*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,p,ul,ol,figure,blockquote{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,video{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0}
[hidden]{display:none!important}

:root{
  --ink-900:#0A2A25;
  --ink-700:#123C34;
  --ink-800:#0C332D;
  --orange:#FF7A2F;
  --amber:#FFC46B;
  --cyan:#4CE0D2;
  --red:#E0455C;
  --wine:#6B1F33;
  --indigo:#262052;
  --bone:#F3EFE4;
  --lead:#1A1F1E;
  --gray:#5C6663;
  --white:#FFFFFF;
  --line-dark:rgba(243,239,228,.16);
  --line-dark-soft:rgba(243,239,228,.09);
  --line-light:rgba(26,31,30,.14);
  --rail-w:92px;
  --header-h:76px;
  --content:1184px;
  --cut:14px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --font-head:"Archivo Black","Oswald","Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Inter","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,"Noto Sans Mono",monospace;
}

body{
  padding-left:var(--rail-w);
  background:var(--bone);
  color:var(--lead);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

h1,h2,h3,h4{
  font-family:var(--font-head);
  font-weight:900;
  letter-spacing:-.02em;
  line-height:1.06;
  text-wrap:balance;
}
p{margin:0 0 1.1em}
p:last-child{margin-bottom:0}
strong{font-weight:500}

:where(a,button,summary,[tabindex]):focus-visible{
  outline:3px solid var(--orange);
  outline-offset:3px;
  border-radius:2px;
}
.site-header :focus-visible,
.site-footer :focus-visible,
.site-rail :focus-visible,
.section--dark :focus-visible,
.section--wine :focus-visible,
.section--indigo :focus-visible{outline-color:var(--cyan)}
.btn:focus-visible,.to-top:focus-visible,.copy-btn:focus-visible,.chip:focus-visible{
  box-shadow:inset 0 0 0 2px currentColor;
}

/* ===== utilities ===== */
.mono{font-family:var(--font-mono);letter-spacing:.06em;font-variant-ligatures:none}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.wrap{width:100%;max-width:var(--content);margin-inline:auto;padding-inline:clamp(16px,3vw,32px)}
.section{padding-block:clamp(48px,7vw,96px);position:relative}
.section--dark{background:var(--ink-900);color:var(--bone)}
.section--bone{background:var(--bone);color:var(--lead)}
.section--wine{background:var(--wine);color:var(--bone)}
.section--indigo{background:var(--indigo);color:var(--bone)}
.grain{position:relative}
.grain::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:radial-gradient(rgba(243,239,228,.055) 1px,transparent 1px);
  background-size:3px 3px;
}
.rule{height:1px;border:0;background:var(--line-light);margin:0}
.section--dark .rule,.section--wine .rule,.section--indigo .rule{background:var(--line-dark)}
.stack > * + *{margin-top:var(--stack-gap,24px)}
.split{display:grid;gap:clamp(24px,4vw,48px);grid-template-columns:minmax(0,1fr)}
.display-1{font-size:clamp(44px,7vw,108px);line-height:.95;letter-spacing:-.03em}
.display-2{font-size:clamp(34px,5.2vw,68px);line-height:.98}
.h2{font-size:clamp(28px,3.4vw,48px);line-height:1.05}
.h3{font-size:clamp(22px,2.2vw,26px);line-height:1.22}
.eyebrow{font-family:var(--font-mono);font-size:12px;letter-spacing:.24em;text-transform:uppercase;color:var(--orange)}
.section--dark .eyebrow,.section--wine .eyebrow,.section--indigo .eyebrow{color:var(--cyan)}
.lead{font-size:clamp(18px,1.5vw,20px);line-height:1.65;max-width:62ch;color:inherit}
.prose{max-width:68ch}
.prose p + p{margin-top:24px}
.prose a{color:var(--orange);text-decoration:underline;text-underline-offset:3px}
.tag{display:inline-block;font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;padding:5px 9px;border:1px solid currentColor;opacity:.9}

/* ===== skip link ===== */
.skip-link{
  position:fixed;top:10px;left:calc(var(--rail-w) + 14px);z-index:300;
  transform:translateY(-180%);
  background:var(--orange);color:#1a0e05;
  font-family:var(--font-mono);font-size:13px;letter-spacing:.08em;
  padding:12px 18px;
  clip-path:polygon(12px 0,100% 0,100% 100%,0 100%,0 12px);
  transition:transform .22s var(--ease);
}
.skip-link:focus{transform:none}

