/* OhmPrep site styles. Dark is default, light via [data-theme="light"]. */
:root {
  --bg: #0E1417;
  --panel: #162025;
  --panel-2: #1A262C;
  --edge: #2B3A41;
  --edge-ui: #5F7881;
  --text: #F2F7F6;
  --mute: #9DB1B6;
  --accent: #22D3C0;
  --accent-ink: #0E1417;
  --link: #22D3C0;
  --spark: #FFB84A;
  --err: #FF7A6B;
  --grid: rgba(34, 211, 192, 0.07);
  --shadow: 0 1px 0 rgba(255,255,255,0.03) inset, 0 12px 32px rgba(0,0,0,0.35);
  --f-display: "Barlow Semi Condensed", "Arial Narrow", sans-serif;
  --f-body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --f-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;
  --r-input: 10px;
  --r-btn: 12px;
  --r-card: 16px;
  --gutter: 16px;
  --max: 1120px;
  color-scheme: dark;
}
:root[data-theme="light"] {
  --bg: #F2F7F6;
  --panel: #FFFFFF;
  --panel-2: #E8F0EE;
  --edge: #D2DEDB;
  --edge-ui: #4A5E64;
  --text: #0E1417;
  --mute: #4A5E64;
  --accent: #00746A;
  --accent-ink: #F2F7F6;
  --link: #00746A;
  --spark: #8A5A00;
  --err: #B3261E;
  --grid: rgba(0, 116, 106, 0.07);
  --shadow: 0 1px 2px rgba(14,20,23,0.06), 0 10px 28px rgba(14,20,23,0.07);
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--f-body);
  font-size: 17px;
  line-height: 1.6;
  overflow-x: hidden;
}
img, svg { max-width: 100%; height: auto; display: block; }
a { color: var(--link); text-underline-offset: 3px; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
::selection { background: var(--accent); color: var(--accent-ink); }

.skip { position: absolute; left: -9999px; top: 8px; z-index: 100; background: var(--accent); color: var(--accent-ink); padding: 10px 14px; border-radius: var(--r-btn); font-weight: 700; }
.skip:focus { left: 8px; }
.wrap { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 var(--gutter); }
.narrow { max-width: 760px; }
.vh { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

h1, h2, h3 { font-family: var(--f-display); font-weight: 800; line-height: 1.05; letter-spacing: 0.005em; margin: 0 0 12px; }
h1 { font-size: clamp(2.35rem, 8.6vw, 4.6rem); }
h2 { font-size: clamp(1.75rem, 5.4vw, 2.6rem); }
h3 { font-size: 1.35rem; font-weight: 700; line-height: 1.15; }
p { margin: 0 0 16px; }
.mute { color: var(--mute); }
.eyebrow { font-family: var(--f-mono); font-size: 0.78rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent); margin: 0 0 14px; display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.eyebrow::before { content: ""; width: 18px; height: 2px; background: currentColor; display: inline-block; }

/* Header */
.site-head { position: sticky; top: 0; z-index: 20; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); border-bottom: 1px solid var(--edge); }
.site-head .wrap { display: flex; align-items: center; justify-content: space-between; gap: 10px; min-height: 60px; }
.brand { display: inline-flex; align-items: center; padding: 6px 0; flex-shrink: 0; }
.brand img { height: 32px; width: auto; }
.logo-light { display: none !important; }
:root[data-theme="light"] .logo-dark { display: none !important; }
:root[data-theme="light"] .logo-light { display: block !important; }
.nav { display: flex; align-items: center; gap: 2px; }
.nav a { color: var(--text); text-decoration: none; font-weight: 600; font-size: 0.92rem; padding: 0 10px; min-height: 44px; display: inline-flex; align-items: center; border-radius: 10px; }
.nav a:hover, .nav a[aria-current="page"] { color: var(--accent); }
.nav .hide-sm { display: none; }
.theme-btn { width: 44px; height: 44px; border-radius: 12px; border: 1px solid var(--edge-ui); background: transparent; color: var(--text); display: inline-grid; place-items: center; cursor: pointer; margin-left: 4px; }
.theme-btn svg { width: 20px; height: 20px; }
.theme-btn .i-sun { display: none; }
:root[data-theme="light"] .theme-btn .i-sun { display: block; }
:root[data-theme="light"] .theme-btn .i-moon { display: none; }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 48px; padding: 12px 20px; border-radius: var(--r-btn); font-family: var(--f-display); font-weight: 700; font-size: 1.12rem; letter-spacing: 0.02em; text-decoration: none; border: 1px solid transparent; cursor: pointer; transition: transform .15s ease, background .15s ease; }
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-primary:hover { background: color-mix(in srgb, var(--accent) 88%, var(--text)); }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--edge-ui); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn svg { width: 18px; height: 18px; }

