@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:ital,wght@0,400;0,500;1,400&display=swap');

:root {
  --paper: #fdfbf7;
  --paper-2: #f5f5f5;
  --ink: #1a1a1a;
  --ink-2: #4a4640;
  --ink-3: #6d675f;
  --rule: #e0e0e0;
  --rule-2: #cfc9c1;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --serif: "Songti SC", "Source Han Serif SC", "Noto Serif SC", Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 17px/1.75 var(--sans);
  letter-spacing: .012em;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 9;
  pointer-events: none;
  opacity: .34;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)' opacity='0.22'/%3E%3C/svg%3E");
}

a { color: inherit; }
img { display: block; max-width: 100%; height: auto; }
p { margin: 0 0 1em; }
h1, h2, h3 { text-wrap: balance; }

:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
}

/* 页头：细条 + 品牌行 + 可折叠索引 */
.masthead {
  position: sticky;
  top: 0;
  z-index: 5;
  background: rgba(253, 251, 247, .95);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--rule-2);
}

.ticker {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 5px 18px;
  background: var(--paper-2);
  border-bottom: 1px solid var(--rule);
  font: 400 12.5px/1.7 var(--mono);
  letter-spacing: .06em;
  color: var(--ink-2);
}

.ticker-dot { font-size: 8px; color: var(--ink); }

.brandline {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 14px;
  padding: 10px 18px;
  border-bottom: 1px solid var(--rule);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  text-decoration: none;
  font: 500 18px/1.3 var(--mono);
  letter-spacing: .015em;
}

.brand-mark {
  flex: none;
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  border: 1px solid var(--ink);
  border-radius: 3px;
  background: var(--paper-2);
  font-size: 14px;
  line-height: 1;
}

.brand-mark--type { font-family: var(--serif); }

.brand-desc {
  margin: 0;
  font: 400 12.5px/1.6 var(--mono);
  color: var(--ink-3);
  letter-spacing: .02em;
}

.navbar { padding: 6px 18px 10px; }

.nav-details > summary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  cursor: pointer;
  list-style: none;
  font: 400 13px/1.2 var(--mono);
  letter-spacing: .12em;
  color: var(--ink-2);
}

.nav-details > summary::-webkit-details-marker { display: none; }

.nav-details > summary::before {
  content: "▤";
  font-size: 13px;
  color: var(--ink);
}

.nav-details[open] > summary { color: var(--ink); }

.pills {
  display: none;
  flex-wrap: wrap;
  gap: 8px;
  margin: 2px 0 0;
  padding: 0;
  list-style: none;
}

.nav-details[open] > .pills { display: flex; }

.pills a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 15px;
  border: 1px solid var(--rule-2);
  border-radius: 999px;
  background: var(--paper);
  text-decoration: none;
  font: 400 15px/1.2 var(--mono);
  letter-spacing: .02em;
}

.pills a:hover,
.pills a:focus-visible {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

.idx {
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--ink-3);
}

.pills a:hover .idx,
.pills a:focus-visible .idx { color: var(--paper); }

/* 版面骨架：正文 + 右栏 */
.sheet {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 18px 44px;
}

.doc { min-width: 0; }

.doc > article {
  padding-bottom: 2em;
  border-bottom: 1px solid var(--rule);
  scroll-margin-top: 160px;
}

.doc > article:last-child { border-bottom: 0; }

/* 首屏 */
.hero {
  position: relative;
  display: flex;
  flex-direction: column-reverse;
  gap: 20px;
  padding: 24px 0 30px;
}

.hero-copy { flex: 1 1 auto; }

.badge {
  display: inline-block;
  margin: 0 0 14px;
  padding: 5px 13px;
  border: 1px solid var(--ink);
  border-radius: 999px;
  background: var(--paper-2);
  font: 400 12px/1.5 var(--mono);
  letter-spacing: .16em;
}

