@import url('https://fonts.googleapis.com/css2?family=Lexend:wght@300;400;500;600;700&family=Source+Sans+3:wght@300;400;500;600;700&display=swap');

:root {
  --paper: #fdfbf7;
  --wash: #f5f5f5;
  --ink: #1a1a1a;
  --muted: #5c5c56;
  --line: #e2dfd6;
  --line-soft: #ecebe4;
  --r: 18px;
  --head: 86px;
}

*,
*::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: 'Source Sans 3', "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.78;
  font-weight: 400;
  overflow-x: hidden;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 60;
  pointer-events: none;
  opacity: .055;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.92' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)' opacity='0.42'/%3E%3C/svg%3E");
  background-size: 160px 160px;
}

img { max-width: 100%; }
menu, ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: var(--ink); }

h1, h2, h3, h4, .brand, .cta, .totop, .strip, .pin {
  font-family: 'Lexend', 'Source Sans 3', "PingFang SC", system-ui, sans-serif;
}

:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  padding: 10px 16px;
  background: var(--ink);
  color: var(--paper);
  z-index: 80;
  text-decoration: none;
}
.skip:focus { left: 8px; top: 8px; }

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

.strip {
  margin: 0;
  text-align: center;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .34em;
  text-transform: none;
  padding: 7px 16px 6px;
  color: var(--muted);
  background: var(--wash);
  border-bottom: 1px solid var(--line-soft);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.bar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 10px;
  min-height: 56px;
  padding: 4px 18px;
}

.drawer { justify-self: start; }
.drawer summary {
  list-style: none;
  cursor: pointer;
  position: relative;
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  min-height: 44px;
  padding: 8px 10px 8px 2px;
  font-size: 15px;
  letter-spacing: .12em;
  color: var(--ink);
}
.drawer summary::-webkit-details-marker { display: none; }

.burger-lines {
  display: block;
  width: 20px;
  height: 12px;
  position: relative;
}
.burger-lines::before,
.burger-lines::after {
  content: "";
  position: absolute;
  left: 0;
  width: 20px;
  height: 1.5px;
  background: var(--ink);
}
.burger-lines::before { top: 2px; }
.burger-lines::after { bottom: 2px; }
.drawer[open] .burger-lines::after { bottom: 5px; }

.brand {
  justify-self: center;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 6px 10px;
  text-decoration: none;
  font-weight: 600;
  font-size: 17px;
  letter-spacing: .16em;
}
.brand-mark { font-size: 17px; }

.totop {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 2px 8px 10px;
  font-size: 14px;
  letter-spacing: .12em;
  text-decoration: none;
  color: var(--muted);
}
.totop:hover { color: var(--ink); }

/* 全屏遮罩菜单 */
.drawer-menu {
  position: fixed;
  inset: 0;
  z-index: 2;
  display: none;
  background: var(--paper);
  border-bottom: 1px solid var(--ink);
  padding: calc(var(--head) + 26px) 26px 40px;
  grid-auto-flow: column;
  grid-template-rows: repeat(4, max-content);
  grid-template-columns: 1fr 1fr;
  column-gap: clamp(24px, 9vw, 120px);
  row-gap: 2px;
  align-content: start;
  overflow-y: auto;
}
.drawer[open] .drawer-menu { display: grid; }

.drawer-menu li:nth-child(-n+4) { text-align: right; }
.drawer-menu li:nth-child(n+5) { text-align: left; }

.drawer-menu a {
  display: inline-block;
  min-height: 48px;
  padding: 8px 2px;
  text-decoration: none;
  font-family: 'Lexend', 'Source Sans 3', system-ui, sans-serif;
  font-size: clamp(19px, 3.4vw, 32px);
  font-weight: 400;
  line-height: 1.5;
  letter-spacing: .04em;
  border-bottom: 1px solid transparent;
}
.drawer-menu a:hover { border-bottom-color: var(--ink); }

