/* ===== 威宇引导页 · Design Contract (tech-dark glassmorphism) ===== */
:root {
  --bg-base: #0a0812;
  --veil-top: 0.1;
  --veil-mid: 0.18;
  --veil-bottom: 0.6;
  --c-primary: #ff7bac;
  --c-primary-strong: #ff4d94;
  --c-violet: #a78bfa;
  --c-cyan: #38bdf8;
  --c-amber: #fbbf24;
  --c-lime: #a3e635;
  --c-rose: #fb7185;

  --c-ink: #f6f4ff;
  --c-ink-dim: rgba(246, 244, 255, 0.66);
  --c-ink-mute: rgba(246, 244, 255, 0.42);

  --glass: rgba(14, 11, 26, 0.34);
  --glass-2: rgba(14, 11, 26, 0.48);
  --brd: rgba(255, 255, 255, 0.16);
  --brd-hi: rgba(255, 255, 255, 0.36);

  --r-lg: 22px;
  --r-md: 14px;
  --r-pill: 999px;

  --sp-1: 6px;
  --sp-2: 10px;
  --sp-3: 14px;
  --sp-4: 20px;
  --sp-5: 28px;
  --sp-6: 40px;

  --shadow-card: 0 16px 38px -22px rgba(0, 0, 0, 0.9);
  --shadow-card-hi: 0 26px 52px -24px rgba(0, 0, 0, 0.95);
  --shadow-glow: 0 22px 46px -20px var(--c-primary);

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --dur: 0.32s;

  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }

html {
  background: var(--bg-base);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  color: var(--c-ink);
  background: transparent;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

svg {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.9;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ===== Background stack ===== */
.bg,
.bg-photo,
.bg-grain,
.bg-veil {
  position: fixed;
  inset: 0;
  pointer-events: none;
}

.bg {
  z-index: -4;
  background:
    radial-gradient(58% 48% at 16% 18%, rgba(255, 123, 172, 0.5), transparent 62%),
    radial-gradient(52% 46% at 84% 24%, rgba(167, 139, 250, 0.46), transparent 64%),
    radial-gradient(56% 52% at 62% 90%, rgba(56, 189, 248, 0.34), transparent 62%),
    linear-gradient(158deg, #17102a 0%, #0d0a19 46%, var(--bg-base) 100%);
}

.bg-photo {
  z-index: -3;
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
  opacity: 0;
  transform: scale(1.08);
  transition: opacity 0.9s var(--ease), transform 1.4s var(--ease);
}

.bg-photo.is-ready {
  opacity: 1;
  transform: scale(1.02);
  filter: saturate(1.07) brightness(1.05) contrast(1.02);
  animation: kenburns 46s ease-in-out infinite alternate;
}

.bg-photo.is-loading::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(100deg, transparent 20%, rgba(255, 255, 255, 0.07) 50%, transparent 80%);
  animation: shimmer 1.7s linear infinite;
}

.bg-grain {
  z-index: -2;
  opacity: 0.045;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}

.bg-veil {
  z-index: -1;
  background:
    linear-gradient(180deg,
      rgba(10, 8, 18, var(--veil-top)) 0%,
      rgba(10, 8, 18, var(--veil-mid)) 48%,
      rgba(10, 8, 18, var(--veil-bottom)) 100%),
    radial-gradient(132% 96% at 50% 4%,
      rgba(10, 8, 18, 0) 0%,
      rgba(10, 8, 18, 0.07) 54%,
      rgba(10, 8, 18, 0.58) 100%);
}

.bg-veil::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(80% 60% at 50% 108%, rgba(255, 123, 172, 0.14), transparent 68%);
}

/* ===== Stage ===== */
.stage {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: clamp(24px, 4.6vh, 44px);
  padding: calc(44px + env(safe-area-inset-top)) 20px calc(40px + env(safe-area-inset-bottom));
}

/* ===== Brand ===== */
.brand {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sp-3);
  text-align: center;
  max-width: 640px;
}