/* ===== header ===== */
.site-header{
  position:sticky;top:0;z-index:50;
  background:var(--ink-900);
  color:var(--bone);
  border-bottom:1px solid var(--line-dark);
}
.site-header::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:radial-gradient(rgba(243,239,228,.06) 1px,transparent 1px);
  background-size:4px 4px;opacity:.45;
}
.header-inner{
  position:relative;
  display:flex;align-items:center;gap:20px;
  min-height:var(--header-h);
  max-width:var(--content);margin-inline:auto;
  padding:10px clamp(16px,3vw,32px);
}
.brand{display:flex;align-items:center;gap:14px;min-width:0}
.brand-mark{
  flex:0 0 auto;width:38px;height:38px;
  display:flex;flex-direction:column;justify-content:center;gap:3px;
  padding:0 8px;background:var(--orange);
  clip-path:polygon(10px 0,100% 0,100% calc(100% - 10px),calc(100% - 10px) 100%,0 100%,0 10px);
  transition:transform .25s var(--ease);
}
.brand-mark i{display:block;height:3px;background:var(--ink-900);border-radius:1px}
.brand-mark i:nth-child(1){width:58%}
.brand-mark i:nth-child(2){width:80%}
.brand-mark i:nth-child(3){width:100%}
.brand:hover .brand-mark{transform:translateY(-2px)}
.brand-text{display:flex;flex-direction:column;gap:2px;min-width:0}
.brand-line{font-family:var(--font-head);font-weight:900;font-size:19px;letter-spacing:.01em;white-space:nowrap;color:var(--bone)}
.brand-tagline{font-size:12px;letter-spacing:.06em;color:rgba(243,239,228,.6);white-space:nowrap}
.header-tools{margin-left:auto;display:flex;align-items:center;gap:12px}
.version-badge{
  font-family:var(--font-mono);font-size:12px;letter-spacing:.12em;
  color:var(--cyan);border:1px solid rgba(76,224,210,.42);
  background:rgba(76,224,210,.08);
  padding:6px 10px;
  clip-path:polygon(8px 0,100% 0,100% 100%,0 100%,0 8px);
}
.scroll-progress{
  position:absolute;left:0;right:0;bottom:-1px;height:2px;
  background:rgba(243,239,228,.08);pointer-events:none;
}
.scroll-progress span{
  display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--orange),var(--amber) 55%,var(--cyan));
  transition:width .12s linear;
}

/* ===== buttons ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 20px;
  font-size:14px;font-weight:500;letter-spacing:.02em;line-height:1.2;
  text-decoration:none;border:1px solid transparent;cursor:pointer;
  clip-path:polygon(var(--cut) 0,100% 0,100% calc(100% - var(--cut)),calc(100% - var(--cut)) 100%,0 100%,0 var(--cut));
  transition:background-color .22s var(--ease),color .22s var(--ease),border-color .22s var(--ease),transform .22s var(--ease);
}
.btn:hover{transform:translateY(-2px)}
.btn--primary{background:var(--orange);color:#1a0e05}
.btn--primary:hover{background:var(--amber)}
.btn--ghost{border-color:rgba(243,239,228,.32);color:var(--bone)}
.btn--ghost:hover{border-color:var(--orange);color:var(--amber)}
.btn--sm{padding:8px 14px;font-size:13px}

