:root{color-scheme:light;--ink:#212121;--muted:#626873;--line:#e2e4e7;--accent:#46a5dc;--paper:#fff;--tint:#edf7fd}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:17px/1.6 system-ui,-apple-system,"Segoe UI",sans-serif}
a{color:var(--ink);text-decoration-color:var(--accent);text-underline-offset:4px}header{max-width:1240px;margin:auto;padding:25px 32px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line)}
.brand{display:inline-flex;align-items:center;gap:0;direction:ltr;font-size:27px;font-weight:750;letter-spacing:-1px;text-decoration:none;color:var(--ink)}.brand img{width:56px;height:56px;object-fit:contain;margin-inline-start:-12px;margin-inline-end:-5px}.tag{display:none;font-size:12px;text-transform:uppercase;letter-spacing:2px;color:var(--muted)}
main{max-width:1240px;margin:auto;padding:32px}nav{font-size:13px;color:var(--muted);margin-bottom:35px}nav a{color:inherit}h1{font-size:34px;line-height:1.2;letter-spacing:-.7px;max-width:900px;margin:20px 0}h2{font-size:24px;line-height:1.35;margin:0 0 22px}h3{font-size:17px}.intro strong{color:var(--ink);font-weight:650}.intro{max-width:760px;font-size:19px;color:var(--muted);margin-bottom:42px}
.layout{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:32px;align-items:start}.panel{background:#fff;border:1px solid var(--line);border-radius:14px;padding:30px;margin-bottom:24px;box-shadow:0 2px 10px #00000007}.step{background:var(--accent);color:var(--ink);display:inline-grid;place-items:center;border:1px solid var(--line);width:30px;height:30px;border-radius:50%;font-size:13px;margin-inline-end:12px}
label{display:block;font-weight:650;margin-bottom:8px}.field{margin-bottom:24px}input,select{font:inherit;color:var(--ink);background:#fff;border:1px solid #a5adbc;border-radius:9px;padding:12px;width:100%;min-height:50px}input:focus,select:focus,a:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:3px}.unit{font-size:13px;font-weight:400;color:var(--muted)}small,.note{font-size:13px;color:var(--muted)}.note{border-inline-start:3px solid #cedafa;padding-inline-start:14px}
.formula{direction:ltr;unicode-bidi:isolate;overflow-wrap:anywhere;font:24px/1.5 system-ui,-apple-system,"Segoe UI",sans-serif;background:var(--tint);color:var(--ink);font-weight:550;padding:22px;border-radius:10px}.symbol{font-size:14px;color:var(--muted);overflow-wrap:anywhere}
aside{position:sticky;top:24px}aside .panel{background:#fff;text-align:center}.qr{background:#fff;border-radius:12px;padding:12px;margin:24px auto;max-width:268px}.qr svg{display:block;width:100%;height:auto}.button{display:block;background:var(--accent);color:var(--ink);border-radius:10px;padding:15px;text-decoration:none;font-weight:650;margin-top:24px}.button[aria-disabled]{opacity:.5;pointer-events:none}
#error{color:#9d2828;overflow-wrap:anywhere;font-size:14px}.related{padding:12px 0}.related a{display:block;padding:9px 0}footer{border-top:1px solid var(--line);margin:36px auto 0;padding:26px 32px;max-width:1240px;color:var(--muted);font-size:13px}
[hidden]{display:none!important}.preview{font-size:12px;border:1px solid var(--line);border-radius:20px;padding:4px 12px;color:var(--muted)}.catalog{columns:3;column-gap:30px}.catalog a{display:block;break-inside:avoid;padding:8px}
@media(max-width:800px){header,main{padding:20px}.tag{display:none}.layout{grid-template-columns:1fr;gap:0}aside{position:static}.panel{padding:22px}h1{font-size:30px;letter-spacing:-.5px;overflow-wrap:anywhere}.formula{font-size:22px;padding:20px}.catalog{columns:1}.intro{font-size:17px}}

/* Natural-script parameter names inside mathematical notation. */
.formula bdi{font-family:system-ui,-apple-system,"Segoe UI",sans-serif;letter-spacing:normal}

[dir="rtl"] h1,[dir="rtl"] .brand,[dir="rtl"] .tag{letter-spacing:normal}

select{background-color:var(--tint);border-color:var(--accent)}

.handoff-panel{max-width:680px;margin:24px auto}.handoff-panel h1{font-size:30px}.button.secondary{background:#fff;color:var(--ink);border:1px solid var(--line)}

/* Full handoff at both reading entry and exit; a single column on phones. */
.handoff-card{display:grid;grid-template-columns:minmax(0,1fr) 400px;gap:12px 36px;align-items:center}
.handoff-card > *{min-width:0}
.handoff-card h2{margin-bottom:12px}.handoff-card p{margin:12px 0}
.handoff-card .button{max-width:560px;text-align:center;min-height:50px}
.handoff-card .qr{margin:0 auto;width:400px;max-width:100%}
.handoff-card .qr svg{width:calc(var(--qr-modules) * 3px);max-width:100%;margin:auto;shape-rendering:crispEdges}
.handoff-card .handoff-error{grid-column:1/-1;color:#9d2828;overflow-wrap:anywhere}
.handoff-card .handoff-error:empty{display:none}
.calculation-content{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:24px}
.calculation-content .related{grid-column:1/-1;margin-bottom:24px}
@media(max-width:800px){.handoff-card,.calculation-content{grid-template-columns:minmax(0,1fr)}.handoff-card .button{max-width:none}.handoff-card .qr{margin:12px auto}.calculation-content{gap:0}}
@media(max-width:800px){.handoff-card .qr svg{width:calc(var(--qr-modules) * 2px)}}