/* ========================================
   數獨遊戲 - 主要樣式
   ======================================== */

/* CSS Variables - Base Theme */
:root {
    /* Colors */
    --bg-primary: #f5f5f0;
    --bg-secondary: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --accent-color: #4a90a4;
    --error-color: #e74c3c;
    --success-color: #27ae60;
    --border-color: #cccccc;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Typography */
    --font-primary: 'Noto Sans TC', sans-serif;
    --font-handwriting: 'Caveat', cursive;
    --font-pixel: 'Press Start 2P', cursive;

    /* Sizing */
    --cell-size: 42px;
    --board-gap: 1px;
    --border-radius: 8px;

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.2);

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
}

/* Reset & Base */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: var(--spacing-md);
}

/* App Container */
#app {
    width: 100%;
    max-width: 480px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: transparent;
    /* Changed from var(--bg-secondary) to generic background */
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    position: relative;
    /* Ensure background is positioned relative to app */
    z-index: 0;
}

/* Game Background */
#game-background {
    /* display: none; Removed debug */
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    /* Correct z-index to be behind content */
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    transition: background-image 0.5s ease-in-out;
}

/* Header */
#game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--bg-secondary);
    border-bottom: 2px solid var(--border-color);
    position: relative;
    z-index: 2;
    /* Ensure header is above background */
}

#game-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
}

#header-controls {
    display: flex;
    gap: var(--spacing-sm);
}

.icon-btn {
    width: 40px;
    height: 40px;
    border: none;
    background-color: transparent;
    border-radius: 50%;
    font-size: 1.25rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    background-color: rgba(0, 0, 0, 0.1);
    transform: scale(1.1);
}

.icon-btn.muted {
    opacity: 0.5;
}

/* Main Game Area */
#game-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: var(--spacing-md);
    gap: var(--spacing-md);
    position: relative;
    /* Ensure it creates a context above background */
    z-index: 1;
}

/* Stats Bar */
#stats-bar {
    display: flex;
    justify-content: space-around;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--bg-primary);
    border-radius: var(--border-radius);
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* Sudoku Board Container */
#sudoku-container {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-md);
    position: relative;
    z-index: 1;
    /* Ensure board is above background */
}



/* Sudoku Board */
#sudoku-board {
    display: grid;
    grid-template-columns: repeat(9, var(--cell-size));
    grid-template-rows: repeat(9, var(--cell-size));
    gap: var(--board-gap);
    background-color: transparent !important;
    /* Force transparent to override themes */
    border: 3px solid var(--text-primary);
    border-radius: 4px;
    padding: 2px;
    position: relative;
    /* Make board background transparent for gaps */
}

/* Override theme backgrounds */
.theme-paper #app,
.theme-custom #app {
    background-image: none !important;
    background-color: transparent !important;
}

.theme-paper #sudoku-board,
.theme-custom #sudoku-board {
    background-color: transparent !important;
    box-shadow: none !important;
    /* Remove pencil shadow to clear interference */
}

/* Sudoku Cells */
.sudoku-cell {
    width: var(--cell-size);
    height: var(--cell-size);
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-secondary, #ffffff);
    color: var(--text-primary, #000000);
    font-size: 1.5rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    z-index: 2;
    user-select: none;
}

.sudoku-cell.revealed {
    background-color: transparent !important;
    /* Fully transparent when revealed */
    background-image: none !important;
}

.sudoku-cell.box-completed {
    border: 2px solid #ffd700 !important;
    /* Gold border for confirmed completion */
    box-shadow: inset 0 0 10px rgba(255, 215, 0, 0.5);
}

.sudoku-cell:hover {
    filter: brightness(0.95);
}

.sudoku-cell.selected {
    background-color: var(--accent-color, #a3d5e4);
    opacity: 0.85;
}

.sudoku-cell.highlighted {
    background-color: var(--accent-color, #d4ecf4);
    opacity: 0.7;
}

.sudoku-cell.fixed {
    font-weight: 700;
}

.sudoku-cell.user-input {
    color: var(--accent-color);
}

.sudoku-cell.error {
    color: var(--error-color);
    background-color: rgba(248, 215, 218, 0.8);
}

.sudoku-cell.correct-animation {
    animation: correctPulse 0.3s ease;
}

/* 3x3 Box Borders */
.sudoku-cell:nth-child(3n) {
    border-right: 2px solid var(--text-primary);
}

.sudoku-cell:nth-child(9n) {
    border-right: none;
}

.sudoku-cell:nth-child(n+19):nth-child(-n+27),
.sudoku-cell:nth-child(n+46):nth-child(-n+54) {
    border-bottom: 2px solid var(--text-primary);
}

/* Number Pad */
#number-pad {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
}

