:root{--ink:#111820;
  --mint:#4cf2be;
  --steel:#667584;
  --paper:#f5f7fa;
  --rule:#c6cfd6;
  --muted:#485968;
  --mono:Consolas,"Liberation Mono",monospace;
  color:var(--ink);
  background:var(--paper);
  font:16px/1.5 "Segoe UI Variable Text","Segoe UI",Arial,sans-serif}

*{box-sizing:border-box}
body{margin:0}
a{color:inherit}
button,input{font:inherit;
  color:inherit}
button{cursor:pointer}
button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #087a60;
  outline-offset:4px}
.wrap{width:min(1440px,100%);
  margin:auto;
  padding-inline:clamp(20px,4.6vw,70px)}
header{border-bottom:1px solid var(--rule)}
header .wrap,footer .wrap,.row{display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px}
header .wrap{min-height:74px}
.brand{font-size:clamp(24px,2.3vw,35px);
  font-weight:770;
  letter-spacing:-.07em;
  line-height:1}
.dot{color:var(--mint)}
nav{display:flex;
  align-items:center;
  gap:26px}
nav a,.jump{font-size:.88rem;
  font-weight:620;
  text-underline-offset:4px}
.preview{color:var(--muted);
  font:12px var(--mono);
  display:flex;
  gap:8px;
  align-items:center}
.preview::before{content:"";
  width:7px;
  height:7px;
  border:1px solid var(--steel);
  border-radius:50%}
.hero{display:grid;
  grid-template-columns:minmax(0,.95fr) minmax(0,1.05fr);
  gap:clamp(24px,3vw,46px);
  align-items:center;
  padding-block:clamp(35px,5.5vw,78px)}
h1,h2,h3,p,figure{margin:0}
h1,h2{font-family:"Segoe UI Variable Display","Segoe UI",Arial,sans-serif;
  font-weight:770;
  letter-spacing:-.067em;
  line-height:.98}
h1{font-size:clamp(54px,5.5vw,83px)}
h1 span{display:block}
.headline p{font-size:clamp(18px,1.55vw,24px);
  line-height:1.42;
  letter-spacing:-.02em;
  color:var(--muted);
  max-width:32ch;
  margin:22px 0 26px}
.jump{display:inline-flex;
  align-items:center;
  gap:21px;
  background:var(--mint);
  text-decoration:none;
  padding:13px 18px;
  border-radius:3px}
.jump span{font-size:1.12rem}

.workbench{min-width:0;
  scroll-margin-top:1rem}
.frame{background-color:#e6ebef;
  background-image:radial-gradient(#abb9c3 .75px,transparent .9px);
  background-size:9px 9px;
  padding:clamp(18px,2.3vw,38px) clamp(12px,1.9vw,30px);
  border:1px solid var(--rule);
  position:relative;
  border-radius:3px}
.console{background:var(--ink);
  color:var(--paper);
  border-radius:7px;
  box-shadow:0 13px 24px -15px #0b1627b3;
  overflow:hidden}
.console-head{padding:12px 18px;
  border-bottom:1px solid #3d4a54}
.console h2{font-size:14px;
  font-weight:650;
  letter-spacing:-.025em;
  line-height:1.3}
.window-dots{display:inline-flex;
  gap:4px}
.window-dots i{width:4px;
  height:4px;
  border-radius:50%;
  background:#a6b6c2}
.scene{padding:18px;
  min-height:243px;
  background:linear-gradient(130deg,#1b2830 0,var(--ink) 64%)}
[hidden]{display:none!important}
.scene-label{color:#adc1cb;
  font:12px var(--mono);
  display:flex;
  justify-content:space-between;
  margin-bottom:14px}
.mock-input,.sheet,.ticket,.route-box{border-radius:4px}
.mock-input{background:#25343d;
  border:1px solid #475662;
  display:flex;
  align-items:center;
  gap:12px;
  padding:9px 12px;
  font-size:14px}
.icon{width:19px;
  height:19px;
  flex:none;
  fill:none;
  stroke:currentColor;
  stroke-width:1.7;
  stroke-linecap:round;
  stroke-linejoin:round}
.mock-input .icon,.route-arrow{color:var(--mint)}
.sheet{background:var(--paper);
  color:var(--ink);
  border-left:4px solid var(--mint);
  margin-top:12px;
  padding:12px 15px}
.sheet small,.ticket small,.route-box small{display:block;
  font:11px/1.45 var(--mono);
  color:var(--muted)}
.sheet strong,.route-box strong{display:block;
  font-size:clamp(16px,1.4vw,22px);
  line-height:1.25;
