@font-face { font-family: "Atkinson Hyperlegible"; src: url(/fonts/atkinson-hyperlegible-latin-400-normal.woff2) format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "Atkinson Hyperlegible"; src: url(/fonts/atkinson-hyperlegible-latin-400-italic.woff2) format("woff2"); font-weight: 400; font-style: italic; font-display: swap; }
@font-face { font-family: "Atkinson Hyperlegible"; src: url(/fonts/atkinson-hyperlegible-latin-700-normal.woff2) format("woff2"); font-weight: 700; font-display: swap; }
@font-face { font-family: "IBM Plex Mono"; src: url(/fonts/ibm-plex-mono-latin-400-normal.woff2) format("woff2"); font-weight: 400; font-display: swap; }
:root { --bg: #f1f3f4; --panel: #e6eaec; --ink: #17202a; --muted: #536170; --rule: #cdd4d9; --accent: #0a6c86; --answer: #dcebef; --sans: "Atkinson Hyperlegible", system-ui, sans-serif; --mono: "IBM Plex Mono", ui-monospace, monospace; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 400 17px/1.6 var(--sans); }
a { color: var(--accent); text-underline-offset: 3px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.skip { position: absolute; left: -999px; } .skip:focus { left: 12px; top: 8px; background: var(--ink); color: #fff; padding: 6px 10px; z-index: 5; }
.bar { border-bottom: 1px solid var(--rule); background: var(--bg); }
.bar .in { max-width: 1320px; margin: 0 auto; padding: 12px 20px; display: flex; align-items: center; gap: 20px; flex-wrap: wrap; }
.brand { font-weight: 700; font-size: 18px; color: var(--ink); text-decoration: none; }
.brand span { color: var(--accent); }
.bar nav { display: flex; gap: 18px; font-size: 15px; margin-left: auto; }
.bar nav a { color: var(--muted); text-decoration: none; } .bar nav a:hover { color: var(--ink); }
.shell { max-width: 1320px; margin: 0 auto; padding: 0 20px; display: grid; grid-template-columns: 250px minmax(0, 1fr) 220px; gap: 40px; }
.side { padding: 24px 0; font-size: 15px; position: sticky; top: 0; align-self: start; max-height: 100vh; overflow: auto; }
.side h2 { font-size: 13px; color: var(--muted); margin: 18px 0 6px; font-weight: 700; }
.side ul { list-style: none; padding: 0; margin: 0; }
.side li a { display: block; padding: 5px 8px; color: var(--ink); text-decoration: none; line-height: 1.35; }
.side li a:hover { background: var(--panel); }
.side li a[aria-current="page"] { background: var(--panel); font-weight: 700; }
.toc { padding: 28px 0; font-size: 14px; position: sticky; top: 0; align-self: start; }
.toc h2 { font-size: 13px; color: var(--muted); margin: 0 0 8px; }
.toc ul { list-style: none; padding: 0; margin: 0; } .toc li a { display: block; padding: 3px 0; color: var(--muted); text-decoration: none; } .toc li a:hover { color: var(--ink); }
main { padding: 28px 0 72px; min-width: 0; }
@media (max-width: 1100px) { .shell { grid-template-columns: 220px minmax(0, 1fr); } .toc { display: none; } }
@media (max-width: 760px) { .shell { grid-template-columns: 1fr; gap: 0; } .side { position: static; max-height: none; border-bottom: 1px solid var(--rule); padding: 12px 0; } .side details:not([open]) ul { display: none; } }
h1 { font-size: clamp(28px, 3.6vw, 38px); line-height: 1.15; margin: 0 0 12px; }
h2 { font-size: 24px; line-height: 1.25; margin: 38px 0 10px; }
h3 { font-size: 19px; margin: 26px 0 8px; }
.crumbs { font-size: 14px; color: var(--muted); margin: 0 0 10px; }
.reviewed { font-size: 14px; color: var(--muted); margin: 0 0 20px; }
.short { background: var(--answer); padding: 16px 20px; margin: 0 0 26px; }
.short strong { display: block; font-size: 14px; margin-bottom: 4px; }
.short p { margin: 0; font-size: 19px; }
.content { max-width: 72ch; }
.content table, table.data { border-collapse: collapse; width: 100%; font-size: 16px; margin: 16px 0; }
.content th, .content td, table.data th, table.data td { border-bottom: 1px solid var(--rule); padding: 8px 12px 8px 0; text-align: left; vertical-align: top; }
.content th, table.data th { font-size: 14px; color: var(--muted); }
table.data td.r, table.data th.r { text-align: right; font-family: var(--mono); font-size: 15px; }
.content code, .num { font-family: var(--mono); font-size: 0.92em; }
.content ol li { margin-bottom: 6px; }
.takeaways ul { padding-left: 20px; }
.faq dt { font-weight: 700; margin-top: 14px; } .faq dd { margin: 4px 0 0; }
.sources { font-size: 15px; color: var(--muted); } .sources ol { padding-left: 20px; }
.qlist { list-style: none; padding: 0; margin: 0; }
.qlist li { padding: 14px 0; border-bottom: 1px solid var(--rule); }
.qlist a { font-weight: 700; font-size: 19px; text-decoration: none; color: var(--ink); } .qlist a:hover { color: var(--accent); }
.qlist p { margin: 4px 0 0; color: var(--muted); font-size: 16px; }
.calc { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; max-width: 720px; margin: 10px 0 20px; }
.calc label { display: block; font-size: 14px; font-weight: 700; margin-bottom: 4px; }
.calc input, .calc select { width: 100%; font: 400 17px var(--sans); padding: 9px 10px; border: 1px solid #9aa7b1; background: #fbfcfc; color: var(--ink); }
@media (max-width: 640px) { .calc { grid-template-columns: 1fr; } }
.result { max-width: 720px; }
.result .big { font-size: 26px; font-weight: 700; margin: 4px 0 8px; }
.cal svg { width: 100%; max-width: 520px; height: auto; display: block; }
.cal .axis { stroke: var(--rule); } .cal .diag { stroke: var(--muted); stroke-dasharray: 4 4; } .cal .pt1 { fill: var(--accent); } .cal .pt7 { fill: none; stroke: var(--ink); stroke-width: 1.5; } .cal text { font: 11px var(--mono); fill: var(--muted); }
.legend { font-size: 14px; color: var(--muted); }
footer { border-top: 1px solid var(--rule); margin-top: 24px; padding: 20px 0 40px; font-size: 14px; color: var(--muted); }
footer nav { display: flex; flex-wrap: wrap; gap: 6px 18px; margin-bottom: 6px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }