/* =========================================================
   MG游戏平台 · 共享样式 /assets/site.css
   深墨蓝基底 · 霓虹青信号 · 琥珀金档案 · 暖纸卡片
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,h5,p,ul,ol,figure,blockquote{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,picture{max-width:100%;display:block}
button{font:inherit;color:inherit;background:none;border:0}
a{color:inherit;text-decoration:none}
:focus-visible{outline:2px solid #3DF5E4;outline-offset:3px;border-radius:3px}
::selection{background:#3DF5E4;color:#050D18}

/* ---------- 2. 变量 ---------- */
:root{
  --ink-950:#050D18;
  --ink-850:#0A1A2E;
  --ink-700:#122B47;
  --paper:#F2E8D5;
  --cyan:#3DF5E4;
  --gold:#FFC24B;
  --coral:#FF6B5E;
  --mint:#6BE8B3;
  --fog:#F4F7FB;
  --slate:#9DB0C6;
  --line:#27415F;
  --shell:1320px;
  --r-lg:16px;
  --r-md:12px;
  --r-sm:8px;
  --gap:clamp(1rem,2.2vw,1.75rem);
  --ease:cubic-bezier(.4,0,.2,1);
  --font-serif:"Noto Serif SC","Source Han Serif SC","Songti SC",STSong,SimSun,serif;
  --font-sans:"HarmonyOS Sans SC","Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;
}

/* ---------- 3. 基础排版 ---------- */
body{
  min-height:100vh;
  background-color:var(--ink-950);
  color:var(--fog);
  font-family:var(--font-sans);
  font-size:clamp(1rem,.35vw + .94rem,1.0625rem);
  line-height:1.78;
  letter-spacing:.012em;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:0;
  pointer-events:none;
  background-image:
    linear-gradient(rgba(61,245,228,.055) 1px,transparent 1px),
    linear-gradient(90deg,rgba(61,245,228,.055) 1px,transparent 1px);
  background-size:72px 72px;
  -webkit-mask-image:radial-gradient(125% 95% at 50% 0%,#000 18%,transparent 76%);
  mask-image:radial-gradient(125% 95% at 50% 0%,#000 18%,transparent 76%);
}
h1,h2,h3,h4,h5{
  font-family:var(--font-sans);
  font-weight:800;
  line-height:1.2;
  letter-spacing:-.015em;
  color:var(--fog);
}
h1{font-size:clamp(2rem,4vw,3.3rem);font-weight:900}
h2{font-size:clamp(1.5rem,2.6vw,2.1rem)}
h3{font-size:clamp(1.15rem,1.8vw,1.4rem)}
p{max-width:68ch}
strong{color:var(--fog);font-weight:700}
section[id],div[id]{scroll-margin-top:104px}

/* ---------- 4. 工具与布局 ---------- */
.container{width:min(100% - 2rem,1180px);margin-inline:auto}
.container--wide{width:min(100% - 2rem,var(--shell));margin-inline:auto}
.container--narrow{width:min(100% - 2rem,760px);margin-inline:auto}
.section{position:relative;z-index:1;padding-block:clamp(2.5rem,6vw,5rem)}
.section-head{display:grid;gap:.55rem;max-width:66ch;margin-bottom:clamp(1.5rem,3vw,2.5rem)}
.eyebrow{
  font-family:var(--font-mono);
  font-size:.74rem;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--cyan);
}
.lede{color:var(--slate);font-size:clamp(1rem,1.2vw,1.125rem);line-height:1.8}
.chapter-num{
  display:block;
  font-family:var(--font-serif);
  font-weight:900;
  font-size:clamp(3rem,7vw,6rem);
  line-height:.84;
  letter-spacing:-.04em;
  color:rgba(61,245,228,.2);
  -webkit-text-stroke:1px rgba(61,245,228,.55);
  transition:color .35s var(--ease),-webkit-text-stroke-color .35s var(--ease);
}
[data-chapter].is-current .chapter-num{
  color:rgba(255,194,75,.18);
  -webkit-text-stroke-color:var(--gold);
}
.grid{display:grid;gap:var(--gap)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--split{grid-template-columns:minmax(0,5fr) minmax(0,7fr)}
.stack{display:grid;gap:var(--gap)}

