/* ============================================================================
   Yiwei Ou — Personal Academic Website
   设计系统：暖纸白 + 学术绯红点缀；衬线标题（Source Serif 4）+ 无衬线正文（Inter）
   ============================================================================ */

:root {
  --bg: #f7f6f3;
  --surface: #ffffff;
  --surface-2: #f0eee9;
  --ink: #1e242c;
  --ink-soft: #3a424c;
  --muted: #6a7280;
  --line: #e5e1d8;
  --accent: #8c1d2f;
  --accent-hover: #6f1524;
  --accent-soft: rgba(140, 29, 47, 0.07);
  --gold: #b98a2f;
  --shadow-sm: 0 1px 2px rgba(30, 36, 44, 0.05), 0 2px 8px rgba(30, 36, 44, 0.04);
  --shadow-md: 0 4px 14px rgba(30, 36, 44, 0.08), 0 1px 4px rgba(30, 36, 44, 0.05);
  --radius: 14px;
  --serif: "Source Serif 4", "Georgia", "Times New Roman", serif;
  --sans: "Inter", -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: "JetBrains Mono", "SFMono-Regular", Consolas, monospace;
  --topnav-h: 60px;
}

html[data-theme="dark"] {
  --bg: #10141a;
  --surface: #171d25;
  --surface-2: #1e2530;
  --ink: #e8eaee;
  --ink-soft: #c6ccd4;
  --muted: #97a0ac;
  --line: #2a323d;
  --accent: #e28a97;
  --accent-hover: #efa7b1;
  --accent-soft: rgba(226, 138, 151, 0.1);
  --gold: #d4af5e;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
}

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

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--topnav-h) + 16px); }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--ink);
  font-size: 15.5px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  transition: background 0.35s ease, color 0.35s ease;
}

::selection { background: var(--accent); color: #fff; }

a { color: var(--accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--accent-hover); }

/* ---------- 顶部阅读进度条 ---------- */
.progress-bar {
  position: fixed; top: 0; left: 0; height: 2.5px; width: 0;
  background: linear-gradient(90deg, var(--accent), var(--gold));
  z-index: 1001; transition: width 0.08s linear;
}

/* ---------- 顶部导航 ---------- */
.topnav {
  position: fixed; top: 0; left: 0; right: 0; height: var(--topnav-h); z-index: 1000;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, background 0.35s;
}
.topnav.scrolled { border-bottom-color: var(--line); }
.topnav-inner {
  max-width: 1180px; margin: 0 auto; height: 100%;
  display: flex; align-items: center; gap: 28px; padding: 0 28px;
}
.brand {
  font-family: var(--serif); font-weight: 700; font-size: 19px;
  color: var(--ink); letter-spacing: 0.01em; white-space: nowrap;
}
.brand:hover { color: var(--accent); }
.nav-links { display: flex; gap: 4px; margin-left: auto; }
.nav-links a {
  position: relative; padding: 7px 11px; font-size: 13.5px; font-weight: 500;
  color: var(--muted); border-radius: 8px; letter-spacing: 0.01em;
  transition: color 0.2s, background 0.2s;
}
.nav-links a:hover { color: var(--ink); background: var(--accent-soft); }
.nav-links a.active { color: var(--accent); }
.nav-links a.active::after {
  content: ""; position: absolute; left: 11px; right: 11px; bottom: 2px;
  height: 2px; border-radius: 2px; background: var(--accent);
}
.nav-actions { display: flex; align-items: center; gap: 8px; }
.theme-toggle {
  display: grid; place-items: center; width: 34px; height: 34px;
  border: 1px solid var(--line); border-radius: 9px; background: var(--surface);
  color: var(--ink-soft); cursor: pointer; transition: all 0.25s;
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }
html[data-theme="dark"] .icon-sun { display: none; }
html:not([data-theme="dark"]) .icon-moon { display: none; }