/* ===== rail navigation ===== */
.site-rail{
  position:fixed;top:0;left:0;bottom:0;z-index:60;
  width:var(--rail-w);
  display:flex;flex-direction:column;
  padding:18px 0 16px;
  background:var(--ink-700);
  border-right:1px solid var(--line-dark);
}
.site-rail::after{
  content:"";position:absolute;top:0;bottom:0;right:0;width:5px;pointer-events:none;
  background:repeating-linear-gradient(180deg,rgba(255,196,107,.22) 0 2px,transparent 2px 9px);
  opacity:.55;
}
.rail-list{margin:auto 0;display:flex;flex-direction:column;gap:0;padding:0}
.rail-link{
  position:relative;display:flex;flex-direction:column;align-items:center;justify-content:center;
  gap:7px;padding:11px 4px;
  color:rgba(243,239,228,.66);
  transition:color .2s var(--ease),background-color .2s var(--ease);
}
.rail-link::before{
  content:"";position:absolute;left:0;top:6px;bottom:6px;width:3px;
  background:var(--orange);
  transform:scaleY(0);transform-origin:center;
  transition:transform .25s var(--ease);
}
.rail-num{font-family:var(--font-mono);font-size:10px;letter-spacing:.14em;color:rgba(76,224,210,.72);line-height:1}
.rail-label{writing-mode:vertical-rl;font-size:13px;letter-spacing:.22em;line-height:1;color:inherit}
.rail-link:hover{color:var(--bone);background:rgba(10,42,37,.6)}
.rail-link:hover::before{transform:scaleY(.62)}
.rail-link[aria-current="page"]{color:var(--amber);background:rgba(10,42,37,.72)}
.rail-link[aria-current="page"] .rail-num{color:var(--amber)}
.rail-link[aria-current="page"]::before{transform:scaleY(1)}
.rail-foot{
  margin-top:auto;display:flex;flex-direction:column;align-items:center;gap:10px;
  padding-top:12px;border-top:1px solid var(--line-dark-soft);
}
.rail-dot{width:6px;height:6px;border-radius:50%;background:var(--cyan);box-shadow:0 0 10px rgba(76,224,210,.85)}
.rail-version{writing-mode:vertical-rl;font-size:10px;letter-spacing:.18em;color:rgba(243,239,228,.45)}
.rail-cta{display:none}

@media (hover:hover) and (pointer:fine){
  .rail-link::after{
    content:attr(data-label);
    position:absolute;left:calc(100% + 10px);top:50%;
    transform:translate(-6px,-50%);
    white-space:nowrap;
    background:var(--orange);color:#1a0e05;
    font-family:var(--font-body);font-size:12px;font-weight:500;letter-spacing:.04em;
    padding:6px 11px;
    opacity:0;pointer-events:none;z-index:3;
    clip-path:polygon(6px 0,100% 0,100% 100%,0 100%,0 6px);
    transition:opacity .18s var(--ease),transform .18s var(--ease);
  }
  .rail-link:hover::after,.rail-link:focus-visible::after{opacity:1;transform:translate(0,-50%)}
}

/* ===== nav toggle ===== */
.nav-toggle{
  display:none;align-items:center;gap:9px;
  padding:9px 13px;
  border:1px solid rgba(243,239,228,.28);
  color:var(--bone);cursor:pointer;
  clip-path:polygon(10px 0,100% 0,100% calc(100% - 10px),calc(100% - 10px) 100%,0 100%,0 10px);
  transition:border-color .2s var(--ease),color .2s var(--ease);
}
.nav-toggle:hover{border-color:var(--orange);color:var(--amber)}
.nav-toggle-bars{display:flex;flex-direction:column;gap:3px;width:16px}
.nav-toggle-bars i{display:block;height:2px;width:100%;background:currentColor;transition:transform .22s var(--ease),opacity .22s var(--ease)}
.nav-toggle-text{font-family:var(--font-mono);font-size:11px;letter-spacing:.14em}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars i:nth-child(1){transform:translateY(5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars i:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars i:nth-child(3){transform:translateY(-5px) rotate(-45deg)}

/* ===== footer ===== */
.site-footer{
  position:relative;
  background:var(--ink-900);color:var(--bone);
  border-top:1px solid var(--line-dark);
  padding-block:clamp(40px,6vw,72px) 0;
}
.site-footer::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:radial-gradient(rgba(243,239,228,.055) 1px,transparent 1px);
  background-size:3px 3px;opacity:.55;
}
.footer-inner{position:relative;width:100%;max-width:var(--content);margin-inline:auto;padding-inline:clamp(16px,3vw,32px)}
.footer-top{
  display:grid;gap:clamp(28px,4vw,44px);
  grid-template-columns:minmax(0,1.7fr) minmax(0,1fr) minmax(0,1fr) minmax(0,1fr);
}
.brand--footer{margin-bottom:16px}
.footer-intro{max-width:34ch;font-size:15px;line-height:1.7;color:rgba(243,239,228,.72)}
.footer-stamp{
  margin-top:16px;font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  color:rgba(76,224,210,.8);
}
.footer-col-title{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.22em;
  color:rgba(243,239,228,.5);font-weight:400;margin-bottom:14px;
}
.footer-links{display:grid;gap:2px}
.footer-link{
  position:relative;display:inline-block;padding:5px 0 5px 14px;
  font-size:15px;color:rgba(243,239,228,.82);
  transition:color .2s var(--ease),padding-left .2s var(--ease);
}
.footer-link::before{
  content:"";position:absolute;left:0;top:50%;width:5px;height:1px;
  background:var(--orange);transform:translateY(-50%) scaleX(.6);transform-origin:left;
  transition:transform .2s var(--ease);
}
.footer-link:hover{color:var(--amber);padding-left:18px}
.footer-link:hover::before{transform:translateY(-50%) scaleX(1)}

