/* ═══════════════════════════════════════════════════════════
   广中小悠 · v3「纸志编辑部」
   暖纸底 + 宋体标题 + 校徽红单一强调；编辑部/校刊质感。
   品牌底线不变：岩石黑按钮；红只做点缀与印章，不用渐变。
   ═══════════════════════════════════════════════════════════ */

:root {
  --ink: #17161F;
  --ink-hover: #2B2935;
  --ink-rgb: 23, 22, 31;
  --seal: #C8101E;          /* 校徽红，唯一强调色 */
  --seal-rgb: 200, 16, 30;
  --paper: #FAF6EF;
  --paper-2: #F4EFE5;
  --line: #E7E0D3;
  --line-strong: #D8CFBC;
  --text-1: #1C1A16;
  --text-2: #56534A;
  --text-3: #98948A;
  --mint: #12A594;
  --live: #EAB308;
  --font-sans: -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", Roboto, Inter, sans-serif;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", "SimSun", serif;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --shadow-card: 0 2px 8px rgba(87, 74, 46, 0.06), 0 1px 2px rgba(87, 74, 46, 0.05);
  --shadow-lift: 0 8px 24px rgba(87, 74, 46, 0.12), 0 2px 6px rgba(87, 74, 46, 0.07);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background:
    radial-gradient(rgba(87, 74, 46, 0.035) 1px, transparent 1.2px) 0 0 / 22px 22px,
    var(--paper);
  color: var(--text-1);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
::selection { background: rgba(var(--seal-rgb), 0.14); color: var(--text-1); }
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
:focus-visible { outline: 2px solid rgba(var(--seal-rgb), 0.6); outline-offset: 2px; border-radius: 4px; }
section { scroll-margin-top: 84px; }
.ic { width: 1.15em; height: 1.15em; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; flex: none; }
.ic-lg { width: 1.6em; height: 1.6em; }

.accent { color: var(--seal); }

.progress-hairline { position: fixed; inset: 0 0 auto 0; height: 2px; z-index: 120; pointer-events: none; }
.progress-hairline span { display: block; height: 100%; background: var(--seal); transform: scaleX(0); transform-origin: 0 50%; }

/* ── 导航 ──────────────────────────────────────────────── */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  background: rgba(250, 246, 239, 0.86);
  -webkit-backdrop-filter: blur(14px) saturate(1.3);
  backdrop-filter: blur(14px) saturate(1.3);
  border-bottom: 1px solid var(--line);
  transition: box-shadow 0.35s var(--ease);
}
.nav.scrolled { box-shadow: 0 8px 26px rgba(87, 74, 46, 0.09); }
.nav-inner { max-width: 1180px; margin: 0 auto; padding: 0 28px; height: 62px; display: flex; align-items: center; gap: 28px; }
.brand { display: flex; align-items: center; gap: 10px; flex: none; }
.brand-emblem { width: 28px; height: 28px; }
.brand-name { font-family: var(--font-serif); font-size: 18px; font-weight: 700; letter-spacing: 0.04em; }
.brand-badge { font-size: 11px; color: var(--text-2); background: #fff; border: 1px solid var(--line); border-radius: 4px; padding: 2.5px 9px; letter-spacing: 0.06em; white-space: nowrap; }
.nav-links { display: flex; gap: 2px; margin-left: auto; }
.nav-links a { font-size: 13.5px; color: var(--text-2); padding: 7px 13px; border-radius: 6px; transition: color 0.2s, background 0.25s var(--ease); }
.nav-links a:hover { color: var(--text-1); background: rgba(87, 74, 46, 0.06); }
.nav-links a.is-active { color: var(--seal); background: rgba(var(--seal-rgb), 0.07); }
.btn-nav { margin-left: 4px; }
@media (max-width: 860px) { .brand-badge, .nav-links { display: none; } .btn-nav { margin-left: auto; } }

/* ── 按钮：岩石黑 · 直角编辑风 ─────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: 8px; position: relative;
  border: none; cursor: pointer; font-family: inherit; font-size: 14px; font-weight: 600; letter-spacing: 0.03em;
  padding: 10px 20px; border-radius: 8px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), background 0.25s var(--ease), border-color 0.25s var(--ease), color 0.25s var(--ease);
}
.btn:active { transform: translateY(0.5px) scale(0.99); }
.btn-lg { font-size: 15.5px; padding: 14px 26px; border-radius: 9px; }
.btn-meta { font-size: 11px; font-weight: 500; opacity: 0.62; border-left: 1px solid rgba(255,255,255,.3); padding-left: 9px; margin-left: 3px; }