.menu-toggle {
  display: none; flex-direction: column; justify-content: center; gap: 4.5px;
  width: 34px; height: 34px; padding: 8px;
  border: 1px solid var(--line); border-radius: 9px; background: var(--surface); cursor: pointer;
}
.menu-toggle span { display: block; height: 1.8px; background: var(--ink-soft); border-radius: 2px; transition: 0.25s; }
.menu-toggle.open span:nth-child(1) { transform: translateY(6.3px) rotate(45deg); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: translateY(-6.3px) rotate(-45deg); }

/* ---------- 整体布局 ---------- */
.layout {
  max-width: 1180px; margin: 0 auto; padding: calc(var(--topnav-h) + 40px) 28px 60px;
  display: grid; grid-template-columns: 300px minmax(0, 1fr); gap: 52px;
}

/* ---------- 左侧边栏 ---------- */
.sidebar { position: sticky; top: calc(var(--topnav-h) + 32px); align-self: start; }
.profile-card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px 26px 26px; box-shadow: var(--shadow-sm); text-align: center;
  transition: background 0.35s, border-color 0.35s;
}
.profile-photo {
  width: 158px; height: 158px; border-radius: 50%; object-fit: cover;
  border: 3px solid var(--surface); outline: 1px solid var(--line);
  box-shadow: var(--shadow-md); margin-bottom: 18px;
  transition: transform 0.35s ease;
}
.profile-photo:hover { transform: scale(1.03); }
.profile-name { font-family: var(--serif); font-size: 25px; font-weight: 700; line-height: 1.25; }
.profile-name .cn { display: block; font-size: 14.5px; font-weight: 400; color: var(--muted); margin-top: 3px; letter-spacing: 0.12em; }
.profile-title { margin-top: 10px; font-size: 13.5px; font-weight: 600; color: var(--accent); }
.profile-affil { margin-top: 5px; font-size: 13px; color: var(--muted); line-height: 1.55; }
.profile-loc { margin-top: 8px; font-size: 12.5px; color: var(--muted); display: inline-flex; align-items: center; gap: 5px; }
.profile-loc svg { flex: none; }

.keyword-chips { display: flex; flex-wrap: wrap; justify-content: center; gap: 6px; margin-top: 16px; }
.keyword-chips span {
  font-size: 11.5px; font-weight: 500; letter-spacing: 0.02em;
  padding: 4px 10px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent);
  border: 1px solid color-mix(in srgb, var(--accent) 22%, transparent);
}

.profile-links { display: flex; justify-content: center; gap: 9px; margin-top: 20px; padding-top: 18px; border-top: 1px solid var(--line); }
.profile-links a {
  display: grid; place-items: center; width: 37px; height: 37px;
  border: 1px solid var(--line); border-radius: 10px; color: var(--ink-soft);
  background: var(--surface); transition: all 0.22s;
}
.profile-links a:hover { color: #fff; background: var(--accent); border-color: var(--accent); transform: translateY(-2px); box-shadow: var(--shadow-md); }
html[data-theme="dark"] .profile-links a:hover { color: #10141a; }

/* ---------- 主内容区 ---------- */
.content { min-width: 0; }
.section { margin-bottom: 64px; }
.section-head { margin-bottom: 24px; }
.kicker {
  display: inline-block; font-family: var(--mono); font-size: 11px; font-weight: 500;
  letter-spacing: 0.22em; text-transform: uppercase; color: var(--accent); margin-bottom: 6px;
}
.section-head h2 {
  font-family: var(--serif); font-size: 30px; font-weight: 700; letter-spacing: -0.01em;
  position: relative; padding-bottom: 12px;
}
.section-head h2::after {
  content: ""; position: absolute; left: 0; bottom: 0;
  width: 46px; height: 3px; border-radius: 3px;
  background: linear-gradient(90deg, var(--accent), var(--gold));
}