  letter-spacing:-.035em;
  margin:3px 0}
.sheet p,.ticket p{font-size:13px;
  line-height:1.4}
.tag{display:inline-block;
  border:1px solid #576a73;
  border-radius:3px;
  padding:3px 8px;
  font:11px/1.3 var(--mono);
  color:#d2e1e7;
  margin-top:9px}
.stack{display:grid;
  grid-template-columns:1fr 1.1fr;
  gap:9px}
.ticket{padding:12px;
  background:#263640;
  border:1px solid #46565e}
.ticket small{color:#acd9ce;
  margin-bottom:6px}
.ticket.light{background:var(--paper);
  color:var(--ink);
  border:0}
.ticket.light small{color:var(--muted)}
.review{display:flex;
  align-items:center;
  gap:8px;
  margin-top:11px;
  font-size:12px;
  color:var(--mint)}
.review .icon{width:16px;
  height:16px}
.routes{display:grid;
  grid-template-columns:1fr 22px 1fr;
  align-items:center;
  gap:4px}
.route-box{padding:11px;
  background:#273740;
  border:1px solid #536572}
.route-box small{color:#c4d3db}
.route-box strong{font-size:16px}
.route-box.end{background:#dff9ee;
  border-color:var(--mint);
  color:var(--ink)}
.route-box.end small{color:#36594b}
.routing-rule{margin:0 0 12px;
  color:#c8d5db;
  font-size:13px}
.route-arrow{text-align:center}
.controls{display:flex;
  border-top:1px solid #3c4c58;
  padding:5px;
  gap:3px}
.controls button{width:33.33%;
  padding:9px 3px;
  border:0;
  background:transparent;
  color:#bfccd6;
  font-size:13px;
  border-radius:3px}
.controls button[aria-pressed=true]{color:var(--ink);
  background:var(--mint);
  font-weight:650}
.controls button:focus-visible{outline:2px solid white;
  outline-offset:-3px}
.controls button[aria-pressed=true]:focus-visible{outline-color:var(--ink)}
.caption{color:var(--muted);
  font-size:12px;
  display:flex;
  justify-content:space-between;
  gap:12px;
  margin:9px 0 0}
.caption span:last-child{font-family:var(--mono)}
.play .arrive{animation:arrive .52s ease-out both;
  animation-delay:var(--delay,0s)}
.play .typed{animation:type .78s steps(24,end) both;
  clip-path:inset(0)}
.play .route-arrow{animation:route .6s ease-out .46s both}
@keyframes arrive{from{transform:translateY(7px);
  opacity:0}
to{transform:translateY(0);
  opacity:1}
}
@keyframes type{from{clip-path:inset(0 100% 0 0)}
to{clip-path:inset(0)}
}
@keyframes route{from{transform:translateX(-9px);
  opacity:0}
to{transform:translateX(0);
  opacity:1}
}

.model{border-top:1px solid var(--rule);
  padding-block:clamp(32px,4.4vw,65px)}
.intro{display:grid;
  grid-template-columns:1.15fr 1fr;
  gap:35px;
  align-items:end;
  margin-bottom:30px}
.intro h2{font-size:clamp(36px,4vw,62px);
  max-width:15ch}
.intro p{max-width:55ch;
  color:var(--muted)}
.calc{display:grid;
  grid-template-columns:1.18fr 1fr;
  border:1px solid var(--rule);
  border-radius:5px;
  overflow:hidden;
  background:white}
.assumptions,.result{padding:clamp(18px,2.5vw,37px)}
.assumptions h3,.result h3{font-size:17px;
  font-weight:650;
  letter-spacing:-.025em}
.presets{display:flex;
  gap:4px;
  flex-wrap:wrap}
.presets button{border:1px solid var(--rule);
  border-radius:3px;
  background:var(--paper);
  padding:5px 9px;
  font-size:12px}
.presets button[aria-pressed=true]{color:white;
  background:var(--ink);
  border-color:var(--ink)}
.fields{margin-top:20px;
  display:grid;
  gap:12px 20px;
  grid-template-columns:repeat(2,minmax(0,1fr))}
label{display:block;
  font-size:13px;
  color:var(--muted)}
input{display:block;
  width:100%;
  min-height:39px;
  border:1px solid #a7b3bc;
  border-radius:2px;
  padding:6px 9px;
  background:white;
  margin-top:3px;
  font-variant-numeric:tabular-nums;
  font-weight:600}
input:invalid{border-color:#aa412a}
.hint{margin-top:13px;
  color:var(--muted);
  font-size:12px}
.result{background:var(--ink);