.footer-contact{
  display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1px;
  margin-top:clamp(32px,4vw,56px);
  background:var(--line-dark);border:1px solid var(--line-dark);
}
.contact-cell{display:flex;flex-direction:column;gap:6px;padding:18px 20px;background:var(--ink-700)}
.contact-label{font-family:var(--font-mono);font-size:10px;letter-spacing:.2em;color:var(--cyan)}
.contact-value{font-size:15px;line-height:1.55;color:rgba(243,239,228,.9);word-break:break-word}
.footer-note{margin-top:16px;font-size:13px;line-height:1.7;color:rgba(243,239,228,.6)}
.footer-note a{color:var(--amber);text-decoration:underline;text-underline-offset:3px}

.footer-legal{
  display:flex;flex-wrap:wrap;align-items:center;gap:14px 24px;
  margin-top:clamp(28px,3vw,40px);padding-block:20px 28px;
  border-top:1px solid var(--line-dark);
  font-size:13px;color:rgba(243,239,228,.6);
}
.legal-copy{margin:0}
.legal-icp{margin:0;font-size:12px;letter-spacing:.1em;color:rgba(243,239,228,.52)}
.footer-shortcuts{margin-left:auto;display:flex;flex-wrap:wrap;align-items:center;gap:10px 18px}
.copy-btn{
  font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;
  padding:7px 12px;border:1px solid rgba(255,122,47,.5);color:var(--amber);
  cursor:pointer;
  clip-path:polygon(8px 0,100% 0,100% 100%,0 100%,0 8px);
  transition:background-color .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease);
}
.copy-btn:hover{background:var(--orange);color:#1a0e05;border-color:var(--orange)}
.copy-btn.is-copied{border-color:var(--cyan);color:var(--cyan)}
.legal-link{color:rgba(243,239,228,.7);font-size:13px;padding-block:4px;border-bottom:1px solid transparent;transition:color .2s var(--ease),border-color .2s var(--ease)}
.legal-link:hover{color:var(--amber);border-color:currentColor}

/* ===== breadcrumb ===== */
.breadcrumb{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;
  color:var(--gray);padding:0;margin:0;list-style:none;
}
.breadcrumb li{display:flex;align-items:center;gap:8px}
.breadcrumb li + li::before{content:"/";color:rgba(26,31,30,.3)}
.breadcrumb a{color:inherit;transition:color .2s var(--ease)}
.breadcrumb a:hover{color:var(--orange)}
.breadcrumb [aria-current="page"]{color:var(--lead)}
.breadcrumb--dark{color:rgba(243,239,228,.62)}
.breadcrumb--dark li + li::before{color:rgba(243,239,228,.3)}
.breadcrumb--dark [aria-current="page"]{color:var(--bone)}
.breadcrumb--dark a:hover{color:var(--amber)}

/* ===== cards ===== */
.card{
  position:relative;
  padding:clamp(20px,2.4vw,28px);
  background:var(--white);
  border:1px solid var(--line-light);
  clip-path:polygon(var(--cut) 0,100% 0,100% calc(100% - var(--cut)),calc(100% - var(--cut)) 100%,0 100%,0 var(--cut));
  transition:transform .25s var(--ease),box-shadow .25s var(--ease);
}
.card:hover{transform:translateY(-6px);box-shadow:0 20px 40px -28px rgba(10,42,37,.55)}
.card--dark{background:var(--ink-700);border-color:var(--line-dark);color:var(--bone)}

