/* =================================================================
   AI · 童年 — 设计系统
   暖色学术报纸（warm scholarly broadsheet）
   纸张奶白 · 暖墨黑 · 松绿结构 · 赤陶 + 金盏花点缀
   字体：Fraunces（标题）· Newsreader（正文）· IBM Plex Mono（标签）
         Noto Serif SC（中文）
   ================================================================= */

/* ---------- 变量 ---------- */
:root {
  --paper:      #f4ede0;
  --paper-2:    #ece2d0;
  --paper-3:    #e4d8c1;
  --ink:        #201c16;
  --ink-2:      #564e41;
  --ink-3:      #837a68;
  --rule:       #d8cdb6;
  --rule-soft:  #e3d9c6;
  --pine:       #1e433a;
  --pine-2:     #163029;
  --pine-ink:   #ecf3ea;
  --terra:      #bf4a2f;
  --terra-deep: #9c3a23;
  --gold:       #c4861f;
  --gold-soft:  #e8c986;

  --font-display: "Fraunces", "Noto Serif SC", Georgia, "Songti SC", serif;
  --font-body:    "Newsreader", "Noto Serif SC", Georgia, "Songti SC", serif;
  --font-mono:    "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;

  --maxw: 1180px;
  --read: 720px;
  --r: 4px;
  --shadow-1: 0 1px 0 var(--rule), 0 2px 14px -8px rgba(32,28,22,.28);
  --shadow-2: 0 18px 40px -22px rgba(32,28,22,.5);
  --ease: cubic-bezier(.22,.61,.36,1);
}

/* ---------- 基础 ---------- */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background-color: var(--paper);
  background-image:
    radial-gradient(1200px 600px at 88% -8%, rgba(196,134,31,.10), transparent 60%),
    radial-gradient(900px 520px at -6% 4%, rgba(30,67,58,.08), transparent 55%);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 19px;
  line-height: 1.72;
  font-weight: 400;
  letter-spacing: .002em;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* 纸张颗粒叠加 */
body::before {
  content: "";
  position: fixed; inset: 0;
  pointer-events: none; z-index: 1;
  opacity: .5; mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.82' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.05'/%3E%3C/svg%3E");
}

img { max-width: 100%; display: block; }
a { color: var(--terra); text-decoration: none; }
a:hover { color: var(--terra-deep); }
::selection { background: var(--gold-soft); color: var(--ink); }

/* ---------- 排版 ---------- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 560;
  line-height: 1.1;
  letter-spacing: -.012em;
  color: var(--ink);
  margin: 0 0 .5em;
  font-optical-sizing: auto;
}
h2 { font-size: clamp(1.7rem, 3.6vw, 2.6rem); }
h3 { font-size: clamp(1.25rem, 2.2vw, 1.6rem); font-weight: 540; }
p { margin: 0 0 1.15em; }
strong { font-weight: 600; }
em { font-style: italic; }

.eyebrow {
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 500;
  letter-spacing: .26em;
  text-transform: uppercase;
  color: var(--terra-deep);
  margin: 0 0 1rem;
  display: flex; align-items: center; gap: .7rem;
}
.eyebrow::before {
  content: ""; width: 26px; height: 2px;
  background: var(--terra); display: inline-block;
}
.eyebrow.is-pine { color: var(--gold-soft); }
.eyebrow.is-pine::before { background: var(--gold); }

/* ---------- 布局 ---------- */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 28px; position: relative; z-index: 2; }
.read { max-width: var(--read); margin-left: auto; margin-right: auto; }
section { position: relative; z-index: 2; }
section[id], [id^="dir-"] { scroll-margin-top: 78px; }
.pad { padding: clamp(3.5rem, 8vw, 7rem) 0; }
.divider { height: 1px; background: var(--rule); border: 0; margin: 0; }

/* ---------- 顶部进度条 ---------- */
#progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0%;
  background: linear-gradient(90deg, var(--terra), var(--gold));
  z-index: 60; transition: width .1s linear;
}

