/* 知几官网 · 与 apps/mobile/src/theme.ts 色板一一对应 */
:root {
  --background: #F7FBFA;
  --surface: #FFFFFF;
  --surface-muted: #EEF4F3;
  --ink: #172629;
  --ink-soft: #65777A;
  --ink-faint: #93A2A4;
  --line: #DDE8E8;
  --accent: #9EDFF2;
  --accent-strong: #5ABBD9;
  --mint: #61B59E;
  --mint-soft: #E8F6F1;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 22px;
  --radius-pill: 999px;
  --card-shadow: 0 8px 18px rgba(23, 38, 41, 0.1);
  --card-shadow-hover: 0 14px 28px rgba(23, 38, 41, 0.14);
  --font-sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-serif: "Noto Serif SC", "Songti SC", "SimSun", serif;
  --nav-h: 64px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--background);
  color: var(--ink);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; }
a { color: inherit; text-decoration: none; }

.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 26px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}
.btn-sm { min-height: 40px; padding: 0 20px; font-size: 14px; }
.btn-primary { background: var(--accent-strong); color: #fff; box-shadow: 0 6px 16px rgba(90, 187, 217, 0.35); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 22px rgba(90, 187, 217, 0.42); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--accent-strong); color: var(--accent-strong); }
.btn-disabled {
  background: var(--surface-muted);
  color: var(--ink-faint);
  cursor: not-allowed;
  width: 100%;
}

/* ---------- 导航 ---------- */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  background: rgba(247, 251, 250, 0.86);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease;
}
.nav.is-scrolled { border-bottom-color: var(--line); }
.nav-inner {
  max-width: 1120px;
  margin: 0 auto;
  height: var(--nav-h);
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 28px;
}
.nav-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; }
.nav-logo { width: 30px; height: 30px; }
.nav-en { font-size: 12px; font-weight: 600; letter-spacing: 0.14em; color: var(--ink-faint); margin-left: -2px; }
.nav-links { display: none; gap: 26px; margin-left: auto; font-size: 14.5px; color: var(--ink-soft); }
.nav-links a { transition: color 0.2s ease; }
.nav-links a:hover { color: var(--ink); }
.nav > .nav-inner > .btn { margin-left: auto; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  padding: calc(var(--nav-h) + 56px) 0 88px;
}
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(23, 38, 41, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 38, 41, 0.04) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(ellipse 90% 70% at 50% 0%, #000 30%, transparent 75%);
  mask-image: radial-gradient(ellipse 90% 70% at 50% 0%, #000 30%, transparent 75%);
}
.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(48px);
  pointer-events: none;
}
.blob-a {
  width: 340px; height: 340px;
  background: rgba(158, 223, 242, 0.45);
  top: -80px; right: -60px;
  animation: drift 22s ease-in-out infinite alternate;
}
.blob-b {
  width: 260px; height: 260px;
  background: rgba(232, 246, 241, 0.9);
  bottom: -60px; left: -40px;
  animation: drift 26s ease-in-out infinite alternate-reverse;
}
@keyframes drift {
  from { transform: translate(0, 0); }
  to { transform: translate(-36px, 28px); }
}
.hero-inner {
  position: relative;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  flex-direction: column;
  gap: 48px;
  align-items: center;
  text-align: center;
}
.eyebrow {
  display: inline-block;
  padding: 6px 16px;
  border-radius: var(--radius-pill);
  background: rgba(158, 223, 242, 0.25);
  color: var(--ink-soft);
  font-size: 13px;
  letter-spacing: 0.06em;
}
.hero-title {
  margin-top: 22px;
  font-family: var(--font-serif);
  font-size: clamp(34px, 6vw, 56px);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: 0.02em;
}
.hero-sub {
  margin-top: 18px;
  max-width: 520px;
  color: var(--ink-soft);
  font-size: 16px;
}
.hero-cta { margin-top: 30px; display: flex; gap: 14px; flex-wrap: wrap; justify-content: center; }
.hero-en { margin-top: 18px; font-size: 13px; font-weight: 600; letter-spacing: 0.14em; color: var(--ink-faint); }
.hero-note { margin-top: 10px; font-size: 13px; color: var(--ink-faint); }

