:root {
  --paper: #efe8dc;
  --ink: #1a1713;
  --mute: #6b6458;
  --line: rgba(26, 23, 19, 0.12);
  --patina: #3d6b5c;
  --danger: #96401f;
  --pad: 8vw;
}

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

html { scroll-behavior: smooth; }

body {
  min-height: 100vh;
  background: var(--paper);
  color: var(--ink);
  font-family: "Iowan Old Style", "Palatino Linotype", "Songti SC", "STSong", Georgia, serif;
  line-height: 1.6;
  overflow-x: hidden;
}

#field {
  position: fixed;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.top, main, footer, .flashes {
  position: relative;
  z-index: 1;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* ===== 顶栏 ===== */
.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px var(--pad);
  border-bottom: 1px solid var(--line);
}

.mark {
  display: flex;
  flex-direction: column;
  gap: 3px;
  text-decoration: none;
  color: var(--ink);
  font-size: 16px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  font-weight: 600;
}

.mark em {
  font-style: normal;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--patina);
  text-transform: none;
}

nav { display: flex; gap: 26px; }

nav a {
  color: var(--mute);
  text-decoration: none;
  font-size: 14px;
  letter-spacing: 0.08em;
}

nav a:hover { color: var(--patina); }

/* ===== 提示条 ===== */
.flashes { padding: 16px var(--pad) 0; }

.flash {
  padding: 10px 16px;
  border-left: 2px solid var(--patina);
  background: rgba(61, 107, 92, 0.08);
  font-size: 15px;
  max-width: 44em;
}

.flash + .flash { margin-top: 8px; }

.flash-error {
  border-left-color: var(--danger);
  background: rgba(150, 64, 31, 0.08);
}

/* ===== 首屏 ===== */
.hero {
  min-height: calc(100vh - 130px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 8vh var(--pad) 12vh;
  max-width: 1160px;
}

.kicker {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--patina);
  margin-bottom: 26px;
}

h1 {
  font-size: clamp(46px, 8.5vw, 108px);
  font-weight: 500;
  line-height: 0.98;
  letter-spacing: -0.03em;
}

.lede {
  max-width: 34em;
  margin-top: 30px;
  font-size: clamp(16px, 1.8vw, 20px);
  color: var(--mute);
}

.cta {
  align-self: flex-start;
  margin-top: 36px;
  padding: 12px 26px;
  border: 1px solid var(--patina);
  border-radius: 2px;
  color: var(--patina);
  text-decoration: none;
  font-size: 14px;
  letter-spacing: 0.1em;
  transition: background 0.2s, color 0.2s;
}

.cta:hover {
  background: var(--patina);
  color: var(--paper);
}

/* ===== 通用分节 ===== */
.section {
  border-top: 1px solid var(--line);
  padding: 72px 0 0;
}

.section:first-child { border-top: none; }

.section-head {
  padding: 0 var(--pad) 40px;
  max-width: 1160px;
}

.section-head h2 {
  font-size: 13px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--patina);
  font-weight: 600;
}

.section-head p {
  margin-top: 14px;
  max-width: 36em;
  color: var(--mute);
  font-size: 16px;
}

.empty, .more {
  padding: 0 var(--pad) 76px;
  color: var(--mute);
  font-size: 16px;
}

.more a { color: var(--patina); text-decoration: none; }
.more a:hover { text-decoration: underline; }

/* ===== 研究方向 ===== */
.notes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
}

.notes article {
  padding: 44px var(--pad) 56px;
  border-right: 1px solid var(--line);
}

.notes article:last-child { border-right: none; }

.notes span {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 12px;
  color: var(--patina);
  letter-spacing: 0.16em;
}

.notes h3 {
  margin: 14px 0 12px;
  font-size: 26px;
  font-weight: 500;
}

.notes p { color: var(--mute); font-size: 16px; }

/* ===== 时间线 ===== */
.timeline {
  list-style: none;
  padding: 0 var(--pad) 76px;
  max-width: 1160px;
}

