/* =========================================================
   立即博赛场 — 共享样式表 /assets/site.css
   深夜绿茵场 · 框架式导航 · 等高线纹理
   ========================================================= */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 120px;
}

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

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

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

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

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

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

/* ---------- 2. 设计变量 ---------- */
:root {
  --ink-green: #0B1F1A;
  --green-2: #123A31;
  --green-3: #18453A;
  --cyan: #2FF3C8;
  --amber: #F2A63B;
  --violet: #8A5CF6;
  --gold: #D9C37A;
  --paper: #F4EDE1;
  --paper-2: #E5D9C4;
  --bone: #FFFDF7;
  --karst: #7C8A86;
  --ink: #0A0C0B;

  --cyan-deep: #0B7A65;
  --amber-deep: #A3651A;
  --violet-deep: #5B36B0;

  --font-sans: "Source Han Sans SC", "Noto Sans SC", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Heiti SC", system-ui, -apple-system,
    "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", "SFMono-Regular", Menlo,
    Consolas, "Courier New", monospace;

  --shell: 1260px;
  --gutter: clamp(18px, 4vw, 56px);
  --radius-l: 26px 6px 26px 6px;
  --radius-m: 14px 4px 14px 4px;
  --hair: rgba(124, 138, 134, 0.34);
  --hair-soft: rgba(124, 138, 134, 0.2);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --head-h: 88px;
}

/* ---------- 3. 中文基础排版 ---------- */
body {
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 500;
  line-height: 1.75;
  letter-spacing: 0.012em;
  color: var(--bone);
  background: var(--ink-green);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

h1 { font-size: clamp(40px, 7vw, 96px); }
h2 { font-size: clamp(26px, 3.4vw, 44px); }
h3 { font-size: clamp(20px, 2.2vw, 27px); }
h4 { font-size: 18px; letter-spacing: -0.01em; }

p { max-width: 72ch; }

strong, b { font-weight: 800; }

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

code, kbd, samp, .num, .data-figure {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

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

/* ---------- 4. 布局容器 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.band {
  position: relative;
  padding-block: clamp(48px, 7vw, 100px);
}

.band--deep { background: var(--ink-green); color: var(--bone); }
.band--layered { background: var(--green-2); color: var(--bone); }
.band--ink { background: var(--ink); color: var(--bone); }
.band--paper { background: var(--paper); color: var(--ink); }
.band--edge {
  border-top: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(18px, 2.6vw, 40px);
}

.col-main { grid-column: span 7; }
.col-side { grid-column: span 5; }

.split {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: clamp(26px, 4vw, 62px);
  align-items: start;
}

.split__side {
  position: sticky;
  top: 118px;
}

.prose {
  max-width: 66ch;
  font-size: 17px;
  line-height: 1.8;
}

.prose > * + * { margin-top: 1.1em; }
.prose h2 { margin-top: 1.8em; font-size: clamp(24px, 2.6vw, 32px); }
.prose h3 { margin-top: 1.5em; }
.prose ul, .prose ol { padding-left: 1.15em; }
.prose ul li { list-style: none; position: relative; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: -1.05em;
  top: 0.72em;
  width: 7px;
  height: 2px;
  background: var(--cyan);
}
.prose ol { list-style: decimal; }
.prose li + li { margin-top: 0.5em; }

.stack-sm > * + * { margin-top: 12px; }
.stack-md > * + * { margin-top: 24px; }

.rule {
  height: 1px;
  border: 0;
  background: var(--hair);
}

/* ---------- 5. 文字组件 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--karst);
}

.eyebrow::before {
  content: "";
  width: 24px;
  height: 1px;
  background: currentColor;
  flex: none;
}

.band--paper .eyebrow { color: var(--cyan-deep); }

.section-no {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--karst);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  border: 1px solid currentColor;
  border-radius: 2px;
  line-height: 1.5;
  white-space: nowrap;
}

.tag--amber { color: var(--amber); background: rgba(242, 166, 59, 0.13); }
.tag--cyan { color: var(--cyan); background: rgba(47, 243, 200, 0.1); }
.tag--violet { color: var(--violet); background: rgba(138, 92, 246, 0.15); }
.tag--gold { color: var(--gold); background: rgba(217, 195, 122, 0.13); }
.tag--karst { color: var(--karst); background: rgba(124, 138, 134, 0.12); }

.figure {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.figure__value {
  font-family: var(--font-mono);
  font-size: clamp(30px, 4vw, 46px);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--cyan);
}

