/* ==========================================================================
   《淮北县域小学数学跨学科多元评价体系构建》官方宣传站
   样式表 · 2027
   ========================================================================== */

/* ---------- 基础 ---------- */
:root {
  --paper: #fbf9f5;
  --paper-2: #f4efe5;
  --paper-3: #ece5d8;
  --ink: #1b2a25;
  --ink-soft: #43544c;
  --muted: #7d8a83;
  --accent: #8d2f24;
  --accent-2: #b3574a;
  --brass: #a78a52;
  --line: #e3dccc;
  --line-strong: #d2c8b3;
  --white: #fff;
  --serif: "Songti SC", "STSong", "Source Han Serif SC", "Noto Serif CJK SC", "SimSun", serif;
  --sans: "PingFang SC", "Hiragino Sans GB", "Helvetica Neue", "Microsoft YaHei", sans-serif;
  --shadow-s: 0 2px 10px rgba(27, 42, 37, .06);
  --shadow-m: 0 12px 34px rgba(27, 42, 37, .10);
  --shadow-l: 0 26px 60px rgba(27, 42, 37, .16);
  --radius: 4px;
  --wrap: 1180px;
  --head-h: 68px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }

h1, h2, h3, h4 { font-family: var(--serif); font-weight: 600; margin: 0; line-height: 1.35; }

::selection { background: rgba(141, 47, 36, .16); }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 28px; }
.serif { font-family: var(--serif); }

/* ---------- 顶部导航 ---------- */
.site-head {
  position: sticky; top: 0; z-index: 90;
  background: rgba(251, 249, 245, .92);
  backdrop-filter: saturate(140%) blur(12px);
  -webkit-backdrop-filter: saturate(140%) blur(12px);
  border-bottom: 1px solid var(--line);
  transition: box-shadow .3s, background .3s;
}
.site-head.is-stuck { box-shadow: 0 6px 22px rgba(27, 42, 37, .07); background: rgba(251, 249, 245, .97); }

.head-in { height: var(--head-h); display: flex; align-items: center; gap: 26px; }

.brand { display: flex; align-items: center; gap: 12px; flex: none; }
.brand-mark {
  width: 38px; height: 38px; flex: none;
  display: grid; place-items: center;
  background: var(--accent); color: #fff;
  font-family: var(--serif); font-size: 17px; letter-spacing: 1px;
  border-radius: 2px;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, .3), 0 3px 8px rgba(141, 47, 36, .22);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-text b { font-family: var(--serif); font-size: 16.5px; letter-spacing: .06em; font-weight: 600; }
.brand-text span { font-size: 10.5px; letter-spacing: .22em; color: var(--muted); text-transform: uppercase; }

.nav { display: flex; align-items: center; gap: 4px; margin-left: auto; }
.nav a {
  position: relative; padding: 8px 14px; font-size: 14.5px; color: var(--ink-soft);
  letter-spacing: .04em; transition: color .2s;
}
.nav a::after {
  content: ""; position: absolute; left: 14px; right: 14px; bottom: 2px; height: 1.5px;
  background: var(--accent); transform: scaleX(0); transform-origin: left; transition: transform .26s;
}
.nav a:hover { color: var(--ink); }
.nav a:hover::after, .nav a[aria-current="page"]::after { transform: scaleX(1); }
.nav a[aria-current="page"] { color: var(--ink); font-weight: 500; }

.head-tools { display: flex; align-items: center; gap: 10px; flex: none; }
.btn-quiet {
  display: inline-flex; align-items: center; gap: 7px;
  height: 36px; padding: 0 14px; border: 1px solid var(--line-strong);
  font-size: 13px; letter-spacing: .06em; color: var(--ink-soft);
  border-radius: 2px; transition: all .22s;
}
.btn-quiet:hover { border-color: var(--ink); color: var(--ink); background: #fff; }

.nav-toggle {
  display: none; width: 40px; height: 40px; border: 1px solid var(--line-strong);
  border-radius: 2px; position: relative;
}
.nav-toggle i, .nav-toggle i::before, .nav-toggle i::after {
  position: absolute; left: 11px; width: 18px; height: 1.4px; background: var(--ink); content: "";
  transition: transform .25s, opacity .2s;
}
.nav-toggle i { top: 19px; }
.nav-toggle i::before { top: -6px; left: 0; }
.nav-toggle i::after { top: 6px; left: 0; }
body.menu-open .nav-toggle i { background: transparent; }
body.menu-open .nav-toggle i::before { transform: translateY(6px) rotate(45deg); }
body.menu-open .nav-toggle i::after { transform: translateY(-6px) rotate(-45deg); }