/* About */
.about-body p { margin-bottom: 14px; color: var(--ink-soft); max-width: 72ch; }
.about-body p:last-child { margin-bottom: 0; }
.research-figure {
  margin: 22px 0 4px; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; background: var(--surface); box-shadow: var(--shadow-sm);
}
.research-figure img { display: block; width: 100%; transition: transform 0.4s ease; }
.research-figure a:hover img { transform: scale(1.015); }
.research-figure figcaption {
  padding: 11px 16px; font-size: 12.6px; color: var(--muted); line-height: 1.55;
  border-top: 1px solid var(--line); font-style: italic;
}
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin-top: 26px; }
.stat-card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px 16px 15px; box-shadow: var(--shadow-sm); text-align: center;
  transition: transform 0.25s, box-shadow 0.25s, background 0.35s, border-color 0.35s;
}
.stat-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.stat-value { font-family: var(--serif); font-size: 27px; font-weight: 700; color: var(--accent); line-height: 1.15; }
.stat-label { margin-top: 5px; font-size: 11.8px; font-weight: 500; color: var(--muted); line-height: 1.4; }

/* News */
.news-list { list-style: none; position: relative; }
.news-list::before {
  content: ""; position: absolute; left: 68px; top: 8px; bottom: 8px; width: 1px; background: var(--line);
}
.news-item { display: grid; grid-template-columns: 52px 1fr; gap: 32px; padding: 11px 0; position: relative; }
.news-item::before {
  content: ""; position: absolute; left: 64.5px; top: 20px; width: 8px; height: 8px;
  border-radius: 50%; background: var(--bg); border: 2px solid var(--accent);
}
.news-date { font-family: var(--mono); font-size: 12px; font-weight: 500; color: var(--accent); text-align: right; padding-top: 2.5px; letter-spacing: 0.02em; }
.news-text { color: var(--ink-soft); font-size: 14.8px; }

/* Publications */
.pub-filters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 22px; }
.pub-filter {
  padding: 6px 15px; font-size: 12.8px; font-weight: 500; border-radius: 999px;
  border: 1px solid var(--line); background: var(--surface); color: var(--muted);
  cursor: pointer; transition: all 0.2s; font-family: var(--sans);
}
.pub-filter:hover { border-color: var(--accent); color: var(--accent); }
.pub-filter.active { background: var(--accent); border-color: var(--accent); color: #fff; }
html[data-theme="dark"] .pub-filter.active { color: #10141a; }

.pub-list { list-style: none; counter-reset: pub; }
.pub-item {
  counter-increment: pub; position: relative; padding: 17px 18px 17px 52px;
  border-radius: var(--radius); transition: background 0.25s;
}
.pub-item:hover { background: var(--surface); box-shadow: var(--shadow-sm); }
.pub-item::before {
  content: counter(pub, decimal-leading-zero);
  position: absolute; left: 14px; top: 21px;
  font-family: var(--mono); font-size: 12.5px; font-weight: 500; color: var(--accent); opacity: 0.85;
}
.pub-authors { font-size: 13.6px; color: var(--muted); line-height: 1.6; }
.pub-authors strong { color: var(--ink); font-weight: 600; }
.pub-title { font-family: var(--serif); font-size: 16.6px; font-weight: 600; line-height: 1.5; margin: 3px 0; }
.pub-venue { font-family: var(--serif); font-style: italic; font-size: 14.2px; color: var(--accent); }
.pub-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 7px; margin-top: 9px; }
.pub-tag {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.08em; text-transform: uppercase;
  padding: 3px 9px; border-radius: 6px; background: var(--surface-2); color: var(--muted);
  border: 1px solid var(--line);
}
.pub-link {
  display: inline-flex; align-items: center; gap: 4px;
  font-size: 12px; font-weight: 600; padding: 3.5px 11px; border-radius: 7px;
  border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
  color: var(--accent); transition: all 0.2s;
}
.pub-link:hover { background: var(--accent); color: #fff; border-color: var(--accent); }
html[data-theme="dark"] .pub-link:hover { color: #10141a; }
.pub-note { margin-top: 14px; font-size: 12.8px; color: var(--muted); font-style: italic; }

