player.css

/**
 * @define audio
 */
:root {
  --audio--color--highlight: #8f098f;
  --audio--color--base: #102027;
  --audio--color--select: #8f098f;
  --audio--color--chapter: #9c9c9c;
  --audio--transtion: 0.2s;
}

.audio,
.audio * {
  box-sizing: border-box;
}

.audio {
  display: flex;
  align-items: center;
}

.audio_sound {
  display: flex;
  flex: 4;
  align-items: center;
}

.audio_volume {
  display: none;
}

.audio_button {
  display: flex;
  align-items: center;
  background: none;
  padding: 0;
  border: 0;
}

.audio_button_icon {
  display: inline-block;
  width: 2.5rem;
  height: 2.5rem;
}

.audio_button_icon--inactive {
  display: none;
}

.audio_button_icon--small {
  width: 1.75rem;
  height: 1.75rem;
}

.audio_button {
  position: relative;
  border: 0;
  flex: none;
  width: auto;
  height: auto;
  background: transparent;
  margin-right: 0.75rem;
  border-radius: 50%;
  padding: 0;
  cursor: pointer;
  transition: var(--audio--transtion) ease-out;
}

.audio_button:hover {
  transform: scale(1.05, 1.05);
}

.audio_button:active {
  transform: scale(0.95, 0.95);
}

.is-playing .audio_button--play .audio_button_icon,
.is-muted .audio_button--volume .audio_button_icon {
  display: none;
}

.is-playing .audio_button--play .audio_button_icon--inactive,
.is-muted .audio_button--volume .audio_button_icon--inactive {
  display: block;
}

.is-playing .audio_button--play .audio_button_icon--inactive {
  display: block;
}

.audio_duration {
  display: inline-block;
  font-size: 0.75rem;
  padding-top: 0.5rem;
}

.audio_chapters {
  position: relative;
  list-style: none;
  margin-top: 0;
  margin-bottom: 0;
  padding-left: 0;
  font-size: 0.75rem;
}

.audio_chapters_chapter {
  position: absolute;
  top: 0;
  padding-left: 1rem;
  margin-top: -0.6rem;
  cursor: pointer;
}

.audio_chapters_chapter::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 0.75rem;
  height: 0.75rem;
  border-radius: 50%;
  background: var(--audio--color--chapter);
  box-shadow: 0 2px 1px rgba(100, 100, 100, 0.3);
  transform: scale(0.75, 0.75);
  transition: var(--audio--transtion) ease-out;
}

.audio_chapters_chapter:hover::before {
  transform: scale(1, 1);
}

.audio_chapters_chapter_title {
  position: absolute;
  top: -1.5rem;
  left: 50%;
  transform: translateX(-50%);
  opacity: 0;
  white-space: nowrap;
  transition: var(--audio--transtion) ease-out;
  background: #fff;
  border-radius: 0.75rem;
  padding: 0.25rem 0.5rem;
  box-shadow: 0 2px 1px rgba(100, 100, 100, 0.3);
}

.audio_chapters_chapter:hover .audio_chapters_chapter_title {
  opacity: 1;
}

.audio_progress {
  padding-top: 1rem;
  padding-bottom: 1rem;
}

.audio_progress_bar {
  position: relative;
  width: 100%;
  height: 0.5rem;
  background-color: rgba(255, 255, 255, 0.5);
  border-radius: 10px;
  margin-right: 1.5rem;
}

.audio_progress_inner {
  position: relative;
  width: 0;
  height: 0.5rem;
  background-color: var(--audio--color--highlight);
  border-radius: 10px;
}

.audio_progress_preloaded {
  position: absolute;
  top: 0;
  left: 0;
  width: 0;
  height: 0.5rem;
  border-radius: 10px;
  background-color: var(--audio--color--base);
  opacity: 0.15;
  transition: width 0.15s;
}

.audio_progress_button {
  position: absolute;
  z-index: 1;
  top: 50%;
  right: 0;
  width: 1rem;
  height: 1rem;
  border-radius: 50%;
  background-color: #fff;
  transform: translate(50%, -50%);
  box-shadow: 0 2px 1px rgba(100, 100, 100, 0.3);
  transition: var(--audio--transtion);
  border: 0;
}

.audio_progress:hover .audio_progress_button {
  width: 1.25rem;
  height: 1.25rem;
  cursor: pointer;
}

.audio_speed {
  font-size: 0.875rem;
}

@media (min-width: 40rem) {
  .audio_progress {
    padding-top: 2rem;
    padding-bottom: 2rem;
  }

  .audio_progress_bar {
    margin-right: 1rem;
  }

  .audio_volume {
    display: flex;
    flex: 1;
    align-items: center;
  }
}