/* ============================================================
   文心织网 · 设计系统
   宣纸 / 墨 / 朱砂 / 黛青 —— 水墨文艺风
   ============================================================ */

:root {
  --paper: #f5efe3;
  --paper-deep: #ece3cf;
  --paper-card: #faf6ec;
  --ink: #26221c;
  --ink-soft: #5a554b;
  --ink-faint: #8a8375;
  --cinnabar: #b03a2e;
  --cinnabar-deep: #8f2d23;
  --indigo: #2f5d62;
  --gold: #a57c1b;
  --line: rgba(38, 34, 28, 0.14);
  --serif: "Noto Serif SC", "Songti SC", "STSong", "SimSun", serif;
  --brush: "Ma Shan Zheng", "Noto Serif SC", "Kaiti SC", "KaiTi", serif;
  --shadow-soft: 0 2px 6px rgba(38, 34, 28, 0.06), 0 12px 32px rgba(38, 34, 28, 0.08);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--serif);
  color: var(--ink);
  line-height: 1.9;
  /* 宣纸纹理：细腻纤维噪感 */
  background-color: var(--paper);
  background-image:
    radial-gradient(ellipse 80% 60% at 15% 0%, rgba(176, 58, 46, 0.035), transparent 60%),
    radial-gradient(ellipse 70% 50% at 90% 100%, rgba(47, 93, 98, 0.04), transparent 60%),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='200'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3CfeColorMatrix values='0 0 0 0 0.15 0 0 0 0 0.13 0 0 0 0 0.10 0 0 0 0.035 0'/%3E%3C/filter%3E%3Crect width='200' height='200' filter='url(%23n)'/%3E%3C/svg%3E");
  min-height: 100vh;
}

::selection { background: rgba(176, 58, 46, 0.18); }

a { color: var(--cinnabar); text-decoration: none; }
a:hover { color: var(--cinnabar-deep); }

/* ---------- 印章 ---------- */
.seal {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--brush);
  background: var(--cinnabar);
  color: #f8f2e6;
  border-radius: 6px;
  box-shadow: 2px 2px 0 rgba(38, 34, 28, 0.15);
  line-height: 1.25;
  user-select: none;
}
.seal-small { width: 34px; height: 34px; font-size: 19px; }

/* ---------- 导航 ---------- */
.nav {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px clamp(20px, 5vw, 56px);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(245, 239, 227, 0.88);
  backdrop-filter: blur(10px);
}
.nav-brand { display: flex; align-items: center; gap: 12px; color: var(--ink); }
.nav-title { font-family: var(--brush); font-size: 24px; letter-spacing: 4px; }
.nav-sub { font-size: 13px; color: var(--ink-faint); letter-spacing: 2px; margin-left: 2px; }
.nav-back { margin-left: auto; font-size: 14px; color: var(--ink-soft); border-bottom: 1px solid transparent; }
.nav-back:hover { color: var(--cinnabar); border-bottom-color: var(--cinnabar); }

/* ---------- 首页 Hero ---------- */
.hero {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(16px, 4vw, 48px);
  padding: clamp(48px, 8vw, 96px) clamp(20px, 5vw, 56px) clamp(24px, 4vw, 48px);
  max-width: 1240px;
  margin: 0 auto;
}
.hero-vertical {
  writing-mode: vertical-rl;
  font-family: var(--brush);
  font-size: clamp(15px, 1.6vw, 20px);
  letter-spacing: 14px;
  color: var(--ink-faint);
  border-right: 1px solid var(--line);
  padding-right: 18px;
  height: fit-content;
}
.hero-main { flex: 1; min-width: 0; }
.hero-kicker {
  font-size: 13px;
  letter-spacing: 4px;
  color: var(--cinnabar);
  margin-bottom: 18px;
}
.hero-kicker::before { content: "—— "; color: var(--ink-faint); }
.hero-title {
  font-size: clamp(34px, 5.2vw, 60px);
  font-weight: 900;
  line-height: 1.35;
  letter-spacing: 2px;
}
.hero-title em {
  font-style: normal;
  color: var(--cinnabar);
  position: relative;
}
.hero-title em::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 6px;
  height: 10px;
  background: linear-gradient(90deg, rgba(176,58,46,0.16), rgba(176,58,46,0.05));
  z-index: -1;
}
.hero-type {
  margin-top: 22px;
  font-size: clamp(15px, 1.8vw, 19px);
  color: var(--indigo);
  min-height: 1.9em;
  font-weight: 500;
}
.caret {
  display: inline-block;
  width: 2px; height: 1.1em;
  background: var(--indigo);
  vertical-align: -0.15em;
  margin-left: 3px;
  animation: blink 1s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }
.hero-desc { margin-top: 18px; color: var(--ink-soft); font-size: 15px; }
.hero-seal {
  width: 84px; height: 84px;
  font-size: 30px;
  flex-shrink: 0;
  transform: rotate(-4deg);
  opacity: 0.92;
}