/* ===== media frames ===== */
.media-frame{
  position:relative;overflow:hidden;isolation:isolate;
  background:linear-gradient(150deg,var(--ink-700),var(--ink-900) 62%,#071d19);
  border:1px solid var(--line-dark);
  clip-path:polygon(16px 0,100% 0,100% calc(100% - 16px),calc(100% - 16px) 100%,0 100%,0 16px);
}
.media-frame img,.media-frame svg,.media-frame picture{width:100%;height:100%;object-fit:cover;display:block}
.media-frame::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:
    radial-gradient(120% 90% at 18% 0%,rgba(255,122,47,.2),transparent 58%),
    radial-gradient(110% 110% at 100% 100%,rgba(10,42,37,.6),transparent 62%);
}
.media-frame--16x9{aspect-ratio:16/9}
.media-frame--4x3{aspect-ratio:4/3}
.media-frame--3x4{aspect-ratio:3/4}
.media-frame--wide{aspect-ratio:21/9}
.media-frame figcaption{
  position:absolute;left:0;bottom:0;z-index:2;
  padding:10px 14px;font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;
  background:rgba(10,42,37,.82);color:rgba(243,239,228,.86);
}

/* ===== chips ===== */
.chips{display:flex;flex-wrap:wrap;gap:8px;padding:0;margin:0;list-style:none}
.chip{
  font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;
  padding:8px 14px;cursor:pointer;
  border:1px solid var(--line-light);color:var(--gray);background:transparent;
  clip-path:polygon(8px 0,100% 0,100% 100%,0 100%,0 8px);
  transition:background-color .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease);
}
.chip:hover{border-color:var(--orange);color:var(--lead)}
.chip[aria-pressed="true"]{background:var(--ink-700);border-color:transparent;color:var(--amber)}
.section--dark .chip,.section--wine .chip,.section--indigo .chip{border-color:var(--line-dark);color:rgba(243,239,228,.7)}
.section--dark .chip:hover,.section--wine .chip:hover,.section--indigo .chip:hover{color:var(--bone);border-color:var(--orange)}

/* ===== toc ===== */
.toc{position:sticky;top:calc(var(--header-h) + 24px);padding-left:16px;border-left:1px solid var(--line-light)}
.toc-title{font-family:var(--font-mono);font-size:11px;letter-spacing:.2em;color:var(--gray);margin-bottom:12px}
.toc-list{display:grid;gap:4px}
.toc-link{
  display:block;padding:6px 0 6px 12px;margin-left:-18px;
  font-size:14px;line-height:1.5;color:var(--gray);
  border-left:2px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.toc-link:hover{color:var(--lead)}
.toc-link.is-active{color:var(--lead);border-color:var(--orange);font-weight:500}
.toc--dark{border-left-color:var(--line-dark)}
.toc--dark .toc-title{color:rgba(243,239,228,.55)}
.toc--dark .toc-link{color:rgba(243,239,228,.65)}
.toc--dark .toc-link:hover{color:var(--bone)}
.toc--dark .toc-link.is-active{color:var(--amber);border-color:var(--amber)}

/* ===== data bits ===== */
.scoreboard{display:flex;align-items:flex-end;gap:8px;color:var(--cyan)}
.scoreboard-num{font-family:var(--font-mono);font-size:clamp(40px,6vw,76px);line-height:.9;letter-spacing:-.02em;font-weight:700}
.scoreboard-unit{font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;color:rgba(243,239,228,.6);padding-bottom:.55em}
.section--bone .scoreboard-unit{color:var(--gray)}
.meter{position:relative;height:8px;overflow:hidden;background:rgba(243,239,228,.16)}
.section--bone .meter{background:rgba(26,31,30,.12)}
.meter-fill{display:block;height:100%;background:linear-gradient(90deg,var(--orange),var(--amber))}

/* ===== to top ===== */
.to-top{
  position:fixed;right:20px;bottom:20px;z-index:70;
  display:inline-flex;align-items:center;gap:10px;
  padding:12px 16px;
  background:var(--ink-700);color:var(--bone);
  border:1px solid rgba(255,122,47,.55);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;
  cursor:pointer;
  clip-path:polygon(12px 0,100% 0,100% 100%,0 100%,0 12px);
  opacity:0;transform:translateY(14px);pointer-events:none;
  transition:opacity .25s var(--ease),transform .25s var(--ease),background-color .2s var(--ease),color .2s var(--ease);
}
.to-top.is-visible{opacity:1;transform:none;pointer-events:auto}
.to-top:hover{background:var(--orange);color:#1a0e05;border-color:var(--orange)}
.to-top-num{font-size:14px;color:var(--amber);line-height:1}
.to-top:hover .to-top-num{color:#1a0e05}
.to-top-label{max-width:12em;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

