/* ============================================================
   365平台登录 · 共享站点样式 /assets/site.css
   夜航灯带 + 档案索引：深墨蓝长卷、竖排轨道、唯一暖橙入口
   ============================================================ */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body { margin: 0; }

h1, h2, h3, h4, p, figure, blockquote, ul, ol, dl, dd { margin: 0; }
ul, ol { padding: 0; }
img, svg, video { display: block; max-width: 100%; height: auto; }
button, input, select, textarea { font: inherit; color: inherit; }
a { color: inherit; }

/* ---------- 2. Tokens ---------- */
:root {
  --ink-950: #061525;
  --ink-900: #0A2033;
  --ink-800: #12314A;
  --fog-100: #EAF4F8;
  --mist-300: #A9C0CC;
  --cyan-400: #39F2D4;
  --orange-500: #FF8A3D;
  --orange-600: #E96D1F;
  --slate-700: #27465C;

  --glass: rgba(255, 255, 255, .08);
  --line: rgba(57, 242, 212, .16);
  --line-soft: rgba(234, 244, 248, .10);

  --rail-w: 96px;
  --bar-h: 64px;
  --shell: 1280px;
  --pad: clamp(20px, 5vw, 72px);
  --radius: 18px;
  --radius-sm: 12px;
  --ease: cubic-bezier(.2, .8, .2, 1);

  --font-head: "Barlow Condensed", "Oswald", "Noto Sans SC", "PingFang SC", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", SFMono-Regular, Consolas, monospace;
}

/* ---------- 3. 基础排版（中文优先） ---------- */
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.78;
  color: var(--fog-100);
  background-color: var(--ink-950);
  background-image:
    radial-gradient(900px 520px at 88% -10%, rgba(18, 49, 74, .9), transparent 70%),
    radial-gradient(720px 440px at 2% 6%, rgba(57, 242, 212, .07), transparent 66%),
    linear-gradient(180deg, #061525 0%, #05121f 100%);
  -webkit-font-smoothing: antialiased;
}

p, li { letter-spacing: .01em; }

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: .005em;
  color: var(--fog-100);
  text-wrap: balance;
}

p { text-wrap: pretty; }

::selection { background: rgba(57, 242, 212, .28); color: #fff; }

:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 3px;
  border-radius: 4px;
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .02em;
}

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

[id] { scroll-margin-top: 90px; }

/* ---------- 4. Skip link ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  transform: translateY(-180%);
  padding: 10px 18px;
  border-radius: 10px;
  background: var(--cyan-400);
  color: var(--ink-950);
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .06em;
  text-decoration: none;
  transition: transform .18s var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 5. 侧边轨道头部 ---------- */
.rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--rail-w);
  z-index: 80;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 14px 8px 12px;
  background: linear-gradient(180deg, rgba(10, 32, 51, .97), rgba(5, 16, 28, .99));
  border-right: 1px solid var(--line-soft);
}

.rail::after {
  content: "";
  position: absolute;
  top: 0; bottom: 0; right: -1px;
  width: 1px;
  background: linear-gradient(180deg, transparent, rgba(57, 242, 212, .45) 22%, rgba(57, 242, 212, .08) 68%, transparent);
  pointer-events: none;
}

.rail__bar {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

/* 品牌 */
.brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--fog-100);
}

.brand__mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .01em;
  color: #04211c;
  background: linear-gradient(150deg, var(--cyan-400), #1cbfa8);
  box-shadow: 0 0 0 1px rgba(57, 242, 212, .35), 0 10px 26px -14px rgba(57, 242, 212, .85);
}

.brand__text {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  min-width: 0;
}

.brand__name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 12.5px;
  line-height: 1.25;
  letter-spacing: .04em;
  text-align: center;
  padding-bottom: 2px;
  border-bottom: 1px solid rgba(57, 242, 212, .35);
}

.brand__sub { display: none; }

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 15px;
  border-radius: 999px;
  border: 1px solid var(--slate-700);
  background: var(--glass);
  color: var(--fog-100);
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: .1em;
  cursor: pointer;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}
.nav-toggle:hover { border-color: var(--cyan-400); color: var(--cyan-400); }

