@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@300;400;500;600;700&display=swap');

:root {
  --ink: #000000;
  --paper: #ffffff;
  --grey: #3a3a3a;
  --line: #000000;
  --soft: #ededed;
  --dock: 150px;
}

*, *::before, *::after { box-sizing: border-box; border-radius: 0; }

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

body {
  margin: 0;
  padding-bottom: var(--dock);
  background: var(--paper);
  color: var(--ink);
  font-family: 'IBM Plex Sans', -apple-system, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.72;
  font-weight: 400;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; height: auto; }
p { margin: 0 0 1.05rem; }
p:last-child { margin-bottom: 0; }
strong, b { font-weight: 600; }
:focus-visible { outline: 3px solid var(--ink); outline-offset: 2px; }

.skip {
  position: absolute;
  left: 1rem;
  top: -6rem;
  z-index: 200;
  background: var(--ink);
  color: var(--paper);
  padding: .6rem 1rem;
  transition: top .18s ease;
}
.skip:focus { top: .5rem; }

/* ---------- 底部固定条 ---------- */
.dock {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 120;
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-areas: "b b" "l r";
  align-items: center;
  column-gap: .3rem;
  padding: .2rem clamp(.4rem, 2vw, 1.3rem);
  background: var(--paper);
  border-top: 2px solid var(--line);
}

.dock-brand {
  grid-area: b;
  margin: 0;
  text-align: center;
  padding: .1rem 0;
}

.brand {
  display: inline-block;
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: .04em;
  padding: .45rem 1.1rem;
  border-left: 2px solid var(--line);
  border-right: 2px solid var(--line);
  min-height: 40px;
}

.dock-nav { overflow: hidden; }
.dock-nav--left { grid-area: l; }
.dock-nav--right { grid-area: r; }
.dock-nav p {
  display: flex;
  flex-wrap: wrap;
  margin: 0;
  gap: 0 .1rem;
}
.dock-nav--left p { justify-content: flex-start; }
.dock-nav--right p { justify-content: flex-end; }

.dock-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: .35rem .42rem;
  font-size: 16px;
  letter-spacing: -.01em;
  line-height: 1.2;
}
.dock-nav a:hover,
.dock-nav a:focus-visible { background: var(--ink); color: var(--paper); }

.dock-more {
  position: absolute;
  right: clamp(.35rem, 2vw, 1.1rem);
  top: .3rem;
}
.dock-more summary {
  list-style: none;
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 .7rem;
  border: 2px solid var(--line);
  font-size: 16px;
  cursor: pointer;
  background: var(--paper);
}
.dock-more summary::-webkit-details-marker { display: none; }
.dock-more[open] summary { background: var(--ink); color: var(--paper); }

.more-panel {
  position: absolute;
  right: 0;
  bottom: calc(100% + .55rem);
  width: min(80vw, 310px);
  background: var(--ink);
  color: var(--paper);
  padding: 1rem;
  display: grid;
  gap: .65rem;
  border: 2px solid var(--line);
}
.more-panel .search { display: flex; gap: .4rem; }
.more-panel input {
  flex: 1 1 auto;
  min-width: 0;
  min-height: 42px;
  padding: .3rem .55rem;
  border: 2px solid var(--paper);
  background: var(--ink);
  color: var(--paper);
  font: inherit;
  font-size: 16px;
}
.more-panel input::placeholder { color: #bdbdbd; }
.more-panel button {
  min-height: 42px;
  padding: 0 .75rem;
  border: 2px solid var(--paper);
  background: var(--paper);
  color: var(--ink);
  font: inherit;
  font-size: 16px;
  cursor: pointer;
}
.more-panel :focus-visible { outline-color: var(--paper); }
.search-state { margin: 0; font-size: 16px; min-height: 1.2em; color: #d6d6d6; }
.more-h {
  margin: 0;
  font-size: 16px;
  letter-spacing: .26em;
  border-bottom: 1px solid #4a4a4a;
  padding-bottom: .3rem;
}
.more-links { display: flex; flex-wrap: wrap; gap: 0 .55rem; margin: 0; }
.more-links a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  font-size: 16px;
  border-bottom: 1px solid #5a5a5a;
}
.more-links a:hover { border-bottom-color: var(--paper); }

