:root {
  --ink: #20202a;
  --muted: #62626e;
  --paper: #f7f5f0;
  --glass: rgba(255, 255, 255, 0.58);
  --line: rgba(255, 255, 255, 0.82);
  --shadow: 0 24px 70px rgba(54, 52, 68, 0.14), 0 4px 16px rgba(54, 52, 68, 0.08);
  --blue: #a9bdf8;
  --lilac: #c9b5ee;
  --blush: #edbed2;
  --peach: #f4c9aa;
  --mint: #b9dbd2;
  --radius: 30px;
  --serif: "Iowan Old Style", "Palatino Linotype", "Noto Serif TC", serif;
  --sans: "Avenir Next", "PingFang TC", "Noto Sans TC", sans-serif;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--paper);
}

body {
  margin: 0;
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.75;
  background:
    radial-gradient(circle at 10% 12%, rgba(244, 201, 170, .44), transparent 24rem),
    radial-gradient(circle at 92% 4%, rgba(169, 189, 248, .45), transparent 27rem),
    radial-gradient(circle at 75% 72%, rgba(237, 190, 210, .25), transparent 28rem),
    linear-gradient(145deg, #f8f7f3, #eff1f7 54%, #f8f4f2);
  min-height: 100vh;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: .28;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.08'/%3E%3C/svg%3E");
  z-index: 20;
}

a { color: inherit; }

.skip-link {
  position: fixed;
  left: 18px;
  top: -60px;
  z-index: 99;
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--ink);
  color: white;
  text-decoration: none;
  transition: top .2s ease;
}

.skip-link:focus { top: 18px; }

.shell {
  width: min(1160px, calc(100% - 36px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 14px;
  z-index: 10;
  padding-top: 14px;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 10px 14px 10px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(250, 250, 250, .66);
  box-shadow: 0 12px 36px rgba(50, 50, 64, .11), inset 0 1px 0 white;
  backdrop-filter: blur(20px) saturate(145%);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 720;
  letter-spacing: -.02em;
  text-decoration: none;
  white-space: nowrap;
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 13px;
  box-shadow: 0 5px 16px rgba(92, 93, 128, .22);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-links a {
  padding: 8px 14px;
  border-radius: 999px;
  color: var(--muted);
  font-size: .92rem;
  font-weight: 650;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a:focus-visible,
.nav-links a[aria-current="page"] {
  color: var(--ink);
  background: rgba(255, 255, 255, .78);
  outline: none;
}

.hero {
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  align-items: center;
  gap: 70px;
  min-height: 680px;
  padding: 100px 0 72px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 18px;
  color: #575266;
  font-size: .8rem;
  font-weight: 750;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 32px;
  height: 1px;
  background: linear-gradient(90deg, var(--blue), var(--blush));
}

h1, h2, h3 { line-height: 1.2; }

h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(3.4rem, 7.2vw, 6.8rem);
  font-weight: 600;
  letter-spacing: -.065em;
}

.hero-copy {
  max-width: 630px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(1rem, 2vw, 1.2rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 11px 20px;
  border: 1px solid rgba(255, 255, 255, .8);
  border-radius: 999px;
  background: rgba(255, 255, 255, .72);
  box-shadow: 0 10px 30px rgba(58, 55, 75, .11), inset 0 1px 0 white;
  font-weight: 720;
  text-decoration: none;
  transition: transform .2s ease, box-shadow .2s ease;
}

.button.primary {
  background: linear-gradient(120deg, rgba(172, 191, 248, .72), rgba(235, 190, 213, .66));
}

.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 14px 34px rgba(58, 55, 75, .16), inset 0 1px 0 white;
  outline: 2px solid rgba(104, 105, 142, .36);
  outline-offset: 3px;
}

.logo-stage {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 430px;
}

.logo-stage::before,
.logo-stage::after {
  content: "";
  position: absolute;
  border: 1px solid rgba(255, 255, 255, .75);
  border-radius: 50%;
  background: rgba(255, 255, 255, .18);
  backdrop-filter: blur(8px);
}

.logo-stage::before { width: 390px; height: 390px; }
.logo-stage::after { width: 300px; height: 300px; }

.app-logo {
  position: relative;
  z-index: 2;
  width: min(300px, 72vw);
  aspect-ratio: 1;
  border-radius: 30%;
  box-shadow: 0 38px 80px rgba(76, 75, 96, .24), 0 6px 20px rgba(76, 75, 96, .16);
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0) rotate(-1deg); }
  50% { transform: translateY(-12px) rotate(1deg); }
}

.section { padding: 94px 0; }

.section-heading {
  display: grid;
  grid-template-columns: .7fr 1.3fr;
  gap: 50px;
  align-items: end;
  margin-bottom: 38px;
}

.section-heading h2,
.page-hero h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(2.5rem, 5vw, 4.6rem);
  font-weight: 600;
  letter-spacing: -.05em;
}

.section-heading p { margin: 0; color: var(--muted); }

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.glass-card {
  position: relative;
  overflow: hidden;
  min-height: 270px;
  padding: 30px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--glass);
  box-shadow: var(--shadow), inset 0 1px 0 white;
  backdrop-filter: blur(22px) saturate(130%);
}

.glass-card::after {
  content: "";
  position: absolute;
  top: -60px;
  right: -40px;
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: var(--glow, rgba(169, 189, 248, .4));
  filter: blur(28px);
}

.glass-card:nth-child(2) { --glow: rgba(185, 219, 210, .52); }
.glass-card:nth-child(3) { --glow: rgba(244, 201, 170, .48); }