/* ---------- 5. 按钮 ---------- */
.btn{
  --btn-bg:transparent;
  --btn-fg:var(--fog);
  --btn-bd:var(--line);
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.5rem;
  padding:.72rem 1.2rem;
  border-radius:var(--r-sm);
  border:1px solid var(--btn-bd);
  background:var(--btn-bg);
  color:var(--btn-fg);
  font-weight:700;
  font-size:.95rem;
  line-height:1.3;
  cursor:pointer;
  transition:transform .18s var(--ease),box-shadow .22s var(--ease),
             background-color .22s var(--ease),color .22s var(--ease),border-color .22s var(--ease);
}
.btn:hover{transform:translateY(-2px)}
.btn:active{transform:translateY(0)}
.btn--primary{--btn-bg:var(--gold);--btn-fg:#150E02;--btn-bd:var(--gold)}
.btn--primary:hover{box-shadow:0 14px 32px -16px rgba(255,194,75,.85)}
.btn--ghost{--btn-fg:var(--cyan);--btn-bd:rgba(61,245,228,.55);--btn-bg:rgba(61,245,228,.06)}
.btn--ghost:hover{--btn-bg:rgba(61,245,228,.16);--btn-bd:var(--cyan)}
.btn--quiet{--btn-fg:var(--slate);--btn-bd:var(--line)}
.btn--quiet:hover{--btn-fg:var(--fog);--btn-bd:var(--slate)}

/* ---------- 6. 标签 ---------- */
.tag{
  display:inline-flex;
  align-items:center;
  gap:.35rem;
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.09em;
  text-transform:uppercase;
  padding:.24rem .55rem;
  border-radius:999px;
  border:1px solid currentColor;
  line-height:1.5;
  white-space:nowrap;
}
.tag--cyan{color:var(--cyan)}
.tag--gold{color:var(--gold)}
.tag--coral{color:var(--coral)}
.tag--mint{color:var(--mint)}

/* ---------- 7. 面包屑 ---------- */
.breadcrumb{position:relative;z-index:1;padding-block:1.1rem 0}
.breadcrumb-list{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.4rem;
  font-family:var(--font-mono);
  font-size:.76rem;
  letter-spacing:.06em;
  color:var(--slate);
}
.breadcrumb-item{display:flex;align-items:center;gap:.4rem}
.breadcrumb-item:not(:first-child)::before{content:"›";color:rgba(61,245,228,.6);margin-right:.1rem}
.breadcrumb-link{color:var(--slate);transition:color .18s var(--ease)}
.breadcrumb-link:hover{color:var(--cyan)}
.breadcrumb-current{color:var(--fog)}

/* ---------- 8. 档案卡 ---------- */
.archive-card{
  position:relative;
  isolation:isolate;
  overflow:hidden;
  padding:clamp(1rem,2vw,1.5rem);
  border:1px solid var(--line);
  border-radius:var(--r-md);
  background:linear-gradient(158deg,var(--ink-700),var(--ink-850));
  transition:transform .2s var(--ease),border-color .24s var(--ease),box-shadow .24s var(--ease);
}
.archive-card::before{
  content:"";
  position:absolute;
  inset:0;
  z-index:-1;
  border-radius:inherit;
  background:linear-gradient(140deg,rgba(61,245,228,.18),transparent 58%);
  opacity:0;
  transition:opacity .28s var(--ease);
}
.archive-card:hover{transform:translateY(-3px);border-color:rgba(61,245,228,.55);box-shadow:0 22px 48px -34px rgba(61,245,228,.7)}
.archive-card:hover::before{opacity:1}
.archive-card__tag{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.12em;color:var(--gold)}
.archive-card__title{margin:.4rem 0 .55rem;font-size:1.1rem;font-weight:800;color:var(--fog)}
.archive-card__body{margin:0;color:var(--slate);font-size:.95rem;line-height:1.75}
.archive-card--paper{background:var(--paper);border-color:rgba(5,13,24,.16)}
.archive-card--paper .archive-card__title{color:var(--ink-950)}
.archive-card--paper .archive-card__body{color:#3C5570}
.archive-card--paper .archive-card__tag{color:#8A5B00}
.archive-card--paper::before{background:linear-gradient(140deg,rgba(61,245,228,.28),transparent 60%)}

