/* ============================================================
   OctoRead 官网设计系统 v2 · 纸感（对齐 LegadoIOS/DesignSystem token）
   方向：米色纸面 + 宋体大标题 + 焦橙点缀；细线分区；深色带只给朗读。
   ============================================================ */
:root {
  --canvas: #F5EFE4;
  --elev: #FFFDF8;
  --outline: #D9C8B6;
  --ink: #26211B;
  --ink-2: #6B5F52;
  --accent: #AD5014;
  --accent-ink: #8F4210;
  --on-dark: #14110F;
  --on-dark-elev: #28211B;
  --on-dark-ink: #EDE4D6;
  --on-dark-ink-2: #A89A88;
  --on-dark-accent: #E49A59;
  --hair: color-mix(in srgb, var(--outline) 55%, transparent);
  --hair-dark: color-mix(in srgb, var(--on-dark-ink-2) 28%, transparent);
  --serif: ui-serif, "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", "New York", serif;
  --sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --nav-h: 56px;
  --radius-panel: 22px;
  --radius-surface: 28px;
  --radius-shot: 30px;
  --shadow-shot: 0 24px 60px rgba(38, 33, 27, 0.16);
  color-scheme: light;
}
[data-theme="dark"] {
  --canvas: #14110F;
  --elev: #28211B;
  --outline: #433830;
  --ink: #EDE4D6;
  --ink-2: #A89A88;
  --accent: #E49A59;
  --accent-ink: #F0B075;
  --hair: color-mix(in srgb, var(--outline) 65%, transparent);
  --shadow-shot: 0 24px 60px rgba(0, 0, 0, 0.5);
  color-scheme: dark;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --canvas: #14110F;
    --elev: #28211B;
    --outline: #433830;
    --ink: #EDE4D6;
    --ink-2: #A89A88;
    --accent: #E49A59;
    --accent-ink: #F0B075;
    --hair: color-mix(in srgb, var(--outline) 65%, transparent);
    --shadow-shot: 0 24px 60px rgba(0, 0, 0, 0.5);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--sans);
  background: var(--canvas);
  color: var(--ink);
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  transition: background 0.35s ease, color 0.35s ease;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 4px; }
::selection { background: var(--accent); color: var(--canvas); }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 28px; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 50; height: var(--nav-h);
  background: color-mix(in srgb, var(--canvas) 74%, transparent);
  -webkit-backdrop-filter: saturate(1.7) blur(20px);
  backdrop-filter: saturate(1.7) blur(20px);
  border-bottom: 1px solid var(--hair);
}
.nav-in {
  max-width: 1080px; margin: 0 auto; padding: 0 28px; height: 100%;
  display: flex; align-items: center; gap: 26px;
}
.brand { display: flex; align-items: center; gap: 9px; font-weight: 600; font-size: 16px; letter-spacing: 0.01em; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand img { width: 24px; height: 24px; border-radius: 6px; }
.brand em { font-style: normal; color: var(--ink-2); font-weight: 500; }
.nav-links { display: flex; gap: 22px; margin-left: 14px; }
.nav-links a { font-size: 13.5px; color: var(--ink-2); }
.nav-links a:hover { color: var(--ink); text-decoration: none; }
.nav-links a[aria-current="page"] { color: var(--accent); }
.nav-r { margin-left: auto; display: flex; align-items: center; gap: 16px; font-size: 13.5px; }
.nav-r .lang { color: var(--ink-2); }
.nav-r .lang:hover { color: var(--ink); }
.icon-btn {
  background: none; border: 0; color: var(--ink-2); cursor: pointer;
  font: inherit; padding: 6px; border-radius: 8px; line-height: 0;
  transition: color 0.2s;
}
.icon-btn:hover { color: var(--accent); }
.icon-btn svg { width: 17px; height: 17px; }
.dl {
  background: var(--accent); color: var(--canvas); font-weight: 600; font-size: 13.5px;
  padding: 8px 16px; border-radius: 999px;
  transition: opacity 0.2s;
}
[data-theme="dark"] .dl { color: var(--on-dark); }
.dl:hover { text-decoration: none; opacity: 0.9; }