/* ---------- 筛选条 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 8px clamp(20px, 5vw, 56px) 20px;
  max-width: 1240px;
  margin: 0 auto;
}
.filter-chip {
  font-family: var(--serif);
  font-size: 14px;
  letter-spacing: 2px;
  padding: 7px 18px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--paper-card);
  color: var(--ink-soft);
  cursor: pointer;
  transition: all 0.25s ease;
}
.filter-chip:hover { border-color: var(--cinnabar); color: var(--cinnabar); transform: translateY(-1px); }
.filter-chip.active {
  background: var(--cinnabar);
  border-color: var(--cinnabar);
  color: #f8f2e6;
  box-shadow: 0 4px 14px rgba(176, 58, 46, 0.28);
}

/* ---------- 图谱 ---------- */
.graph-wrap {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 clamp(12px, 3vw, 40px) 40px;
}
#graph {
  width: 100%;
  height: min(640px, 72vh);
  border: 1px solid var(--line);
  border-radius: 14px;
  background:
    radial-gradient(ellipse 60% 50% at 50% 40%, rgba(250, 246, 236, 0.9), rgba(236, 227, 207, 0.55));
  box-shadow: var(--shadow-soft);
  overflow: hidden;
}
.graph-hint {
  text-align: center;
  font-size: 12.5px;
  color: var(--ink-faint);
  letter-spacing: 2px;
  margin-top: 12px;
}

/* ---------- 首页页脚 ---------- */
.home-footer {
  text-align: center;
  padding: 48px 20px 56px;
  border-top: 1px solid var(--line);
  font-family: var(--brush);
  font-size: 18px;
  letter-spacing: 3px;
  color: var(--ink-soft);
}
.home-footer .dim { font-family: var(--serif); font-size: 12.5px; color: var(--ink-faint); letter-spacing: 1px; margin-top: 10px; }

/* ---------- 详情页 ---------- */
#reading-progress {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--cinnabar), var(--gold));
  z-index: 100;
  transition: width 0.1s linear;
}

.detail-hero {
  max-width: 880px;
  margin: 0 auto;
  padding: clamp(36px, 6vw, 72px) 24px 8px;
  text-align: center;
}
.detail-crumb {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 13.5px;
  letter-spacing: 3px;
  color: var(--ink-faint);
}
.detail-crumb .crumb-seal {
  font-family: var(--brush);
  color: #f8f2e6;
  background: var(--cat-color, var(--cinnabar));
  border-radius: 5px;
  padding: 2px 8px;
  letter-spacing: 2px;
  font-size: 13px;
}
.detail-title {
  font-size: clamp(30px, 4.6vw, 46px);
  font-weight: 900;
  margin: 22px 0 6px;
  letter-spacing: 2px;
}
.detail-tagline {
  font-size: clamp(15px, 2vw, 18px);
  color: var(--cat-color, var(--indigo));
  font-weight: 500;
}
.detail-rule {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin: 30px auto 0;
  color: var(--ink-faint);
}
.detail-rule::before, .detail-rule::after {
  content: "";
  height: 1px;
  width: min(160px, 26vw);
  background: linear-gradient(90deg, transparent, var(--line));
}
.detail-rule::after { background: linear-gradient(90deg, var(--line), transparent); }
.detail-rule span { font-family: var(--brush); font-size: 15px; }

.detail-body {
  max-width: 760px;
  margin: 0 auto;
  padding: 28px 24px 32px;
  font-size: 16.5px;
}
.detail-body h3 {
  font-size: 22px;
  font-weight: 700;
  margin: 42px 0 16px;
  padding-left: 14px;
  border-left: 4px solid var(--cat-color, var(--cinnabar));
  letter-spacing: 1px;
}
.detail-body h4 {
  font-size: 17.5px;
  font-weight: 700;
  margin: 26px 0 10px;
  color: var(--cat-color, var(--ink));
}
.detail-body p { margin: 14px 0; color: var(--ink); }
.detail-body ul, .detail-body ol { margin: 14px 0 14px 1.4em; }
.detail-body li { margin: 8px 0; }
.detail-body strong { color: var(--cinnabar-deep); font-weight: 700; }
.detail-body blockquote {
  margin: 20px 0;
  padding: 14px 20px;
  border-left: 3px solid var(--gold);
  background: rgba(165, 124, 27, 0.06);
  color: var(--ink-soft);
  border-radius: 0 8px 8px 0;
}