/* Sections */
section { padding: 56px 0; }
.sec-head { margin-bottom: 28px; max-width: 720px; }
.sec-head p { color: var(--mute); }
.divider { border: 0; border-top: 1px solid var(--edge); margin: 0; }

/* Hero */
.hero { position: relative; padding: 48px 0 56px; overflow: hidden; }
.hero::before { content: ""; position: absolute; inset: 0; background-image: linear-gradient(var(--grid) 1px, transparent 1px), linear-gradient(90deg, var(--grid) 1px, transparent 1px); background-size: 28px 28px; mask-image: linear-gradient(180deg, #000 30%, transparent 100%); -webkit-mask-image: linear-gradient(180deg, #000 30%, transparent 100%); pointer-events: none; }
.hero .wrap { position: relative; display: grid; gap: 36px; }
.hero h1 { max-width: 14ch; }
.hero h1 em { font-style: normal; color: var(--accent); }
.hero .lede { font-size: 1.1rem; color: var(--mute); max-width: 40ch; }
.hero .lede strong { color: var(--text); font-weight: 600; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.cta-row .btn { flex: 1 1 220px; }

.scope { background: var(--panel); border: 1px solid var(--edge); border-radius: var(--r-card); padding: 14px; box-shadow: var(--shadow); }
.scope-top { display: flex; justify-content: space-between; align-items: center; font-family: var(--f-mono); font-size: 0.72rem; color: var(--mute); letter-spacing: 0.08em; text-transform: uppercase; margin-bottom: 10px; gap: 8px; }
.scope-top .live { color: var(--accent); display: inline-flex; align-items: center; gap: 6px; }
.scope-top .live::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--accent); animation: blink 1.6s steps(2, start) infinite; }
.scope-screen { border-radius: 10px; background: var(--bg); border: 1px solid var(--edge); background-image: linear-gradient(var(--grid) 1px, transparent 1px), linear-gradient(90deg, var(--grid) 1px, transparent 1px); background-size: 10% 20%; position: relative; aspect-ratio: 16 / 8; overflow: hidden; }
.scope-screen svg { width: 100%; height: 100%; }
.trace { fill: none; stroke: var(--accent); stroke-width: 2.5; stroke-linecap: round; stroke-dasharray: 1400; stroke-dashoffset: 1400; animation: draw 2.4s ease-out .3s forwards; }
.trace-2 { fill: none; stroke: var(--spark); stroke-width: 2; stroke-dasharray: 6 6; opacity: .9; }
.scope-read { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin-top: 10px; }
.scope-read div { background: var(--bg); border: 1px solid var(--edge); border-radius: 10px; padding: 8px 10px; }
.scope-read span { display: block; font-family: var(--f-mono); font-size: 0.68rem; color: var(--mute); text-transform: uppercase; letter-spacing: 0.08em; }
.scope-read strong { font-family: var(--f-display); font-size: 1.5rem; line-height: 1.1; }
.scope-read .warn strong { color: var(--spark); }
@keyframes draw { to { stroke-dashoffset: 0; } }
@keyframes blink { to { opacity: 0.2; } }