/* 移动端抽屉 */
.drawer {
  position: fixed; inset: var(--head-h) 0 auto 0; z-index: 85;
  background: var(--paper); border-bottom: 1px solid var(--line);
  padding: 8px 0 22px; transform: translateY(-105%); transition: transform .32s cubic-bezier(.4, 0, .2, 1);
  box-shadow: var(--shadow-m);
}
body.menu-open .drawer { transform: translateY(0); }
.drawer a {
  display: block; padding: 13px 28px; font-size: 15.5px; font-family: var(--serif);
  border-bottom: 1px solid rgba(227, 220, 204, .6);
}
.drawer a:last-child { border-bottom: 0; }

/* ---------- 通用元件 ---------- */
.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 11.5px; letter-spacing: .26em; color: var(--accent);
  text-transform: uppercase; margin: 0 0 16px;
}
.eyebrow::before { content: ""; width: 26px; height: 1px; background: var(--accent); opacity: .55; }

.sec { padding: clamp(58px, 8vw, 108px) 0; }
.sec-tight { padding: clamp(40px, 5vw, 64px) 0; }
.sec-alt { background: var(--paper-2); }
.sec-head { margin-bottom: clamp(30px, 4vw, 52px); }
.sec-head h2 {
  font-size: clamp(24px, 3.2vw, 36px); letter-spacing: .04em;
}
.sec-head h2 em { font-style: normal; color: var(--accent); }
.sec-head p { margin: 14px 0 0; color: var(--ink-soft); font-size: 15px; max-width: 62ch; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  height: 48px; padding: 0 26px; font-size: 14.5px; letter-spacing: .1em;
  border-radius: 2px; transition: all .25s; white-space: nowrap;
}
.btn-primary { background: var(--accent); color: #fff; box-shadow: 0 8px 20px rgba(141, 47, 36, .22); }
.btn-primary:hover { background: #7a271e; transform: translateY(-1px); box-shadow: 0 12px 26px rgba(141, 47, 36, .28); }
.btn-ghost { border: 1px solid var(--line-strong); color: var(--ink); background: rgba(255, 255, 255, .5); }
.btn-ghost:hover { border-color: var(--ink); background: #fff; }
.btn-line { border-bottom: 1px solid var(--accent); color: var(--accent); height: auto; padding: 0 0 3px; border-radius: 0; }
.btn-line:hover { opacity: .72; }

/* ---------- 首屏 ---------- */
.hero {
  position: relative; overflow: hidden;
  padding: clamp(48px, 7vw, 92px) 0 clamp(52px, 7vw, 88px);
  background:
    radial-gradient(900px 420px at 82% 10%, rgba(167, 138, 82, .10), transparent 62%),
    radial-gradient(700px 380px at 12% 86%, rgba(141, 47, 36, .06), transparent 66%),
    var(--paper);
  border-bottom: 1px solid var(--line);
}
.hero::before {
  content: "跨"; position: absolute; right: -2vw; top: -6vh;
  font-family: var(--serif); font-size: min(46vw, 560px); line-height: 1;
  color: rgba(27, 42, 37, .028); pointer-events: none; user-select: none;
}
.hero-in { position: relative; display: grid; grid-template-columns: 1.08fr .92fr; gap: clamp(24px, 4vw, 60px); align-items: center; }

.hero-copy { max-width: 620px; }
.kicker {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 6px 12px 6px 10px; border: 1px solid var(--line-strong);
  font-size: 11.5px; letter-spacing: .18em; color: var(--ink-soft); background: rgba(255, 255, 255, .6);
  border-radius: 2px; margin-bottom: 22px;
}
.kicker b { color: var(--accent); font-weight: 600; }

.hero h1 {
  font-size: clamp(28px, 3.85vw, 45px); line-height: 1.32; letter-spacing: .02em;
  text-wrap: balance;
}
.hero h1 span { display: block; }
.hero h1 .l2 { margin-top: 4px; }
.hero-sub {
  font-family: var(--serif); font-size: clamp(15px, 1.5vw, 18px); color: var(--ink-soft);
  margin: 20px 0 0; letter-spacing: .04em;
}
.hero-sub::before { content: "——　"; color: var(--brass); }
.hero-sub::after { content: "　——"; color: var(--brass); }