.btn-ink { background: var(--ink); color: #fff; box-shadow: 0 2px 6px rgba(var(--ink-rgb), 0.3); }
.btn-ink .ic { transition: transform 0.3s var(--ease); }
.btn-ink:hover { background: var(--ink-hover); transform: translateY(-1.5px); box-shadow: 0 10px 24px -6px rgba(var(--ink-rgb), 0.45); }
.btn-ink:hover .ic { transform: translateY(1.5px); }
.btn-ghost { background: transparent; color: var(--text-1); border: 1px solid var(--line-strong); }
.btn-ghost:hover { transform: translateY(-1.5px); border-color: var(--ink); box-shadow: var(--shadow-card); }
.btn-disabled { opacity: 0.5; cursor: not-allowed; background: transparent; border: 1px dashed var(--line-strong); color: var(--text-2); }

/* ── 通用标题元素 ──────────────────────────────────────── */
.eyebrow { display: inline-flex; align-items: center; gap: 9px; font-size: 12.5px; font-weight: 600; letter-spacing: 0.16em; color: var(--seal); }
.sec-idx { font-family: var(--font-serif); font-size: 11.5px; color: var(--text-2); letter-spacing: 0.1em; border: 1px solid var(--line-strong); border-radius: 4px; padding: 1px 7px; font-variant-numeric: tabular-nums; background: #fff; }
.state-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--seal); flex: none; position: relative; }
.state-dot::after { content: ""; position: absolute; inset: -3.5px; border-radius: 50%; border: 1.5px solid rgba(var(--seal-rgb), 0.45); animation: dotBreath 2.6s var(--ease) infinite; }
@keyframes dotBreath { 0%, 100% { transform: scale(0.55); opacity: 0; } 45% { transform: scale(1.15); opacity: 1; } 70% { transform: scale(1.3); opacity: 0; } }

.section { max-width: 1180px; margin: 0 auto; padding: 96px 28px 30px; }
.section-tint { max-width: none; padding-left: 0; padding-right: 0; position: relative; padding-bottom: 60px; background: linear-gradient(180deg, var(--paper-2), rgba(250, 246, 239, 0) 88%); }
.section-tint > * { max-width: 1180px; margin-left: auto; margin-right: auto; }
.section-tint .bento, .section-tint .steps, .section-tint .teacher-strip { padding: 0 28px; }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 46px; }
.section-head h2 { font-family: var(--font-serif); font-size: clamp(30px, 4vw, 44px); font-weight: 700; line-height: 1.24; margin: 12px 0 14px; letter-spacing: 0.03em; }
.section-sub { color: var(--text-2); font-size: 15.5px; }
.section-sub b { color: var(--text-1); }

html.js .reveal { opacity: 0; transform: translateY(20px); transition: opacity 0.6s var(--ease), transform 0.6s var(--ease); transition-delay: var(--d, 0s); will-change: opacity, transform; }
html.js .reveal.in { opacity: 1; transform: none; }

/* ══════════════ HERO · 封面 ══════════════ */
.hero { position: relative; padding: 150px 0 60px; overflow: clip; }
.hero-inner { max-width: 1180px; margin: 0 auto; padding: 0 28px; display: grid; grid-template-columns: 1.08fr 0.92fr; gap: 36px; align-items: center; position: relative; }
.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(42px, 5.4vw, 66px); font-weight: 700;
  line-height: 1.22; letter-spacing: 0.04em;
  margin: 18px 0 10px;
}
.hero-title em { font-style: normal; color: var(--seal); position: relative; }
.hero-title em::after {
  content: ""; position: absolute; left: 2%; right: 2%; bottom: 0.08em; height: 0.14em;
  background: rgba(var(--seal-rgb), 0.22); z-index: -1;
}
.hero-slogan { font-family: var(--font-serif); font-size: 15px; color: var(--text-2); letter-spacing: 0.14em; margin-bottom: 18px; }
.hero-sub { font-size: 16px; color: var(--text-2); max-width: 30em; }
.hero-sub b { color: var(--text-1); }
.hero-cta { display: flex; flex-wrap: wrap; align-items: center; gap: 14px; margin: 30px 0 26px; }
.hero-trust { display: flex; flex-wrap: wrap; gap: 8px 22px; list-style: none; color: var(--text-2); font-size: 13px; }
.hero-trust li { display: inline-flex; align-items: center; gap: 6px; }
.hero-trust .ic { color: var(--mint); width: 1em; height: 1em; stroke-width: 2.1; }
.hero-rule { display: block; max-width: 1180px; margin: 46px auto 0; height: 1px; background: var(--line-strong); position: relative; }
.hero-rule::before, .hero-rule::after { content: ""; position: absolute; top: -2.5px; width: 6px; height: 6px; border-radius: 50%; background: var(--seal); }
.hero-rule::before { left: 0; } .hero-rule::after { right: 0; }

