/* ===========================================================
   易倍赛场 · 共享样式表 /assets/site.css
   深墨绿夜场底色 + 荧光青结构高亮 + 暖橙变动提示
   =========================================================== */

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

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

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 {
  display: block;
  max-width: 100%;
}

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

button { background: none; border: 0; }

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

/* ---------- 2. 变量 ---------- */
:root {
  --ink-950: #05130F;
  --ink-900: #0A2620;
  --ink-800: #12362C;
  --ink-700: #1B4A3C;
  --cyan-400: #35F0C6;
  --cyan-200: #9BF7E0;
  --orange-500: #FF8A3D;
  --orange-200: #FFC79B;
  --mist-100: #E9F5F0;
  --chalk: #FFFFFF;
  --slate-400: #8FB3A7;
  --light-50: #F1F7F4;
  --cyan-deep: #0B6C55;

  --font-display: 'Barlow Condensed', 'Oswald', 'Arial Narrow', 'Helvetica Neue', sans-serif;
  --font-cn: 'Noto Sans SC', 'Source Han Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;

  --chamfer: 12px;
  --header-h: 76px;
  --wrap-max: 1200px;
  --gutter: clamp(18px, 4vw, 44px);
  --radius-line: 1px;

  --ease-out: cubic-bezier(.22, .61, .36, 1);
}

@media (max-width: 640px) {
  :root { --header-h: 64px; }
}

/* ---------- 3. 基础排版 ---------- */
body {
  background-color: var(--ink-900);
  background-image:
    linear-gradient(180deg, rgba(5, 19, 15, .92) 0%, rgba(10, 38, 32, 0) 420px),
    linear-gradient(180deg, rgba(53, 240, 198, .05) 0%, rgba(53, 240, 198, 0) 1px);
  background-repeat: no-repeat;
  color: var(--mist-100);
  font-family: var(--font-cn);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.65;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-cn);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -.01em;
  color: var(--chalk);
}

h1 { font-size: clamp(30px, 4.6vw, 56px); }
h2 { font-size: clamp(24px, 3.4vw, 44px); }
h3 { font-size: clamp(19px, 2.2vw, 26px); }
h4 { font-size: clamp(16px, 1.6vw, 19px); }

p { margin-bottom: 1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--cyan-200); transition: color .2s ease, border-color .2s ease; }
a:hover { color: var(--cyan-400); }

strong { color: var(--chalk); font-weight: 600; }

abbr[title] { text-decoration: none; border-bottom: 1px dotted var(--ink-700); }

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

::selection {
  background: var(--cyan-400);
  color: var(--ink-950);
}

/* ---------- 4. 容器与章节 ---------- */
.wrap {
  width: 100%;
  max-width: calc(var(--wrap-max) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: clamp(48px, 8vw, 104px);
}

.section--tight { padding-block: clamp(30px, 4.6vw, 60px); }
.section--flush { padding-top: 0; }

.page-top {
  padding-top: calc(var(--header-h) + clamp(26px, 5vw, 64px));
}

#main-content {
  display: block;
  scroll-margin-top: calc(var(--header-h) + 20px);
}

/* ---------- 5. 跳过链接 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 12px;
  z-index: 300;
  display: inline-block;
  padding: 10px 20px;
  background: var(--cyan-400);
  color: var(--ink-950);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .06em;
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
  transform: translateY(-220%);
  transition: transform .22s var(--ease-out);
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline-offset: 4px;
}

/* ---------- 6. 头部 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 120;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color .28s ease, border-color .28s ease, box-shadow .28s ease;
}

.site-header[data-stuck] {
  background-color: rgba(10, 38, 32, .96);
  border-bottom-color: var(--ink-700);
  box-shadow: 0 14px 34px -26px rgba(5, 19, 15, .95);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2.2vw, 30px);
  width: 100%;
  max-width: calc(var(--wrap-max) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
  height: var(--header-h);
}

/* 品牌 */
.brand {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 1px;
  flex: 0 0 auto;
  text-decoration: none;
}