/* ===== reveal ===== */
.has-js [data-reveal]{opacity:0;transform:translateY(18px);transition:opacity .5s var(--ease),transform .5s var(--ease)}
.has-js [data-reveal].is-in{opacity:1;transform:none}

/* ===== anchors ===== */
#main-content{scroll-margin-top:calc(var(--header-h) + 16px)}
#main-content:focus{outline:none}
[data-section]{scroll-margin-top:calc(var(--header-h) + 24px)}
main{display:block}

/* ===== responsive ===== */
@media (min-width:900px){
  .split{grid-template-columns:minmax(0,7fr) minmax(0,5fr)}
  .split--even{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
  .split--5-7{grid-template-columns:minmax(0,5fr) minmax(0,7fr)}
}
@media (max-width:1183px){
  .brand-tagline{display:none}
  .footer-top{grid-template-columns:minmax(0,1.5fr) minmax(0,1fr) minmax(0,1fr)}
  .footer-top > .footer-col:last-child{grid-column:span 3}
}
@media (max-width:899px){
  :root{--rail-w:0px;--header-h:68px}
  body{padding-left:0}
  html.nav-open{overflow:hidden}
  .nav-toggle{display:inline-flex}
  .header-tools .btn{display:none}
  .site-rail{
    top:auto;left:0;right:0;bottom:0;width:auto;
    max-height:86vh;overflow-y:auto;
    padding:18px 16px calc(18px + env(safe-area-inset-bottom));
    border-right:0;border-top:2px solid var(--orange);
    background:var(--ink-800);
    z-index:75;
    transform:translateY(103%);
    visibility:hidden;
    box-shadow:0 -26px 60px -22px rgba(0,0,0,.7);
    transition:transform .34s var(--ease),visibility .34s var(--ease);
  }
  .site-rail[data-open]{transform:none;visibility:visible}
  .site-rail::after{display:none}
  .rail-list{margin:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}
  .rail-link{
    flex-direction:row-reverse;justify-content:space-between;align-items:center;
    padding:14px 14px;gap:10px;
    background:rgba(10,42,37,.42);
    border:1px solid var(--line-dark-soft);
  }
  .rail-link::before{top:0;bottom:0;width:3px}
  .rail-label{writing-mode:horizontal-tb;font-size:15px;letter-spacing:.08em}
  .rail-num{font-size:10px}
  .rail-link:hover{background:rgba(10,42,37,.7)}
  .rail-foot{
    margin-top:18px;padding-top:16px;
    flex-direction:row;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px;
  }
  .rail-version{writing-mode:horizontal-tb}
  .rail-cta{display:flex;flex-wrap:wrap;gap:8px;width:100%}
  .rail-cta .btn{flex:1 1 auto}
  .footer-top{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-top > .footer-col:last-child{grid-column:auto}
  .footer-brand{grid-column:1 / -1}
  .footer-contact{grid-template-columns:minmax(0,1fr)}
  .footer-shortcuts{margin-left:0;width:100%}
  .to-top{right:14px;bottom:14px;padding:10px 13px;font-size:11px}
  .toc{position:static;top:auto}
}
@media (max-width:640px){
  body{font-size:16px}
  .header-inner{gap:12px;padding-inline:14px}
  .brand-line{font-size:16px;white-space:normal;line-height:1.2}
  .brand-mark{width:34px;height:34px;padding:0 7px}
  .version-badge{font-size:10px;padding:5px 8px;letter-spacing:.08em}
  .nav-toggle{padding:8px 10px}
  .nav-toggle-text{display:none}
  .footer-top{grid-template-columns:minmax(0,1fr)}
  .footer-top > .footer-col:last-child{grid-column:auto}
  .legal-icp{width:100%}
  .to-top-label{max-width:7em}
}
@media (max-height:700px) and (min-width:900px){
  .rail-link{padding-block:7px}
  .rail-label{font-size:12px;letter-spacing:.16em}
}

/* ===== reduced motion ===== */
@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;
  }
  .has-js [data-reveal]{opacity:1;transform:none;transition:none}
  .btn:hover,.card:hover,.to-top{transform:none}
}