/* ── 拍立得资料卡 ──────────────────────────────────────── */
.hero-shelf { position: relative; height: 520px; }
.polaroid {
  position: absolute; background: #fff;
  border: 1px solid var(--line);
  padding: 12px 12px 12px;
  box-shadow: 0 10px 30px -10px rgba(87, 74, 46, 0.28), 0 2px 6px rgba(87, 74, 46, 0.1);
  rotate: var(--rot, 0deg);
  transition: rotate 0.5s var(--ease), translate 0.5s var(--ease), box-shadow 0.5s var(--ease);
}
.polaroid:hover { rotate: 0deg; translate: 0 -6px; box-shadow: 0 18px 40px -12px rgba(87, 74, 46, 0.35); z-index: 5; }
.polaroid img { width: 100%; aspect-ratio: 1; object-fit: cover; background: var(--paper-2); }
.polaroid figcaption { font-size: 12px; color: var(--text-2); padding-top: 10px; line-height: 1.7; }
.polaroid figcaption b { color: var(--text-1); }
.po-main { width: 250px; left: 50%; top: 50%; translate: -50% -50%; z-index: 3; }
.po-left { width: 176px; left: 2%; top: 5%; z-index: 2; }
.po-right { width: 176px; right: 2%; top: 8%; z-index: 2; }

.tape { position: absolute; width: 92px; height: 26px; background: rgba(222, 205, 160, 0.55); box-shadow: 0 1px 2px rgba(87, 74, 46, 0.12); }
.tape-a { top: -12px; left: 50%; translate: -50%; rotate: -3deg; }
.tape-b { top: -12px; right: 18px; rotate: 6deg; }

.seal {
  position: absolute; right: -18px; bottom: 30px;
  font-family: var(--font-serif); font-size: 14px; font-weight: 700; letter-spacing: 0.22em;
  color: var(--seal); border: 2.5px solid var(--seal);
  padding: 7px 14px 7px 17px; border-radius: 999px;
  rotate: 9deg; opacity: 0.88;
  background: rgba(250, 246, 239, 0.85);
  box-shadow: 0 2px 8px rgba(var(--seal-rgb), 0.18);
}
.shelf-note {
  position: absolute; left: 50%; bottom: 4%; translate: -50%;
  font-size: 11.5px; letter-spacing: 0.3em; color: var(--text-3);
  border-top: 1px solid var(--line-strong);
  padding-top: 10px; white-space: nowrap;
}

/* ── 成员名录走马灯 ────────────────────────────────────── */
.ticker { border-block: 1px solid var(--line); background: #FFFDF8; overflow: hidden; }
.ticker-track { display: flex; align-items: center; gap: 26px; width: max-content; padding: 13px 0; animation: tickerMove 42s linear infinite; }
.ticker-track span { font-family: var(--font-serif); font-size: 13.5px; letter-spacing: 0.14em; color: var(--text-2); white-space: nowrap; }
.ticker-track i { width: 5px; height: 5px; border-radius: 50%; background: var(--seal); opacity: 0.55; flex: none; }
@keyframes tickerMove { to { transform: translateX(-50%); } }

