:root{color-scheme:light;--ink:#1a242b;--muted:#53616a;--line:#d6dde1;--accent:#075b70;--paper:#fff;--soft:#f4f7f8}
*{box-sizing:border-box}html{scroll-padding-top:80px}body{margin:0;background:var(--paper);color:var(--ink);font:17px/1.85 -apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;overflow-wrap:anywhere}a{color:var(--accent);text-underline-offset:3px}a:focus-visible,summary:focus-visible,input:focus-visible{outline:3px solid #e6a137;outline-offset:4px}header{position:sticky;top:0;z-index:2;background:rgba(255,255,255,.97);border-bottom:1px solid var(--line)}header nav{max-width:850px;margin:auto;display:flex;gap:22px;padding:12px 24px;font-size:14px;align-items:center}header a{text-decoration:none}header .brand{font-weight:750;margin-right:auto;color:var(--ink)}main{max-width:850px;margin:42px auto 70px;padding:0 24px}h1{font-size:clamp(29px,4.6vw,42px);line-height:1.3;letter-spacing:-.025em;margin:30px 0}h2{font-size:25px;line-height:1.5;margin:58px 0 20px;padding-top:20px;border-top:1px solid var(--line)}h3{font-size:20px;line-height:1.5;margin:30px 0 14px}p{margin:0 0 20px}strong{font-weight:720}blockquote{margin:24px 0;padding:16px 22px;background:var(--soft);border-left:3px solid var(--accent)}blockquote p:last-child{margin-bottom:0}li{padding-left:2px;margin-bottom:10px}ul,ol{padding-left:25px}details{margin:24px 0;border:1px solid var(--line);padding:12px 18px;border-radius:4px}summary{cursor:pointer;font-weight:650}details ol{font-size:15px;margin-bottom:6px}.table-wrap{overflow-x:auto;margin:24px 0;border:1px solid var(--line);border-radius:3px}table{width:100%;border-collapse:collapse;font-size:14px;line-height:1.65;margin:0;min-width:580px}th,td{text-align:left;padding:12px 14px;border-bottom:1px solid var(--line);vertical-align:top}th{background:var(--soft);font-weight:650}tr:last-child td{border-bottom:0}.table-wrap col{width:auto!important}footer{max-width:850px;padding:24px;margin:auto;border-top:1px solid var(--line);font-size:13px;color:var(--muted)}.calculator{margin:36px 0;padding:24px;border:1px solid var(--line);background:#f7fafb;border-radius:6px;scroll-margin-top:80px}.calculator h3{margin-top:0}.note{font-size:14px;color:var(--muted);line-height:1.7}.fields{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px 16px}.field{display:flex;flex-direction:column;min-width:0;font-size:14px;font-weight:650}.field small{display:block;font-weight:400;color:var(--muted);font-size:12px;line-height:1.5;margin:5px 0 8px}.field input{width:100%;min-width:0;padding:10px;border:1px solid #99aeb8;border-radius:3px;background:#fff;color:var(--ink);font:inherit;line-height:1.4;font-size:17px;min-height:44px;margin-top:auto}.results{border-top:1px solid var(--line);margin-top:24px;padding-top:16px;display:grid;grid-template-columns:1fr 1fr;gap:14px}.result{font-size:13px;color:var(--muted)}.result output{display:block;font-variant-numeric:tabular-nums;font-size:22px;line-height:1.5;color:var(--ink);font-weight:650}.result output.negative{color:#a12720}.result output.positive{color:#087058}#calc-status{margin:12px 0 0;font-size:13px;color:var(--muted)}.quick{font-size:14px;color:var(--muted)}.lead{font-size:19px;line-height:1.85}.decision-strip{border-left:3px solid var(--accent);padding-left:18px;margin:24px 0 28px}.noscript{padding:12px;background:#fff2dc}
@media(max-width:600px){body{font-size:16px;line-height:1.9}header nav{padding:10px 18px;gap:16px;font-size:13px}main{padding:0 20px;margin-top:28px}h1{font-size:30px}h2{font-size:23px;margin-top:42px}h3{font-size:19px}blockquote{padding:14px 16px}.calculator{padding:18px 14px;margin-left:-6px;margin-right:-6px}.fields{grid-template-columns:repeat(2,minmax(0,1fr));gap:16px 12px}.results{gap:16px 10px}.result output{font-size:20px}table{min-width:560px;font-size:13px}th,td{padding:10px 12px}}
@media(prefers-reduced-motion:no-preference){html{scroll-behavior:smooth}}@media print{header,details,.quick{display:none}main{max-width:none;margin:0;padding:0;font-size:11pt}h1{font-size:23pt}h2{font-size:16pt}h3{font-size:13pt}h2,h3{break-after:avoid}blockquote,.calculator{break-inside:avoid}a{color:inherit}table{min-width:0;font-size:9pt}.table-wrap{overflow:visible}.calculator input{border:0;padding:0}footer{padding:10px 0}}