/* ---------- 导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(8px);
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  border-bottom: 1px solid var(--rule);
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto; padding: .7rem 28px;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
}
.brand { display: flex; align-items: baseline; gap: .55rem; font-family: var(--font-display); }
.brand a { color: var(--ink); }
.brand .logo {
  font-weight: 600; font-size: 1.18rem; letter-spacing: -.02em;
}
.brand .dot { color: var(--terra); }
.brand .sub {
  font-family: var(--font-mono); font-size: .62rem; letter-spacing: .22em;
  text-transform: uppercase; color: var(--ink-3); font-weight: 500;
}
.nav-links { display: flex; align-items: center; gap: .3rem; flex-wrap: wrap; }
.nav-links a {
  font-family: var(--font-mono); font-size: .74rem; letter-spacing: .04em;
  color: var(--ink-2); padding: .42rem .62rem; border-radius: var(--r);
  text-transform: uppercase; transition: background .2s, color .2s;
  white-space: nowrap;
}
.nav-links a:hover { background: var(--paper-2); color: var(--ink); }
.nav-links a.active { color: var(--terra-deep); background: color-mix(in srgb, var(--terra) 12%, transparent); }
.nav-toggle { display: none; }

/* ---------- 标签 / 徽章 ---------- */
.tag {
  display: inline-flex; align-items: center; gap: .35rem;
  font-family: var(--font-mono); font-size: .66rem; letter-spacing: .06em;
  text-transform: uppercase; color: var(--ink-2);
  background: var(--paper-2); border: 1px solid var(--rule);
  padding: .2rem .5rem; border-radius: 100px; white-space: nowrap;
}
.tag.dir { cursor: pointer; }
.tag .swatch { width: 8px; height: 8px; border-radius: 2px; background: var(--terra); }
.badge {
  font-family: var(--font-mono); font-size: .6rem; letter-spacing: .08em;
  text-transform: uppercase; padding: .16rem .46rem; border-radius: 3px;
  border: 1px solid currentColor; font-weight: 500;
}
.badge.journal  { color: #2f6d4f; }
.badge.conf     { color: #246; }
.badge.preprint { color: var(--gold); }
.badge.report   { color: var(--ink-3); }
.badge.flag {
  color: var(--terra-deep); border-style: dashed;
  text-transform: none; letter-spacing: .02em;
}
.badge.oa { color: #2f6d4f; border-color: #2f6d4f; background: color-mix(in srgb, #2f6d4f 9%, transparent); }

/* 方向色（通过 data-dir 着色 .swatch / 边框） */
[data-dir="tutoring"]     { --c: #2f6d4f; }
[data-dir="literacy"]     { --c: #b8761b; }
[data-dir="interaction"]  { --c: #2a6f7a; }
[data-dir="mental-health"]{ --c: #b0492f; }
[data-dir="safety"]       { --c: #7d4a8c; }
[data-dir="pediatric"]    { --c: #b5343f; }
[data-dir="ethics"]       { --c: #355f8a; }
.swatch[data-dir]{ background: var(--c); }

/* =================================================================
   HERO
   ================================================================= */
.hero { padding: clamp(2.5rem, 7vw, 5.5rem) 0 clamp(2rem, 5vw, 3.5rem); overflow: hidden; }
.hero-grid {
  display: grid; grid-template-columns: 1.15fr .85fr; gap: clamp(1.5rem, 4vw, 3.5rem);
  align-items: center;
}
.hero-kicker {
  font-family: var(--font-mono); font-size: .76rem; letter-spacing: .22em;
  text-transform: uppercase; color: var(--terra-deep); margin-bottom: 1.4rem;
}
.hero h1 {
  font-size: clamp(2.6rem, 6.6vw, 5.1rem);
  line-height: .98; font-weight: 580; letter-spacing: -.022em; margin: 0 0 1.2rem;
}
.hero h1 .accent { color: var(--terra); font-style: italic; font-weight: 460; }
.hero h1 .pine { color: var(--pine); }
.hero .deck {
  font-size: clamp(1.05rem, 1.7vw, 1.32rem); color: var(--ink-2);
  max-width: 33ch; margin-bottom: 1.8rem; line-height: 1.55;
}
.hero-meta {
  display: flex; flex-wrap: wrap; gap: .5rem 1.4rem;
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .04em;
  color: var(--ink-3); border-top: 1px solid var(--rule); padding-top: 1.1rem;
}
.hero-meta b { color: var(--ink); font-weight: 600; }