/* Cards / grids (always even counts) */
.grid { display: grid; gap: 14px; grid-template-columns: 1fr; }
.card { background: var(--panel); border: 1px solid var(--edge); border-radius: var(--r-card); padding: 20px; position: relative; }
.card h3 { margin-bottom: 8px; }
.card p { color: var(--mute); margin-bottom: 12px; font-size: 0.98rem; }
.card .formula { font-family: var(--f-mono); font-size: 0.84rem; color: var(--text); background: var(--bg); border: 1px solid var(--edge); border-radius: 8px; padding: 8px 10px; margin-bottom: 12px; overflow-wrap: anywhere; }
.card .tag { font-family: var(--f-mono); font-size: 0.7rem; color: var(--accent); letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 10px; display: block; }
.tnum, .big-nums strong, .given strong, .scope-read strong, td, .price, .feat { font-variant-numeric: tabular-nums; }
.card a.more svg, .btn svg { width: 18px; height: 18px; flex-shrink: 0; }
.card a.more { gap: 6px; font-weight: 600; font-size: 0.95rem; text-decoration: none; display: inline-flex; align-items: center; min-height: 44px; }
.card a.more:hover { text-decoration: underline; }
.card-link { text-decoration: none; color: inherit; display: block; transition: border-color .15s ease, transform .15s ease; }
.card-link:hover { border-color: var(--accent); transform: translateY(-2px); }
.card-link h3 { color: var(--text); }
.meta { font-family: var(--f-mono); font-size: 0.74rem; color: var(--mute); letter-spacing: 0.04em; margin-bottom: 8px; display: block; }

/* Worked problem preview */
.worksheet { background: var(--panel); border: 1px solid var(--edge); border-radius: var(--r-card); overflow: hidden; box-shadow: var(--shadow); }
.ws-head { display: flex; justify-content: space-between; align-items: center; gap: 10px; padding: 14px 18px; border-bottom: 1px solid var(--edge); flex-wrap: wrap; }
.ws-head .title { font-family: var(--f-display); font-weight: 700; font-size: 1.15rem; }
.pts { font-family: var(--f-mono); font-size: 0.78rem; font-weight: 700; color: var(--spark); border: 1px solid currentColor; border-radius: 999px; padding: 4px 10px; white-space: nowrap; }
.ws-body { padding: 18px; display: grid; gap: 18px; }
.given { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.given div { background: var(--bg); border: 1px solid var(--edge); border-radius: 10px; padding: 8px 10px; }
.given span { display: block; font-size: 0.72rem; color: var(--mute); font-family: var(--f-mono); text-transform: uppercase; letter-spacing: 0.06em; }
.given strong { font-size: 1.02rem; }
.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; counter-reset: s; }
.steps li { counter-increment: s; display: grid; grid-template-columns: 34px 1fr; gap: 12px; align-items: start; }
.steps li::before { content: counter(s); width: 34px; height: 34px; border-radius: 10px; border: 1px solid var(--edge-ui); display: grid; place-items: center; font-family: var(--f-display); font-weight: 800; color: var(--accent); }
.steps .what { font-weight: 600; margin-bottom: 4px; }
.steps code, .mono { font-family: var(--f-mono); font-size: 0.86rem; }
.steps code { display: block; background: var(--bg); border: 1px solid var(--edge); border-radius: 8px; padding: 8px 10px; white-space: pre-wrap; overflow-wrap: anywhere; color: var(--text); }
.answer { display: flex; gap: 12px; align-items: flex-start; border: 1px solid var(--accent); border-radius: 12px; padding: 12px 14px; }
.answer svg { width: 22px; height: 22px; flex-shrink: 0; color: var(--accent); margin-top: 2px; }
.answer p { margin: 0; }
.answer strong { color: var(--text); }
.js .reveal .steps li, .js .reveal .answer { opacity: 0; transform: translateY(8px); }
.js .reveal.on .steps li, .js .reveal.on .answer { animation: rise .5s ease forwards; }
.js .reveal.on .steps li:nth-child(1) { animation-delay: .1s; }
.js .reveal.on .steps li:nth-child(2) { animation-delay: .7s; }
.js .reveal.on .steps li:nth-child(3) { animation-delay: 1.3s; }
.js .reveal.on .steps li:nth-child(4) { animation-delay: 1.9s; }
.js .reveal.on .answer { animation-delay: 2.5s; }
@keyframes rise { to { opacity: 1; transform: none; } }

