* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-color: #f7f2e9;
    --container-bg: #fff;
    --text-color: #333;
    --primary-color: #e67e22;
    --primary-hover: #d35400;
    --border-color: #ddd;
    --stack-bg: #f8f8f8;
    --puzzle-bg: #f9f9f9;
    --modal-overlay: rgba(0, 0, 0, 0.8);
    --close-btn-bg: #fff;
    --close-btn-color: #333;
    --bg-secondary: #f0f0f0;
    --accent-color: #0000ff;
}

body.dark-mode {
    --bg-color: #121212;
    --container-bg: #1e1e1e;
    --text-color: #f0f0f0;
    --primary-color: #ff8c38;
    --primary-hover: #ff6a00;
    --border-color: #444;
    --stack-bg: #2a2a2a;
    --puzzle-bg: #2a2a2a;
    --modal-overlay: rgba(0, 0, 0, 0.9);
    --close-btn-bg: #333;
    --close-btn-color: #fff;
    --bg-secondary: #1a1a1a;
    --accent-color: #ffff00;
}

body {
    font-family: 'Arial', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background-color 0.3s ease;
}

.game-container {
    max-width: 1200px;
    width: 100%;
    margin: 20px;
    padding: 20px;
    background-color: var(--container-bg);
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: background-color 0.3s ease, color 0.3s ease;
}

h1 {
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 2.5rem;
}

.controls-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding: 0 10px;
}

.difficulty select {
    padding: 8px;
    border-radius: 5px;
    border: 1px solid var(--border-color);
    background-color: var(--container-bg);
    color: var(--text-color);
    font-size: 16px;
}

.game-controls {
    display: flex;
    gap: 10px;
    align-items: center;
}

/* Theme toggle switch */
.theme-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-right: 10px;
}

.theme-label {
    font-size: 14px;
    font-weight: bold;
}

.switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 24px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: .3s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: .3s;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:focus + .slider {
    box-shadow: 0 0 1px var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}

button {
    padding: 10px 15px;
    border: none;
    border-radius: 5px;
    background-color: var(--primary-color);
    color: white;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s;
}

button:hover {
    background-color: var(--primary-hover);
}

.custom-image-container {
    margin-bottom: 20px;
    padding: 15px;
    background-color: var(--stack-bg);
    border-radius: 5px;
}

.custom-image-container p {
    margin-bottom: 10px;
    font-weight: bold;
}

.image-input-container {
    display: flex;
    justify-content: center;
}

#custom-image-upload {
    padding: 10px;
    background-color: var(--container-bg);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    width: 100%;
    max-width: 300px;
    color: var(--text-color);
}

.stats-container {
    display: flex;
    align-items: center;
    gap: 20px;
    margin: 20px 0;
    position: relative;
    padding: 10px;
    background: var(--bg-secondary);
    border-radius: 8px;
    min-height: 60px;
}

.progress-bar {
    height: 10px;
    background: var(--accent-color);
    border-radius: 5px;
    transition: width 0.3s ease;
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0%;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

/* Add a container for the progress bar to make it more visible */
.progress-container {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 10px;
    background: rgba(0, 0, 0, 0.1);
    border-radius: 5px;
    overflow: hidden;
}

.puzzle-complete {
    animation: completePulse 1s ease-in-out;
}

@keyframes completePulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.02);
    }
    100% {
        transform: scale(1);
    }
}

.preview-container {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--modal-overlay);
    z-index: 1000;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.preview-container.show {
    display: flex;
}

#preview-image {
    max-width: 80%;
    max-height: 80%;
    margin-bottom: 20px;
    border: 5px solid white;
}

#close-preview {
    background-color: var(--close-btn-bg);
    color: var(--close-btn-color);
}

.game-play-area {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
}

.piece-stack-container {
    width: 200px;
    min-height: 400px;
    background-color: var(--stack-bg);
    border-radius: 10px;
    padding: 10px;
    position: relative;
    overflow-y: auto;
    max-height: 600px;
    border: 2px dashed var(--primary-color);
}

.puzzle-container {
    display: grid;
    margin: 0 auto;
    position: relative;
    width: 100%;
    max-width: 600px;
    aspect-ratio: 1/1;
    border: 2px solid var(--primary-color);
    background-color: var(--puzzle-bg);
}

.puzzle-piece {
    position: absolute;
    cursor: move;
    transition: transform 0.2s ease;
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

.puzzle-piece.selected {
    outline: 3px solid var(--accent-color);
    outline-offset: 2px;
    z-index: 1000;
}

.puzzle-piece.correct {
    cursor: default;
    outline: 2px solid #4CAF50;
}

/* Focus styles for keyboard navigation */
.puzzle-piece:focus {
    outline: 3px solid var(--accent-color);
    outline-offset: 2px;
    z-index: 1000;
}

/* High contrast mode adjustments */
@media (prefers-contrast: high) {
    .puzzle-piece.selected {
        outline: 4px solid var(--accent-color);
    }
    
    .puzzle-piece.correct {
        outline: 4px solid #00ff00;
    }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    .puzzle-piece {
        transition: none;
    }
    
