/* =====================================================================
 *  个人学术主页样式
 *  设计：简洁、低饱和度色块、浅/深色自动切换
 * ===================================================================== */

/* ---------- 主题变量 ---------- */
:root {
  /* 低饱和度调色板 —— 浅色 */
  --bg:          #f7f6f3;   /* 米白背景 */
  --bg-alt:      #efeee9;   /* 交替区块 */
  --surface:     #ffffff;   /* 卡片 */
  --surface-2:   #f2f1ec;
  --text:        #2c2c2e;   /* 主文字 */
  --text-soft:   #6b6b70;   /* 次要文字 */
  --text-faint:  #9a9a9f;
  --border:      #e4e2db;
  --shadow:      0 1px 2px rgba(40,40,45,.04), 0 8px 24px rgba(40,40,45,.06);

  /* 低饱和度强调色块（蓝色主调） */
  --accent:      #5b7ba6;   /* 低饱和蓝 */
  --accent-soft: #dde6f1;
  --c-sage:      #7d9bc1;   /* 雾蓝 */
  --c-clay:      #c8a99a;   /* 陶土 */
  --c-mist:      #9fb0bd;   /* 灰蓝 */
  --c-sand:      #d4c6a8;   /* 沙 */
  --c-lilac:     #a7afc9;   /* 蓝紫 */

  --radius:      16px;
  --radius-sm:   10px;
  --maxw:        1040px;
  --font-sans:   "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-serif:  "Lora", Georgia, serif;
  --ease:        cubic-bezier(.22,.61,.36,1);
}

/* ---------- 深色（自动 + 手动） ---------- */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:          #1a1a1c;
    --bg-alt:      #202023;
    --surface:     #242427;
    --surface-2:   #2c2c30;
    --text:        #e9e8e4;
    --text-soft:   #a8a8ad;
    --text-faint:  #74747a;
    --border:      #33333a;
    --shadow:      0 1px 2px rgba(0,0,0,.3), 0 8px 28px rgba(0,0,0,.35);
    --accent:      #7fa0cc;
    --accent-soft: #28344a;
    --c-sage:      #5e7ba3;
    --c-clay:      #8f7167;
    --c-mist:      #6c7d8a;
    --c-sand:      #8a7e60;
    --c-lilac:     #6f7596;
  }
}
:root[data-theme="dark"] {
  --bg:          #1a1a1c;
  --bg-alt:      #202023;
  --surface:     #242427;
  --surface-2:   #2c2c30;
  --text:        #e9e8e4;
  --text-soft:   #a8a8ad;
  --text-faint:  #74747a;
  --border:      #33333a;
  --shadow:      0 1px 2px rgba(0,0,0,.3), 0 8px 28px rgba(0,0,0,.35);
  --accent:      #7fa0cc;
  --accent-soft: #28344a;
  --c-sage:      #5e7ba3;
  --c-clay:      #8f7167;
  --c-mist:      #6c7d8a;
  --c-sand:      #8a7e60;
  --c-lilac:     #6f7596;
}

/* ---------- 基础 ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  transition: background .4s var(--ease), color .4s var(--ease);
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
::selection { background: var(--accent-soft); }

/* ---------- 导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  background: color-mix(in srgb, var(--bg) 80%, transparent);
  border-bottom: 1px solid transparent;
  transition: border-color .3s var(--ease), background .4s var(--ease);
}
.nav.scrolled { border-bottom-color: var(--border); }
.nav__inner {
  max-width: var(--maxw); margin: 0 auto;
  display: flex; align-items: center; gap: 18px;
  padding: 14px 24px;
}
.nav__brand {
  font-weight: 700; font-size: 17px; letter-spacing: .2px;
  margin-right: auto;
}
.nav__links { display: flex; gap: 4px; }
.nav__link {
  font-size: 14px; color: var(--text-soft);
  padding: 7px 12px; border-radius: 8px;
  transition: color .2s, background .2s;
}
.nav__link:hover { color: var(--text); background: var(--surface-2); }
.nav__link.active { color: var(--accent); font-weight: 600; }