.brand-mark {
  position: relative;
  font-family: var(--font-cn);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--chalk);
  line-height: 1.2;
}

.brand-mark::after {
  content: "";
  display: inline-block;
  width: 9px;
  height: 9px;
  margin-left: 9px;
  background: var(--cyan-400);
  transform: translateY(-2px) skewX(-16deg);
}

.brand-sub {
  font-size: 11px;
  font-weight: 400;
  letter-spacing: .16em;
  color: var(--slate-400);
  line-height: 1.3;
}

.brand:hover .brand-mark { color: var(--cyan-200); }

/* 导航 */
.site-nav {
  flex: 1 1 auto;
  min-width: 0;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 3px;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.nav-list::-webkit-scrollbar { display: none; }

.nav-link {
  display: inline-flex;
  align-items: center;
  height: 34px;
  padding: 0 13px;
  white-space: nowrap;
  font-size: 13.5px;
  font-weight: 500;
  letter-spacing: .07em;
  color: var(--mist-100);
  border: 1px solid transparent;
  border-radius: 2px;
  transition: background-color .2s ease, color .2s ease, border-color .2s ease;
}

.nav-link:hover,
.nav-link:focus-visible {
  background: var(--ink-800);
  border-color: var(--ink-700);
  color: var(--cyan-200);
}

.nav-link[aria-current="page"] {
  background: var(--cyan-400);
  border-color: var(--cyan-400);
  color: var(--ink-950);
  font-weight: 700;
}

.nav-extra { display: none; }

/* 右侧区 */
.header-aside {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  margin-left: auto;
}

.round-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px 6px 10px;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .05em;
  color: var(--cyan-200);
  background: rgba(53, 240, 198, .09);
  border: 1px solid rgba(53, 240, 198, .32);
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
  white-space: nowrap;
}

.round-chip-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan-400);
  box-shadow: 0 0 0 3px rgba(53, 240, 198, .2);
  flex: 0 0 auto;
}

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  place-items: center;
  width: 44px;
  height: 38px;
  padding: 0;
  color: var(--mist-100);
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  cursor: pointer;
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
  transition: background-color .2s ease, color .2s ease;
}

.nav-toggle:hover { background: var(--ink-700); color: var(--cyan-400); }

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: background-color .2s ease;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform .22s var(--ease-out), top .22s var(--ease-out), background-color .2s ease;
}

.nav-toggle-bars::before { top: -5px; }
.nav-toggle-bars::after { top: 5px; }

[data-nav-toggle][aria-expanded="true"] .nav-toggle-bars { background: transparent; }
[data-nav-toggle][aria-expanded="true"] .nav-toggle-bars::before {
  top: 0;
  background: var(--cyan-400);
  transform: rotate(45deg);
}
[data-nav-toggle][aria-expanded="true"] .nav-toggle-bars::after {
  top: 0;
  background: var(--cyan-400);
  transform: rotate(-45deg);
}

/* 阅读进度 */
.scroll-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan-400) 0%, var(--cyan-400) 62%, var(--orange-500) 100%);
  transform: scaleX(0);
  transform-origin: 0 50%;
  pointer-events: none;
}

/* ---------- 7. 按钮 ---------- */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 42px;
  padding: 0 18px;
  font-family: var(--font-cn);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .05em;
  line-height: 1;
  white-space: nowrap;
  cursor: pointer;
  background: var(--ink-800);
  color: var(--mist-100);
  border: 1px solid var(--ink-700);
  clip-path: polygon(10px 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%, 0 10px);
  transition: background-color .2s ease, color .2s ease, border-color .2s ease;
}

.btn:hover {
  background: var(--ink-700);
  border-color: var(--cyan-400);
  color: var(--cyan-200);
}

.btn:focus-visible {
  outline: none;
  box-shadow: inset 0 0 0 2px var(--cyan-400);
}

.btn-primary {
  background: var(--cyan-400);
  border-color: var(--cyan-400);
  color: var(--ink-950);
}

.btn-primary:hover {
  background: var(--cyan-200);
  border-color: var(--cyan-200);
  color: var(--ink-950);
}

