/* ============================================================
   立即博体育站 · 共享样式 /assets/site.css
   深空蓝底 + 电光青交互 + 橙红赛事高亮 + 暖纸编辑章节
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root {
  --ink-900: #060B1E;
  --ink-800: #0C1836;
  --ink-700: #14264F;
  --line: #27406F;
  --cyan: #26E0D6;
  --cyan-soft: #9BF6F0;
  --orange: #FF5A2B;
  --amber: #FFB03A;
  --paper: #F4EEE2;
  --paper-ink: #141110;
  --paper-link: #0A6B64;
  --paper-muted: #4A4643;
  --mist: #8A93A8;
  --white: #F2F6FF;

  --rail-w: 0px;
  --radius: 20px;
  --radius-lg: 28px;
  --pill: 999px;
  --edge: clamp(16px, 4vw, 40px);
  --maxw: 1280px;

  --font: "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: ui-monospace, "SFMono-Regular", "Menlo", "Consolas", "Courier New", monospace;
}

@media (min-width: 1024px) {
  :root { --rail-w: 88px; }
}

/* ---------- 2. 重置与基础 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  padding-left: var(--rail-w);
  padding-top: 96px;
  background: var(--ink-900);
  color: var(--white);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: .005em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  margin: 0 0 .55em;
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -.012em;
  color: inherit;
}

p { margin: 0 0 1.1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--cyan); text-decoration: none; }
a:hover { color: var(--cyan-soft); }

ul, ol { margin: 0 0 1.1em; padding-left: 1.2em; }

strong, b { font-weight: 800; }

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

button { font-family: inherit; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

#main-content { scroll-margin-top: 96px; }

[data-chapter] { scroll-margin-top: 108px; }

/* ---------- 3. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 12px;
  left: calc(var(--rail-w) + 12px);
  z-index: 300;
  padding: 10px 20px;
  border-radius: var(--pill);
  background: var(--cyan);
  color: var(--ink-900);
  font-weight: 800;
  font-size: 14px;
  text-decoration: none;
  transform: translateY(-180%);
  transition: transform .18s ease-out;
}
.skip-link:focus-visible {
  transform: none;
  outline: 2px solid var(--white);
  outline-offset: 3px;
}

/* ---------- 4. 左侧品牌轨道 ---------- */
.rail {
  position: fixed;
  inset-block: 0;
  inset-inline-start: 0;
  width: 88px;
  z-index: 70;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 20px 0 24px;
  background: linear-gradient(180deg, var(--ink-800) 0%, var(--ink-900) 100%);
  border-right: 1px solid var(--line);
}

.rail__mark {
  flex: 0 0 auto;
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: 13px;
  background: linear-gradient(150deg, var(--cyan) 0%, #1AA8C9 100%);
  color: var(--ink-900);
  font-size: 15px;
  font-weight: 900;
  letter-spacing: .02em;
  transform: skewX(-8deg);
}

.rail__word {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 13px;
  font-weight: 900;
  letter-spacing: .42em;
  color: rgba(242, 246, 255, .82);
  padding-top: 4px;
}

.rail__track {
  position: relative;
  flex: 1 1 auto;
  width: 2px;
  border-radius: 2px;
  background: var(--line);
  overflow: hidden;
}

.rail__progress {
  position: absolute;
  inset-block-start: 0;
  inset-inline: 0;
  height: 0;
  background: linear-gradient(180deg, var(--orange) 0%, var(--cyan) 100%);
  transition: height .12s linear;
}

.rail__dots {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 11px;
  margin-bottom: 2px;
}

.rail__dot {
  width: 9px;
  height: 9px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: var(--line);
  cursor: pointer;
  transition: background-color .2s ease-out, transform .2s ease-out, box-shadow .2s ease-out;
}
.rail__dot:hover { background: var(--cyan-soft); transform: scale(1.25); }
.rail__dot.is-active {
  background: var(--orange);
  transform: scale(1.45);
  box-shadow: 0 0 0 4px rgba(255, 90, 43, .18);
}