/* Split blocks */
.split { display: grid; gap: 24px; align-items: start; }
.formula-card { background: var(--panel); border: 1px solid var(--edge); border-radius: var(--r-card); padding: 20px; font-family: var(--f-mono); font-size: 0.9rem; }
.formula-card .row { display: flex; justify-content: space-between; gap: 12px; padding: 10px 0; border-bottom: 1px dashed var(--edge); flex-wrap: wrap; }
.formula-card .row:last-child { border-bottom: 0; }
.formula-card .row span:first-child { color: var(--mute); }
.formula-card .row span:last-child { overflow-wrap: anywhere; }

/* Forms */
.signup { background: var(--panel); border: 1px solid var(--edge); border-radius: var(--r-card); padding: 22px; position: relative; overflow: hidden; }
.signup::after { content: ""; position: absolute; right: -40px; top: -40px; width: 160px; height: 160px; border: 14px solid var(--accent); border-radius: 50%; opacity: 0.08; pointer-events: none; }
.signup h2, .signup h3 { max-width: 20ch; }
.field-row { display: flex; flex-direction: column; gap: 10px; margin-top: 14px; }
label.lbl { font-weight: 600; font-size: 0.92rem; display: block; margin-bottom: 6px; }
input[type="email"], input[type="number"], select {
  width: 100%; min-height: 48px; border-radius: var(--r-input); border: 1px solid var(--edge-ui);
  background: var(--bg); color: var(--text); font: inherit; font-size: 1rem; padding: 10px 12px;
}
select { appearance: none; -webkit-appearance: none; background-image: linear-gradient(45deg, transparent 50%, var(--mute) 50%), linear-gradient(135deg, var(--mute) 50%, transparent 50%); background-position: calc(100% - 20px) 21px, calc(100% - 14px) 21px; background-size: 6px 6px; background-repeat: no-repeat; padding-right: 36px; }
input:focus, select:focus { outline: 3px solid var(--accent); outline-offset: 1px; border-color: var(--accent); }
.hp { position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden; }
.form-note { font-size: 0.85rem; color: var(--mute); margin: 10px 0 0; }
.status { margin-top: 12px; font-weight: 600; display: none; gap: 8px; align-items: center; }
.status.show { display: flex; }
.status svg { width: 20px; height: 20px; flex-shrink: 0; }
.status.ok { color: var(--accent); }
.status.bad { color: var(--err); }

/* Product */
.product { border: 1px solid var(--edge-ui); border-radius: var(--r-card); padding: 24px; background: linear-gradient(160deg, var(--panel) 0%, var(--bg) 100%); }
.badge { display: inline-block; font-family: var(--f-mono); font-size: 0.72rem; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent); border: 1px solid var(--accent); border-radius: 999px; padding: 5px 12px; margin-bottom: 14px; }
.price { font-family: var(--f-display); font-weight: 800; font-size: 3rem; line-height: 1; margin: 8px 0 4px; }
.price small { font-size: 1rem; font-weight: 700; color: var(--mute); font-family: var(--f-body); }
.feat { list-style: none; padding: 0; margin: 20px 0; display: grid; gap: 12px; grid-template-columns: 1fr; }
.feat li { display: flex; gap: 10px; align-items: flex-start; background: var(--bg); border: 1px solid var(--edge); border-radius: 12px; padding: 12px; font-size: 0.97rem; }
.feat svg { width: 20px; height: 20px; color: var(--accent); flex-shrink: 0; margin-top: 2px; }