.theme-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; border-radius: 10px;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text-soft); cursor: pointer;
  transition: transform .25s var(--ease), color .2s, border-color .2s;
}
.theme-toggle:hover { color: var(--accent); border-color: var(--accent); transform: translateY(-1px); }
.theme-toggle svg { fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.icon-moon { display: none; }
:root[data-theme="dark"] .icon-sun,
:root[data-theme="light"] .icon-moon { display: none; }
:root[data-theme="dark"] .icon-moon { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .icon-sun { display: none; }
  :root:not([data-theme="light"]) .icon-moon { display: block; }
}

.nav__burger { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 8px; }
.nav__burger span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; transition: .3s var(--ease); }

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden;
  padding: 96px 24px 80px;
}
.hero__inner {
  position: relative; z-index: 2;
  max-width: var(--maxw); margin: 0 auto;
  display: grid; grid-template-columns: 1fr auto; gap: 48px; align-items: center;
}
.hero__text { max-width: 620px; }
.hero__greet { color: var(--accent); font-weight: 600; font-size: 15px; letter-spacing: .5px; }
.hero__name {
  font-family: var(--font-serif);
  font-size: clamp(34px, 6vw, 56px); line-height: 1.1; margin: 10px 0 6px;
  letter-spacing: -.5px;
}
.hero__name-en { font-size: 18px; color: var(--text-faint); font-weight: 500; }
.hero__role { font-size: clamp(17px, 2.4vw, 21px); color: var(--text); margin-top: 18px; font-weight: 500; }
.hero__affil { color: var(--text-soft); margin-top: 4px; }
.hero__short { color: var(--text-soft); margin-top: 18px; font-size: 16px; max-width: 540px; }
.hero__meta { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 18px; color: var(--text-faint); font-size: 14px; }
.hero__meta span { display: inline-flex; align-items: center; gap: 6px; }

.hero__links { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 14px; font-weight: 500;
  padding: 9px 16px; border-radius: 10px;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text); cursor: pointer;
  transition: transform .2s var(--ease), border-color .2s, color .2s, background .2s;
}
.btn:hover { transform: translateY(-2px); border-color: var(--accent); color: var(--accent); }
.btn--primary { background: var(--accent); color: #fff; border-color: var(--accent); }
:root[data-theme="dark"] .btn--primary { color: #16160f; }
.btn--primary:hover { color: #fff; filter: brightness(1.05); }
:root[data-theme="dark"] .btn--primary:hover { color: #16160f; }

/* 头像 */
.hero__avatar {
  width: 200px; height: 200px; border-radius: 24px;
  background: var(--surface); border: 1px solid var(--border);
  box-shadow: var(--shadow); overflow: hidden;
  display: flex; align-items: center; justify-content: center;
}
.hero__avatar img { width: 100%; height: 100%; object-fit: cover; }

/* 背景色块 */
.hero__blob { position: absolute; border-radius: 50%; filter: blur(60px); opacity: .5; z-index: 1; pointer-events: none; }
.hero__blob--1 { width: 360px; height: 360px; background: var(--c-sage); top: -120px; right: -60px; }
.hero__blob--2 { width: 280px; height: 280px; background: var(--c-mist); bottom: -120px; left: -40px; opacity: .42; }
.hero__blob--3 { width: 220px; height: 220px; background: var(--c-clay); top: 40%; left: 45%; opacity: .3; }

