/* 基础层 token 与 web/src/index.css / DESIGN.md 保持同源，改动请两边对齐。 */

:root {
  color-scheme: light;

  --font-heading: "Source Serif 4", "Songti SC", "Noto Serif SC", STSong, Georgia, serif;
  --font-body: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Noto Sans SC",
    "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace; /* taste-skill-ignore */

  --bg: oklch(0.985 0.002 250);
  --surface: #ffffff;
  --surface-raised: oklch(0.965 0.002 250);
  --border: oklch(0.90 0.003 250);
  --border-light: oklch(0.935 0.002 250);
  --text-primary: oklch(0.18 0.01 250);
  --text-secondary: oklch(0.38 0.01 250);
  --text-muted: oklch(0.50 0.008 250);
  --accent: oklch(0.48 0.095 150);
  --accent-hover: oklch(0.40 0.100 150);
  --on-accent: #ffffff;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-full: 9999px;

  --space-xs: 6px;
  --space-sm: 10px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-section: 64px;

  --measure: 880px;
  --gutter: 24px;
  --grain-opacity: 0.045;

  --orbit-size: 260px;
  --orbit-inner: 164px;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: oklch(0.15 0.008 250);
    --surface: oklch(0.19 0.01 250);
    --surface-raised: oklch(0.23 0.012 250);
    --border: oklch(0.28 0.012 250);
    --border-light: oklch(0.24 0.01 250);
    --text-primary: oklch(0.95 0.005 250);
    --text-secondary: oklch(0.78 0.012 250);
    --text-muted: oklch(0.65 0.01 250);
    --accent: oklch(0.78 0.11 150);
    --accent-hover: oklch(0.86 0.10 150);
    --on-accent: oklch(0.18 0.02 150);
    --grain-opacity: 0.05;
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  overflow-x: hidden;
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.72;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 9;
  pointer-events: none;
  opacity: var(--grain-opacity);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)'/%3E%3C/svg%3E");
}

.masthead,
main,
.colophon {
  position: relative;
  z-index: 1;
  max-width: var(--measure);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

a {
  color: inherit;
  text-decoration: none;
}

a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.masthead {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 32px;
  padding-bottom: 24px;
}

.wordmark {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-indent: 0.28em;
}

.wordmark.small {
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

.nav-link {
  transition: color 150ms cubic-bezier(0.16, 1, 0.3, 1);
}

.nav-link:hover {
  color: var(--text-primary);
}

.github-nav {
  font-weight: 500;
  color: var(--text-primary);
}

.app-nav-button {
  padding: 6px 14px;
  background: var(--surface-raised);
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  transition: background-color 150ms cubic-bezier(0.16, 1, 0.3, 1),
    color 150ms cubic-bezier(0.16, 1, 0.3, 1);
}

.app-nav-button:hover {
  background: var(--accent);
  color: var(--on-accent);
}

/* 引导区：左右分栏，居中平衡 */
.hero {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  align-items: center;
  gap: 40px;
  padding-top: clamp(48px, 8vh, 84px);
  overflow: clip;
}

h1 {
  margin: 0;
  font-family: var(--font-heading);
  font-size: clamp(2.8rem, 6.2vw, 4.2rem);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: 0.015em;
}

.lede {
  max-width: 34em;
  margin: var(--space-lg) 0 0;
  color: var(--text-secondary);
  font-size: 1.1875rem;
  line-height: 1.75;
}

.actions {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

.button {
  display: inline-block;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  background: var(--accent);
  color: var(--on-accent);
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  transition: background-color 150ms cubic-bezier(0.16, 1, 0.3, 1),
    transform 150ms cubic-bezier(0.16, 1, 0.3, 1);
}

.button:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}

.text-link {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  padding-bottom: 2px;
  transition: color 150ms cubic-bezier(0.16, 1, 0.3, 1);
}

.text-link:hover {
  color: var(--text-primary);
}

.hero-visual {
  display: grid;
  place-items: center;
  overflow: clip;
}

.orbits {
  position: relative;
  width: var(--orbit-size);
  height: var(--orbit-size);
  max-width: 100%;
  display: grid;
  place-items: center;
}

.ring {
  position: absolute;
  inset: 0;
  margin: auto;
  border-radius: 50%;
}

.ring-outer {
  width: var(--orbit-size);
  height: var(--orbit-size);
  box-shadow: inset 0 0 0 1px color-mix(in oklch, var(--text-muted) 38%, transparent); /* taste-skill-ignore */
}

.ring-inner {
  width: var(--orbit-inner);
  height: var(--orbit-inner);
  box-shadow: inset 0 0 0 1px color-mix(in oklch, var(--text-muted) 24%, transparent); /* taste-skill-ignore */
}

.spin {
  position: absolute;
  inset: 0;
  margin: auto;
}

.spin-outer {
  width: var(--orbit-size);
  height: var(--orbit-size);
  max-width: 100%;
  animation: orbit-turn 36s linear infinite;
}

.spin-inner {
  width: var(--orbit-inner);
  height: var(--orbit-inner);
  max-width: 100%;
  animation: orbit-turn 26s linear infinite reverse;
}

.satellite {
  position: absolute;
  top: -3.5px;
  left: 50%;
  width: 7px;
  height: 7px;
  margin-left: -3.5px;
  border-radius: 50%;
}

.satellite-lead {
  background: var(--accent);
}

.satellite-trail {
  width: 4px;
  height: 4px;
  margin-left: -2px;
  top: -2px;
  background: var(--text-muted);
}

@keyframes orbit-turn {
  to {
    transform: rotate(360deg);
  }
}

.chapter {
  margin-top: clamp(72px, 11vh, 108px);
  scroll-margin-top: 32px;
}

h2 {
  margin: 0 0 20px;
  font-family: var(--font-heading);
  font-size: 1.45rem;
  font-weight: 500;
  line-height: 1.4;
  letter-spacing: 0.01em;
}

