html, body {
    width: 100%;
    height: 100%;
    margin: 0;
    overflow: hidden;
    background: #000;
    color: #fff;
    font-family: Arial, sans-serif;
}

#app {
    position: relative;
    box-sizing: border-box;
    width: 1280px;
    height: 720px;
    padding: 48px 64px;
}

header {
    position: relative;
}

h1 {
    margin: 0 0 12px;
    font-size: 44px;
}

#hint {
    margin: 0 0 28px;
    font-size: 22px;
    color: #bbb;
}

#menu {
    display: grid;
    grid-template-columns: repeat(4, 240px);
    gap: 18px;
}

.item {
    min-height: 92px;
    font-size: 26px;
    border: 4px solid transparent;
    background: #1f1f1f;
    color: #fff;
}

.item.focus {
    border-color: #afca05;
    background: #444;
}

#info {
    margin-top: 28px;
    font-size: 28px;
    min-height: 40px;
}
#menu.hidden,
.hidden {
    display: none;
}

#playerView {
    margin-top: 24px;
}

#playerBox {
    width: 960px;
    height: 540px;
    background: #111;
    border: 4px solid #333;
}

#iframePlayer,
#videoPlayer {
    width: 100%;
    height: 100%;
    background: #000;
}

#playerHint {
    margin-top: 16px;
    font-size: 22px;
    color: #bbb;
}