.hero-mascot { position: relative; width: min(320px, 68vw); }
.mascot-halo {
  position: absolute;
  inset: -14%;
  border-radius: 50%;
  background: radial-gradient(circle, var(--mint-soft) 0%, rgba(232, 246, 241, 0) 70%);
}
.mascot-body { position: relative; display: block; width: 100%; height: auto; }
.mascot-eyes { position: absolute; inset: 0; width: 100%; height: 100%; }
.eyes-gaze { transition: transform 0.5s ease; }
.eyes-blink {
  transform-origin: 512px 570px;
  animation: blink 4.8s ease-in-out infinite;
}
@keyframes blink {
  0%, 91.5%, 100% { transform: scaleY(1); }
  94.5% { transform: scaleY(0.08); }
}

/* ---------- 通用分区 ---------- */
.section { position: relative; padding: 88px 0; overflow: hidden; }
.section-head { text-align: center; max-width: 560px; margin: 0 auto 52px; }
.section-head h2 {
  font-family: var(--font-serif);
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 600;
  letter-spacing: 0.02em;
}
.section-head p { margin-top: 12px; color: var(--ink-soft); font-size: 15.5px; }

.glyph {
  position: absolute;
  width: 420px;
  opacity: 0.06;
  pointer-events: none;
  user-select: none;
}
.glyph-features { top: -60px; right: -120px; transform: rotate(8deg); }
.glyph-download { bottom: -80px; left: -120px; transform: rotate(-6deg); }

/* ---------- 能力卡片 ---------- */
.card-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--card-shadow-hover); }
.card-icon {
  width: 48px; height: 48px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--c, var(--mint));
  background: color-mix(in srgb, var(--c, var(--mint)) 14%, #ffffff);
  margin-bottom: 18px;
}
.card-icon svg { width: 24px; height: 24px; }
.card h3 { font-size: 17.5px; font-weight: 700; }
.card p { margin-top: 8px; font-size: 14.5px; color: var(--ink-soft); }

/* ---------- 信任区 ---------- */
.section-trust { background: var(--surface-muted); }
.trust-list { max-width: 720px; margin: 0 auto; display: flex; flex-direction: column; }
.trust-item {
  display: flex;
  gap: 22px;
  padding: 28px 8px;
  border-bottom: 1px solid var(--line);
  align-items: baseline;
}
.trust-item:last-child { border-bottom: none; }
.trust-no {
  font-family: var(--font-serif);
  font-size: 15px;
  color: var(--accent-strong);
  font-weight: 600;
  flex-shrink: 0;
}
.trust-item h3 { font-size: 18px; font-weight: 700; }
.trust-item p { margin-top: 6px; font-size: 14.5px; color: var(--ink-soft); }

/* ---------- 订阅计划 ---------- */
.pricing-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
  max-width: 1060px;
  margin: 0 auto;
  align-items: stretch;
}
.pricing-card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 30px 26px 26px;
  display: flex;
  flex-direction: column;
  gap: 13px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.pricing-card:hover { transform: translateY(-4px); box-shadow: var(--card-shadow-hover); }
.pricing-card-featured {
  border-color: var(--mint);
  box-shadow: 0 14px 30px rgba(97, 181, 158, 0.2);
}
.pricing-badge {
  position: absolute;
  top: -12px;
  right: 22px;
  padding: 3px 13px;
  border-radius: var(--radius-pill);
  background: var(--mint);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.02em;
}
.pricing-badge-offer { background: #F1A071; }
.pricing-name { font-size: 16.5px; font-weight: 700; }
.pricing-duration { font-size: 12.5px; color: var(--ink-faint); margin-top: -8px; }
.price-row { display: flex; align-items: baseline; gap: 9px; flex-wrap: wrap; }
.price-now { font-family: var(--font-serif); font-size: 38px; font-weight: 700; line-height: 1.1; }
.price-currency { font-size: 20px; margin-right: 1px; }
.price-unit { font-size: 14px; font-weight: 600; color: var(--ink-soft); }
.price-original { color: var(--ink-faint); font-size: 14px; text-decoration: line-through; }
.price-per { font-size: 12.5px; color: var(--ink-faint); margin-top: -6px; min-height: 18px; }
.pricing-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 9px;
  font-size: 13.5px;
  color: var(--ink-soft);
  flex-grow: 1;
  padding-top: 4px;
}
.pricing-features li { display: flex; gap: 8px; align-items: flex-start; line-height: 1.5; }
.pricing-features li::before { content: "✓"; color: var(--mint); font-weight: 800; flex-shrink: 0; }
.pricing-card .btn { width: 100%; margin-top: 4px; }
.pricing-note { text-align: center; margin-top: 28px; font-size: 13px; color: var(--ink-faint); }

