/* osact.io landing page. Tokens are the OSACT palette (BRAND2 sheet, light ground);
   the hero drawing uses the dark ground. Fonts: DM Sans, JetBrains Mono (SIL OFL). */
@font-face{font-family:"DM Sans";src:url("fonts/DMSans.woff2") format("woff2");font-weight:100 1000;font-display:swap}
@font-face{font-family:"JetBrains Mono";src:url("fonts/JetBrainsMono.woff2") format("woff2");font-weight:100 800;font-display:swap}

:root{
  color-scheme:light;
  --bg:#ffffff; --surface:#f6f6f4; --raised:#ffffff; --field:#fafaf8;
  --line:#cfd0d6; --line-soft:#e6e7ea;
  --text:#101115; --muted:#5a5c66; --label:#474952; --focus:#2452c7;
  --ring-0:#c97a08; --ring-1:#e2433e; --ring-2:#0fa192; --ring-3:#4f93dc; --ring-4:#8a8c93;
  --ring-0-ink:#8f5200; --ring-1-ink:#b82a26; --ring-2-ink:#0a6f65; --ring-3-ink:#235f9f; --ring-4-ink:#5f6169;
  /* the dark ground of the hero drawing */
  --d-bg:#090a0b; --d-surface:#101115; --d-line:#343640; --d-text:#f2f2f5; --d-muted:#a7a8b1;
  --d-ring-0:#ef9f27; --d-ring-1:#ef5a55; --d-ring-2:#14b8a6; --d-ring-3:#85b7eb; --d-ring-4:#8a8c93;
  --sans:"DM Sans",-apple-system,BlinkMacSystemFont,"Helvetica Neue",Arial,sans-serif;
  --mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,monospace;
  --wrap:1180px; --gut:clamp(20px,4vw,48px);
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:84px;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--sans);font-size:17px;line-height:1.6;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
h1,h2,h3,p,ul,ol,dl,dd,figure{margin:0}
ul,ol{padding:0;list-style:none}
a{color:inherit}
img,svg{display:block;max-width:100%}
:focus-visible{outline:2px solid var(--focus);outline-offset:3px;border-radius:4px}
.skip{position:absolute;left:-9999px;top:8px;background:var(--text);color:#fff;padding:10px 14px;border-radius:8px;z-index:50}
.skip:focus{left:12px}
.wrap{max-width:var(--wrap);margin:0 auto;padding:0 var(--gut)}

/* type */
.mono{font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;font-weight:500;color:var(--label)}
h1{font-size:clamp(2.6rem,6.2vw,4.9rem);line-height:1.02;letter-spacing:-.03em;font-weight:500}
h2{font-size:clamp(1.9rem,3.6vw,3rem);line-height:1.08;letter-spacing:-.024em;font-weight:500;max-width:18ch}
h3{font-size:1.18rem;line-height:1.3;letter-spacing:-.012em;font-weight:600}
.lede{font-size:clamp(1.12rem,1.5vw,1.3rem);line-height:1.5;color:var(--text);max-width:36ch}
.body{color:var(--muted);max-width:58ch}
.kicker{display:flex;align-items:center;gap:10px;margin-bottom:22px}
.kicker::before{content:"";width:22px;height:2px;background:var(--k,var(--ring-2))}

/* buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:0 20px;border-radius:999px;
  font:600 15px/1 var(--sans);text-decoration:none;border:1px solid var(--text);background:var(--text);color:#fff;cursor:pointer;
  transition:background .18s,color .18s,border-color .18s}
.btn:hover{background:#2a2c35;border-color:#2a2c35}
.btn.ghost{background:transparent;color:var(--text);border-color:var(--line)}
.btn.ghost:hover{border-color:var(--text);background:transparent}
.btn[disabled]{opacity:.45;cursor:not-allowed}
.btn-row{display:flex;flex-wrap:wrap;gap:12px}

/* nav */
.nav{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.86);backdrop-filter:saturate(1.4) blur(14px);
  -webkit-backdrop-filter:saturate(1.4) blur(14px);border-bottom:1px solid var(--line-soft)}
.nav .wrap{display:flex;align-items:center;gap:28px;height:68px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-weight:600;font-size:21px;letter-spacing:-.03em}
.brand svg{width:30px;height:30px}
.nav nav{margin-left:auto}
.nav ul{display:flex;gap:26px}
.nav li a{text-decoration:none;font-size:15px;color:var(--label);padding:10px 0;display:block}
.nav li a:hover{color:var(--text)}
.nav .btn{min-height:40px;padding:0 16px;font-size:14px}
@media (max-width:900px){.nav ul{display:none}.nav .btn{margin-left:auto}}