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  width: 16px;
}
.nav-toggle__bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform .2s var(--ease), opacity .2s var(--ease);
}
.rail[data-open="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.rail[data-open="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.rail[data-open="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

/* 导航 */
.rail__nav {
  display: flex;
  flex-direction: column;
  flex: 1 1 auto;
  min-height: 0;
  gap: 10px;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  scrollbar-color: var(--slate-700) transparent;
}

.rail__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.rail__link {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
  padding: 10px 6px;
  border-radius: var(--radius-sm);
  color: var(--mist-300);
  text-decoration: none;
  transition: color .18s var(--ease), background-color .18s var(--ease);
}

.rail__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 3px;
  height: 0;
  border-radius: 2px;
  background: var(--cyan-400);
  transform: translateY(-50%);
  opacity: 0;
  transition: height .2s var(--ease), opacity .2s var(--ease);
}

.rail__link:hover {
  color: var(--fog-100);
  background-color: rgba(255, 255, 255, .04);
}
.rail__link:hover::before { height: 20px; opacity: .55; }

.rail__link[aria-current="page"] {
  color: var(--cyan-400);
  background-color: rgba(57, 242, 212, .09);
}
.rail__link[aria-current="page"]::before { height: 24px; opacity: 1; }

.rail__num {
  font-family: var(--font-mono);
  font-size: 10px;
  line-height: 1;
  letter-spacing: .1em;
  color: rgba(169, 192, 204, .62);
}
.rail__link[aria-current="page"] .rail__num { color: var(--cyan-400); }

.rail__label {
  writing-mode: vertical-rl;
  text-orientation: upright;
  font-size: 12px;
  font-weight: 500;
  line-height: 1;
  letter-spacing: .16em;
}

.rail__foot {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding-top: 12px;
  border-top: 1px solid var(--line-soft);
}

.rail__cta {
  width: 100%;
  padding: 11px 4px;
  border-radius: var(--radius-sm);
  font-size: 12.5px;
  letter-spacing: .08em;
}

.rail__note {
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: .08em;
  color: rgba(169, 192, 204, .78);
  text-align: center;
}

/* 遮罩 */
.rail__scrim { display: none; }

/* 阅读进度 */
.rail__progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 90;
  background: rgba(234, 244, 248, .07);
  pointer-events: none;
}
.rail__progress-bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan-400), rgba(57, 242, 212, .18));
  transition: width .1s linear;
}

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5em;
  padding: 13px 24px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .06em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .18s var(--ease), border-color .18s var(--ease), color .18s var(--ease), transform .18s var(--ease);
}

.btn--login {
  background: var(--orange-500);
  color: #101d29;
  box-shadow: 0 0 0 1px rgba(255, 138, 61, .35), 0 14px 30px -20px rgba(255, 138, 61, .95);
}
.btn--login:hover { background: var(--orange-600); transform: translateY(-1px); }
.btn--login:active { transform: translateY(0); }

.btn--ghost {
  background: var(--glass);
  border-color: var(--slate-700);
  color: var(--fog-100);
}
.btn--ghost:hover { border-color: var(--cyan-400); color: var(--cyan-400); }

.btn--quiet {
  padding: 0;
  border: 0;
  background: none;
  color: var(--cyan-400);
}
.btn--quiet:hover { color: var(--fog-100); }

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: .4em;
  color: var(--cyan-400);
  font-weight: 500;
  text-decoration: none;
  border-bottom: 1px solid rgba(57, 242, 212, .35);
  padding-bottom: 1px;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}
.link-arrow::after { content: "→"; font-family: var(--font-mono); font-size: .9em; }
.link-arrow:hover { border-color: var(--cyan-400); color: var(--fog-100); }

/* ---------- 7. 容器 / 章节 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--pad);
}

.section {
  position: relative;
  padding-block: clamp(46px, 7vw, 96px);
}
.section--alt {
  background:
    linear-gradient(180deg, rgba(18, 49, 74, .55), rgba(10, 32, 51, .18) 70%, transparent),
    linear-gradient(180deg, transparent, rgba(57, 242, 212, .04));
  border-block: 1px solid var(--line-soft);
}
.section--deep {
  background: linear-gradient(180deg, rgba(4, 13, 23, .9), rgba(6, 21, 37, .4));
  border-top: 1px solid var(--line);
}

