/* =========================================================
   博业看台 · 共享 Site Kit  /assets/site.css
   看台剖面 · 玻璃与纸白并置
   ========================================================= */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--bar-h, 62px) + 18px);
  background: #061020;
}

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd,
ul, ol { margin: 0; }

ul, ol { padding: 0; list-style: none; }

img, svg, video, canvas { display: block; max-width: 100%; }

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

input, textarea, select { font: inherit; }

table { border-collapse: collapse; width: 100%; }

/* ---------- 2. Tokens ---------- */
:root {
  --c-sky: #0A1A2F;
  --c-lake-deep: #0E5F86;
  --c-lake: #1F8FBF;
  --c-lake-mist: #A8D6E8;
  --c-dusk: #4B3B7A;
  --c-dusk-light: #9A8ACB;
  --c-grass: #2F9E5B;
  --c-hoop: #F0872E;
  --c-data: #7FE3D4;
  --c-paper: #F5F8FA;
  --c-slate: #6B7A8C;
  --c-ink: #061020;

  --tx-1: #EDF4FA;
  --tx-2: #B4C6D6;
  --tx-3: #7F92A4;
  --paper-tx-1: #0A1A2F;
  --paper-tx-2: #55677A;

  --line: rgba(168, 214, 232, 0.16);
  --line-strong: rgba(168, 214, 232, 0.34);

  --font-display: "Barlow Condensed", "Oswald", "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;

  --rail-w: 84px;
  --bar-h: 62px;
  --gutter: clamp(20px, 4vw, 56px);
  --radius: 10px;
  --radius-lg: 16px;
  --shadow-card: 0 24px 48px -30px rgba(6, 16, 32, 1);
  --ease: cubic-bezier(.2, .6, .3, 1);
  --dur: 200ms;
}

/* ---------- 3. 基础排版 ---------- */
body {
  position: relative;
  min-height: 100vh;
  overflow-x: hidden;
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  color: var(--tx-1);
  background-color: var(--c-sky);
  background-image:
    radial-gradient(1100px 620px at 84% -12%, rgba(75, 59, 122, 0.55), transparent 62%),
    radial-gradient(900px 520px at 6% 108%, rgba(31, 143, 191, 0.22), transparent 64%),
    linear-gradient(180deg, #0A1A2F 0%, #08152A 58%, #061020 100%);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(168, 214, 232, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(168, 214, 232, 0.05) 1px, transparent 1px);
  background-size: 88px 88px;
  -webkit-mask-image: radial-gradient(130% 88% at 52% 0%, #000 18%, transparent 76%);
  mask-image: radial-gradient(130% 88% at 52% 0%, #000 18%, transparent 76%);
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: 0;
  text-wrap: balance;
}

p { word-break: break-word; }

strong { color: #fff; font-weight: 700; }

::selection {
  background: rgba(31, 143, 191, 0.45);
  color: #fff;
}

:focus-visible {
  outline: 2px solid var(--c-lake);
  outline-offset: 2px;
  border-radius: 4px;
}

html[data-nav-open] { overflow: hidden; }

/* ---------- 4. 版面容器与网格 ---------- */
#main-content {
  position: relative;
  z-index: 1;
  margin-left: var(--rail-w);
  padding-top: var(--bar-h);
  min-height: 60vh;
}

.container {
  width: 100%;
  max-width: 1280px;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(44px, 6.5vw, 92px); }

.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 14px 32px;
  margin-bottom: clamp(24px, 3vw, 40px);
}

.section__title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.125rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.01em;
  color: var(--tx-1);
}

.section__lead {
  max-width: 56ch;
  font-size: 16px;
  line-height: 1.75;
  color: var(--tx-2);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--grid-gap, 24px);
}

.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.05em;
  white-space: nowrap;
  transition:
    transform var(--dur) var(--ease),
    background-color var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.btn--primary {
  background: linear-gradient(120deg, var(--c-lake) 0%, var(--c-lake-deep) 100%);
  color: #FFFFFF;
  box-shadow:
    inset 0 0 0 1px rgba(168, 214, 232, 0.3),
    0 12px 28px -16px rgba(31, 143, 191, 1);
}