.hero-meta { display: flex; flex-wrap: wrap; gap: 10px 22px; margin: 26px 0 0; font-size: 13.5px; color: var(--ink-soft); }
.hero-meta span { display: inline-flex; align-items: center; gap: 7px; }
.hero-meta i { width: 4px; height: 4px; background: var(--brass); border-radius: 50%; display: inline-block; }

.hero-acts { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }

.hero-facts { display: flex; gap: 26px; margin-top: 38px; padding-top: 22px; border-top: 1px solid var(--line); }
.hero-facts div { line-height: 1.3; }
.hero-facts b { display: block; font-family: var(--serif); font-size: 22px; font-weight: 600; }
.hero-facts span { font-size: 11.5px; color: var(--muted); letter-spacing: .12em; }

/* 立体书 */
.hero-book { display: flex; justify-content: center; perspective: 1600px; }
.book {
  position: relative; width: clamp(210px, 25vw, 306px);
  transform: rotateY(-17deg) rotateX(2.5deg); transform-style: preserve-3d;
  transition: transform .7s cubic-bezier(.2, .7, .2, 1);
}
.book:hover { transform: rotateY(-8deg) rotateX(1deg) translateY(-6px); }
.book img {
  width: 100%; border-radius: 1px 3px 3px 1px;
  box-shadow: -16px 22px 46px rgba(20, 30, 26, .30), -2px 0 0 rgba(255, 255, 255, .5) inset;
}
.book::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 15px;
  background: linear-gradient(90deg, rgba(0, 0, 0, .30), rgba(255, 255, 255, .12) 62%, rgba(0, 0, 0, .05));
  border-radius: 2px 0 0 2px; z-index: 2; mix-blend-mode: multiply;
}
.book::after {
  content: ""; position: absolute; right: -7px; top: 4px; bottom: 4px; width: 7px;
  background: repeating-linear-gradient(90deg, #f7f4ec, #e7e0d2 1px, #f7f4ec 2px, #efe9dc 3px);
  border-radius: 0 2px 2px 0; box-shadow: 3px 2px 8px rgba(20, 30, 26, .18); z-index: -1;
}
.book-shadow {
  position: absolute; left: 6%; right: -4%; bottom: -26px; height: 30px;
  background: radial-gradient(closest-side, rgba(20, 30, 26, .26), transparent 76%);
  filter: blur(6px); z-index: -2;
}
.book-tag {
  position: absolute; top: 16px; left: -14px; z-index: 3;
  background: var(--accent); color: #fff; font-size: 11px; letter-spacing: .18em;
  padding: 5px 12px 5px 10px; box-shadow: 0 6px 14px rgba(141, 47, 36, .3);
}
.book-tag::after {
  content: ""; position: absolute; right: -7px; top: 0; border: 11px solid transparent;
  border-left-color: var(--accent); border-right: 0;
}

/* ---------- 数据条 ---------- */
.stats { border-bottom: 1px solid var(--line); background: rgba(255, 255, 255, .45); }
.stats-in { display: grid; grid-template-columns: repeat(4, 1fr); }
.stats-in div {
  padding: 26px 10px; text-align: center; border-right: 1px solid var(--line);
}
.stats-in div:last-child { border-right: 0; }
.stats-in b { display: block; font-family: var(--serif); font-size: clamp(22px, 2.6vw, 30px); font-weight: 600; letter-spacing: .02em; }
.stats-in b i { font-style: normal; font-size: .55em; color: var(--muted); margin-left: 3px; }
.stats-in span { font-size: 11.5px; letter-spacing: .16em; color: var(--muted); }

/* ---------- 内容简介 ---------- */
.intro-grid { display: grid; grid-template-columns: 1.55fr .95fr; gap: clamp(28px, 5vw, 72px); align-items: start; }
.prose { font-family: var(--serif); font-size: clamp(15.5px, 1.6vw, 17.5px); line-height: 2.05; color: #26332e; }
.prose p { margin: 0 0 1.15em; text-align: justify; }
.prose p:first-of-type::first-letter {
  float: left; font-size: 3.4em; line-height: .86; padding: 6px 10px 0 0; color: var(--accent); font-weight: 600;
}
.prose .lead { color: var(--ink-soft); }

