/* ============================================================
   澳门娱乐汇 / 全站共享样式  /assets/site.css
   母题：霓虹夜色 × 葡式砖纹 × -6° 切面
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root{
  --ink-0:#0A0F2C;
  --ink-1:#141C4A;
  --ink-2:#1B2559;
  --mist:#F2F5FC;
  --paper:#FFFFFF;
  --cobalt:#2B4BD8;
  --mint:#3FD6B0;
  --mint-deep:#1C8C74;
  --gold:#FFC24A;
  --coral:#FF6B4A;
  --beige:#E7DFCB;
  --slate:#8C93B8;

  --hairline:rgba(231,223,203,.16);
  --hairline-strong:rgba(231,223,203,.34);

  --font-display:"Archivo Black","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"IBM Plex Mono","Sarasa Mono SC",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --shell:1240px;
  --gutter:clamp(1.15rem,4vw,3.5rem);
  --header-h:76px;

  --dur:200ms;
  --dur-fast:120ms;
  --ease:cubic-bezier(.2,.7,.2,1);

  --skew:-6deg;
  --cut:polygon(0 0,calc(100% - 18px) 0,100% 18px,100% 100%,0 100%);
  --cut-sm:polygon(0 0,calc(100% - 10px) 0,100% 10px,100% 100%,0 100%);
}

/* ---------- 2. reset & base ---------- */
*,
*::before,
*::after{ box-sizing:border-box; }

html{
  -webkit-text-size-adjust:100%;
  text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--header-h) + 20px);
}

body{
  margin:0;
  background:var(--ink-0);
  color:var(--mist);
  font-family:var(--font-body);
  font-size:1rem;
  line-height:1.85;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
}

body.is-nav-open{ overflow:hidden; }

h1,h2,h3,h4,p,figure,blockquote{ margin:0; }
ul,ol{ margin:0; padding:0; list-style:none; }
img,svg{ display:block; max-width:100%; }
a{ color:inherit; }
button{ font:inherit; color:inherit; }

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

::selection{ background:var(--mint); color:var(--ink-0); }

.skip-link{
  position:fixed;
  top:.5rem;
  left:50%;
  z-index:999;
  transform:translate(-50%,-160%);
  padding:.7rem 1.4rem;
  background:var(--gold);
  color:var(--ink-0);
  font-family:var(--font-body);
  font-size:.875rem;
  font-weight:700;
  letter-spacing:.08em;
  text-decoration:none;
  clip-path:var(--cut-sm);
  transition:transform var(--dur) var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible{ transform:translate(-50%,0); }

/* ---------- 3. 排版工具 ---------- */
.display{
  font-family:var(--font-display);
  font-weight:900;
  font-size:clamp(2.4rem,6vw,5.4rem);
  line-height:1.05;
  letter-spacing:-.02em;
  margin:0;
}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:.6rem;
  margin:0 0 1rem;
  font-family:var(--font-mono);
  font-size:.6875rem;
  font-weight:500;
  letter-spacing:.24em;
  text-transform:uppercase;
  color:var(--slate);
}
.eyebrow::before{
  content:"";
  width:22px;
  height:2px;
  background:var(--gold);
  transform:skewX(-30deg);
}

.lede{
  max-width:62ch;
  font-size:clamp(1rem,1.4vw,1.125rem);
  line-height:1.85;
  color:rgba(242,245,252,.82);
}

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

.section{
  padding-block:clamp(3rem,8vw,6.5rem);
}

.section--ink{
  background:var(--ink-0);
  color:var(--mist);
}

.section--light{
  background:var(--mist);
  color:var(--ink-0);
  --hairline:rgba(10,15,44,.14);
  --hairline-strong:rgba(10,15,44,.3);
}
.section--light .lede{ color:rgba(10,15,44,.78); }
.section--light .eyebrow{ color:var(--mint-deep); }