.btn--primary:hover {
  transform: translateY(-4px);
  box-shadow:
    inset 0 0 0 1px rgba(168, 214, 232, 0.55),
    0 22px 38px -18px rgba(31, 143, 191, 1);
}

.btn--ghost {
  background: rgba(14, 95, 134, 0.14);
  border-color: var(--line-strong);
  color: var(--tx-2);
}

.btn--ghost:hover {
  transform: translateY(-4px);
  color: #FFFFFF;
  border-color: var(--c-dusk-light);
  background: rgba(75, 59, 122, 0.3);
}

.btn--hoop {
  background: rgba(240, 135, 46, 0.16);
  border-color: rgba(240, 135, 46, 0.55);
  color: #FFC695;
}

.btn--hoop:hover {
  transform: translateY(-4px);
  background: rgba(240, 135, 46, 0.3);
  color: #FFE0C4;
}

/* ---------- 6. 展签与标签 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--c-lake-mist);
}

.eyebrow::before {
  content: "";
  width: 20px;
  height: 1px;
  background: currentColor;
  opacity: 0.72;
}

.eyebrow--hoop { color: var(--c-hoop); }
.eyebrow--grass { color: var(--c-grass); }
.eyebrow--data { color: var(--c-data); }

.data {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.05em;
  font-variant-numeric: tabular-nums;
  color: var(--c-data);
}

.data--muted { color: var(--tx-3); }

/* ---------- 7. 玻璃层 / 纸白层 / 卡片 ---------- */
.glass-panel {
  position: relative;
  padding: clamp(20px, 3vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, rgba(14, 95, 134, 0.3), rgba(10, 26, 47, 0.6));
  -webkit-backdrop-filter: blur(12px) saturate(1.15);
  backdrop-filter: blur(12px) saturate(1.15);
}

.plate {
  position: relative;
  padding: clamp(22px, 3vw, 36px);
  border-radius: var(--radius-lg);
  background: var(--c-paper);
  color: var(--paper-tx-1);
  box-shadow: var(--shadow-card);
}

.plate h1,
.plate h2,
.plate h3,
.plate h4 { color: var(--paper-tx-1); }

.plate p,
.plate li { color: var(--paper-tx-2); }

.plate a {
  color: var(--c-lake-deep);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.plate .data { color: var(--c-lake-deep); }

.lift {
  transition:
    transform var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.lift:hover {
  transform: translateY(-4px);
  border-color: var(--line-strong);
  box-shadow: 0 28px 54px -34px rgba(6, 16, 32, 1);
}

/* ---------- 8. 响应式图片容器 ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background-color: var(--c-sky);
  background-image:
    repeating-linear-gradient(90deg, rgba(168, 214, 232, 0.08) 0 1px, transparent 1px 54px),
    repeating-linear-gradient(0deg, rgba(168, 214, 232, 0.06) 0 1px, transparent 1px 54px),
    linear-gradient(140deg, rgba(31, 143, 191, 0.28), rgba(75, 59, 122, 0.34));
}

.media > img,
.media > svg,
.media > video,
.media > picture {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.media--wide { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }

.media__badge {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 7px 14px;
  border-top-right-radius: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: #061020;
  background: var(--c-data);
}

.media__badge--hoop { background: var(--c-hoop); color: #2B1400; }
.media__badge--grass { background: var(--c-grass); color: #05230F; }

.media__caption {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--tx-3);
}

/* ---------- 9. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--tx-3);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb li + li::before {
  content: "/";
  color: var(--tx-3);
  opacity: 0.55;
}

.breadcrumb a { color: var(--tx-2); transition: color var(--dur) var(--ease); }
.breadcrumb a:hover { color: var(--c-lake-mist); }

