:root {
  --ink: #000;
  --paper: #fff;
  --muted: #525252;
  --faint: #8f8f8f;
  --line: rgba(0, 0, 0, 0.14);
  --glass: rgba(255, 255, 255, 0.74);
  --display: 'Anton', Impact, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --body: 'Epilogue', 'Helvetica Neue', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --r: 18px;
}

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

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

body {
  margin: 0;
  background-color: var(--paper);
  background-image: radial-gradient(rgba(0, 0, 0, 0.11) 1px, transparent 1px);
  background-size: 24px 24px;
  color: var(--ink);
  font-family: var(--body);
  font-size: 17px;
  line-height: 1.7;
  letter-spacing: 0.01em;
}

img { max-width: 100%; height: auto; }

a { color: var(--ink); }

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

.sr {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

.skip {
  position: absolute;
  left: 0;
  top: 0;
  transform: translateY(-140%);
  background: var(--ink);
  color: #fff;
  padding: 12px 20px;
  font-weight: 700;
  text-decoration: none;
  z-index: 200;
  border-radius: 0 0 12px 0;
}
.skip:focus { transform: none; }

/* ---------- 顶栏 ---------- */
.top {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 14px;
  padding: 12px 22px;
  border-bottom: 2px solid var(--ink);
  background: rgba(255, 255, 255, 0.88);
  position: relative;
  z-index: 40;
}

.brand {
  justify-self: center;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 6px 4px;
  font-family: var(--display);
  font-size: 1.4rem;
  letter-spacing: 0.02em;
  text-decoration: none;
  color: var(--ink);
}
.brand .mark {
  width: 13px;
  height: 13px;
  background: var(--ink);
  border-radius: 3px;
  transform: rotate(45deg);
  display: block;
}

.drawer {
  justify-self: start;
  position: relative;
}
.drawer > summary {
  list-style: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  min-height: 44px;
  padding: 6px 16px;
  border: 2px solid var(--ink);
  border-radius: 999px;
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.06em;
}
.drawer > summary::-webkit-details-marker { display: none; }
.drawer > summary::after {
  content: "+";
  font-weight: 700;
  font-size: 1.15rem;
  line-height: 1;
}
.drawer[open] > summary {
  background: var(--ink);
  color: #fff;
}
.drawer[open] > summary::after { content: "–"; }

.drawer-list {
  position: absolute;
  top: calc(100% + 12px);
  left: 0;
  margin: 0;
  padding: 10px;
  list-style: none;
  min-width: 236px;
  background: #fff;
  border: 2px solid var(--ink);
  border-radius: var(--r);
  box-shadow: 10px 10px 0 var(--ink);
  z-index: 60;
}
.drawer-list li + li { border-top: 1px solid var(--line); }

.dlink {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 10px;
  font-weight: 600;
  text-decoration: none;
  border-radius: 10px;
}
.dlink:hover, .dlink:focus-visible {
  background: var(--ink);
  color: #fff;
}

/* 搜索 */
.find {
  justify-self: end;
  display: flex;
  align-items: center;
  border: 2px solid var(--ink);
  border-radius: 999px;
  overflow: hidden;
  background: #fff;
}
.find input {
  border: 0;
  background: transparent;
  font: inherit;
  font-size: 16px;
  padding: 10px 14px;
  width: 148px;
  min-height: 44px;
  outline-offset: -4px;
}
.find button {
  border: 0;
  background: var(--ink);
  color: #fff;
  font: inherit;
  font-weight: 700;
  font-size: 16px;
  padding: 0 18px;
  min-height: 48px;
  cursor: pointer;
}

/* ---------- 粘性锚点条 ---------- */
.rail {
  position: sticky;
  top: 0;
  z-index: 30;
  background: #fff;
  border-bottom: 2px solid var(--ink);
}
.rail ul {
  display: flex;
  margin: 0 auto;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  counter-reset: step;
  max-width: 1180px;
  scrollbar-width: none;
}
.rail ul::-webkit-scrollbar { display: none; }
.rail li { flex: 0 0 auto; }

.rlink {
  display: flex;
  align-items: center;
  gap: 7px;
  min-height: 48px;
  padding: 10px 16px;
  font-size: 16px;
  font-weight: 700;
  text-decoration: none;
  white-space: nowrap;
  border-right: 1px solid var(--line);
}
.rlink::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  font-family: var(--display);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--faint);
}
.rlink:hover, .rlink:focus-visible {
  background: var(--ink);
  color: #fff;
}
.rlink:hover::before, .rlink:focus-visible::before { color: #fff; }

