/* Variables CSS */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #8b5cf6;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --dark-bg: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.8);
    --text: #f1f5f9;
    --text-dim: #94a3b8;
    --border: rgba(148, 163, 184, 0.2);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
    --radius: 16px;
}

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

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
    min-height: 100vh;
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Page Container */
.page {
    display: none;
    min-height: 100vh;
}

.page.active {
    display: block;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 30px 20px;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 60px;
}

.title {
    font-size: 4.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #6366f1, #8b5cf6, #ec4899);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 15px;
    letter-spacing: -0.02em;
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-dim);
    font-weight: 400;
}

/* Preview Grid */
.game-preview {
    display: flex;
    justify-content: center;
    margin-bottom: 30px;
}

.home-main {
    margin-bottom: 40px;
}

.welcome-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 40px;
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    gap: 3px;
    background: var(--card-bg);
    padding: 10px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    max-width: 300px;
}

.preview-cell {
    aspect-ratio: 1;
    background: rgba(255, 255, 255, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text);
    min-height: 28px;
    border-radius: 4px;
}

/* Quick Start Section */
.quick-start {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    padding: 40px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    max-width: 550px;
    margin: 0 auto 40px auto;
    box-shadow: var(--shadow-lg);
}

.quick-start h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 30px;
    color: var(--text);
    text-align: center;
}

/* Difficulty Buttons */
.difficulty-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.difficulty-btn {
    padding: 14px 28px;
    border: 2px solid var(--border);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.05);
    cursor: pointer !important;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    font-size: 1rem;
    color: var(--text);
    min-width: 130px;
    justify-content: center;
    position: relative;
    z-index: 1;
}

.difficulty-btn:hover {
    transform: translateY(-3px);
    border-color: var(--primary);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.3);
    background: rgba(99, 102, 241, 0.1);
}

.difficulty-btn.selected {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    border-color: transparent;
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.5);
}

.btn-icon {
    font-size: 1.4rem;
}

.btn-text {
    font-size: 1rem;
}

/* Buttons */
.btn {
    padding: 14px 28px;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer !important;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    position: relative;
    z-index: 1;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(255, 255, 255, 0.1);
}

.btn-large {
    padding: 18px 50px;
    font-size: 1.4rem;
    font-weight: 700;
    width: 100%;
    justify-content: center;
}

.btn-large:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 35px rgba(99, 102, 241, 0.6);
}

/* Game Page */
.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 20px;
}

.game-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text);
}

.game-stats {
    display: flex;
    gap: 15px;
}

.stat {
    background: var(--card-bg);
    padding: 12px 24px;
    border-radius: 12px;
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.95rem;
}

.stat-label {
    color: var(--text-dim);
    font-weight: 500;
}

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

.stat-value.error {
    color: var(--danger);
}

.stat-value.warning {
    color: var(--warning);
}

/* Game Controls */
.game-controls {
    background: var(--card-bg);
    padding: 25px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    margin-bottom: 30px;
    display: flex;
    justify-content: center;
}

.game-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

/* Game Info */
.game-info {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.timer, .score {
    background: var(--card-bg);
    padding: 20px 35px;
    border-radius: 12px;
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.1rem;
    font-weight: 600;
}

.timer-label, .score-label {
    color: var(--text-dim);
}

/* Sudoku Board */
.game-board-container {
    display: flex;
    justify-content: center;
    margin-bottom: 40px;
}

.sudoku-board {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    gap: 3px;
    background: var(--card-bg);
    padding: 12px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    max-width: 520px;
    width: 100%;
    margin: 0 auto;
}

.cell {
    aspect-ratio: 1;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 1.6rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
    color: var(--text);
    min-height: 0;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.cell:hover {
    background: rgba(99, 102, 241, 0.2);
}

.cell.selected {
    background: rgba(99, 102, 241, 0.3);
    border: 2px solid var(--primary);
    box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.2);
}

.cell.given {
    background: rgba(30, 41, 59, 0.8);
    color: var(--text-dim);
    cursor: default;
}

.cell.user-input {
    color: var(--primary-light);
}

.cell.error {
    background: rgba(239, 68, 68, 0.2);
    color: var(--danger);
}

.cell.correct {
    background: rgba(16, 185, 129, 0.3);
    color: var(--success);
}

.cell.locked {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.3), rgba(5, 150, 105, 0.3));
    color: var(--success);
    font-weight: 700;
    cursor: not-allowed;
    border: 2px solid var(--success);
}

.cell.error-permanent {
    background: rgba(239, 68, 68, 0.3);
    color: var(--danger);
    border: 2px solid var(--danger);
    animation: shake 0.5s;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-8px); }
    75% { transform: translateX(8px); }
}