/* ---------- 通用 ---------- */
.eyebrow {
  display: block; font-size: 13px; font-weight: 600; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 22px;
}
h1, h2, h3 { color: var(--ink); }
.h-display, h1, h2 { font-family: var(--serif); font-weight: 700; letter-spacing: -0.01em; }
h1 { font-size: clamp(42px, 5.6vw, 68px); line-height: 1.14; }
h2 { font-size: clamp(30px, 3.8vw, 44px); line-height: 1.2; }
.lead { color: var(--ink-2); font-size: clamp(16px, 1.5vw, 18px); max-width: 36em; }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--accent); color: var(--canvas);
  font-weight: 600; font-size: 16px; padding: 15px 30px; border-radius: 999px;
  transition: opacity 0.2s;
}
[data-theme="dark"] .btn { color: var(--on-dark); }
.btn:hover { text-decoration: none; opacity: 0.9; }
.btn svg { width: 17px; height: 17px; }
.textlink {
  font-size: 16px; color: var(--ink);
  border-bottom: 1px solid var(--hair); padding-bottom: 2px;
  transition: color 0.2s, border-color 0.2s;
}
.textlink:hover { text-decoration: none; border-color: var(--accent); color: var(--accent); }

/* 截图 */
.shot {
  border-radius: var(--radius-shot);
  border: 1px solid var(--outline);
  box-shadow: var(--shadow-shot);
  overflow: hidden;
  background: var(--elev);
}

/* ---------- Hero ---------- */
.hero { padding: 168px 0 110px; }
.hero-grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 72px; align-items: center; }
.hero .sub { margin-top: 26px; font-size: clamp(16.5px, 1.6vw, 19px); max-width: 32em; }
.cta-row { margin-top: 38px; display: flex; align-items: center; gap: 26px; flex-wrap: wrap; }
.micro { margin-top: 30px; font-size: 13px; color: var(--ink-2); }
.micro b { color: var(--ink); font-weight: 600; }
.hero .shot { transform: rotate(1.6deg); transition: transform 0.6s cubic-bezier(0.2, 0.8, 0.2, 1); }
.hero .shot:hover { transform: rotate(0); }

/* ---------- 章节 ---------- */
.sect { padding: 110px 0; border-top: 1px solid var(--hair); }
.sect:first-of-type { border-top: 0; }

/* 三步 */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 70px; }
.step { padding: 0 34px; border-left: 1px solid var(--hair); }
.step:first-child { padding-left: 0; border-left: 0; }
.step .num { font-family: var(--serif); font-size: 44px; font-weight: 700; color: var(--accent); line-height: 1; display: block; margin-bottom: 18px; }
.step h3 { font-size: 18px; font-weight: 600; margin-bottom: 8px; }
.step p { font-size: 15px; color: var(--ink-2); }

/* 图文行 */
.duet { display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: center; }
.duet .lead { margin-top: 20px; }
.duet .shots { display: flex; justify-content: center; gap: 18px; align-items: flex-start; }
.duet .shots .shot { width: min(232px, 42vw); }
.duet .shots .shot.offset { margin-top: 44px; }
.lines { margin-top: 34px; border-top: 1px solid var(--hair); list-style: none; }
.lines li {
  padding: 13px 0; border-bottom: 1px solid var(--hair);
  font-size: 15px; color: var(--ink);
  display: flex; gap: 14px; align-items: baseline;
}
.lines li::before {
  content: ""; width: 14px; height: 1.5px; background: var(--accent);
  flex-shrink: 0; position: relative; top: -4px;
}

/* 深色带（朗读） */
.sect-dark { background: var(--on-dark); color: var(--on-dark-ink); border-top: 0; }
.sect-dark .eyebrow { color: var(--on-dark-accent); }
.sect-dark h2, .sect-dark h3 { color: #FBF7EF; }
.sect-dark .lead { color: var(--on-dark-ink-2); }
.sect-dark .shot { border-color: var(--on-dark-elev); box-shadow: 0 24px 60px rgba(0, 0, 0, 0.5); background: var(--on-dark-elev); }
.sect-dark .lines { border-color: var(--hair-dark); }
.sect-dark .lines li { border-color: var(--hair-dark); color: var(--on-dark-ink); }
.sect-dark .lines li::before { background: var(--on-dark-accent); }

/* 坦白三列 */
.plain { display: grid; grid-template-columns: repeat(3, 1fr); gap: 44px; margin-top: 64px; }
.plain h3 {
  font-size: 14px; font-weight: 600; letter-spacing: 0.1em;
  color: var(--accent); text-transform: uppercase; margin-bottom: 12px;
}
.plain p { font-size: 15.5px; color: var(--ink-2); }
.plain p b { color: var(--ink); font-weight: 600; }