/* ---------- 主体 ---------- */
main {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 clamp(.9rem, 4vw, 2.6rem);
  counter-reset: sec;
}

main > div { scroll-margin-top: 1rem; scroll-margin-bottom: 160px; }
main > div.hit { outline: 4px solid var(--ink); outline-offset: -4px; }

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.2rem;
  padding: 1rem 0 1.4rem;
  position: relative;
}

.hero-media {
  margin: 0;
  background: var(--ink);
  min-height: 34vh;
  overflow: hidden;
}
.hero-media img {
  width: 100%;
  height: 100%;
  min-height: 34vh;
  object-fit: cover;
  transform: scale(1.06);
  will-change: transform;
}

.hero-copy { text-align: right; }

.badge {
  display: inline-block;
  background: var(--ink);
  color: var(--paper);
  font-size: 16px;
  line-height: 1;
  padding: .55rem .8rem;
  letter-spacing: .16em;
  transform: translateX(.35rem);
}

.hero h1 {
  margin: .7rem 0 .5rem;
  font-size: clamp(2.3rem, 10vw, 4.4rem);
  line-height: 1.02;
  letter-spacing: -.035em;
  font-weight: 700;
  word-break: break-word;
}

.subtitle {
  margin: 0;
  font-size: 16px;
  line-height: 1.6;
  color: var(--grey);
  max-width: 46ch;
  margin-left: auto;
}

/* 正文区 */
main > div:not(.hero) {
  counter-increment: sec;
  border-top: 2px solid var(--line);
  padding: 1.8rem 0 1.4rem;
}

main > div:not(.hero) > h2 {
  margin: 0 0 .85rem;
  font-size: clamp(1.45rem, 4.6vw, 2.1rem);
  line-height: 1.14;
  letter-spacing: -.02em;
  font-weight: 700;
}
main > div:not(.hero) > h2::before {
  content: counter(sec, decimal-leading-zero);
  display: block;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .3em;
  margin-bottom: .35rem;
}

main > div:not(.hero) > h3 {
  margin: 1.4rem 0 .5rem;
  font-size: 1.18rem;
  line-height: 1.3;
  letter-spacing: -.01em;
}

main > div:not(.hero) > p:first-of-type::first-letter {
  float: left;
  font-size: 3.2em;
  line-height: .84;
  font-weight: 700;
  padding: .06em .12em 0 0;
}

main h2 { font-weight: 700; }
main h4 { font-size: 1.05rem; margin: 1.2rem 0 .4rem; }

main ul, main ol { margin: 0 0 1.15rem; padding-left: 1.3rem; }
main li { margin-bottom: .4rem; }
main li::marker { font-weight: 600; }

main blockquote {
  margin: 1.5rem 0;
  padding: .9rem 0 .9rem 1.1rem;
  border-left: 7px solid var(--line);
  font-size: 1.22rem;
  line-height: 1.46;
  font-weight: 500;
}
main blockquote p:last-child { margin-bottom: 0; }

main figure { margin: 1.4rem 0; }
main figure img { width: 100%; }
main figcaption {
  font-size: 16px;
  color: var(--grey);
  border-top: 1px solid var(--line);
  padding-top: .35rem;
  margin-top: .5rem;
}

main table { width: 100%; border-collapse: collapse; margin: 1.3rem 0; font-size: 16px; }
main th, main td { border: 1px solid var(--line); padding: .5rem .6rem; text-align: left; }
main th { background: var(--soft); }
main code, main pre { font-family: 'IBM Plex Mono', ui-monospace, monospace; font-size: 15px; }
main pre { overflow-x: auto; padding: .8rem; background: var(--soft); }
main hr { border: 0; border-top: 2px solid var(--line); margin: 1.6rem 0; }

