:root {
  --bg: #0b0e14;
  --bg-mid: #141a24;
  --text: #e6edf3;
  --muted: #c8d0d8;
  --accent: #f85149;
  --accent-deep: #c93832;
  --glow: rgba(248, 81, 73, 0.22);
}

* {
  box-sizing: border-box;
}

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

body {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px 20px;
  color: var(--text);
  background:
    radial-gradient(ellipse 80% 55% at 50% -10%, rgba(248, 81, 73, 0.16), transparent 55%),
    radial-gradient(ellipse 70% 50% at 80% 100%, rgba(60, 80, 120, 0.18), transparent 50%),
    linear-gradient(165deg, #10151d 0%, var(--bg) 45%, #090b10 100%);
  font-family: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  overflow-x: hidden;
}

.veil {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(8, 10, 14, 0.15) 0%, rgba(8, 10, 14, 0.35) 100%);
  animation: veil-pulse 12s ease-in-out infinite alternate;
}

.hero {
  position: relative;
  z-index: 1;
  width: min(92vw, 560px);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 28px;
  animation: rise 0.7s ease-out both;
}

.brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}

.brand-logo {
  width: clamp(88px, 18vw, 120px);
  height: auto;
  filter: drop-shadow(0 8px 24px rgba(0, 0, 0, 0.45));
}

.brand-name {
  margin: 0;
  font-size: clamp(2.4rem, 8vw, 3.6rem);
  font-weight: 700;
  letter-spacing: 0.08em;
  line-height: 1.15;
  text-shadow: 0 2px 24px rgba(0, 0, 0, 0.55);
}

.tagline {
  margin: 0;
  font-size: clamp(0.95rem, 2.8vw, 1.15rem);
  color: var(--muted);
  letter-spacing: 0.12em;
}

.actions {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  width: 100%;
}

a {
  color: inherit;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: min(100%, 280px);
  min-height: 52px;
  padding: 14px 28px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: linear-gradient(180deg, var(--accent) 0%, var(--accent-deep) 100%);
  color: #fff;
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-decoration: none;
  box-shadow:
    0 10px 28px rgba(201, 56, 50, 0.35),
    inset 0 1px 0 rgba(255, 255, 255, 0.22);
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease,
    filter 0.2s ease;
}

.download-btn:hover,
.download-btn:focus-visible {
  transform: translateY(-2px) scale(1.02);
  filter: brightness(1.06);
  box-shadow:
    0 14px 34px rgba(201, 56, 50, 0.45),
    inset 0 1px 0 rgba(255, 255, 255, 0.25);
  outline: none;
}

.download-btn:active {
  transform: translateY(0) scale(0.99);
}

.download-btn.is-disabled {
  cursor: not-allowed;
  opacity: 0.55;
  filter: grayscale(0.25);
  box-shadow: none;
  pointer-events: none;
}

.group-link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.45em;
  margin-top: 2px;
  color: #c4b8ae;
  font-size: 0.92rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  text-decoration: none;
  cursor: pointer;
}

.group-id {
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-underline-offset: 4px;
}

.group-link:hover .group-id,
.group-link:focus-visible .group-id {
  color: #ff6b63;
  text-decoration: underline;
  text-decoration-color: rgba(248, 81, 73, 0.55);
}

.group-link:hover,
.group-link:focus-visible {
  color: #e8ddd4;
  outline: none;
}

.notice,
.toast {
  margin: 0;
  padding: 10px 16px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(16, 20, 28, 0.55);
  font-size: 0.95rem;
}

.notice {
  color: #ffb4ae;
}

.toast {
  color: #b7f0c2;
}

.notice.is-hidden,
.toast.is-hidden {
  display: none;
}

@keyframes veil-pulse {
  from {
    opacity: 0.85;
  }
  to {
    opacity: 1;
  }
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .veil,
  .hero,
  .download-btn,
  .group-link {
    animation: none;
    transition: none;
  }

  .download-btn:hover,
  .download-btn:focus-visible {
    transform: none;
  }
}

@media (max-width: 480px) {
  body {
    padding: 24px 16px;
  }

  .hero {
    gap: 22px;
  }

  .download-btn {
    width: 100%;
  }
}