/* ---------- 下载区 ---------- */
.download-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  max-width: 920px;
  margin: 0 auto;
}
.dl-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}
.dl-card-web { border-color: var(--mint); background: linear-gradient(180deg, var(--mint-soft), var(--surface) 65%); }
.dl-icon {
  width: 52px; height: 52px;
  border-radius: var(--radius-md);
  background: var(--surface-muted);
  color: var(--ink-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 6px;
}
.dl-card-web .dl-icon { background: rgba(97, 181, 158, 0.16); color: var(--mint); }
.dl-icon svg { width: 26px; height: 26px; }
.dl-card h3 { font-size: 18px; font-weight: 700; }
.dl-desc { font-size: 13.5px; color: var(--ink-faint); flex-grow: 1; }
.dl-card .btn { width: 100%; margin-top: 12px; }

/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--line); padding-top: 56px; }
.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 36px;
  padding-bottom: 48px;
}
.footer-wordmark { width: 108px; height: auto; }
.footer-slogan { margin-top: 12px; font-size: 13px; color: var(--ink-faint); letter-spacing: 0.03em; }
.footer-en { margin-top: 6px; font-size: 12px; font-weight: 600; letter-spacing: 0.12em; color: var(--ink-faint); }
.footer-links { display: flex; flex-wrap: wrap; gap: 34px 56px; }
.footer-col { display: flex; flex-direction: column; gap: 10px; }
.footer-col h4 { font-size: 14px; font-weight: 700; margin-bottom: 4px; }
.footer-col a { font-size: 14px; color: var(--ink-soft); transition: color 0.2s ease; }
.footer-col a:hover { color: var(--accent-strong); }

.site-filing-bar {
  border-top: 1px solid var(--line);
  padding: 18px 24px calc(18px + env(safe-area-inset-bottom));
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 24px;
  font-size: 12.5px;
  color: var(--ink-faint);
}
.site-filing-bar a { color: var(--ink-faint); transition: color 0.2s ease; }
.site-filing-bar a:hover { color: var(--ink-soft); }
.police-filing-link { display: inline-flex; align-items: center; gap: 5px; }
.police-filing-link img { width: 14px; height: 14px; }

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .nav-links { display: flex; }
  .nav > .nav-inner > .btn { margin-left: 0; }
  .hero-inner { flex-direction: row; text-align: left; align-items: center; }
  .hero-copy { flex: 1.2; }
  .hero-cta { justify-content: flex-start; }
  .hero-mascot { flex: 0 0 min(360px, 40%); }
  .card-grid { grid-template-columns: repeat(2, 1fr); }
  .pricing-grid { grid-template-columns: repeat(auto-fit, minmax(218px, 1fr)); }
  .download-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-inner { flex-direction: row; justify-content: space-between; align-items: flex-start; }
}
@media (min-width: 1080px) {
  .card-grid { grid-template-columns: repeat(3, 1fr); }
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .blob, .eyes-blink { animation: none; }
  .eyes-gaze { transition: none; }
  .btn, .card, .pricing-card, .nav { transition: none; }
}