:root {
  --ink: #1a2421;
  --ink-soft: #4a5853;
  --paper: #e8f0ec;
  --mist: #c5d9cf;
  --accent: #2f6b5a;
  --glow-warm: #d4e8c8;
  --glow-cool: #a8c9c0;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-display: "Songti SC", "STSong", "SimSun", serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html,
body {
  min-height: 100%;
}

body {
  font-family: var(--font-sans);
  color: var(--ink);
  background: var(--paper);
  overflow-x: hidden;
}

.atmosphere {
  position: fixed;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(ellipse 80% 60% at 15% 20%, var(--glow-warm) 0%, transparent 55%),
    radial-gradient(ellipse 70% 50% at 85% 75%, var(--glow-cool) 0%, transparent 50%),
    radial-gradient(ellipse 50% 40% at 50% 100%, var(--mist) 0%, transparent 45%),
    linear-gradient(165deg, #f2f7f4 0%, #dce8e2 45%, #c9ddd4 100%);
  animation: drift 18s ease-in-out infinite alternate;
}

.atmosphere::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.05'/%3E%3C/svg%3E");
  opacity: 0.4;
  pointer-events: none;
}

.stage {
  position: relative;
  z-index: 1;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2rem 1.5rem 4.5rem;
  gap: 0.75rem;
}

.beian {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2;
  display: flex;
  justify-content: center;
  padding: 1rem 1.5rem calc(1rem + env(safe-area-inset-bottom));
  pointer-events: none;
}

.beian a {
  pointer-events: auto;
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--ink-soft);
  text-decoration: none;
  opacity: 0.75;
  transition: opacity 0.2s ease, color 0.2s ease;
}

.beian a:hover {
  color: var(--accent);
  opacity: 1;
}

.brand {
  font-family: var(--font-display);
  font-size: clamp(2.75rem, 8vw, 5rem);
  font-weight: 400;
  letter-spacing: -0.02em;
  color: var(--ink);
  line-height: 1;
  animation: rise 0.9s ease-out both;
}

.headline {
  font-family: var(--font-sans);
  font-size: clamp(1rem, 2.5vw, 1.15rem);
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--accent);
  animation: rise 0.9s ease-out 0.15s both;
}

.support {
  max-width: 22rem;
  margin-top: 0.35rem;
  font-size: clamp(0.95rem, 2vw, 1.05rem);
  font-weight: 400;
  line-height: 1.65;
  color: var(--ink-soft);
  animation: rise 0.9s ease-out 0.3s both;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(1.1rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes drift {
  from {
    transform: scale(1) translate(0, 0);
  }
  to {
    transform: scale(1.04) translate(-1.5%, 1%);
  }
}

@media (prefers-reduced-motion: reduce) {
  .atmosphere,
  .brand,
  .headline,
  .support {
    animation: none;
  }
}