.btn-primary:focus-visible { box-shadow: inset 0 0 0 2px var(--ink-950); }

.btn-orange {
  background: var(--orange-500);
  border-color: var(--orange-500);
  color: var(--ink-950);
}

.btn-orange:hover {
  background: var(--orange-200);
  border-color: var(--orange-200);
  color: var(--ink-950);
}

.btn-orange:focus-visible { box-shadow: inset 0 0 0 2px var(--ink-950); }

.btn-ghost {
  background: transparent;
  border-color: var(--ink-700);
  color: var(--cyan-200);
}

.btn-ghost:hover { background: rgba(53, 240, 198, .1); }

.btn-block { display: flex; width: 100%; }

/* ---------- 8. 章节语言 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--cyan-400);
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--cyan-400);
  flex: 0 0 auto;
}

.eyebrow--orange { color: var(--orange-200); }
.eyebrow--orange::before { background: var(--orange-500); }

.chapter {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.chapter-num {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(30px, 4.4vw, 54px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--cyan-400);
  font-variant-numeric: tabular-nums;
}

.section-head {
  display: grid;
  gap: clamp(10px, 1.6vw, 18px);
  max-width: 820px;
  margin-bottom: clamp(22px, 3.2vw, 44px);
}

.lede {
  max-width: 720px;
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.6;
  color: var(--cyan-200);
}

.prose { max-width: 680px; }
.prose p { line-height: 1.8; }
.prose ul, .prose ol { padding-left: 1.25em; margin-bottom: 1em; }
.prose ul { list-style: none; }
.prose ul li { position: relative; padding-left: 4px; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: -16px;
  top: .72em;
  width: 8px;
  height: 2px;
  background: var(--cyan-400);
}
.prose ol { list-style: decimal; }
.prose li { margin-bottom: .5em; line-height: 1.75; }

.ribbon {
  height: 8px;
  width: 100%;
  background: var(--cyan-400);
}

.ribbon--orange { background: var(--orange-500); }

.track-line {
  height: 1px;
  width: 100%;
  background-image: repeating-linear-gradient(90deg, var(--ink-700) 0 10px, transparent 10px 20px);
}

.divider {
  height: 1px;
  width: 100%;
  background: var(--ink-700);
}

/* ---------- 9. 面板 / 标签 / 数据 ---------- */
.panel {
  position: relative;
  padding: clamp(18px, 2.4vw, 30px);
  background: linear-gradient(180deg, var(--ink-800) 0%, var(--ink-900) 100%);
  clip-path: polygon(var(--chamfer) 0, 100% 0, 100% calc(100% - var(--chamfer)), calc(100% - var(--chamfer)) 100%, 0 100%, 0 var(--chamfer));
}

.panel--flat { background: var(--ink-800); }

.panel--outline {
  background: transparent;
  box-shadow: inset 0 0 0 1px var(--ink-700);
}

.panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.panel-title {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .08em;
  color: var(--chalk);
}

.panel-note {
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--slate-400);
}

.tag {
  display: inline-flex;
  align-items: center;
  height: 24px;
  padding: 0 10px;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .08em;
  color: var(--cyan-200);
  background: rgba(155, 247, 224, .12);
  border: 1px solid rgba(155, 247, 224, .3);
  white-space: nowrap;
}

.tag--orange {
  color: var(--orange-200);
  background: rgba(255, 138, 61, .14);
  border-color: rgba(255, 138, 61, .36);
}

.stat { display: grid; gap: 6px; }

.stat-num {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(56px, 11vw, 168px);
  line-height: .86;
  letter-spacing: -.02em;
  color: var(--chalk);
  font-variant-numeric: tabular-nums;
}

.stat-num--mid { font-size: clamp(38px, 6vw, 82px); }
.stat-num--sm { font-size: clamp(26px, 3.4vw, 46px); }
.stat-num--cyan { color: var(--cyan-400); }
.stat-num--orange { color: var(--orange-500); }

.stat-label {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .08em;
  color: var(--slate-400);
}

.stat-delta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: .04em;
  color: var(--orange-200);
}