/* ── 数据条 ────────────────────────────────────────────── */
.stats { padding: 44px 28px 0; }
.stats-inner { max-width: 1020px; margin: 0 auto; display: grid; grid-template-columns: repeat(4, 1fr); padding: 8px 0; }
.stat { text-align: center; display: flex; flex-direction: column; gap: 2px; padding: 14px 10px; }
.stat + .stat { border-left: 1px solid var(--line); }
.stat-num { font-family: var(--font-serif); font-size: 40px; font-weight: 700; line-height: 1.15; font-variant-numeric: tabular-nums; color: var(--text-1); }
.stat span { font-size: 12.5px; color: var(--text-2); letter-spacing: 0.08em; }
@media (max-width: 720px) {
  .stats-inner { grid-template-columns: repeat(2, 1fr); }
  .stat:nth-child(3) { border-left: none; }
  .stat-num { font-size: 30px; }
}

/* ── 成员名录 ──────────────────────────────────────────── */
.filter-bar { display: flex; justify-content: center; gap: 10px; margin-bottom: 34px; flex-wrap: wrap; }
.chip { font-family: inherit; font-size: 13.5px; font-weight: 600; cursor: pointer; color: var(--text-2); background: #fff; border: 1px solid var(--line-strong); border-radius: 8px; padding: 8px 20px; transition: all 0.28s var(--ease); }
.chip:hover { border-color: var(--ink); color: var(--text-1); }
.chip.is-active { background: var(--ink); border-color: var(--ink); color: #fff; }

.member-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
@media (max-width: 1020px) { .member-grid { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 760px) { .member-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 460px) { .member-grid { grid-template-columns: 1fr; } }

.member-card {
  position: relative; background: #fff; border: 1px solid var(--line);
  border-radius: 10px; padding: 14px 16px 16px; overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease), border-color 0.4s var(--ease);
}
.member-card.hidden { display: none; }
.member-card::after { content: ""; position: absolute; left: 12px; right: 12px; bottom: 12px; height: 1px; background: var(--line); }
.member-card::before { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px; background: var(--text-1); opacity: 0; transition: opacity 0.3s var(--ease); }
.member-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lift); border-color: var(--line-strong); }
.member-card:hover::before { opacity: 1; }
.member-bust { position: relative; height: 160px; display: grid; place-items: end center; margin-bottom: 12px; }
.member-bust img { width: 84%; aspect-ratio: 1; object-fit: contain; mix-blend-mode: multiply; transition: transform 0.45s var(--ease); -webkit-user-drag: none; }
.member-card:hover .member-bust img { transform: scale(1.05) translateY(-2px); }
.member-card h3 { font-family: var(--font-serif); font-size: 16px; font-weight: 700; letter-spacing: 0.02em; position: relative; }
.member-alias { font-family: var(--font-sans); font-size: 11.5px; font-weight: 600; color: var(--text-3); margin-left: 5px; }
.member-card p { position: relative; font-size: 12.8px; color: var(--text-2); line-height: 1.62; margin: 6px 0 12px; min-height: 42px; }
.member-foot { display: flex; gap: 6px; position: relative; margin-bottom: 8px; }
.tag { font-size: 11px; font-weight: 600; color: var(--text-2); background: var(--paper-2); border: 1px solid var(--line); border-radius: 4px; padding: 2.5px 8px; letter-spacing: 0.05em; }
.tag-seal { color: var(--seal); background: rgba(var(--seal-rgb), 0.06); border-color: rgba(var(--seal-rgb), 0.35); }
.member-note { text-align: center; color: var(--text-3); font-size: 13px; margin-top: 34px; }

/* ── 工作方法 ──────────────────────────────────────────── */
.bento { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.b-wide { grid-column: span 2; }
.b-wide2 { grid-column: 1 / -1; }
@media (max-width: 920px) { .bento { grid-template-columns: 1fr 1fr; } .b-wide { grid-column: 1 / -1; } }
@media (max-width: 620px) { .bento { grid-template-columns: 1fr; } .b-wide, .b-wide2 { grid-column: auto; } }

.bento-card { position: relative; overflow: hidden; background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 26px; box-shadow: var(--shadow-card); transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease); }
.bento-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lift); }
.bento-card h3 { font-family: var(--font-serif); font-size: 17.5px; font-weight: 700; margin-bottom: 8px; letter-spacing: 0.02em; }
.bento-card p { font-size: 13.8px; color: var(--text-2); }
.bento-copy { max-width: 34em; position: relative; }
.b-wide { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 26px; align-items: center; }
@media (max-width: 920px) { .b-wide { grid-template-columns: 1fr; } }