/* 结尾 CTA */
.end { padding: 130px 0; text-align: center; border-top: 1px solid var(--hair); }
.end .lead { margin: 20px auto 40px; }

/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--hair); padding: 56px 0 48px; font-size: 13.5px; color: var(--ink-2); }
.foot-top { display: flex; justify-content: space-between; gap: 32px; flex-wrap: wrap; align-items: flex-start; }
.foot-brand { display: flex; align-items: center; gap: 9px; font-weight: 600; color: var(--ink); font-size: 14.5px; }
.foot-brand img { width: 20px; height: 20px; border-radius: 5px; }
.foot-links { display: flex; gap: 22px; flex-wrap: wrap; }
.foot-links a { color: var(--ink-2); }
.foot-links a:hover { color: var(--accent); }
.foot-legal { margin-top: 36px; font-size: 12.5px; color: color-mix(in srgb, var(--ink-2) 82%, transparent); }

/* ---------- 子页面 ---------- */
.page-head { padding: calc(var(--nav-h) + 104px) 0 64px; }
.page-head h1 { font-size: clamp(36px, 5vw, 56px); }
.page-head .lead { margin-top: 22px; }
.page-head .lead a { color: var(--accent); }

.prose { max-width: 720px; }
.prose h2 { font-size: clamp(24px, 3vw, 30px); margin: 56px 0 18px; }
.prose p, .prose li { color: var(--ink-2); font-size: 16px; }
.prose p { margin-bottom: 14px; }
.prose p a { color: var(--accent); }
.prose ul { padding-left: 22px; display: grid; gap: 8px; margin: 10px 0 18px; }

/* FAQ：细线折叠行，不用卡片 */
.faq { margin-top: 8px; border-top: 1px solid var(--hair); }
.faq details { border-bottom: 1px solid var(--hair); padding: 22px 2px; }
.faq summary {
  font-weight: 600; font-size: 16.5px; cursor: pointer; list-style: none;
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
  color: var(--ink);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; font-size: 22px; color: var(--accent); font-weight: 400;
  transition: transform 0.25s; flex-shrink: 0;
}
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { margin-top: 14px; max-width: 40em; }

/* 下载页 */
.dl-hero { padding: calc(var(--nav-h) + 96px) 0 72px; text-align: center; }
.dl-hero .appicon { width: 112px; height: 112px; border-radius: 26px; margin: 0 auto 30px; box-shadow: var(--shadow-shot); }
.dl-hero h1 { font-size: clamp(34px, 4.6vw, 52px); }
.dl-hero .lead { margin: 20px auto 0; }
.soon-pill {
  display: inline-flex; align-items: center; gap: 9px; margin-top: 30px;
  background: color-mix(in srgb, var(--accent) 9%, transparent);
  color: var(--accent); font-weight: 600; font-size: 14.5px;
  padding: 10px 20px; border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
}
.soon-pill .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); animation: pulse 1.8s ease-in-out infinite; }
@keyframes pulse { 0%, 100% { opacity: 1; transform: scale(1); } 50% { opacity: 0.45; transform: scale(0.82); } }
.req-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 44px; }
.req-grid h3 { font-size: 14px; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent); margin-bottom: 12px; }
.req-grid p { font-size: 15px; color: var(--ink-2); }
.dl-back { text-align: center; margin-top: 72px; }

/* ---------- 动效 ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.2, 0.8, 0.2, 1); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
  .soon-pill .dot { animation: none; }
  .hero .shot { transition: none; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .nav-links { display: none; }
  .hero { padding: 130px 0 80px; }
  .hero-grid, .duet { grid-template-columns: 1fr; gap: 52px; }
  .duet .copy { order: 1; }
  .duet .shots { order: 2; }
  .hero .shot, .duet .shots .shot { max-width: 300px; margin: 0 auto; }
  .steps { grid-template-columns: 1fr; gap: 38px; margin-top: 52px; }
  .step { padding: 0; border-left: 0; }
  .plain { grid-template-columns: 1fr; gap: 30px; margin-top: 48px; }
  .req-grid { grid-template-columns: 1fr; gap: 34px; }
  .sect { padding: 80px 0; }
  .end { padding: 96px 0; }
  .page-head { padding: calc(var(--nav-h) + 72px) 0 48px; }
  .dl-hero { padding: calc(var(--nav-h) + 72px) 0 56px; }
  .foot-top { flex-direction: column; gap: 24px; }
}