.sidecard { border: 1px solid var(--line); background: rgba(255, 255, 255, .62); padding: 26px 26px 24px; }
.sidecard h3 { font-size: 15px; letter-spacing: .1em; margin-bottom: 16px; padding-bottom: 12px; border-bottom: 1px solid var(--line); }
.dl { display: grid; grid-template-columns: 5.2em 1fr; gap: 10px 12px; font-size: 13.5px; }
.dl dt { color: var(--muted); letter-spacing: .06em; }
.dl dd { margin: 0; color: var(--ink); }
.sidecard .note { margin-top: 18px; padding-top: 14px; border-top: 1px dashed var(--line-strong); font-size: 12px; color: var(--muted); line-height: 1.7; }

/* ---------- 编辑推荐 ---------- */
.rec-grid { display: grid; gap: 1px; background: var(--line); border: 1px solid var(--line); }
.rec-grid.two { grid-template-columns: repeat(2, 1fr); }
.rec-grid.four { grid-template-columns: repeat(4, 1fr); }
.rec {
  background: var(--paper); padding: 30px 30px 32px; position: relative; transition: background .3s;
}
.rec:hover { background: #fff; }
.rec b {
  display: block; font-family: var(--serif); font-size: 13px; color: var(--brass);
  letter-spacing: .2em; margin-bottom: 12px;
}
.rec h3 { font-size: 18.5px; margin-bottom: 10px; letter-spacing: .04em; }
.rec p { margin: 0; font-size: 14px; color: var(--ink-soft); line-height: 1.85; }

/* ---------- 全书结构 ---------- */
.vol-list { border-top: 1px solid var(--line-strong); }
.vol-row {
  display: grid; grid-template-columns: 120px 1fr 190px; gap: 26px; align-items: start;
  padding: 30px 6px; border-bottom: 1px solid var(--line); transition: background .3s, padding-left .3s;
}
.vol-row:hover { background: rgba(255, 255, 255, .6); padding-left: 16px; }
.vol-no { font-family: var(--serif); font-size: 13px; letter-spacing: .2em; color: var(--accent); padding-top: 6px; }
.vol-name { font-family: var(--serif); font-size: 22px; letter-spacing: .08em; }
.vol-name small { display: block; font-family: var(--sans); font-size: 12px; letter-spacing: .1em; color: var(--muted); margin-top: 7px; }
.vol-name + .vol-desc { margin-top: 10px; }
.vol-desc { font-size: 14px; color: var(--ink-soft); line-height: 1.85; margin-top: 12px; }
.vol-ch { display: flex; flex-direction: column; align-items: flex-end; gap: 3px; padding-top: 4px; text-align: right; }
.vol-ch b { font-family: var(--serif); font-size: 14px; font-weight: 500; color: var(--ink-soft); letter-spacing: .02em; }
.vol-ch span { font-size: 11.5px; color: var(--muted); letter-spacing: .06em; }
.vol-ch a { font-size: 12px; color: var(--accent); margin-top: 8px; letter-spacing: .04em; }
.vol-ch a:hover { opacity: .7; }

/* ---------- 作者 ---------- */
.auth-grid { display: grid; grid-template-columns: 1.25fr .75fr; gap: 26px; align-items: start; }
.auth {
  background: #fff; border: 1px solid var(--line); padding: clamp(26px, 3.4vw, 40px);
  position: relative; overflow: hidden;
}
.auth::before {
  content: ""; position: absolute; inset: 0 auto 0 0; width: 3px;
  background: linear-gradient(180deg, var(--accent), rgba(141, 47, 36, 0));
}
.auth-top { display: flex; align-items: center; gap: 20px; margin-bottom: 20px; }
.avatar {
  width: 82px; height: 82px; flex: none; border-radius: 50%;
  display: grid; place-items: center; position: relative;
  background:
    radial-gradient(circle at 32% 28%, #fff, #f3ece0 68%, #e6dcc9);
  box-shadow: inset 0 0 0 1px var(--line-strong), 0 6px 18px rgba(27, 42, 37, .09);
}
.avatar span { font-family: var(--serif); font-size: 34px; color: var(--accent); font-weight: 600; }
.avatar::after {
  content: ""; position: absolute; inset: -6px; border-radius: 50%;
  border: 1px solid rgba(167, 138, 82, .38);
}
.auth-name { line-height: 1.3; }
.auth-name h3 { font-size: 24px; letter-spacing: .1em; }
.auth-name em {
  font-style: normal; display: inline-block; margin-left: 10px; vertical-align: 3px;
  font-size: 11px; letter-spacing: .14em; color: var(--accent);
  border: 1px solid rgba(141, 47, 36, .35); padding: 2px 8px; border-radius: 1px;
}
.auth-name p { margin: 8px 0 0; font-size: 13px; color: var(--muted); letter-spacing: .04em; }
.auth p { font-size: 14.5px; line-height: 1.95; color: var(--ink-soft); margin: 0 0 12px; }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin: 18px 0 0; }
.tags span {
  font-size: 12px; letter-spacing: .06em; color: var(--ink-soft);
  background: var(--paper-2); border: 1px solid var(--line); padding: 4px 11px; border-radius: 1px;
}
.auth-role { margin-top: 20px; padding-top: 16px; border-top: 1px dashed var(--line-strong); font-size: 12.5px; color: var(--muted); }
.auth-role b { color: var(--ink-soft); font-weight: 500; }

