/* ===== reset ===== */
*,*::before,*::after{box-sizing:border-box}
html,body,h1,h2,h3,h4,p,ul,ol,li,figure,blockquote{margin:0;padding:0}
ul,ol{list-style:none}
img,svg{display:block;max-width:100%}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}

/* ===== tokens ===== */
:root{
  --orange:#E8431F;
  --orange-deep:#B32D10;
  --ink:#17181A;
  --ink-soft:#131416;
  --cream:#F7F2E9;
  --paper:#FFFDF8;
  --teal:#0E8C7F;
  --teal-light:#D7EFE9;
  --teal-deep:#0B5F57;
  --amber:#D9990F;
  --amber-light:#F7E6BC;
  --grey:#6B6E72;
  --line:#DCD3C4;
  --nav-w:236px;
  --wrap:1240px;
  --ease:cubic-bezier(.2,.7,.3,1);
  --shadow-1:0 1px 0 rgba(23,24,26,.05),0 14px 30px -22px rgba(23,24,26,.45);
}

/* ===== base ===== */
body{
  font-family:"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  font-size:16px;
  line-height:1.85;
  color:var(--ink);
  background:var(--cream);
  background-image:radial-gradient(rgba(23,24,26,.045) 1px,transparent 1px);
  background-size:22px 22px;
  -webkit-font-smoothing:antialiased;
}
#main-content{display:block;scroll-margin-top:24px}
h1,h2,h3,h4{font-weight:900;line-height:1.16;letter-spacing:-.01em}
h1{font-size:clamp(32px,5vw,56px)}
h2{font-size:clamp(26px,3.4vw,38px)}
h3{font-size:clamp(19px,2.2vw,24px)}
h4{font-size:17px}
p{max-width:46ch}
strong{font-weight:800}
:focus-visible{outline:3px solid var(--orange);outline-offset:3px}

/* ===== skip link ===== */
.skip-link{
  position:fixed;top:-120px;left:12px;z-index:120;
  padding:10px 18px;background:var(--ink);color:var(--paper);
  font-size:13px;font-weight:800;letter-spacing:.06em;
  border:3px solid var(--orange);transition:top .18s var(--ease);
}
.skip-link:focus{top:12px}

/* ===== scroll progress ===== */
.scroll-progress{
  position:fixed;top:0;left:0;height:3px;width:0;
  background:var(--orange);z-index:90;
  transition:width .1s linear;
}
@media (min-width:1024px){.scroll-progress{left:var(--nav-w)}}

/* ===== header bar ===== */
.site-header{position:relative;z-index:40;background:var(--cream)}
.header-bar{
  display:flex;align-items:center;gap:18px;flex-wrap:wrap;
  padding:12px clamp(16px,3vw,40px) 12px clamp(16px,3vw,40px);
  border-bottom:2px solid var(--ink);
}
.brand{display:flex;align-items:center;gap:12px;flex:0 0 auto}
.brand__mark{
  width:38px;height:38px;display:grid;place-items:center;
  background:var(--orange);color:#fff;font-size:20px;font-weight:900;
  --cut:11px;
  clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)));
}
.brand__text{display:flex;flex-direction:column;line-height:1.14;font-size:21px;font-weight:900;letter-spacing:.02em}
.brand__sub{font-size:11px;font-weight:700;letter-spacing:.2em;color:var(--grey);margin-top:4px}
.header-tools{display:flex;align-items:center;gap:12px;margin-left:auto;flex-wrap:wrap}

.tool-link{
  display:inline-flex;align-items:center;
  padding:7px 12px;font-size:12px;font-weight:700;letter-spacing:.08em;
  background:var(--paper);border:2px solid var(--ink);
  --cut:8px;
  clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)));
  transition:background .18s var(--ease),color .18s var(--ease),transform .18s var(--ease);
}
.tool-link:hover{background:var(--ink);color:var(--cream);transform:translateY(-2px)}

/* ===== search ===== */
.search{position:relative;display:flex;align-items:center;gap:8px}
.search__label{font-size:11px;font-weight:800;letter-spacing:.16em;color:var(--grey)}
.search__input{
  width:190px;padding:8px 12px;font-size:13px;
  background:var(--paper);border:2px solid var(--ink);color:var(--ink);
  --cut:7px;
  clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)));
}
.search__input::placeholder{color:#9B9B98}
.search__status{
  position:absolute;top:100%;left:0;margin-top:6px;z-index:10;
  padding:3px 9px;font-size:11px;font-weight:800;letter-spacing:.04em;
  color:var(--teal-deep);background:var(--paper);border:1px solid var(--line);
  white-space:nowrap;
}
.search__status:empty{display:none}