/* ---------- 主体骨架 ---------- */
.wrap {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 22px;
}

.stage {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 264px;
  gap: 44px;
  align-items: start;
  padding-top: 34px;
}

/* ---------- 首屏 ---------- */
.hero {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 40px;
  align-items: center;
  min-height: calc(100vh - 200px);
  padding: 16px 0 52px;
}
.hero-copy {
  min-width: 0;
  text-align: center;
}
.eyebrow {
  margin: 0 0 18px;
  font-size: 0.92rem;
  font-weight: 700;
  letter-spacing: 0.34em;
  text-transform: uppercase;
}
h1 {
  margin: 0 0 22px;
  font-family: var(--display);
  font-weight: 900;
  font-size: clamp(2.9rem, 9vw, 7.4rem);
  line-height: 0.9;
  letter-spacing: -0.04em;
  word-break: break-word;
}
.lead {
  margin: 0 auto;
  max-width: 30ch;
  font-size: 1.05rem;
  line-height: 1.7;
  color: #2e2e2e;
}
.cta-row { margin: 28px 0 0; }
.cta {
  display: inline-flex;
  align-items: center;
  min-height: 48px;
  padding: 12px 32px;
  background: var(--ink);
  color: #fff;
  border-radius: 999px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-decoration: none;
}
.cta:hover { outline: 3px solid var(--ink); outline-offset: 3px; }

.hero-visual {
  position: relative;
  aspect-ratio: 1 / 1.06;
  border-radius: var(--r);
  overflow: hidden;
  background-color: var(--ink);
  background-image: radial-gradient(rgba(255, 255, 255, 0.5) 1.5px, transparent 1.5px);
  background-size: 20px 20px;
}
.hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  filter: grayscale(1) contrast(1.08);
}
.ring {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 56%;
  aspect-ratio: 1;
  translate: -50% -50%;
  border: 2px solid #fff;
  border-radius: 50%;
}
.ring.r2 { width: 86%; opacity: 0.55; }
.cube {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 33%;
  aspect-ratio: 1;
  translate: -50% -50%;
  rotate: 45deg;
  background: #fff;
}

/* ---------- 正文 ---------- */
.body-col { min-width: 0; }

.body-col > div {
  scroll-margin-top: 88px;
  margin: 0 0 26px;
  padding: 38px 34px;
  border: 1.5px solid var(--line);
  border-radius: var(--r);
  background: var(--glass);
  -webkit-backdrop-filter: blur(12px) saturate(1.05);
  backdrop-filter: blur(12px) saturate(1.05);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.04);
}

.body-col h2 {
  margin: 0 0 14px;
  font-family: var(--display);
  font-weight: 900;
  font-size: clamp(1.7rem, 4vw, 2.55rem);
  line-height: 1.06;
  letter-spacing: -0.03em;
}
.body-col h3 {
  margin: 26px 0 10px;
  font-family: var(--display);
  font-size: 1.22rem;
  line-height: 1.25;
  letter-spacing: -0.01em;
}
.body-col p { margin: 0 0 16px; }
.body-col p:last-child { margin-bottom: 0; }
.body-col .subtitle {
  margin: -6px 0 18px;
  color: var(--muted);
  font-size: 1rem;
}
.body-col ul, .body-col ol {
  margin: 0 0 18px;
  padding-left: 1.3em;
}
.body-col li { margin: 0 0 8px; }
.body-col a {
  font-weight: 600;
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}
.body-col a:hover {
  background: var(--ink);
  color: #fff;
  text-decoration: none;
}
.body-col strong {
  font-weight: 800;
  background: linear-gradient(transparent 62%, rgba(0, 0, 0, 0.14) 62%);
}
.body-col blockquote {
  margin: 20px 0;
  padding: 14px 20px;
  border-left: 6px solid var(--ink);
  border-radius: 0 12px 12px 0;
  background: rgba(0, 0, 0, 0.035);
}
.body-col blockquote p:last-child { margin-bottom: 0; }
.body-col img { border-radius: 12px; }

