px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    word-break: break-word;
    overflow: hidden;
    /* --- CRITICAL ADDITIONS FOR EACH PUZZLE PIECE --- */
    /* Background image and size will be set dynamically by JavaScript */
    /* This ensures pieces show the correct parts of selected images */
    /* ------------------------------------------------ */
}

.puzzle-piece:hover {
    transform: scale(1.02);
    border-color: rgba(255, 171, 0, 0.6);
}

.puzzle-piece.selected {
    border: 3px solid #ffab00;
    box-shadow: 0 0 12px rgba(255, 171, 0, 0.8);
    transform: scale(1.05);
    z-index: 2;
}

#message {
    padding: 20px 30px;
    background-color: #c8e6c9;
    border-radius: 10px;
    font-size: 1.6em;
    font-weight: bold;
    color: #2e7d32;
    text-align: center;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    transition: opacity 0.6s ease-in-out;
    opacity: 1;
    pointer-events: auto;
    max-width: 400px;
    line-height: 1.4;
}

.hidden {
    opacity: 0 !important;
    pointer-events: none !important;
}

.controls {
    display: flex;
    gap: 15px;
    margin-top: 10px;
    flex-wrap: wrap;
    justify-content: center;
}

.puzzle-topic-selector {
    margin: 15px auto 10px;
    text-align: center;
    padding: 12px;
    background: #e3f2fd;
    border-radius: 8px;
    border: 1px solid #bbdefb;
    max-width: 350px;
}

.affirmation-theme-selector {
    margin: 10px auto 20px;
    text-align: center;
    padding: 12px;
    background: #f8f9fa;
    border-radius: 8px;
    border: 1px solid #e9ecef;
    max-width: 300px;
}

.affirmation-theme-selector label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #495057;
    font-size: 0.9em;
}

.topic-dropdown, .theme-dropdown {
    padding: 8px 12px;
    border: 1px solid #ced4da;
    border-radius: 4px;
    background: white;
    font-size: 0.9em;
    color: #495057;
    cursor: pointer;
    transition: border-color 0.2s;
    width: 100%;
    max-width: 220px;
}

.puzzle-topic-selector label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #1565c0;
    font-size: 0.95em;
}

.topic-dropdown:hover, .theme-dropdown:hover {
    border-color: #80bdff;
}

.topic-dropdown:focus, .theme-dropdown:focus {
    outline: none;
    border-color: #80bdff;
    box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25);
}

button {
    padding: 12px 25px;
    font-size: 1.1em;
    background-color: #009688;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    font-family: inherit;
    font-weight: 500;
}

button:hover {
    background-color: #00796b;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

button:active {
    transform: translateY(0);
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

button:focus {
    outline: 2px solid #4db6ac;
    outline-offset: 2px;
}

.resources-link {
    margin-top: 15px;
}

.resources-link a {
    color: #00796b;
    text-decoration: none;
    font-weight: bold;
    font-size: 0.95em;
    transition: color 0.2s ease;
    padding: 5px 10px;
    border-radius: 5px;
}

.resources-link a:hover {
    color: #004d40;
    text-decoration: underline;
    background-color: rgba(0, 121, 107, 0.1);
}

.resources-link a:focus {
    outline: 2px solid #4db6ac;
    outline-offset: 2px;
}

/* Success animation */
@keyframes celebration {
    0% { transform: scale(1); }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

.celebrate {
    animation: celebration 0.6s ease-in-out;
}

/* Responsive adjustments */
@media (max-width: 600px) {
    .puzzle-piece {
        font-size: 0.7em !important; /* Even smaller on mobile */
        padding: 2px;
        line-height: 1.1;
    }
    
    .puzzle-2x2 {
        width: 180px !important;
        height: 180px !important;
        grid-template-columns: repeat(2, 1fr) !important;
        grid-template-rows: repeat(2, 1fr) !important;
    }
    
    .puzzle-3x3 {
        width: 270px !important;
        height: 270px !important;
        grid-template-columns: repeat(3, 1fr) !important;
        grid-template-rows: repeat(3, 1fr) !important;
    }
    
