/* ===== GOOGLE FONTS ===== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* ===== CSS VARIABLES ===== */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --secondary: #ec489a;
    --dark: #0f172a;
    --gray: #64748b;
    --light: #f8fafc;
    --white: #ffffff;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
}

/* ===== BASE STYLES ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    color: var(--dark);
    background: var(--light);
    line-height: 1.6;
}

/* ===== NAVIGATION ===== */
.navbar {
    background: var(--white);
    box-shadow: var(--shadow-sm);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-link {
    font-weight: 500;
    color: var(--gray);
    transition: color 0.3s;
}

.nav-link:hover {
    color: var(--primary);
}

/* ===== HERO SECTION ===== */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--white);
    padding: 100px 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="rgba(255,255,255,0.1)" fill-opacity="1" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,122.7C672,117,768,139,864,154.7C960,171,1056,181,1152,170.7C1248,160,1344,128,1392,112L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
    background-size: cover;
    opacity: 0.1;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    animation: fadeInUp 1s ease 0.2s both;
}

/* ===== COURSE CARDS ===== */
.course-card {
    background: var(--white);
    border-radius: 1rem;
    overflow: hidden;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
    cursor: pointer;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.course-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.course-card .card-body {
    padding: 1.5rem;
}

.course-card .card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--dark);
}

.course-card .card-text {
    color: var(--gray);
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.course-price {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 1rem;
}

.course-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.85rem;
    color: var(--gray);
}

.badge-level {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 2rem;
    font-size: 0.75rem;
    font-weight: 600;
}

/* ===== BUTTONS ===== */
.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    transition: all 0.3s;
    cursor: pointer;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border: none;
    color: var(--white);
}

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

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

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

/* ===== DASHBOARD ===== */
.dashboard-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 1rem;
    text-align: center;
    box-shadow: var(--shadow-md);
}

.stat-card h3 {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

/* ===== ANIMATIONS ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .dashboard-stats {
        grid-template-columns: 1fr;
    }
}

/* ===== LOADING SPINNER ===== */
.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--light);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}