/* ===========================================================
   千亿球友会 · 全站共享样式 /assets/site.css
   内容：reset / 变量 / 中文排版 / 悬浮胶囊头部 / 页脚 /
        通用按钮 / 面包屑 / 正文容器 / 栅格 / 基础组件
   =========================================================== */

/* ---------- 1. 变量 ---------- */
:root {
  --ink: #0E1B2E;
  --ink-2: #16273F;
  --ink-3: #0b1524;
  --amber: #D9A441;
  --sand: #F0CD8A;
  --celadon: #4FA88B;
  --mist: #A8D8C8;
  --paper: #F5F1E8;
  --text-ink: #1A1A1A;
  --wine: #7A2A34;
  --line: #6B5B45;
  --text-on-dark: #E6E0D3;

  --font-display: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Source Han Sans SC", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: "Songti SC", "Source Han Serif SC", "Noto Serif SC",
    "SimSun", Georgia, "Times New Roman", serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Mono",
    Consolas, "Courier New", monospace;

  --gutter: clamp(1rem, 4vw, 2.5rem);
  --maxw: 1160px;
  --measure: 34em;
  --radius-pill: 999px;
  --radius-card: 16px;
  --shadow-hard: 6px 6px 0 rgba(0, 0, 0, .5);
  --shadow-hard-amber: 8px 8px 0 rgba(217, 164, 65, .28);
  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 2. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  position: relative;
  margin: 0;
  min-height: 100%;
  background: var(--ink);
  color: var(--text-on-dark);
  font-family: var(--font-body);
  font-size: 1.06rem;
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* 黄河石林横向岩层 + 一盏灯 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(0deg, rgba(217, 164, 65, .038) 0 1px, transparent 1px 9px),
    radial-gradient(120% 78% at 78% -6%, rgba(217, 164, 65, .13), transparent 58%),
    radial-gradient(95% 70% at 2% 104%, rgba(79, 168, 139, .09), transparent 62%);
}

img, svg, video { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.22;
  letter-spacing: -0.01em;
  margin: 0 0 .8rem;
}

p { margin: 0 0 1.1rem; }

a {
  color: var(--sand);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
a:hover { color: var(--paper); }

ul, ol { margin: 0 0 1.1rem; padding-left: 1.3rem; }

::selection { background: var(--amber); color: #10161f; }

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

/* ---------- 3. 通用容器与无障碍 ---------- */
.container {
  width: min(var(--maxw), calc(100% - var(--gutter) * 2));
  margin-inline: auto;
}

#main-content {
  position: relative;
  z-index: 1;
  scroll-margin-top: 6rem;
}

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: var(--gutter);
  top: .35rem;
  z-index: 200;
  transform: translateY(-180%);
  background: var(--amber);
  color: #10161f;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: .86rem;
  padding: .6rem 1.15rem;
  border-radius: var(--radius-pill);
  text-decoration: none;
  transition: transform .22s var(--ease);
}
.skip-link:focus { transform: translateY(0); color: #10161f; }

/* ---------- 4. 头部：悬浮胶囊浮岛 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  padding: .85rem 0 .5rem;
  transition: padding .28s var(--ease);
}
.site-header.is-condensed { padding: .42rem 0 .28rem; }

.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: .75rem;
  padding: .45rem .5rem .45rem 1rem;
  background: rgba(22, 39, 63, .88);
  border: 1px solid rgba(217, 164, 65, .32);
  border-radius: var(--radius-pill);
  box-shadow: 0 20px 44px -32px rgba(0, 0, 0, .95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: background .28s var(--ease), border-color .28s var(--ease), padding .28s var(--ease);
}
.site-header.is-condensed .header-inner {
  padding: .25rem .35rem .25rem .8rem;
  background: rgba(11, 21, 36, .96);
  border-color: rgba(217, 164, 65, .6);
}

.brand {
  display: flex;
  align-items: center;
  gap: .65rem;
  flex: 0 0 auto;
  min-width: 0;
  text-decoration: none;
}