.num-text { font-variant-numeric: tabular-nums; }

/* ---------- 10. 影像容器 ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  width: 100%;
  background: var(--ink-800);
  clip-path: polygon(14px 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%, 0 14px);
}

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

.media--wide { aspect-ratio: 16 / 9; }
.media--band { aspect-ratio: 21 / 9; }
.media--square { aspect-ratio: 1 / 1; }
.media--tall { aspect-ratio: 3 / 4; }

.media--placeholder {
  background-color: var(--ink-800);
  background-image:
    repeating-linear-gradient(135deg, rgba(53, 240, 198, .1) 0 2px, transparent 2px 14px),
    radial-gradient(120% 90% at 12% 0%, rgba(53, 240, 198, .22) 0%, rgba(53, 240, 198, 0) 55%),
    linear-gradient(160deg, var(--ink-800) 0%, var(--ink-950) 100%);
}

.media--placeholder::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 42%;
  background: linear-gradient(180deg, rgba(5, 19, 15, 0) 0%, rgba(5, 19, 15, .78) 100%);
  pointer-events: none;
}

.media-fallback {
  position: absolute;
  left: clamp(14px, 2vw, 22px);
  bottom: clamp(14px, 2vw, 22px);
  z-index: 2;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .1em;
  color: var(--cyan-200);
}

.media-caption {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--slate-400);
}

/* ---------- 11. 栅格 ---------- */
.grid {
  display: grid;
  gap: clamp(16px, 2.2vw, 28px);
}

.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.grid--offset { align-items: start; }

@media (max-width: 1020px) {
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 620px) {
  .grid-2,
  .grid-3,
  .grid-4 { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- 12. 面包屑 ---------- */
.crumbs {
  font-size: 13px;
  letter-spacing: .05em;
  color: var(--slate-400);
}

.crumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

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

.crumbs li + li::before {
  content: "/";
  color: var(--ink-700);
}

.crumbs a {
  color: var(--slate-400);
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
}

.crumbs a:hover {
  color: var(--cyan-400);
  border-bottom-color: var(--cyan-400);
}

.crumbs [aria-current="page"] { color: var(--mist-100); }

/* ---------- 13. 浅色阅读区 ---------- */
.light-zone {
  background: var(--light-50);
  color: var(--ink-900);
}

.light-zone h1,
.light-zone h2,
.light-zone h3,
.light-zone h4 { color: var(--ink-950); }

.light-zone .lede { color: var(--cyan-deep); }
.light-zone a { color: var(--cyan-deep); }
.light-zone a:hover { color: var(--ink-950); }
.light-zone .stat-label,
.light-zone .panel-note,
.light-zone .media-caption { color: #4C6B61; }
.light-zone .divider { background: #CFE2DA; }
.light-zone .panel { background: #FFFFFF; }
.light-zone .panel--outline { background: transparent; box-shadow: inset 0 0 0 1px #CFE2DA; }
.light-zone .eyebrow { color: var(--cyan-deep); }
.light-zone .eyebrow::before { background: var(--cyan-deep); }
.light-zone .btn { background: var(--ink-900); border-color: var(--ink-900); color: var(--light-50); }
.light-zone .btn:hover { background: var(--ink-800); border-color: var(--cyan-deep); color: var(--cyan-200); }
.light-zone .btn-primary { background: var(--cyan-deep); border-color: var(--cyan-deep); color: #FFFFFF; }
.light-zone .btn-primary:hover { background: var(--ink-900); color: var(--cyan-200); }

/* ---------- 14. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 120px);
  background: var(--ink-950);
  border-top: 1px solid var(--ink-700);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -3px;
  left: 0;
  width: min(320px, 42%);
  height: 3px;
  background: var(--cyan-400);
}

.footer-top {
  display: grid;
  grid-template-columns: 1.5fr repeat(4, minmax(0, 1fr));
  gap: clamp(22px, 3vw, 44px);
  padding-block: clamp(40px, 6vw, 76px) clamp(28px, 4vw, 52px);
}