/* Board 3x3 borders - Plus visibles */
/* Bordures verticales entre colonnes */
.cell:nth-child(3n) {
    border-right: 4px solid rgba(255, 255, 255, 0.3) !important;
}

/* Bordures horizontales entre lignes */
.cell:nth-child(n+19):nth-child(-n+27),
.cell:nth-child(n+46):nth-child(-n+54) {
    border-bottom: 4px solid rgba(255, 255, 255, 0.3) !important;
}

/* Bordures des coins (plus visibles) */
.cell:nth-child(3n):nth-child(n+19):nth-child(-n+27),
.cell:nth-child(3n):nth-child(n+46):nth-child(-n+54) {
    border-right: 4px solid rgba(99, 102, 241, 0.7) !important;
    border-bottom: 4px solid rgba(99, 102, 241, 0.7) !important;
}

/* Fonds alternés pour les blocs 3x3 */
.cell:nth-child(n+1):nth-child(-n+3),
.cell:nth-child(n+10):nth-child(-n+12),
.cell:nth-child(n+19):nth-child(-n+21),
.cell:nth-child(n+28):nth-child(-n+30),
.cell:nth-child(n+37):nth-child(-n+39),
.cell:nth-child(n+46):nth-child(-n+48),
.cell:nth-child(n+55):nth-child(-n+57),
.cell:nth-child(n+64):nth-child(-n+66),
.cell:nth-child(n+73):nth-child(-n+75) {
    background: rgba(30, 41, 59, 0.9) !important;
}

.cell:nth-child(n+4):nth-child(-n+6),
.cell:nth-child(n+13):nth-child(-n+15),
.cell:nth-child(n+22):nth-child(-n+24),
.cell:nth-child(n+31):nth-child(-n+33),
.cell:nth-child(n+40):nth-child(-n+42),
.cell:nth-child(n+49):nth-child(-n+51),
.cell:nth-child(n+58):nth-child(-n+60),
.cell:nth-child(n+67):nth-child(-n+69),
.cell:nth-child(n+76):nth-child(-n+78) {
    background: rgba(15, 23, 42, 0.9) !important;
}

/* Number Pad */
.number-pad {
    background: var(--card-bg);
    padding: 30px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    margin-bottom: 40px;
    text-align: center;
}

.number-pad-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 25px;
    color: var(--text);
}

.number-buttons {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 15px;
    max-width: 450px;
    margin: 0 auto;
}

.number-btn {
    padding: 18px;
    border: 2px solid var(--border);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.05);
    font-size: 1.3rem;
    font-weight: 600;
    cursor: pointer !important;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    color: var(--text);
    position: relative;
    z-index: 1;
}

.number-btn:hover:not(:disabled) {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    transform: translateY(-5px) scale(1.05);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.4);
    border-color: transparent;
}

.number-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.clear-btn {
    background: linear-gradient(135deg, var(--danger), #dc2626);
    color: white;
    border-color: transparent;
}

.clear-btn:hover {
    box-shadow: 0 10px 30px rgba(239, 68, 68, 0.5);
}

/* Leaderboard */
.leaderboard {
    background: var(--card-bg);
    padding: 35px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    margin-top: 40px;
}

.leaderboard h3 {
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 30px;
    color: var(--text);
}

.leaderboard-tabs {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.tab-btn {
    padding: 12px 24px;
    border: 2px solid var(--border);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.05);
    cursor: pointer !important;
    transition: all 0.3s;
    font-weight: 600;
    font-size: 1rem;
    color: var(--text);
    position: relative;
    z-index: 1;
}

.tab-btn:hover {
    background: rgba(99, 102, 241, 0.2);
    border-color: var(--primary);
    transform: translateY(-2px);
}

.tab-btn.active {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    border-color: transparent;
}

.leaderboard-content {
    min-height: 200px;
}

.leaderboard-entry {
    display: grid;
    grid-template-columns: 50px 1fr 100px 110px 130px 100px;
    gap: 15px;
    align-items: center;
    padding: 18px 20px;
    margin-bottom: 12px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 12px;
    border-left: 4px solid var(--primary);
    transition: all 0.3s;
}

.leaderboard-entry:hover {
    transform: translateX(5px);
    background: rgba(255, 255, 255, 0.06);
}

.leaderboard-entry:nth-child(1) {
    border-left-color: #fbbf24;
    background: linear-gradient(90deg, rgba(251, 191, 36, 0.15) 0%, rgba(255, 255, 255, 0.03) 100%);
}

.leaderboard-entry:nth-child(2) {
    border-left-color: #94a3b8;
}

.leaderboard-entry:nth-child(3) {
    border-left-color: #cd7c2f;
}

.entry-rank {
    font-weight: 700;
    font-size: 1.3rem;
    color: var(--primary);
}