.brand-mark {
  flex: none;
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: linear-gradient(150deg, var(--sand), var(--amber) 55%, #a9762a);
  color: #131a24;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.06rem;
  line-height: 1;
  box-shadow: inset 0 -3px 0 rgba(0, 0, 0, .22);
}
.brand-mark--sm {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  font-size: .88rem;
}

.brand-text { display: flex; flex-direction: column; min-width: 0; }

.brand-name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.02rem;
  line-height: 1.15;
  letter-spacing: .06em;
  color: var(--paper);
}

.brand-tag {
  font-family: var(--font-mono);
  font-size: .64rem;
  line-height: 1.4;
  letter-spacing: .26em;
  color: var(--sand);
  opacity: .78;
  white-space: nowrap;
}

/* 导航 */
.site-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: .5rem;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: .1rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  padding: .5rem .72rem;
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: .88rem;
  letter-spacing: .02em;
  color: rgba(245, 241, 232, .76);
  text-decoration: none;
  white-space: nowrap;
  transition: color .2s var(--ease), background-color .2s var(--ease);
}
.nav-link:hover {
  color: var(--paper);
  background: rgba(168, 216, 200, .12);
}
.nav-link[aria-current="page"] {
  color: #131a24;
  background: var(--amber);
  box-shadow: 0 3px 0 -1px rgba(0, 0, 0, .3);
}
.nav-link[aria-current="page"]:hover {
  color: #131a24;
  background: var(--sand);
}

.nav-side {
  display: flex;
  align-items: center;
  gap: .5rem;
  flex: 0 0 auto;
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  border: 1px solid rgba(217, 164, 65, .38);
  border-radius: var(--radius-pill);
  background: rgba(14, 27, 46, .72);
}

.lang-btn {
  border: 0;
  background: transparent;
  color: var(--sand);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: .76rem;
  letter-spacing: .06em;
  padding: .28rem .62rem;
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: background-color .2s var(--ease), color .2s var(--ease);
}
.lang-btn:hover { color: var(--paper); }
.lang-btn[aria-pressed="true"] { background: var(--amber); color: #131a24; }

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: .5rem;
  margin-left: auto;
  padding: .45rem .85rem;
  border: 1px solid rgba(217, 164, 65, .45);
  border-radius: var(--radius-pill);
  background: rgba(217, 164, 65, .12);
  color: var(--sand);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: .82rem;
  cursor: pointer;
}
.nav-toggle-text { letter-spacing: .12em; }

.nav-toggle-bars {
  position: relative;
  display: inline-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 .24s var(--ease), top .24s var(--ease), bottom .24s var(--ease);
}
.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { bottom: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before {
  top: 4px;
  transform: rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after {
  bottom: 4px;
  transform: rotate(-45deg);
}

/* 阅读进度线 */
.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--celadon), var(--amber) 72%, var(--sand));
  transform: scaleX(0);
  transform-origin: 0 50%;
  opacity: .85;
}

/* ---------- 5. 页脚 ---------- */
.site-footer {
  position: relative;
  z-index: 1;
  margin-top: clamp(3rem, 7vw, 6rem);
  background-image:
    repeating-linear-gradient(0deg, rgba(217, 164, 65, .05) 0 1px, transparent 1px 6px),
    linear-gradient(180deg, #101f34, var(--ink) 78%);
  border-top: 2px solid rgba(217, 164, 65, .35);
  color: rgba(245, 241, 232, .76);
  font-family: var(--font-body);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.15fr 1.5fr 1.35fr;
  gap: clamp(1.5rem, 4vw, 3rem);
  padding: clamp(2.5rem, 5vw, 3.75rem) 0 clamp(1.75rem, 3vw, 2.5rem);
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: .6rem;
  margin: 0 0 .4rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.25rem;
  letter-spacing: .05em;
  color: var(--paper);
}

.footer-tag {
  margin: 0 0 .9rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .28em;
  color: var(--sand);
  opacity: .8;
}