.bento-idx {
  font-family: var(--font-serif); font-size: 15px; font-weight: 700;
  color: var(--seal); border: 1.5px solid rgba(var(--seal-rgb), 0.5);
  width: 34px; height: 34px; display: grid; place-items: center;
  border-radius: 50%; margin-bottom: 16px; background: rgba(var(--seal-rgb), 0.04);
}

.runtime-badges { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 18px; position: relative; }
.rt-badge { font-size: 12.5px; font-weight: 600; color: var(--text-2); background: var(--paper-2); border: 1px solid var(--line); border-radius: 6px; padding: 6px 14px; font-variant-numeric: tabular-nums; }
.rt-badge-ink { background: var(--ink); color: #fff; border-color: var(--ink); }

.demo-chat { position: relative; background: #FFFDF8; border: 1px solid var(--line); border-radius: 10px; padding: 16px; display: flex; flex-direction: column; gap: 10px; }
.chat-line { max-width: 92%; font-size: 12.8px; line-height: 1.55; padding: 8px 12px; border-radius: 10px; }
.chat-user { align-self: flex-end; background: #fff; border: 1px solid var(--ink); color: var(--text-1); border-bottom-right-radius: 3px; }
.chat-ai { align-self: flex-start; color: var(--text-1); background: var(--paper-2); border: 1px solid var(--line); border-bottom-left-radius: 3px; }
.chat-ai b { color: var(--seal); }
.chat-delegate { align-self: flex-start; display: flex; gap: 10px; background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px; box-shadow: var(--shadow-card); max-width: 96%; }
.chat-avatar { width: 34px; height: 34px; border-radius: 8px; overflow: hidden; flex: none; background: #fff; border: 1px solid var(--line-strong); }
.chat-avatar img { width: 100%; height: 100%; object-fit: cover; mix-blend-mode: multiply; }
.chat-delegate-body { display: flex; flex-direction: column; gap: 3px; font-size: 12px; }
.chat-delegate-body b { color: var(--text-1); font-size: 12.5px; }
.chat-delegate-body > span { color: var(--text-2); }
.chat-tool { display: flex; align-items: center; gap: 6px; font-size: 11.5px; color: var(--text-2); margin-top: 4px; }
.chat-tool i { width: 6px; height: 6px; border-radius: 50%; background: var(--mint); flex: none; animation: mintPulse 2.2s var(--ease) infinite; }
@keyframes mintPulse { 0% { box-shadow: 0 0 0 0 rgba(18,165,148,.35); } 60% { box-shadow: 0 0 0 6px rgba(18,165,148,0); } 100% { box-shadow: 0 0 0 0 rgba(18,165,148,0); } }

/* ── 圆桌纪要 · 文书卡 ─────────────────────────────────── */
.rt-layout { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 44px; align-items: center; }
@media (max-width: 920px) { .rt-layout { grid-template-columns: 1fr; gap: 30px; } }
.rt-points { list-style: none; display: flex; flex-direction: column; gap: 10px; margin-top: 22px; }
.rt-points li { display: flex; align-items: center; gap: 10px; color: var(--text-2); font-size: 14.5px; }
.rt-points .ic { color: var(--mint); stroke-width: 2.1; }

.rt-doc {
  position: relative; background: #fff;
  border: 1px solid var(--line-strong);
  border-radius: 4px;
  box-shadow: 0 16px 40px -14px rgba(87, 74, 46, 0.25), 0 2px 6px rgba(87, 74, 46, 0.08);
  padding: 26px 28px 22px;
}
.rt-doc::before { content: ""; position: absolute; inset: 7px; border: 1px dashed var(--line-strong); border-radius: 2px; pointer-events: none; }
.rt-doc-head { text-align: center; padding-bottom: 14px; border-bottom: 2px solid var(--text-1); position: relative; }
.rt-doc-head::after { content: ""; position: absolute; left: 0; right: 0; bottom: -5px; height: 1px; background: var(--text-1); }
.rt-doc-no { font-size: 11px; letter-spacing: 0.24em; color: var(--text-3); }
.rt-doc-head h3 { font-family: var(--font-serif); font-size: 24px; font-weight: 700; letter-spacing: 0.12em; margin: 6px 0 4px; }
.rt-doc-head p { font-size: 13px; color: var(--text-2); }
.rt-doc-meta { display: flex; justify-content: center; padding: 14px 0 4px; }
.rt-status {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--paper-2); border: 1px solid var(--line-strong);
  border-radius: 999px; padding: 7px 15px;
  font-size: 12px; font-weight: 600; color: var(--text-2);
}
.rt-status-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--live); flex: none; animation: liveBreath 1.6s ease-in-out infinite; }
@keyframes liveBreath { 0%, 100% { box-shadow: 0 0 0 0 rgba(234,179,8,.4); opacity: 1; } 50% { box-shadow: 0 0 0 5px rgba(234,179,8,.08); opacity: 0.75; } }