.brand::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 156%;
  height: 196%;
  border-radius: 50%;
  background: radial-gradient(closest-side,
    rgba(8, 6, 16, 0.74) 0%,
    rgba(8, 6, 16, 0.46) 44%,
    rgba(8, 6, 16, 0) 100%);
  filter: blur(9px);
  pointer-events: none;
  z-index: -1;
}

.mark {
  width: 68px;
  height: 68px;
  border-radius: 20px;
  display: grid;
  place-items: center;
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: #fff;
  background: linear-gradient(145deg, var(--c-primary), var(--c-violet));
  box-shadow: var(--shadow-glow), inset 0 1px 0 rgba(255, 255, 255, 0.42);
  animation: float 6s ease-in-out infinite;
}

.mark span {
  transform: translateY(-1px);
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.35);
}

.title {
  margin: 0;
  font-size: clamp(30px, 6.6vw, 52px);
  font-weight: 800;
  letter-spacing: 0.03em;
  line-height: 1.12;
  background: linear-gradient(180deg, #ffffff 12%, rgba(246, 244, 255, 0.64) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 2px 10px rgba(0, 0, 0, 0.7)) drop-shadow(0 14px 34px rgba(0, 0, 0, 0.5));
}

.subtitle {
  margin: 0;
  font-size: clamp(13px, 3.5vw, 15.5px);
  letter-spacing: 0.06em;
  color: rgba(246, 244, 255, 0.8);
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.78), 0 1px 3px rgba(0, 0, 0, 0.65);
}

/* ===== Link cards ===== */
.links {
  width: min(940px, 100%);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.link-card {
  position: relative;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  border-radius: var(--r-lg);
  text-decoration: none;
  color: var(--c-ink);
  background: var(--glass);
  border: 1px solid var(--brd);
  box-shadow: var(--shadow-card);
  backdrop-filter: blur(18px) saturate(150%);
  -webkit-backdrop-filter: blur(18px) saturate(150%);
  overflow: hidden;
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease),
    border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
  animation: card-in 0.62s var(--ease) backwards;
  animation-delay: calc(var(--i, 0) * 68ms + 160ms);
}

.link-card::before {
  content: "";
  position: absolute;
  right: -46px;
  bottom: -70px;
  width: 190px;
  height: 190px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--accent, var(--c-primary)) 0%, transparent 68%);
  opacity: 0;
  transition: opacity var(--dur) var(--ease);
  pointer-events: none;
}

.link-card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(115deg, rgba(255, 255, 255, 0.14), transparent 42%);
  opacity: 0;
  transition: opacity var(--dur) var(--ease);
  pointer-events: none;
}

.link-card:hover {
  transform: translateY(-4px);
  background: var(--glass-2);
  border-color: var(--brd-hi);
  box-shadow: var(--shadow-card-hi), 0 0 0 1px rgba(255, 255, 255, 0.05);
}

.link-card:hover::before { opacity: 0.3; }
.link-card:hover::after { opacity: 1; }

.link-card:active { transform: translateY(-1px) scale(0.986); }

.link-card:focus-visible {
  outline: 2px solid var(--accent, var(--c-primary));
  outline-offset: 3px;
}

.ic {
  flex: 0 0 auto;
  width: 44px;
  height: 44px;
  border-radius: var(--r-md);
  display: grid;
  place-items: center;
  color: #fff;
  background: linear-gradient(148deg, var(--accent, var(--c-primary)), rgba(255, 255, 255, 0.06));
  border: 1px solid rgba(255, 255, 255, 0.16);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.24), 0 10px 22px -14px var(--accent, var(--c-primary));
  transition: transform var(--dur) var(--ease);
}

.link-card:hover .ic { transform: scale(1.06) rotate(-3deg); }

.ic svg { width: 22px; height: 22px; }

.tx {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.t {
  font-size: 16px;
  font-weight: 650;
  letter-spacing: 0.01em;
}

.d {
  font-size: 12.5px;
  color: var(--c-ink-dim);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.arw {
  flex: 0 0 auto;
  color: var(--c-ink-mute);
  transition: transform var(--dur) var(--ease), color var(--dur) var(--ease);
}