/* ---------- 区块通用 ---------- */
.section { max-width: var(--maxw); margin: 0 auto; padding: 72px 24px; }
.section--alt { max-width: 100%; background: var(--bg-alt); transition: background .4s var(--ease); }
.section--alt > * { max-width: var(--maxw); margin-left: auto; margin-right: auto; }
.section__head { margin-bottom: 36px; }
.section__eyebrow {
  display: inline-block; font-size: 13px; font-weight: 600; letter-spacing: 1.5px;
  text-transform: uppercase; color: var(--accent);
  padding: 4px 10px; border-radius: 6px; background: var(--accent-soft); margin-bottom: 12px;
}
.section__title { font-family: var(--font-serif); font-size: clamp(26px, 4vw, 34px); letter-spacing: -.3px; }

/* ---------- 关于 ---------- */
.about { display: grid; grid-template-columns: 1.7fr 1fr; gap: 40px; align-items: start; }
.about__bio p { color: var(--text-soft); margin-bottom: 16px; font-size: 16px; }
.about__bio p:first-child { color: var(--text); font-size: 17px; }
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow);
}
.card__title { font-size: 16px; margin-bottom: 16px; font-weight: 600; }
.tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  font-size: 13px; padding: 6px 12px; border-radius: 100px;
  background: var(--surface-2); color: var(--text-soft); border: 1px solid var(--border);
  transition: .2s var(--ease);
}
.tag:hover { color: var(--text); border-color: var(--accent); transform: translateY(-1px); }
/* 不同色块的标签点缀 */
.tag:nth-child(5n+1){ border-left: 3px solid var(--c-sage); }
.tag:nth-child(5n+2){ border-left: 3px solid var(--c-mist); }
.tag:nth-child(5n+3){ border-left: 3px solid var(--c-clay); }
.tag:nth-child(5n+4){ border-left: 3px solid var(--c-sand); }
.tag:nth-child(5n+5){ border-left: 3px solid var(--c-lilac); }

/* ---------- 最新消息 ---------- */
.news { list-style: none; display: flex; flex-direction: column; gap: 2px; }
.news__item {
  display: grid; grid-template-columns: 92px 1fr; gap: 20px; align-items: baseline;
  padding: 16px 18px; border-radius: var(--radius-sm);
  transition: background .25s var(--ease);
}
.news__item:hover { background: var(--surface); }
.news__date {
  font-size: 13px; font-weight: 600; color: var(--accent);
  font-variant-numeric: tabular-nums; white-space: nowrap;
}
.news__content { color: var(--text-soft); font-size: 15.5px; }
.news__content strong { color: var(--text); font-weight: 600; }

/* ---------- 论文 ---------- */
.pub-filters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 24px; }
.filter-btn {
  font-size: 13.5px; padding: 7px 15px; border-radius: 100px;
  border: 1px solid var(--border); background: var(--surface); color: var(--text-soft);
  cursor: pointer; transition: .2s var(--ease);
}
.filter-btn:hover { color: var(--text); border-color: var(--accent); }
.filter-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }
:root[data-theme="dark"] .filter-btn.active { color: #16160f; }

.pubs { list-style: none; display: flex; flex-direction: column; gap: 14px; counter-reset: pub; }
.pub {
  position: relative; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px 22px 20px 24px; box-shadow: var(--shadow);
  transition: transform .25s var(--ease), border-color .25s, box-shadow .25s;
  overflow: hidden;
}
.pub::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 4px;
  background: var(--c-mist); transition: width .25s var(--ease);
}
.pub.is-highlight::before { background: var(--accent); }
.pub:hover { transform: translateY(-3px); border-color: var(--accent); }
.pub:hover::before { width: 6px; }
.pub__meta { display: flex; align-items: center; gap: 10px; margin-bottom: 8px; }
.pub__year { font-size: 13px; font-weight: 600; color: var(--text-faint); font-variant-numeric: tabular-nums; }
.pub__type {
  font-size: 12px; padding: 2px 9px; border-radius: 6px;
  background: var(--accent-soft); color: var(--accent); font-weight: 600;
}
.pub__badge { font-size: 12px; color: var(--c-clay); font-weight: 600; margin-left: auto; }
.pub__title { font-size: 16.5px; font-weight: 600; line-height: 1.45; margin-bottom: 6px; }
.pub__authors { font-size: 14px; color: var(--text-soft); margin-bottom: 4px; }
.pub__authors b { color: var(--text); }
.pub__venue { font-size: 14px; color: var(--text-faint); font-style: italic; }
.pub__links { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.pub__link {
  font-size: 12.5px; font-weight: 500; padding: 4px 11px; border-radius: 7px;
  border: 1px solid var(--border); color: var(--text-soft); transition: .2s var(--ease);
}
.pub__link:hover { color: var(--accent); border-color: var(--accent); background: var(--accent-soft); }