.rt-doc-members { list-style: none; display: flex; flex-direction: column; gap: 4px; padding: 10px 0 6px; }
.rt-doc-members li {
  display: flex; align-items: center; gap: 12px;
  padding: 9px 10px; border-radius: 8px;
  transition: background 0.3s var(--ease);
}
.rt-doc-members li:hover { background: var(--paper-2); }
.rt-doc-members img { width: 40px; height: 40px; border-radius: 10px; object-fit: cover; mix-blend-mode: multiply; background: #fff; border: 1px solid var(--line); flex: none; }
.rt-doc-members b { font-size: 13.5px; display: block; }
.rt-doc-members span { font-size: 12px; color: var(--text-2); }
.rt-doc-members li > div { flex: 1; }
.rt-live { width: 9px; height: 9px; border-radius: 50%; background: rgb(var(--glow)); flex: none; animation: liveBreath 1.6s ease-in-out infinite; }
.rt-live-idle { background: var(--text-3); animation: none; }

.rt-doc-foot {
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 10px;
  border-top: 1px solid var(--line); padding-top: 14px; margin-top: 8px;
}
.rt-doc-sign { font-family: var(--font-serif); font-size: 13px; color: var(--text-2); letter-spacing: 0.08em; }
.rt-doc-sign b { color: var(--seal); font-size: 15px; border-bottom: 1px solid rgba(var(--seal-rgb), 0.4); }
.rt-doc-next { font-size: 12px; color: var(--text-3); }

/* ── 装订三步 ──────────────────────────────────────────── */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
@media (max-width: 820px) { .steps { grid-template-columns: 1fr; } }
.step { position: relative; overflow: hidden; background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 26px; box-shadow: var(--shadow-card); transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease); }
.step:hover { transform: translateY(-4px); box-shadow: var(--shadow-lift); }
.step-no { font-family: var(--font-serif); font-size: 38px; font-weight: 700; line-height: 1; color: var(--seal); display: block; margin-bottom: 14px; }
.step h3 { font-family: var(--font-serif); font-size: 16.5px; font-weight: 700; margin-bottom: 8px; }
.step p { font-size: 13.5px; color: var(--text-2); }
.teacher-strip { display: flex; gap: 16px; align-items: flex-start; background: #fff; border: 1px solid var(--line-strong); border-left: 4px solid var(--seal); border-radius: 8px; padding: 18px 22px; margin-top: 22px; }
.teacher-strip-icon { width: 40px; height: 40px; border-radius: 10px; flex: none; display: grid; place-items: center; background: var(--paper-2); color: var(--seal); border: 1px solid var(--line); }
.teacher-strip-icon .ic { width: 20px; height: 20px; }
.teacher-strip p { font-size: 13.5px; color: var(--text-2); }
.teacher-strip b { color: var(--text-1); }

/* ── 下载 · 装订单 ─────────────────────────────────────── */
#download { padding-bottom: 110px; }
.dl-wrap {
  position: relative; border: 2px solid var(--ink); border-radius: 6px;
  background: #FFFDF8;
  padding: 64px 28px 52px;
  text-align: center;
  box-shadow: 6px 6px 0 rgba(23, 22, 31, 0.12);
}
.dl-wrap::before { content: ""; position: absolute; inset: 9px; border: 1px dashed var(--line-strong); pointer-events: none; border-radius: 3px; }
.dl-head { position: relative; margin-bottom: 40px; }
.dl-cards { position: relative; display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 16px; max-width: 860px; margin: 0 auto; text-align: left; }
@media (max-width: 760px) { .dl-cards { grid-template-columns: 1fr; } }
.dl-card { background: #fff; border: 1px solid var(--line-strong); border-radius: 8px; padding: 24px; box-shadow: var(--shadow-card); display: flex; flex-direction: column; gap: 16px; transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease); }
.dl-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lift); }
.dl-card.is-muted { background: var(--paper-2); }
.dl-os { display: flex; align-items: center; gap: 13px; position: relative; }
.dl-os .ic-lg { color: var(--ink); }
.dl-os h3 { font-family: var(--font-serif); font-size: 17px; font-weight: 700; line-height: 1.3; }
.dl-os span { font-size: 12.5px; color: var(--text-3); }
.dl-actions { display: flex; flex-wrap: wrap; gap: 10px; position: relative; }
.dl-meta { font-size: 12px; color: var(--text-3); position: relative; }
.dl-promise { position: relative; margin-top: 30px; color: var(--text-2); font-size: 13px; display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 12px; }
.dl-sep { width: 3px; height: 3px; border-radius: 50%; background: var(--text-3); display: inline-block; }

