/* Reset, type, nav, footer, buttons. */
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:auto;background:var(--page)}
body{
  font-family:'Inter',sans-serif;font-size:15px;line-height:1.6;
  color:var(--white);background:var(--black);-webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
.gridbg{
  position:fixed;inset:0;pointer-events:none;z-index:0;opacity:.7;
  background-image:
    linear-gradient(to right,rgba(var(--ink),0.058) 1px,transparent 1px),
    linear-gradient(to bottom,rgba(var(--ink),0.058) 1px,transparent 1px);
  background-size:96px 96px;
  -webkit-mask-image:radial-gradient(1200px 800px at 20% 10%,#000 20%,transparent 80%);
  mask-image:radial-gradient(1200px 800px at 20% 10%,#000 20%,transparent 80%);
}
nav,header,section,footer,.unfold,.problem,.example{position:relative;z-index:1}
a{color:inherit;text-decoration:none}
.mono{font-family:"Geist Mono",ui-monospace,monospace}
.wrap{max-width:1240px;margin:0 auto;padding:0 40px}
.eyebrow{font-family:"Geist Mono",ui-monospace,monospace;font-size:12px;color:var(--accent-text);margin-bottom:18px;display:block}
h1,h2,h3{font-weight:400;letter-spacing:normal;line-height:1.1}
h2{font-size:40px;margin-bottom:18px}
h3{font-size:20px;letter-spacing:-.01em;margin-bottom:8px}
p{color:var(--mute);max-width:var(--col)}
p strong{color:var(--white);font-weight:500}
.btn{
  display:inline-flex;align-items:center;gap:8px;background:var(--lime);color:#111;
  font-weight:500;font-size:14px;padding:11px 20px;border-radius:999px;
  transition:transform .2s var(--ease-out);
}
.btn:hover{transform:translateY(-1px)}
.btn:focus-visible,a:focus-visible,button:focus-visible{outline:2px solid var(--lime);outline-offset:3px}
.btn-ghost{background:transparent;color:#111;border:1px solid rgba(var(--ink),0.160)}
.cta-row{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
#nav.condensed{height:68px;background:rgba(255,255,255,0.160);backdrop-filter:blur(14px);border-bottom:1px solid rgba(var(--ink),0.078)}
#nav .wrap{display:flex;align-items:center;justify-content:space-between;width:100%}
.wordmark{font-family:"League Gothic",Impact,sans-serif;font-size:28px;letter-spacing:.02em;line-height:1;text-transform:uppercase}
#nav ul{display:flex;gap:28px;list-style:none;font-size:14px;color:var(--mute)}
#nav ul a:hover{color:var(--white)}
#nav .right{display:flex;gap:10px;align-items:center}
.pill{font-size:13px;padding:9px 16px;border-radius:999px;background:var(--pillbg);border:1px solid rgba(var(--ink),0.104)}
html.is-dark .shot,html.is-dark .doc{box-shadow:0 30px 90px rgba(0,0,0,.6)}
html.is-dark .closing .grain{opacity:.05}
html.is-dark .gridbg{opacity:.8}
html,body,.gridbg,.shot,.shot .hd,.card,.doc,.facts-card,.score,.score .row,.recline,.rule,.compile,.diagram .box,.diagram .in span,
table.rec td,table.rec th,.chapter .txt li,footer,.pill,.chip,.poster,.doc .cl,.doc .stamp,.tag,h1,h2,h3,p,span,b,small,a,td,th,li{
  transition:background-color .8s ease,color .8s ease,border-color .8s ease,box-shadow .8s ease;
}
#nav .menu .has-sub>a{display:inline-flex;align-items:center;gap:6px}
.chev{width:6px;height:6px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:rotate(45deg) translateY(-2px);opacity:.7}
#nav .sub{position:absolute;left:-16px;top:calc(100% + 14px);display:none;gap:36px;padding:18px 22px;border-radius:12px;background:var(--panel,#0b0a14);border:1px solid var(--hair);box-shadow:0 24px 60px rgba(0,0,0,.25);white-space:nowrap}
#nav .menu li:hover .sub,#nav .menu li:focus-within .sub{display:flex}
#nav .sub:before{content:"";position:absolute;left:0;right:0;top:-16px;height:16px}
#nav .sub .col{display:flex;flex-direction:column;gap:6px}
#nav .sub b{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--mute2);font-weight:500;margin-bottom:4px}
#nav .sub a{font-size:13px;color:var(--white);padding:3px 0}
#nav .sub a:hover{color:var(--purple)}
.burger{display:none;width:40px;height:40px;border:0;background:transparent;cursor:pointer;position:relative}
.burger span{position:absolute;left:10px;right:10px;height:2px;background:var(--white);transition:transform .25s var(--ease-out),top .25s var(--ease-out)}
.burger span:first-child{top:14px}.burger span:last-child{top:24px}
#nav.open .burger span:first-child{top:19px;transform:rotate(45deg)}
#nav.open .burger span:last-child{top:19px;transform:rotate(-45deg)}
#nav .mobile{display:none}
footer a:hover{color:var(--white)}

footer{border-top:1px solid rgba(var(--ink),0.091);padding:44px 0 36px;font-size:13px;color:var(--mute)}
footer .wrap{display:grid;grid-template-columns:1.6fr repeat(4,1fr);gap:30px}
footer ul{list-style:none;display:grid;gap:8px;margin-top:10px}
footer b{color:var(--white);font-weight:500}
footer .small{grid-column:1/-1;margin-top:26px;font-size:12px;color:var(--mute2);display:flex;justify-content:space-between}

/* nav shell: fixed bar, dropdown, burger, mobile sheet */
#nav{
  position:fixed;top:0;left:0;right:0;z-index:50;height:80px;
  display:flex;align-items:center;transition:height .24s var(--ease-io),background .24s;
}
#nav .menu li{position:relative}
@media (max-width:1100px){
  #nav .menu{gap:18px}
}
@media (max-width:980px){
  #nav{height:60px}#nav.condensed{height:56px}
  #nav .menu{display:none}
  #nav .right .pill,#nav .right .btn{display:none}
  .burger{display:block}
  #nav.open{background:var(--page)!important;backdrop-filter:none;height:100vh;align-items:flex-start;overflow:auto;flex-direction:column}
  #nav.open .wrap{height:60px;flex:none}
  #nav.open .mobile{display:block;width:100%;padding:8px 22px 40px}
  .mgroup{padding:16px 0;border-top:1px solid var(--hair)}
  .mgroup b{display:block;font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--mute2);font-weight:500;margin-bottom:10px}
  .mgroup a{display:block;font-size:18px;padding:8px 0}
  .mcta{display:flex;gap:10px;padding-top:24px}
  .mcta a{flex:1;justify-content:center;text-align:center}
  footer .wrap{grid-template-columns:1fr 1fr;gap:24px}
}
@media (max-width:560px){
  footer .wrap{grid-template-columns:1fr 1fr}
  footer .small{flex-direction:column;gap:8px}
}
#nav .menu a.on,#nav .sub a.on,footer a.on{color:var(--accent-text)}