/* ---------- 10. 显现 ---------- */
html[data-js="on"] [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 420ms var(--ease), transform 420ms var(--ease);
}

html[data-js="on"] [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 11. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 12px;
  left: calc(var(--rail-w) + 12px);
  z-index: 200;
  padding: 11px 20px;
  border-radius: 8px;
  background: var(--c-paper);
  color: var(--paper-tx-1);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  transform: translateY(-180%);
  transition: transform var(--dur) var(--ease);
}

.skip-link:focus { transform: translateY(0); }

/* ---------- 12. 头部 · 品牌轨道 ---------- */
.site-header { position: relative; z-index: 80; }

.rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 95;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 16px 0 20px;
  overflow-y: auto;
  overscroll-behavior: contain;
  background: linear-gradient(180deg, rgba(14, 95, 134, 0.38) 0%, rgba(10, 26, 47, 0.88) 46%, rgba(6, 16, 32, 0.96) 100%);
  border-right: 1px solid var(--line);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
}

.rail__brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 4px 0 16px;
  border-bottom: 1px solid var(--line);
}

.rail__brand-mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: linear-gradient(140deg, var(--c-lake) 0%, var(--c-dusk) 100%);
  box-shadow:
    inset 0 0 0 1px rgba(168, 214, 232, 0.32),
    0 12px 26px -14px rgba(31, 143, 191, 0.95);
  color: #FFFFFF;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 800;
  line-height: 1;
}

.rail__brand-text {
  -webkit-writing-mode: vertical-rl;
  writing-mode: vertical-rl;
  text-orientation: upright;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.22em;
  color: var(--tx-2);
}

.rail__nav { width: 100%; padding: 4px 0; }

.rail__list {
  counter-reset: railidx;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  width: 100%;
}

.rail__item { width: 100%; }

.rail__link {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  width: 100%;
  padding: 10px 4px;
  border-radius: 10px;
  color: var(--tx-2);
  transition:
    color var(--dur) var(--ease),
    background-color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.rail__link::before {
  counter-increment: railidx;
  content: counter(railidx, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 10px;
  line-height: 1;
  letter-spacing: 0.08em;
  color: var(--c-data);
  opacity: 0.55;
  transition: opacity var(--dur) var(--ease);
}

.rail__label {
  -webkit-writing-mode: vertical-rl;
  writing-mode: vertical-rl;
  text-orientation: upright;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.14em;
}

.rail__link:hover {
  color: #FFFFFF;
  background: rgba(31, 143, 191, 0.18);
}

.rail__link:hover::before { opacity: 1; }

.rail__link[aria-current="page"] {
  color: #FFFFFF;
  background: rgba(31, 143, 191, 0.28);
  box-shadow: inset 0 0 0 1px rgba(127, 227, 212, 0.4);
}

.rail__link[aria-current="page"]::before { opacity: 1; }

.rail__status {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--tx-3);
  text-align: center;
}

.rail__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--c-grass);
  box-shadow: 0 0 0 3px rgba(47, 158, 91, 0.22);
}

/* ---------- 13. 头部 · 命令栏 ---------- */
.cmdbar {
  position: fixed;
  top: 0;
  left: var(--rail-w);
  right: 0;
  z-index: 85;
  height: var(--bar-h);
  border-bottom: 1px solid var(--line);
  background: rgba(10, 26, 47, 0.72);
  -webkit-backdrop-filter: blur(16px) saturate(1.2);
  backdrop-filter: blur(16px) saturate(1.2);
  transition: height var(--dur) var(--ease), background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.cmdbar[data-scrolled] {
  height: 50px;
  background: rgba(6, 16, 32, 0.9);
  border-bottom-color: var(--line-strong);
}

.cmdbar__progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  z-index: 2;
  width: 100%;
  height: 2px;
  transform: scaleX(0);
  transform-origin: left center;
  background: linear-gradient(90deg, var(--c-lake) 0%, var(--c-data) 100%);
  pointer-events: none;
}