.figure__unit {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--karst);
}

.band--paper .figure__value { color: var(--cyan-deep); }

/* ---------- 6. 按钮 ---------- */
.btn {
  --btn-bg: var(--cyan);
  --btn-fg: var(--ink-green);
  --btn-bd: var(--cyan);
  --btn-ring: rgba(47, 243, 200, 0.24);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.04em;
  line-height: 1.4;
  color: var(--btn-fg);
  background: var(--btn-bg);
  border: 1px solid var(--btn-bd);
  border-radius: 2px 14px 2px 14px;
  cursor: pointer;
  text-align: center;
  transition: box-shadow 0.2s var(--ease), background-color 0.2s var(--ease),
    color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.btn:hover { box-shadow: 0 0 0 3px var(--btn-ring); }
.btn:active { box-shadow: 0 0 0 1px var(--btn-ring); }

.btn--signal {
  --btn-bg: var(--cyan);
  --btn-fg: var(--ink-green);
  --btn-bd: var(--cyan);
  --btn-ring: rgba(47, 243, 200, 0.26);
}

.btn--amber {
  --btn-bg: var(--amber);
  --btn-fg: var(--ink);
  --btn-bd: var(--amber);
  --btn-ring: rgba(242, 166, 59, 0.3);
}

.btn--violet {
  --btn-bg: var(--violet);
  --btn-fg: var(--bone);
  --btn-bd: var(--violet);
  --btn-ring: rgba(138, 92, 246, 0.32);
}

.btn--ghost {
  --btn-bg: transparent;
  --btn-fg: var(--cyan);
  --btn-bd: rgba(47, 243, 200, 0.6);
  --btn-ring: rgba(47, 243, 200, 0.22);
}

.btn--ghost:hover { --btn-bg: rgba(47, 243, 200, 0.1); }

.btn--paper {
  --btn-bg: transparent;
  --btn-fg: var(--ink);
  --btn-bd: rgba(10, 12, 11, 0.35);
  --btn-ring: rgba(11, 122, 101, 0.22);
}

.btn--paper:hover {
  --btn-bg: var(--ink);
  --btn-fg: var(--bone);
  --btn-bd: var(--ink);
}

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

/* ---------- 7. 内容块 ---------- */
.panel {
  position: relative;
  padding: clamp(20px, 2.6vw, 32px);
  background: var(--green-2);
  border: 1px solid var(--hair);
  border-radius: var(--radius-l);
}

.panel--paper {
  background: var(--paper);
  color: var(--ink);
  border-color: rgba(10, 12, 11, 0.14);
}

.panel--bone {
  background: var(--bone);
  color: var(--ink);
  border-color: rgba(10, 12, 11, 0.12);
}

.panel--quiet {
  background: rgba(18, 58, 49, 0.55);
  border-style: dashed;
}

/* ---------- 8. 图片容器 ---------- */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  border: 1px solid var(--hair);
  border-radius: var(--radius-m);
  background: linear-gradient(142deg, var(--green-2) 0%, var(--ink-green) 100%);
}

.band--paper .media-frame,
.media-frame--paper {
  background: linear-gradient(142deg, var(--paper-2) 0%, var(--paper) 100%);
  border-color: rgba(10, 12, 11, 0.14);
}

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

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame__cap {
  position: absolute;
  inset: auto 0 0 0;
  padding: 22px 14px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--bone);
  background: linear-gradient(0deg, rgba(11, 31, 26, 0.92), rgba(11, 31, 26, 0));
}

/* ---------- 9. 等高线纹理 ---------- */
.contour {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-radial-gradient(circle at 8% 112%,
      transparent 0 44px, rgba(124, 138, 134, 0.18) 44px 45px),
    repeating-radial-gradient(circle at 96% -8%,
      transparent 0 36px, rgba(124, 138, 134, 0.14) 36px 37px);
}

.band--paper .contour {
  background-image:
    repeating-radial-gradient(circle at 8% 112%,
      transparent 0 44px, rgba(11, 31, 26, 0.09) 44px 45px),
    repeating-radial-gradient(circle at 96% -8%,
      transparent 0 36px, rgba(11, 31, 26, 0.07) 36px 37px);
}

/* ---------- 10. 面包屑 ---------- */
.breadcrumb {
  padding-block: 16px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--karst);
}