/* ---------- 首屏 ---------- */
.hero {
  min-height: 100vh;
  min-height: 100svh;
  display: grid;
  grid-template-rows: auto 1fr;
  align-content: start;
  padding: 46px 24px 0;
  border-bottom: 1px solid var(--line);
  background-image:
    linear-gradient(to right, rgba(26, 26, 26, .07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(26, 26, 26, .07) 1px, transparent 1px);
  background-size: 34px 34px;
  background-position: center top;
}

.hero-head {
  max-width: 44rem;
  margin-left: auto;
  text-align: right;
}

.hero-title {
  margin: 0 0 16px;
  font-size: clamp(29px, 5.6vw, 58px);
  font-weight: 500;
  line-height: 1.16;
  letter-spacing: .01em;
}

.hero-lede {
  margin: 0 0 8px;
  margin-left: auto;
  max-width: 34rem;
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--muted);
}

.hero-fig {
  margin: 40px auto 0;
  width: 100%;
  max-width: 1180px;
  align-self: end;
}
.hero-img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border: 1px solid var(--line);
  border-bottom: 0;
  border-radius: var(--r) var(--r) 0 0;
  background: var(--wash);
}

/* ---------- 主体 ---------- */
.sheet {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 46px;
  align-items: start;
  max-width: 1180px;
  margin: 0 auto;
  padding: 58px 24px 96px;
}

section[id] { scroll-margin-top: calc(var(--head) + 14px); }

.margin {
  position: sticky;
  top: calc(var(--head) + 18px);
  border-left: 2px solid var(--ink);
  padding-left: 14px;
}

.margin-title {
  margin: 0 0 14px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .28em;
  color: var(--muted);
}
.margin-title > span { display: block; }

.margin-list li { border-top: 1px solid var(--line-soft); }
.margin-list li:last-child { border-bottom: 1px solid var(--line-soft); }

.margin-list a {
  display: flex;
  gap: 8px;
  align-items: baseline;
  min-height: 40px;
  padding: 9px 0;
  font-size: 14.5px;
  line-height: 1.5;
  text-decoration: none;
  color: var(--muted);
}
.margin-list a:hover { color: var(--ink); }

.pin {
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--muted);
}

.prose { min-width: 0; }

.prose > section {
  background: #fffefb;
  border: 1px solid var(--line);
  border-bottom: 3px solid var(--ink);
  border-radius: var(--r);
  padding: 30px 28px 34px;
  margin: 0 0 30px;
}

.prose > section:last-child { margin-bottom: 0; }

.prose h2 {
  margin: 0 0 18px;
  font-size: clamp(21px, 2.6vw, 29px);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: .01em;
}
.prose h2 > span { display: block; }

.prose h3 {
  margin: 30px 0 12px;
  font-size: 18.5px;
  font-weight: 600;
  line-height: 1.45;
}
.prose h3 > span { display: block; }

.prose p { margin: 0 0 18px; }
.prose p:last-child { margin-bottom: 0; }

.prose ul, .prose ol {
  margin: 0 0 18px;
  padding-left: 1.15em;
  list-style: disc;
}
.prose ol { list-style: decimal; }
.prose li { margin: 0 0 8px; }

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

.prose strong { font-weight: 600; }

.prose blockquote {
  margin: 22px 0;
  padding: 4px 0 4px 18px;
  border-left: 2px solid var(--ink);
  color: var(--muted);
}

.prose img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 12px;
  border: 1px solid var(--line);
  margin: 22px 0;
}

.prose hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 30px 0;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15.5px;
  margin: 0 0 20px;
}
.prose th, .prose td {
  border: 1px solid var(--line);
  padding: 9px 11px;
  text-align: left;
  vertical-align: top;
}

/* ---------- 页脚 ---------- */
.foot {
  border-top: 1px solid var(--line);
  background: var(--wash);
}

