/* ===== 书院·墨韵 设计系统 ===== */
:root {
  --paper: #F7F3EC;        /* 宣纸暖白 */
  --paper-2: #FBF8F2;      /* 更亮的纸面（卡片） */
  --ink: #1F2328;          /* 墨黑 主文字 */
  --ink-soft: #4A4640;     /* 次级文字 */
  --ink-faint: #857F75;    /* 弱化文字 */
  --dai: #2E5B57;          /* 黛青 主色 */
  --dai-deep: #24463F;     /* 黛青深 */
  --dai-tint: #E7EEEC;     /* 黛青浅底 */
  --cinnabar: #C0392B;     /* 朱砂 强调 */
  --cinnabar-deep: #9E2C20;
  --line: #E1D9CB;         /* 界格线 */
  --line-soft: #ECE5D8;
  --shadow: 0 6px 24px rgba(31, 35, 40, 0.08);
  --shadow-sm: 0 2px 8px rgba(31, 35, 40, 0.06);
  --radius: 6px;
  --maxw: 1120px;
  --serif: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", "SimSun", Georgia, serif;
  --sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC", "Hiragino Sans GB", system-ui, sans-serif;
  --mono: "SFMono-Regular", "JetBrains Mono", Consolas, "Courier New", monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  color: var(--ink);
  background-color: var(--paper);
  /* 纸纹 + 淡墨晕染氛围 */
  background-image:
    radial-gradient(1100px 480px at 82% -6%, rgba(46, 91, 87, 0.10), transparent 60%),
    radial-gradient(760px 420px at -8% 8%, rgba(192, 57, 43, 0.055), transparent 58%),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='120' height='120' filter='url(%23n)' opacity='0.028'/%3E%3C/svg%3E");
  background-attachment: fixed, fixed, fixed;
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--dai); text-decoration: none; transition: color .15s; }
a:hover { color: var(--cinnabar); }

img { max-width: 100%; display: block; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ===== 印章 Logo ===== */
.seal {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  background: var(--cinnabar);
  color: #fff;
  border-radius: 5px;
  font-family: var(--serif);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 1px;
  box-shadow: inset 0 0 0 1.5px rgba(255,255,255,.35);
  flex: none;
}

/* ===== 顶部导航 ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(247, 243, 236, 0.86);
  backdrop-filter: saturate(1.2) blur(8px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-txt { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name { font-family: var(--serif); font-size: 19px; font-weight: 700; color: var(--ink); letter-spacing: .5px; }
.brand-sub { font-size: 12px; color: var(--ink-faint); letter-spacing: 2px; }

.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-links a {
  color: var(--ink-soft);
  padding: 8px 14px;
  border-radius: var(--radius);
  font-size: 15px;
  transition: background .15s, color .15s;
}
.nav-links a:hover { background: var(--dai-tint); color: var(--dai-deep); }
.nav-links a.active { color: var(--dai-deep); font-weight: 600; }
.nav-links a.active::after {
  content: ""; display: block; height: 2px; margin-top: 4px;
  background: var(--cinnabar); border-radius: 2px;
}

.nav-toggle {
  display: none;
  background: none; border: 1px solid var(--line); border-radius: var(--radius);
  width: 40px; height: 38px; cursor: pointer; color: var(--ink);
  align-items: center; justify-content: center;
}
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after {
  content: ""; display: block; width: 18px; height: 2px; background: var(--ink); position: relative;
}
.nav-toggle span::before { position: absolute; top: -6px; }
.nav-toggle span::after { position: absolute; top: 6px; }

/* ===== 通用区块 ===== */
.section { padding: 64px 0; }
.section-tight { padding: 44px 0; }

.kicker {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; letter-spacing: 3px; color: var(--dai);
  text-transform: uppercase;
}
.kicker::before {
  content: ""; width: 22px; height: 2px; background: var(--cinnabar); display: inline-block;
}
.h-title {
  font-family: var(--serif);
  font-weight: 700;
  color: var(--ink);
  margin: 14px 0 10px;
  line-height: 1.25;
}
h1.h-title { font-size: clamp(30px, 4.4vw, 46px); }
h2.h-title { font-size: clamp(24px, 3vw, 32px); }
.lead { color: var(--ink-soft); font-size: 17px; max-width: 62ch; }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 22px; border-radius: var(--radius);
  font-size: 15px; font-weight: 600; cursor: pointer;
  border: 1px solid transparent; transition: transform .12s, box-shadow .15s, background .15s;
  font-family: var(--sans);
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--dai); color: #fff; box-shadow: var(--shadow-sm); }
.btn-primary:hover { background: var(--dai-deep); color: #fff; box-shadow: var(--shadow); }
.btn-accent { background: var(--cinnabar); color: #fff; box-shadow: var(--shadow-sm); }
.btn-accent:hover { background: var(--cinnabar-deep); color: #fff; box-shadow: var(--shadow); }
.btn-ghost { background: transparent; color: var(--dai-deep); border-color: var(--line); }
.btn-ghost:hover { background: var(--dai-tint); color: var(--dai-deep); }