.brand--footer { margin-bottom: 14px; }

.footer-blurb {
  max-width: 300px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--slate-400);
  margin-bottom: 14px;
}

.footer-tip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .08em;
  color: var(--cyan-200);
  margin: 0;
}

.footer-tip::before {
  content: "";
  width: 7px;
  height: 7px;
  background: var(--cyan-400);
  transform: skewX(-16deg);
  flex: 0 0 auto;
}

.footer-col-title {
  margin: 0 0 16px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .16em;
  color: var(--cyan-400);
}

.footer-list {
  display: grid;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-list a {
  display: inline-block;
  font-size: 14.5px;
  line-height: 1.5;
  color: var(--mist-100);
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}

.footer-list a:hover {
  color: var(--cyan-400);
  border-bottom-color: var(--cyan-400);
}

.footer-list--plain li {
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--slate-400);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding-block: 18px clamp(22px, 3vw, 30px);
  border-top: 1px solid var(--ink-800);
  font-size: 12.5px;
  letter-spacing: .05em;
  color: var(--slate-400);
}

.to-top {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 36px;
  padding: 0 16px;
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: .1em;
  color: var(--slate-400);
  background: transparent;
  border: 1px solid var(--ink-700);
  cursor: pointer;
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
  opacity: 0;
  visibility: hidden;
  transition: opacity .25s ease, visibility .25s ease, color .2s ease, border-color .2s ease, background-color .2s ease;
}

.to-top[data-visible] {
  opacity: 1;
  visibility: visible;
}

.to-top:hover {
  color: var(--cyan-400);
  border-color: var(--cyan-400);
  background: rgba(53, 240, 198, .08);
}

.to-top:focus-visible { outline-offset: 3px; }

/* ---------- 15. 显现动效 ---------- */
.js-on [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s var(--ease-out), transform .6s var(--ease-out);
  will-change: opacity, transform;
}

.js-on [data-reveal][data-reveal-in] {
  opacity: 1;
  transform: none;
}

.js-on [data-reveal-delay="1"] { transition-delay: .09s; }
.js-on [data-reveal-delay="2"] { transition-delay: .18s; }
.js-on [data-reveal-delay="3"] { transition-delay: .27s; }

/* ---------- 16. 响应式：头部 ---------- */
@media (max-width: 1080px) {
  .round-chip { display: none; }
}

@media (max-width: 900px) {
  .nav-toggle { display: grid; }

  .header-aside { gap: 8px; }
  .header-cta { display: none; }

  .site-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    display: none;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    padding: 16px var(--gutter) 26px;
    background: var(--ink-900);
    border-top: 1px solid var(--ink-700);
    border-bottom: 1px solid var(--ink-700);
    box-shadow: 0 26px 40px -28px rgba(5, 19, 15, .95);
  }

  .site-nav[data-open] { display: block; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    overflow: visible;
  }

  .nav-list li + li { border-top: 1px solid var(--ink-800); }

  .nav-link {
    justify-content: space-between;
    height: 50px;
    padding: 0 14px;
    border: 0;
    border-radius: 0;
    font-size: 15px;
    letter-spacing: .08em;
  }

  .nav-link::after {
    content: "";
    width: 10px;
    height: 2px;
    background: var(--ink-700);
    transform: skewX(-24deg);
  }

  .nav-link[aria-current="page"]::after { background: var(--ink-950); }

  .nav-extra {
    display: block;
    margin-top: 16px;
  }
}

@media (max-width: 560px) {
  .brand-mark { font-size: 18px; }
  .brand-sub { font-size: 10px; letter-spacing: .12em; }
}

/* ---------- 17. 响应式：页脚 ---------- */
@media (max-width: 1080px) {
  .footer-top { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 520px) {
  .footer-top { grid-template-columns: minmax(0, 1fr); }
  .footer-brand { grid-column: auto; }
  .footer-bottom { justify-content: flex-start; }
}

/* ---------- 18. 降低动效 ---------- */
@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;
  }

  .js-on [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .skip-link { transition: none; }
  .to-top { transition: opacity .001ms linear, visibility .001ms linear; }
}