    .puzzle-4x4 {
        width: 280px !important;
        height: 280px !important;
        grid-template-columns: repeat(4, 1fr) !important;
        grid-template-rows: repeat(4, 1fr) !important;
    }
    
    .game-area {
        padding: 15px;
        margin: 10px;
    }
    
    .header h1 {
        font-size: 2em;
    }
    
    #message {
        font-size: 1.3em;
        padding: 15px 20px;
    }
    
    button {
        padding: 10px 20px;
        font-size: 1em;
    }
    
    .controls {
        gap: 10px;
    }
    
    .difficulty-selector select {
        font-size: 0.9em;
        padding: 6px 12px;
    }
    
    .puzzle-topic-selector, .affirmation-theme-selector {
        max-width: 280px;
        padding: 8px;
        margin: 10px auto;
    }
    
    .topic-dropdown, .theme-dropdown {
        font-size: 0.8em;
        padding: 6px 8px;
    }
}

@media (max-width: 400px) {
    .puzzle-2x2 {
        width: 160px;
        height: 160px;
    }
    
    .puzzle-3x3 {
        width: 240px;
        height: 240px;
    }
    
    .puzzle-4x4 {
        width: 260px;
        height: 260px;
    }
    
    .header h1 {
        font-size: 1.8em;
    }
    
    #message {
        font-size: 1.2em;
        padding: 12px 16px;
    }
    
    .difficulty-selector {
        margin-bottom: 15px;
    }
    
    .difficulty-selector select {
        font-size: 0.85em;
        padding: 5px 10px;
    }
    
    .instructions {
        padding: 15px;
        margin-bottom: 15px;
    }
    
    .instructions h3 {
        font-size: 1.1em;
    }
    
    .instructions p {
        font-size: 0.85em;
    }
}

/* Image Selection Styles */
.image-selector {
    margin: 20px 0;
    text-align: center;
}

.image-selector h3 {
    font-size: 1.1em;
    font-weight: bold;
    color: #00796b;
    margin-bottom: 10px;
}

.image-buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
}

.image-btn {
    padding: 10px 20px;
    font-size: 1em;
    border: 2px solid #00796b;
    border-radius: 6px;
    background-color: white;
    color: #00796b;
    cursor: pointer;
    transition: all 0.3s ease;
}

.image-btn:hover {
    background-color: #e0f7fa;
}

.image-btn.active {
    background-color: #00796b;
    color: white;
}

.music-selector {
    margin: 10px 0;
    text-align: center;
    padding: 10px;
    background: #e8f5e8;
    border-radius: 8px;
    border: 1px solid #c8e6c9;
}

.music-dropdown {
    padding: 8px 12px;
    border: 2px solid #4CAF50;
    border-radius: 6px;
    font-size: 16px;
    background: white;
    margin-left: 10px;
    min-width: 150px;
}

/* Image puzzle specific styles */
.puzzle-piece svg {
    max-width: 100%;
    max-height: 100%;
    pointer-events: none;
}

.puzzle-piece:has(svg) {
    padding: 0;
    background-color: transparent;
}

/* Privacy Statement Styles */
.privacy-statement {
    margin-top: 20px;
    padding: 15px;
    background-color: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    max-width: 600px;
    text-align: center;
    font-size: 0.9em;
}

.privacy-statement p {
    margin: 0;
    color: #6c757d;
    line-height: 1.4;
}

/* Accessibility Improvements */
.controls button:focus,
.difficulty-selector select:focus,
.puzzle-topic-selector select:focus,
.affirmation-theme-selector select:focus,
.music-selector select:focus {
    outline: 3px solid #00796b;
    outline-offset: 2px;
}

body.dark-mode .controls button:focus,
body.dark-mode .difficulty-selector select:focus,
body.dark-mode .puzzle-topic-selector select:focus,
body.dark-mode .affirmation-theme-selector select:focus,
body.dark-mode .music-selector select:focus {
    outline: 3px solid #4db6ac;
    outline-offset: 2px;
}

/* Enhanced contrast for better readability */
.puzzle-piece {
    font-weight: bold;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.1);
}

body.dark-mode .puzzle-piece {
    text-shadow: 1px 1px 2px rgba(0,0,0,0.3);
}