/* 学术主页样式 — 克制的排版，重内容不重装饰 */

:root {
  --bg: #fdfdfc;
  --fg: #1c1c1e;
  --muted: #6b6b70;
  --rule: #e4e4e2;
  --accent: #2f5d8a;
  --accent-soft: #eef3f8;
  --tag-bg: #f2f2f0;
  --maxw: 44rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16171a;
    --fg: #e8e8e6;
    --muted: #9a9aa0;
    --rule: #2c2e33;
    --accent: #8ab4dc;
    --accent-soft: #1e2733;
    --tag-bg: #24262b;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  text-rendering: optimizeLegibility;
}

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ---------- 页头 ---------- */
header {
  padding: 4.5rem 0 2rem;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 3rem;
}

h1 {
  font-family: Georgia, "Songti SC", "SimSun", serif;
  font-size: 2.1rem;
  font-weight: 600;
  letter-spacing: .01em;
  margin: 0 0 .35rem;
}

.sub {
  margin: 0 0 1rem;
  color: var(--muted);
  font-size: .95rem;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem 1.1rem;
  font-size: .9rem;
}

nav a { color: var(--accent); text-decoration: none; }
nav a:hover { text-decoration: underline; text-underline-offset: 3px; }

/* ---------- 章节 ---------- */
section { margin-bottom: 3.25rem; }

h2 {
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 1.25rem;
}

p { margin: 0 0 1rem; }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

/* ---------- 条目 ---------- */
.item {
  display: grid;
  grid-template-columns: 6.5rem 1fr;
  gap: 0 1.25rem;
  margin-bottom: 1.5rem;
}

.item .when {
  color: var(--muted);
  font-size: .85rem;
  font-variant-numeric: tabular-nums;
  padding-top: .15rem;
}

.item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 .2rem;
}

.item .meta {
  color: var(--muted);
  font-size: .875rem;
  margin: 0 0 .45rem;
}

.item p { margin: .35rem 0 0; font-size: .9375rem; }

ul.plain { margin: .35rem 0 0; padding-left: 1.1rem; }
ul.plain li { margin-bottom: .3rem; font-size: .9375rem; }

/* ---------- 标签 ---------- */
.tags { display: flex; flex-wrap: wrap; gap: .4rem; margin-top: .6rem; }

.tag {
  background: var(--tag-bg);
  color: var(--muted);
  font-size: .78rem;
  padding: .15rem .5rem;
  border-radius: 3px;
  white-space: nowrap;
}

/* ---------- 页脚 ---------- */
footer {
  border-top: 1px solid var(--rule);
  padding: 1.75rem 0 3rem;
  color: var(--muted);
  font-size: .85rem;
}

footer p { margin: 0 0 .4rem; }

/* ---------- 窄屏 ---------- */
@media (max-width: 34rem) {
  header { padding-top: 3rem; }
  h1 { font-size: 1.75rem; }
  .item { grid-template-columns: 1fr; gap: 0; }
  .item .when { padding-top: 0; margin-bottom: .15rem; }
}