/* Style Minimaliste, Moderne et Épuré */
:root {
    --primary: #0f172a;
    --primary-hover: #1e293b;
    --success: #10b981;
    --success-hover: #059669;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #334155;
    --text-dark: #0f172a;
    --text-muted: #64748b;
    --border: #e2e8f0;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Barre de navigation */
.navbar {
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-left, .nav-right, #user-logged-in, #user-guest {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-branding {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.logo-img {
    height: 32px;
    width: auto;
    object-fit: contain;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-dark);
    letter-spacing: -0.025em;
}

/* Boutons et éléments cliquables */
button {
    cursor: pointer;
    border: none;
    border-radius: 6px;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    transition: background-color 0.2s, color 0.2s;
}

.btn-nav {
    background: none;
    color: var(--text-main);
}
.btn-nav:hover {
    color: var(--text-dark);
}

.btn-primary { background-color: var(--primary); color: white; }
.btn-primary:hover { background-color: var(--primary-hover); }
.btn-success { background-color: var(--success); color: white; }
.btn-success:hover { background-color: var(--success-hover); }
.btn-secondary { background-color: #ffffff; color: var(--text-dark); border: 1px solid var(--border); }
.btn-secondary:hover { background-color: #f8fafc; border-color: #cbd5e1; }
.btn-text { background: none; color: var(--text-muted); }
.btn-text:hover { color: var(--text-dark); }
.btn-admin { background-color: #ef4444; color: white; }
.btn-admin:hover { background-color: #dc2626; }
.w-full { width: 100%; padding: 0.625rem; margin-top: 1rem; font-size: 0.95rem; }

/* Conteneur et mise en page */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 3rem 2rem;
    flex: 1;
    width: 100%;
}

.page { display: none; }
.page.active { display: block; }
.hidden { display: none !important; }

/* Accueil */
.hero { text-align: center; margin-bottom: 4rem; }
.hero h2 { font-size: 2.25rem; color: var(--text-dark); font-weight: 800; margin-bottom: 0.5rem; letter-spacing: -0.025em; }
.hero p { color: var(--text-muted); font-size: 1.05rem; }

.game-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}
.card h3 { color: var(--text-dark); font-size: 1.25rem; margin-bottom: 0.5rem; }
.card p { color: var(--text-muted); font-size: 0.875rem; line-height: 1.5; }

/* Structures d'authentification */
.auth-box {
    max-width: 360px;
    margin: 4rem auto 0 auto;
    background: var(--card-bg);
    padding: 2.5rem;
    border-radius: 12px;
    border: 1px solid var(--border);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}
.auth-box h2 { text-align: center; margin-bottom: 2rem; color: var(--text-dark); font-size: 1.5rem; }

.input-group { margin-bottom: 1.25rem; }
.input-group label { display: block; margin-bottom: 0.375rem; font-size: 0.84rem; font-weight: 600; color: var(--text-dark); }
.input-group input {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    outline: none;
    font-size: 0.95rem;
    color: var(--text-dark);
    background-color: #f8fafc;
}
.input-group input:focus { border-color: #94a3b8; background-color: #ffffff; }

/* Alertes */
.alert {
    padding: 0.875rem;
    border-radius: 6px;
    margin-bottom: 2rem;
    text-align: center;
    font-size: 0.9rem;
    font-weight: 500;
}
.alert.error { background-color: #fef2f2; color: #991b1b; border: 1px solid #fca5a5; }
.alert.success { background-color: #f0fdf4; color: #166534; border: 1px solid #86efac; }

/* Grille Sudoku */
.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 1rem;
}
.game-header h2 { font-size: 1.75rem; color: var(--text-dark); }

.sudoku-board {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    width: 440px;
    height: 440px;
    margin: 0 auto;
    border: 3px solid #0f172a;
    background-color: #0f172a;
    gap: 1px;
    border-radius: 4px;
    overflow: hidden;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.sudoku-cell {
    background-color: white;
    width: 100%;
    height: 100%;
    font-size: 1.4rem;
    text-align: center;
    border: none;
    outline: none;
    color: #334155;
}

.sudoku-cell:nth-child(3n) { border-right: 2px solid #0f172a; }
.sudoku-cell:nth-child(9n) { border-right: none; }
.sudoku-row-3 .sudoku-cell, .sudoku-row-6 .sudoku-cell { border-bottom: 2px solid #0f172a; }

.sudoku-cell:focus { background-color: #f0fdf4; }
.sudoku-cell.readonly { background-color: #f8fafc; font-weight: 700; color: #0f172a; }
.sudoku-cell.error { color: #ef4444; background-color: #fef2f2; }

.footer {
    text-align: center;
    padding: 2rem;
    font-size: 0.75rem;
    color: var(--text-muted);
    border-top: 1px solid var(--border);
    background-color: #ffffff;
}

/* Règles CSS strictes pour l'impression A4 */
@media print {
    .navbar, .game-header button, .footer { display: none !important; }
    body { background-color: white; }
    .container { padding: 0; margin: 0; width: 100%; }
    .sudoku-board { 
        width: 540px; 
        height: 540px; 
        border: 4px solid #000000; 
        background-color: #000000;
        margin-top: 2rem;
    }
    .sudoku-cell { color: #000000; font-size: 1.8rem; }
    .sudoku-cell.readonly { background-color: #ffffff; }
    .sudoku-cell:nth-child(3n) { border-right: 3px solid #000000; }
    .sudoku-row-3 .sudoku-cell, .sudoku-row-6 .sudoku-cell { border-bottom: 3px solid #000000; }
}