/* ===== Hero ===== */
.hero { padding: 84px 0 64px; position: relative; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; align-items: center; }
.hero .lead { font-size: 18px; margin: 8px 0 26px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-badges { display: flex; gap: 22px; margin-top: 30px; flex-wrap: wrap; }
.hero-badge { display: flex; flex-direction: column; }
.hero-badge b { font-family: var(--serif); font-size: 22px; color: var(--dai-deep); }
.hero-badge span { font-size: 13px; color: var(--ink-faint); }

.hero-card {
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 26px;
  box-shadow: var(--shadow);
  position: relative;
}
.hero-card::before {
  content: "墨"; position: absolute; top: 14px; right: 18px;
  font-family: var(--serif); font-size: 88px; color: rgba(46,91,87,.06); line-height: 1; pointer-events: none;
}
.hero-card h3 { font-family: var(--serif); margin: 0 0 14px; font-size: 20px; color: var(--ink); }
.chat-preview { display: flex; flex-direction: column; gap: 12px; }
.bubble { padding: 10px 14px; border-radius: 10px; font-size: 14.5px; max-width: 86%; }
.bubble.q { align-self: flex-end; background: var(--dai); color: #fff; border-bottom-right-radius: 3px; }
.bubble.a { align-self: flex-start; background: #fff; border: 1px solid var(--line); color: var(--ink-soft); border-bottom-left-radius: 3px; }

/* ===== 卡片网格 ===== */
.grid { display: grid; gap: 20px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 24px;
  transition: transform .15s, box-shadow .15s, border-color .15s;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--dai); }
.card .ic {
  width: 42px; height: 42px; border-radius: 9px;
  background: var(--dai-tint); color: var(--dai-deep);
  display: flex; align-items: center; justify-content: center; margin-bottom: 14px;
}
.card h3 { font-family: var(--serif); font-size: 18px; margin: 0 0 8px; color: var(--ink); }
.card p { margin: 0; color: var(--ink-soft); font-size: 14.5px; }

/* ===== 对话入口位 ===== */
.entry {
  background: linear-gradient(135deg, var(--dai) 0%, var(--dai-deep) 100%);
  color: #fff; border-radius: 14px; padding: 40px;
  display: flex; align-items: center; justify-content: space-between; gap: 28px;
  box-shadow: var(--shadow); position: relative; overflow: hidden;
}
.entry::after {
  content: ""; position: absolute; right: -40px; top: -40px; width: 220px; height: 220px;
  background: radial-gradient(circle, rgba(255,255,255,.12), transparent 70%);
}
.entry h2 { font-family: var(--serif); margin: 0 0 8px; font-size: 26px; color: #fff; }
.entry p { margin: 0; color: rgba(255,255,255,.85); max-width: 52ch; }
.entry .tag {
  display: inline-block; margin-top: 12px; font-size: 12px; letter-spacing: 1px;
  border: 1px dashed rgba(255,255,255,.5); padding: 3px 10px; border-radius: 20px; color: rgba(255,255,255,.9);
}

/* ===== FAQ ===== */
.faq-item { border-bottom: 1px solid var(--line); }
.faq-q {
  width: 100%; text-align: left; background: none; border: none; cursor: pointer;
  padding: 18px 4px; font-size: 16.5px; font-weight: 600; color: var(--ink);
  display: flex; justify-content: space-between; align-items: center; gap: 12px; font-family: var(--sans);
}
.faq-q .mark { color: var(--cinnabar); font-size: 22px; transition: transform .2s; line-height: 1; }
.faq-item.open .faq-q .mark { transform: rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .25s ease; color: var(--ink-soft); }
.faq-a p { margin: 0 4px 18px; }

/* ===== 对话页嵌入位 ===== */
.embed-slot {
  aspect-ratio: 16 / 9; width: 100%;
  border: 2px dashed var(--line); border-radius: 12px;
  background: var(--paper-2);
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 14px;
  text-align: center; color: var(--ink-faint); padding: 24px;
}
.embed-slot .ic { color: var(--dai); }

/* ===== 知识库 ===== */
.kb-search { display: flex; gap: 10px; max-width: 640px; }
.kb-search input {
  flex: 1; padding: 13px 16px; border: 1px solid var(--line); border-radius: var(--radius);
  font-size: 16px; background: var(--paper-2); color: var(--ink); font-family: var(--serif);
}
.kb-search input:focus { outline: none; border-color: var(--dai); box-shadow: 0 0 0 3px var(--dai-tint); }
.kb-cats { display: flex; flex-wrap: wrap; gap: 10px; margin: 22px 0 8px; }
.kb-cat {
  padding: 6px 14px; border: 1px solid var(--line); border-radius: 20px;
  font-size: 14px; color: var(--ink-soft); cursor: pointer; background: var(--paper-2); transition: all .15s;
}
.kb-cat:hover, .kb-cat.active { background: var(--dai); color: #fff; border-color: var(--dai); }