/* ---------- 9. 图片容器 ---------- */
.media-frame{
  position:relative;
  overflow:hidden;
  display:grid;
  place-items:center;
  aspect-ratio:16 / 10;
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  background:
    radial-gradient(90% 90% at 15% 10%,rgba(61,245,228,.14),transparent 60%),
    radial-gradient(80% 80% at 90% 90%,rgba(255,194,75,.12),transparent 62%),
    linear-gradient(150deg,var(--ink-700),var(--ink-850));
}
.media-frame::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:repeating-linear-gradient(180deg,rgba(5,13,24,.2) 0 2px,transparent 2px 4px);
  opacity:.45;
}
.media-frame > img,
.media-frame > svg,
.media-frame > picture > img{width:100%;height:100%;object-fit:cover}
.media-frame--wide{aspect-ratio:21 / 9}
.media-frame--square{aspect-ratio:1 / 1}
.media-frame__caption{
  position:absolute;
  left:0;right:0;bottom:0;
  padding:.7rem 1rem;
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.08em;
  color:var(--slate);
  background:linear-gradient(180deg,transparent,rgba(5,13,24,.86));
}

/* ---------- 10. 跳转链接 ---------- */
.skip-link{
  position:fixed;
  top:10px;
  left:10px;
  z-index:400;
  transform:translateY(-180%);
  padding:.65rem 1.1rem;
  border-radius:var(--r-sm);
  background:var(--gold);
  color:#150E02;
  font-weight:800;
  transition:transform .18s var(--ease);
}
.skip-link:focus-visible{transform:translateY(0);outline:2px solid var(--cyan);outline-offset:3px}

/* ---------- 11. 头部 ---------- */
.site-header{
  position:sticky;
  top:0;
  z-index:80;
  background:linear-gradient(180deg,rgba(5,13,24,.97),rgba(10,26,46,.93));
  border-bottom:1px solid var(--line);
  -webkit-backdrop-filter:blur(12px);
  backdrop-filter:blur(12px);
}
.header-progress{
  position:absolute;
  left:0;right:0;bottom:-1px;
  height:2px;
  background:rgba(39,65,95,.6);
  overflow:hidden;
}
.header-progress__bar{
  display:block;
  width:0;
  height:100%;
  background:linear-gradient(90deg,var(--cyan),var(--gold));
  transition:width .12s linear;
}
.header-shell{
  width:min(100% - 2rem,var(--shell));
  margin-inline:auto;
  display:grid;
  grid-template-columns:minmax(0,5fr) minmax(0,7fr);
  align-items:center;
  gap:clamp(1rem,3vw,3rem);
  padding-block:.8rem;
}
.header-brand{
  display:flex;
  align-items:center;
  gap:.7rem;
  min-width:0;
  transition:opacity .18s var(--ease);
}
.header-brand:hover{opacity:.88}
.brand-mark{
  flex:none;
  display:grid;
  place-items:center;
  width:44px;
  height:44px;
  font-family:var(--font-mono);
  font-weight:700;
  font-size:.92rem;
  letter-spacing:.02em;
  color:var(--ink-950);
  background:linear-gradient(135deg,var(--cyan),var(--mint));
  clip-path:polygon(0 0,100% 0,100% 70%,70% 100%,0 100%);
}
.brand-text{display:grid;gap:.05rem;min-width:0}
.brand-line{font-weight:800;font-size:1.02rem;color:var(--fog);letter-spacing:.02em;line-height:1.25}
.brand-sub{font-size:.7rem;letter-spacing:.24em;color:var(--slate);line-height:1.2}