/* 英雄图：节点星图 */
.hero-art { position: relative; }
.hero-art svg { width: 100%; height: auto; overflow: visible; }
.hero-art .float { animation: bob 7s var(--ease) infinite; }
@keyframes bob { 0%,100%{transform:translateY(0)} 50%{transform:translateY(-9px)} }

/* 统计条 */
.statbar {
  display: grid; grid-template-columns: repeat(5, 1fr);
  border: 1px solid var(--rule); border-radius: var(--r); overflow: hidden;
  background: color-mix(in srgb, var(--paper-2) 60%, transparent);
}
.statbar .cell { padding: 1.2rem 1rem; border-left: 1px solid var(--rule); }
.statbar .cell:first-child { border-left: 0; }
.statbar .num {
  font-family: var(--font-display); font-size: clamp(1.7rem, 3vw, 2.4rem);
  font-weight: 580; color: var(--pine); line-height: 1; letter-spacing: -.02em;
}
.statbar .lab {
  font-family: var(--font-mono); font-size: .64rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--ink-3); margin-top: .5rem;
}

/* =================================================================
   正文散文（Medium 风）
   ================================================================= */
.prose { font-size: 1.12rem; line-height: 1.78; color: #2a251d; }
.prose p { margin: 0 0 1.3em; }
.prose .lead { font-size: 1.32rem; line-height: 1.6; color: var(--ink); }
.prose .dropcap::first-letter {
  font-family: var(--font-display); font-weight: 600;
  float: left; font-size: 4.1rem; line-height: .78;
  padding: .34rem .55rem .1rem 0; color: var(--terra);
}
.prose a { box-shadow: inset 0 -.45em 0 var(--gold-soft); transition: box-shadow .2s; }
.prose a:hover { box-shadow: inset 0 -1.1em 0 var(--gold-soft); }
.prose h3 { margin-top: 2.2em; }
.mark { background: linear-gradient(180deg, transparent 62%, var(--gold-soft) 62%); padding: 0 .04em; }

.callout {
  border-left: 3px solid var(--terra); background: color-mix(in srgb, var(--paper-2) 70%, transparent);
  padding: 1.1rem 1.3rem; margin: 1.8rem 0; border-radius: 0 var(--r) var(--r) 0;
  font-size: 1.02rem; color: var(--ink-2);
}
.callout b { color: var(--ink); }

.pullquote {
  font-family: var(--font-display); font-size: clamp(1.4rem, 2.6vw, 1.9rem);
  line-height: 1.32; color: var(--pine); font-weight: 480;
  border-top: 2px solid var(--rule); border-bottom: 2px solid var(--rule);
  padding: 1.4rem 0; margin: 2.2rem 0; font-style: italic;
}

/* 章节标题块 */
.section-head { margin-bottom: 2.6rem; }
.section-head h2 { margin-bottom: .5rem; }
.section-head .sub { color: var(--ink-2); font-size: 1.1rem; max-width: 60ch; }
.section-head .idx {
  font-family: var(--font-mono); color: var(--ink-3); font-size: .8rem;
  letter-spacing: .1em;
}

/* =================================================================
   卡片网格 / 组件
   ================================================================= */
.grid { display: grid; gap: 1.2rem; }
.g-2 { grid-template-columns: repeat(2, 1fr); }
.g-3 { grid-template-columns: repeat(3, 1fr); }

.card {
  background: color-mix(in srgb, var(--paper-2) 55%, #fff 8%);
  border: 1px solid var(--rule); border-radius: var(--r);
  padding: 1.5rem 1.5rem 1.4rem; position: relative;
  transition: transform .28s var(--ease), box-shadow .28s var(--ease), border-color .2s;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-2); border-color: var(--ink-3); }

/* 方向卡 */
.dir-card { display: flex; flex-direction: column; min-height: 100%; border-top: 3px solid var(--c); }
.dir-card .num {
  font-family: var(--font-display); font-size: 2.6rem; font-weight: 560;
  color: var(--c); line-height: 1; opacity: .9;
}
.dir-card .zh { font-family: var(--font-display); font-size: 1.42rem; font-weight: 560; margin: .5rem 0 .15rem; }
.dir-card .en { font-family: var(--font-mono); font-size: .72rem; letter-spacing: .04em; color: var(--ink-3); text-transform: uppercase; }
.dir-card .tagline { color: var(--terra-deep); font-style: italic; margin: .8rem 0 .4rem; font-size: 1.02rem; }
.dir-card .desc { color: var(--ink-2); font-size: .98rem; line-height: 1.62; flex: 1; }
.dir-card .leaders {
  margin-top: 1.1rem; padding-top: 1rem; border-top: 1px dashed var(--rule);
  font-family: var(--font-mono); font-size: .7rem; letter-spacing: .04em; color: var(--ink-3);
}
.dir-card .leaders b { color: var(--pine); font-family: var(--font-body); font-size: .82rem; letter-spacing: 0; }

