:root { --ink:#12212e; --muted:#5b6b7a; --line:#dbe3ea; --accent:#0b6b5e; --warn-bg:#fff6e5; }
* { box-sizing: border-box }
body { font: 17px/1.65 -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; color: var(--ink); margin: 0; background: #fff }
main { max-width: 760px; margin: 0 auto; padding: 24px 20px 64px }
.site-header { display: flex; flex-wrap: wrap; gap: 16px; align-items: baseline; justify-content: space-between; border-bottom: 1px solid var(--line); padding: 16px 20px; max-width: 1000px; margin: 0 auto }
.site-header nav { display: flex; flex-wrap: wrap; gap: 14px; font-size: 15px }
.brand { font-weight: 700; color: var(--accent); text-decoration: none; font-size: 18px }
a { color: var(--accent) }
h1 { font-size: 31px; line-height: 1.25; margin: 18px 0 6px }
h2 { font-size: 21px; margin: 34px 0 8px }
h3 { font-size: 17px; margin: 22px 0 4px }
.lede { font-size: 19px; color: var(--muted) }
.tool-form { border: 1px solid var(--line); border-radius: 10px; padding: 18px; margin: 24px 0; background: #fbfdfe }
.tool-form p { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 0 0 12px }
.tool-form label { flex: 1 1 210px; font-weight: 600 }
.tool-form .unit { color: var(--muted); font-weight: 400; font-size: 14px }
input, select { flex: 0 0 140px; padding: 9px 11px; border: 1px solid var(--line); border-radius: 6px; font: inherit }
button { background: var(--accent); color: #fff; border: 0; border-radius: 6px; padding: 12px 22px; font: inherit; font-weight: 600; cursor: pointer }
.output { border-radius: 10px; background: #eef7f5; padding: 4px 16px; min-height: 56px }
.output .placeholder { color: var(--muted) }
.output .error { color: #a1291f }
.output table { width: 100%; border-collapse: collapse; margin: 10px 0 }
.output th, .output td { text-align: left; padding: 7px 8px; border-bottom: 1px solid #d7e6e3; font-weight: 500 }
.result { white-space: pre-wrap; font: 14px/1.55 ui-monospace, Menlo, Consolas, monospace }
.examples { width: 100%; border-collapse: collapse; font-size: 15px }
.examples th, .examples td { border-bottom: 1px solid var(--line); padding: 8px; text-align: left; vertical-align: top }
.examples th[scope="row"] { font-weight: 600; width: 42% }
.formula { display: block; background: #f5f7f9; border-left: 3px solid var(--accent); padding: 12px; overflow-x: auto; font-size: 15px }
.cite, .site-footer, .unit-note { color: var(--muted); font-size: 14px }
.disclaimer { background: var(--warn-bg); border-radius: 8px; padding: 14px 16px; font-size: 15px; margin: 32px 0 }
.site-footer { border-top: 1px solid var(--line); margin-top: 48px; padding: 20px; text-align: center }