.brand-edition{
  margin-left:.35rem;
  padding:.26rem .55rem;
  border:1px solid rgba(255,194,75,.45);
  border-radius:999px;
  background:rgba(255,194,75,.09);
  color:var(--gold);
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.06em;
  white-space:nowrap;
  line-height:1.5;
}
.header-nav{
  display:flex;
  align-items:center;
  justify-content:flex-end;
  gap:clamp(.75rem,1.8vw,1.9rem);
  min-width:0;
}
.nav-list{display:flex;align-items:center;gap:clamp(.35rem,1.1vw,1.15rem);flex-wrap:wrap;justify-content:flex-end}
.nav-link{
  position:relative;
  display:inline-block;
  padding:.42rem .1rem;
  font-weight:600;
  font-size:.94rem;
  color:var(--slate);
  line-height:1.4;
  transition:color .18s var(--ease);
}
.nav-link::after{
  content:"";
  position:absolute;
  left:0;right:100%;bottom:0;
  height:2px;
  background:var(--cyan);
  transition:right .22s var(--ease),background-color .22s var(--ease);
}
.nav-link:hover,.nav-link:focus-visible{color:var(--fog)}
.nav-link:hover::after,.nav-link:focus-visible::after{right:0}
.nav-link[aria-current="page"]{color:var(--cyan);font-weight:800}
.nav-link[aria-current="page"]::after{right:0;background:var(--gold)}
.nav-quick{
  display:flex;
  align-items:center;
  gap:.4rem;
  padding-left:clamp(.6rem,1.4vw,1.1rem);
  border-left:1px solid var(--line);
}
.quick-link{
  padding:.34rem .6rem;
  border:1px solid var(--line);
  border-radius:5px;
  color:var(--slate);
  font-family:var(--font-mono);
  font-size:.74rem;
  letter-spacing:.04em;
  line-height:1.5;
  white-space:nowrap;
  transition:color .18s var(--ease),background-color .18s var(--ease),border-color .18s var(--ease);
}
.quick-link:hover,.quick-link:focus-visible{color:var(--ink-950);background:var(--fog);border-color:var(--fog)}
.quick-link--cyan{color:var(--cyan);background:rgba(61,245,228,.08);border-color:rgba(61,245,228,.42)}
.quick-link--cyan:hover,.quick-link--cyan:focus-visible{color:var(--ink-950);background:var(--cyan);border-color:var(--cyan)}
.quick-link--gold{color:var(--gold);background:rgba(255,194,75,.09);border-color:rgba(255,194,75,.45)}
.quick-link--gold:hover,.quick-link--gold:focus-visible{color:var(--ink-950);background:var(--gold);border-color:var(--gold)}
.nav-toggle{
  display:none;
  position:relative;
  z-index:120;
  align-items:center;
  gap:.5rem;
  padding:.5rem .8rem;
  border:1px solid rgba(61,245,228,.5);
  border-radius:var(--r-sm);
  color:var(--cyan);
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.1em;
  cursor:pointer;
}
.nav-toggle-bars{display:grid;gap:4px;width:16px}
.nav-toggle-bars span{
  display:block;
  height:2px;
  background:currentColor;
  transition:transform .24s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(1){transform:translateY(3px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(2){transform:translateY(-3px) rotate(-45deg)}
.nav-toggle-label{line-height:1}