/* 大学排行 */
.uni-list { display: flex; flex-direction: column; gap: .8rem; }
.uni {
  display: grid; grid-template-columns: 56px 1fr auto; gap: 1.2rem; align-items: start;
  background: color-mix(in srgb, var(--paper-2) 50%, #fff 6%);
  border: 1px solid var(--rule); border-radius: var(--r);
  padding: 1.3rem 1.5rem; transition: transform .25s var(--ease), box-shadow .25s var(--ease), border-color .2s;
}
.uni:hover { transform: translateX(4px); box-shadow: var(--shadow-1); border-color: var(--ink-3); }
.uni .rank {
  font-family: var(--font-display); font-size: 2.3rem; font-weight: 580;
  color: var(--ink); line-height: .9; letter-spacing: -.03em;
}
.uni.t1 .rank { color: var(--terra); }
.uni.t2 .rank { color: var(--pine); }
.uni .name { font-family: var(--font-display); font-size: 1.32rem; font-weight: 560; }
.uni .loc { font-family: var(--font-mono); font-size: .66rem; letter-spacing: .08em; color: var(--ink-3); text-transform: uppercase; margin-left: .6rem; }
.uni .blurb { color: var(--ink-2); font-size: .96rem; margin: .55rem 0 .7rem; line-height: 1.6; }
.uni .meta-row { display: flex; flex-wrap: wrap; gap: .4rem; align-items: center; }
.uni .meta-row .lbl { font-family: var(--font-mono); font-size: .62rem; letter-spacing: .1em; text-transform: uppercase; color: var(--ink-3); margin-right: .2rem; }
.dirdots { display: inline-flex; gap: 5px; align-items: center; }
.dirdots i { width: 10px; height: 10px; border-radius: 3px; display: inline-block; background: var(--c); opacity: .85; }
.uni .tier-flag {
  font-family: var(--font-mono); font-size: .6rem; letter-spacing: .12em; text-transform: uppercase;
  color: #fff; background: var(--pine); padding: .2rem .5rem; border-radius: 3px; white-space: nowrap;
}
.uni.t1 .tier-flag { background: var(--terra); }

/* 论文卡 */
.paper {
  border: 1px solid var(--rule); border-left: 3px solid var(--c); border-radius: var(--r);
  background: color-mix(in srgb, var(--paper-2) 45%, #fff 6%);
  padding: 1.3rem 1.4rem; transition: transform .25s var(--ease), box-shadow .25s var(--ease);
}
.paper:hover { transform: translateY(-3px); box-shadow: var(--shadow-2); }
.paper .ptop { display: flex; flex-wrap: wrap; gap: .45rem; align-items: center; margin-bottom: .7rem; }
.paper .ptitle { font-family: var(--font-display); font-size: 1.12rem; font-weight: 560; line-height: 1.25; margin: 0 0 .4rem; }
.paper .ptitle a { color: var(--ink); box-shadow: none; }
.paper .ptitle a:hover { color: var(--terra-deep); }
.paper .pauth { font-size: .9rem; color: var(--ink-2); margin-bottom: .15rem; }
.paper .pvenue { font-family: var(--font-mono); font-size: .7rem; letter-spacing: .03em; color: var(--ink-3); margin-bottom: .7rem; }
.paper .pvenue b { color: var(--pine); font-weight: 600; }
.paper .pfind { font-size: .96rem; color: var(--ink-2); line-height: 1.6; }
.paper .plink {
  display: inline-flex; align-items: center; gap: .3rem; margin-top: .8rem;
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .04em; color: var(--terra);
}
.paper .plink:hover { gap: .55rem; }