.hero h1 {
  margin: 0 0 14px;
  font-family: var(--serif);
  font-size: clamp(28px, 5.4vw, 46px);
  line-height: 1.32;
  letter-spacing: .008em;
}

.hero-lead {
  margin: 0;
  max-width: 46em;
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.9;
  color: var(--ink-2);
}

.hero-art { flex: none; }

.hero-art img,
.hero-img {
  width: 100%;
  max-width: 220px;
  border: 1px solid var(--rule-2);
  border-radius: 10px;
  background: var(--paper-2);
}

.hero-mark {
  width: 78px;
  height: 78px;
  display: grid;
  place-items: center;
  border: 1px solid var(--ink);
  border-radius: 10px;
  background: var(--paper-2);
  font-family: var(--serif);
  font-size: 32px;
  line-height: 1;
}

/* 正文排版 */
.doc h2 {
  margin: 2.2em 0 .4em;
  font-family: var(--serif);
  font-size: clamp(21px, 2.8vw, 28px);
  line-height: 1.42;
  letter-spacing: .01em;
}

.doc h2:first-child { margin-top: 1.6em; }

.doc h3 {
  margin: 1.8em 0 .5em;
  font: 500 17px/1.5 var(--mono);
  letter-spacing: .02em;
}

.doc p {
  font-family: var(--serif);
  font-size: 17.5px;
  line-height: 1.9;
  margin: 0 0 1.1em;
}

.doc ul,
.doc ol {
  margin: 0 0 1.2em;
  padding-left: 1.35em;
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.85;
}

.doc li { margin: .35em 0; }

.doc a {
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.doc blockquote {
  margin: 1.6em 0;
  padding: .3em 0 .3em 16px;
  border-left: 3px solid var(--ink);
  color: var(--ink-2);
}

.doc blockquote p { margin: 0 0 .6em; }
.doc blockquote p:last-child { margin-bottom: 0; }

.doc figure { margin: 1.5em 0; }
.doc img { margin: 1.3em 0; border: 1px solid var(--rule-2); border-radius: 10px; }

.doc table {
  display: block;
  overflow-x: auto;
  width: 100%;
  margin: 1.4em 0;
  border-collapse: collapse;
  font-size: 16px;
}

.doc th,
.doc td {
  border: 1px solid var(--rule-2);
  padding: 9px 11px;
  text-align: left;
}

.doc th {
  background: var(--paper-2);
  font: 500 14px/1.5 var(--mono);
}

.doc code {
  padding: 1px 5px;
  border: 1px solid var(--rule);
  border-radius: 3px;
  background: var(--paper-2);
  font-family: var(--mono);
  font-size: .92em;
}

.doc hr {
  border: 0;
  border-top: 1px solid var(--rule-2);
  margin: 2em 0;
}

.subtitle {
  margin: 0 0 1.3em;
  padding-left: 12px;
  border-left: 2px solid var(--ink);
  font: 400 15px/1.7 var(--mono);
  color: var(--ink-2);
  letter-spacing: .01em;
}

.doc h2 + .subtitle { margin-top: -.1em; }

.tail-list { margin: 0; }

/* 右栏 */
.side {
  display: grid;
  gap: 16px;
  margin-top: 34px;
  align-content: start;
}

.side-block {
  padding: 16px 16px 8px;
  border: 1px solid var(--rule-2);
  border-radius: 10px;
  background: rgba(245, 245, 245, .62);
  backdrop-filter: blur(4px);
  box-shadow: 0 1px 0 rgba(26, 26, 26, .05);
}

.side-block h2 {
  margin: 0 0 6px;
  font: 500 13px/1.5 var(--mono);
  letter-spacing: .14em;
}

.side-block .subtitle {
  margin: 0 0 12px;
  padding-left: 0;
  border-left: 0;
  font-size: 13px;
}

.side-block ol,
.side-block ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.side-block li + li { border-top: 1px solid var(--rule); }