/* ── 页脚 ──────────────────────────────────────────────── */
.footer { background: var(--ink); color: rgba(255, 255, 255, 0.72); overflow: hidden; }
.footer-inner { max-width: 1180px; margin: 0 auto; padding: 54px 28px 44px; display: flex; flex-wrap: wrap; gap: 30px 40px; align-items: flex-start; }
.footer-brand { display: flex; gap: 13px; align-items: center; }
.footer-emblem { width: 42px; height: 42px; }
.footer-brand b { color: #fff; font-family: var(--font-serif); font-size: 17px; letter-spacing: 0.06em; display: block; }
.footer-brand p { font-size: 12.5px; color: rgba(255, 255, 255, 0.55); margin-top: 2px; }
.footer-links { display: flex; gap: 6px; margin-left: auto; flex-wrap: wrap; }
.footer-links a { font-size: 13px; color: rgba(255, 255, 255, 0.66); padding: 6px 12px; border-radius: 6px; transition: color 0.2s, background 0.25s var(--ease); }
.footer-links a:hover { color: #fff; background: rgba(255, 255, 255, 0.08); }
.footer-legal { width: 100%; padding-top: 20px; border-top: 1px solid rgba(255, 255, 255, 0.12); }
.footer-legal p { font-size: 12px; color: rgba(255, 255, 255, 0.42); line-height: 1.9; }
.footer-legal a { color: inherit; text-decoration: underline; text-underline-offset: 3px; transition: opacity 0.2s; }
.footer-legal a:hover { opacity: 0.75; }
.footer-versions { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.footer-versions a { font-size: 11.5px; color: rgba(255, 255, 255, 0.6); border: 1px solid rgba(255, 255, 255, 0.18); border-radius: 4px; padding: 3px 12px; transition: all 0.25s var(--ease); }
.footer-versions a:hover { color: #fff; border-color: rgba(255, 255, 255, 0.45); background: rgba(255, 255, 255, 0.07); }

/* ── 回到顶部 ──────────────────────────────────── */
.backtop { position: fixed; right: 26px; bottom: 26px; z-index: 90; width: 44px; height: 44px; border-radius: 8px; border: none; cursor: pointer; background: var(--ink); color: #fff; display: grid; place-items: center; box-shadow: 0 10px 24px -6px rgba(var(--ink-rgb), 0.5); opacity: 0; pointer-events: none; transform: translateY(14px); transition: opacity 0.35s var(--ease), transform 0.35s var(--ease), background 0.25s; }
.backtop.show { opacity: 1; pointer-events: auto; transform: none; }
.backtop:hover { background: var(--ink-hover); }

/* ── 响应式 ────────────────────────────────────────────── */
@media (max-width: 1020px) {
  .hero-inner { grid-template-columns: 1fr; gap: 20px; }
  .hero-copy { text-align: center; }
  .hero-sub { margin: 0 auto; }
  .hero-cta { justify-content: center; }
  .hero-trust { justify-content: center; }
  .hero-shelf { height: 460px; max-width: 520px; margin: 0 auto; width: 100%; }
}
@media (max-width: 620px) {
  .section { padding: 72px 20px 24px; }
  .hero { padding-top: 118px; }
  .hero-shelf { height: 400px; }
  .po-main { width: 200px; }
  .po-left, .po-right { width: 140px; }
  .seal { right: -8px; }
  .ticker-track span { font-size: 12px; }
  .dl-wrap { padding: 46px 16px 38px; }
  .btn-lg { font-size: 14px; padding: 13px 20px; }
  .btn-meta { display: none; }
}