.lesson-card {
    background: var(--card-bg);
    padding: var(--spacing);
    border-radius: var(--radius);
    box-shadow: var(--card-shadow);
    transition: transform var(--transition),
                box-shadow var(--transition);
}

.lesson-card:hover {
    transform: translateY(-5px);
}

.lesson-card h2 {
    margin-bottom: 12px;
    padding-bottom: 6px;
    border-bottom: 3px solid var(--color-primary);
}

.audio-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.audio-list a {
    background: var(--color-primary);
    color: white;
    padding: 6px 10px;
    border-radius: 6px;
    font-size: 0.9rem;
    transition: opacity var(--transition),
                transform 0.15s ease;
}

.audio-list a:hover {
    opacity: 0.85;
    transform: scale(1.05);
}

/* ============================= */
/*   Audio Player Styling        */
/* ============================= */

.audio-item {
    margin-bottom: 15px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.audio-item span {
    font-weight: 600;
    font-size: 0.9rem;
}

audio {
    width: 100%;
    border-radius: 8px;
}

/* ============================= */
/*   Collapsible Lessons         */
/* ============================= */

.lesson-card summary {
    font-weight: 600;
    font-size: 1.1rem;
    cursor: pointer;
    list-style: none;
    padding-bottom: 8px;
    border-bottom: 3px solid var(--color-primary);
    margin-bottom: 12px;
}

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

/* Custom Pfeil */

.lesson-card summary::after {
    content: "▸";
    float: right;
    transition: transform var(--transition);
}

.lesson-card[open] summary::after {
    transform: rotate(90deg);
}

/* ============================= */
/*   Ultra Smooth Accordion      */
/* ============================= */

.lesson-content {
    overflow: hidden;
    height: 0;
    opacity: 0;
    transform: translateY(-8px);
    transition:
        height 0.5s cubic-bezier(0.22, 1, 0.36, 1),
        opacity 0.35s ease,
        transform 0.4s cubic-bezier(0.22, 1, 0.36, 1);
}

.lesson-card[open] .lesson-content {
    opacity: 1;
    transform: translateY(0);
}