.entry-name {
    font-weight: 600;
    color: var(--text);
}

.entry-time {
    color: var(--text-dim);
    font-size: 0.9rem;
}

.entry-errors {
    color: var(--text-dim);
    font-size: 0.9rem;
}

.entry-date {
    color: var(--text-dim);
    font-size: 0.9rem;
}

.entry-score {
    color: var(--success);
    font-weight: 700;
}

/* Modals */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(8px);
}

.modal-content {
    background: var(--card-bg);
    border: 1px solid var(--border);
    margin: 10% auto;
    padding: 40px;
    border-radius: var(--radius);
    width: 90%;
    max-width: 480px;
    text-align: center;
    animation: modalIn 0.3s;
}

@keyframes modalIn {
    from {
        opacity: 0;
        transform: translateY(-30px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal-content h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--success);
}

.completion-stats {
    background: rgba(255, 255, 255, 0.05);
    padding: 25px;
    border-radius: 12px;
    margin: 25px 0;
}

.completion-stats p {
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.player-name-input {
    margin: 25px 0;
    display: flex;
    gap: 12px;
}

.player-name-input input {
    flex: 1;
    padding: 12px 18px;
    border: 2px solid var(--border);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.05);
    color: white;
    font-size: 1rem;
}

.player-name-input input:focus {
    outline: none;
    border-color: var(--primary);
}

/* Game Over Modal */
.game-over-modal {
    text-align: center;
}

.game-over-icon {
    font-size: 5rem;
    margin-bottom: 20px;
    animation: bounce 1s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-20px); }
    60% { transform: translateY(-10px); }
}

.game-over-modal h2 {
    color: var(--danger);
    font-size: 2.5rem;
}

.game-over-stats {
    background: rgba(239, 68, 68, 0.1);
    padding: 25px;
    border-radius: 12px;
    margin: 25px 0;
    border-left: 4px solid var(--danger);
}

.game-over-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-top: 30px;
}

/* Confirm Modal */
.confirm-modal {
    text-align: center;
}

.confirm-icon {
    font-size: 4rem;
    margin-bottom: 20px;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.confirm-modal h2 {
    color: var(--warning);
}

.confirm-stats {
    background: rgba(245, 158, 11, 0.1);
    padding: 25px;
    border-radius: 12px;
    margin: 25px 0;
    border-left: 4px solid var(--warning);
}

.confirm-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-top: 30px;
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger), #dc2626);
    color: white;
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(239, 68, 68, 0.5);
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 15px 10px;
    }
    
    .title {
        font-size: 2.5rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .header {
        margin-bottom: 30px;
    }
    
    /* Preview Grid plus petit */
    .preview-grid {
        max-width: 240px;
        padding: 8px;
        gap: 2px;
    }
    
    .preview-cell {
        font-size: 0.75rem;
        min-height: 22px;
    }
    
    /* Quick Start */
    .quick-start {
        padding: 25px 20px;
    }
    
    .quick-start h3 {
        font-size: 1.2rem;
        margin-bottom: 20px;
    }
    
    .difficulty-buttons {
        flex-direction: column;
        gap: 10px;
    }
    
    .difficulty-btn {
        width: 100%;
        padding: 12px 20px;
        min-width: auto;
    }
    
    .btn-icon {
        font-size: 1.2rem;
    }
    
    .btn-large {
        padding: 15px 30px;
        font-size: 1.1rem;
    }
    
    /* Game Header */
    .game-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 15px;
    }
    
    .game-title {
        font-size: 1.5rem;
    }
    
    .game-stats {
        width: 100%;
        justify-content: center;
    }
    
    .stat {
        padding: 10px 16px;
        font-size: 0.85rem;
    }
    
    /* Game Controls */
    .game-controls {
        padding: 15px;
    }
    
    .game-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .game-buttons .btn {
        width: 100%;
        justify-content: center;
    }
    
    /* Game Info */
    .game-info {
        flex-direction: row;
        gap: 10px;
    }
    
    .timer, .score {
        flex: 1;
        padding: 15px 20px;
        font-size: 0.95rem;
        justify-content: center;
    }
    
    .timer-label, .score-label {
        font-size: 0.9rem;
    }
    
    /* Sudoku Board */
    .sudoku-board {
        padding: 8px;
        gap: 2px;
        max-width: 100%;
    }
    
    .cell {
        font-size: 1.2rem;
        border-width: 1px;
    }
    
    /* Ajuster les bordures des blocs 3x3 pour mobile */
    .cell:nth-child(3n) {
        border-right: 3px solid rgba(255, 255, 255, 0.25) !important;
    }
    