  color:var(--paper);
  display:flex;
  flex-direction:column;
  justify-content:center}
.result h3{color:#c6d4dc}
.result output{display:block;
  font-size:clamp(44px,5.5vw,80px);
  letter-spacing:-.065em;
  line-height:1.15;
  font-weight:720;
  color:var(--mint);
  overflow-wrap:anywhere}
.result.loss output{color:#ffbfae}
.result p{font-size:14px;
  color:#d6e1e7}
.result .math{border-top:1px solid #475663;
  margin-top:20px;
  padding-top:15px;
  line-height:1.6;
  font-family:var(--mono);
  font-size:12px}
.sr{position:absolute;
  width:1px;
  height:1px;
  padding:0;
  margin:-1px;
  overflow:hidden;
  clip:rect(0,0,0,0);
  white-space:nowrap;
  border:0}
footer{background:var(--ink);
  color:var(--paper);
  padding:25px 0}
footer .brand{font-size:23px}
footer small{font-size:12px;
  color:#bcc9d1}

@media(max-width:920px){.hero{grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr);
  gap:20px}
.scene{padding:13px}
.frame{padding:12px}
.caption{font-size:11px}
.assumptions .row{align-items:flex-start;
  flex-wrap:wrap}
h1{font-size:clamp(47px,5.6vw,56px)}
}

@media(max-width:730px){.hero,.intro,.calc{grid-template-columns:minmax(0,1fr)}
.hero{gap:28px}
.headline p{max-width:39ch}
.headline h1{font-size:clamp(44px,8.5vw,63px)}
.scene{min-height:220px;
  padding:16px}
.intro{gap:13px}
.intro h2{max-width:20ch}
.frame{padding:18px}
header .wrap{min-height:61px}
.preview{font-size:11px}
nav a{display:none}
.result{min-height:195px}
.caption{font-size:12px}
.assumptions .row{align-items:center}
}

@media(max-width:400px){.frame{padding:8px}
.scene{padding:12px;
  min-height:223px}
.caption span:last-child{display:none}
.fields{gap:12px}
.hero{padding-top:29px}
.result output{font-size:45px}
.brand{font-size:25px}
.stack{gap:6px}
.ticket{padding:8px}
.route-box{padding:8px}
footer .wrap{flex-wrap:wrap}
}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;
  transition:none!important}
}

:root { --space:clamp(45px,6vw,90px); --deep:#152f2d; }
body { font-family:Inter, "Segoe UI Variable Text","Segoe UI",Arial,sans-serif; }
a { text-underline-offset:.22em; }
.brand { text-decoration:none; font-weight:800; }
.skip { position:absolute; top:-100px; left:8px; padding:8px; background:white; z-index:20; }
.skip:focus { top:8px; }
header .wrap { gap:30px; min-height:74px; }
header nav { gap:clamp(12px,2vw,32px); margin-left:auto; }
header nav a { display:inline; text-decoration:none; }
header nav a:hover,header nav a[aria-current=page] { text-decoration:underline; text-decoration-thickness:2px; }
.btn, .jump { display:inline-flex; align-items:center; justify-content:center; gap:14px; background:var(--mint); color:var(--ink); border:1px solid var(--mint); border-radius:3px; text-decoration:none; padding:12px 18px; font-weight:700; font-size:15px; }
.btn:hover,.jump:hover { background:#83ffda; }
.button-row { display:flex; align-items:center; flex-wrap:wrap; gap:21px; }
.quiet-link { font-weight:640; text-decoration-thickness:1px; }
.kicker,.ordinal,.crumb { font:12px/1.5 var(--mono); color:var(--muted); letter-spacing:.06em; }
.headline h1 { font-size:clamp(48px,5.6vw,90px); }
.headline .kicker { margin:0 0 19px; font:12px/1.5 var(--mono); color:#425563; }
.hero { padding-block:clamp(45px,5.8vw,88px); grid-template-columns:minmax(0,1fr) minmax(0,1fr); }
.frame { padding:clamp(12px,2.6vw,42px); background-color:#e6edf0; }
.workbench figure { margin:0; }
.band { padding-block:var(--space); border-top:1px solid var(--rule); }
.band h2,.content h2,.form-area h2,.article-links h2 { font-size:clamp(32px,3.9vw,59px); line-height:1.02; }
.capabilities { padding:clamp(33px,4vw,62px) 0; border-top:1px solid var(--rule); }