/* ---------- 5. 通用按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.5rem;
  min-height:48px;
  padding:.75rem 1.5rem;
  border:1px solid transparent;
  background:transparent;
  color:var(--mist);
  font-family:var(--font-body);
  font-size:.9375rem;
  font-weight:600;
  letter-spacing:.06em;
  text-decoration:none;
  cursor:pointer;
  clip-path:polygon(0 0,calc(100% - 12px) 0,100% 12px,100% 100%,12px 100%,0 calc(100% - 12px));
  transition:background var(--dur) var(--ease),color var(--dur) var(--ease),
             transform var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.btn--gold{ background:var(--gold); color:var(--ink-0); }
.btn--gold:hover{ background:#ffd16f; transform:translateY(-2px); }
.btn--ghost{ border-color:var(--hairline-strong); color:var(--mist); }
.btn--ghost:hover{ border-color:var(--mint); color:var(--mint); }

/* ---------- 6. 面包屑 ---------- */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.55rem;
  margin-bottom:1.5rem;
  font-family:var(--font-mono);
  font-size:.6875rem;
  letter-spacing:.14em;
  color:var(--slate);
}
.breadcrumb a{ text-decoration:none; color:inherit; }
.breadcrumb a:hover{ color:var(--gold); }
.breadcrumb__sep{ color:rgba(140,147,184,.55); }
.breadcrumb [aria-current]{ color:var(--mist); }
.section--light .breadcrumb [aria-current]{ color:var(--ink-0); }

/* ---------- 7. 图片容器 ---------- */
.media-frame{
  position:relative;
  display:block;
  overflow:hidden;
  aspect-ratio:4 / 3;
  background:
    radial-gradient(120% 120% at 20% 0%,rgba(43,75,216,.55),transparent 62%),
    linear-gradient(160deg,var(--ink-2),var(--ink-0) 70%);
  clip-path:polygon(0 0,calc(100% - 28px) 0,100% 28px,100% 100%,0 100%);
}
.media-frame > img,
.media-frame > svg{
  width:100%;
  height:100%;
  object-fit:cover;
}
.media-frame--wide{ aspect-ratio:16 / 9; }
.media-frame--tall{ aspect-ratio:3 / 4; }
.media-frame__caption{
  position:absolute;
  left:0;
  bottom:0;
  padding:.55rem .9rem;
  background:rgba(10,15,44,.84);
  color:var(--mist);
  font-family:var(--font-mono);
  font-size:.6875rem;
  letter-spacing:.14em;
}

/* ---------- 8. 规则索引列表 ---------- */
.rule-list{
  display:grid;
  border-top:1px solid var(--hairline);
}
.rule-item{
  display:grid;
  grid-template-columns:auto 1fr auto;
  gap:.4rem 1.1rem;
  align-items:baseline;
  padding:1rem 0;
  border-bottom:1px solid var(--hairline);
  transition:background var(--dur) var(--ease),padding-left var(--dur) var(--ease);
}
.rule-item:hover{ padding-left:.6rem; background:rgba(43,75,216,.08); }
.rule-item__num{
  font-family:var(--font-mono);
  font-size:.8125rem;
  letter-spacing:.1em;
  color:var(--mint-deep);
}

/* ---------- 9. 标签 ---------- */
.tag{
  display:inline-flex;
  align-items:center;
  gap:.4rem;
  min-height:40px;
  padding:.4rem 1rem;
  border:1px solid var(--hairline-strong);
  background:rgba(20,28,74,.55);
  color:var(--mist);
  font-size:.875rem;
  letter-spacing:.04em;
  text-decoration:none;
  cursor:pointer;
  clip-path:var(--cut-sm);
  transition:background var(--dur-fast) var(--ease),color var(--dur-fast) var(--ease),
             transform var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease);
}
.tag:hover{ border-color:var(--mint); color:var(--mint); }
.tag--active,
.tag[aria-pressed="true"]{
  background:var(--mint);
  border-color:var(--mint);
  color:var(--ink-0);
  transform:scale(.98);
}

/* ---------- 10. 卡片 ---------- */
.card{
  position:relative;
  display:block;
  padding:clamp(1.25rem,2.5vw,1.9rem);
  background:var(--ink-1);
  color:var(--mist);
  clip-path:var(--cut);
  border:1px solid var(--hairline);
  transition:transform var(--dur) var(--ease),background var(--dur) var(--ease);
}
.card:hover{ transform:translateY(-4px); background:var(--ink-2); }

/* ---------- 11. 章节索引 ---------- */
.toc-link{
  display:flex;
  align-items:baseline;
  gap:.65rem;
  padding:.45rem 0;
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.12em;
  color:var(--slate);
  text-decoration:none;
  transition:color var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.toc-link:hover{ color:var(--mist); transform:translateX(3px); }
.toc-link[aria-current]{ color:var(--gold); }