/* ===== nav toggle ===== */
.nav-toggle{
  display:none;width:44px;height:44px;align-items:center;justify-content:center;
  background:var(--orange);color:#fff;border:2px solid var(--ink);
  --cut:10px;
  clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)));
  transition:background .18s var(--ease);
}
.nav-toggle:hover{background:var(--orange-deep)}
.nav-toggle__bars{display:block;position:relative;width:18px;height:2px;background:currentColor}
.nav-toggle__bars::before,.nav-toggle__bars::after{content:"";position:absolute;left:0;width:18px;height:2px;background:currentColor}
.nav-toggle__bars::before{top:-6px}
.nav-toggle__bars::after{top:6px}

/* ===== notice band ===== */
.notice-band{
  position:relative;background:var(--teal-light);
  border-bottom:1px solid rgba(14,140,127,.45);
}
.notice-band::before{content:"";position:absolute;top:0;left:0;right:0;height:3px;background:var(--teal)}
.notice-band__inner{
  display:flex;align-items:center;gap:14px;flex-wrap:wrap;
  min-height:64px;padding:10px clamp(16px,3vw,40px);
}
.notice-band__badge{
  flex:0 0 auto;padding:5px 10px;font-size:11px;font-weight:800;letter-spacing:.14em;
  background:var(--teal);color:#fff;
  --cut:7px;
  clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)));
}
.notice-band__text{flex:1 1 260px;font-size:13.5px;line-height:1.6;color:var(--teal-deep);max-width:none}
.notice-band__toggle{
  flex:0 0 auto;font-size:12px;font-weight:800;letter-spacing:.06em;
  color:var(--teal-deep);border-bottom:2px solid var(--teal);padding:2px 0;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.notice-band__toggle:hover{color:var(--orange);border-bottom-color:var(--orange)}
.notice-band__panel{
  display:grid;grid-template-rows:0fr;
  transition:grid-template-rows .24s var(--ease);
}
.notice-band[data-expanded="true"] .notice-band__panel{grid-template-rows:1fr}
.notice-band__panel-inner{overflow:hidden;background:rgba(255,253,248,.55)}
.notice-band__list{
  display:grid;gap:6px;
  padding:4px clamp(16px,3vw,40px) 16px;
  font-size:13px;line-height:1.75;color:var(--teal-deep);
}
.notice-band__list li{display:flex;gap:8px;max-width:78ch}
.notice-band__list li::before{content:"▪";color:var(--teal);font-weight:900;flex:0 0 auto}

/* ===== left frame nav ===== */
.site-nav{
  position:fixed;inset:0 auto 0 0;width:var(--nav-w);z-index:70;
  display:flex;flex-direction:column;
  padding:20px 0 16px;
  background:var(--ink-soft);color:var(--cream);
  border-right:3px solid var(--orange);
  overflow-y:auto;
  transition:transform .28s var(--ease),visibility 0s linear .28s;
}
.site-nav__head{padding:0 20px 14px;margin-bottom:10px;border-bottom:1px solid rgba(247,242,233,.16)}
.site-nav__kicker{font-size:11px;font-weight:800;letter-spacing:.26em;color:var(--amber)}
.site-nav__title{font-size:14px;font-weight:800;color:var(--cream);margin-top:6px;line-height:1.5}
.site-nav__list{display:flex;flex-direction:column}
.site-nav__link{
  display:flex;align-items:baseline;gap:10px;
  padding:13px 18px 13px 20px;font-size:15px;font-weight:700;color:#EDE6DA;
  border-left:4px solid transparent;
  transition:background .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease),padding-left .18s var(--ease);
}
.site-nav__link:hover{background:rgba(232,67,31,.18);border-left-color:var(--orange);color:#fff;padding-left:24px}
.site-nav__link[aria-current="page"]{background:var(--orange);border-left-color:#fff;color:#fff}
.site-nav__num{
  font-family:ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  font-size:11px;font-weight:800;letter-spacing:.1em;color:var(--amber);
}
.site-nav__link[aria-current="page"] .site-nav__num{color:#FFE9C6}
.site-nav__foot{margin-top:auto;padding:18px 20px 0;border-top:1px solid rgba(247,242,233,.16)}
.site-nav__note{font-size:11px;line-height:1.8;letter-spacing:.04em;color:#9DA0A4;max-width:none}
.site-nav__spine{
  position:absolute;right:8px;bottom:20px;
  writing-mode:vertical-rl;font-size:10px;letter-spacing:.3em;
  color:rgba(247,242,233,.32);
}
.site-nav__close{
  display:none;position:absolute;top:10px;right:10px;
  width:36px;height:36px;place-items:center;
  font-size:20px;font-weight:900;color:var(--cream);
  border:2px solid rgba(247,242,233,.4);
}
.site-nav__close:hover{border-color:var(--orange);color:var(--orange)}