/* 人物卡 */
.person {
  border: 1px solid var(--rule); border-radius: var(--r);
  background: color-mix(in srgb, var(--paper-2) 50%, #fff 6%);
  padding: 1.25rem 1.3rem; transition: transform .25s var(--ease), box-shadow .25s var(--ease), border-color .2s;
}
.person:hover { transform: translateY(-3px); box-shadow: var(--shadow-2); border-color: var(--ink-3); }
.person .pname { font-family: var(--font-display); font-size: 1.18rem; font-weight: 560; }
.person .pname a { color: var(--ink); box-shadow: none; }
.person .pname a:hover { color: var(--terra-deep); }
.person .puni { font-family: var(--font-mono); font-size: .68rem; letter-spacing: .04em; color: var(--terra-deep); text-transform: uppercase; margin: .25rem 0 .6rem; }
.person .pfocus { color: var(--ink); font-size: .95rem; font-weight: 500; margin-bottom: .3rem; }
.person .pnote { color: var(--ink-2); font-size: .9rem; line-height: 1.55; }
.person .pdirs { display: flex; gap: .3rem; margin-top: .8rem; flex-wrap: wrap; }

/* 实验室卡 */
.lab {
  border: 1px solid var(--rule); border-radius: var(--r);
  background: color-mix(in srgb, var(--paper-2) 50%, #fff 6%);
  padding: 1.25rem 1.3rem; transition: transform .25s var(--ease), box-shadow .25s var(--ease), border-color .2s;
  display: flex; flex-direction: column;
}
.lab:hover { transform: translateY(-3px); box-shadow: var(--shadow-2); border-color: var(--ink-3); }
.lab .lname { font-family: var(--font-display); font-size: 1.15rem; font-weight: 560; line-height: 1.25; }
.lab .lname a { color: var(--ink); box-shadow: none; }
.lab .lname a:hover { color: var(--terra-deep); }
.lab .luni { font-family: var(--font-mono); font-size: .68rem; letter-spacing: .05em; color: var(--terra-deep); text-transform: uppercase; margin: .3rem 0 .55rem; }
.lab .llead { font-size: .9rem; color: var(--ink); margin-bottom: .25rem; }
.lab .llead span { color: var(--ink-3); }
.lab .lfocus { font-size: .92rem; color: var(--ink-2); line-height: 1.55; flex: 1; }
.lab .pdirs { display: flex; gap: .3rem; margin-top: .8rem; flex-wrap: wrap; }

/* =================================================================
   松绿深色区块
   ================================================================= */
.pine-band { background: var(--pine); color: var(--pine-ink); position: relative; }
.pine-band::after {
  content: ""; position: absolute; inset: 0; pointer-events: none; opacity: .4; mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.06'/%3E%3C/svg%3E");
}
.pine-band h2, .pine-band h3 { color: #fff; }
.pine-band p { color: #d6e2d6; }
.pine-band a { color: var(--gold-soft); box-shadow: none; }
.pine-band a:hover { color: #fff; }
.pine-band .rule { border-color: rgba(255,255,255,.16); }

.finding-list { counter-reset: f; display: grid; gap: 1.6rem; }
.finding {
  display: grid; grid-template-columns: auto 1fr; gap: 1.3rem; align-items: start;
  padding-bottom: 1.6rem; border-bottom: 1px solid rgba(255,255,255,.14);
}
.finding:last-child { border-bottom: 0; padding-bottom: 0; }
.finding .fnum {
  counter-increment: f; font-family: var(--font-mono); font-size: .8rem; color: var(--gold-soft);
  letter-spacing: .1em; padding-top: .4rem;
}
.finding .fnum::before { content: counter(f, decimal-leading-zero); }
.finding h3 { font-size: 1.3rem; margin-bottom: .4rem; }
.finding p { margin: 0; font-size: 1.02rem; }

/* =================================================================
   过滤器（论文页）
   ================================================================= */
.filterbar { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 2rem; align-items: center; }
.filterbar .flabel { font-family: var(--font-mono); font-size: .66rem; letter-spacing: .12em; text-transform: uppercase; color: var(--ink-3); margin-right: .4rem; }
.chip {
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .02em;
  border: 1px solid var(--rule); background: var(--paper-2); color: var(--ink-2);
  padding: .4rem .8rem; border-radius: 100px; cursor: pointer; transition: all .2s;
  display: inline-flex; align-items: center; gap: .4rem;
}
.chip:hover { border-color: var(--ink-3); color: var(--ink); }
.chip.active { background: var(--pine); color: #fff; border-color: var(--pine); }
.chip .swatch { width: 8px; height: 8px; border-radius: 2px; }
.count-note { font-family: var(--font-mono); font-size: .72rem; color: var(--ink-3); margin-left: auto; }