.arw svg { width: 18px; height: 18px; }

.link-card:hover .arw {
  color: var(--accent, var(--c-primary));
  transform: translateX(4px);
}

/* ===== Accent palette ===== */
[data-accent="pink"] { --accent: var(--c-primary); }
[data-accent="violet"] { --accent: var(--c-violet); }
[data-accent="cyan"] { --accent: var(--c-cyan); }
[data-accent="amber"] { --accent: var(--c-amber); }
[data-accent="lime"] { --accent: var(--c-lime); }
[data-accent="rose"] { --accent: var(--c-rose); }

/* ===== Footer ===== */
.foot {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--sp-2) var(--sp-4);
}

.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: var(--r-pill);
  font: inherit;
  font-size: 13.5px;
  color: var(--c-ink);
  background: var(--glass);
  border: 1px solid var(--brd);
  cursor: pointer;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.btn-ghost svg { width: 15px; height: 15px; }

.btn-ghost:hover:not(:disabled) {
  background: var(--glass-2);
  border-color: var(--brd-hi);
  transform: translateY(-2px);
}

.btn-ghost:focus-visible {
  outline: 2px solid var(--c-primary);
  outline-offset: 3px;
}

.btn-ghost:disabled {
  opacity: 0.6;
  cursor: progress;
  transform: none;
}

.btn-ghost.is-busy svg { animation: spin 0.9s linear infinite; }

.src {
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: rgba(246, 244, 255, 0.56);
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.85);
}

.credit {
  margin: 0;
  max-width: min(760px, 100%);
  text-align: center;
  font-size: 11.5px;
  line-height: 1.7;
  color: rgba(246, 244, 255, 0.56);
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.85);
}

.credit a {
  color: var(--c-ink-dim);
  text-decoration: none;
  border-bottom: 1px dotted rgba(246, 244, 255, 0.34);
  transition: color var(--dur) var(--ease);
}

.credit a:hover { color: var(--c-primary); }

.noscript {
  position: fixed;
  left: 50%;
  top: 18px;
  transform: translateX(-50%);
  z-index: 30;
  width: min(88vw, 520px);
  padding: 12px 16px;
  border-radius: var(--r-md);
  font-size: 13px;
  text-align: center;
  color: var(--c-ink);
  background: rgba(20, 16, 32, 0.9);
  border: 1px solid var(--brd);
}

/* ===== Toast ===== */
.toast {
  position: fixed;
  left: 50%;
  bottom: calc(26px + env(safe-area-inset-bottom));
  transform: translate(-50%, 16px);
  z-index: 30;
  max-width: min(88vw, 540px);
  padding: 10px 18px;
  border-radius: var(--r-pill);
  font-size: 13px;
  text-align: center;
  color: var(--c-ink);
  background: rgba(20, 16, 32, 0.88);
  border: 1px solid var(--brd);
  box-shadow: var(--shadow-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.toast.is-on {
  opacity: 1;
  transform: translate(-50%, 0);
}

/* ===== Motion ===== */
@keyframes card-in {
  from { opacity: 0; transform: translateY(18px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-7px); }
}

@keyframes kenburns {
  from { transform: scale(1.02) translate3d(0, 0, 0); }
  to { transform: scale(1.09) translate3d(-1.4%, -1.1%, 0); }
}

@keyframes shimmer {
  from { transform: translateX(-100%); }
  to { transform: translateX(100%); }
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ===== Responsive ===== */
@media (max-width: 760px) {
  .links { grid-template-columns: 1fr; }
  .stage { gap: clamp(22px, 3.6vh, 32px); }
  .mark { width: 60px; height: 60px; border-radius: 18px; font-size: 26px; }
  .link-card { padding: 14px 16px; }
  .ic { width: 40px; height: 40px; }
}

@media (max-width: 380px) {
  .d { font-size: 12px; }
  .foot { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .bg-photo.is-ready { transform: scale(1.02); }
}