    .cell:nth-child(n+19):nth-child(-n+27),
    .cell:nth-child(n+46):nth-child(-n+54) {
        border-bottom: 3px solid rgba(255, 255, 255, 0.25) !important;
    }
    
    /* Number Pad */
    .number-pad {
        padding: 20px 15px;
    }
    
    .number-pad-title {
        font-size: 1rem;
        margin-bottom: 15px;
    }
    
    .number-buttons {
        grid-template-columns: repeat(5, 1fr);
        gap: 8px;
        max-width: 100%;
    }
    
    .number-btn {
        padding: 12px 8px;
        font-size: 1.1rem;
    }
    
    /* Leaderboard */
    .leaderboard {
        padding: 20px 15px;
    }
    
    .leaderboard h3 {
        font-size: 1.5rem;
        margin-bottom: 20px;
    }
    
    .leaderboard-tabs {
        gap: 8px;
    }
    
    .tab-btn {
        padding: 10px 16px;
        font-size: 0.9rem;
    }
    
    .leaderboard-entry {
        grid-template-columns: 40px 1fr 80px;
        gap: 10px;
        padding: 12px 15px;
    }
    
    .entry-rank {
        font-size: 1.1rem;
    }
    
    .entry-name {
        font-size: 0.9rem;
    }
    
    .entry-time,
    .entry-errors,
    .entry-date {
        display: none;
    }
    
    .entry-score {
        font-size: 0.9rem;
    }
    
    /* Modal */
    .modal-content {
        margin: 5% auto;
        padding: 25px 20px;
        width: 95%;
    }
    
    .modal-content h2 {
        font-size: 1.5rem;
    }
    
    .completion-stats,
    .game-over-stats,
    .confirm-stats {
        padding: 15px;
    }
    
    .completion-stats p {
        font-size: 1rem;
    }
    
    .player-name-input {
        flex-direction: column;
    }
    
    .player-name-input input {
        width: 100%;
    }
    
    .player-name-input .btn {
        width: 100%;
    }
    
    .game-over-icon {
        font-size: 3.5rem;
    }
    
    .game-over-modal h2 {
        font-size: 1.8rem;
    }
    
    .game-over-actions,
    .confirm-actions {
        flex-direction: column;
        width: 100%;
    }
    
    .game-over-actions .btn,
    .confirm-actions .btn {
        width: 100%;
    }
    
    .confirm-icon {
        font-size: 3rem;
    }
}

@media (max-width: 480px) {
    .title {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 0.9rem;
    }
    
    .sudoku-board {
        padding: 6px;
        gap: 1.5px;
    }
    
    .cell {
        font-size: 1rem;
    }
    
    /* Bordures plus fines sur petits écrans */
    .cell:nth-child(3n) {
        border-right: 2px solid rgba(255, 255, 255, 0.2) !important;
    }
    
    .cell:nth-child(n+19):nth-child(-n+27),
    .cell:nth-child(n+46):nth-child(-n+54) {
        border-bottom: 2px solid rgba(255, 255, 255, 0.2) !important;
    }
    
    .number-buttons {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .number-btn {
        padding: 14px 10px;
        font-size: 1.2rem;
    }
    
    .clear-btn {
        grid-column: span 3;
    }
    
    .leaderboard-entry {
        grid-template-columns: 35px 1fr 70px;
        padding: 10px 12px;
    }
    
    .entry-rank {
        font-size: 1rem;
    }
    
    .entry-name {
        font-size: 0.85rem;
    }
    
    .entry-time,
    .entry-errors,
    .entry-date {
        display: none;
    }
    
    .entry-score {
        font-size: 0.85rem;
    }
}

@media (max-width: 360px) {
    .container {
        padding: 10px 5px;
    }
    
    .title {
        font-size: 1.8rem;
    }
    
    .quick-start {
        padding: 20px 15px;
    }
    
    .sudoku-board {
        padding: 5px;
        gap: 1px;
    }
    
    .cell {
        font-size: 0.85rem;
    }
    
    /* Bordures encore plus fines sur très petits écrans */
    .cell:nth-child(3n) {
        border-right: 2px solid rgba(255, 255, 255, 0.15) !important;
    }
    
    .cell:nth-child(n+19):nth-child(-n+27),
    .cell:nth-child(n+46):nth-child(-n+54) {
        border-bottom: 2px solid rgba(255, 255, 255, 0.15) !important;
    }
    
    .number-btn {
        padding: 12px 6px;
        font-size: 1rem;
    }
    
    .game-info {
        gap: 8px;
    }
    
    .timer, .score {
        padding: 12px 15px;
        font-size: 0.85rem;
    }
}