/* ---------- 目录 ---------- */
.toc { border-top: 1px solid var(--line-strong); }
.toc-vol { border-bottom: 1px solid var(--line); }
.toc-vol > summary {
  display: flex; align-items: center; gap: 16px; padding: 20px 4px; cursor: pointer; list-style: none;
}
.toc-vol > summary::-webkit-details-marker { display: none; }
.toc-vol > summary::after {
  content: "+"; margin-left: 10px; font-size: 18px; color: var(--muted); transition: transform .25s;
}
.toc-vol[open] > summary::after { content: "−"; }
.toc-vol .v-no { font-family: var(--serif); font-size: 12.5px; letter-spacing: .18em; color: var(--accent); min-width: 58px; }
.toc-vol .v-name { font-family: var(--serif); font-size: 19px; letter-spacing: .08em; }
.toc-vol .v-count { font-size: 12px; color: var(--muted); margin-left: auto; letter-spacing: .06em; }
.toc-body { padding: 0 0 22px 74px; }
.toc-ch { border-top: 1px solid rgba(227, 220, 204, .7); }
.toc-ch > summary, .toc-ch .c-row {
  display: flex; gap: 14px; align-items: baseline; padding: 13px 0; font-size: 14.5px; list-style: none;
}
.toc-ch > summary { cursor: pointer; }
.toc-ch > summary::-webkit-details-marker { display: none; }
.toc-ch > summary::after {
  content: "+"; margin-left: 8px; color: var(--muted); font-size: 13px; transition: color .2s;
}
.toc-ch[open] > summary::after { content: "−"; }
.toc-ch > summary:hover, .toc-ch > summary:hover::after { color: var(--accent); }
.toc-ch[open] > summary { color: var(--accent); }
.toc-ch .c-no { font-family: var(--serif); color: var(--ink-soft); min-width: 68px; font-size: 13px; }
.toc-ch .c-t { flex: 1; }
.toc-ch .c-n { font-size: 11.5px; color: var(--muted); letter-spacing: .06em; }
.toc-ch ul { margin: 0 0 14px; padding: 0 0 0 82px; list-style: none; }
.toc-ch ul li { font-size: 13.5px; color: var(--ink-soft); padding: 5px 0; border-bottom: 1px dotted rgba(210, 200, 179, .55); }
.toc-ch ul li:last-child { border-bottom: 0; }

/* ---------- 试读 ---------- */
.read-grid { display: grid; grid-template-columns: 250px 1fr; gap: clamp(22px, 4vw, 52px); align-items: start; }
.excerpt-grid { display: grid; grid-template-columns: 1.5fr .82fr; gap: clamp(22px, 4vw, 46px); align-items: start; }
.read-nav { position: sticky; top: calc(var(--head-h) + 22px); }
.read-nav h4 { font-size: 12px; letter-spacing: .2em; color: var(--muted); margin-bottom: 14px; }
.read-nav a {
  display: block; padding: 11px 0 11px 14px; font-size: 14px; color: var(--ink-soft);
  border-left: 2px solid var(--line); transition: all .22s;
}
.read-nav a:hover { color: var(--ink); border-left-color: var(--line-strong); }
.read-nav a.is-active { color: var(--accent); border-left-color: var(--accent); background: rgba(141, 47, 36, .04); }