.timeline li {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 28px;
  padding: 26px 0;
  border-top: 1px solid var(--line);
}

.timeline time {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 13px;
  color: var(--patina);
  letter-spacing: 0.06em;
  padding-top: 4px;
}

.timeline h3 {
  font-size: 20px;
  font-weight: 500;
  margin-bottom: 8px;
}

.timeline h3 a { color: var(--ink); text-decoration: none; }
.timeline h3 a:hover { color: var(--patina); }

.timeline p { color: var(--mute); font-size: 16px; max-width: 40em; }

.tag {
  display: inline-block;
  margin-top: 10px;
  padding: 2px 10px;
  border: 1px solid var(--line);
  border-radius: 2px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--patina);
}

/* ===== 检索 ===== */
.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  padding: 0 var(--pad) 48px;
}

.filters input, .filters select, .subscribe input {
  padding: 11px 14px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.4);
  color: var(--ink);
  font-family: inherit;
  font-size: 15px;
}

.filters input { min-width: 240px; }

.filters button, .subscribe button {
  padding: 11px 24px;
  border: 1px solid var(--patina);
  border-radius: 2px;
  background: transparent;
  color: var(--patina);
  font-family: inherit;
  font-size: 15px;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

.filters button:hover, .subscribe button:hover {
  background: var(--patina);
  color: var(--paper);
}

/* ===== 正文 ===== */
.prose {
  padding: 0 var(--pad) 80px;
  max-width: 42em;
}

.prose p { color: var(--mute); font-size: 17px; }
.prose p + p { margin-top: 18px; }

.article-head { padding: 0 var(--pad) 44px; max-width: 42em; }
.article-head h1 { font-size: clamp(34px, 5vw, 60px); line-height: 1.06; }

.article-body { color: var(--mute); }
.article-body h2, .article-body h3 { color: var(--ink); font-weight: 500; margin: 32px 0 12px; }
.article-body h2 { font-size: 26px; }
.article-body h3 { font-size: 21px; }
.article-body ul, .article-body ol { margin: 14px 0 14px 22px; font-size: 17px; }
.article-body li + li { margin-top: 6px; }
.article-body a { color: var(--patina); }

.article-body pre {
  margin: 20px 0;
  padding: 16px 18px;
  overflow-x: auto;
  background: rgba(26, 23, 19, 0.06);
  border-radius: 3px;
}

.article-body code {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 14px;
}

.article-body blockquote {
  margin: 20px 0;
  padding-left: 18px;
  border-left: 2px solid var(--patina);
}

.article-body table { width: 100%; border-collapse: collapse; margin: 20px 0; font-size: 15px; }
.article-body th, .article-body td { padding: 10px 12px; border-bottom: 1px solid var(--line); text-align: left; }

/* ===== 联系与订阅 ===== */
.contact { padding-bottom: 88px; }

.contact-body {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 24px;
  padding: 0 var(--pad);
}

.contact-body .cta {
  margin-top: 0;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
}

.subscribe { display: flex; gap: 10px; flex-wrap: wrap; }
.subscribe input[type="email"] { min-width: 240px; }
.honeypot { position: absolute; left: -9999px; opacity: 0; }

footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 24px var(--pad) 36px;
  border-top: 1px solid var(--line);
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mute);
}

footer a { color: var(--patina); text-decoration: none; }

@media (max-width: 860px) {
  :root { --pad: 20px; }
  .top { padding: 16px var(--pad); }
  nav { gap: 18px; }
  nav a { font-size: 13px; }
  .hero { min-height: auto; padding: 12vh var(--pad) 14vh; }
  .notes { grid-template-columns: 1fr; }
  .notes article {
    border-right: none;
    border-bottom: 1px solid var(--line);
    padding: 32px var(--pad);
  }
  .timeline li { grid-template-columns: 1fr; gap: 10px; }
  .contact-body { align-items: stretch; flex-direction: column; }
  footer { flex-direction: column; gap: 8px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}