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

:root {
  color-scheme: dark;
  --bg: #000000;
  --panel: #121212;
  --ink: #e9edf4;
  --muted: #98a2b3;
  --line: #1d222a;
  --blue: #0d1728;
  --neon: #7be0ff;
  --gold: #efc978;
  --r: 28px;
}

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

html {
  background: #000000;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: #000000;
  color: var(--ink);
  font-family: 'IBM Plex Sans', system-ui, -apple-system, 'Segoe UI', 'Microsoft YaHei', sans-serif;
  font-size: 17px;
  font-weight: 400;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

p {
  margin: 0 0 1.1em;
}

a {
  color: inherit;
  text-decoration: none;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 3px;
  border-radius: 6px;
}

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

/* ---------- 顶部细条 ---------- */

.top {
  position: sticky;
  top: 0;
  z-index: 40;
  background: #000000;
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(6px);
}

.tape {
  background: var(--blue);
  border-bottom: 1px solid #16233a;
}

.tape p {
  margin: 0;
  max-width: 1240px;
  margin-inline: auto;
  padding: 7px 20px;
  font-size: 13px;
  font-weight: 300;
  line-height: 1.6;
  letter-spacing: 0.28em;
  color: #9fc7dd;
  text-align: center;
  text-shadow: 0 0 10px rgba(123, 224, 255, 0.35);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.bar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 12px;
  max-width: 1240px;
  margin-inline: auto;
  padding: 10px 20px;
}

.nav p {
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
  margin: 0;
}

.nav-l p {
  justify-content: flex-start;
}

.nav-r p {
  justify-content: flex-end;
}

.nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 10px 11px;
  font-size: 16px;
  font-weight: 400;
  color: #cbd3df;
  border-radius: 12px;
  transition: color 0.18s ease, background-color 0.18s ease;
}

.nav a:hover {
  color: #ffffff;
  background: var(--panel);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 6px 14px;
  font-size: 19px;
  font-weight: 600;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.glyph {
  width: 18px;
  height: 18px;
  border-radius: 7px;
  background: var(--neon);
  box-shadow: 0 0 12px rgba(123, 224, 255, 0.55);
  flex: none;
}

/* ---------- 首屏 ---------- */

.hero {
  position: relative;
  min-height: 70vh;
  display: grid;
  align-content: end;
  padding: 72px 24px 56px;
  background-color: #000000;
  background-image:
    radial-gradient(rgba(123, 224, 255, 0.16) 1px, transparent 1px),
    radial-gradient(1200px 420px at 78% 12%, rgba(13, 23, 40, 0.95), transparent 70%);
  background-size: 22px 22px, auto;
  border-bottom: 1px solid var(--line);
}

.hero-inner {
  width: 100%;
  max-width: 1160px;
  margin-inline: auto;
  text-align: right;
}

.chip {
  display: block;
  width: var(--r);
  height: var(--r);
  margin-left: auto;
  margin-bottom: 26px;
  border-radius: 12px;
  background: var(--neon);
  box-shadow: 0 0 22px rgba(123, 224, 255, 0.4);
}

.hero h1 {
  margin: 0;
  font-size: clamp(2.2rem, 8.5vw, 5.6rem);
  font-weight: 600;
  line-height: 1.04;
  letter-spacing: -0.025em;
  text-wrap: balance;
  text-shadow: 0 0 30px rgba(123, 224, 255, 0.12);
}

.lede {
  max-width: 52ch;
  margin: 24px 0 0 auto;
  font-size: 16px;
  font-weight: 300;
  line-height: 1.8;
  color: var(--muted);
  text-align: right;
}

/* ---------- 主体 ---------- */

.body {
  display: grid;
  grid-template-columns: 236px minmax(0, 1fr);
  gap: 56px;
  max-width: 1160px;
  margin-inline: auto;
  padding: 64px 24px 88px;
}

.body > article {
  grid-column: 2;
  padding: 44px 0 40px;
  border-top: 1px solid var(--line);
  scroll-margin-top: 132px;
}

.body > article:first-of-type {
  border-top: 0;
  padding-top: 0;
}

.rail {
  grid-column: 1;
  grid-row: 1;
  align-self: start;
  position: sticky;
  top: 132px;
}

.eyebrow {
  display: block;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.3em;
  color: var(--neon);
  margin-bottom: 6px;
}

.rail-title {
  margin: 0 0 18px;
  font-size: 22px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: #ffffff;
}

.rail-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: rail;
  border-left: 1px solid var(--line);
}

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

.rail-list a {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 42px;
  padding: 9px 12px;
  font-size: 15px;
  color: #a9b3c2;
  border-radius: 0 12px 12px 0;
  transition: color 0.16s ease, background-color 0.16s ease, transform 0.16s ease;
}