.section__head { display: flex; flex-direction: column; gap: 14px; max-width: 62ch; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--cyan-400);
  text-transform: uppercase;
}
.eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: currentColor;
  opacity: .7;
}

.section__title {
  font-size: clamp(30px, 4vw, 54px);
  letter-spacing: .01em;
}

.lede {
  font-size: clamp(15px, 1.4vw, 17.5px);
  line-height: 1.85;
  color: var(--mist-300);
  max-width: 42em;
}

/* ---------- 8. 网格 ---------- */
.grid { display: grid; gap: clamp(18px, 3vw, 34px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--split { grid-template-columns: 1.15fr .85fr; align-items: start; }

.stack { display: flex; flex-direction: column; gap: clamp(14px, 2vw, 22px); }

/* ---------- 9. 卡片 / 标签 ---------- */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 30px);
  border-radius: var(--radius);
  border: 1px solid var(--line-soft);
  background: var(--ink-800);
  transition: border-color .2s var(--ease), transform .2s var(--ease);
}
.card:hover { border-color: rgba(57, 242, 212, .34); }

.card--glass {
  background: var(--glass);
  border-color: var(--line);
  backdrop-filter: blur(16px) saturate(120%);
  -webkit-backdrop-filter: blur(16px) saturate(120%);
  box-shadow: 0 24px 60px -40px rgba(0, 0, 0, .9);
}

.card--solid {
  background: linear-gradient(160deg, var(--ink-800), #0d2739);
  border-color: rgba(234, 244, 248, .07);
}

.card__title {
  font-family: var(--font-head);
  font-size: clamp(19px, 1.8vw, 24px);
  font-weight: 700;
  letter-spacing: .02em;
  margin-bottom: 8px;
}

.card__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mist-300);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: .45em;
  padding: 4px 11px;
  border-radius: 999px;
  border: 1px solid var(--slate-700);
  background: rgba(255, 255, 255, .03);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--mist-300);
  white-space: nowrap;
}
.tag--cyan {
  border-color: rgba(57, 242, 212, .42);
  color: var(--cyan-400);
  background: rgba(57, 242, 212, .08);
}

/* ---------- 10. 面包屑 ---------- */
.crumbs {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: rgba(169, 192, 204, .8);
  padding-block: 22px 0;
}
.crumbs li { display: inline-flex; align-items: center; gap: 8px; }
.crumbs li + li::before { content: "/"; color: var(--slate-700); }
.crumbs a { color: var(--mist-300); text-decoration: none; transition: color .16s var(--ease); }
.crumbs a:hover { color: var(--cyan-400); }
.crumbs [aria-current="page"] { color: var(--fog-100); }

/* ---------- 11. 图像容器（页面阶段放图占位） ---------- */
.media {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--line-soft);
  background:
    radial-gradient(120% 90% at 78% 8%, rgba(57, 242, 212, .16), transparent 58%),
    linear-gradient(150deg, #0d2a40 0%, #061525 58%, #0a2033 100%);
}
.media img,
.media svg,
.media video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(200deg, rgba(57, 242, 212, .12), transparent 46%, rgba(6, 21, 37, .62));
  pointer-events: none;
}
.media--wide { aspect-ratio: 16 / 9; }
.media--screen { aspect-ratio: 16 / 10; }
.media--square { aspect-ratio: 1 / 1; }
.media--tall { aspect-ratio: 4 / 5; }
.media--duo {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
  aspect-ratio: 16 / 9;
  border-color: var(--line);
}
.media--duo > * { min-width: 0; height: 100%; }
.media__cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: rgba(169, 192, 204, .82);
}

/* ---------- 12. 档案列表 / 提示 ---------- */
.data-list {
  display: grid;
  gap: 0;
  margin: 0;
  border-top: 1px solid var(--line-soft);
}
.data-list > div,
.data-list dt { min-width: 0; }
.data-list dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--mist-300);
  padding: 13px 0 4px;
}
.data-list dd {
  margin: 0;
  padding-bottom: 13px;
  border-bottom: 1px solid var(--line-soft);
  font-size: 15.5px;
  color: var(--fog-100);
}

