/* Reset and Base Styles */

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f8f9fa;
}


/* Header and Navigation */

header {
    background: #2c3e50;
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
}

.logo i {
    color: #3498db;
    margin-right: 10px;
}

.search-bar {
    display: flex;
    background: white;
    border-radius: 25px;
    overflow: hidden;
}

.search-bar input {
    padding: 8px 15px;
    border: none;
    width: 300px;
    outline: none;
}

.search-bar button {
    padding: 8px 15px;
    background: #3498db;
    color: white;
    border: none;
    cursor: pointer;
}


/* Hero Section */

.hero {
    background: linear-gradient(135deg, #3498db, #2c3e50);
    color: white;
    text-align: center;
    padding: 60px 20px;
    margin-bottom: 40px;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 15px;
}

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


/* Category Grid */

.categories {
    max-width: 1200px;
    margin: 0 auto 40px;
    padding: 0 20px;
}

.categories h2 {
    margin-bottom: 30px;
    font-size: 2rem;
    color: #2c3e50;
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 25px;
}

.category-card {
    background: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    text-decoration: none;
    color: #333;
    transition: transform 0.3s, box-shadow 0.3s;
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.12);
}

.category-card i {
    font-size: 2.5rem;
    color: #3498db;
    margin-bottom: 15px;
}

.category-card h3 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.category-card p {
    color: #7f8c8d;
    font-size: 0.9rem;
}


/* Course Grid */

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

.course-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s;
}

.course-card:hover {
    transform: translateY(-3px);
}

.course-card a {
    text-decoration: none;
    color: #333;
    display: block;
    padding: 25px;
}

.course-card h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: #2c3e50;
}

.course-card p {
    color: #7f8c8d;
    font-size: 0.95rem;
}

.level {
    display: inline-block;
    padding: 3px 12px;
    border-radius: 15px;
    font-size: 0.8rem;
    margin-top: 10px;
}

.level.beginner {
    background: #27ae60;
    color: white;
}

.level.intermediate {
    background: #f39c12;
    color: white;
}

.level.advanced {
    background: #e74c3c;
    color: white;
}


/* Course Detail Page */

.course-container {
    max-width: 1200px;
    margin: 30px auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 30px;
}

.course-header {
    grid-column: 1 / -1;
    background: white;
    padding: 30px;
    border-radius: 10px;
    margin-bottom: 20px;
}

.course-meta {
    display: flex;
    gap: 20px;
    margin-top: 15px;
    flex-wrap: wrap;
}

.sidebar {
    background: white;
    border-radius: 10px;
    padding: 20px;
}

.sidebar h3 {
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #3498db;
}

.chapter {
    margin-bottom: 20px;
}

.chapter h4 {
    color: #2c3e50;
    margin-bottom: 8px;
}

.module {
    margin-left: 15px;
    margin-bottom: 12px;
}

.module h5 {
    color: #3498db;
    font-size: 0.95rem;
    margin-bottom: 5px;
}

.module ul {
    list-style: none;
    padding-left: 10px;
}

.module ul li {
    padding: 5px 0;
    border-bottom: 1px solid #f0f0f0;
}

.module ul li a {
    text-decoration: none;
    color: #333;
    display: flex;
    align-items: center;
    gap: 8px;
}

.module ul li a:hover {
    color: #3498db;
}

.duration {
    font-size: 0.8rem;
    color: #7f8c8d;
    margin-left: auto;
}


/* Responsive */

@media (max-width: 768px) {
    .course-container {
        grid-template-columns: 1fr;
    }
    .search-bar input {
        width: 150px;
    }
    .category-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
}