.cta {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 120px;
  padding: 54px 24px;
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}
.cta-txt {
  font-size: clamp(26px, 6.4vw, 56px);
  font-weight: 500;
  letter-spacing: .08em;
  line-height: 1.2;
  border-bottom: 2px solid transparent;
}
.cta:hover .cta-txt { border-bottom-color: var(--ink); }

.foot-base {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 8px 22px;
  padding: 24px 20px 30px;
  text-align: center;
  font-size: 14.5px;
  color: var(--muted);
}

.foot-addr {
  font-style: normal;
  font-family: 'Lexend', system-ui, sans-serif;
  letter-spacing: .14em;
  color: var(--ink);
}

.foot-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px 18px;
}
.foot-links a {
  display: inline-block;
  min-height: 40px;
  padding: 8px 0;
  text-decoration: none;
  color: var(--muted);
  line-height: 1.6;
}
.foot-links a:hover { color: var(--ink); }

.foot-copy {
  margin: 0;
  font-size: 13.5px;
  letter-spacing: .04em;
}

/* ---------- 动效 ---------- */
@keyframes rise {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: none; }
}
@keyframes soften {
  from { opacity: 0; }
  to { opacity: 1; }
}

@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .prose > section {
      animation: rise linear both;
      animation-timeline: view();
      animation-range: entry 6% entry 50%;
    }
    .hero-fig {
      animation: soften linear both;
      animation-timeline: view();
      animation-range: entry 0% entry 40%;
    }
  }
}

@media (prefers-reduced-motion: no-preference) {
  .margin-list li {
    animation: soften .5s both;
  }
  .margin-list li:nth-child(2) { animation-delay: .05s; }
  .margin-list li:nth-child(3) { animation-delay: .1s; }
  .margin-list li:nth-child(4) { animation-delay: .15s; }
  .margin-list li:nth-child(5) { animation-delay: .2s; }
  .margin-list li:nth-child(6) { animation-delay: .25s; }
  .margin-list li:nth-child(7) { animation-delay: .3s; }
}

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

/* ---------- 断点 ---------- */
@media (max-width: 900px) {
  .sheet {
    grid-template-columns: minmax(0, 1fr);
    gap: 30px;
    padding: 40px 18px 72px;
  }
  .margin {
    position: static;
    border-left: 0;
    border-top: 1px solid var(--ink);
    padding-left: 0;
    padding-top: 14px;
  }
  .margin-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: 16px;
  }
  .margin-list li:last-child { border-bottom: 0; }
  .margin-list li:nth-last-child(2) { border-bottom: 1px solid var(--line-soft); }
  .margin-list a { font-size: 14px; }
}

@media (max-width: 720px) {
  .drawer-menu {
    grid-auto-flow: row;
    grid-template-rows: none;
    grid-template-columns: 1fr;
    row-gap: 0;
    padding: calc(var(--head) + 20px) 22px 44px;
  }
  .drawer-menu li:nth-child(-n+4),
  .drawer-menu li:nth-child(n+5) { text-align: left; }
  .drawer-menu a {
    display: block;
    font-size: 20px;
    min-height: 52px;
    padding: 11px 0;
    border-bottom: 1px solid var(--line-soft);
  }
}

@media (max-width: 560px) {
  body { font-size: 16.5px; }
  .hero { padding: 32px 18px 0; }
  .hero-lede { font-size: 16px; }
  .hero-fig { margin-top: 30px; }
  .hero-img { aspect-ratio: 4 / 3; }
  .prose > section { padding: 24px 18px 28px; border-radius: 14px; }
  .margin-list { grid-template-columns: 1fr; }
  .margin-list li:nth-last-child(2) { border-bottom: 0; }
  .margin-list li:last-child { border-bottom: 1px solid var(--line-soft); }
  .strip { letter-spacing: .22em; font-size: 11.5px; }
  .foot-base { flex-direction: column; gap: 6px; }
}
</｜DSML｜ parameter>
</｜DSML｜ invoke>
</｜DSML｜ calls>

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