/* ---------- 12. 移动快捷栏 ---------- */
.mobile-dock{
  display:none;
  position:fixed;
  left:0;right:0;bottom:0;
  z-index:90;
  justify-content:space-around;
  gap:.25rem;
  padding:.45rem .5rem calc(.45rem + env(safe-area-inset-bottom,0px));
  background:linear-gradient(180deg,rgba(10,26,46,.97),rgba(5,13,24,.99));
  border-top:1px solid var(--line);
  -webkit-backdrop-filter:blur(8px);
  backdrop-filter:blur(8px);
}
.dock-link{
  flex:1;
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:.15rem;
  padding:.35rem .4rem;
  border-radius:var(--r-sm);
  color:var(--slate);
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.04em;
  line-height:1.4;
  transition:color .18s var(--ease),background-color .18s var(--ease);
}
.dock-link:hover,.dock-link:focus-visible{color:var(--cyan);background:rgba(61,245,228,.1)}
.dock-glyph{font-size:1rem;line-height:1;color:var(--cyan)}
.dock-label{white-space:nowrap}

/* ---------- 13. 页脚 ---------- */
.site-footer{
  position:relative;
  z-index:1;
  margin-top:clamp(3rem,7vw,6rem);
  color:var(--slate);
  background:
    radial-gradient(120% 90% at 100% 0%,rgba(61,245,228,.11),transparent 55%),
    radial-gradient(100% 80% at 0% 100%,rgba(255,194,75,.09),transparent 60%),
    var(--ink-850);
  border-top:1px solid var(--line);
}
.site-footer::before{
  content:"";
  position:absolute;
  top:-1px;left:0;
  width:min(42%,420px);
  height:4px;
  background:linear-gradient(90deg,var(--cyan),var(--gold));
}
.footer-shell{
  width:min(100% - 2rem,var(--shell));
  margin-inline:auto;
  padding-block:clamp(2.25rem,5vw,3.75rem) 1.5rem;
}
.footer-top{
  display:grid;
  grid-template-columns:minmax(0,4fr) minmax(0,8fr);
  gap:clamp(1.75rem,4vw,3.5rem);
  padding-bottom:clamp(1.5rem,3vw,2.25rem);
  border-bottom:1px solid rgba(39,65,95,.85);
}
.footer-brand{display:grid;gap:.6rem;align-content:start}
.footer-mark{
  display:grid;
  place-items:center;
  width:38px;height:38px;
  font-family:var(--font-mono);
  font-weight:700;
  font-size:.82rem;
  color:var(--ink-950);
  background:linear-gradient(135deg,var(--gold),#FFE0A3);
  clip-path:polygon(0 0,100% 0,100% 70%,70% 100%,0 100%);
}
.footer-brand-line{font-weight:800;color:var(--fog);font-size:1rem;letter-spacing:.02em}
.footer-note{color:var(--slate);font-size:.9rem;line-height:1.75;max-width:34ch}
.footer-badges{display:flex;flex-wrap:wrap;gap:.45rem;margin-top:.25rem}
.footer-grid{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(1rem,2.5vw,2rem);
}
.footer-col-title{
  margin-bottom:.85rem;
  padding-bottom:.5rem;
  border-bottom:1px solid rgba(39,65,95,.9);
  font-family:var(--font-mono);
  font-size:.76rem;
  font-weight:700;
  letter-spacing:.18em;
  color:var(--fog);
}
.footer-links{display:grid;gap:.5rem}
.footer-link{
  display:inline-block;
  color:var(--slate);
  font-size:.92rem;
  line-height:1.6;
  transition:color .18s var(--ease),transform .18s var(--ease);
}
.footer-link:hover,.footer-link:focus-visible{color:var(--cyan);transform:translateX(3px)}

.footer-contact{
  display:grid;
  grid-template-columns:minmax(0,7fr) minmax(0,5fr);
  gap:clamp(1.25rem,3vw,2.75rem);
  align-items:start;
  padding-block:clamp(1.5rem,3vw,2.25rem);
  border-bottom:1px solid rgba(39,65,95,.85);
}
.contact-card{
  position:relative;
  overflow:hidden;
  padding:clamp(1rem,2.2vw,1.6rem);
  border-radius:var(--r-md);
  background:var(--paper);
  color:var(--ink-950);
  box-shadow:0 30px 60px -46px rgba(0,0,0,.95);
}
.contact-card::after{
  content:"";
  position:absolute;
  top:-56px;right:-56px;
  width:150px;height:150px;
  background:linear-gradient(135deg,rgba(61,245,228,.45),transparent 70%);
  transform:rotate(14deg);
  pointer-events:none;
}
.contact-card-title{
  margin-bottom:.6rem;
  font-family:var(--font-mono);
  font-size:.76rem;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:#3C5570;
}
.contact-row{
  display:flex;
  align-items:center;
  flex-wrap:wrap;
  gap:.55rem;
  padding:.5rem 0;
  border-bottom:1px dashed rgba(5,13,24,.2);
}
.contact-row:last-of-type{border-bottom:0}
.contact-label{
  flex:none;
  min-width:3rem;
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.1em;
  color:#5A7391;
}
.contact-value{
  flex:1 1 auto;
  min-width:0;
  font-family:var(--font-mono);
  font-size:.9rem;
  font-weight:600;
  color:var(--ink-950);
  word-break:break-word;
}
.copy-btn{
  flex:none;
  padding:.24rem .55rem;
  border:1px solid rgba(5,13,24,.3);
  border-radius:5px;
  color:var(--ink-950);
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.05em;
  line-height:1.6;
  cursor:pointer;
  transition:background-color .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease);
}
.copy-btn:hover,.copy-btn:focus-visible{background:var(--ink-950);color:var(--paper);border-color:var(--ink-950)}
.copy-btn[data-copied]{background:var(--mint);border-color:var(--mint);color:#04241A}
.contact-note{margin-top:.7rem;font-size:.82rem;line-height:1.7;color:#4A6076;max-width:none}

.footer-actions{display:grid;gap:.55rem;justify-items:start;align-content:start}
.footer-actions-title{font-weight:800;color:var(--fog);font-size:1.05rem}
.footer-actions-note{color:var(--slate);font-size:.9rem;line-height:1.7;margin-bottom:.35rem}
.footer-actions .btn{width:100%}

.footer-bottom{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:.85rem 1.5rem;
  padding-top:1.4rem;
  font-size:.82rem;
}
.footer-legal{color:var(--slate)}
.footer-icp{
  font-family:var(--font-mono);
  font-size:.76rem;
  letter-spacing:.06em;
  color:#7B90A8;
}
.footer-legal-nav{display:flex;flex-wrap:wrap;gap:1rem}
.footer-legal-nav .footer-link{font-size:.82rem}