.capabilities h2 { font-size:clamp(33px,3.8vw,60px); margin:0 0 28px; }
.service-grid { display:grid; grid-template-columns:repeat(4,minmax(0,1fr)); gap:22px; }
.service-card { display:flex; flex-direction:column; border-left:1px solid var(--rule); padding-left:16px; color:inherit; text-decoration:none; }
.service-card .ordinal { color:#08735c; }
.service-card h3 { font-size:clamp(22px,2.1vw,35px); letter-spacing:-.05em; line-height:1.15; margin:9px 0; }
.service-card p,.linecard p { color:var(--muted); margin-bottom:20px; max-width:39ch; }
.service-card .card-link { margin-top:auto; font-weight:660; font-size:14px; }
.service-card:hover .card-link { text-decoration:underline; }
.story { background:var(--ink); color:#f5f7fa; }
.story .wrap,.split { display:grid; grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr); gap:clamp(30px,6vw,92px); }
.story .kicker { color:#96b6b1; }
.story h2 { margin:12px 0 20px; }
.story ol { list-style:none; padding:0; margin:0; }
.story li { padding:18px 0; border-top:1px solid #3d5158; display:grid; grid-template-columns:35px 1fr; gap:8px; }
.story .num { font:13px var(--mono); color:var(--mint); }
.story h3 { font-size:19px; margin-bottom:5px; }
.story p { color:#c2d2dc; max-width:48ch; }
.linecard { display:block; text-decoration:none; border-top:1px solid var(--rule); padding:18px 0; }
.linecard h3 { font-size:23px; letter-spacing:-.035em; }
.linecard:hover h3 { text-decoration:underline; }
.linecard p { margin:5px 0 0; }
.ending { background:#d7f5eb; }
.ending .wrap { display:flex; align-items:center; justify-content:space-between; gap:22px; }
.ending h2 { max-width:18ch; }
.ending .btn { background:var(--ink); color:white; border-color:var(--ink); }
footer .wrap { align-items:flex-start; flex-wrap:wrap; padding-block:12px; }
footer .footlinks { display:flex; gap:16px; flex-wrap:wrap; align-items:center; }
footer a,footer button { font-size:13px; color:#d6e3eb; }
footer button,.text-button { padding:0; border:0; background:none; text-decoration:underline; }
footer small { display:block; margin-top:12px; }
.consent { border:1px solid var(--rule); max-width:440px; padding:18px 20px; background:white; border-radius:5px; box-shadow:0 6px 28px #11182025; position:fixed; bottom:14px; right:14px; z-index:8; }
.consent p { font-size:14px; margin:4px 0 10px; color:var(--muted); }
.consent .btn { padding:7px 12px; font-size:13px; background:var(--paper); border:1px solid var(--rule); }
.consent .row { justify-content:flex-start; gap:8px; }
.subhero { padding-block:clamp(38px,6vw,88px); border-bottom:1px solid var(--rule); }
.subhero h1 { margin:18px 0 22px; max-width:17ch; font-size:clamp(42px,5.7vw,87px); }
.subhero p { font-size:clamp(18px,1.65vw,25px); color:var(--muted); max-width:52ch; margin-bottom:22px; }
.crumb a { text-decoration:underline; }.crumb span { padding-inline:8px; }
.content-grid { display:grid; grid-template-columns:repeat(3,minmax(0,1fr)); gap:26px; margin-top:30px; }
.content-grid article { padding-top:14px; border-top:2px solid var(--ink); }
.content-grid h3 { font-size:24px; letter-spacing:-.04em; margin:9px 0; }
.content-grid p,.lede { color:var(--muted); max-width:60ch; }
.content-copy { max-width:820px; margin:0 auto; }
.content-copy p { margin:12px 0 25px; font-size:18px; color:var(--muted); }
.content-copy h2 { font-size:clamp(27px,3vw,40px); margin-top:36px; }
.content-copy ul { padding-left:20px; }
.form-area form { background:white; border:1px solid var(--rule); padding:clamp(20px,3vw,44px); }
.form-area label { font-size:14px; font-weight:600; margin-bottom:16px; }