@media (min-width:1024px){
  body{padding-left:var(--nav-w)}
}
@media (max-width:1023px){
  .site-nav{
    width:min(84vw,320px);
    visibility:hidden;transform:translateX(-102%);
    box-shadow:24px 0 60px -30px rgba(0,0,0,.85);
  }
  .site-nav[data-open="true"]{
    visibility:visible;transform:translateX(0);
    transition:transform .28s var(--ease),visibility 0s linear 0s;
  }
  .site-nav__close{display:grid}
  .nav-toggle{display:inline-flex}
}
@media (max-width:640px){
  .brand__text{font-size:18px}
  .brand__sub{font-size:10px;letter-spacing:.14em}
  .header-bar{gap:12px;padding-block:10px}
  .header-tools{gap:8px}
  .search__label{display:none}
  .search__input{width:132px}
  .tool-link{font-size:11px;padding:6px 9px}
}

/* ===== footer ===== */
.site-footer{
  position:relative;background:var(--ink);color:#D9D2C6;
  margin-top:0;
}
.footer__rule{height:4px;background:var(--teal)}
.footer__inner{padding:clamp(30px,4vw,54px) clamp(18px,4vw,56px) 26px}
.footer__grid{
  display:grid;gap:30px;
  grid-template-columns:1.4fr 1fr 1.2fr;
  max-width:var(--wrap);margin:0 auto;
}
.footer__col{min-width:0}
.footer__title{
  font-size:12px;font-weight:800;letter-spacing:.2em;text-transform:uppercase;
  color:var(--orange);margin-bottom:14px;
}
.footer__list{display:flex;flex-direction:column;gap:7px}
.footer__link{
  display:inline-flex;align-items:center;gap:6px;
  font-size:14px;color:#D9D2C6;padding:2px 0;
  border-bottom:1px solid transparent;
  transition:color .18s var(--ease),border-color .18s var(--ease),background .18s var(--ease);
}
.footer__link:hover{color:#fff;border-bottom-color:var(--orange)}
.footer__list--chips{flex-direction:row;flex-wrap:wrap;gap:8px}
.footer__list--chips .footer__link{
  padding:6px 12px;font-size:13px;
  border:1px solid rgba(247,242,233,.24);
  background:rgba(247,242,233,.05);
  --cut:8px;
  clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)));
}
.footer__list--chips .footer__link:hover{
  background:rgba(232,67,31,.22);border-color:var(--orange);color:#fff;
}
.footer__contact{gap:12px}
.footer__item{display:flex;flex-wrap:wrap;align-items:baseline;gap:8px}
.footer__label{
  font-size:11px;font-weight:800;letter-spacing:.14em;color:var(--amber);
  flex:0 0 auto;
}
.footer__value{font-size:13.5px;color:#EDE6DA;word-break:break-word;max-width:100%}
.footer__note{margin-top:14px;font-size:12px;line-height:1.8;color:#9DA0A4;max-width:34ch}
.copy-btn{
  font-size:11px;font-weight:800;letter-spacing:.08em;
  padding:3px 9px;color:var(--teal-light);
  border:1px solid var(--teal);
  transition:background .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease);
}
.copy-btn:hover{background:var(--teal);color:#fff}
.copy-btn[data-copied="true"]{background:var(--amber);border-color:var(--amber);color:var(--ink)}
.footer__col--legal{
  grid-column:1/-1;
  display:flex;flex-wrap:wrap;align-items:center;gap:10px 26px;
  padding-top:18px;margin-top:4px;
  border-top:1px solid rgba(247,242,233,.16);
}
.footer__legal{font-size:12.5px;letter-spacing:.06em;color:#C7C0B4;max-width:none}
.footer__meta{font-size:11.5px;letter-spacing:.06em;color:#8A8D91;max-width:none}
@media (max-width:900px){
  .footer__grid{grid-template-columns:1fr 1fr}
}
@media (max-width:600px){
  .footer__grid{grid-template-columns:1fr}
  .footer__inner{padding-bottom:20px}
}

/* ===== shared page primitives ===== */
.wrap{
  width:100%;max-width:var(--wrap);
  margin:0 auto 0 clamp(0px,1.6vw,24px);
  padding-inline:clamp(16px,3vw,40px) clamp(16px,4vw,56px);
}
.grid{display:grid;gap:18px;grid-template-columns:repeat(12,1fr)}
@media (max-width:900px){.grid{grid-template-columns:repeat(6,1fr);gap:14px}}
@media (max-width:600px){.grid{grid-template-columns:1fr;gap:14px}}