.rail-list a::before {
  content: counter(rail, decimal-leading-zero);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: #4d5a6d;
}

.rail-list a:hover {
  color: #ffffff;
  background: var(--panel);
  transform: translateX(2px);
}

.rail-list a:hover::before {
  color: var(--neon);
}

.body h2 {
  margin: 0 0 18px;
  font-size: clamp(1.45rem, 3.1vw, 2.05rem);
  font-weight: 600;
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: #ffffff;
}

.body h3 {
  margin: 30px 0 12px;
  font-size: 19px;
  font-weight: 500;
  color: #dbe3ee;
}

.body p,
.body li {
  color: #c6ceda;
  font-weight: 300;
  line-height: 1.85;
}

.body p,
.body ul,
.body ol {
  max-width: 68ch;
}

.body ul,
.body ol {
  padding-left: 22px;
  margin: 0 0 1.2em;
}

.body li {
  margin-bottom: 0.5em;
}

.body strong {
  color: #ffffff;
  font-weight: 500;
}

.body blockquote {
  margin: 26px 0;
  padding: 18px 22px;
  background: var(--panel);
  border-radius: var(--r);
  color: #dbe3ee;
}

.body blockquote p:last-child {
  margin-bottom: 0;
}

.body a {
  color: var(--neon);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.body figure {
  margin: 26px 0;
}

.body figcaption {
  margin-top: 8px;
  font-size: 14px;
  color: var(--muted);
}

/* 进入动效 */

.js .body > article {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.js .body > article.in {
  opacity: 1;
  transform: none;
}

/* ---------- 页脚 ---------- */

.foot {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: end;
  gap: 18px;
  max-width: 1160px;
  margin-inline: auto;
  padding: 48px 24px 56px;
  border-top: 1px solid var(--line);
}

.wordmark {
  grid-column: 1;
  margin: 0;
  font-size: clamp(2rem, 8vw, 4.4rem);
  font-weight: 600;
  line-height: 0.95;
  letter-spacing: -0.03em;
  color: #ffffff;
  text-shadow: 0 0 26px rgba(123, 224, 255, 0.18);
}

.copy {
  grid-column: 2;
  align-self: end;
  font-size: 12px;
  font-weight: 300;
  letter-spacing: 0.18em;
  color: #5f6b7d;
  padding-bottom: 6px;
  text-align: center;
}

.back {
  grid-column: 3;
  margin: 0;
  text-align: right;
}

.back a {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 9px 16px;
  font-size: 15px;
  color: #cbd3df;
  background: var(--panel);
  border-radius: 999px;
  transition: color 0.18s ease, background-color 0.18s ease;
}

.back a:hover {
  color: #000000;
  background: var(--neon);
}

/* ---------- 移动端 ---------- */

@media (max-width: 860px) {
  .bar {
    grid-template-columns: 1fr;
    gap: 6px;
    padding: 10px 16px 12px;
  }

  .brand {
    order: -1;
    justify-content: flex-start;
    padding-left: 2px;
  }

  .nav-l p,
  .nav-r p {
    justify-content: flex-start;
  }

  .nav a {
    padding: 9px 10px;
    font-size: 16px;
    background: var(--panel);
  }

  .hero {
    min-height: 62vh;
    padding: 48px 18px 40px;
    background-size: 18px 18px, auto;
  }

  .hero h1 {
    font-size: clamp(2rem, 10.5vw, 3.2rem);
    text-align: right;
  }

  .lede {
    text-align: right;
    font-size: 15px;
  }

  .body {
    grid-template-columns: 1fr;
    gap: 26px;
    padding: 40px 18px 56px;
  }

  .rail {
    position: static;
    grid-column: 1;
    grid-row: auto;
    padding-bottom: 22px;
    border-bottom: 1px solid var(--line);
  }

  .rail-list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    border-left: 0;
    gap: 4px;
  }

  .rail-list a {
    background: var(--panel);
    border-radius: 12px;
    min-height: 44px;
  }

  .body > article {
    grid-column: 1;
    padding: 32px 0 28px;
    scroll-margin-top: 190px;
  }

  .foot {
    grid-template-columns: 1fr;
    align-items: start;
    gap: 12px;
    padding: 36px 18px 44px;
  }

  .wordmark,
  .copy,
  .back {
    grid-column: 1;
    text-align: left;
  }

  .copy {
    padding-bottom: 0;
    letter-spacing: 0.12em;
  }

  .back a {
    background: var(--panel);
  }
}

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

  .js .body > article {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

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