/* 带配图的论文条目：左文右图 */
.pub-item.with-image { display: flex; gap: 22px; align-items: flex-start; }
.pub-item.with-image .pub-body { flex: 1; min-width: 0; }
.pub-thumb {
  flex: none; width: 208px; margin-top: 2px;
  border: 1px solid var(--line); border-radius: 10px; overflow: hidden;
  box-shadow: var(--shadow-sm); transition: transform 0.25s, box-shadow 0.25s;
  background: var(--surface);
}
/* 缩略图限高：超长的图（如长条海报图）只显示顶部区域，点击仍打开完整原图
   想调整缩略图显示高度，只改下面 max-height 的数值即可（单位 px，越小越扁） */
.pub-thumb img { display: block; width: 100%; max-height: 190px; object-fit: cover; object-position: top center; }
.pub-thumb:hover { transform: translateY(-2px) scale(1.02); box-shadow: var(--shadow-md); }
@media (max-width: 720px) {
  .pub-item.with-image { flex-direction: column-reverse; }
  .pub-thumb { width: 100%; max-width: 340px; }
}

.manuscripts { margin-top: 26px; border: 1px dashed var(--line); border-radius: var(--radius); padding: 16px 20px; background: var(--surface); }
.manuscripts summary {
  cursor: pointer; font-family: var(--serif); font-size: 16.5px; font-weight: 600;
  color: var(--ink); list-style: none; display: flex; align-items: center; gap: 8px;
}
.manuscripts summary::before { content: "+"; font-family: var(--mono); color: var(--accent); font-size: 17px; transition: transform 0.25s; }
.manuscripts[open] summary::before { transform: rotate(45deg); }
.manuscripts summary:hover { color: var(--accent); }
#manuCount { font-family: var(--mono); font-size: 11.5px; color: var(--muted); font-weight: 400; }
.manu-list { margin-top: 13px; padding-left: 18px; }
.manu-list li { font-size: 13.8px; color: var(--muted); margin-bottom: 8px; line-height: 1.6; }
.manu-list li::marker { color: var(--accent); }

/* Research / Teaching 卡片 */
.card-list { display: flex; flex-direction: column; gap: 15px; }
.exp-card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 21px 24px; box-shadow: var(--shadow-sm);
  transition: transform 0.25s, box-shadow 0.25s, background 0.35s, border-color 0.35s;
  border-left: 3px solid var(--accent);
}
.exp-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.exp-head { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; flex-wrap: wrap; }
.exp-role { font-family: var(--serif); font-size: 17px; font-weight: 600; line-height: 1.45; }
.exp-period { font-family: var(--mono); font-size: 12px; color: var(--accent); white-space: nowrap; }
.exp-org { font-size: 13.4px; color: var(--muted); margin-top: 3px; }
.exp-project { font-size: 13.8px; font-weight: 600; color: var(--ink-soft); margin-top: 8px; }
.exp-desc { font-size: 14px; color: var(--muted); margin-top: 6px; line-height: 1.68; }
.exp-note {
  font-size: 13px; color: var(--ink-soft); margin-top: 9px; line-height: 1.6;
  padding: 8px 12px; border-radius: 8px; background: var(--accent-soft);
  border-left: 3px solid var(--accent);
}
/* 带配图的研究卡片 */
.exp-card.with-image { display: flex; gap: 22px; align-items: flex-start; }
.exp-card.with-image .exp-body { flex: 1; min-width: 0; }
.exp-thumbs { flex: none; width: 208px; display: flex; flex-direction: column; gap: 10px; }
.exp-thumbs .pub-thumb { width: 100%; margin-top: 0; }
@media (max-width: 720px) {
  .exp-card.with-image { flex-direction: column-reverse; }
  .exp-thumbs { width: 100%; max-width: 340px; }
}

/* ---------- 侧栏访客地图 ---------- */
:root { --map-land: #e4e9ed; }
html[data-theme="dark"] { --map-land: #2a323d; }
.visitor-map { margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--line); }
.visitor-map-canvas { display: block; width: 100%; }
.visitor-map-caption { margin: 6px 0 0; font-size: 11.5px; color: var(--muted); line-height: 1.35; text-align: center; }
.visitor-map-tip {
  position: absolute; pointer-events: none; z-index: 1000;
  background: rgba(30, 36, 44, 0.94); color: #fff;
  padding: 5px 9px; border-radius: 6px; font-size: 11.5px; white-space: nowrap;
  opacity: 0; transition: opacity 0.12s;
}
.visitor-map-tip-sub { margin-top: 2px; font-size: 10.5px; opacity: 0.75; }
/* 手机端侧栏堆叠在内容上方，地图意义不大且占位，隐藏 */
@media (max-width: 1020px) {
  .visitor-map { display: none !important; }
}

