:root {
  --ink: #f4efe8;
  --ink-dim: rgba(244, 239, 232, 0.72);
  --ink-faint: rgba(244, 239, 232, 0.45);
  --brand: #7a45d0;
  --brand-soft: #b48cff;
  --panel: rgba(18, 12, 28, 0.55);
  --line: rgba(255, 255, 255, 0.12);
  --font-display: "Noto Serif SC", "Songti SC", serif;
  --font-ui: "Outfit", "PingFang SC", sans-serif;
}

* {
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-ui);
  color: var(--ink);
  background: #0b0812;
  min-height: 100vh;
}

.bg {
  position: fixed;
  inset: 0;
  background:
    linear-gradient(120deg, rgba(20, 8, 36, 0.55), rgba(8, 10, 22, 0.35)),
    url("./assets/background.jpg") center / cover no-repeat;
  transform: scale(1.04);
  animation: drift 18s ease-in-out infinite alternate;
  z-index: 0;
}

.veil {
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 55% at 20% 15%, rgba(122, 69, 208, 0.28), transparent 60%),
    linear-gradient(180deg, rgba(8, 6, 14, 0.35) 0%, rgba(8, 6, 14, 0.78) 70%, #0b0812 100%);
  z-index: 1;
}

@keyframes drift {
  from {
    transform: scale(1.04) translate3d(0, 0, 0);
  }
  to {
    transform: scale(1.08) translate3d(-1.2%, -0.8%, 0);
  }
}

.shell,
.hero,
.packs {
  position: relative;
  z-index: 2;
}

.shell {
  width: min(1180px, calc(100% - 64px));
  margin: 0 auto;
  padding: 72px 0 80px;
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, 0.85fr);
  gap: 56px 64px;
  align-items: center;
}

.hero {
  display: flex;
  flex-direction: column;
  justify-content: center;
  max-width: 36rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-bottom: 28px;
  animation: rise 0.8s ease both;
}

.mark {
  width: 80px;
  height: 80px;
  object-fit: contain;
  border-radius: 20px;
  filter: drop-shadow(0 12px 32px rgba(122, 69, 208, 0.45));
}

.brand h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2rem, 3vw, 3rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.02em;
}

.brand .ver {
  margin-left: 0.45em;
  font-family: var(--font-ui);
  font-size: 0.42em;
  font-weight: 600;
  letter-spacing: 0.08em;
  vertical-align: middle;
  color: var(--brand-soft);
}

.lede {
  margin: 0 0 32px;
  max-width: 32rem;
  font-size: 1.08rem;
  line-height: 1.75;
  color: var(--ink-dim);
  animation: rise 0.9s ease 0.08s both;
}

.cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  animation: rise 1s ease 0.16s both;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 152px;
  padding: 15px 24px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.06);
  color: var(--ink);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease, opacity 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(180, 140, 255, 0.45);
}

.btn.primary {
  background: linear-gradient(135deg, #8a55e0, #5b2fb0);
  border-color: transparent;
  box-shadow: 0 12px 32px rgba(91, 47, 176, 0.35);
}

.btn[aria-disabled="true"] {
  opacity: 0.45;
  pointer-events: none;
}

.hint {
  margin: 20px 0 0;
  font-size: 0.85rem;
  color: var(--ink-faint);
  animation: rise 1.05s ease 0.22s both;
}

.packs {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  animation: rise 1s ease 0.2s both;
}

.pack {
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--panel);
  backdrop-filter: blur(16px);
  transition: border-color 0.25s ease, transform 0.25s ease, background 0.25s ease;
}

.pack.is-active {
  border-color: rgba(180, 140, 255, 0.55);
  background: rgba(28, 18, 44, 0.72);
  transform: translateY(-2px);
}

.pack h2 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 1.2rem;
}

.pack > p {
  margin: 0 0 14px;
  color: var(--ink-dim);
  font-size: 0.86rem;
}

.files {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.files a {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  padding: 11px 12px;
  border-radius: 10px;
  border: 1px solid transparent;
  background: rgba(255, 255, 255, 0.04);
  color: var(--ink);
  text-decoration: none;
  font-size: 0.86rem;
}

.files a:hover {
  border-color: rgba(180, 140, 255, 0.35);
}

.files .meta {
  color: var(--ink-faint);
  white-space: nowrap;
  flex-shrink: 0;
}

.files .empty {
  color: var(--ink-faint);
  font-size: 0.86rem;
  padding: 8px 0;
}

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

/* 手机端：保持原纵向节奏 */
@media (max-width: 900px) {
  .shell {
    width: 100%;
    min-height: auto;
    display: flex;
    flex-direction: column;
    gap: 0;
    padding: 0;
  }

  .hero {
    max-width: none;
    min-height: auto;
    padding: 64px clamp(32px, 6vw, 72px) 40px;
  }

  .mark {
    width: 72px;
    height: 72px;
    border-radius: 18px;
  }

  .brand {
    margin-bottom: 22px;
  }

  .brand h1 {
    font-size: clamp(1.75rem, 4.5vw, 2.8rem);
  }

  .lede {
    margin-bottom: 28px;
    font-size: clamp(1rem, 2vw, 1.15rem);
  }

  .packs {
    gap: 16px;
    padding: 0 clamp(32px, 6vw, 72px) 48px;
  }
}