html, body {
  width: 100%;
  min-width: 0;
  height: 100%;
  overflow: hidden;
  overscroll-behavior: none;
}

.old-header {
  position: fixed;
  top: 12px;
  left: 16px;
  z-index: 10000;
  display: flex;
  align-items: center;
  gap: 18px;
  color: #fff;
  font-family: "DM Sans", "Noto Sans JP", sans-serif;
}

.old-home {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 42px;
  padding: 0 15px;
  border: 1px solid rgba(255, 255, 255, .24);
  border-radius: 999px;
  color: #fff;
  background: rgba(17, 17, 15, .74);
  text-decoration: none;
  box-shadow: 0 8px 28px rgba(0, 0, 0, .2);
  backdrop-filter: blur(10px);
}

.old-header p { display: grid; gap: 1px; margin: 0; text-shadow: 0 1px 5px #000; }
.old-header strong { font-size: 11px; letter-spacing: .15em; }
.old-header p span { font-size: 8px; letter-spacing: .18em; }

#button-container { position: fixed; inset: 0; overflow: hidden; }
.floating-button { touch-action: manipulation; }
.floating-button.show-text p { display: block; }

.buttons-container {
  position: fixed;
  bottom: 14px;
  left: 14px;
  z-index: 10000;
  display: block;
  padding: 5px;
  border-radius: 999px;
  background: rgba(21, 21, 21, .88);
  box-shadow: 0 8px 28px rgba(0, 0, 0, .28);
}
.buttons-container ul { display: flex; margin: 0; padding: 0; list-style: none; }
.buttons-container li { display: grid; place-items: center; width: 38px; height: 38px; border-radius: 50%; cursor: pointer; }
.buttons-container li.active { background: rgba(255, 255, 255, .12); }
.buttons-container a { color: #999; }
.buttons-container .active-text { color: #d9ff64; }

.copyright {
  position: fixed;
  left: 50%;
  bottom: 12px;
  z-index: 9999;
  transform: translateX(-50%);
  color: #111;
  font-size: 11px;
  text-decoration: none;
  text-shadow: 0 1px 4px #fff;
}

@media (max-width: 600px) {
  .old-header { top: 8px; left: 8px; }
  .old-header p { display: none; }
  .old-home { min-height: 38px; padding: 0 12px; font-size: 12px; }
  .floating-button { width: 82px; height: 82px; border-radius: 16px; padding: 7px; }
  .floating-button img { border-radius: 11px; }
  .floating-button p { font-size: 9px; }
  .buttons-container { bottom: 8px; left: 8px; transform: scale(.86); transform-origin: bottom left; }
  .copyright { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  body { background-attachment: initial; }
}