/* ============================================================
   12. 页头
   ============================================================ */
.site-header{
  position:sticky;
  top:0;
  z-index:120;
  color:var(--mist);
  background:
    radial-gradient(120% 220% at 6% -70%,rgba(43,75,216,.55),transparent 58%),
    radial-gradient(80% 180% at 96% -90%,rgba(63,214,176,.22),transparent 60%),
    linear-gradient(180deg,rgba(10,15,44,.97),rgba(10,15,44,.91));
  -webkit-backdrop-filter:blur(16px) saturate(125%);
  backdrop-filter:blur(16px) saturate(125%);
  box-shadow:inset 0 -1px 0 var(--hairline),0 18px 40px -28px rgba(0,0,0,.95);
}

.progress-bar{
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  height:2px;
  background:rgba(140,147,184,.2);
  overflow:hidden;
  z-index:2;
}
.progress-bar__fill{
  display:block;
  width:100%;
  height:100%;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--mint-deep),var(--mint) 45%,var(--gold));
  transition:transform .1s linear;
}

.header-inner{
  position:relative;
  display:flex;
  align-items:center;
  gap:clamp(.75rem,2vw,2rem);
  width:100%;
  max-width:var(--shell);
  min-height:var(--header-h);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

/* 品牌 */
.brand{
  display:inline-flex;
  align-items:center;
  gap:.75rem;
  flex:0 0 auto;
  color:inherit;
  text-decoration:none;
}
.brand__mark{
  display:grid;
  place-items:center;
  width:38px;
  height:38px;
  background:linear-gradient(150deg,var(--gold) 8%,var(--coral) 92%);
  color:var(--ink-0);
  font-family:var(--font-display);
  font-size:1.0625rem;
  font-weight:900;
  line-height:1;
  transform:skewX(-6deg);
  transition:transform var(--dur) var(--ease);
}
.brand__mark > span{ display:block; transform:skewX(6deg); }
.brand:hover .brand__mark{ transform:skewX(-6deg) scale(1.06); }

.brand__type{ display:flex; flex-direction:column; gap:2px; }
.brand__name{
  font-family:var(--font-display);
  font-size:1.0625rem;
  font-weight:900;
  letter-spacing:.06em;
  line-height:1.2;
  color:var(--mist);
}
.brand__tagline{
  font-family:var(--font-mono);
  font-size:.625rem;
  letter-spacing:.2em;
  line-height:1;
  color:var(--slate);
}

/* 中段章节 */
.header-chapter{
  display:flex;
  align-items:center;
  justify-content:center;
  gap:.65rem;
  flex:1 1 auto;
  min-width:0;
  overflow:hidden;
  margin:0;
  font-family:var(--font-mono);
  font-size:.6875rem;
  letter-spacing:.18em;
  white-space:nowrap;
}
.header-chapter__num{ color:var(--gold); }
.header-chapter__rule{
  display:block;
  width:26px;
  height:1px;
  background:linear-gradient(90deg,var(--gold),rgba(255,194,74,0));
  transform:skewX(-30deg);
}
.header-chapter__name{ color:var(--slate); }

/* 主导航 */
.site-nav{
  display:flex;
  align-items:center;
  flex:0 0 auto;
  margin-left:auto;
}
.nav-list{
  display:flex;
  align-items:center;
  gap:2px;
}
.nav-link{
  position:relative;
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:.5rem clamp(.45rem,1vw,.7rem);
  font-size:clamp(.8125rem,1.05vw,.875rem);
  letter-spacing:.05em;
  color:rgba(242,245,252,.78);
  text-decoration:none;
  isolation:isolate;
  transition:color var(--dur) var(--ease);
}
.nav-link::before{
  content:"";
  position:absolute;
  inset:7px 2px;
  z-index:-1;
  background:linear-gradient(100deg,rgba(43,75,216,.6),rgba(63,214,176,.24));
  transform:skewX(-6deg) scaleX(.55);
  opacity:0;
  transition:opacity var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.nav-link:hover{ color:var(--mist); }
.nav-link:hover::before{ opacity:1; transform:skewX(-6deg) scaleX(1); }

