:root {
  --bg: #0a0c10;
  --text: #e8eef2;
  --mute: rgba(232, 238, 242, 0.55);
  --soft: rgba(232, 238, 242, 0.38);
  --box: #11151c;
  --box-border: rgba(255, 255, 255, 0.08);
  --box-hover: #171c25;
  --font: "Noto Sans SC", system-ui, -apple-system, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  overflow-x: hidden;
}

body {
  min-height: 100vh;
  min-height: 100dvh;
}

.stage {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
}

/* 16:9 homepage hero — cover full viewport */
.bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center center;
  filter: saturate(1.05) brightness(0.96) contrast(1.04);
  pointer-events: none;
  user-select: none;
  -webkit-user-drag: none;
}

/* lighter over lake so ripples stay visible */
.veil {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(
    180deg,
    rgba(10, 12, 16, 0.28) 0%,
    rgba(10, 12, 16, 0.08) 28%,
    rgba(10, 12, 16, 0.18) 55%,
    rgba(10, 12, 16, 0.55) 100%
  );
  pointer-events: none;
}

/* Snow + lake ripples layer */
.snow,
.fx {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 2;
  opacity: 1;
}

.shell {
  position: relative;
  z-index: 3;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 22px 20px 40px;
}

.hero {
  margin-top: clamp(12vh, 16vh, 18vh);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  opacity: 0;
  animation: in 0.9s ease 0.12s forwards;
}

/* 图标 + 标题：同一行，图标在左 */
.brand {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  gap: clamp(12px, 2.5vw, 20px);
  margin-bottom: 18px;
}

.logo {
  width: clamp(52px, 12vw, 72px);
  height: clamp(52px, 12vw, 72px);
  object-fit: contain;
  display: block;
  flex-shrink: 0;
  background: transparent !important;
  border: none;
  border-radius: 0;
  box-shadow: none;
  /* only soft drop shadow; no plate */
  filter: drop-shadow(0 8px 20px rgba(0, 0, 0, 0.4));
  user-select: none;
  -webkit-user-drag: none;
}

.title {
  margin: 0;
  font-size: clamp(40px, 9vw, 56px);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-indent: 0;
  line-height: 1;
  text-shadow: 0 8px 36px rgba(0, 0, 0, 0.45);
}

.line {
  margin: 0;
  font-size: 14px;
  font-weight: 300;
  letter-spacing: 0.18em;
  color: var(--mute);
  line-height: 1.9;
}

.line.soft {
  color: var(--soft);
  letter-spacing: 0.28em;
  font-size: 13px;
}

/* ── liquid ripple (reusable) ── */
.liquid-ripple {
  --ripple-blue: rgba(56, 189, 248, 0.55);
  --ripple-green: rgba(134, 239, 172, 0.45);
  position: relative;
  overflow: hidden;
  isolation: isolate;
}

.liquid-ripple::before,
.liquid-ripple::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
  opacity: 0;
  transform: translate(-50%, -50%) scale(0.8);
  will-change: transform, opacity;
}

/* layer 1 — tech blue, fast */
.liquid-ripple::before {
  background: radial-gradient(
    circle at center,
    var(--ripple-blue) 0%,
    rgba(56, 189, 248, 0.28) 35%,
    rgba(56, 189, 248, 0.08) 60%,
    transparent 72%
  );
}

/* layer 2 — soft green, slower */
.liquid-ripple::after {
  background: radial-gradient(
    circle at center,
    var(--ripple-green) 0%,
    rgba(134, 239, 172, 0.22) 40%,
    rgba(52, 211, 153, 0.06) 62%,
    transparent 75%
  );
}

.liquid-ripple > * {
  position: relative;
  z-index: 1;
}

/* hover: dual-wave expand */
.liquid-ripple:hover::before {
  animation: liquid-wave-blue 1.2s ease-out forwards;
}

.liquid-ripple:hover::after {
  animation: liquid-wave-green 1.5s ease-out 0.2s forwards;
}

/* active / selected: continuous pulse */
.liquid-ripple:active::before,
.liquid-ripple.is-active::before,
.liquid-ripple[aria-pressed="true"]::before {
  animation: liquid-pulse-blue 3s ease-in-out infinite;
}

.liquid-ripple:active::after,
.liquid-ripple.is-active::after,
.liquid-ripple[aria-pressed="true"]::after {
  animation: liquid-pulse-green 3s ease-in-out 0.2s infinite;
}

/* 0 → 1 → 0 opacity, scale 0.8 → 1.2, expand to 300% / 250% of host */
@keyframes liquid-wave-blue {
  0% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0.8);
  }
  35% {
    opacity: 1;
  }
  100% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(3); /* 300% */
  }
}

@keyframes liquid-wave-green {
  0% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0.8);
  }
  40% {
    opacity: 1;
  }
  100% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(2.5); /* 250% */
  }
}

@keyframes liquid-pulse-blue {
  0%,
  100% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0.8);
  }
  40% {
    opacity: 0.85;
    transform: translate(-50%, -50%) scale(1.2);
  }
  70% {
    opacity: 0.35;
    transform: translate(-50%, -50%) scale(1.65);
  }
  100% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(2.2);
  }
}

@keyframes liquid-pulse-green {
  0%,
  100% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0.8);
  }
  45% {
    opacity: 0.75;
    transform: translate(-50%, -50%) scale(1.15);
  }
  75% {
    opacity: 0.28;
    transform: translate(-50%, -50%) scale(1.55);
  }
  100% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(2);
  }
}

.dl {
  /* sit lower on the lake, per design */
  margin-top: clamp(72px, 16vh, 140px);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-width: 168px;
  height: 48px;
  padding: 0 22px;
  border-radius: 10px;
  background: var(--box);
  border: 1px solid var(--box-border);
  color: var(--text);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.08em;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
  transition:
    background 0.18s ease,
    border-color 0.18s ease,
    transform 0.18s ease,
    box-shadow 0.25s ease;
  opacity: 0;
  animation: in 0.9s ease 0.28s forwards;
}

.dl:hover {
  background: var(--box-hover);
  border-color: rgba(56, 189, 248, 0.35);
  transform: translateY(-1px);
  box-shadow:
    0 12px 40px rgba(0, 0, 0, 0.35),
    0 0 24px rgba(56, 189, 248, 0.12);
}

.dl:active {
  transform: translateY(0);
}

.android {
  opacity: 0.9;
  flex-shrink: 0;
}

.spacer {
  flex: 1;
}

@keyframes in {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .hero,
  .dl {
    animation: none;
    opacity: 1;
  }

  .liquid-ripple:hover::before,
  .liquid-ripple:hover::after,
  .liquid-ripple:active::before,
  .liquid-ripple:active::after,
  .liquid-ripple.is-active::before,
  .liquid-ripple.is-active::after {
    animation: none;
    opacity: 0;
  }
}