.card-number {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  margin-bottom: 54px;
  border: 1px solid rgba(255, 255, 255, .92);
  border-radius: 14px;
  background: rgba(255, 255, 255, .55);
  color: #62647d;
  font-family: var(--serif);
  font-weight: 700;
}

.glass-card h3 { margin: 0 0 10px; font-size: 1.24rem; }
.glass-card p { margin: 0; color: var(--muted); }

.callout {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 30px;
  align-items: center;
  margin: 24px 0 0;
  padding: 40px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(120deg, rgba(255, 255, 255, .66), rgba(221, 224, 246, .62), rgba(247, 220, 208, .6));
  box-shadow: var(--shadow), inset 0 1px 0 white;
}

.callout h2 { margin: 0 0 8px; font-family: var(--serif); font-size: clamp(2rem, 4vw, 3.4rem); letter-spacing: -.045em; }
.callout p { margin: 0; color: var(--muted); }

.page-hero {
  padding: 120px 0 56px;
  max-width: 850px;
}

.page-hero p {
  max-width: 680px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 1.1rem;
}

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  margin-top: 28px;
  color: var(--muted);
  font-size: .9rem;
}

.content-layout {
  display: grid;
  grid-template-columns: 240px minmax(0, 740px);
  gap: 70px;
  align-items: start;
  padding-bottom: 110px;
}

.toc {
  position: sticky;
  top: 100px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: rgba(255, 255, 255, .48);
  backdrop-filter: blur(18px);
}

.toc strong { display: block; margin: 0 0 10px; font-size: .88rem; }
.toc a { display: block; padding: 5px 0; color: var(--muted); font-size: .88rem; text-decoration: none; }
.toc a:hover, .toc a:focus-visible { color: var(--ink); text-decoration: underline; text-underline-offset: 4px; }

.prose section {
  scroll-margin-top: 110px;
  margin-bottom: 22px;
  padding: 34px;
  border: 1px solid rgba(255, 255, 255, .78);
  border-radius: 28px;
  background: rgba(255, 255, 255, .48);
  box-shadow: 0 12px 42px rgba(57, 55, 70, .07), inset 0 1px 0 white;
  backdrop-filter: blur(18px);
}

.prose h2 { margin: 0 0 14px; font-family: var(--serif); font-size: 1.75rem; letter-spacing: -.025em; }
.prose h3 { margin: 24px 0 8px; font-size: 1.05rem; }
.prose p, .prose li { color: #50505b; }
.prose p:first-of-type { margin-top: 0; }
.prose p:last-child { margin-bottom: 0; }
.prose ul { padding-left: 1.25rem; }
.prose li + li { margin-top: 7px; }

.notice {
  padding: 20px 22px;
  border-left: 3px solid #8f91ba;
  border-radius: 0 18px 18px 0;
  background: rgba(225, 225, 245, .52);
}

.faq details {
  border-top: 1px solid rgba(74, 72, 84, .13);
  padding: 18px 0;
}

.faq details:first-of-type { border-top: 0; }
.faq summary { cursor: pointer; font-weight: 720; }
.faq summary::marker { color: #8a89a7; }
.faq details p { margin: 10px 0 0; }

.site-footer { padding: 0 0 34px; }

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 30px;
  align-items: center;
  padding: 22px 4px;
  border-top: 1px solid rgba(57, 55, 70, .14);
  color: var(--muted);
  font-size: .88rem;
}

.footer-links { display: flex; gap: 18px; }
.footer-links a { text-underline-offset: 4px; }

.error-page {
  display: grid;
  place-items: center;
  min-height: 100vh;
  padding: 30px;
  text-align: center;
}

.error-card { max-width: 650px; }
.error-code { margin: 0; font-family: var(--serif); font-size: clamp(6rem, 25vw, 13rem); line-height: .8; color: rgba(76, 75, 96, .17); }
.error-card h1 { margin: -18px 0 14px; font-size: clamp(2.2rem, 5vw, 4rem); }

@media (max-width: 860px) {
  .hero { grid-template-columns: 1fr; gap: 20px; min-height: auto; padding-top: 90px; }
  .logo-stage { order: -1; min-height: 330px; }
  .logo-stage::before { width: 310px; height: 310px; }
  .logo-stage::after { width: 240px; height: 240px; }
  .app-logo { width: 230px; }
  .section-heading { grid-template-columns: 1fr; gap: 14px; }
  .card-grid { grid-template-columns: 1fr; }
  .glass-card { min-height: 230px; }
  .card-number { margin-bottom: 34px; }
  .content-layout { grid-template-columns: 1fr; gap: 24px; }
  .toc { position: static; }
}

@media (max-width: 620px) {
  .shell { width: min(calc(100% - 24px), 1160px); }
  .site-header { top: 8px; padding-top: 8px; }
  .nav { gap: 4px; align-items: center; border-radius: 26px; }
  .brand span { display: none; }
  .brand img { width: 38px; height: 38px; }
  .nav-links { min-width: 0; flex: 1; justify-content: flex-end; gap: 0; }
  .nav-links a { padding: 8px 7px; font-size: .78rem; }
  h1 { font-size: clamp(3.2rem, 17vw, 5rem); }
  .hero { padding-top: 62px; }
  .hero-actions, .button { width: 100%; }
  .section { padding: 70px 0; }
  .callout { grid-template-columns: 1fr; padding: 28px; }
  .page-hero { padding-top: 86px; }
  .prose section { padding: 26px 22px; }
  .footer-inner { align-items: flex-start; flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}