.nav-link[aria-current="page"]{
  color:var(--gold);
  font-weight:700;
}
.nav-link[aria-current="page"]::before{
  opacity:1;
  transform:skewX(-6deg) scaleX(1);
  background:linear-gradient(100deg,rgba(255,194,74,.24),rgba(255,194,74,.04));
}
.nav-link[aria-current="page"]::after{
  content:"";
  position:absolute;
  left:8px;
  right:8px;
  bottom:5px;
  height:2px;
  background:var(--gold);
  transform:skewX(-30deg);
}

/* 移动面板内的版本回显，桌面隐藏 */
.nav-meta{ display:none; }

/* 右侧工具区 */
.header-tools{
  display:flex;
  align-items:center;
  gap:.6rem;
  flex:0 0 auto;
}

/* 版本切换 */
.version-switch{
  position:relative;
  display:inline-grid;
  grid-auto-flow:column;
  grid-auto-columns:1fr;
  align-items:center;
  padding:3px;
  background:rgba(10,15,44,.72);
  border:1px solid var(--hairline-strong);
  clip-path:polygon(10px 0,100% 0,100% calc(100% - 10px),calc(100% - 10px) 100%,0 100%,0 10px);
  isolation:isolate;
}
.version-switch__thumb{
  position:absolute;
  top:3px;
  bottom:3px;
  left:3px;
  width:calc(50% - 3px);
  z-index:0;
  background:linear-gradient(140deg,var(--gold),#ffd98a);
  clip-path:polygon(6px 0,100% 0,100% calc(100% - 6px),calc(100% - 6px) 100%,0 100%,0 6px);
  transition:transform var(--dur) var(--ease);
}
.version-switch[data-version="old"] .version-switch__thumb{ transform:translateX(100%); }

.version-switch__btn{
  position:relative;
  z-index:1;
  appearance:none;
  border:0;
  background:transparent;
  cursor:pointer;
  min-width:56px;
  min-height:40px;
  padding:0 .6rem;
  font-family:var(--font-body);
  font-size:.8125rem;
  font-weight:600;
  letter-spacing:.08em;
  color:rgba(242,245,252,.72);
  transition:color var(--dur) var(--ease);
}
.version-switch__btn.is-active{ color:var(--ink-0); }
.version-switch__btn[data-version-option="old"].is-active{ color:var(--ink-0); }

/* 移动导航按钮 */
.nav-toggle{
  display:none;
  align-items:center;
  gap:.55rem;
  min-height:44px;
  padding:.5rem .8rem;
  background:rgba(10,15,44,.6);
  border:1px solid var(--hairline-strong);
  color:var(--mist);
  cursor:pointer;
  clip-path:polygon(10px 0,100% 0,100% 100%,0 100%,0 10px);
  font-family:var(--font-body);
  font-size:.8125rem;
  font-weight:600;
  letter-spacing:.12em;
  transition:border-color var(--dur) var(--ease),color var(--dur) var(--ease);
}
.nav-toggle:hover{ border-color:var(--mint); color:var(--mint); }
.nav-toggle__bars{
  display:grid;
  gap:4px;
  width:18px;
}
.nav-toggle__bars span{
  display:block;
  height:2px;
  background:currentColor;
  transition:transform var(--dur) var(--ease),opacity var(--dur) var(--ease);
}
.site-header[data-open="true"] .nav-toggle__bars span:nth-child(1){ transform:translateY(6px) rotate(45deg); }
.site-header[data-open="true"] .nav-toggle__bars span:nth-child(2){ opacity:0; }
.site-header[data-open="true"] .nav-toggle__bars span:nth-child(3){ transform:translateY(-6px) rotate(-45deg); }
.site-header[data-open="true"] .nav-toggle{ border-color:var(--gold); color:var(--gold); }

/* ============================================================
   13. 页脚
   ============================================================ */
.site-footer{
  position:relative;
  margin-top:clamp(2.5rem,7vw,5rem);
  padding-top:clamp(3.5rem,9vw,6rem);
  color:var(--mist);
  background:
    radial-gradient(90% 140% at 100% 0%,rgba(43,75,216,.42),transparent 58%),
    radial-gradient(70% 120% at 0% 8%,rgba(63,214,176,.14),transparent 55%),
    var(--ink-1);
  clip-path:polygon(0 clamp(16px,3.5vw,48px),100% 0,100% 100%,0 100%);
}