.cmdbar__inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 24px);
  height: 100%;
  max-width: 1440px;
  padding-inline: clamp(16px, 2.6vw, 36px);
}

.cmdbar__brand {
  display: none;
  flex-direction: column;
  gap: 1px;
  margin-right: auto;
  line-height: 1.15;
}

.cmdbar__brand-cn {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: var(--tx-1);
}

.cmdbar__brand-sub {
  font-size: 10.5px;
  letter-spacing: 0.12em;
  color: var(--tx-3);
}

.cmdbar__now {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-right: auto;
  min-width: 0;
}

.cmdbar__now-label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.18em;
  color: var(--tx-3);
  white-space: nowrap;
}

.cmdbar__now-name {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--tx-1);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.cmdbar__meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--tx-3);
  white-space: nowrap;
}

.cmdbar__live {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--tx-2);
}

.cmdbar__live::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--c-grass);
  box-shadow: 0 0 0 3px rgba(47, 158, 91, 0.2);
}

.cmdbar__cta { flex-shrink: 0; }

/* ---------- 14. 移动导航 ---------- */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  flex-shrink: 0;
  padding: 9px 15px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(14, 95, 134, 0.22);
  color: var(--tx-2);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.nav-toggle:hover {
  color: #FFFFFF;
  border-color: var(--c-dusk-light);
  background: rgba(75, 59, 122, 0.32);
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 10px;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease);
}

.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { bottom: 0; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(4px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-4px) rotate(-45deg); }

.nav-toggle__text { line-height: 1; }

.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 90;
  background: rgba(6, 16, 32, 0.74);
  -webkit-backdrop-filter: blur(3px);
  backdrop-filter: blur(3px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 240ms var(--ease), visibility 240ms var(--ease);
}

.nav-scrim[data-active] {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

/* ---------- 15. 页脚 ---------- */
.site-footer {
  position: relative;
  z-index: 2;
  margin-left: var(--rail-w);
  margin-top: clamp(60px, 8vw, 110px);
  padding: clamp(48px, 7vw, 88px) var(--gutter) 0;
  background: linear-gradient(180deg, rgba(6, 16, 32, 0) 0%, rgba(6, 16, 32, 0.86) 20%, #061020 100%);
  border-top: 1px solid var(--line);
}

.footer__grid {
  display: grid;
  grid-template-columns: minmax(240px, 1.7fr) repeat(3, minmax(140px, 1fr));
  gap: clamp(28px, 4vw, 56px);
  max-width: 1280px;
  padding-bottom: clamp(36px, 5vw, 64px);
  border-bottom: 1px solid var(--line);
}

.footer__brand { min-width: 0; }

.footer__mark {
  font-family: var(--font-display);
  font-size: 30px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--tx-1);
}

.footer__mark::after {
  content: "";
  display: block;
  width: 54px;
  height: 3px;
  margin-top: 14px;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--c-lake) 0%, var(--c-dusk) 100%);
}

.footer__tagline {
  max-width: 30ch;
  margin-top: 18px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--tx-2);
}

.footer__proof {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.05em;
  color: var(--tx-3);
}

.footer__cta { margin-top: 22px; }

.footer__col { min-width: 0; }

.footer__title {
  margin-bottom: 18px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--c-lake-mist);
}

.footer__list {
  display: flex;
  flex-direction: column;
  gap: 11px;
}

.footer__link {
  position: relative;
  display: inline-block;
  font-size: 15px;
  color: var(--tx-2);
  transition: color var(--dur) var(--ease);
}

.footer__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -3px;
  width: 100%;
  height: 1px;
  background: var(--c-lake);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) var(--ease);
}

.footer__link:hover { color: var(--tx-1); }
.footer__link:hover::after { transform: scaleX(1); }

.footer__lines li {
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--tx-2);
  word-break: break-word;
}

.footer__lines li:first-child { color: var(--c-lake-mist); }

.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 28px;
  max-width: 1280px;
  padding: 24px 0 34px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--tx-3);
}