/* Calculator */
.calc-app { display: grid; gap: 18px; }
.calc-form { background: var(--panel); border: 1px solid var(--edge); border-radius: var(--r-card); padding: 18px; display: grid; gap: 14px; }
.calc-form .two { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.seg { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; padding: 4px; border: 1px solid var(--edge-ui); border-radius: 12px; background: var(--bg); }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg label { min-height: 44px; display: grid; place-items: center; border-radius: 9px; font-weight: 600; font-size: 0.95rem; cursor: pointer; text-align: center; padding: 4px 6px; line-height: 1.2; }
.seg input:checked + label { background: var(--accent); color: var(--accent-ink); }
.seg input:focus-visible + label { outline: 3px solid var(--accent); outline-offset: 2px; }
fieldset { border: 0; padding: 0; margin: 0; min-width: 0; }
legend { font-weight: 600; font-size: 0.92rem; margin-bottom: 6px; padding: 0; }
.unit { font-size: 0.8rem; color: var(--mute); font-weight: 500; }
.result { background: var(--panel); border: 1px solid var(--edge); border-radius: var(--r-card); padding: 18px; }
.big-nums { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-bottom: 14px; }
.big-nums div { background: var(--bg); border: 1px solid var(--edge); border-radius: 12px; padding: 12px; }
.big-nums span { display: block; font-family: var(--f-mono); font-size: 0.7rem; color: var(--mute); text-transform: uppercase; letter-spacing: 0.08em; }
.big-nums strong { font-family: var(--f-display); font-size: 2rem; line-height: 1.1; }
.verdict { display: flex; gap: 10px; align-items: flex-start; border-radius: 12px; padding: 12px 14px; border: 1px solid var(--edge-ui); margin-bottom: 14px; font-weight: 600; }
.verdict svg { width: 22px; height: 22px; flex-shrink: 0; margin-top: 1px; }
.verdict.ok { border-color: var(--accent); color: var(--accent); }
.verdict.over { border-color: var(--spark); color: var(--spark); }
.verdict.bad { border-color: var(--err); color: var(--err); }
.verdict p { margin: 0; color: var(--text); font-weight: 500; }
.verdict .head { display: block; margin-bottom: 2px; }
.calc-steps { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; counter-reset: s; }
.calc-steps li { counter-increment: s; border-left: 2px solid var(--edge-ui); padding: 2px 0 2px 12px; }
.calc-steps li .what { font-weight: 600; font-size: 0.95rem; display: block; margin-bottom: 4px; }
.calc-steps li .what::before { content: "Step " counter(s) ": "; color: var(--accent); font-family: var(--f-mono); font-size: 0.82rem; }
.calc-steps code { font-family: var(--f-mono); font-size: 0.86rem; display: block; white-space: pre-wrap; overflow-wrap: anywhere; }