.footer-top{
  display:flex;
  flex-wrap:wrap;
  align-items:flex-end;
  justify-content:space-between;
  gap:1.25rem 2rem;
  max-width:var(--shell);
  margin-inline:auto;
  padding:0 var(--gutter) clamp(1.5rem,3vw,2.25rem);
}

.footer-brand__line{
  max-width:24ch;
  font-size:.9375rem;
  line-height:1.75;
  color:rgba(242,245,252,.76);
}

.footer-stamp{
  display:inline-flex;
  align-items:center;
  gap:.5rem;
  font-family:var(--font-mono);
  font-size:.6875rem;
  letter-spacing:.14em;
  color:var(--slate);
}
.footer-stamp__dot{
  width:7px;
  height:7px;
  background:var(--mint);
  transform:skewX(-20deg);
}

.footer-inner{
  display:grid;
  grid-template-columns:repeat(4,minmax(0,1fr));
  gap:clamp(1.5rem,3.5vw,3rem);
  max-width:var(--shell);
  margin-inline:auto;
  padding:clamp(1.75rem,4vw,2.75rem) var(--gutter) clamp(2rem,5vw,3.5rem);
  border-top:1px solid var(--hairline);
}

.footer-col{ min-width:0; }

.footer-col__title{
  display:flex;
  align-items:center;
  gap:.5rem;
  margin:0 0 1rem;
  padding-bottom:.6rem;
  border-bottom:1px solid var(--hairline);
  font-family:var(--font-mono);
  font-size:.6875rem;
  font-weight:500;
  letter-spacing:.22em;
  color:var(--slate);
}
.footer-col__title::before{
  content:"";
  width:6px;
  height:6px;
  background:var(--gold);
  transform:skewX(-20deg);
}

.footer-list{
  display:grid;
  gap:.1rem;
}

.footer-link{
  display:inline-flex;
  align-items:center;
  gap:.5rem;
  min-height:38px;
  padding:.2rem 0;
  font-size:.9375rem;
  color:rgba(242,245,252,.78);
  text-decoration:none;
  transition:color var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.footer-link::before{
  content:"";
  width:8px;
  height:1px;
  background:var(--slate);
  transition:background var(--dur) var(--ease),width var(--dur) var(--ease);
}
.footer-link:hover{ color:var(--gold); transform:translateX(2px); }
.footer-link:hover::before{ width:14px; background:var(--gold); }

.footer-link--meta{
  min-height:32px;
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.08em;
  color:var(--slate);
}
.footer-link--meta::before{ display:none; }

.footer-contact{
  display:grid;
  gap:.9rem;
}
.footer-contact__item{ display:block; }
.footer-contact__label{
  display:block;
  margin-bottom:.15rem;
  font-family:var(--font-mono);
  font-size:.625rem;
  letter-spacing:.2em;
  color:var(--slate);
}
.footer-contact__value{
  display:block;
  font-size:.9375rem;
  line-height:1.6;
  color:var(--mist);
}

.copy-mail{
  display:inline-flex;
  align-items:center;
  gap:.55rem;
  min-height:40px;
  padding:.35rem .75rem;
  border:1px solid rgba(63,214,176,.4);
  background:rgba(63,214,176,.09);
  color:var(--mint);
  font-family:var(--font-mono);
  font-size:.8125rem;
  line-height:1.3;
  word-break:break-all;
  text-align:left;
  cursor:pointer;
  clip-path:polygon(8px 0,100% 0,100% 100%,0 100%,0 8px);
  transition:background var(--dur) var(--ease),color var(--dur) var(--ease),
             border-color var(--dur) var(--ease);
}
.copy-mail:hover{ background:rgba(63,214,176,.2); border-color:var(--mint); }
.copy-mail.is-copied{
  background:var(--gold);
  border-color:var(--gold);
  color:var(--ink-0);
}
.copy-mail__hint{
  flex:0 0 auto;
  font-family:var(--font-body);
  font-size:.75rem;
  letter-spacing:.08em;
  opacity:.85;
}

