:root { color-scheme: light; --ink: #22313c; --muted: #53636e; --line: #ccd5db; --surface: #fff; --background: #f1f4f6; --accent: #245c76; --heating: #9b461c; --cooling: #205f9e; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--background); color: var(--ink); font: 1rem/1.55 system-ui, -apple-system, "Segoe UI", sans-serif; }
a { color: var(--accent); text-underline-offset: .18em; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid #126aab; outline-offset: 4px; }
h1, h2, p { margin-top: 0; }
h1 { font-size: clamp(1.7rem, 3vw, 2.4rem); line-height: 1.2; margin-bottom: .8rem; letter-spacing: -.025em; }
h2 { font-size: 1.05rem; margin-bottom: .8rem; }
p { margin-bottom: .8rem; }
.page-width { width: min(1400px, calc(100% - 3rem)); margin-inline: auto; }
.site-header { background: var(--surface); border-bottom: 1px solid var(--line); }
.site-header > div { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding-block: 1rem; }
.brand { font-weight: 750; color: var(--ink); text-decoration: none; font-size: 1.2rem; }
.site-header span, .hint { color: var(--muted); font-size: .875rem; }
.panel { background: var(--surface); border: 1px solid var(--line); border-radius: 5px; padding: 1.25rem; min-width: 0; }
fieldset { border: 0; padding: 0; margin: 1rem 0 0; min-width: 0; }
legend { padding: 0; margin-bottom: .6rem; font-weight: 650; font-size: .85rem; }
label { display: grid; align-content: start; gap: .35rem; font-size: .85rem; }
input, select, button { font: inherit; font-variant-numeric: tabular-nums; min-height: 44px; border: 1px solid #aab8c1; border-radius: 3px; padding: .5rem .65rem; }
input, select { width: 100%; min-width: 0; background: #fff; color: var(--ink); }
input:disabled, select:disabled, button:disabled { opacity: 1; color: #56646d; background: #edf1f3; cursor: not-allowed; }
button { cursor: pointer; color: var(--ink); background: #fff; }
summary { cursor: pointer; padding-block: .5rem; }
details p:first-of-type { margin-top: .8rem; }
footer { display: flex; justify-content: space-between; flex-wrap: wrap; gap: .75rem; padding-block: 1.5rem; color: var(--muted); font-size: .875rem; }
.skip-link { position: absolute; left: 1rem; top: -6rem; background: white; padding: .7rem; z-index: 1; }
.skip-link:focus { top: .5rem; }
.test-results { padding-left: 1.5rem; overflow-wrap: anywhere; }
.test-results li { margin-block: .5rem; }
.pass { color: #24633c; }
.fail { color: #a02121; font-weight: 650; }
@media (max-width: 600px) { .page-width { width: calc(100% - 1.5rem); } .site-header > div { align-items: start; flex-direction: column; gap: .2rem; } .panel { padding: 1rem; } }