/* 名家示例卡片 */
.example-card {
  margin: 26px 0;
  background: var(--paper-card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 26px 28px 20px;
  box-shadow: var(--shadow-soft);
  position: relative;
}
.example-card::before {
  content: "「";
  position: absolute;
  top: -6px; left: 16px;
  font-family: var(--brush);
  font-size: 64px;
  color: var(--cat-color, var(--cinnabar));
  opacity: 0.28;
  line-height: 1;
}
.example-quote {
  font-size: 17px;
  line-height: 2;
  color: var(--ink);
  padding-left: 6px;
}
.example-quote em { font-style: normal; background: rgba(176, 58, 46, 0.1); padding: 0 3px; border-radius: 3px; }
.example-source {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 14px;
  font-size: 13.5px;
  color: var(--ink-faint);
  justify-content: flex-end;
}
.example-source .src-seal {
  font-family: var(--brush);
  font-size: 12px;
  color: #f8f2e6;
  background: var(--cat-color, var(--cinnabar));
  border-radius: 4px;
  padding: 1px 7px;
}
.example-analysis {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px dashed var(--line);
  font-size: 14.5px;
  color: var(--ink-soft);
}
.example-analysis::before {
  content: "✎ 技法拆解";
  display: block;
  font-weight: 700;
  color: var(--cat-color, var(--indigo));
  margin-bottom: 6px;
  letter-spacing: 2px;
  font-size: 13.5px;
}

/* 练笔作业 */
.practice-box {
  margin: 34px 0 8px;
  border: 1px dashed var(--cat-color, var(--cinnabar));
  border-radius: 12px;
  padding: 20px 24px;
  background: rgba(176, 58, 46, 0.04);
}
.practice-box::before {
  content: "✍ 练笔作业";
  display: block;
  font-weight: 700;
  color: var(--cinnabar);
  letter-spacing: 3px;
  margin-bottom: 8px;
  font-size: 14px;
}
.practice-box p { margin: 6px 0; font-size: 15px; }

/* 相关知识点 */
.related-section {
  max-width: 880px;
  margin: 0 auto;
  padding: 20px 24px 80px;
}
.related-title {
  text-align: center;
  font-family: var(--brush);
  font-size: 22px;
  letter-spacing: 6px;
  color: var(--ink-soft);
  margin: 30px 0 26px;
}
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 16px;
}
.related-card {
  display: block;
  background: var(--paper-card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 18px 20px;
  color: var(--ink);
  transition: all 0.25s ease;
  position: relative;
  overflow: hidden;
}
.related-card::after {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 3px;
  background: var(--cat-color, var(--cinnabar));
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 0.25s ease;
}
.related-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-soft);
  border-color: var(--cat-color, var(--cinnabar));
}
.related-card:hover::after { transform: scaleY(1); }
.related-card .rel-cat {
  font-size: 12px;
  letter-spacing: 2px;
  color: var(--cat-color, var(--cinnabar));
}
.related-card .rel-name { font-size: 17px; font-weight: 700; margin: 6px 0 4px; }
.related-card .rel-tag { font-size: 13px; color: var(--ink-faint); line-height: 1.7; }

/* 404 */
.notfound {
  max-width: 560px;
  margin: 0 auto;
  padding: 120px 24px;
  text-align: center;
}
.notfound h1 { font-family: var(--brush); font-size: 56px; color: var(--cinnabar); }
.notfound p { color: var(--ink-soft); margin: 16px 0 28px; }

/* ---------- 水墨转场 ---------- */
#ink-transition {
  position: fixed;
  inset: 0;
  background: var(--ink);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  clip-path: circle(0% at 50% 50%);
  pointer-events: none;
  visibility: hidden;
}
#ink-transition.play { visibility: visible; }
.ink-seal {
  font-family: var(--brush);
  font-size: 64px;
  color: rgba(245, 239, 227, 0.9);
  opacity: 0;
}

/* ---------- 动效初始态（GSAP 控制出现） ---------- */
.gs-reveal { opacity: 0; transform: translateY(26px); }

/* ---------- 响应式 ---------- */
@media (max-width: 720px) {
  .hero-vertical { display: none; }
  .hero-seal { width: 64px; height: 64px; font-size: 24px; }
  .nav-sub { display: none; }
  #graph { height: 60vh; }
  .detail-body { font-size: 15.5px; }
  .example-card { padding: 20px 18px 16px; }
}