/* ---------- 右栏 ---------- */
.rail {
  background: var(--ink);
  color: var(--paper);
  padding: 1.2rem 1.1rem 1.1rem;
  margin: 1.6rem 0 2rem;
}
.rail h2 {
  margin: 0;
  font-size: 1rem;
  letter-spacing: .3em;
  font-weight: 600;
}
.rail .subtitle {
  color: #bcbcbc;
  margin: .25rem 0 .9rem;
  max-width: none;
  margin-left: 0;
}
.rail ol { list-style: none; margin: 0; padding: 0; }
.rail li { border-top: 1px solid #454545; margin: 0; }
.rail li a {
  display: flex;
  align-items: center;
  gap: .65rem;
  min-height: 44px;
  padding: .3rem 0;
  font-size: 16px;
  counter-increment: rail;
}
.rail ol { counter-reset: rail; }
.rail li a::before {
  content: counter(rail, decimal-leading-zero);
  font-size: 15px;
  font-weight: 600;
  color: #9a9a9a;
  letter-spacing: .1em;
}
.rail li a:hover, .rail li a:focus-visible { color: #ffffff; text-decoration: underline; }
.rail :focus-visible { outline-color: var(--paper); }
.rail-top { margin: 1rem 0 0; }
.rail-top a {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 0 .8rem;
  border: 2px solid var(--paper);
  font-size: 16px;
}
.rail-top a:hover { background: var(--paper); color: var(--ink); }

/* ---------- 页脚 ---------- */
.foot { margin-top: 2.4rem; border-top: 2px solid var(--line); }

.foot-cta {
  background: var(--ink);
  color: var(--paper);
  padding: 2rem clamp(.9rem, 4vw, 2.6rem) 1.8rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: flex-end;
  justify-content: space-between;
}
.cta-brand {
  margin: 0;
  font-size: clamp(1.9rem, 8vw, 3.2rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
}
.cta-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 1rem;
  background: var(--paper);
  color: var(--ink);
  font-size: 16px;
  font-weight: 500;
}

.foot-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .4rem 1.2rem;
  padding: .8rem clamp(.9rem, 4vw, 2.6rem) 1.2rem;
  border-top: 1px solid var(--line);
}
.foot-brand { font-weight: 700; letter-spacing: .04em; font-size: 16px; padding: .55rem 0; }
.foot-nav p { display: flex; flex-wrap: wrap; gap: 0 .9rem; margin: 0; }
.foot-nav a { display: inline-flex; align-items: center; min-height: 44px; font-size: 16px; border-bottom: 2px solid transparent; }
.foot-nav a:hover { border-bottom-color: var(--line); }
.foot-copy { margin: 0; font-size: 16px; color: var(--grey); }

/* ---------- 断点 ---------- */
@media (min-width: 700px) {
  .hero {
    grid-template-columns: 1.06fr .94fr;
    align-items: end;
    gap: 2.2rem;
    min-height: 66vh;
    padding: 2rem 0 2.4rem;
  }
  .hero-media, .hero-media img { min-height: 52vh; }
  .subtitle { font-size: 17px; }
  .badge { font-size: 16px; }
}

@media (min-width: 860px) {
  :root { --dock: 92px; }
  body { padding-bottom: var(--dock); }
  .dock {
    grid-template-columns: 1fr auto 1fr;
    grid-template-areas: "l b r";
    padding: .35rem clamp(1rem, 3vw, 2rem);
  }
  .dock-brand { grid-area: b; }
  .dock-nav p { flex-wrap: nowrap; }
  .dock-nav--right { padding-right: 4.6rem; }
  .dock-more { top: 50%; transform: translateY(-50%); }
  main > div { scroll-margin-bottom: 110px; }
}

@media (min-width: 1024px) {
  main {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 19rem;
    column-gap: 3rem;
    align-items: start;
    padding-top: .5rem;
  }
  main > .hero { grid-column: 1 / -1; }
  main > aside {
    grid-column: 2;
    grid-row: 2 / span 400;
    align-self: start;
    position: sticky;
    top: 1.5rem;
    margin-top: 2rem;
  }
  main > div:not(.hero) { columns: 2; column-gap: 2.6rem; }
  main > div:not(.hero) > h2,
  main > div:not(.hero) > h3,
  main > div:not(.hero) > h4,
  main > div:not(.hero) > figure,
  main > div:not(.hero) > blockquote,
  main > div:not(.hero) > ul,
  main > div:not(.hero) > ol,
  main > div:not(.hero) > table,
  main > div:not(.hero) > pre,
  main > div:not(.hero) > hr { column-span: all; }
  main > div:not(.hero) > p:first-of-type { margin-top: 0; }
}

@media (min-width: 1180px) {
  .hero { min-height: 70vh; }
}

@media (prefers-reduced-motion: no-preference) {
  .js main > div:not(.hero) {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity .55s ease, transform .55s ease;
  }
  .js main > div.in { opacity: 1; transform: none; }
}

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

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