.paper {
  background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow-s);
  padding: clamp(28px, 5vw, 64px);
  position: relative;
}
.paper::before {
  content: ""; position: absolute; inset: 14px; border: 1px solid rgba(210, 200, 179, .42); pointer-events: none;
}
.article { font-family: var(--serif); font-size: var(--read-size, 17px); line-height: 2.1; color: #23302b; }
.article h2 { font-size: 1.5em; letter-spacing: .05em; margin: 0 0 .4em; }
.article h3 { font-size: 1.16em; letter-spacing: .04em; margin: 1.6em 0 .6em; color: var(--accent); }
.article p { margin: 0 0 1.1em; text-indent: 2em; text-align: justify; }
.article p:first-of-type { text-indent: 0; }
.article p:first-of-type::first-letter { font-size: 2.3em; color: var(--accent); float: left; line-height: .92; padding: 3px 7px 0 0; }
.article-foot {
  display: flex; justify-content: space-between; align-items: center;
  margin-top: 30px; padding-top: 16px; border-top: 1px solid var(--line); font-size: 12px; color: var(--muted);
}
.read-tools { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-bottom: 18px; }
.read-tools .grp { display: inline-flex; border: 1px solid var(--line-strong); border-radius: 2px; overflow: hidden; }
.read-tools .grp button { padding: 7px 14px; font-size: 13px; background: #fff; }
.read-tools .grp button + button { border-left: 1px solid var(--line-strong); }
.read-tools .grp button:hover { background: var(--paper-2); }
.read-tools .hint { font-size: 12px; color: var(--muted); }

/* ---------- CTA / 购书 ---------- */
.cta {
  border: 1px solid var(--line-strong); background: linear-gradient(135deg, #fff, var(--paper-2));
  padding: clamp(30px, 4.4vw, 54px); display: grid; grid-template-columns: 1.4fr .6fr; gap: 30px; align-items: center;
}
.cta h2 { font-size: clamp(22px, 3vw, 30px); letter-spacing: .05em; }
.cta p { margin: 14px 0 0; color: var(--ink-soft); font-size: 14.5px; max-width: 54ch; }
.cta-acts { display: flex; flex-wrap: wrap; gap: 12px; justify-content: flex-end; }

/* ---------- 页脚 ---------- */
.site-foot { background: #1b2a25; color: rgba(255, 255, 255, .74); padding: clamp(46px, 6vw, 66px) 0 0; margin-top: 0; }
.foot-top { display: grid; grid-template-columns: 1.4fr .8fr .8fr 1fr; gap: 34px; padding-bottom: 42px; }
.foot-brand { display: flex; gap: 12px; align-items: flex-start; }
.foot-brand .brand-mark { background: rgba(255, 255, 255, .1); box-shadow: none; color: #fff; }
.foot-brand b { color: #fff; font-family: var(--serif); font-size: 16px; letter-spacing: .05em; }
.foot-brand p { margin: 8px 0 0; font-size: 12.5px; line-height: 1.9; color: rgba(255, 255, 255, .5); max-width: 30ch; }
.site-foot h5 { color: #fff; font-size: 12px; letter-spacing: .18em; margin: 0 0 16px; font-weight: 500; }
.site-foot ul { list-style: none; margin: 0; padding: 0; }
.site-foot li { font-size: 13px; line-height: 2.15; color: rgba(255, 255, 255, .58); }
.site-foot li a:hover { color: #fff; }
.foot-bot {
  border-top: 1px solid rgba(255, 255, 255, .1); padding: 18px 0 22px;
  display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
  font-size: 11.5px; color: rgba(255, 255, 255, .42); letter-spacing: .04em;
}

/* ---------- 子页页头 ---------- */
.page-head {
  padding: clamp(34px, 5vw, 58px) 0 clamp(26px, 3.4vw, 40px);
  border-bottom: 1px solid var(--line); background: var(--paper-2);
}
.crumb { font-size: 12px; color: var(--muted); letter-spacing: .06em; margin-bottom: 16px; }
.crumb a:hover { color: var(--accent); }
.crumb i { font-style: normal; margin: 0 8px; opacity: .5; }
.page-head h1 { font-size: clamp(26px, 4vw, 40px); letter-spacing: .05em; }
.page-head p { margin: 12px 0 0; color: var(--ink-soft); font-size: 14.5px; max-width: 66ch; }

/* ---------- 图书详情 ---------- */
.book-main { display: grid; grid-template-columns: 400px 1fr; gap: clamp(30px, 5vw, 70px); align-items: start; }
.book-visual { position: sticky; top: calc(var(--head-h) + 26px); }
.book-visual .book { width: 100%; transform: rotateY(-9deg); }
.thumbs { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin-top: 22px; }
.thumbs img {
  width: 100%; border: 1px solid var(--line); cursor: zoom-in; transition: transform .25s, border-color .25s;
  aspect-ratio: 176 / 250; object-fit: cover; background: #fff;
}
.thumbs img:hover { transform: translateY(-3px); border-color: var(--line-strong); }