/* =================================================================
   页脚
   ================================================================= */
.foot { background: var(--pine-2); color: #cdd9cd; padding: clamp(3rem,6vw,4.5rem) 0 2.5rem; position: relative; z-index: 2; }
.foot h3 { color: #fff; }
.foot a { color: var(--gold-soft); box-shadow: none; }
.foot a:hover { color: #fff; }
.foot-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 2.5rem; margin-bottom: 2.5rem; }
.foot .ftitle { font-family: var(--font-display); font-size: 1.5rem; color: #fff; margin-bottom: .6rem; }
.foot .fmono { font-family: var(--font-mono); font-size: .7rem; letter-spacing: .1em; text-transform: uppercase; color: #8fa593; margin-bottom: .8rem; }
.foot ul { list-style: none; padding: 0; margin: 0; }
.foot li { margin-bottom: .5rem; font-size: .92rem; }
.foot .fbar { border-top: 1px solid rgba(255,255,255,.14); padding-top: 1.5rem; font-family: var(--font-mono); font-size: .68rem; letter-spacing: .04em; color: #7e9483; display: flex; flex-wrap: wrap; justify-content: space-between; gap: 1rem; }

/* 免责声明 */
.disclaimer {
  border: 1px dashed var(--rule); border-radius: var(--r); padding: 1.2rem 1.4rem;
  background: color-mix(in srgb, var(--paper-2) 40%, transparent);
  font-size: .9rem; color: var(--ink-2); line-height: 1.6;
}
.disclaimer b { color: var(--ink); }

/* =================================================================
   滚动揭示动画
   ================================================================= */
body.reveal-ready .reveal { opacity: 0; transform: translateY(22px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
body.reveal-ready .reveal.in { opacity: 1; transform: none; }
body.reveal-ready .stagger > * { opacity: 0; transform: translateY(18px); transition: opacity .6s var(--ease), transform .6s var(--ease); }
body.reveal-ready .stagger.in > * { opacity: 1; transform: none; }
body.reveal-ready .stagger.in > *:nth-child(1){transition-delay:.04s}
body.reveal-ready .stagger.in > *:nth-child(2){transition-delay:.1s}
body.reveal-ready .stagger.in > *:nth-child(3){transition-delay:.16s}
body.reveal-ready .stagger.in > *:nth-child(4){transition-delay:.22s}
body.reveal-ready .stagger.in > *:nth-child(5){transition-delay:.28s}
body.reveal-ready .stagger.in > *:nth-child(6){transition-delay:.34s}
body.reveal-ready .stagger.in > *:nth-child(7){transition-delay:.4s}
body.reveal-ready .stagger.in > *:nth-child(8){transition-delay:.46s}
@media (prefers-reduced-motion: reduce) {
  body.reveal-ready .reveal, body.reveal-ready .stagger > * { opacity: 1 !important; transform: none !important; }
}

/* 页面载入动画 */
.hero .hero-kicker, .hero h1, .hero .deck, .hero-meta, .hero-art { animation: rise .9s var(--ease) both; }
.hero h1 { animation-delay: .08s; }
.hero .deck { animation-delay: .18s; }
.hero-meta { animation-delay: .28s; }
.hero-art { animation-delay: .2s; }
@keyframes rise { from { opacity: 0; transform: translateY(26px); } to { opacity: 1; transform: none; } }
@media (prefers-reduced-motion: reduce) { .hero * { animation: none !important; } }

/* 返回顶部 / 页面间引导 */
.bigcta {
  display: inline-flex; align-items: center; gap: .6rem;
  font-family: var(--font-mono); font-size: .8rem; letter-spacing: .08em; text-transform: uppercase;
  background: var(--terra); color: #fff; padding: .85rem 1.4rem; border-radius: var(--r);
  box-shadow: none !important; transition: background .2s, transform .2s;
}
.bigcta:hover { background: var(--terra-deep); color: #fff; transform: translateX(3px); }
.bigcta.ghost { background: transparent; color: var(--ink); border: 1px solid var(--ink); }
.bigcta.ghost:hover { background: var(--ink); color: var(--paper); }

