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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f7fa;
}

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

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px 0;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
}

.campaign-info {
    background: white;
    padding: 40px 0;
    margin: 30px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.campaign-period {
    text-align: center;
}

.campaign-period h2 {
    font-size: 2rem;
    color: #333;
    margin-bottom: 20px;
}

.period-text {
    font-size: 1.3rem;
    color: #e74c3c;
    font-weight: 600;
    margin-bottom: 20px;
}

.countdown {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.countdown-item {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    min-width: 100px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.countdown-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: #667eea;
    display: block;
}

.countdown-label {
    font-size: 0.9rem;
    color: #666;
    text-transform: uppercase;
}

.courses {
    padding: 40px 0;
}

.courses h2 {
    text-align: center;
    font-size: 2rem;
    color: #333;
    margin-bottom: 40px;
}

.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
}

.course-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    display: flex;
    flex-direction: column;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.15);
}

.course-thumbnail {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
}

.course-content {
    padding: 25px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: #667eea;
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
    z-index: 1;
}

.free-badge {
    background: #e74c3c;
}

.course-card.free {
    border: 2px solid #e74c3c;
}

.course-card h3 {
    font-size: 1.2rem;
    margin-bottom: 15px;
    color: #333;
    line-height: 1.4;
    flex-grow: 1;
}

.price {
    font-size: 1.8rem;
    font-weight: 700;
    color: #e74c3c;
    margin-bottom: 15px;
}

.original-price {
    font-size: 0.9rem;
    color: #666;
    font-weight: normal;
}

.btn {
    display: inline-block;
    background: #667eea;
    color: white;
    padding: 12px 30px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: background 0.3s ease;
    text-align: center;
    width: 100%;
}

.btn:hover {
    background: #5a67d8;
}

.btn-free {
    background: #e74c3c;
}

.btn-free:hover {
    background: #c0392b;
}

footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 20px 0;
    margin-top: 60px;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .period-text {
        font-size: 1.1rem;
    }
    
    .countdown-value {
        font-size: 2rem;
    }
    
    .course-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .course-card h3 {
        font-size: 1.1rem;
    }
    
    .course-thumbnail {
        height: 150px;
    }
}