.footer-note {
  margin: 0 0 .9rem;
  font-size: .95rem;
  line-height: 1.8;
  color: rgba(245, 241, 232, .68);
  max-width: 30em;
}
.footer-note--small { font-size: .84rem; line-height: 1.75; margin-bottom: 0; }

.footer-status {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  margin: 0;
  padding: .35rem .8rem;
  border: 1px solid rgba(79, 168, 139, .4);
  border-radius: var(--radius-pill);
  background: rgba(79, 168, 139, .1);
  color: var(--mist);
  font-size: .86rem;
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem;
}

.footer-col-title {
  margin: 0 0 .9rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 400;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--amber);
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .5rem;
}

.footer-link {
  display: inline-block;
  padding: .1rem 0;
  color: rgba(245, 241, 232, .76);
  font-size: .98rem;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.footer-link:hover {
  color: var(--sand);
  border-bottom-color: var(--sand);
}

.footer-contact-list {
  list-style: none;
  margin: 0 0 1rem;
  padding: 0;
  display: grid;
  gap: .7rem;
}
.footer-contact-list li { display: grid; gap: .12rem; }

.footer-contact-label {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: rgba(168, 216, 200, .82);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .9rem 2rem;
  padding: 1.4rem 0 2.4rem;
  border-top: 1px solid rgba(217, 164, 65, .2);
}

.footer-signoff {
  flex: 1 1 320px;
  margin: 0;
  padding-left: .9rem;
  border-left: 2px solid var(--amber);
  color: var(--sand);
  font-size: 1rem;
  line-height: 1.75;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem 1.4rem;
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .06em;
  color: rgba(245, 241, 232, .55);
}
.footer-icp { color: rgba(245, 241, 232, .7); }

/* ---------- 6. 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .45rem;
  padding: .7rem 1.25rem;
  border: 2px solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: .92rem;
  letter-spacing: .03em;
  text-decoration: none;
  cursor: pointer;
  transition: transform .2s var(--ease), box-shadow .2s var(--ease),
    background-color .2s var(--ease), border-color .2s var(--ease), color .2s var(--ease);
}

.btn-primary {
  background: var(--amber);
  border-color: var(--amber);
  color: #131a24;
  box-shadow: 0 4px 0 0 rgba(107, 91, 69, .55);
}
.btn-primary:hover {
  background: var(--sand);
  border-color: var(--sand);
  color: #131a24;
  transform: translateY(-2px);
  box-shadow: 0 6px 0 0 rgba(107, 91, 69, .55);
}

.btn-ghost {
  background: transparent;
  border-color: rgba(217, 164, 65, .55);
  color: var(--sand);
}
.btn-ghost:hover {
  background: rgba(217, 164, 65, .12);
  border-color: var(--amber);
  color: var(--paper);
}

.btn-sm { padding: .42rem .9rem; font-size: .82rem; }
.btn-block { width: 100%; }

/* ---------- 7. 面包屑 ---------- */
.breadcrumb { padding: 1.1rem 0 .3rem; }

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .5rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .08em;
  color: rgba(245, 241, 232, .58);
}
.breadcrumb-list li { display: inline-flex; align-items: center; gap: .5rem; }
.breadcrumb-list li + li::before {
  content: "/";
  color: var(--line);
}
.breadcrumb-link { color: var(--sand); text-decoration: none; }
.breadcrumb-link:hover { color: var(--paper); text-decoration: underline; }
.breadcrumb-list [aria-current="page"] { color: var(--paper); }

/* ---------- 8. 章节与正文 ---------- */
.section { padding: clamp(2.6rem, 6vw, 4.5rem) 0; }

.section--indigo { background: var(--ink-2); }

.section--paper {
  background: var(--paper);
  color: var(--text-ink);
  border-top: 2px solid var(--line);
  border-bottom: 2px solid var(--line);
}
.section--paper .section-lede { color: rgba(26, 26, 26, .74); }
.section--paper .kicker { color: var(--wine); }
.section--paper .prose a { color: var(--wine); }
.section--paper .prose a:hover { color: #521a22; }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: clamp(1.4rem, 3vw, 2.2rem);
}

