body {
    background-color: darkolivegreen;
    margin: 0;
    padding: 0;
    overflow-x: hidden;
}

/* Keep the piano and the traditional staffs inside the 1920 x 1080 board. */
midi-keyboard {
    position: absolute;
    top: 582px;
    left: 50%;
    z-index: 20;
    width: 1880px;
    max-width: calc(100vw - 40px);
    transform: translateX(-50%);
    outline: 2px solid red;
    background-color: rgba(0, 0, 0, 0.7);
}

#staffs-container {
    position: absolute;
    top: 740px;
    left: 50%;
    z-index: 20;
    width: 1700px;
    max-width: calc(100vw - 220px);
    height: 480px;
    overflow-y: auto;
    transform: translateX(-50%);
}

/* Toolbar groups: space around and between their buttons (see src/toolbar.js). */
tools-bar-group::part(content) {
    gap: 6px;
    padding: 0 6px;
}