.to-top{
  position:fixed;
  right:clamp(.8rem,2vw,1.6rem);
  bottom:clamp(.8rem,2vw,1.6rem);
  z-index:85;
  display:grid;
  place-items:center;
  width:44px;height:44px;
  border:1px solid var(--line);
  border-radius:var(--r-md);
  background:rgba(10,26,46,.94);
  color:var(--cyan);
  font-size:1.05rem;
  line-height:1;
  cursor:pointer;
  opacity:0;
  visibility:hidden;
  transform:translateY(10px);
  transition:opacity .22s var(--ease),transform .22s var(--ease),visibility .22s var(--ease),
             border-color .22s var(--ease);
}
.to-top[data-visible]{opacity:1;visibility:visible;transform:translateY(0)}
.to-top:hover,.to-top:focus-visible{border-color:var(--cyan);box-shadow:0 0 0 3px rgba(61,245,228,.14)}

/* ---------- 14. 平板与移动断点 ---------- */
@media (max-width:1040px){
  body{padding-bottom:calc(70px + env(safe-area-inset-bottom,0px))}
  .header-shell{grid-template-columns:minmax(0,1fr) auto;gap:1rem}
  .header-nav{
    position:fixed;
    inset:0 0 0 auto;
    width:min(88vw,360px);
    display:flex;
    flex-direction:column;
    align-items:stretch;
    justify-content:flex-start;
    gap:1.25rem;
    padding:calc(5.5rem + env(safe-area-inset-top,0px)) 1.5rem 2rem;
    background:linear-gradient(160deg,var(--ink-850),var(--ink-950) 78%);
    border-left:1px solid var(--line);
    box-shadow:-30px 0 70px rgba(5,13,24,.75);
    transform:translateX(102%);
    visibility:hidden;
    overflow-y:auto;
    z-index:110;
    transition:transform .3s var(--ease),visibility .3s var(--ease);
  }
  .header-nav[data-open]{transform:translateX(0);visibility:visible}
  .nav-list{flex-direction:column;align-items:stretch;gap:0;justify-content:flex-start}
  .nav-item{border-bottom:1px solid rgba(39,65,95,.7)}
  .nav-link{display:block;padding:.9rem .2rem;font-size:1.05rem}
  .nav-link::after{display:none}
  .nav-link[aria-current="page"]{padding-left:.9rem}
  .nav-link[aria-current="page"]::before{
    content:"";
    position:absolute;
    left:0;top:50%;
    width:4px;height:18px;
    margin-top:-9px;
    background:var(--gold);
    border-radius:2px;
  }
  .nav-quick{
    flex-direction:column;
    align-items:stretch;
    gap:.5rem;
    padding-left:0;
    padding-top:1.1rem;
    border-left:0;
    border-top:1px solid var(--line);
  }
  .quick-link{padding:.62rem .8rem;text-align:center;font-size:.82rem}
  .nav-toggle{display:inline-flex}
  .brand-edition{display:none}
  .mobile-dock{display:flex}
  .footer-top{grid-template-columns:minmax(0,1fr);gap:1.75rem}
  .footer-contact{grid-template-columns:minmax(0,1fr)}
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid--split{grid-template-columns:minmax(0,1fr)}
}

@media (max-width:760px){
  .brand-line{font-size:.96rem}
  .brand-sub{font-size:.64rem;letter-spacing:.18em}
  .brand-mark{width:38px;height:38px;font-size:.8rem}
  .nav-toggle-label{display:none}
  .grid--2,.grid--3{grid-template-columns:minmax(0,1fr)}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:1.25rem}
  .footer-bottom{flex-direction:column;align-items:flex-start}
  .footer-actions .btn{width:auto}
  .to-top{right:.8rem;bottom:calc(78px + env(safe-area-inset-bottom,0px))}
  .contact-value{font-size:.84rem}
  .chapter-num{font-size:clamp(2.6rem,14vw,4rem)}
}

@media (max-width:420px){
  .footer-grid{grid-template-columns:minmax(0,1fr)}
}

/* ---------- 15. 动效与无障碍 ---------- */
@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;
  }
  .btn:hover,.archive-card:hover,.footer-link:hover{transform:none}
  .to-top{transition:none}
}