.section-title {
  margin: 0 0 .5rem;
  font-size: clamp(1.7rem, 3.6vw, 2.5rem);
  letter-spacing: -0.015em;
  color: inherit;
}

.section-lede {
  max-width: var(--measure);
  margin: 0;
  font-size: 1.04rem;
  line-height: 1.85;
  color: rgba(230, 224, 211, .74);
}

.kicker {
  display: block;
  margin: 0 0 .5rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .3em;
  text-transform: uppercase;
  color: var(--sand);
}

.lede {
  max-width: var(--measure);
  font-size: 1.16rem;
  line-height: 1.82;
  color: #E9E3D6;
}

.prose {
  max-width: var(--measure);
  font-size: 1.06rem;
  line-height: 1.85;
}
.prose > :last-child { margin-bottom: 0; }

/* ---------- 9. 栅格 ---------- */
.grid {
  display: grid;
  gap: clamp(1rem, 2.4vw, 1.75rem);
}
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-aside { grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr); }

/* ---------- 10. 面板与目录索引块 ---------- */
.panel {
  padding: clamp(1.05rem, 2.4vw, 1.6rem);
  background: var(--ink-2);
  border: 2px solid var(--line);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-hard);
}

.panel--paper {
  background: var(--paper);
  color: var(--text-ink);
  border-color: var(--line);
  box-shadow: 6px 6px 0 rgba(0, 0, 0, .28);
}
.panel--paper a { color: var(--wine); }

.panel--flat { box-shadow: none; }

.panel-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: .5rem 1rem;
  margin-bottom: .85rem;
}

.panel-title {
  margin: 0;
  font-size: 1.15rem;
  letter-spacing: .01em;
  color: inherit;
}

.panel-meta {
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .12em;
  color: var(--amber);
}

.panel-body { font-size: 1rem; line-height: 1.8; }
.panel-body > :last-child { margin-bottom: 0; }

.index-card {
  display: block;
  padding: clamp(1.05rem, 2.4vw, 1.6rem);
  background: var(--ink-2);
  border: 2px solid var(--line);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-hard);
  color: inherit;
  text-decoration: none;
  transition: border-color .24s var(--ease), box-shadow .24s var(--ease), transform .24s var(--ease);
}
.index-card:hover {
  border-color: var(--amber);
  box-shadow: var(--shadow-hard-amber);
  transform: translate(-3px, -3px);
}

.index-no {
  display: block;
  margin-bottom: .5rem;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .18em;
  color: var(--amber);
}

/* ---------- 11. 时间线 ---------- */
.timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 1.6rem;
  list-style: none;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: .45rem;
  bottom: .45rem;
  width: 2px;
  background: linear-gradient(180deg, var(--line), rgba(107, 91, 69, .12));
}

.timeline-item {
  position: relative;
  padding-bottom: 1.6rem;
}
.timeline-item:last-child { padding-bottom: 0; }

.timeline-item::before {
  content: "";
  position: absolute;
  left: -1.6rem;
  top: .5rem;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--line);
  transition: background-color .24s var(--ease), border-color .24s var(--ease);
}
.timeline-item[data-state="new"]::before {
  background: var(--celadon);
  border-color: var(--mist);
  box-shadow: 0 0 0 4px rgba(79, 168, 139, .18);
}

.timeline-meta {
  display: block;
  margin-bottom: .3rem;
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .12em;
  color: var(--amber);
}

/* ---------- 12. 可展开内容组 ---------- */
.accordion { border-top: 1px solid rgba(217, 164, 65, .22); }

.accordion-item { border-bottom: 1px solid rgba(217, 164, 65, .22); }

.accordion-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.1rem .2rem;
  border: 0;
  background: transparent;
  color: inherit;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  line-height: 1.5;
  text-align: left;
  cursor: pointer;
}
.accordion-trigger::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 1.3rem;
  line-height: 1;
  color: var(--amber);
  transition: transform .24s var(--ease);
}
.accordion-trigger[aria-expanded="true"]::after {
  content: "–";
  transform: rotate(180deg);
}