.cta-row { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 1.5rem; }

/* =================================================================
   论文卡片操作区 + 中文摘要模态框
   ================================================================= */
.paper .pen { font-size: .85rem; color: var(--ink-3); font-style: italic; margin: -.1rem 0 .55rem; line-height: 1.35; }
.paper h3.ptitle .paper-open { background: none; border: 0; padding: 0; margin: 0; cursor: pointer;
  font: inherit; color: var(--ink); text-align: left; line-height: 1.25; }
.paper h3.ptitle .paper-open:hover { color: var(--terra-deep); }
.paper .pacts { display: flex; flex-wrap: wrap; gap: .4rem 1.3rem; align-items: center; margin-top: .9rem;
  padding-top: .8rem; border-top: 1px dashed var(--rule); }
.paper .pacts .plink { margin-top: 0; }
button.plink { background: none; border: 0; padding: 0; cursor: pointer; font-family: var(--font-mono);
  font-size: .72rem; letter-spacing: .04em; color: var(--terra); display: inline-flex; align-items: center; gap: .3rem; }
button.plink:hover { gap: .55rem; color: var(--terra-deep); }
.paper .pacts .ext { color: var(--ink-3); }
.paper .pacts .ext:hover { color: var(--terra); }

.modal-open { overflow: hidden; }
.modal { position: fixed; inset: 0; z-index: 100; display: none; }
.modal.open { display: block; }
.modal .backdrop { position: absolute; inset: 0; background: rgba(24,21,16,.55); backdrop-filter: blur(3px);
  animation: fade .25s ease; }
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }
.modal .panel { position: relative; z-index: 1; max-width: 760px; margin: 5vh auto; max-height: 90vh; overflow-y: auto;
  background: var(--paper); border: 1px solid var(--rule); border-top: 4px solid var(--c, var(--terra));
  border-radius: 8px; box-shadow: 0 36px 90px -24px rgba(0,0,0,.55); padding: 2.2rem 2.4rem 1.8rem;
  animation: rise .34s var(--ease); }
.modal .x { position: sticky; top: -.4rem; float: right; margin: -.7rem -.9rem 0 1rem;
  width: 38px; height: 38px; border-radius: 50%; cursor: pointer; line-height: 1; font-size: 1rem;
  background: var(--paper-2); border: 1px solid var(--rule); color: var(--ink-2); z-index: 2; }
.modal .x:hover { background: var(--ink); color: var(--paper); }
.modal .m-badges { display: flex; flex-wrap: wrap; gap: .45rem; margin-bottom: 1rem; align-items: center; }
.modal .m-zh { font-family: var(--font-display); font-size: clamp(1.4rem, 3vw, 1.95rem); font-weight: 580;
  line-height: 1.22; margin: 0 0 .35rem; letter-spacing: -.01em; }
.modal .m-en { font-size: .96rem; color: var(--ink-3); font-style: italic; margin-bottom: 1rem; line-height: 1.4; }
.modal .m-meta { font-family: var(--font-mono); font-size: .72rem; color: var(--ink-2); letter-spacing: .01em;
  border-bottom: 1px solid var(--rule); padding-bottom: 1.1rem; margin-bottom: 1.4rem; line-height: 1.7; }
.modal .m-meta b { color: var(--pine); }
.modal .m-kicker { font-family: var(--font-mono); font-size: .66rem; letter-spacing: .14em; text-transform: uppercase;
  color: #2f6d4f; display: inline-flex; align-items: center; gap: .5rem; margin-bottom: .9rem;
  border: 1px solid #2f6d4f; background: color-mix(in srgb, #2f6d4f 8%, transparent); padding: .3rem .6rem; border-radius: 100px; }
.modal .m-srclink { font-family: var(--font-mono); font-size: .74rem; letter-spacing: .03em; color: var(--terra);
  display: inline-flex; align-items: center; gap: .3rem; }
.modal .m-srclink:hover { gap: .5rem; color: var(--terra-deep); }
.modal .m-lead { font-family: var(--font-display); font-size: 1.12rem; line-height: 1.6; color: var(--pine);
  font-weight: 480; background: color-mix(in srgb, var(--gold-soft) 16%, transparent);
  border-left: 3px solid var(--gold); border-radius: 0 var(--r) var(--r) 0; padding: .9rem 1.1rem; margin-bottom: 1.5rem; }
.modal .m-note { font-size: .85rem; color: var(--ink-2); line-height: 1.55;
  background: color-mix(in srgb, var(--paper-2) 60%, transparent); border: 1px dashed var(--rule);
  border-radius: var(--r); padding: .7rem .95rem; margin-bottom: 1.4rem; }
.modal .m-note strong { color: var(--ink); }
.modal .m-sec { margin-bottom: 1.4rem; }
.modal .m-sec h4 { font-family: var(--font-mono); font-size: .7rem; letter-spacing: .14em; text-transform: uppercase;
  color: var(--terra-deep); margin: 0 0 .55rem; display: flex; align-items: center; gap: .55rem; }
.modal .m-sec h4::before { content: ""; width: 18px; height: 2px; background: var(--terra); }
.modal .m-sec p { margin: 0; font-size: 1.05rem; line-height: 1.74; color: #2a251d; }
.modal .m-lowconf { font-size: .84rem; color: var(--ink-2); line-height: 1.55;
  background: color-mix(in srgb, var(--gold-soft) 22%, transparent); border-radius: var(--r);
  padding: .75rem .95rem; margin-bottom: 1.3rem; }
.modal .m-foot { border-top: 1px solid var(--rule); padding-top: 1.2rem; display: flex; flex-wrap: wrap;
  gap: .9rem 1.3rem; align-items: center; justify-content: space-between; }
.modal .m-foot .note { font-size: .76rem; color: var(--ink-3); max-width: 42ch; line-height: 1.5; }
@media (max-width: 680px) {
  .modal .panel { margin: 0; min-height: 100vh; max-height: 100vh; border-radius: 0; border-top-width: 4px; padding: 1.4rem 1.2rem 2rem; }
}

