/* 音質紹介：最大幅1440px */
.sound-feature { background: #fff; color: #404040; }
.sound-inner { width: 100%; max-width: 1440px; margin-inline: auto; padding: 52px 24px 80px; }
.sound-title { margin: 0; text-align: center; font-size: clamp(28px, 3.61vw, 52px); font-weight: 700; line-height: 1.5; }
.sound-lead { margin: 40px auto 0; text-align: center; font-size: 20px; line-height: 2; }
.sound-demo { max-width: 900px; margin: 56px auto 0; }
.sound-visual { position: relative; width: 100%; aspect-ratio: 900 / 800; }
.sound-image-clip { position: absolute; inset: 0; overflow: hidden; }
.sound-image-clip img { display:block; width:100%; height:auto; }
/* 元画像のスピーカー中心(866,610)を図版内の相対位置に変換 */
.sound-waves { position: absolute; left: 66.22222222%; top: 30%; width: 55.55555556%; aspect-ratio: 500 / 460; transform: translate(-50%, -50%); pointer-events: none; }
.sound-waves svg { display: block; width: 100%; height: 100%; overflow: visible; }
.sound-wave { position: absolute; inset: 0; display: block; transform-box: border-box; transform-origin: 50% 50%; opacity: 0; animation: sound-expand 3s linear infinite; }
.sound-wave-1 { animation-delay: 0s; }
.sound-wave-2 { animation-delay: -.75s; }
.sound-wave-3 { animation-delay: -1.5s; }
.sound-wave-4 { animation-delay: -2.25s; }
/* 各波紋は同じHTMLボックスに重ねる。中心は固定し、scaleと透明度のみ変化。 */
@keyframes sound-expand {
  0% { transform: scale(0); opacity: 0; }
  6% { opacity: .9; }
  55% { opacity: .85; }
  80% { opacity: .5; }
  100% { transform: scale(1.55); opacity: 0; }
}
.sound-demo.is-paused .sound-wave { animation-play-state: paused; }
.sound-toggle { display: block; margin: 16px auto 0; padding: 4px 14px; min-height: 44px; border: 1px solid #aaa; border-radius: 4px; background: #fff; color: #404040; font: inherit; font-size: 12px; cursor: pointer; }
.sound-toggle[hidden] { display: none; }
.sound-toggle:focus-visible { outline: 2px solid #003b85; outline-offset: 3px; }
@media (max-width: 767px) {
  .sound-inner { padding: 48px 20px; }
  .sound-title { font-size: 28px; }
  .sound-lead { margin-top: 24px; text-align: left; font-size: 16px; line-height: 1.9; }
  .sound-pc-break { display: none; }
  .sound-demo { margin-top: 32px; }
}
@media (prefers-reduced-motion: reduce) {
  .sound-wave { animation: none; opacity: 0; }
  .sound-wave-2 { transform: scale(1); opacity: .35; }
  .sound-wave-4 { transform: scale(1.3); opacity: .18; }
  .sound-toggle { display: none; }
}

/* 音質紹介：写真と説明 */
.sound-cards {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 40px;
  max-width: 1000px;
  margin: 56px auto 0;
}

.sound-card {
  min-width: 0;
}

.sound-card__image {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  aspect-ratio: 12 / 7;
}

.sound-card__image img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.sound-card__title {
  margin: 30px 0 0;
  color: #404040;
  font-size: 24px;
  font-weight: 700;
  line-height: 1.5;
  text-align: left;
}

.sound-card__text {
  margin: 22px 0 0;
  color: #404040;
  font-size: 16px;
  line-height: 1.9;
  text-align: left;
  overflow-wrap: anywhere;
}

@media (max-width: 767px) {
  .sound-cards {
    grid-template-columns: 1fr;
    gap: 36px;
    margin-top: 32px;
  }

  .sound-card__title {
    margin-top: 20px;
    font-size: 21px;
  }

  .sound-card__text {
    margin-top: 14px;
  }
}