@media (max-width: 1023px) {
  .rail { display: none; }
}

/* ---------- 5. 悬浮胶囊头部 ---------- */
.site-header {
  position: fixed;
  inset-block-start: 0;
  inset-inline-start: var(--rail-w);
  inset-inline-end: 0;
  z-index: 200;
  padding: 14px clamp(12px, 3vw, 28px);
  pointer-events: none;
}

.topbar {
  position: relative;
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: 12px;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 10px 10px 10px 16px;
  border-radius: var(--pill);
  background: rgba(12, 24, 54, .9);
  border: 1px solid var(--line);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  transition: padding .18s ease-out, background-color .18s ease-out, border-color .18s ease-out;
}
.topbar[data-compact="true"] {
  padding: 6px 8px 6px 14px;
  background: rgba(9, 18, 42, .96);
  border-color: #31508A;
}

.topbar__brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
  text-decoration: none;
  flex: 0 0 auto;
}
.topbar__brand:hover { color: var(--white); }

.topbar__mark {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: linear-gradient(150deg, var(--cyan) 0%, #1AA8C9 100%);
  color: var(--ink-900);
  font-size: 13px;
  font-weight: 900;
  transform: skewX(-8deg);
  flex: 0 0 auto;
}

.topbar__text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.topbar__name {
  font-size: 15px;
  font-weight: 900;
  letter-spacing: .03em;
  color: var(--white);
}

.topbar__tag {
  font-style: normal;
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--mist);
  white-space: nowrap;
}

.topbar__nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: center;
  min-width: 0;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-list__item { margin: 0; }

.nav-list__link {
  display: block;
  padding: 8px 14px;
  border-radius: var(--pill);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .01em;
  color: var(--white);
  text-decoration: none;
  white-space: nowrap;
  transition: background-color .2s ease-out, color .2s ease-out;
}
.nav-list__link:hover {
  background: var(--ink-700);
  color: var(--cyan-soft);
}
.nav-list__link[aria-current="page"] {
  background: var(--cyan);
  color: var(--ink-900);
}
.nav-list__link[aria-current="page"]:hover {
  background: var(--cyan-soft);
  color: var(--ink-900);
}

.topbar__cta {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  padding: 9px 18px;
  border-radius: var(--pill);
  background: var(--orange);
  color: var(--paper-ink);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: .02em;
  text-decoration: none;
  transition: background-color .2s ease-out, transform .2s ease-out;
}
.topbar__cta:hover {
  background: var(--amber);
  color: var(--paper-ink);
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 9px 16px;
  border-radius: var(--pill);
  border: 1px solid var(--line);
  background: var(--ink-700);
  color: var(--white);
  font-size: 13px;
  font-weight: 800;
  cursor: pointer;
}
.nav-toggle:hover { border-color: var(--cyan); color: var(--cyan-soft); }

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 16px;
}

.nav-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform .18s ease-out, opacity .18s ease-out;
}

.topbar[data-open="true"] .nav-toggle__bar:first-child { transform: translateY(3px) rotate(45deg); }
.topbar[data-open="true"] .nav-toggle__bar:last-child { transform: translateY(-3px) rotate(-45deg); }

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

/* ---------- 6. 布局容器 ---------- */
.shell {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--edge);
}

.section {
  position: relative;
  padding-block: clamp(56px, 8vw, 112px);
}

.section--paper {
  background: var(--paper);
  color: var(--paper-ink);
  -webkit-clip-path: polygon(0 24px, 100% 0, 100% 100%, 0 100%);
  clip-path: polygon(0 24px, 100% 0, 100% 100%, 0 100%);
  padding-block: clamp(72px, 9vw, 128px);
}
.section--paper h1,
.section--paper h2,
.section--paper h3,
.section--paper h4 { color: var(--paper-ink); }
.section--paper a { color: var(--paper-link); }
.section--paper a:hover { color: #075049; }
.section--paper .eyebrow { color: var(--paper-link); }
.section--paper .card {
  background: #FFFDF8;
  border-color: rgba(20, 17, 16, .14);
  color: var(--paper-ink);
}
.section--paper .card__kicker { color: var(--paper-link); }
.section--paper .stat__label,
.section--paper .lede,
.section--paper .accordion__panel { color: var(--paper-muted); }
.section--paper .stat__num { color: var(--paper-link); }

