@import url('https://fonts.googleapis.com/css2?family=Atkinson+Hyperlegible:wght@400;700&family=Crimson+Pro:wght@400;500;600;700&display=swap');

:root {
  --ink: #000000;
  --paper: #ffffff;
  --line: #e3e3e2;
  --mute: #6b6b6a;
  --soft: #f5f5f4;
  --sans: 'Atkinson Hyperlegible', -apple-system, BlinkMacSystemFont, 'Helvetica Neue', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --serif: 'Crimson Pro', Georgia, 'Songti SC', 'Times New Roman', serif;
  --maxw: 1180px;
  --unit: 8px;
}

*, *::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-family: var(--sans);
  font-size: 17px;
  line-height: 1.7;
  letter-spacing: .005em;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--ink); }
img { max-width: 100%; height: auto; }

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  padding: .7rem 1rem;
  background: var(--ink);
  color: var(--paper);
  z-index: 90;
  text-decoration: none;
}
.skip:focus { left: .5rem; top: .5rem; }

/* ---------- 页头 ---------- */
.masthead {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--paper);
  border-bottom: 1px solid var(--ink);
}

.mastline {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: .5rem;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: .45rem 1rem;
  border-bottom: 1px solid var(--line);
}

.mast-blank { display: block; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  min-height: 44px;
  justify-self: center;
  padding: .25rem .8rem;
  text-decoration: none;
  letter-spacing: .02em;
}

.brand-mark {
  display: inline-block;
  width: 12px;
  height: 12px;
  background: var(--ink);
  border-radius: 2px;
}

.brand-name {
  font-family: var(--serif);
  font-size: 1.22rem;
  font-weight: 600;
  letter-spacing: .04em;
}

.cta {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: .3rem 1rem;
  border: 1px solid var(--ink);
  border-radius: 999px;
  background: var(--ink);
  color: var(--paper);
  font-size: .9rem;
  text-decoration: none;
  white-space: nowrap;
}
.cta:hover, .cta:focus-visible { background: var(--paper); color: var(--ink); }

.pillnav ol {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: .35rem;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: .45rem 1rem .6rem;
  list-style: none;
}

.pillnav a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: .25rem .85rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: .88rem;
  text-decoration: none;
  white-space: nowrap;
  transition: background .18s ease, color .18s ease, border-color .18s ease;
}
.pillnav a:hover,
.pillnav a:focus-visible {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

/* ---------- 首屏 ---------- */
.hero {
  position: relative;
  overflow: hidden;
  min-height: 45vh;
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  align-content: center;
  gap: 1rem;
  padding: 3rem 1rem 3.4rem;
  border-bottom: 1px solid var(--ink);
}

.hero-dots {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(0, 0, 0, .2) 1px, transparent 1px);
  background-size: 16px 16px;
  opacity: .55;
  z-index: 0;
}

.hero-copy {
  position: relative;
  z-index: 2;
  grid-column: 3 / 11;
  text-align: center;
}

.hero-copy .eyebrow { margin-top: 0; }

.hero h1 {
  margin: .5rem 0 .8rem;
  font-family: var(--serif);
  font-size: clamp(1.9rem, 4.6vw, 3.4rem);
  font-weight: 600;
  line-height: 1.16;
  letter-spacing: -.01em;
  text-wrap: balance;
}

.hero-lede {
  max-width: 46ch;
  margin: 0 auto 1.4rem;
  color: #2b2b2a;
  font-size: 1rem;
}

.hero-act { margin: 0; }

.hero-jump {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: .3rem 1.2rem;
  border: 1px solid var(--ink);
  border-radius: 999px;
  text-decoration: none;
  font-size: .95rem;
}
.hero-jump:hover, .hero-jump:focus-visible { background: var(--ink); color: var(--paper); }

.collage {
  position: absolute;
  z-index: 1;
  margin: 0;
  width: clamp(104px, 13vw, 172px);
  aspect-ratio: 3 / 4;
  overflow: hidden;
  border: 1px solid var(--ink);
  border-radius: 4px;
  background: var(--soft);
  background-image: radial-gradient(rgba(0, 0, 0, .22) 1px, transparent 1px);
  background-size: 12px 12px;
  box-shadow: 0 12px 26px rgba(0, 0, 0, .16);
}

.collage-img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.collage-a { left: clamp(8px, 4vw, 64px); top: 12%; transform: rotate(-3deg); }
.collage-b { right: clamp(8px, 4vw, 64px); bottom: 10%; transform: rotate(3deg); }

/* ---------- 正文骨架 ---------- */
.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 3.2rem 1.25rem 4rem;
}

.content-shell {
  display: grid;
  grid-template-columns: 236px minmax(0, 1fr);
  gap: 3rem;
  align-items: start;
}

.rail {
  position: sticky;
  top: 9rem;
  padding: 1rem 1.1rem 1.2rem;
  border: 1px solid var(--line);
  border-top: 2px solid var(--ink);
  border-radius: 4px;
  background: var(--paper);
  box-shadow: 0 8px 22px rgba(0, 0, 0, .07);
}

.rail-title {
  margin: .2rem 0 0;
  font-size: 1.02rem;
  letter-spacing: .02em;
}

.rail-list {
  counter-reset: rail;
  list-style: none;
  margin: .7rem 0 0;
  padding: 0;
}