/* ---------- 经历 / 授课 ---------- */
.cols { display: grid; grid-template-columns: 1.6fr 1fr; gap: 40px; align-items: start; }
.timeline { position: relative; padding-left: 26px; }
.timeline::before {
  content: ""; position: absolute; left: 6px; top: 6px; bottom: 6px; width: 2px; background: var(--border);
}
.timeline__item { position: relative; padding-bottom: 26px; }
.timeline__item:last-child { padding-bottom: 0; }
.timeline__item::before {
  content: ""; position: absolute; left: -26px; top: 6px;
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--surface); border: 2px solid var(--accent);
}
.timeline__period { font-size: 13px; color: var(--accent); font-weight: 600; }
.timeline__title { font-size: 16px; font-weight: 600; margin-top: 2px; }
.timeline__place { font-size: 14px; color: var(--text-soft); }
.teaching { list-style: none; display: flex; flex-direction: column; gap: 14px; }
.teaching li { display: flex; gap: 12px; align-items: baseline; font-size: 15px; }
.teaching__term { font-size: 12.5px; color: var(--text-faint); white-space: nowrap; min-width: 56px; }
.teaching__code { font-weight: 600; color: var(--accent); }

/* ---------- 联系 ---------- */
.contact { text-align: center; max-width: 620px; margin: 0 auto; }
.contact .section__title { margin-top: 8px; }
.contact__text { color: var(--text-soft); margin: 16px auto 28px; font-size: 16px; }
.contact__links { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }

/* ---------- 页脚 ---------- */
.footer {
  text-align: center; padding: 40px 24px 56px;
  color: var(--text-faint); font-size: 13.5px;
  border-top: 1px solid var(--border); background: var(--bg-alt);
  transition: background .4s var(--ease);
}
.footer__note { margin-top: 6px; font-size: 12.5px; }

/* ---------- 回到顶部 ---------- */
.to-top {
  position: fixed; right: 22px; bottom: 22px; z-index: 40;
  width: 42px; height: 42px; border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  background: var(--accent); color: #fff; font-size: 18px;
  box-shadow: var(--shadow); opacity: 0; transform: translateY(12px) scale(.9);
  pointer-events: none; transition: .3s var(--ease);
}
:root[data-theme="dark"] .to-top { color: #16160f; }
.to-top.show { opacity: 1; transform: translateY(0) scale(1); pointer-events: auto; }

/* ---------- 进场动画 ---------- */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 820px) {
  .about, .cols { grid-template-columns: 1fr; }
  .hero__inner { grid-template-columns: 1fr; }
  .hero__avatar { order: -1; width: 130px; height: 130px; }
}
@media (max-width: 640px) {
  .nav__links {
    position: fixed; inset: 64px 0 auto 0;
    flex-direction: column; gap: 0; padding: 12px 20px 20px;
    background: var(--bg); border-bottom: 1px solid var(--border);
    transform: translateY(-130%); transition: transform .35s var(--ease); box-shadow: var(--shadow);
  }
  .nav__links.open { transform: translateY(0); }
  .nav__link { padding: 12px; border-radius: 8px; }
  .nav__burger { display: flex; }
  .news__item { grid-template-columns: 1fr; gap: 4px; }
  .section { padding: 56px 20px; }
}