.section__head {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 780px;
  margin-bottom: clamp(28px, 4vw, 52px);
}

/* ---------- 7. 文字层级 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .7em;
  margin: 0;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--cyan);
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
}

.display-title {
  margin: 0;
  font-size: clamp(2.6rem, 7vw, 5.4rem);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: -.02em;
  transform: skewX(-5deg);
  transform-origin: left bottom;
}

.lede {
  max-width: 60ch;
  font-size: clamp(1rem, 1.5vw, 1.125rem);
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 8. 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 24px);
}
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(238px, 1fr)); }

/* ---------- 9. 卡片 ---------- */
.card {
  position: relative;
  padding: clamp(20px, 2.4vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-700);
  overflow: hidden;
  transition: border-color .2s ease-out, transform .2s ease-out;
}
.card::before {
  content: "";
  position: absolute;
  inset-block: 12px;
  inset-inline-start: 0;
  width: 4px;
  border-radius: 0 4px 4px 0;
  background: var(--cyan);
}
.card:hover { border-color: #3A5C9C; }
.card--event::before { background: var(--orange); }
.card--data::before { background: var(--cyan); }
.card--flow::before { background: var(--amber); }

.card__kicker {
  display: block;
  margin-bottom: 10px;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.card__title {
  margin: 0 0 .5em;
  font-size: clamp(1.1rem, 2vw, 1.4rem);
  font-weight: 900;
  line-height: 1.25;
}
.card__title:last-child { margin-bottom: 0; }

/* ---------- 10. 数据 ---------- */
.stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.stat__num {
  font-family: var(--mono);
  font-size: clamp(2rem, 4.6vw, 3.4rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.stat__label {
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--mist);
}

/* ---------- 11. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .55em;
  padding: .85em 1.6em;
  border: 1px solid transparent;
  border-radius: var(--pill);
  font-size: 15px;
  font-weight: 800;
  letter-spacing: .02em;
  line-height: 1.3;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .2s ease-out, color .2s ease-out, border-color .2s ease-out, transform .2s ease-out;
}
.btn:hover { transform: translateY(-1px); }

.btn--cyan { background: var(--cyan); color: var(--ink-900); }
.btn--cyan:hover { background: var(--cyan-soft); color: var(--ink-900); }

.btn--ghost { background: transparent; border-color: var(--line); color: var(--white); }
.btn--ghost:hover { border-color: var(--cyan); color: var(--cyan); }

.btn--ink { background: var(--paper-ink); color: var(--paper); }
.btn--ink:hover { background: #2A2320; color: var(--paper); }

.btn--accent { background: var(--orange); color: var(--paper-ink); }
.btn--accent:hover { background: var(--amber); color: var(--paper-ink); }

/* ---------- 12. 筛选芯片 ---------- */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: .5em;
  padding: 7px 16px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: transparent;
  color: var(--white);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .02em;
  cursor: pointer;
  transition: background-color .2s ease-out, border-color .2s ease-out, color .2s ease-out;
}
.chip:hover { border-color: var(--cyan); color: var(--cyan-soft); }
.chip[aria-pressed="true"],
.chip.is-active {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink-900);
}

/* ---------- 13. 折叠组件 ---------- */
.accordion {
  border-top: 1px solid var(--line);
}
.section--paper .accordion { border-top-color: rgba(20, 17, 16, .18); }

.accordion__item {
  border-bottom: 1px solid var(--line);
}
.section--paper .accordion__item { border-bottom-color: rgba(20, 17, 16, .18); }

.accordion__trigger {
  width: 100%;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 0;
  background: none;
  border: 0;
  color: inherit;
  font-family: inherit;
  font-size: 16px;
  font-weight: 800;
  line-height: 1.5;
  text-align: left;
  cursor: pointer;
}
.accordion__trigger::after {
  content: "+";
  flex: 0 0 auto;
  font-size: 1.35em;
  line-height: 1;
  font-weight: 800;
  color: var(--cyan);
  transition: color .2s ease-out;
}
.section--paper .accordion__trigger::after { color: var(--paper-link); }
.accordion__item[data-open="true"] .accordion__trigger::after { content: "–"; }

