:root {
    --primary-color: #2196F3;
    --secondary-color: #21CBF3;
}
.course-page-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 50px 0;
    text-align: center;
    border-bottom-left-radius: 30px;
    border-bottom-right-radius: 30px;
}
.course-page-header h1 {
    font-size: 2.8rem;
    margin: 0;
}
.course-page-body {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    padding: 40px 0;
    align-items: flex-start;
}
.course-sidebar {
    background: #fff;
    padding: 1.5rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    position: sticky;
    top: 90px; /* 70px header height + 20px space */
}
.course-sidebar img {
    border-radius: 10px;
    margin-bottom: 1rem;
}
.course-sidebar .price {
    font-size: 2rem;
    font-weight: 900;
    color: var(--primary-color);
    display: block;
    text-align: center;
    margin-bottom: 1rem;
}
.course-sidebar .btn {
    width: 100%;
    margin-bottom: 0.5rem;
    padding: 15px;
    font-size: 1.1rem;
}
.course-main-content h2 {
    font-size: 1.8rem;
    border-bottom: 3px solid var(--primary-color);
    padding-bottom: 10px;
    display: inline-block;
    margin-bottom: 1.5rem;
}
.course-curriculum ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
}
.course-curriculum li {
    padding: 15px;
    border-bottom: 1px solid #eee;
    font-weight: 600;
    transition: background-color 0.3s;
}
.course-curriculum li:hover {
    background-color: #f8f9fa;
}
.course-curriculum li i {
    color: var(--primary-color);
    margin-left: 10px;
}
@media (max-width: 992px) {
    .course-page-body {
        grid-template-columns: 1fr;
    }
    .course-sidebar {
        position: static; /* Remove sticky on smaller screens */
        margin-top: 2rem;
    }
}