    .puzzle-complete {
        animation: none;
    }
}

.puzzle-piece.in-stack {
    position: relative;
    margin: 5px auto;
    transform-origin: center;
    transition: all 0.3s ease;
}

.puzzle-piece:hover {
    z-index: 10;
}

/* Image selection modal with theme support */
.image-selection-modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: var(--modal-overlay);
    justify-content: center;
    align-items: center;
}

.modal-content {
    background-color: var(--container-bg);
    margin: 5% auto;
    width: 90%;
    max-width: 1000px;
    max-height: 80vh;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.modal-header {
    background-color: var(--primary-color);
    padding: 15px;
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    margin: 0;
    font-size: 1.5rem;
}

.close-modal {
    color: white;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
}

.close-modal:hover {
    color: #f0f0f0;
}

.image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 15px;
    padding: 20px;
    overflow-y: auto;
    max-height: calc(80vh - 70px);
    background-color: var(--container-bg);
}

.image-item {
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
    background-color: var(--stack-bg);
}

.image-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
}

.image-item img {
    width: 100%;
    height: 140px;
    object-fit: cover;
    border-bottom: 2px solid var(--primary-color);
}

.image-name {
    padding: 10px;
    font-size: 14px;
    text-align: center;
    font-weight: bold;
    color: var(--text-color);
}

@media (max-width: 992px) {
    .game-play-area {
        flex-direction: column;
        align-items: center;
    }
    
    .piece-stack-container {
        width: 100%;
        max-width: 600px;
        min-height: 150px;
        max-height: 200px;
        margin-bottom: 20px;
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        overflow-x: auto;
    }
    
    .puzzle-piece.in-stack {
        margin: 5px;
    }
}

@media (max-width: 768px) {
    .controls-container {
        flex-direction: column;
        gap: 15px;
    }
    
    .game-controls {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .theme-toggle {
        margin-bottom: 10px;
    }
    
    .puzzle-container {
        max-width: 95%;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .image-input-container {
        flex-direction: column;
        align-items: stretch;
    }
    
    .or-text {
        align-self: center;
        margin: 5px 0;
    }
    
    .image-grid {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    }
    
    .image-item img {
        height: 100px;
    }
    
    .image-name {
        font-size: 12px;
        padding: 8px 5px;
    }
}

/* High contrast mode */
@media (prefers-contrast: high) {
    :root {
        --text-color: #000000;
        --bg-color: #ffffff;
        --bg-secondary: #f0f0f0;
        --accent-color: #0000ff;
        --border-color: #000000;
    }

    .dark-mode {
        --text-color: #ffffff;
        --bg-color: #000000;
        --bg-secondary: #1a1a1a;
        --accent-color: #ffff00;
        --border-color: #ffffff;
    }
}

/* Focus styles for accessibility */
button:focus,
select:focus,
input:focus {
    outline: 3px solid var(--accent-color);
    outline-offset: 2px;
}

/* Screen reader only text */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.puzzle-piece.hint {
    animation: hintPulse 1s infinite;
    box-shadow: 0 0 10px 5px var(--accent-color);
    z-index: 1000;
}

.hint-highlight {
    position: absolute;
    background-color: rgba(255, 255, 0, 0.3);
    border: 2px dashed var(--accent-color);
    pointer-events: none;
    animation: hintPulse 1s infinite;
    z-index: 5;
}

@keyframes hintPulse {
    0% {
        opacity: 0.7;
    }
    50% {
        opacity: 1;
    }
    100% {
        opacity: 0.7;
    }
}

#hint-button {
    background-color: var(--accent-color);
    color: white;
    position: relative;
}

#hint-button::after {
    content: attr(title);
    position: absolute;
    bottom: -30px;
    left: 50%;
    transform: translateX(-50%);
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 5px 10px;
    border-radius: 5px;
    font-size: 12px;
    white-space: nowrap;
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
}

#hint-button:hover::after {
    opacity: 1;
}

/* High Scores Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: var(--modal-overlay);
    overflow: auto;
}

.modal-content {
    background-color: var(--container-bg);
    margin: 5% auto;
    padding: 20px;
    border-radius: 10px;
    width: 80%;
    max-width: 600px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    position: relative;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    margin: 0;
    color: var(--primary-color);
}

.close-modal {
    color: var(--text-color);
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
}

.close-modal:hover {
    color: var(--primary-hover);
}

.high-scores-container {
    max-height: 400px;
    overflow-y: auto;
}

.high-scores-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
}

.high-scores-table th,
.high-scores-table td {
    padding: 10px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.high-scores-table th {
    background-color: var(--stack-bg);
    font-weight: bold;
}

.high-scores-table tr:hover {
    background-color: var(--stack-bg);
}

#high-scores-button {
    background-color: var(--primary-color);
    color: white;
}

/* Responsive adjustments for high scores */
@media (max-width: 768px) {
    .high-scores-table {
        font-size: 14px;
    }
    
    .high-scores-table th,
    .high-scores-table td {
        padding: 8px 5px;
    }
}