.accordion__panel {
  padding: 0 0 20px;
  font-size: 15px;
  color: var(--mist);
  max-width: 68ch;
}
.accordion__panel[hidden] { display: none; }

/* ---------- 14. 面包屑 ---------- */
.breadcrumb { margin-bottom: clamp(20px, 3vw, 32px); }

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  color: var(--mist);
}
.breadcrumb__list li {
  display: inline-flex;
  align-items: center;
}
.breadcrumb__list li + li::before {
  content: "/";
  margin-inline: 8px;
  opacity: .5;
}
.breadcrumb__link {
  color: var(--mist);
  text-decoration: none;
}
.breadcrumb__link:hover { color: var(--cyan); }

/* ---------- 15. 图片容器 ---------- */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--ink-800);
  background-image:
    linear-gradient(140deg, rgba(38, 224, 214, .12) 0%, rgba(6, 11, 30, 0) 55%),
    repeating-linear-gradient(115deg, rgba(39, 64, 111, .55) 0 1px, transparent 1px 20px);
}

.media-frame__img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }

/* ---------- 16. 复制按钮 ---------- */
.copy-btn {
  flex: 0 0 auto;
  padding: 3px 11px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: transparent;
  color: var(--mist);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .08em;
  cursor: pointer;
  transition: border-color .2s ease-out, color .2s ease-out;
}
.copy-btn:hover { border-color: var(--cyan); color: var(--cyan); }
.copy-btn[data-state="done"] { border-color: var(--amber); color: var(--amber); }

/* ---------- 17. 显现动画 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .5s ease-out, transform .5s ease-out;
}
[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 18. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--ink-800);
  border-top: 1px solid var(--line);
  margin-top: clamp(48px, 7vw, 96px);
}

.foot-cta {
  background: var(--paper);
  color: var(--paper-ink);
  -webkit-clip-path: polygon(0 0, 100% 30px, 100% 100%, 0 100%);
  clip-path: polygon(0 0, 100% 30px, 100% 100%, 0 100%);
  padding-top: 30px;
}

.foot-cta__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: clamp(32px, 5vw, 56px) var(--edge) clamp(36px, 5vw, 60px);
}

.foot-cta__lead { max-width: 34ch; }

.foot-cta__kicker { color: var(--paper-link); margin-bottom: 10px; }

.foot-cta__title {
  margin: 0;
  font-size: clamp(1.5rem, 3.2vw, 2.3rem);
  font-weight: 900;
  line-height: 1.15;
  color: var(--paper-ink);
  transform: skewX(-4deg);
  transform-origin: left bottom;
}

.foot-main { padding-block: clamp(40px, 6vw, 68px); }

.foot-main__inner {
  display: grid;
  grid-template-columns: 1.1fr 1.5fr 1.1fr;
  gap: clamp(28px, 4vw, 56px);
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--edge);
}

.foot-brand__mark {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  background: linear-gradient(150deg, var(--cyan) 0%, #1AA8C9 100%);
  color: var(--ink-900);
  font-size: 14px;
  font-weight: 900;
  transform: skewX(-8deg);
  margin-bottom: 14px;
}

.foot-brand__name {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 900;
  letter-spacing: .02em;
  color: var(--white);
}

.foot-brand__line {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
  max-width: 30ch;
}

.foot-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.foot-col { display: flex; flex-direction: column; align-items: flex-start; }

.foot-col__title {
  margin: 0 0 14px;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.foot-col__link {
  display: inline-block;
  padding: 5px 0;
  font-size: 14px;
  font-weight: 600;
  color: rgba(242, 246, 255, .84);
  text-decoration: none;
  transition: color .2s ease-out, transform .2s ease-out;
}
.foot-col__link:hover {
  color: var(--cyan);
  transform: translateX(2px);
}

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

.foot-contact__row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.foot-contact__label {
  font-size: 10px;
  font-weight: 800;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--mist);
  flex: 0 0 auto;
}

.foot-contact__value {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .01em;
  color: var(--white);
  word-break: break-all;
}