/* ---------- 侧栏 ---------- */
.side {
  position: sticky;
  top: 72px;
  padding: 24px 22px;
  border: 1.5px solid var(--line);
  border-radius: var(--r);
  background: var(--glass);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}
.side h2 {
  margin: 0 0 6px;
  font-family: var(--display);
  font-size: 1.32rem;
  letter-spacing: -0.01em;
}
.side .subtitle {
  margin: 0 0 16px;
  font-size: 0.94rem;
  line-height: 1.5;
  color: var(--muted);
  word-break: break-word;
}
.side-list {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: side;
}
.side-list li + li { border-top: 1px solid var(--line); }
.slink {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 6px 0;
  font-size: 0.97rem;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.18s ease;
}
.slink::before {
  counter-increment: side;
  content: counter(side, decimal-leading-zero);
  font-family: var(--display);
  font-size: 0.76rem;
  color: var(--faint);
  min-width: 20px;
}
.slink:hover, .slink:focus-visible { transform: translateX(4px); }
.side-top {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 2px solid var(--ink);
  font-size: 0.94rem;
  font-weight: 700;
}
.side-top a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  text-decoration: none;
}

/* ---------- 页脚 ---------- */
.foot {
  margin-top: 60px;
  padding: 36px 22px 44px;
  border-top: 2px solid var(--ink);
  background: #fff;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  gap: 20px;
  align-items: start;
  max-width: 1180px;
  margin-left: auto;
  margin-right: auto;
}
.foot-brand a {
  font-family: var(--display);
  font-size: 1.35rem;
  letter-spacing: 0.02em;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  min-height: 40px;
}
.foot-nav {
  grid-column: span 2;
  display: flex;
  flex-wrap: wrap;
  gap: 0 16px;
}
.foot-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 4px 0;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  border-bottom: 2px solid transparent;
}
.foot-nav a:hover { border-bottom-color: var(--ink); }
.foot-copy {
  text-align: right;
  font-size: 0.9rem;
  color: var(--muted);
}
.foot-copy p { margin: 0; line-height: 40px; }

/* ---------- 动效 ---------- */
@media (prefers-reduced-motion: no-preference) {
  html.js .body-col > div {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.55s ease, transform 0.55s ease;
  }
  html.js .body-col > div.in {
    opacity: 1;
    transform: none;
  }
  .drawer[open] .drawer-list li { animation: rise 0.28s ease both; }
  .drawer[open] .drawer-list li:nth-child(2) { animation-delay: 0.03s; }
  .drawer[open] .drawer-list li:nth-child(3) { animation-delay: 0.06s; }
  .drawer[open] .drawer-list li:nth-child(4) { animation-delay: 0.09s; }
  .drawer[open] .drawer-list li:nth-child(5) { animation-delay: 0.12s; }
  .drawer[open] .drawer-list li:nth-child(6) { animation-delay: 0.15s; }
  .drawer[open] .drawer-list li:nth-child(7) { animation-delay: 0.18s; }
}
@keyframes rise {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .stage {
    grid-template-columns: minmax(0, 1fr);
    gap: 34px;
    padding-top: 24px;
  }
  .side { position: static; }
  .hero {
    grid-template-columns: minmax(0, 1fr);
    min-height: 0;
    gap: 26px;
    padding: 8px 0 34px;
  }
  .hero-copy { order: 1; }
  .hero-visual { order: 2; aspect-ratio: 16 / 11; }
  h1 { font-size: clamp(2.6rem, 11vw, 4.2rem); }
}

@media (max-width: 720px) {
  body { font-size: 16px; }
  .wrap { padding: 0 16px; }
  .top {
    grid-template-columns: auto minmax(0, 1fr);
    grid-template-areas:
      "menu brand"
      "find find";
    row-gap: 10px;
    padding: 12px 16px;
  }
  .drawer { grid-area: menu; }
  .brand { grid-area: brand; justify-self: end; }
  .find { grid-area: find; justify-self: stretch; }
  .find input { flex: 1 1 auto; width: auto; }
  .drawer-list { min-width: 0; width: min(280px, 82vw); }
  .body-col > div { padding: 26px 18px; border-radius: 14px; }
  .rlink { padding: 10px 13px; min-height: 46px; font-size: 16px; }
  .foot {
    grid-template-columns: 1fr 1fr;
    padding: 28px 16px 36px;
  }
  .foot-nav { grid-column: 1 / -1; order: 3; }
  .foot-copy { text-align: left; }
}

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