.form-area :is(input,textarea,select) { font-family:inherit; font-size:16px; border:1px solid #97a7b2; padding:10px; width:100%; border-radius:3px; color:var(--ink); background:white; display:block; margin-top:5px; }
.form-area input:invalid:not(:focus) { border-color:#97a7b2; }
.form-area textarea { min-height:120px; resize:vertical; }
.form-area .trap { position:absolute; left:-20000px; }
.form-note,.form-status { font-size:14px; margin:12px 0; color:var(--muted); }
.form-status.error { color:#993821; }
.form-status.error:not(:empty) { padding:12px 15px; border-left:3px solid #993821; background:#fff3ed; }
.receipt-area { padding-block:clamp(32px,7vw,100px); }
.receipt-card { max-width:740px; margin:auto; padding:clamp(25px,6vw,70px); border:1px solid var(--rule); border-top:5px solid #168466; border-radius:6px; background:white; }
.receipt-check { display:grid; place-items:center; width:58px; height:58px; border-radius:50%; background:var(--mint); color:#10261f; }
.receipt-label { margin:26px 0 8px; font:600 14px var(--mono); color:#306354; }
.receipt-card h1 { margin:0; font-size:clamp(41px,6vw,76px); line-height:1.02; letter-spacing:-.055em; }
.receipt-card h1:focus { outline:none; }
.receipt-detail { max-width:44ch; margin:20px 0 30px; font-size:clamp(17px,2vw,21px); color:var(--muted); }
.contact-side h1 { max-width:12ch; margin-bottom:18px; }
.contact-side p { font-size:19px; color:var(--muted); max-width:39ch; margin-bottom:30px; }
.contact-side ul { list-style:none; padding:0; }
.contact-side li { border-top:1px solid var(--rule); padding:10px 0; max-width:360px; font-weight:640; }
header .menu-btn { display:none; }.form-area .crumb { display:block; margin-bottom:22px; }
@media(max-width:800px){.service-grid,.content-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.split,.story .wrap{gap:28px}.service-grid{row-gap:24px}header nav{gap:12px}header nav a{font-size:13px}}
@media(max-width:730px){.hero,.split,.story .wrap{grid-template-columns:1fr}.ending .wrap{align-items:flex-start;flex-direction:column}.hero .headline h1{font-size:clamp(48px,9.6vw,68px)}.consent{max-width:min(400px,calc(100vw - 24px));right:12px;bottom:10px}.contact-side ul{display:none}.service-card p{font-size:15px}.ending h2{max-width:20ch}}
@media(max-width:650px){header .wrap{gap:12px;min-height:65px;flex-wrap:wrap;padding-block:12px}header nav{order:3;width:100%;padding:10px 0 3px;border-top:1px solid var(--rule);justify-content:space-between;flex-wrap:wrap}header nav a{font-size:14px}header .menu-btn{display:block;margin-left:auto;border:0;background:transparent;font-weight:630;font-size:14px}html.js header nav:not(.open){display:none}header .btn{padding:7px 10px;font-size:14px}.frame{padding:13px}.content-grid{grid-template-columns:1fr}.story .wrap{gap:16px}}
@media(max-width:390px){.service-grid{gap:16px 10px}.service-card{padding-left:9px}.service-card h3{font-size:20px}.btn{font-size:14px}.button-row{gap:15px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;scroll-behavior:auto!important}}

/* Practical worksheets inside the owner guides. */
.owner-guide .subhero h1{max-width:23ch}
.owner-guide .copy-log{max-width:100%;overflow-x:auto;padding:18px;background:var(--ink);color:#d5fff2;border-radius:4px;font:14px/1.7 ui-monospace,monospace;tab-size:2}
.owner-guide .field-notes{margin:22px 0 30px;border-bottom:1px solid var(--rule)}
.owner-guide .field-notes dt{border-top:1px solid var(--rule);padding:15px 0 4px;font-size:1.05rem;font-weight:680}
.owner-guide .field-notes dd{margin:0 0 15px;color:var(--muted);line-height:1.6}
.owner-guide .guide-steps{padding-left:1.5rem;line-height:1.6}
.owner-guide .guide-steps li{padding:0 0 .8rem .25rem}
.owner-guide .guide-related{border-top:1px solid var(--rule);padding-top:20px;font-weight:650}