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

body {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

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

.header {
    text-align: center;
    background: white;
    padding: 40px 20px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    margin-bottom: 30px;
}

.header h1 {
    color: #4c00b0;
    font-size: clamp(24px, 5vw, 36px);
    margin-bottom: 10px;
    font-weight: 700;
}

.subtitle {
    color: #666;
    font-size: clamp(14px, 3vw, 18px);
    font-weight: 600;
}

.search-container {
    margin-bottom: 20px;
}

.search-input {
    width: 100%;
    padding: 18px 24px;
    font-size: 16px;
    border: none;
    border-radius: 50px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    font-family: 'Poppins', sans-serif;
    transition: all 0.3s ease;
}

.search-input:focus {
    outline: none;
    box-shadow: 0 5px 30px rgba(76, 0, 176, 0.3);
    transform: translateY(-2px);
}

.filter-container {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
    justify-content: center;
}

.filter-btn {
    padding: 12px 24px;
    border: none;
    border-radius: 50px;
    background: white;
    color: #4c00b0;
    font-family: 'Poppins', sans-serif;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
}

.filter-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(76, 0, 176, 0.2);
}

.filter-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: white;
    padding: 20px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.stat-number {
    display: block;
    font-size: 32px;
    font-weight: 700;
    color: #4c00b0;
    margin-bottom: 5px;
}

.stat-label {
    display: block;
    font-size: 14px;
    color: #666;
    font-weight: 600;
}

.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.course-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    animation: fadeIn 0.5s ease;
}

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

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(76, 0, 176, 0.2);
}

.course-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 20px;
    color: white;
}

.course-category {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 8px;
}

.course-number {
    font-size: 14px;
    opacity: 0.9;
    font-weight: 600;
}

.course-title {
    font-size: 18px;
    font-weight: 700;
    margin-top: 5px;
}

.course-body {
    padding: 20px;
}

.video-link {
    display: inline-block;
    width: 100%;
    padding: 15px 25px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    text-align: center;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.video-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

.no-results {
    text-align: center;
    padding: 60px 20px;
    background: white;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.no-results p {
    font-size: 18px;
    color: #666;
}

.footer {
    text-align: center;
    margin-top: 40px;
    padding: 30px 20px;
    background: white;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.footer-text {
    font-size: 20px;
    font-weight: bold;
    background: linear-gradient(to right, #8e2de2, #4a00e0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    .header {
        padding: 30px 15px;
    }

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

    .stats-container {
        grid-template-columns: repeat(2, 1fr);
    }

    .filter-container {
        gap: 8px;
    }

    .filter-btn {
        padding: 10px 16px;
        font-size: 13px;
    }
}