.accordion-panel {
  overflow: hidden;
  transition: height .28s var(--ease);
}
.accordion-inner {
  padding: 0 .2rem 1.25rem;
  font-size: 1rem;
  line-height: 1.85;
}
.accordion-inner > :last-child { margin-bottom: 0; }

/* ---------- 13. 状态与标记 ---------- */
.status-dot {
  flex: none;
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--celadon);
  box-shadow: 0 0 0 3px rgba(79, 168, 139, .24);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .22rem .62rem;
  border: 1px solid rgba(168, 216, 200, .3);
  border-radius: var(--radius-pill);
  background: rgba(168, 216, 200, .13);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.tag--amber {
  border-color: rgba(217, 164, 65, .38);
  background: rgba(217, 164, 65, .15);
  color: var(--sand);
}
.tag--wine {
  border-color: rgba(122, 42, 52, .75);
  background: rgba(122, 42, 52, .35);
  color: #EBBCC1;
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .08em;
  color: var(--amber);
}

/* ---------- 14. 图片容器（供页面阶段放置图片） ---------- */
.img-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 2px solid var(--line);
  border-radius: var(--radius-card);
  background: linear-gradient(150deg, var(--ink-2), var(--ink-3));
}
.img-frame img,
.img-frame svg,
.img-frame picture {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(0deg, rgba(217, 164, 65, .07) 0 1px, transparent 1px 7px),
    radial-gradient(120% 90% at 72% 12%, rgba(217, 164, 65, .18), transparent 62%);
}

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

.img-caption {
  margin: .6rem 0 0;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .08em;
  line-height: 1.7;
  color: rgba(230, 224, 211, .6);
}

/* ---------- 15. 入场显现协议 ---------- */
[data-reveal].is-reveal-pending {
  opacity: 0;
  transform: translateY(14px);
}
[data-reveal].is-visible {
  opacity: 1;
  transform: none;
  transition: opacity .32s var(--ease), transform .32s var(--ease);
}

/* ---------- 16. 响应式 ---------- */
@media (max-width: 1000px) {
  .nav-toggle { display: inline-flex; }

  .site-nav {
    position: absolute;
    top: calc(100% + .5rem);
    left: var(--gutter);
    right: var(--gutter);
    margin-left: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: .6rem;
    border: 1px solid rgba(217, 164, 65, .38);
    border-radius: 22px;
    background: rgba(11, 21, 36, .98);
    box-shadow: 0 30px 60px -30px #000;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity .24s var(--ease), transform .24s var(--ease), visibility .24s linear;
  }
  .site-nav[data-open="true"] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: .1rem;
    width: 100%;
  }
  .nav-link {
    width: 100%;
    justify-content: flex-start;
    padding: .8rem .9rem;
    border-radius: 14px;
    font-size: 1rem;
  }

  .nav-side {
    margin-top: .5rem;
    padding: .65rem .5rem .2rem;
    border-top: 1px solid rgba(217, 164, 65, .22);
    justify-content: space-between;
  }

  .grid-2,
  .grid-3,
  .grid-aside { grid-template-columns: 1fr; }
}

@media (max-width: 980px) {
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 720px) {
  body { font-size: 1rem; }
  .footer-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-bottom { padding-bottom: 2rem; }
}

@media (max-width: 560px) {
  .brand-tag { display: none; }
  .brand-mark { width: 34px; height: 34px; border-radius: 10px; font-size: .94rem; }
  .brand-name { font-size: .96rem; }
  .header-inner { padding: .4rem .4rem .4rem .8rem; }
  .nav-toggle { padding: .4rem .7rem; }
  .lang-btn { padding: .26rem .5rem; font-size: .72rem; }
  .grid-2, .grid-3, .grid-aside { gap: 1rem; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-nav { grid-template-columns: 1fr; }
}

/* ---------- 17. 无障碍动作偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  [data-reveal].is-reveal-pending {
    opacity: 1 !important;
    transform: none !important;
  }
}