.notice {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(57, 242, 212, .28);
  border-left-width: 3px;
  background: rgba(57, 242, 212, .06);
  font-size: 14.5px;
  color: var(--mist-300);
}
.notice__title {
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--fog-100);
}

/* ---------- 13. 页脚 ---------- */
.foot {
  position: relative;
  margin-top: clamp(48px, 8vw, 108px);
  overflow: hidden;
  color: var(--mist-300);
  background: linear-gradient(180deg, rgba(10, 32, 51, .92), #04101c 82%);
  border-top: 1px solid var(--line);
}
.foot::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(680px 240px at 10% 0%, rgba(57, 242, 212, .1), transparent 72%);
}

.foot__inner {
  position: relative;
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(34px, 5vw, 60px) var(--pad) clamp(20px, 3vw, 30px);
  display: grid;
  grid-template-columns: 1.4fr 1fr 1.15fr 1fr;
  gap: clamp(26px, 4vw, 46px);
}

.foot__lead { display: flex; flex-direction: column; gap: 10px; }

.foot__wordmark {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(54px, 8vw, 96px);
  line-height: .84;
  letter-spacing: -.02em;
  color: transparent;
  -webkit-text-stroke: 1px rgba(57, 242, 212, .38);
  margin-bottom: 2px;
}

.foot__brand {
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--fog-100);
}

.foot__line { font-size: 14.5px; line-height: 1.7; color: var(--mist-300); }

.foot__tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 6px;
}

.foot__col { display: flex; flex-direction: column; gap: 12px; min-width: 0; }

.foot__title {
  display: flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: .2em;
  color: var(--mist-300);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line-soft);
}
.foot__title::before {
  content: "";
  width: 14px;
  height: 2px;
  background: var(--cyan-400);
}

.foot__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 9px;
  font-size: 14.5px;
}
.foot__list > li > a {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: var(--fog-100);
  text-decoration: none;
  transition: color .18s var(--ease);
}
.foot__list > li > a::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--slate-700);
  transition: background-color .18s var(--ease), box-shadow .18s var(--ease);
}
.foot__list > li > a:hover { color: var(--cyan-400); }
.foot__list > li > a:hover::before {
  background: var(--cyan-400);
  box-shadow: 0 0 0 3px rgba(57, 242, 212, .14);
}

.foot__list--contact { gap: 0; }

.foot__contact {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 4px 10px;
  padding: 10px 0;
  border-bottom: 1px dashed rgba(234, 244, 248, .1);
}
.foot__contact--block { grid-template-columns: minmax(0, 1fr); }

.foot__k {
  grid-column: 1 / -1;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .14em;
  color: rgba(169, 192, 204, .82);
}
.foot__v {
  font-size: 14.5px;
  color: var(--fog-100);
  overflow-wrap: anywhere;
}

.copy {
  padding: 5px 11px;
  border-radius: 999px;
  border: 1px solid var(--slate-700);
  background: transparent;
  color: var(--mist-300);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  cursor: pointer;
  transition: border-color .18s var(--ease), color .18s var(--ease), background-color .18s var(--ease);
}
.copy:hover { border-color: var(--cyan-400); color: var(--cyan-400); }
.copy[data-copied="true"] {
  border-color: var(--cyan-400);
  color: var(--ink-950);
  background: var(--cyan-400);
}

.foot__note {
  font-size: 12.5px;
  line-height: 1.7;
  color: rgba(169, 192, 204, .82);
}

.foot__status {
  min-height: 1.4em;
  font-size: 11.5px;
  letter-spacing: .04em;
  color: var(--cyan-400);
}

.foot__base {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 26px;
  margin-top: 6px;
  padding-top: 20px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: rgba(169, 192, 204, .76);
}
.foot__meta { margin: 0; }

.foot__legal {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}
.foot__legal a {
  color: var(--mist-300);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}
.foot__legal a:hover { color: var(--cyan-400); border-color: var(--cyan-400); }

/* ---------- 14. 显现动效 ---------- */
.reveal-ready [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .55s var(--ease), transform .55s var(--ease);
}
.reveal-ready [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 15. 桌面偏移 ---------- */
@media (min-width: 1024px) {
  body { padding-left: var(--rail-w); }
}