.cut,.card,.card__inner,.media,.side-card,.strip,.tag,.btn{
  clip-path:polygon(0 0,calc(100% - var(--cut,14px)) 0,100% var(--cut,14px),100% 100%,var(--cut,14px) 100%,0 calc(100% - var(--cut,14px)));
}

.card{
  --cut:16px;
  position:relative;display:block;padding:2px;
  background:var(--line);box-shadow:var(--shadow-1);
  transition:transform .2s var(--ease),background .2s var(--ease);
}
.card:hover,.card:focus-within{transform:translateY(-4px);background:var(--orange)}
.card__inner{
  --cut:16px;
  display:flex;flex-direction:column;gap:10px;height:100%;
  padding:20px;background:var(--paper);
}
.card--big .card__inner{padding:26px;gap:14px}
.card--narrow .card__inner{padding:14px 16px;gap:6px}

.section-num{
  display:block;
  font-family:ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  font-size:clamp(40px,7vw,72px);font-weight:800;line-height:.82;
  letter-spacing:-.03em;color:var(--orange);
}

.strip{
  --cut:12px;
  display:flex;align-items:center;gap:14px;flex-wrap:wrap;
  min-height:64px;padding:12px 20px;
  background:var(--teal-light);border-left:6px solid var(--teal);
}
.strip--amber{background:var(--amber-light);border-left-color:var(--amber)}
.strip p{font-size:13.5px;line-height:1.65;color:var(--ink);max-width:none}

.btn{
  --cut:10px;
  display:inline-flex;align-items:center;gap:8px;
  padding:11px 20px;font-size:14px;font-weight:800;letter-spacing:.04em;
  border:2px solid transparent;
  transition:background .18s var(--ease),color .18s var(--ease),transform .18s var(--ease),border-color .18s var(--ease);
}
.btn:hover{transform:translateY(-2px)}
.btn--primary{background:var(--orange);color:#fff}
.btn--primary:hover{background:var(--orange-deep)}
.btn--ghost{background:transparent;color:var(--ink);border-color:var(--ink)}
.btn--ghost:hover{border-color:var(--orange);color:var(--orange)}

.tag{
  --cut:7px;
  display:inline-flex;align-items:center;gap:5px;
  padding:3px 9px;font-size:11.5px;font-weight:800;letter-spacing:.1em;
  border:1px solid var(--ink);color:var(--ink);background:var(--paper);
}
.tag--ink{background:var(--ink);color:var(--cream);border-color:var(--ink)}
.tag--teal{background:var(--teal-light);color:var(--teal-deep);border-color:var(--teal)}
.tag--amber{background:var(--amber-light);color:#6B4A02;border-color:var(--amber)}

.breadcrumb{
  display:flex;align-items:center;gap:8px;flex-wrap:wrap;
  font-size:12px;font-weight:700;letter-spacing:.06em;color:var(--grey);
}
.breadcrumb a{color:var(--ink);border-bottom:1px solid var(--line)}
.breadcrumb a:hover{color:var(--orange);border-bottom-color:var(--orange)}
.breadcrumb span[aria-hidden]{color:var(--line)}

.prose{max-width:46ch}
.prose p+p{margin-top:14px}
.prose p{max-width:46ch}
.prose h3{margin-top:26px;margin-bottom:10px}

.side-card{
  --cut:14px;
  padding:20px;background:var(--paper);
  border-left:6px solid var(--amber);
  box-shadow:var(--shadow-1);
}
.side-card h3{font-size:16px;margin-bottom:8px}
.side-card p{font-size:13.5px;line-height:1.8;color:var(--grey);max-width:none}
.side-card p+p{margin-top:8px}

.media{
  --cut:14px;
  position:relative;display:block;width:100%;
  aspect-ratio:16/9;overflow:hidden;
  border:2px solid var(--ink);
  background:
    repeating-linear-gradient(135deg,rgba(232,67,31,.12) 0 8px,transparent 8px 16px),
    var(--amber-light);
}
.media--wide{aspect-ratio:16/9}
.media--square{aspect-ratio:1/1}
.media--tall{aspect-ratio:3/4}
.media__img{width:100%;height:100%;object-fit:cover;display:block}

.meta{font-size:12px;line-height:1.75;color:var(--grey);letter-spacing:.03em;max-width:none}
.mono{
  font-family:ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  font-variant-numeric:tabular-nums;letter-spacing:0;
}
.annotation{
  writing-mode:vertical-rl;font-size:11px;letter-spacing:.3em;
  color:var(--grey);line-height:1;
}

.reveal{opacity:0;transform:translateY(12px);transition:opacity .3s var(--ease),transform .3s var(--ease)}
.reveal.is-in{opacity:1;transform:none}

/* ===== 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;
  }
  .reveal{opacity:1;transform:none}
  .card:hover,.card:focus-within,.btn:hover,.tool-link:hover{transform:none}
}