.book-title h2 { font-size: clamp(26px, 3.6vw, 38px); letter-spacing: .03em; line-height: 1.32; }
.book-title .sub { font-family: var(--serif); color: var(--ink-soft); margin: 12px 0 0; font-size: 16px; }
.book-facts { display: flex; flex-wrap: wrap; gap: 8px; margin: 20px 0 0; }
.book-facts span {
  font-size: 12px; color: var(--ink-soft); border: 1px solid var(--line); padding: 4px 10px;
  background: rgba(255, 255, 255, .7);
}
.price-row { display: flex; align-items: baseline; gap: 14px; margin: 26px 0 0; }
.price-row b { font-family: var(--serif); font-size: 30px; color: var(--accent); font-weight: 600; }
.price-row b i { font-style: normal; font-size: 14px; }
.price-row span { font-size: 12.5px; color: var(--muted); }
.book-acts { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 22px; }

.spec { width: 100%; border-collapse: collapse; font-size: 13.5px; margin-top: 30px; }
.spec th, .spec td { text-align: left; padding: 11px 8px; border-bottom: 1px solid var(--line); vertical-align: top; }
.spec th { color: var(--muted); font-weight: 400; width: 6.6em; letter-spacing: .04em; }
.spec td { color: var(--ink); }

/* ---------- 作者页 ---------- */
.author-hero { display: grid; grid-template-columns: 300px 1fr; gap: clamp(26px, 4vw, 56px); align-items: start; }
.author-card-lg {
  background: #fff; border: 1px solid var(--line); padding: 32px 28px; text-align: center;
  position: sticky; top: calc(var(--head-h) + 26px);
}
.author-card-lg .avatar { width: 112px; height: 112px; margin: 0 auto 20px; }
.author-card-lg .avatar span { font-size: 46px; }
.author-card-lg h2 { font-size: 26px; letter-spacing: .12em; }
.author-card-lg .role { margin: 8px 0 0; font-size: 12.5px; color: var(--accent); letter-spacing: .12em; }
.author-card-lg .org { margin: 14px 0 0; font-size: 13px; color: var(--muted); line-height: 1.85; }
.author-card-lg .stat { display: flex; justify-content: space-around; margin-top: 22px; padding-top: 18px; border-top: 1px solid var(--line); }
.author-card-lg .stat b { display: block; font-family: var(--serif); font-size: 20px; }
.author-card-lg .stat span { font-size: 11px; color: var(--muted); letter-spacing: .1em; }

.timeline { border-left: 1px solid var(--line-strong); margin: 6px 0 0 6px; padding-left: 24px; }
.timeline li { list-style: none; position: relative; padding-bottom: 22px; }
.timeline li::before {
  content: ""; position: absolute; left: -29px; top: 7px; width: 7px; height: 7px; border-radius: 50%;
  background: var(--paper); border: 1.5px solid var(--accent);
}
.timeline b { display: block; font-family: var(--serif); font-size: 14px; letter-spacing: .06em; }
.timeline span { font-size: 13.5px; color: var(--ink-soft); line-height: 1.8; }

/* ---------- 提示 / 图片灯箱 ---------- */
.lightbox {
  position: fixed; inset: 0; z-index: 200; background: rgba(16, 24, 21, .92);
  display: none; place-items: center; padding: 30px;
}
.lightbox.on { display: grid; }
.lightbox img { max-width: min(92vw, 720px); max-height: 88vh; box-shadow: var(--shadow-l); }
.lightbox button { position: absolute; top: 22px; right: 26px; color: #fff; font-size: 26px; line-height: 1; }

/* ---------- 动效 ---------- */
.js .reveal { opacity: 0; transform: translateY(20px); transition: opacity .7s ease, transform .7s cubic-bezier(.2, .7, .2, 1); }
.js .reveal.in { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: .08s; }
.reveal.d2 { transition-delay: .16s; }
.reveal.d3 { transition-delay: .24s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .reveal { opacity: 1; transform: none; transition: none; }
  .book { transition: none; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
  .hero-in { grid-template-columns: 1fr .8fr; }
  .foot-top { grid-template-columns: 1.2fr .8fr .8fr; }
  .foot-top > div:last-child { display: none; }
  .book-main { grid-template-columns: 330px 1fr; }
}

@media (max-width: 900px) {
  :root { --head-h: 60px; }
  .wrap { padding: 0 20px; }
  .nav, .head-tools .btn-quiet { display: none; }
  .nav-toggle { display: block; margin-left: auto; }