/* ---------- 16. 平板 / 手机 ---------- */
@media (max-width: 1023px) {
  body {
    padding-top: var(--bar-h);
    padding-left: 0;
  }

  .rail {
    top: 0;
    left: 0;
    right: 0;
    bottom: auto;
    width: 100%;
    height: var(--bar-h);
    flex-direction: row;
    align-items: center;
    padding: 0 14px;
    border-right: 0;
    border-bottom: 1px solid var(--line-soft);
    background: linear-gradient(180deg, rgba(10, 32, 51, .98), rgba(6, 21, 37, .99));
  }
  .rail::after { display: none; }

  .rail__bar {
    flex-direction: row;
    flex: 1 1 auto;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    width: 100%;
    min-width: 0;
  }

  .brand {
    flex-direction: row;
    align-items: center;
    gap: 10px;
    min-width: 0;
  }
  .brand__mark { width: 32px; height: 32px; font-size: 11px; border-radius: 10px; }
  .brand__text { align-items: flex-start; }
  .brand__name {
    font-size: 15.5px;
    text-align: left;
    border-bottom: 1px solid rgba(57, 242, 212, .3);
    white-space: nowrap;
  }
  .brand__sub {
    display: block;
    font-family: var(--font-mono);
    font-size: 9.5px;
    letter-spacing: .16em;
    color: var(--mist-300);
    text-transform: uppercase;
  }

  .nav-toggle { display: inline-flex; flex: 0 0 auto; }

  .rail__nav {
    position: fixed;
    top: var(--bar-h);
    left: 0;
    bottom: 0;
    width: min(336px, 86vw);
    z-index: 75;
    padding: 18px 16px 26px;
    gap: 14px;
    background: linear-gradient(180deg, #0A2033, #061525 72%);
    border-right: 1px solid var(--line);
    box-shadow: 24px 0 60px -40px #000;
    transform: translateX(-104%);
    transition: transform .26s var(--ease);
    overflow-y: auto;
  }
  .rail[data-open="true"] .rail__nav { transform: none; }

  .rail__list { flex: 0 0 auto; gap: 4px; }

  .rail__link {
    flex-direction: row;
    align-items: center;
    justify-content: flex-start;
    gap: 12px;
    padding: 13px 14px;
  }
  .rail__link::before {
    left: 0;
    top: 9px;
    bottom: 9px;
    width: 3px;
    height: auto;
    transform: none;
  }
  .rail__link:hover::before,
  .rail__link[aria-current="page"]::before { height: auto; }

  .rail__num { font-size: 11px; letter-spacing: .12em; }
  .rail__label {
    writing-mode: horizontal-tb;
    text-orientation: mixed;
    font-size: 15.5px;
    font-weight: 600;
    letter-spacing: .08em;
  }

  .rail__foot {
    margin-top: auto;
    align-items: stretch;
    gap: 10px;
    padding-top: 16px;
  }
  .rail__cta { width: 100%; padding: 13px 10px; font-size: 15px; border-radius: 999px; }
  .rail__note { text-align: left; font-size: 10.5px; }

  .rail__scrim {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 70;
    border: 0;
    background: rgba(3, 12, 22, .7);
    backdrop-filter: blur(3px);
    -webkit-backdrop-filter: blur(3px);
    opacity: 0;
    pointer-events: none;
    transition: opacity .24s var(--ease);
  }
  .rail[data-open="true"] .rail__scrim { opacity: 1; pointer-events: auto; }

  html.is-nav-open,
  html.is-nav-open body { overflow: hidden; }

  .rail__progress { top: 0; }
}

@media (max-width: 900px) {
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--split { grid-template-columns: minmax(0, 1fr); }
  .foot__inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .foot__lead { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  body { font-size: 15.5px; }
  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }
  .foot__inner { grid-template-columns: minmax(0, 1fr); }
  .foot__base { font-size: 11.5px; }
  .foot__wordmark { font-size: clamp(48px, 22vw, 76px); }
  .media--duo { aspect-ratio: 4 / 3; }
}

/* ---------- 17. 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
  .reveal-ready [data-reveal] { opacity: 1; transform: none; }
  .rail__nav { transition: none; }
  .rail__progress-bar { transition: none; }
}