.footer-bottom{
  border-top:1px solid var(--hairline);
  background:rgba(10,15,44,.6);
}
.footer-bottom__inner{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:.4rem 1.5rem;
  max-width:var(--shell);
  margin-inline:auto;
  padding:1rem var(--gutter);
}
.footer-bottom__meta{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.35rem 1.25rem;
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.08em;
  color:var(--slate);
}

/* ============================================================
   14. 响应式
   ============================================================ */
@media (max-width:1150px){
  .header-chapter{ display:none; }
}

@media (max-width:1023px){
  :root{ --header-h:64px; }

  .site-nav{
    position:fixed;
    top:var(--header-h);
    left:0;
    right:0;
    display:block;
    margin-left:0;
    padding:1rem var(--gutter) 2rem;
    max-height:calc(100dvh - var(--header-h));
    overflow-y:auto;
    background:linear-gradient(180deg,rgba(20,28,74,.99),rgba(10,15,44,.99));
    border-bottom:1px solid var(--hairline);
    box-shadow:0 30px 60px rgba(0,0,0,.55);
    clip-path:polygon(0 0,100% 0,100% calc(100% - 20px),calc(100% - 20px) 100%,0 100%);
    opacity:0;
    visibility:hidden;
    transform:translateY(-12px);
    transition:opacity var(--dur) var(--ease),transform var(--dur) var(--ease),
               visibility var(--dur) var(--ease);
  }
  .site-header[data-open="true"] .site-nav{
    opacity:1;
    visibility:visible;
    transform:translateY(0);
  }

  .nav-list{
    flex-direction:column;
    align-items:stretch;
    gap:0;
    counter-reset:navi;
  }
  .nav-list__item{
    position:relative;
    counter-increment:navi;
    border-bottom:1px solid var(--hairline);
  }
  .nav-list__item::before{
    content:"0" counter(navi);
    position:absolute;
    left:0;
    top:50%;
    transform:translateY(-50%);
    font-family:var(--font-mono);
    font-size:.6875rem;
    letter-spacing:.12em;
    color:var(--slate);
  }
  .nav-link{
    display:flex;
    justify-content:space-between;
    width:100%;
    min-height:54px;
    padding:.8rem .25rem .8rem 2.6rem;
    font-size:1.0625rem;
    letter-spacing:.08em;
  }
  .nav-link::before{ inset:6px 0; transform:skewX(-6deg) scaleX(.35); }
  .nav-link[aria-current="page"]::after{ left:2.6rem; right:.25rem; bottom:8px; }

  .nav-meta{
    display:flex;
    align-items:center;
    justify-content:space-between;
    margin-top:1.25rem;
    padding-top:1rem;
    border-top:1px dashed var(--hairline);
    font-family:var(--font-mono);
    font-size:.75rem;
    letter-spacing:.14em;
    color:var(--slate);
  }
  .nav-meta__value{ color:var(--mint); }

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

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

  .brand__tagline{ display:none; }
  .brand__name{ font-size:1rem; }
}

@media (max-width:640px){
  .header-inner{ gap:.5rem; }
  .brand__mark{ width:34px; height:34px; font-size:.9375rem; }
  .brand{ gap:.55rem; }
  .brand__name{ font-size:.9375rem; letter-spacing:.02em; }
  .version-switch__btn{ min-width:44px; min-height:36px; padding:0 .4rem; font-size:.75rem; }
  .nav-toggle{ padding:.45rem .6rem; }
  .nav-toggle__label{ display:none; }

  .footer-inner{ grid-template-columns:1fr; gap:1.75rem; }
  .footer-top{ align-items:flex-start; flex-direction:column; gap:.9rem; }
  .footer-brand__line{ max-width:none; }
  .footer-bottom__inner{ flex-direction:column; align-items:flex-start; }

  .media-frame--wide{ aspect-ratio:4 / 3; }
  .rule-item{ grid-template-columns:auto 1fr; }
}

/* ============================================================
   15. 动效降级
   ============================================================ */
@media (prefers-reduced-motion:reduce){
  html{ scroll-behavior:auto; }
  *,
  *::before,
  *::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    transition-delay:0ms !important;
  }
  .card:hover,
  .btn--gold:hover,
  .tag--active,
  .footer-link:hover,
  .toc-link:hover,
  .rule-item:hover{ transform:none; }
  .version-switch__thumb{ transition:none; }
  .progress-bar__fill{ transition:none; }
}