html, body {
  margin: 0;
  height: 200vh; /* PC用スクロール */
  background: rgb(238,243,250);
  transition: background-color 1s ease;
  font-family: serif;
}

/* ===== Text ===== */
.float-text {
  position: fixed;
  top: 3rem;
  left: 3rem;
  max-width: 65ch;
  font-size: 2.2rem;
  line-height: 1.5;
  transition: opacity 0.6s ease, filter 0.6s ease;
}

.studio-name {
  display: block;
  margin-bottom: 3rem;
  opacity: 0.5;
}

/* PC: opacity制御 */
.lang {
  opacity: 0;
  transition: opacity 0.6s ease;
}

.lang.active {
  opacity: 1;
}

/* UI */
.lang-labels {
  margin-top: 4rem;
  font-size: 12px;
  letter-spacing: 0.12em;
}

.lang-labels span {
  cursor: pointer;
  opacity: 0.4;
}

.lang-labels span:hover {
  opacity: 1;
}

@media (max-width: 768px) {

  html, body {
    height: auto;
  }

  .float-text {
    position: fixed;        /* ← PCと同じに戻す */
    top: 1.25rem;
    left: 1.25rem;
    right: 1.25rem;
    max-width: none;
    font-size: 1.4rem;
  }

  .studio-name {
    margin-bottom: 1.5rem;
  }

  /* 🔑 非activeをレイアウトから外す */
  .lang {
    position: absolute;
    opacity: 0;
    pointer-events: none;
  }

  .lang.active {
    position: relative;
    opacity: 1;
    pointer-events: auto;
  }

  .lang-labels {
    margin-top: 1.5rem;
    font-size: 11px;
  }
}