.footer__legal { color: var(--tx-2); }
.footer__copy { margin-right: auto; }
.footer__note { color: var(--tx-3); }

/* ---------- 16. 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: clamp(16px, 3vw, 34px);
  bottom: clamp(16px, 3vw, 34px);
  z-index: 60;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  background: rgba(14, 95, 134, 0.5);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  color: var(--tx-1);
  font-size: 16px;
  line-height: 1;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition:
    opacity var(--dur) var(--ease),
    transform var(--dur) var(--ease),
    background-color var(--dur) var(--ease),
    visibility var(--dur) var(--ease);
}

.to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top:hover {
  transform: translateY(-4px);
  background: rgba(31, 143, 191, 0.62);
}

/* ---------- 17. 响应式 ---------- */
@media (max-width: 1080px) {
  .footer__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .footer__brand { grid-column: 1 / -1; }
  .col-3, .col-4, .col-5 { grid-column: span 6; }
  .col-7, .col-8 { grid-column: span 12; }
}

@media (max-width: 900px) {
  :root {
    --rail-w: 0px;
    --bar-h: 58px;
  }

  #main-content {
    margin-left: 0;
    padding-top: var(--bar-h);
  }

  .skip-link { left: 12px; }

  .rail {
    top: 0;
    bottom: 0;
    width: min(82vw, 306px);
    align-items: stretch;
    gap: 18px;
    padding: 22px 18px 24px;
    background: linear-gradient(180deg, #0E5F86 0%, #0A1A2F 58%, #061020 100%);
    box-shadow: 26px 0 62px -34px rgba(6, 16, 32, 1);
    transform: translateX(-102%);
    transition: transform 240ms var(--ease);
    border-right: 1px solid var(--line-strong);
  }

  .rail[data-open] { transform: translateX(0); }

  .rail__brand {
    flex-direction: row;
    align-items: center;
    justify-content: flex-start;
    gap: 12px;
    padding-bottom: 18px;
  }

  .rail__brand-text {
    -webkit-writing-mode: horizontal-tb;
    writing-mode: horizontal-tb;
    font-size: 13px;
    letter-spacing: 0.2em;
    color: var(--tx-1);
  }

  .rail__nav { padding: 0; }

  .rail__list {
    align-items: stretch;
    gap: 2px;
  }

  .rail__link {
    flex-direction: row;
    align-items: center;
    gap: 12px;
    padding: 12px 14px;
    border-radius: 10px;
  }

  .rail__link::before { font-size: 11px; }

  .rail__label {
    -webkit-writing-mode: horizontal-tb;
    writing-mode: horizontal-tb;
    font-size: 15px;
    letter-spacing: 0.08em;
  }

  .rail__status {
    flex-direction: row;
    justify-content: flex-start;
    gap: 10px;
    padding-top: 18px;
    font-size: 12px;
    text-align: left;
  }

  .cmdbar { left: 0; }

  .cmdbar__brand { display: flex; }
  .cmdbar__now,
  .cmdbar__meta { display: none; }

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

  .site-footer {
    margin-left: 0;
    padding-top: clamp(40px, 9vw, 64px);
  }

  .grid-12 { gap: 18px; }
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8 { grid-column: span 12; }
}

@media (max-width: 620px) {
  body { font-size: 16px; }

  .footer__grid { grid-template-columns: minmax(0, 1fr); }
  .footer__bottom { flex-direction: column; align-items: flex-start; gap: 8px; }
  .footer__copy { margin-right: 0; }
}

@media (max-width: 480px) {
  .cmdbar__cta {
    padding: 8px 14px;
    font-size: 13px;
  }
  .nav-toggle {
    padding: 8px 12px;
    font-size: 12px;
  }
  .nav-toggle__text { display: none; }
}

/* ---------- 18. 降低动态效果 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  html[data-js="on"] [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .lift:hover,
  .btn:hover,
  .to-top:hover {
    transform: none;
  }
}