.num-btn {
    height: 50px;
    border: 2px solid var(--border-color);
    background-color: var(--bg-secondary);
    border-radius: var(--border-radius);
    font-size: 1.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.num-btn:hover {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    transform: translateY(-2px);
}

.num-btn:active {
    transform: translateY(0);
}

.num-btn.erase-btn {
    background-color: #f0f0f0;
}

.num-btn.erase-btn:hover {
    background-color: var(--error-color);
    border-color: var(--error-color);
}

/* Control Buttons */
#control-buttons {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
}

.control-btn {
    flex: 1;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    background-color: var(--bg-secondary);
    border-radius: var(--border-radius);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.control-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.control-btn.primary {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

.control-btn.primary:hover {
    background-color: #3d7a8c;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 1;
    transition: opacity var(--transition-normal);
}

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

.modal-content {
    background-color: var(--bg-secondary);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    max-width: 400px;
    width: 90%;
    text-align: center;
    transform: scale(1);
    transition: transform var(--transition-normal);
}

.modal.hidden .modal-content {
    transform: scale(0.9);
}

.modal-content h2 {
    margin-bottom: var(--spacing-lg);
    font-size: 1.5rem;
}

.modal-close {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-sm) var(--spacing-lg);
    border: 2px solid var(--border-color);
    background-color: transparent;
    border-radius: var(--border-radius);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background-color: var(--text-primary);
    color: var(--bg-secondary);
}

/* Difficulty Options */
.difficulty-options {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.difficulty-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    background-color: var(--bg-secondary);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
}

.difficulty-btn:hover {
    border-color: var(--accent-color);
    background-color: rgba(74, 144, 164, 0.1);
    transform: translateX(4px);
}

.diff-icon {
    font-size: 2rem;
}

.diff-name {
    font-size: 1.25rem;
    font-weight: 600;
}

.diff-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Theme Store */
.theme-store {
    max-width: 500px;
}

.current-points {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-secondary);
}

.current-points span {
    font-weight: 700;
    color: var(--accent-color);
}

#theme-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
    max-height: 400px;
    overflow-y: auto;
    padding: var(--spacing-sm);
}

.theme-card {
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
}

.theme-card:hover {
    border-color: var(--accent-color);
    transform: translateY(-2px);
}

.theme-card.locked {
    opacity: 0.7;
}

.theme-card.active {
    border-color: var(--success-color);
    box-shadow: 0 0 0 2px var(--success-color);
}

.theme-icon {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
}

.theme-name {
    font-weight: 600;
    font-size: 0.9rem;
}

.theme-cost {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
}

.theme-card .lock-icon {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    font-size: 1rem;
}

/* Victory Modal */
.victory h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

#victory-stats {
    background-color: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-md);
}

#victory-stats p {
    margin: var(--spacing-sm) 0;
    font-size: 1.1rem;
}

#victory-stats span {
    font-weight: 700;
    color: var(--accent-color);
}

#unlock-notification {
    background-color: rgba(39, 174, 96, 0.1);
    border: 2px solid var(--success-color);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-md);
}

#unlock-notification p {
    color: var(--success-color);
    font-weight: 600;
}

/* Settings */
.setting-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--border-color);
}

.setting-item:last-of-type {
    border-bottom: none;
}

.setting-item label {
    font-size: 1rem;
}

.setting-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

/* Responsive Design */
@media (max-width: 400px) {
    :root {
        --cell-size: 36px;
    }

    #game-title {
        font-size: 1.5rem;
    }

    .num-btn {
        height: 44px;
        font-size: 1.25rem;
    }
}

@media (min-width: 600px) {
    :root {
        --cell-size: 48px;
    }

    body {
        padding: var(--spacing-xl);
        align-items: center;
    }

    #app {
        min-height: auto;
    }
}

/* Victory Actions */
.victory-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    margin-top: var(--spacing-md);
}

#btn-download-bg {
    background-color: var(--success-color);
    color: white;
    border-color: var(--success-color);
}

#btn-download-bg:hover {
    background-color: #219150;
    transform: translateY(-2px);
}

/* Gallery Styles */
.gallery-modal {
    max-width: 800px;
    width: 90%;
}

#gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: var(--spacing-md);
    padding: var(--spacing-sm);
    max-height: 60vh;
    overflow-y: auto;
}

.gallery-item {
    background-color: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    flex-direction: column;
}

.gallery-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
    border-color: var(--accent-color);
}

.gallery-item img {
    width: 100%;
    aspect-ratio: 1;
    object-fit: cover;
    display: block;
}

.gallery-date {
    padding: 4px;
    font-size: 0.8rem;
    text-align: center;
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    color: var(--text-primary);
    font-weight: 500;
}