.prose {
  max-width: 38em;
  margin: 0 0 20px;
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.75;
}

.prose:last-child {
  margin-bottom: 0;
}

/* 记录片段展示 (主次分层，避免相同尺寸卡片行) */
.fragments-layout {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 18px;
  margin-top: var(--space-lg);
}

.fragments-sub {
  display: grid;
  gap: 18px;
}

.fragment {
  min-height: 204px;
  padding: 26px 28px;
  background: var(--surface);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.fragment-lead {
  min-height: 426px;
}

.fragment-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.84375rem;
  color: var(--text-muted);
}

.tag {
  padding: 3px 12px;
  border-radius: var(--radius-full);
  background: var(--surface-raised);
  color: var(--text-secondary);
  font-size: 0.84375rem;
  font-weight: 500;
}

.stamp {
  font-size: 0.84375rem;
  color: var(--text-muted);
}

.fragment-body {
  margin: 16px 0;
  color: var(--text-primary);
  font-size: 1.0625rem;
  line-height: 1.8;
}

.fragment-sign {
  text-align: right;
  font-size: 0.84375rem;
  color: var(--text-muted);
}

/* 独特点立柱 */
.pillars {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-top: var(--space-lg);
}

.pillar {
  padding: 26px;
  background: var(--surface);
  border-radius: var(--radius-lg);
}

.pillar h3 {
  margin: 0 0 12px;
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--text-primary);
}

.pillar p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.7;
}

/* 恋爱记忆叙事流 */
.experience-flow {
  display: grid;
  gap: 14px;
  margin-top: 32px;
}

.exp-block {
  padding: 22px 26px;
  background: var(--surface-raised);
  border-radius: var(--radius-md);
}

.exp-block h3 {
  margin: 0 0 10px;
  font-family: var(--font-heading);
  font-size: 1.0625rem;
  font-weight: 500;
  color: var(--text-primary);
}

.exp-block p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.68;
}

/* 多渠道接入流 */
.channel-flow {
  display: grid;
  gap: 14px;
  margin-top: var(--space-lg);
}

.channel-block {
  padding: 22px 26px;
  background: var(--surface);
  border-radius: var(--radius-md);
}

.channel-block h3 {
  margin: 0 0 8px;
  font-family: var(--font-heading);
  font-size: 1.0625rem;
  font-weight: 500;
  color: var(--text-primary);
}

.channel-block p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.68;
}

/* 部署方式面板 */
.deploy-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  margin-top: var(--space-lg);
  margin-bottom: var(--space-lg);
}

.deploy-card {
  padding: 24px;
  background: var(--surface);
  border-radius: var(--radius-lg);
}

.deploy-card h3 {
  margin: 0 0 10px;
  font-family: var(--font-heading);
  font-size: 1.0625rem;
  font-weight: 500;
  color: var(--text-primary);
}

.deploy-card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.68;
}

/* 代码块 */
.code {
  margin: 24px 0;
  padding: 20px 24px;
  overflow-x: auto;
  background: var(--surface-raised);
  border-radius: var(--radius-md);
}

.code code {
  font-family: var(--font-mono); /* taste-skill-ignore */
  font-size: 0.9375rem;
  line-height: 1.75;
  letter-spacing: 0.02em;
  color: var(--text-primary);
  white-space: pre;
}

.inline-link {
  color: var(--text-primary);
  font-weight: 500;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: opacity 150ms cubic-bezier(0.16, 1, 0.3, 1);
}

.inline-link:hover {
  opacity: 0.8;
}

/* 常见问题：一体化容器，零线条 */
.faq-container {
  display: grid;
  gap: 12px;
  margin-top: var(--space-lg);
}

.faq-item {
  background: var(--surface);
  border-radius: var(--radius-md);
  padding: 18px 24px;
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  list-style: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  font-size: 1.125rem;
  color: var(--text-muted);
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item p {
  max-width: 36em;
  margin: 14px 0 0;
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.75;
}

/* 结束号召横幅 */
.closing-callout {
  margin-top: clamp(72px, 11vh, 108px);
  padding: 44px 48px;
  background: var(--surface-raised);
  border-radius: var(--radius-lg);
}

.closing-callout h2 {
  margin: 0 0 14px;
  font-family: var(--font-heading);
  font-size: 1.5rem;
}

/* 页尾 */
.colophon {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-top: clamp(64px, 9vh, 96px);
  padding-bottom: 56px;
}

.colophon-quote {
  margin: 8px 0 0;
  color: var(--text-muted);
  font-size: 0.875rem;
  line-height: 1.6;
}

.colophon-links {
  display: flex;
  gap: 24px;
  white-space: nowrap;
}

.footer-link {
  font-size: 0.875rem;
  color: var(--text-secondary);
  transition: color 150ms cubic-bezier(0.16, 1, 0.3, 1);
}

.footer-link:hover {
  color: var(--text-primary);
}

/* 响应式调整 */
@media (max-width: 880px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .fragments-layout {
    grid-template-columns: 1fr;
  }

  .fragment-lead {
    min-height: 204px;
  }

  .pillars,
  .deploy-options {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  :root {
    --orbit-size: 200px;
    --orbit-inner: 126px;
    --gutter: 20px;
  }

  .masthead {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .nav-links {
    flex-wrap: wrap;
    gap: 14px;
    font-size: 0.875rem;
  }

  .actions {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .closing-callout {
    padding: 32px 24px;
  }

  .colophon {
    flex-direction: column;
    gap: 24px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .spin {
    animation: none;
  }

  .button,
  .text-link,
  .nav-link,
  .footer-link,
  .inline-link {
    transition: none;
  }
}