/* Awards */
.awards-list { list-style: none; display: grid; grid-template-columns: 1fr 1fr; gap: 10px 26px; }
.award-item {
  display: grid; grid-template-columns: 62px 1fr; gap: 13px; align-items: baseline;
  padding: 10px 12px; border-radius: 10px; transition: background 0.2s;
}
.award-item:hover { background: var(--surface); box-shadow: var(--shadow-sm); }
.award-year { font-family: var(--mono); font-size: 12.5px; font-weight: 500; color: var(--accent); text-align: right; }
.award-text { font-size: 13.9px; color: var(--ink-soft); line-height: 1.55; }

/* Talks */
.talks-list { list-style: none; }
.talk-item {
  display: grid; grid-template-columns: 62px 1fr; gap: 16px; padding: 13px 12px;
  border-radius: 10px; transition: background 0.2s; align-items: baseline;
}
.talk-item:hover { background: var(--surface); box-shadow: var(--shadow-sm); }
.talk-date { font-family: var(--mono); font-size: 12.5px; font-weight: 500; color: var(--accent); text-align: right; }
.talk-title { font-family: var(--serif); font-size: 15.6px; font-weight: 600; line-height: 1.5; }
.talk-title::before { content: "“"; color: var(--accent); }
.talk-title::after { content: "”"; color: var(--accent); }
.talk-venue { font-size: 13.2px; color: var(--muted); margin-top: 2px; }

/* Education 时间线 */
.edu-list { position: relative; padding-left: 24px; }
.edu-list::before { content: ""; position: absolute; left: 5px; top: 10px; bottom: 10px; width: 1px; background: var(--line); }
.edu-item { position: relative; padding: 0 0 26px 18px; }
.edu-item:last-child { padding-bottom: 0; }
.edu-item::before {
  content: ""; position: absolute; left: -24.5px; top: 7px; width: 10px; height: 10px;
  border-radius: 50%; background: var(--bg); border: 2.5px solid var(--accent);
}
.edu-degree { font-family: var(--serif); font-size: 16.8px; font-weight: 600; line-height: 1.45; }
.edu-school { font-size: 14px; color: var(--accent); font-weight: 500; margin-top: 2px; }
.edu-meta { display: flex; flex-wrap: wrap; gap: 6px 14px; margin-top: 4px; }
.edu-period { font-family: var(--mono); font-size: 12px; color: var(--muted); }
.edu-detail { font-size: 12.8px; color: var(--muted); font-weight: 500; }
.edu-thesis { font-size: 13.6px; color: var(--muted); margin-top: 6px; line-height: 1.65; max-width: 72ch; }

/* Service */
.service-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; }
.service-card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 19px 22px; box-shadow: var(--shadow-sm);
  transition: background 0.35s, border-color 0.35s, transform 0.25s, box-shadow 0.25s;
}
.service-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.service-group { font-family: var(--serif); font-size: 15.8px; font-weight: 600; margin-bottom: 9px; color: var(--ink); }
.service-group::before { content: "—"; color: var(--accent); margin-right: 7px; }
.service-card ul { list-style: none; }
.service-card li { font-size: 13.6px; color: var(--muted); padding: 3.5px 0 3.5px 15px; position: relative; line-height: 1.55; }
.service-card li::before { content: ""; position: absolute; left: 0; top: 11px; width: 5px; height: 5px; border-radius: 50%; background: var(--accent); opacity: 0.6; }

.certs { margin-top: 26px; }
.certs h3 { font-family: var(--serif); font-size: 17.5px; font-weight: 600; margin-bottom: 12px; }
.cert-list { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; }
.cert-list li {
  font-size: 12.6px; color: var(--ink-soft); background: var(--surface);
  border: 1px solid var(--line); border-radius: 999px; padding: 5.5px 14px;
  transition: all 0.2s;
}
.cert-list li:hover { border-color: var(--accent); color: var(--accent); }