.foot-contact__note {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

.foot-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 20px;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 18px var(--edge) 24px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--mist);
}
.foot-base p { margin: 0; }
.foot-base__icp { font-family: var(--mono); }

/* ---------- 19. 返回顶部 ---------- */
.to-top {
  position: fixed;
  inset-inline-end: clamp(14px, 3vw, 28px);
  inset-block-end: clamp(14px, 3vw, 28px);
  z-index: 240;
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border: 0;
  border-radius: 50%;
  background: var(--cyan);
  color: var(--ink-900);
  font-size: 19px;
  font-weight: 900;
  line-height: 1;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(14px);
  transition: opacity .22s ease-out, transform .22s ease-out, background-color .2s ease-out;
  box-shadow: 0 10px 28px rgba(6, 11, 30, .55);
}
.to-top:hover { background: var(--cyan-soft); }
.to-top.is-on {
  opacity: 1;
  pointer-events: auto;
  transform: none;
}

/* ---------- 20. 移动端快捷条 ---------- */
.quickbar { display: none; }

/* ---------- 21. 响应式 ---------- */
@media (max-width: 1099px) {
  .nav-list__link { padding: 8px 11px; font-size: 13px; }
  .topbar__tag { display: none; }
  .foot-main__inner { grid-template-columns: 1fr 1fr; }
  .foot-brand { grid-column: 1 / -1; }
}

@media (max-width: 899px) {
  body { padding-top: 88px; padding-bottom: 84px; }

  .topbar {
    flex-wrap: wrap;
    padding: 8px 8px 8px 14px;
    border-radius: 26px;
  }
  .topbar[data-compact="true"] { padding: 8px 8px 8px 14px; }

  .topbar__brand { margin-right: auto; }

  .topbar__cta { display: none; }

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

  .topbar__nav {
    position: absolute;
    inset-block-start: calc(100% + 10px);
    inset-inline: 0;
    display: none;
    flex: 1 0 100%;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 24px;
    background: rgba(9, 18, 42, .98);
    box-shadow: 0 24px 48px rgba(0, 0, 0, .45);
  }
  .topbar[data-open="true"] .topbar__nav { display: block; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    width: 100%;
  }
  .nav-list__link {
    padding: 12px 16px;
    border-radius: 16px;
    font-size: 15px;
  }

  .foot-cta__inner { flex-direction: column; align-items: flex-start; }
  .foot-main__inner { grid-template-columns: 1fr; gap: 34px; }
  .foot-cols { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
  .foot-base { flex-direction: column; align-items: flex-start; }

  .quickbar {
    position: fixed;
    inset-inline: 10px;
    inset-block-end: 10px;
    z-index: 250;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 4px;
    padding: 8px;
    border: 1px solid var(--line);
    border-radius: 24px;
    background: rgba(12, 24, 54, .96);
    -webkit-backdrop-filter: blur(14px);
    backdrop-filter: blur(14px);
    box-shadow: 0 18px 40px rgba(0, 0, 0, .5);
  }

  .quickbar__link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: 7px 2px;
    border-radius: 16px;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .02em;
    color: rgba(242, 246, 255, .8);
    text-decoration: none;
    transition: background-color .2s ease-out, color .2s ease-out;
  }
  .quickbar__link:hover { color: var(--cyan); }
  .quickbar__link[aria-current="page"] {
    background: var(--ink-700);
    color: var(--cyan);
  }

  .quickbar__icon {
    font-size: 15px;
    line-height: 1;
    color: currentColor;
  }

  .to-top { inset-block-end: 92px; }
}

@media (max-width: 560px) {
  body { font-size: 15px; }
  .topbar__name { font-size: 14px; }
  .foot-cols { grid-template-columns: 1fr; }
  .display-title { font-size: clamp(2.1rem, 11vw, 3rem); }
  .section--paper {
    -webkit-clip-path: polygon(0 16px, 100% 0, 100% 100%, 0 100%);
    clip-path: polygon(0 16px, 100% 0, 100% 100%, 0 100%);
  }
}

/* ---------- 22. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .btn:hover,
  .topbar__cta:hover,
  .foot-col__link:hover { transform: none; }
}