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

:root {
  --ink: #1f1f1f;
  --paper: #ffffff;
  --mist: #f5f5f5;
  --line: #e2e2e2;
  --dim: #6b6b6b;
  --soft: #0b0b0b;
  --r-lg: 24px;
  --r-md: 16px;
  --shadow: 0 4px 6px rgba(0, 0, 0, .05), 0 12px 28px rgba(0, 0, 0, .04);
  --font: 'Outfit', 'Rubik', system-ui, -apple-system, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--mist);
  color: var(--ink);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.72;
  overflow-x: hidden;
}

img { max-width: 100%; }

a { color: inherit; }

:focus-visible {
  outline: 2px solid currentColor;
  outline-offset: 3px;
}

/* ---------- 顶部 ---------- */
.masthead {
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.mast-top {
  max-width: 1180px;
  margin: 0 auto;
  padding: 12px 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -.02em;
  text-decoration: none;
  color: var(--ink);
}

.brand img {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  object-fit: cover;
  border: 1px solid var(--line);
}

.mast-nav {
  position: sticky;
  top: 0;
  z-index: 30;
  background: rgba(255, 255, 255, .93);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.chips {
  max-width: 1180px;
  margin: 0 auto;
  padding: 8px 20px;
  list-style: none;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.chips::-webkit-scrollbar { display: none; }

.chips a {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid var(--ink);
  border-radius: 999px;
  background: var(--paper);
  color: var(--ink);
  font-size: 16px;
  font-weight: 500;
  white-space: nowrap;
  text-decoration: none;
  transition: background .18s ease, color .18s ease, transform .18s ease;
}

.chips a:hover { transform: scale(1.03); }

.chips a.on {
  background: var(--ink);
  color: #fff;
}

/* ---------- 头图 ---------- */
.hero {
  position: relative;
  min-height: 45vh;
  display: grid;
  place-items: center;
  padding: 44px 20px 60px;
  text-align: center;
  color: #fff;
  overflow: hidden;
  border-radius: 0 0 44px 44px;
  background: linear-gradient(150deg, #1f1f1f 0%, #333 55%, #1f1f1f 100%);
}

.hero-media {
  position: absolute;
  inset: -12% 0 -8%;
  z-index: 0;
}

.hero-media--empty {
  background:
    radial-gradient(600px 220px at 20% 25%, rgba(255, 255, 255, .16), transparent 70%),
    radial-gradient(500px 260px at 85% 80%, rgba(255, 255, 255, .1), transparent 70%);
}

.hero-img {
  width: 100%;
  height: 120%;
  object-fit: cover;
  opacity: .5;
  transform: scale(1.08);
  will-change: transform;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 720px;
}

.hero-mark {
  margin: 0 0 10px;
  font-size: 16px;
  letter-spacing: .3em;
  text-transform: uppercase;
  color: #d8d8d8;
}

.hero h1 {
  margin: 0;
  font-size: clamp(28px, 7vw, 54px);
  line-height: 1.18;
  letter-spacing: -.025em;
  font-weight: 700;
  text-wrap: balance;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  margin-top: 22px;
  padding: 0 22px;
  border-radius: 999px;
  background: #fff;
  color: var(--ink);
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  transition: transform .18s ease, background .18s ease;
}

.hero-cta:hover { transform: scale(1.04); background: var(--mist); }

.band {
  height: 14px;
  background: linear-gradient(90deg, #1f1f1f 0 46%, #cfcfcf 46% 58%, #1f1f1f 58% 100%);
}

/* ---------- 主区 ---------- */
.wrap {
  max-width: 1180px;
  margin: 0 auto;
  padding: 26px 20px 60px;
  display: grid;
  gap: 18px;
}

.rail {
  display: grid;
  gap: 14px;
  align-content: start;
}

.rail-tile {
  background: var(--paper);
  border-radius: var(--r-md);
  padding: 16px 18px;
  box-shadow: var(--shadow);
  transition: transform .2s ease;
}

.rail-tile:hover { transform: scale(1.02); }

.rail-tile small {
  display: block;
  font-size: 16px;
  letter-spacing: .22em;
  color: var(--dim);
}

.rail-tile h2 {
  margin: 2px 0 12px;
  font-size: 22px;
  letter-spacing: -.01em;
}

.rail-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 2px;
}

.rail-list a {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 40px;
  padding: 6px 0;
  font-size: 16px;
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
}

.rail-list li:last-child a { border-bottom: 0; }

.rail-list b {
  font-size: 16px;
  font-weight: 600;
  color: var(--dim);
  letter-spacing: .04em;
  min-width: 2ch;
}

