:root {
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --bg-card: #0f3460;
    --accent-primary: #00d9ff;
    --accent-secondary: #7b2cbf;
    --success: #06ffa5;
    --warning: #ffbe0b;
    --danger: #ff006e;
    --text-primary: #ffffff;
    --text-secondary: #b8b8d1;
    --border-radius: 20px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

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

/* Navigation */
.navbar {
    background: var(--bg-secondary);
    padding: 15px 0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 28px;
    font-weight: bold;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 30px;
    align-items: center;
    list-style: none;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
    padding: 8px 16px;
    border-radius: 10px;
}

.nav-links a:hover {
    color: var(--accent-primary);
    background: rgba(0, 217, 255, 0.1);
}

.user-stats {
    display: flex;
    gap: 20px;
    align-items: center;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 8px;
    background: var(--bg-card);
    padding: 8px 15px;
    border-radius: 15px;
    font-weight: 600;
}

.stat-item span {
    font-size: 20px;
}

/* Boutons */
.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 15px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    display: inline-block;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 217, 255, 0.4);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--bg-secondary);
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-success {
    background: var(--success);
    color: var(--bg-primary);
}

/* Cards */
.card {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 25px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0, 217, 255, 0.2);
}

/* Grille */
.grid {
    display: grid;
    gap: 25px;
}

.grid-2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }

/* Formulaires */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 12px 20px;
    background: var(--bg-secondary);
    border: 2px solid transparent;
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 16px;
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(0, 217, 255, 0.1);
}

select.form-control {
    cursor: pointer;
}

textarea.form-control {
    resize: vertical;
    min-height: 100px;
}

/* Progress Bar */
.progress-bar {
    width: 100%;
    height: 12px;
    background: var(--bg-secondary);
    border-radius: 10px;
    overflow: hidden;
    position: relative;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 10px;
    transition: width 0.5s ease;
}

/* Badges */
.badge {
    display: inline-block;
    padding: 6px 14px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
}

.badge-success { background: var(--success); color: var(--bg-primary); }
.badge-warning { background: var(--warning); color: var(--bg-primary); }
.badge-danger { background: var(--danger); color: white; }
.badge-info { background: var(--accent-primary); color: var(--bg-primary); }

/* Alertes */
.alert {
    padding: 15px 20px;
    border-radius: 12px;
    margin-bottom: 20px;
}

.alert-success {
    background: rgba(6, 255, 165, 0.1);
    border-left: 4px solid var(--success);
    color: var(--success);
}

.alert-error {
    background: rgba(255, 0, 110, 0.1);
    border-left: 4px solid var(--danger);
    color: var(--danger);
}

/* Langue Card */
.language-card {
    position: relative;
    overflow: hidden;
}

.language-card .flag {
    font-size: 60px;
    margin-bottom: 15px;
}

.language-card h3 {
    margin-bottom: 10px;
}

.language-card .level-badge {
    position: absolute;
    top: 20px;
    right: 20px;
    background: var(--accent-primary);
    color: var(--bg-primary);
    padding: 8px 15px;
    border-radius: 10px;
    font-weight: bold;
}

/* Lesson Card */
.lesson-card {
    display: flex;
    align-items: center;
    gap: 20px;
    background: var(--bg-card);
    padding: 20px;
    border-radius: 15px;
    cursor: pointer;
    position: relative;
}

.lesson-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    flex-shrink: 0;
}

.lesson-info {
    flex: 1;
}

.lesson-card h4 {
    margin-bottom: 5px;
}

.lesson-stars {
    color: var(--warning);
}

/* Question Container */
.question-container {
    max-width: 800px;
    margin: 50px auto;
}

.question-card {
    background: var(--bg-card);
    border-radius: 20px;
    padding: 40px;
    min-height: 400px;
}

.question-header {
    text-align: center;
    margin-bottom: 30px;
}

.question-text {
    font-size: 24px;
    margin-bottom: 30px;
    text-align: center;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    margin-bottom: 30px;
}

.option-btn {
    padding: 20px;
    background: var(--bg-secondary);
    border: 3px solid transparent;
    border-radius: 15px;
    cursor: pointer;
    transition: var(--transition);
    font-size: 18px;
    color: var(--text-primary);
}

.option-btn:hover {
    border-color: var(--accent-primary);
    background: var(--bg-card);
}

.option-btn.correct {
    border-color: var(--success);
    background: rgba(6, 255, 165, 0.1);
}

.option-btn.incorrect {
    border-color: var(--danger);
    background: rgba(255, 0, 110, 0.1);
}

.answer-input {
    width: 100%;
    padding: 20px;
    font-size: 20px;
    text-align: center;
}

/* Table */
.table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-card);
    border-radius: 15px;
    overflow: hidden;
}

.table th,
.table td {
    padding: 15px;
    text-align: left;
}

.table th {
    background: var(--bg-secondary);
    font-weight: 600;
}

.table tr:hover {
    background: rgba(0, 217, 255, 0.05);
}

/* Leaderboard */
.leaderboard-item {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 20px;
    background: var(--bg-card);
    border-radius: 15px;
    margin-bottom: 15px;
}

.rank {
    font-size: 28px;
    font-weight: bold;
    min-width: 50px;
    text-align: center;
}

.rank.top-1 { color: #FFD700; }
.rank.top-2 { color: #C0C0C0; }
.rank.top-3 { color: #CD7F32; }

.user-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

/* Responsive */
@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
        gap: 15px;
    }
    
    .nav-links {
        flex-direction: column;
        gap: 10px;
    }
    
    .user-stats {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .options-grid {
        grid-template-columns: 1fr;
    }
    
    .grid-2, .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }
}

/* Animations */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: slideIn 0.5s ease;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    z-index: 2000;
    justify-content: center;
    align-items: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--bg-card);
    padding: 40px;
    border-radius: 20px;
    max-width: 500px;
    width: 90%;
    text-align: center;
}

.modal-content h2 {
    margin-bottom: 20px;
}