.courses {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.course {
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 1.5rem;
    background-color: #fff;
}

.course h3 {
    margin-top: 0;
    margin-bottom: 0.5rem;
}

.course-intro {
    margin-bottom: 1rem;
    color: #444;
}

.course-details summary {
    cursor: pointer;
    font-weight: 600;
    color: #0080ff;
    list-style: none;
}

.course-details summary::-webkit-details-marker {
    display: none;
}

.course-details summary::after {
    content: " ▾";
}

.course-details[open] summary::after {
    content: " ▴";
}

.course-info {
    margin-top: 1rem;
    padding-left: 1.2rem;
}

.course-info li {
    margin-bottom: 0.4rem;
}