:root {
    --primary-green: #3cae71;
    --bg-black: #050505;
    --card-bg: #111;
    --text-white: #ffffff;
    --text-gray: #c6c6c6;
}

main { padding-top: 100px; max-width: 900px; margin: 0 auto; padding-bottom: 60px; padding-left: 20px; padding-right: 20px;}

.page-header { text-align: center; margin-bottom: 60px; }
.page-header h2 { font-size: 2.2rem; color: var(--primary-green); border-bottom: 2px solid #333; display: inline-block; padding-bottom: 10px; }

/* Enhanced Course Card */
.course-card {
    background-color: var(--card-bg);
    border: 1px solid #222;
    border-left: 5px solid var(--primary-green);
    padding: 30px;
    margin-bottom: 40px;
    border-radius: 0 10px 10px 0;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(60, 174, 113, 0.2);
    border-color: #333;
}

.course-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 20px;
}

.course-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-white);
    max-width: 80%;
}

.course-code {
    background: rgba(60, 174, 113, 0.1);
    color: var(--primary-green);
    padding: 5px 10px;
    border-radius: 4px;
    font-weight: bold;
    font-size: 0.9rem;
    border: 1px solid var(--primary-green);
}

.course-desc {
    color: var(--text-gray);
    font-size: 1rem;
    line-height: 1.7;
}

/* Decorative Background */
.course-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: linear-gradient(45deg, transparent 95%, rgba(60,174,113,0.1) 100%);
    pointer-events: none;
}

/* Responsive */
@media (max-width: 768px) {
    .course-header { flex-direction: column; gap: 10px; }
}