#music-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.piano-card {
    background: #222226;
    border: 1px solid #2D2D31;
    border-radius: 10px;
    overflow: hidden;
}

.piano-card summary {
    padding: 18px 20px;
    color: #F7F5F0;
    font-size: 18px;
    font-weight: 500;
    cursor: pointer;
    list-style: none;
}

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

.piano-card summary::after {
    content: "+";
    float: right;
    color: #B89B5E;
    font-size: 22px;
}

.piano-card[open] summary::after {
    content: "−";
}

.piano-card summary:hover {
    color: #B89B5E;
}

.piano-video {
    padding: 0 20px 20px 20px;
}

.piano-video video {
    display: block;
    width: 100%;
    max-width: 800px;
    height: auto;
    margin: 0 auto;
    border-radius: 6px;
}