:root {
    --primary: #0a0e27;
    --secondary: #1a1f3a;
    --accent: #00ff88;
    --accent-dark: #00cc6a;
    --danger: #ff3366;
    --text: #e0e0e0;
    --text-dark: #8892b0;
    --card-bg: rgba(26, 31, 58, 0.95);
}

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

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

/* Header et Navigation */
.header {
    background: rgba(10, 14, 39, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    border-bottom: 1px solid rgba(0, 255, 136, 0.3);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent);
    text-decoration: none;
}

.logo:hover {
    color: var(--accent-dark);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    flex-wrap: wrap;
}

.nav-menu a {
    color: var(--text);
    text-decoration: none;
    transition: color 0.3s;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--accent);
}

/* Main Content */
.main-content {
    max-width: 1200px;
    margin: 80px auto 0;
    padding: 2rem;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 4rem 2rem;
    background: linear-gradient(135deg, rgba(0, 255, 136, 0.1), rgba(0, 0, 0, 0.3));
    border-radius: 20px;
    margin-bottom: 3rem;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--accent), #fff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-dark);
}

/* Courses Grid */
.section-title {
    font-size: 2rem;
    margin-bottom: 2rem;
    border-left: 4px solid var(--accent);
    padding-left: 1rem;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.course-card {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 1.5rem;
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid rgba(0, 255, 136, 0.2);
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 255, 136, 0.2);
    border-color: var(--accent);
}

.course-card h3 {
    color: var(--accent);
    margin-bottom: 1rem;
}

.course-meta {
    display: flex;
    gap: 1rem;
    margin: 1rem 0;
    font-size: 0.9rem;
    color: var(--text-dark);
}

.course-level {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: bold;
}

.level-debutant { background: #00ff8844; color: #00ff88; }
.level-intermediaire { background: #ffaa0044; color: #ffaa00; }
.level-avance { background: #ff336644; color: #ff3366; }

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: bold;
    transition: all 0.3s;
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    background: var(--accent-dark);
    transform: translateY(-2px);
}

.btn-outline {
    border: 2px solid var(--accent);
    color: var(--accent);
    background: transparent;
}

.btn-outline:hover {
    background: var(--accent);
    color: var(--primary);
}

/* Course Page */
.course-header {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
}

.course-content {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 2rem;
}

.course-content h2 {
    color: var(--accent);
    margin: 1.5rem 0 1rem;
}

.course-content h3 {
    color: var(--text);
    margin: 1rem 0 0.5rem;
}

.course-content ul,
.course-content ol {
    margin: 1rem 0 1rem 2rem;
}

.course-content li {
    margin: 0.5rem 0;
}

.course-content pre {
    background: var(--primary);
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1rem 0;
}

.course-content code {
    font-family: 'Courier New', monospace;
    color: var(--accent);
}

/* Quiz Section */
.quiz-section {
    margin-top: 2rem;
    padding: 2rem;
    background: var(--card-bg);
    border-radius: 15px;
}

.question {
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: rgba(0, 0, 0, 0.3);
    border-radius: 10px;
}

.options {
    margin: 1rem 0 0 1rem;
}

.options label {
    display: block;
    margin: 0.5rem 0;
    cursor: pointer;
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem;
    background: var(--primary);
    margin-top: 3rem;
    border-top: 1px solid rgba(0, 255, 136, 0.3);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-menu {
        justify-content: center;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .courses-grid {
        grid-template-columns: 1fr;
    }

    .main-content {
        padding: 1rem;
    }
}

/* Progress Bar */
.progress-container {
    background: var(--secondary);
    border-radius: 10px;
    height: 10px;
    margin: 1rem 0;
    overflow: hidden;
}

.progress-bar {
    background: var(--accent);
    height: 100%;
    transition: width 0.3s;
}

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

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