.kb-list { display: flex; flex-direction: column; gap: 14px; margin-top: 8px; }
.kb-row {
  background: var(--paper-2); border: 1px solid var(--line); border-radius: 10px; padding: 20px 22px;
  transition: transform .15s, box-shadow .15s, border-color .15s; display: block;
}
.kb-row:hover { transform: translateY(-2px); box-shadow: var(--shadow-sm); border-color: var(--dai); }
.kb-row h3 { font-family: var(--serif); margin: 0 0 6px; font-size: 18px; color: var(--ink); }
.kb-row p { margin: 0 0 10px; color: var(--ink-soft); font-size: 14.5px; }
.kb-meta { display: flex; gap: 14px; font-size: 12.5px; color: var(--ink-faint); }
.kb-meta .cat { color: var(--dai-deep); font-weight: 600; }
.kb-empty { color: var(--ink-faint); padding: 30px 0; }

/* ===== 文章详情 ===== */
.article { max-width: 760px; }
.article h1 { font-family: var(--serif); font-size: 32px; line-height: 1.3; margin: 0 0 12px; }
.article .a-meta { color: var(--ink-faint); font-size: 13px; margin-bottom: 26px; }
.article p { line-height: 1.9; color: var(--ink-soft); margin: 0 0 18px; }
.article h2 { font-family: var(--serif); font-size: 22px; margin: 32px 0 12px; scroll-margin-top: 80px; }
.toc {
  position: sticky; top: 88px; align-self: start;
  border-left: 2px solid var(--line); padding-left: 16px; font-size: 14px;
}
.toc b { display: block; margin-bottom: 10px; color: var(--ink); font-family: var(--serif); }
.toc a { display: block; padding: 5px 0; color: var(--ink-faint); }
.toc a:hover { color: var(--dai); }
.article-grid { display: grid; grid-template-columns: 1fr 220px; gap: 40px; align-items: start; }

/* ===== 信息块（关于页） ===== */
.info-card {
  background: var(--paper-2); border: 1px solid var(--line); border-radius: 10px; padding: 26px; margin-bottom: 18px;
}
.info-card h3 { font-family: var(--serif); margin: 0 0 10px; color: var(--ink); font-size: 19px; }
.info-card p, .info-card li { color: var(--ink-soft); }
.beian-box {
  border: 1px solid var(--dai); background: var(--dai-tint); border-radius: 10px; padding: 22px 26px;
}
.beian-box h3 { color: var(--dai-deep); }
.beian-box .row { display: flex; gap: 10px; padding: 6px 0; font-size: 15px; flex-wrap: wrap; }
.beian-box .row b { min-width: 96px; color: var(--ink); }
.placeholder { color: var(--cinnabar); font-family: var(--mono); font-size: 13.5px; }

/* ===== 页脚 ===== */
.footer {
  background: #171A1D; color: #C9C4BA; margin-top: 60px; padding: 46px 0 30px;
}
.footer a { color: #9FB6B1; }
.footer a:hover { color: #fff; }
.footer-top { display: flex; justify-content: space-between; gap: 30px; flex-wrap: wrap; margin-bottom: 26px; }
.footer .brand-name { color: #fff; }
.footer .brand-sub { color: #7d776c; }
.footer-cols { display: flex; gap: 54px; flex-wrap: wrap; }
.footer-col b { display: block; color: #fff; font-size: 14px; margin-bottom: 10px; font-family: var(--serif); }
.footer-col a { display: block; font-size: 14px; padding: 4px 0; }
.footer-beian {
  border-top: 1px solid #2b2f33; padding-top: 20px; font-size: 13px; color: #8b857b;
  display: flex; flex-wrap: wrap; gap: 8px 20px; align-items: center; justify-content: center; text-align: center;
}
.footer-beian a { color: #8b857b; }
.footer-beian a:hover { color: #fff; }
.footer-beian .sep { opacity: .4; }

/* ===== 响应式 ===== */
@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; }
  .grid-3 { grid-template-columns: 1fr 1fr; }
  .article-grid { grid-template-columns: 1fr; }
  .toc { position: static; border-left: none; border-top: 1px solid var(--line); padding: 16px 0 0; margin-bottom: 20px; }
  .nav-toggle { display: inline-flex; }
  .nav-links {
    position: absolute; top: 62px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 2px;
    background: var(--paper); border-bottom: 1px solid var(--line);
    padding: 10px 16px 16px; box-shadow: var(--shadow);
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a.active::after { display: none; }
  .entry { flex-direction: column; align-items: flex-start; }
}
@media (max-width: 560px) {
  .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .section { padding: 48px 0; }
  .hero { padding: 56px 0 44px; }
  .kb-search { flex-direction: column; }
  .kb-search .btn { justify-content: center; }
}