body {
  margin: 0;
  padding: 0;
  background-color: #000;
}

dialog:-internal-dialog-in-top-layer::backdrop {
  position: fixed;
  inset: 0px;
  background: rgba(0, 0, 0, 0.5);
}

#player-container {
  width: 100dvw;
  height: calc(100dvh - 8px);
}

#ctrl-panel form p {
  margin-block-start: .6em;
  margin-block-end: .6em;
}

#ctrl-panel form p:first-child {
  margin-block-start: 0;
}

#ctrl-panel form .title {
  font-size: 1.1em;
  font-weight: bold;
}

#ctrl-panel form .title small {
  font-size: .7em;
}

#ctrl-panel form textarea {
  display: block;
  width: 92%;
}

#ctrl-panel form textarea, #ctrl-panel form input {
  margin-bottom: 10px;
  margin-left: 2px;
  font-size: 16px; /* ズーム防止 */
}

#ctrl-panel form #btnArea {
  display: flex;
  justify-content: space-evenly;
}