/* 小工具 */
.center { text-align: center; }
.mt-0 { margin-top: 0; }
.spacer { height: 1px; }

/* =================================================================
   响应式
   ================================================================= */
@media (max-width: 900px) {
  body { font-size: 18px; }
  .hero-grid { grid-template-columns: 1fr; }
  .hero-art { order: -1; max-width: 420px; }
  .g-3, .g-2 { grid-template-columns: 1fr 1fr; }
  .foot-grid { grid-template-columns: 1fr 1fr; }
  .statbar { grid-template-columns: repeat(3, 1fr); }
  .statbar .cell:nth-child(4){ border-left: 0; }
}
@media (max-width: 680px) {
  body { font-size: 17px; }
  .nav-links { position: fixed; inset: 56px 0 auto 0; flex-direction: column; align-items: stretch;
    background: var(--paper); border-bottom: 1px solid var(--rule); padding: .6rem 18px 1rem;
    gap: 0; transform: translateY(-130%); transition: transform .32s var(--ease); box-shadow: var(--shadow-2); }
  .nav-links.open { transform: none; }
  .nav-links a { padding: .8rem .4rem; border-bottom: 1px solid var(--rule-soft); font-size: .82rem; }
  .nav-toggle { display: inline-flex; flex-direction: column; gap: 4px; background: none; border: 0; cursor: pointer; padding: .4rem; }
  .nav-toggle span { width: 22px; height: 2px; background: var(--ink); transition: .25s; }
  .nav-toggle.open span:nth-child(1){ transform: translateY(6px) rotate(45deg); }
  .nav-toggle.open span:nth-child(2){ opacity: 0; }
  .nav-toggle.open span:nth-child(3){ transform: translateY(-6px) rotate(-45deg); }
  .g-3, .g-2 { grid-template-columns: 1fr; }
  .foot-grid { grid-template-columns: 1fr; gap: 1.6rem; }
  .statbar { grid-template-columns: repeat(2, 1fr); }
  .statbar .cell { border-left: 0; border-top: 1px solid var(--rule); }
  .uni { grid-template-columns: 44px 1fr; }
  .uni .tier-flag { display: none; }
  .finding { grid-template-columns: 1fr; gap: .4rem; }
  .prose .dropcap::first-letter { font-size: 3.2rem; }
}