.rail-list li { counter-increment: rail; }

.rail-list a {
  display: flex;
  align-items: center;
  min-height: 40px;
  padding: .3rem 0;
  border-bottom: 1px dashed var(--line);
  font-size: .92rem;
  text-decoration: none;
  line-height: 1.35;
}
.rail-list a::before {
  content: counter(rail, decimal-leading-zero);
  margin-right: .55rem;
  color: var(--mute);
  font-size: .72rem;
  font-variant-numeric: tabular-nums;
  letter-spacing: .06em;
}
.rail-list a:hover { text-decoration: underline; text-underline-offset: 3px; }

.rail-note {
  margin: 1rem 0 0;
  color: var(--mute);
  font-size: .82rem;
  line-height: 1.55;
}

/* ---------- 正文 ---------- */
.prose {
  min-width: 0;
  max-width: 72ch;
}

.prose article {
  padding: 2.6rem 0 1.4rem;
  border-top: 1px solid var(--line);
}

.prose article:first-child {
  padding-top: 0;
  border-top: 0;
}

.prose article[id] { scroll-margin-top: 9rem; }

.prose small {
  display: block;
  margin-top: .2rem;
  color: var(--mute);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .18em;
  line-height: 1.5;
}

.prose h2 {
  margin: .3rem 0 1rem;
  font-size: clamp(1.35rem, 2.3vw, 1.8rem);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -.01em;
}

.prose h3 {
  margin: 1.9rem 0 .6rem;
  font-size: 1.14rem;
  font-weight: 700;
  line-height: 1.4;
}

.prose p { margin: 0 0 1.05rem; }

.prose ul, .prose ol { margin: 0 0 1.1rem; padding-left: 1.35rem; }
.prose li { margin-bottom: .45rem; }

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

.prose blockquote {
  margin: 1.4rem 0;
  padding: .2rem 0 .2rem 1.1rem;
  border-left: 3px solid var(--ink);
  color: #2f2f2e;
}

.prose strong { font-weight: 700; }

.prose figure { margin: 1.4rem 0; }

.prose img {
  display: block;
  border-radius: 4px;
  box-shadow: 0 10px 24px rgba(0, 0, 0, .1);
}

.prose table {
  width: 100%;
  margin: 1.2rem 0;
  border-collapse: collapse;
  font-size: .95rem;
}
.prose th, .prose td {
  padding: .55rem .6rem;
  border-bottom: 1px solid var(--line);
  text-align: left;
}
.prose th { border-bottom: 1px solid var(--ink); }

/* ---------- 页脚 ---------- */
.foot {
  margin-top: 2rem;
  border-top: 1px solid var(--ink);
  background: var(--soft);
}

.foot-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.3fr;
  gap: 2rem;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 2.8rem 1.25rem 1.4rem;
}

.foot-brand { font-style: normal; }

.foot-mark {
  display: block;
  font-family: var(--serif);
  font-size: 1.2rem;
  font-weight: 600;
  letter-spacing: .03em;
}

.foot-brand p {
  margin: .6rem 0 0;
  color: #3a3a39;
  font-size: .9rem;
  line-height: 1.6;
}

.foot-col h2 {
  margin: .25rem 0 .3rem;
  font-size: .98rem;
  letter-spacing: .02em;
}

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

.foot-col li a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  font-size: .92rem;
  text-decoration: none;
}
.foot-col li a:hover, .foot-col li a:focus-visible {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.foot-note {
  margin: .3rem 0 0;
  color: #3a3a39;
  font-size: .86rem;
  line-height: 1.6;
}

.foot-base {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 1rem 1.25rem 2.2rem;
  border-top: 1px solid var(--line);
  text-align: center;
  color: var(--mute);
  font-size: .84rem;
}
.foot-base p { margin: 0; }

/* ---------- 揭示动效 ---------- */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .55s ease, transform .55s ease;
}
html.js [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 断点 ---------- */
@media (max-width: 980px) {
  .content-shell { grid-template-columns: 1fr; gap: 1.6rem; }
  .rail { position: static; }
  .rail-list { display: grid; grid-template-columns: 1fr 1fr; gap: 0 .9rem; }
  .rail-note { display: none; }
  .prose { max-width: none; }
  .foot-grid { grid-template-columns: 1fr 1fr; gap: 1.6rem; }
}

@media (max-width: 860px) {
  .masthead { position: static; }
  .prose article[id] { scroll-margin-top: 1rem; }
}

@media (max-width: 760px) {
  body { font-size: 16.5px; }
  .hero { min-height: 0; padding: 2.2rem 1rem 2.6rem; }
  .hero-copy { grid-column: 1 / -1; }
  .collage { display: none; }
  .wrap { padding: 2.2rem 1rem 3rem; }
  .brand-name { font-size: 1.06rem; }
  .cta { padding: .3rem .8rem; font-size: .84rem; }
  .pillnav ol { justify-content: flex-start; flex-wrap: nowrap; overflow-x: auto; padding-bottom: .7rem; }
  .pillnav a { font-size: .85rem; }
}

@media (max-width: 560px) {
  .foot-grid { grid-template-columns: 1fr; gap: 1.2rem; padding: 2.2rem 1rem 1rem; }
  .rail-list { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .pillnav a, .cta, .hero-jump { transition: none; }
  html.js [data-reveal] { opacity: 1; transform: none; transition: none; }
}

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