.side-block ol a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  min-height: 40px;
  padding: 9px 0;
  text-decoration: none;
  font: 400 15px/1.5 var(--mono);
}

.side-block ol a:hover { text-decoration: underline; text-underline-offset: 3px; }

.side-block .plain li {
  padding: 8px 0;
  font-family: var(--serif);
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-2);
}

/* 页脚 */
.foot {
  margin-top: 44px;
  border-top: 1px solid var(--rule-2);
  background: var(--paper-2);
}

.foot-top {
  display: grid;
  gap: 26px;
  max-width: 1180px;
  margin: 0 auto;
  padding: 34px 18px 26px;
}

.fcol-title {
  margin: 0 0 12px;
  font: 500 12.5px/1.5 var(--mono);
  letter-spacing: .16em;
  color: var(--ink-3);
}

.foot address {
  font-style: normal;
  font-family: var(--serif);
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--ink-2);
}

.foot address strong {
  display: block;
  margin-bottom: 6px;
  font: 500 15px/1.5 var(--mono);
  color: var(--ink);
}

.foot ul { margin: 0; padding: 0; list-style: none; }

.foot ul a {
  display: flex;
  align-items: center;
  min-height: 40px;
  padding: 4px 0;
  text-decoration: none;
  font: 400 15px/1.4 var(--mono);
}

.foot ul a:hover { text-decoration: underline; text-underline-offset: 3px; }

.sub label {
  display: block;
  margin-bottom: 8px;
  font: 400 14px/1.6 var(--mono);
  color: var(--ink-2);
}

.sub input {
  width: 100%;
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid var(--rule-2);
  border-radius: 10px;
  background: var(--paper);
  color: var(--ink);
  font: 400 16px/1.5 var(--mono);
}

.sub input::placeholder { color: var(--ink-3); }

.sub button {
  width: 100%;
  min-height: 44px;
  margin-top: 10px;
  border: 1px solid var(--ink);
  border-radius: 999px;
  background: var(--ink);
  color: var(--paper);
  font: 400 15px/1.2 var(--mono);
  letter-spacing: .1em;
  cursor: pointer;
}

.sub button:hover,
.sub button:focus-visible {
  background: var(--paper);
  color: var(--ink);
}

.copyright {
  max-width: 1180px;
  margin: 0 auto;
  padding: 16px 18px 30px;
  border-top: 1px solid var(--rule);
  text-align: center;
  font: 400 13px/1.8 var(--mono);
  color: var(--ink-3);
}

/* 极简瞬间显隐 */
.rv { opacity: 0; transform: translateY(10px); }

.rv.is-in {
  opacity: 1;
  transform: none;
  transition: opacity .18s steps(3, end), transform .18s steps(3, end);
}

@media (min-width: 760px) {
  .hero {
    flex-direction: row;
    align-items: center;
    gap: 34px;
    min-height: 70vh;
    padding: 30px 0 40px;
  }

  .hero-copy { text-align: right; }
  .hero-lead { margin-left: auto; }

  .hero .badge {
    position: absolute;
    top: 18px;
    right: 0;
    margin: 0;
    z-index: 2;
  }

  .hero h1 { margin-top: 8px; }

  .foot-top { grid-template-columns: 1.4fr 1fr 1.15fr; gap: 36px; }
}

@media (min-width: 980px) {
  .sheet {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 48px;
    align-items: start;
    padding-top: 10px;
  }

  .side { margin-top: 34px; }

  .ticker { padding: 6px 26px; }
  .brandline { padding: 12px 26px; }
  .navbar { padding: 8px 26px 12px; }
  .sheet { padding-left: 26px; padding-right: 26px; }
  .foot-top { padding-left: 26px; padding-right: 26px; }
  .copyright { padding-left: 26px; padding-right: 26px; }
}

@media (max-width: 480px) {
  .pills a { font-size: 14px; padding: 10px 12px; }
  .doc p { font-size: 17px; }
}

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

button[aria-expanded]{min-width:44px;min-height:44px}