/* hero */
.hero{padding:clamp(44px,7vw,96px) 0 clamp(56px,7vw,104px)}
.hero .wrap{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:clamp(32px,5vw,72px);align-items:center}
.status{display:inline-flex;align-items:center;gap:10px;padding:7px 12px 7px 10px;border:1px solid var(--line);border-radius:999px;margin-bottom:28px}
.status i{width:8px;height:8px;border-radius:50%;background:var(--ring-2)}
.hero .lede{margin-top:26px}
.hero .body{margin-top:16px;font-size:16px}
.hero .btn-row{margin-top:34px}
@media (max-width:980px){.hero .wrap{grid-template-columns:1fr}}

/* the hero drawing (dark ground) */
.field{background:var(--d-bg);color:var(--d-text);border-radius:18px;padding:18px 18px 20px;position:relative;overflow:hidden}
.field-top{display:flex;justify-content:space-between;align-items:center;gap:12px}
.field .mono{color:var(--d-muted);font-size:11px}
.field-sq{position:relative;aspect-ratio:1/1;max-width:560px;margin:-8px auto -4px}
.field-sq svg{position:absolute;inset:0;width:100%;height:100%}
.ring{fill:none;stroke-width:2.4;stroke-linejoin:round;opacity:.5;animation:stage 12.5s linear infinite;animation-delay:calc(var(--n)*2.5s)}
.spoke{stroke:var(--d-line);stroke-width:1}
.node{fill:var(--d-bg);stroke:var(--d-ring-4);stroke-width:1.6}
.svc{position:absolute;font-family:var(--mono);font-size:clamp(10px,1.25vw,12.5px);letter-spacing:.06em;text-transform:uppercase;color:var(--d-text);white-space:nowrap;line-height:1}
.svc.e{transform:translate(-100%,-50%)}.svc.s{transform:translate(0,-50%)}
.svc.n{transform:translate(-50%,-100%)}.svc.b{transform:translate(-50%,0)}
.core{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);text-align:center}
.core b{display:block;font-size:clamp(22px,3.4vw,34px);font-weight:600;letter-spacing:-.04em;line-height:1}
.core span{display:block;margin-top:7px;font-family:var(--mono);font-size:10px;letter-spacing:.14em;text-transform:uppercase;color:var(--d-muted)}
.stages{display:flex;justify-content:center;flex-wrap:wrap;gap:6px 4px;margin-top:6px}
.stages li{display:flex;align-items:center;font-family:var(--mono);font-size:clamp(10px,1.2vw,12px);letter-spacing:.06em;text-transform:uppercase}
.stages li span{padding:6px 9px;border-radius:999px;border:1px solid transparent;color:var(--d-muted);
  animation:chip 12.5s linear infinite;animation-delay:calc(var(--n)*2.5s)}
.stages li + li::before{content:"\2192";color:var(--d-line);margin-right:4px}
@keyframes stage{0%,17%{opacity:1;stroke-width:3.4}21%,100%{opacity:.5;stroke-width:2.4}}
@keyframes chip{0%,17%{color:var(--c);border-color:var(--c)}21%,100%{color:var(--d-muted);border-color:transparent}}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .ring{animation:none;opacity:1}
  .stages li span{animation:none;color:var(--c)}
}

/* sections */
section{padding:clamp(64px,9vw,128px) 0}
.band{background:var(--surface);border-top:1px solid var(--line-soft);border-bottom:1px solid var(--line-soft)}
.head{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:24px clamp(32px,5vw,72px);align-items:end;margin-bottom:clamp(36px,5vw,64px)}
.head .body{justify-self:start}
@media (max-width:820px){.head{grid-template-columns:1fr}}

/* services */
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));border-top:1px solid var(--line);border-left:1px solid var(--line)}
.card{padding:28px 26px 26px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);background:var(--raised);display:flex;flex-direction:column;gap:14px}
.card svg{width:30px;height:30px;stroke:var(--text);fill:none;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round}
.card p{color:var(--muted);font-size:15.5px;line-height:1.55}
.card .state{margin-top:auto;padding-top:8px}
@media (max-width:980px){.grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:620px){.grid{grid-template-columns:1fr}}
.state{display:flex;align-items:flex-start;gap:9px;font-family:var(--mono);font-size:11px;letter-spacing:.04em;text-transform:uppercase;color:var(--label);line-height:1.45}
.state i{flex:none;width:10px;height:10px;border-radius:50%;margin-top:3px;border:1.5px solid var(--text)}
.state.preview i{background:var(--text)}
.state.building i{background:linear-gradient(90deg,var(--text) 50%,transparent 50%)}
.state.external i{background:transparent;border-style:dashed}
.legend{display:flex;flex-wrap:wrap;gap:10px 26px;margin-top:22px}