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

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

.breadcrumb li + li::before {
  content: "/";
  opacity: 0.55;
}

.breadcrumb a:hover { color: var(--cyan); }
.breadcrumb [aria-current="page"] { color: var(--bone); }

.breadcrumb--paper { color: rgba(10, 12, 11, 0.55); }
.breadcrumb--paper a:hover { color: var(--cyan-deep); }
.breadcrumb--paper [aria-current="page"] { color: var(--ink); }

/* ---------- 11. 折叠组 ---------- */
.disclosure { border-top: 1px dashed var(--hair); }
.disclosure:last-of-type { border-bottom: 1px dashed var(--hair); }

.disclosure__trigger {
  display: flex;
  width: 100%;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 2px;
  text-align: left;
  font-size: 17px;
  font-weight: 800;
  letter-spacing: -0.01em;
  cursor: pointer;
  color: inherit;
}

.disclosure__trigger:hover { color: var(--cyan); }
.band--paper .disclosure__trigger:hover { color: var(--cyan-deep); }

.disclosure__icon {
  flex: none;
  position: relative;
  width: 22px;
  height: 22px;
  margin-top: 3px;
  border: 1px solid currentColor;
  border-radius: 50%;
  transition: transform 0.25s var(--ease);
}

.disclosure__icon::before,
.disclosure__icon::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: currentColor;
  transform: translate(-50%, -50%);
}

.disclosure__icon::before { width: 10px; height: 1.5px; }
.disclosure__icon::after { width: 1.5px; height: 10px; }

.disclosure__trigger[aria-expanded="true"] .disclosure__icon { transform: rotate(180deg); }
.disclosure__trigger[aria-expanded="true"] .disclosure__icon::after { opacity: 0; }

.disclosure__body {
  padding: 0 34px 22px 2px;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(255, 253, 247, 0.78);
}

.band--paper .disclosure__body { color: rgba(10, 12, 11, 0.74); }
.disclosure__body[hidden] { display: none; }

/* ---------- 12. 显现动画 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.55s var(--ease), transform 0.55s var(--ease);
}

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

/* ---------- 13. 共享头部 ---------- */
.skip-link {
  position: absolute;
  left: 14px;
  top: -70px;
  z-index: 200;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 800;
  color: var(--ink-green);
  background: var(--cyan);
  border-radius: 2px 12px 2px 12px;
  transition: top 0.18s var(--ease);
}

.skip-link:focus { top: 12px; }

.site-frame {
  position: sticky;
  top: 0;
  z-index: 90;
  background: var(--ink-green);
  border-bottom: 1px solid var(--hair);
  box-shadow: 0 20px 44px -38px rgba(0, 0, 0, 0.95);
}

.frame-rail {
  position: absolute;
  inset: 0 0 auto 0;
  height: 5px;
  opacity: 0.72;
  background-image:
    repeating-linear-gradient(90deg, rgba(47, 243, 200, 0.95) 0 2px, transparent 2px 18px),
    linear-gradient(90deg, var(--cyan) 0%, var(--violet) 42%, var(--amber) 100%);
}

.frame-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(16px, 3vw, 44px);
  width: 100%;
  max-width: var(--shell);
  min-height: var(--head-h);
  margin-inline: auto;
  padding: 14px var(--gutter);
}

.brand {
  position: relative;
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  padding-left: 14px;
  line-height: 1.1;
}

.brand::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1px;
  bottom: 1px;
  width: 4px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--amber) 100%);
}

.brand__mark {
  font-size: clamp(18px, 2.1vw, 22px);
  font-weight: 900;
  letter-spacing: 0.06em;
  color: var(--bone);
}

.brand__tag {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--karst);
  white-space: nowrap;
}

.frame-nav {
  min-width: 0;
}

.frame-nav__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: clamp(10px, 1.8vw, 26px);
  justify-content: center;
}

.frame-nav__link {
  position: relative;
  display: inline-block;
  padding: 6px 2px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: rgba(255, 253, 247, 0.76);
  transition: color 0.2s var(--ease);
  white-space: nowrap;
}

.frame-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.22s var(--ease);
}

.frame-nav__link:hover { color: var(--bone); }
.frame-nav__link:hover::after { transform: scaleX(1); }

.frame-nav__link[aria-current="page"] { color: var(--cyan); }
.frame-nav__link[aria-current="page"]::after { transform: scaleX(1); }