  .hero { padding: 34px 0 44px; }
  .hero-in { grid-template-columns: 1fr; gap: 40px; }
  .hero-book { order: -1; }
  .book { width: 190px; transform: rotateY(-13deg); }
  .hero-facts { gap: 18px; }
  .hero-facts b { font-size: 19px; }

  .stats-in { grid-template-columns: repeat(2, 1fr); }
  .stats-in div:nth-child(2) { border-right: 0; }
  .stats-in div:nth-child(1), .stats-in div:nth-child(2) { border-bottom: 1px solid var(--line); }

  .intro-grid, .auth-grid, .read-grid, .author-hero, .book-main, .cta, .excerpt-grid { grid-template-columns: 1fr; }
  .read-nav, .book-visual, .author-card-lg { position: static; }
  .read-nav { display: flex; gap: 8px; overflow-x: auto; padding-bottom: 6px; margin-bottom: 4px; -webkit-overflow-scrolling: touch; }
  .read-nav a {
    border-left: 0; border: 1px solid var(--line); padding: 8px 14px; white-space: nowrap;
    font-size: 13px; border-radius: 999px;
  }
  .read-nav a.is-active { border-color: var(--accent); background: rgba(141, 47, 36, .05); }
  .read-nav h4 { display: none; }

  .rec-grid.two, .rec-grid.four { grid-template-columns: 1fr; }
  .vol-row { grid-template-columns: 1fr; gap: 10px; padding: 24px 2px; }
  .vol-ch { text-align: left; }
  .toc-body { padding-left: 8px; }
  .toc-ch ul { padding-left: 20px; }
  .cta-acts { justify-content: flex-start; }
  .book-visual .book { max-width: 240px; margin: 0 auto; }
  .thumbs { grid-template-columns: repeat(4, 1fr); }
  .foot-top { grid-template-columns: 1fr 1fr; gap: 26px; }
  .site-foot { padding-top: 40px; }
}

@media (max-width: 560px) {
  body { font-size: 15px; }
  .brand-text span { display: none; }
  .hero h1 { font-size: 27px; }
  .hero-sub { font-size: 14px; }
  .hero-acts .btn { width: 100%; }
  .hero-meta { font-size: 12.5px; gap: 8px 16px; }
  .sec { padding: 42px 0; }
  .paper { padding: 22px 18px; }
  .paper::before { inset: 8px; }
  .article { font-size: 16px; line-height: 2; }
  .stats-in b { font-size: 21px; }
  .auth { padding: 22px 18px; }
  .avatar { width: 66px; height: 66px; }
  .avatar span { font-size: 27px; }
  .auth-name h3 { font-size: 20px; }
  .rec { padding: 22px 18px; }
  .vol-name { font-size: 19px; }
  .book-title h2 { font-size: 23px; }
  .cta { padding: 24px 18px; }
  .cta-acts .btn { width: 100%; }
  .page-head { padding-top: 26px; }
  .foot-bot { flex-direction: column; gap: 6px; }
  .thumbs { grid-template-columns: repeat(2, 1fr); }
  .spec th { width: 5.2em; }
}

/* ---------- 辅助 ---------- */
[id] { scroll-margin-top: calc(var(--head-h) + 16px); }

.to-top {
  position: fixed; right: 22px; bottom: 22px; z-index: 80;
  width: 44px; height: 44px; border-radius: 50%;
  background: #fff; border: 1px solid var(--line-strong); color: var(--ink);
  box-shadow: 0 10px 24px rgba(27, 42, 37, .14);
  opacity: 0; pointer-events: none; transform: translateY(10px);
  transition: opacity .28s, transform .28s;
  font-size: 16px; line-height: 1;
}
.to-top.on { opacity: 1; pointer-events: auto; transform: none; }
.to-top:hover { background: var(--paper-2); }

@media (max-width: 560px) {
  .to-top { right: 14px; bottom: 14px; width: 40px; height: 40px; }
}

.toc-tools { display: flex; align-items: center; gap: 14px; margin-bottom: 18px; flex-wrap: wrap; }
.toc-tools input {
  flex: 1; min-width: 220px; max-width: 360px; height: 42px; padding: 0 14px;
  border: 1px solid var(--line-strong); background: #fff; border-radius: 2px;
  font: inherit; font-size: 14px; color: var(--ink); outline: none; transition: border-color .2s;
}
.toc-tools input:focus { border-color: var(--accent); }
.toc-tools input::placeholder { color: var(--muted); }
.toc-tools .hint { font-size: 12px; color: var(--muted); }