/* Footer */
.footer { margin-top: 70px; padding-top: 26px; border-top: 1px solid var(--line); text-align: center; }
.footer p { font-size: 13px; color: var(--muted); line-height: 1.7; }
.footer .copy { margin-top: 8px; font-size: 12.3px; opacity: 0.75; }

/* ---------- CV 页面（cv.html） ---------- */
.cv-main {
  max-width: 1180px; margin: 0 auto;
  padding: calc(var(--topnav-h) + 28px) 28px 40px;
  display: flex; flex-direction: column; min-height: 100vh;
}
.cv-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 18px; flex-wrap: wrap; }
.cv-title { font-family: var(--serif); font-size: 28px; font-weight: 700; letter-spacing: -0.01em; }
.cv-download {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 9px 20px; border-radius: 10px; font-size: 13.5px; font-weight: 600;
  background: var(--accent); color: #fff !important; border: 1px solid var(--accent);
  transition: all 0.22s;
}
.cv-download:hover { background: var(--accent-hover); transform: translateY(-1px); box-shadow: var(--shadow-md); }
html[data-theme="dark"] .cv-download { color: #10141a !important; }
.cv-viewer {
  flex: 1; position: relative; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; background: var(--surface); box-shadow: var(--shadow-sm); min-height: 70vh;
}
.cv-viewer embed { width: 100%; height: 100%; min-height: 70vh; border: none; display: block; }
.cv-fallback {
  position: absolute; inset: 0; display: none; flex-direction: column;
  align-items: center; justify-content: center; gap: 12px; color: var(--muted); font-size: 14px;
}
/* 导航里的 CV 链接（与其他锚点链接区分，当前页高亮） */
.nav-links a.nav-cv { font-weight: 600; }
.nav-links a.nav-cv.active { color: var(--accent); }
.nav-links a.nav-cv.active::after { content: ""; position: absolute; left: 11px; right: 11px; bottom: 2px; height: 2px; border-radius: 2px; background: var(--accent); }

/* 返回顶部 */
.back-to-top {
  position: fixed; right: 26px; bottom: 26px; width: 42px; height: 42px;
  display: grid; place-items: center; border-radius: 12px;
  background: var(--accent); color: #fff; border: none; cursor: pointer;
  opacity: 0; visibility: hidden; transform: translateY(12px);
  transition: all 0.3s; box-shadow: var(--shadow-md); z-index: 900;
}
.back-to-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { background: var(--accent-hover); transform: translateY(-3px); }
html[data-theme="dark"] .back-to-top { color: #10141a; }

/* 滚动渐入动画 */
.reveal { opacity: 0; transform: translateY(16px); }
.reveal.visible { opacity: 1; transform: translateY(0); transition: opacity 0.6s ease, transform 0.6s ease; }

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

/* ---------- 响应式 ---------- */
@media (max-width: 1020px) {
  .layout { grid-template-columns: 1fr; gap: 40px; }
  .sidebar { position: static; }
  .profile-card { max-width: 430px; margin: 0 auto; }
}
@media (max-width: 860px) {
  .menu-toggle { display: flex; }
  .nav-links {
    position: fixed; top: var(--topnav-h); left: 0; right: 0;
    flex-direction: column; gap: 2px; padding: 14px 20px 18px;
    background: var(--bg); border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-md);
    opacity: 0; visibility: hidden; transform: translateY(-8px);
    transition: all 0.28s ease;
  }
  .nav-links.open { opacity: 1; visibility: visible; transform: translateY(0); }
  .nav-links a { padding: 10px 12px; font-size: 14.5px; }
  .nav-links a.active::after { display: none; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .awards-list, .service-grid { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  body { font-size: 15px; }
  .layout { padding: calc(var(--topnav-h) + 26px) 18px 50px; }
  .section-head h2 { font-size: 25px; }
  .news-item { grid-template-columns: 46px 1fr; gap: 22px; }
  .news-list::before { left: 60px; }
  .news-item::before { left: 56.5px; }
  .exp-head { flex-direction: column; gap: 2px; }
  .pub-item { padding-left: 44px; }
}