.rail-list a:hover span { text-decoration: underline; text-underline-offset: 4px; }

.rail-tile--ink {
  background: var(--ink);
  color: #fff;
}

.rail-brand {
  margin: 0 0 10px;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -.01em;
}

.rail-top {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  font-size: 16px;
  color: #e8e8e8;
  text-decoration: none;
  border-bottom: 1px solid #565656;
}

.sheet { min-width: 0; }

.prose {
  display: grid;
  gap: 16px;
}

.prose > div {
  background: var(--paper);
  border-bottom: 3px solid var(--ink);
  box-shadow: var(--shadow);
  padding: 26px 20px 24px;
  scroll-margin-top: 108px;
  transition: transform .2s ease, box-shadow .2s ease;
}

.prose > div:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 18px rgba(0, 0, 0, .09);
}

.prose > div:nth-child(even) { background: #fafafa; }

.prose > div:first-child {
  border-radius: var(--r-lg);
  overflow: hidden;
  padding-top: 30px;
}

.prose small {
  display: block;
  font-size: 16px;
  letter-spacing: .22em;
  color: var(--dim);
  margin-bottom: 2px;
}

.prose h2 {
  margin: 0 0 12px;
  font-size: clamp(22px, 4vw, 30px);
  line-height: 1.28;
  letter-spacing: -.02em;
}

.prose h3 {
  margin: 22px 0 8px;
  font-size: 19px;
  line-height: 1.4;
}

.prose p,
.prose li {
  margin: 0 0 14px;
  max-width: 68ch;
}

.prose p:last-child,
.prose li:last-child { margin-bottom: 0; }

.prose ul,
.prose ol {
  margin: 0 0 16px;
  padding-left: 22px;
}

.prose li { margin-bottom: 8px; }

.prose a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

.prose a:hover { background: #ececec; }

.prose blockquote {
  margin: 18px 0;
  padding: 14px 18px;
  border-left: 4px solid var(--ink);
  background: var(--mist);
  font-size: 16px;
}

.prose blockquote p { margin: 0; }

.prose img {
  display: block;
  width: 100%;
  height: auto;
  margin: 18px 0;
  border-radius: var(--r-md);
}

.prose strong { font-weight: 600; }

.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 16px;
}

.prose th,
.prose td {
  border-bottom: 1px solid var(--line);
  padding: 10px 8px;
  text-align: left;
}

/* ---------- 页脚 ---------- */
.foot {
  background: var(--ink);
  color: #fff;
  padding: 36px 20px 26px;
  border-radius: 44px 44px 0 0;
}

.cta {
  max-width: 1180px;
  margin: 0 auto 30px;
  padding: 22px 22px;
  border: 1px solid #434343;
  border-radius: var(--r-lg);
}

.cta-link {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-height: 44px;
  font-size: clamp(20px, 4.4vw, 30px);
  font-weight: 700;
  letter-spacing: -.02em;
  text-decoration: none;
  color: #fff;
}

.cta-link em {
  font-style: normal;
  font-size: 16px;
  font-weight: 500;
  color: #b8b8b8;
  border-bottom: 1px solid #565656;
  padding-bottom: 2px;
}

.foot-grid {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  gap: 22px;
}

.foot dl { margin: 0; }

.foot dt {
  font-size: 16px;
  letter-spacing: .18em;
  color: #a8a8a8;
  margin-bottom: 6px;
}

.foot dd {
  margin: 0;
}

.foot dd a {
  display: inline-block;
  min-height: 40px;
  padding: 8px 0;
  font-size: 16px;
  color: #ececec;
  text-decoration: none;
}

.foot dd a:hover { color: #fff; text-decoration: underline; text-underline-offset: 4px; }

.copy {
  max-width: 1180px;
  margin: 26px auto 0;
  padding-top: 14px;
  border-top: 1px solid #3a3a3a;
  font-size: 16px;
  color: #a8a8a8;
}

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .foot-grid { grid-template-columns: repeat(3, 1fr); }
  .cta { padding: 28px 30px; }
}

@media (min-width: 940px) {
  .wrap {
    grid-template-columns: 262px minmax(0, 1fr);
    gap: 24px;
    padding-top: 34px;
  }

  .rail { position: sticky; top: 82px; }

  .hero { border-radius: 0 0 64px 64px; }
}

@media (min-width: 1180px) {
  .prose > div { padding: 34px 30px 30px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .prose > div:hover,
  .chips a:hover,
  .hero-cta:hover,
  .rail-tile:hover { transform: none; }
  .hero-img { transform: none !important; }
}

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