* { box-sizing: border-box; }

html, body { width: 100%; min-width: 320px; min-height: 100%; margin: 0; }

body {
  min-height: 100vh;
  overflow: hidden;
  background: #083e89;
  font-family: "Microsoft YaHei", sans-serif;
}

.cover {
  position: relative;
  min-height: 100svh;
  overflow: hidden;
  isolation: isolate;
}

.sky {
  position: absolute;
  z-index: 0;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  image-rendering: pixelated;
}

.cloud-layer { position: absolute; z-index: 1; inset: 0; overflow: hidden; pointer-events: none; }

.cloud {
  position: absolute;
  width: var(--cloud-width);
  height: auto;
  image-rendering: pixelated;
  animation: cloud-drift var(--cloud-duration) linear infinite alternate;
  will-change: transform;
}

.cloud-one { --cloud-width: min(20vw, 250px); --cloud-duration: 8s; top: 39%; left: -3%; --cloud-drift: 108px; }
.cloud-two { --cloud-width: min(16vw, 210px); --cloud-duration: 10s; top: 40%; right: -4%; --cloud-drift: 86px; }
.cloud-three { --cloud-width: min(12vw, 160px); --cloud-duration: 7s; top: 55%; left: 24%; --cloud-drift: 72px; }
.cloud-four { --cloud-width: min(23vw, 300px); --cloud-duration: 12s; top: 51%; right: 19%; --cloud-drift: 118px; }
.cloud-five { --cloud-width: min(14vw, 180px); --cloud-duration: 9s; top: 62%; left: 4%; --cloud-drift: 82px; }

.music-toggle {
  position: absolute;
  z-index: 5;
  top: clamp(12px, 2.4vh, 28px);
  left: clamp(70px, 5vw, 94px);
  width: clamp(23px, 2.2vw, 34px);
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
  line-height: 0;
}

.music-toggle img { display: block; width: 100%; height: auto; image-rendering: pixelated; }
.music-toggle.is-on { filter: brightness(1.35); }

.cover[data-cloud-speed="slow"] .cloud { animation-duration: calc(var(--cloud-duration) * 1.55); }
.cover[data-cloud-speed="fast"] .cloud { animation-duration: calc(var(--cloud-duration) * .68); }
.cover.clouds-paused .cloud { animation-play-state: paused; }

.cover-title {
  position: absolute;
  z-index: 3;
  top: clamp(18px, 6vh, 70px);
  left: 50%;
  width: min(76vw, 1010px);
  margin: 0;
  transform: translateX(-50%);
}

.cover-title img { display: block; width: 100%; height: auto; image-rendering: pixelated; }

.menu {
  position: absolute;
  z-index: 4;
  bottom: clamp(18px, 5vh, 62px);
  left: 50%;
  display: grid;
  grid-template-columns: repeat(4, minmax(110px, 186px));
  gap: clamp(14px, 2vw, 30px);
  width: min(78vw, 840px);
  transform: translateX(-50%);
}

.menu-item {
  position: relative;
  display: block;
  width: 100%;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
  line-height: 0;
  text-decoration: none;
}

.menu-item img { display: block; width: 100%; height: auto; image-rendering: pixelated; pointer-events: none; }

.save-toast {
  position: absolute;
  z-index: 8;
  top: 50%;
  left: 50%;
  display: grid;
  gap: 7px;
  min-width: min(78vw, 320px);
  padding: 22px 30px;
  border: 5px solid #6c2d13;
  outline: 3px solid #e9a14c;
  background: #ffe0a0;
  color: #6c2d13;
  text-align: center;
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, -42%) scale(.92);
  transition: opacity 180ms ease, transform 180ms ease;
}

.save-toast strong { font-size: 22px; }
.save-toast span { font-size: 14px; }
.save-toast.is-visible { opacity: 1; transform: translate(-50%, -50%) scale(1); }

.settings-panel {
  position: absolute;
  z-index: 9;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 24px;
  background: rgb(2 16 50 / 58%);
  opacity: 0;
  pointer-events: none;
  transition: opacity 180ms ease;
}

.settings-panel.is-open { opacity: 1; pointer-events: auto; }
.settings-card {
  position: relative;
  width: min(90vw, 410px);
  padding: 30px;
  border: 7px solid #693015;
  outline: 4px solid #e6a151;
  background: #ffdda0;
  color: #6b3016;
  box-shadow: 0 12px 0 rgb(48 19 8 / 45%);
  transform: translateY(12px) scale(.96);
  transition: transform 180ms ease;
}

.settings-panel.is-open .settings-card { transform: translateY(0) scale(1); }
.settings-card h2 { margin: 0 0 20px; font-size: 24px; text-align: center; }
.setting-row { display: flex; align-items: center; justify-content: space-between; gap: 18px; padding: 12px 0; border-top: 2px solid #d38d42; font-size: 16px; }
.setting-row input { width: 19px; height: 19px; accent-color: #b9562c; }
.setting-row select { min-width: 112px; padding: 7px 9px; border: 3px solid #8a421c; background: #ffe9b7; color: #693015; font: inherit; }
.settings-close { position: absolute; top: 9px; right: 11px; border: 0; background: transparent; color: #8a421c; font-size: 28px; line-height: 1; cursor: pointer; }
.settings-done { display: block; width: 100%; margin-top: 22px; padding: 10px; border: 4px solid #743318; background: #e59a45; color: #55220f; font: inherit; font-weight: 700; cursor: pointer; }

@keyframes cloud-drift {
  from { transform: translateX(calc(var(--cloud-drift) * -1)); }
  to { transform: translateX(var(--cloud-drift)); }
}

@media (max-width: 760px) {
  .cover-title { top: 5vh; width: min(94vw, 680px); }
  .menu { bottom: 18px; grid-template-columns: repeat(2, minmax(120px, 1fr)); gap: 10px; width: min(78vw, 470px); }
  .cloud-one { top: 36%; }
  .cloud-two { top: 37%; }
  .cloud-three { top: 57%; left: 17%; }
  .cloud-four { top: 55%; right: 3%; }
  .cloud-five { display: none; }
}