/* the loop */
.loop{display:grid;grid-template-columns:minmax(0,5fr) minmax(0,6fr);gap:clamp(32px,6vw,88px);align-items:start}
.loop-side{position:sticky;top:104px}
.loop-side h2{margin-bottom:22px}
.steps{counter-reset:s;border-top:1px solid var(--line)}
.steps li{counter-increment:s;display:grid;grid-template-columns:64px minmax(0,1fr);gap:8px 0;padding:26px 0;border-bottom:1px solid var(--line)}
.steps li::before{content:"0" counter(s);font-family:var(--mono);font-size:13px;font-weight:600;color:var(--ink);padding-top:5px}
.steps h3{font-size:1.5rem;font-weight:500;letter-spacing:-.025em;display:flex;align-items:center;gap:12px}
.steps h3::after{content:"";flex:none;width:14px;height:14px;border-radius:50%;border:2.4px solid var(--c)}
.steps p{grid-column:2;color:var(--muted)}
.trust{margin-top:34px;padding:22px 24px;border-left:3px solid var(--text);background:var(--raised);font-size:1.12rem;line-height:1.45;font-weight:500;letter-spacing:-.012em}
@media (max-width:900px){.loop{grid-template-columns:1fr}.loop-side{position:static}}

/* the illustrative record */
.record{margin-top:clamp(40px,6vw,72px);border:1px solid var(--line);border-radius:14px;background:var(--raised);overflow:hidden}
.record-top{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;padding:14px 20px;border-bottom:1px solid var(--line-soft);background:var(--field)}
.record ol{display:grid;grid-template-columns:repeat(4,minmax(0,1fr))}
.record li{padding:22px 20px 24px;border-right:1px solid var(--line-soft)}
.record li:last-child{border-right:0}
.record li b{display:block;margin:10px 0 6px;font-size:1.02rem;font-weight:600;letter-spacing:-.01em}
.record li p{color:var(--muted);font-size:15px;line-height:1.5}
.record .note{padding:14px 20px;border-top:1px solid var(--line-soft);color:var(--muted);font-size:14.5px}
@media (max-width:860px){.record ol{grid-template-columns:1fr}.record li{border-right:0;border-bottom:1px solid var(--line-soft)}.record li:last-child{border-bottom:0}}

/* local AI split */
.split{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:0;border:1px solid var(--line);border-radius:14px;overflow:hidden;background:var(--raised)}
.split > div{padding:28px 28px 30px}
.split > div + div{border-left:1px solid var(--line)}
.split h3{margin:12px 0 14px}
.tags{display:flex;flex-wrap:wrap;gap:8px}
.tags li{font-size:14.5px;padding:7px 12px;border:1px solid var(--line);border-radius:999px;color:var(--label);background:var(--field)}
.split p{color:var(--muted);font-size:15.5px;margin-top:16px}
@media (max-width:760px){.split{grid-template-columns:1fr}.split > div + div{border-left:0;border-top:1px solid var(--line)}}
.three{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:clamp(20px,3vw,44px);margin-top:clamp(36px,5vw,60px)}
.three li{padding-top:18px;border-top:2px solid var(--text)}
.three p{color:var(--muted);font-size:16px}
.three .mono{display:block;margin-bottom:10px}
@media (max-width:760px){.three{grid-template-columns:1fr}}

/* control */
.four{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:clamp(28px,4vw,56px) clamp(32px,5vw,72px)}
.four li{display:grid;grid-template-columns:44px minmax(0,1fr);gap:6px 0}
.four li .mono{padding-top:5px;color:var(--ring-2-ink)}
.four p{grid-column:2;color:var(--muted)}
@media (max-width:720px){.four{grid-template-columns:1fr}}

/* journey */
.journey{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));position:relative}
.journey::before{content:"";position:absolute;left:0;right:0;top:9px;height:2px;background:var(--line)}
.journey li{position:relative;padding:34px 22px 0 0}
.journey li::before{content:"";position:absolute;left:0;top:0;width:20px;height:20px;border-radius:50%;background:var(--bg);border:2.4px solid var(--c)}
.band .journey li::before{background:var(--surface)}
.journey .mono{display:block;margin-bottom:8px}
.journey p{color:var(--muted);font-size:15px;margin-top:8px;line-height:1.5}
@media (max-width:900px){
  .journey{grid-template-columns:1fr}
  .journey::before{left:9px;right:auto;top:0;bottom:0;width:2px;height:auto}
  .journey li{padding:0 0 30px 44px}
}