.frame-nav__foot { display: none; }

.frame-head__side {
  display: flex;
  align-items: center;
  gap: 14px;
}

.util-link {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--karst);
  padding-block: 4px;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.util-link:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--cyan);
  border: 1px solid rgba(47, 243, 200, 0.5);
  border-radius: 2px 12px 2px 12px;
  cursor: pointer;
  transition: background-color 0.2s var(--ease);
}

.nav-toggle:hover { background: rgba(47, 243, 200, 0.1); }

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  box-shadow: 0 -5px 0 currentColor, 0 5px 0 currentColor;
  transition: background-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars {
  background: transparent;
  box-shadow: none;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before,
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after {
  content: "";
  position: absolute;
  inset: 0;
  background: currentColor;
}

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

.frame-progress {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--violet) 100%);
}

/* ---------- 14. 共享页脚 ---------- */
.site-foot {
  position: relative;
  overflow: hidden;
  color: var(--bone);
  background: linear-gradient(180deg, var(--green-2) 0%, var(--ink-green) 62%);
  border-top: 1px solid var(--hair);
}

.foot-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 0.85fr) 1.25fr;
  gap: clamp(24px, 3vw, 46px);
  padding-block: clamp(44px, 6vw, 78px) clamp(26px, 4vw, 46px);
}

.foot-brand {
  display: flex;
  flex-direction: column;
  gap: 18px;
  max-width: 34ch;
}

.brand--foot .brand__mark { font-size: 22px; }

.foot-note {
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(255, 253, 247, 0.68);
  max-width: 32ch;
}

.foot-col__title,
.foot-contact .foot-col__title {
  padding-bottom: 10px;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan);
  border-bottom: 1px solid var(--hair);
}

.foot-col:nth-of-type(1) .foot-col__title { color: var(--cyan); }
.foot-col:nth-of-type(2) .foot-col__title { color: var(--amber); }
.foot-col:nth-of-type(3) .foot-col__title { color: var(--gold); }

.foot-col__list {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.foot-col__list a {
  display: inline-block;
  font-size: 14.5px;
  color: rgba(255, 253, 247, 0.78);
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.foot-col__list a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.foot-contact__list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.foot-contact__item {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.foot-contact__key {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--karst);
}

.foot-contact__val {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(255, 253, 247, 0.86);
  word-break: break-word;
}

.foot-base {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 26px;
  padding-block: 18px 28px;
  border-top: 1px solid var(--hair-soft);
}

.foot-base__line {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--karst);
  max-width: none;
}

/* ---------- 15. 响应式 ---------- */
@media (max-width: 1080px) {
  .foot-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .foot-brand { max-width: none; }
}

@media (max-width: 960px) {
  .split { grid-template-columns: minmax(0, 1fr); }
  .split__side { position: static; top: auto; }
  .col-main, .col-side { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  :root { --head-h: 74px; }

  .frame-head {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 14px;
    padding-block: 12px;
  }

  .frame-head__side .btn--signal { display: none; }
  .nav-toggle { display: inline-flex; }

  .frame-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: block;
    padding: 16px var(--gutter) 26px;
    background: var(--green-2);
    border-bottom: 1px solid var(--hair);
    max-height: calc(100vh - 90px);
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity 0.2s var(--ease), transform 0.2s var(--ease),
      visibility 0.2s var(--ease);
  }

  .frame-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .frame-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    justify-content: flex-start;
  }

  .frame-nav__link {
    display: block;
    padding: 14px 4px;
    font-size: 17px;
    border-bottom: 1px dashed var(--hair-soft);
  }

  .frame-nav__link::after { display: none; }
  .frame-nav__link[aria-current="page"] { padding-left: 14px; }

  .frame-nav__link[aria-current="page"]::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    width: 5px;
    height: 5px;
    margin-top: -2.5px;
    background: var(--cyan);
    border-radius: 50%;
  }

  .frame-nav__foot {
    display: flex;
    flex-direction: column;
    gap: 14px;
    margin-top: 22px;
  }

  .frame-nav__foot .util-link { letter-spacing: 0.12em; }
}

@media (max-width: 640px) {
  body { font-size: 16.5px; }
  .grid-12 { gap: 16px; }
  .foot-grid { grid-template-columns: minmax(0, 1fr); }
  .foot-base { justify-content: flex-start; }
  .media-frame { aspect-ratio: 4 / 3; }
  .media-frame--wide { aspect-ratio: 16 / 9; }
}

/* ---------- 16. 可访问性与动效偏好 ---------- */
@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;
    transition-delay: 0ms !important;
  }

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