/* Article */
.article-head { padding: 36px 0 8px; }
.article-head h1 { font-size: clamp(2rem, 7vw, 3.2rem); max-width: 20ch; }
.crumbs { font-size: 0.88rem; color: var(--mute); margin-bottom: 16px; }
.crumbs a { color: var(--mute); }
.prose { padding-bottom: 24px; }
.prose h2 { font-size: clamp(1.5rem, 4.6vw, 2rem); margin-top: 40px; }
.prose h3 { margin-top: 28px; }
.prose ul, .prose ol { padding-left: 22px; margin: 0 0 16px; }
.prose li { margin-bottom: 6px; }
.prose .calc { font-family: var(--f-mono); font-size: 0.88rem; background: var(--panel); border: 1px solid var(--edge); border-left: 3px solid var(--accent); border-radius: 10px; padding: 12px 14px; white-space: pre-wrap; overflow-wrap: anywhere; margin: 0 0 18px; line-height: 1.7; }
.prose .note { background: var(--panel-2); border: 1px solid var(--edge); border-radius: 12px; padding: 14px 16px; margin: 0 0 18px; font-size: 0.97rem; }
.prose .note strong:first-child { color: var(--accent); }
.table-wrap { width: 100%; overflow-x: auto; margin: 0 0 18px; border: 1px solid var(--edge); border-radius: 12px; -webkit-overflow-scrolling: touch; }
table { border-collapse: collapse; width: 100%; font-size: 0.92rem; min-width: 420px; }
th, td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--edge); vertical-align: top; }
th { font-family: var(--f-mono); font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--mute); background: var(--panel); }
tr:last-child td { border-bottom: 0; }
.faq { margin-top: 32px; }
.faq details { border: 1px solid var(--edge); border-radius: 12px; background: var(--panel); margin-bottom: 10px; }
.faq summary { cursor: pointer; padding: 14px 16px; font-weight: 600; min-height: 44px; list-style: none; display: flex; justify-content: space-between; gap: 12px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-family: var(--f-mono); color: var(--accent); font-weight: 700; }
.faq details[open] summary::after { content: "-"; }
.faq details p { padding: 0 16px 14px; margin: 0; color: var(--mute); }
.article-cta { display: grid; gap: 14px; margin: 36px 0 8px; align-items: start; }
.article-cta .field-row { flex-direction: column; }
.article-cta .field-row .btn { width: 100%; }
.related { padding-top: 8px; }

/* Plain pages */
.page { padding-top: 40px; padding-bottom: 56px; }
.page h1 { font-size: clamp(2rem, 7vw, 3rem); }
.page h2 { font-size: 1.6rem; margin-top: 32px; }

/* Footer */
.site-foot { border-top: 1px solid var(--edge); padding: 36px 0 48px; margin-top: 24px; font-size: 0.92rem; }
.foot-grid { display: grid; gap: 22px; grid-template-columns: 1fr 1fr; }
.foot-grid h4 { font-family: var(--f-mono); font-size: 0.74rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--mute); margin: 0 0 8px; font-weight: 700; }
.foot-grid ul { list-style: none; margin: 0; padding: 0; }
.foot-grid li a { color: var(--text); text-decoration: none; min-height: 36px; display: inline-flex; align-items: center; }
.foot-grid li a:hover { color: var(--accent); }
.disclaimer { color: var(--mute); font-size: 0.84rem; margin-top: 28px; padding-top: 20px; border-top: 1px solid var(--edge); max-width: 80ch; }
.foot-logo img { height: 32px; width: auto; margin-bottom: 10px; }

@media (min-width: 560px) {
  .grid.g2, .grid.g4, .grid.g6 { grid-template-columns: 1fr 1fr; }
  .feat { grid-template-columns: 1fr 1fr; }
  .field-row { flex-direction: row; }
  .field-row input { flex: 1; }
  .field-row .btn { flex: 0 0 auto; }
  .nav .hide-sm { display: inline-flex; }
}
@media (min-width: 900px) {
  body { font-size: 18px; }
  section { padding: 80px 0; }
  .brand img { height: 36px; }
  .hero { padding: 72px 0 88px; }
  .hero .wrap { grid-template-columns: 1.1fr 0.9fr; align-items: center; gap: 48px; }
  .grid.g4 { grid-template-columns: repeat(4, 1fr); }
  .split { grid-template-columns: 1fr 1fr; gap: 48px; }
  .cta-row .btn { flex: 0 1 auto; }
  .calc-app { grid-template-columns: 0.9fr 1.1fr; align-items: start; }
  .foot-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; }
  .article-cta { grid-template-columns: 1fr 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-delay: 0ms !important; transition: none !important; scroll-behavior: auto !important; }
  .trace { stroke-dashoffset: 0; }
  .js .reveal .steps li, .js .reveal .answer { opacity: 1; transform: none; }
}