/* access */
.access{display:grid;grid-template-columns:minmax(0,5fr) minmax(0,6fr);gap:clamp(32px,6vw,88px);align-items:start}
.paths{margin-top:30px;border-top:1px solid var(--line)}
.paths li{padding:20px 0;border-bottom:1px solid var(--line)}
.paths p{color:var(--muted);font-size:15.5px;margin-top:4px}
form{border:1px solid var(--line);border-radius:14px;background:var(--raised);padding:clamp(22px,3vw,34px)}
fieldset{border:0;padding:0;margin:0 0 22px}
legend,label{display:block;font-size:14.5px;font-weight:600;margin-bottom:8px;padding:0}
label small{font-weight:400;color:var(--muted)}
.choice{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.choice label{position:relative;margin:0;font-weight:500;border:1px solid var(--line);border-radius:10px;padding:13px 14px 13px 40px;cursor:pointer;background:var(--field);line-height:1.3}
.choice input{position:absolute;left:14px;top:15px;width:16px;height:16px;margin:0;accent-color:var(--text)}
.choice label:has(input:checked){border-color:var(--text);background:var(--raised)}
.row{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.f{margin-bottom:18px}
input[type=text],input[type=email],textarea{width:100%;font:inherit;font-size:16px;color:var(--text);background:var(--field);border:1px solid var(--line);border-radius:10px;padding:12px 14px}
textarea{min-height:112px;resize:vertical}
input:focus-visible,textarea:focus-visible{outline:2px solid var(--focus);outline-offset:1px;border-color:var(--focus)}
.form-foot{display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.msg{font-size:15px;color:var(--muted);min-height:1.4em;flex:1 1 220px}
.msg.ok{color:var(--ring-2-ink);font-weight:600}.msg.err{color:var(--ring-1-ink);font-weight:600}
.hp{position:absolute;left:-9999px;width:1px;height:1px;overflow:hidden}
@media (max-width:900px){.access{grid-template-columns:1fr}}
@media (max-width:560px){.choice,.row{grid-template-columns:1fr}}

/* faq */
.faq{display:grid;grid-template-columns:minmax(0,4fr) minmax(0,7fr);gap:clamp(32px,6vw,88px)}
details{border-bottom:1px solid var(--line)}
details:first-of-type{border-top:1px solid var(--line)}
summary{list-style:none;cursor:pointer;display:flex;justify-content:space-between;gap:20px;align-items:center;padding:22px 0;font-size:1.15rem;font-weight:500;letter-spacing:-.015em}
summary::-webkit-details-marker{display:none}
summary::after{content:"+";font-family:var(--mono);font-size:20px;color:var(--label);flex:none}
details[open] summary::after{content:"\2212"}
details p{color:var(--muted);padding:0 40px 24px 0;max-width:64ch}
@media (max-width:860px){.faq{grid-template-columns:1fr}}

/* close + footer */
.close{background:var(--d-bg);color:var(--d-text);text-align:center}
.close h2{max-width:20ch;margin:0 auto 34px}
.close .btn-row{justify-content:center}
.close .btn{background:var(--d-text);color:var(--d-bg);border-color:var(--d-text)}
.close .btn:hover{background:#fff;border-color:#fff}
.close .btn.ghost{background:transparent;color:var(--d-text);border-color:var(--d-line)}
.close .btn.ghost:hover{border-color:var(--d-text);background:transparent}
.close :focus-visible{outline-color:#b7cafa}
footer{background:var(--d-bg);color:var(--d-muted);border-top:1px solid var(--d-line);padding:34px 0 44px;font-size:14.5px}
footer .wrap{display:flex;justify-content:space-between;gap:16px 40px;flex-wrap:wrap;align-items:center}
footer .brand{color:var(--d-text);font-size:19px}
footer p{max-width:60ch}

/* the small mark (five rings), light and dark grounds */
.m-light,.brand{--m0:var(--ring-0);--m1:var(--ring-1);--m2:var(--ring-2);--m3:var(--ring-3);--m4:var(--ring-4)}
.m-dark{--m0:var(--d-ring-0);--m1:var(--d-ring-1);--m2:var(--d-ring-2);--m3:var(--d-ring-3);--m4:var(--d-ring-4)}
.brand svg{width:30px;height:30px}

@media (max-width:560px){
  .status{font-size:10.5px;letter-spacing:.05em;padding:6px 11px 6px 9px}
  .field-top span + span{display:none}
  .hero .btn-row .btn{flex:1 1 auto}
}