:root{color-scheme:light;--ink:#153638;--muted:#496064;--accent:#006a68;--line:#cee1df;--wash:#eef8f6}*{box-sizing:border-box}body{margin:0;background:#fff;color:var(--ink);font:17px/1.65 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}header,main,footer{max-width:800px;margin:auto;padding:24px 20px}header{display:flex;flex-wrap:wrap;align-items:center;gap:12px 24px;border-bottom:1px solid var(--line)}header nav{margin-left:auto;font-size:.9rem}.brand{font-weight:850;font-size:1.6rem;text-decoration:none;letter-spacing:-1px;color:var(--ink)}.brand span{color:var(--accent)}.tagline{font-size:.8rem;color:var(--muted)}a{color:var(--accent);text-underline-offset:3px}a:hover{text-decoration-thickness:2px}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #b05c00;outline-offset:3px}h1{font-size:clamp(1.8rem,5vw,2.6rem);line-height:1.18;letter-spacing:-.7px;margin:20px 0 24px}h2{font-size:1.35rem;line-height:1.3;margin-top:36px}h3{font-size:1.05rem;line-height:1.4}.intro{font-size:1.12rem}.eyebrow,.muted,.source,small{font-size:.88rem;color:var(--muted)}.breadcrumbs{display:flex;gap:8px;flex-wrap:wrap;padding:0;list-style:none;font-size:.82rem}.breadcrumbs li+li:before{content:'/';margin-right:8px;color:var(--muted)}.answer{background:var(--wash);border:1px solid #a7d7d0;border-left:5px solid var(--accent);padding:24px;border-radius:10px;margin:24px 0}.answer strong{font-size:1.5rem;line-height:1.3;display:block}.answer p{margin-bottom:0}.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;list-style:none;padding:0}.grid li,.answers li{border:1px solid var(--line);border-radius:8px;padding:16px}.grid a{font-weight:700}.grid p{margin:6px 0 0;font-size:.9rem}.grid small{display:block}.tank-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.table-wrap{overflow-x:auto;margin:20px 0}table{border-collapse:collapse;width:100%;font-size:.9rem}th,td{text-align:left;padding:11px 12px;border-bottom:1px solid var(--line);vertical-align:top}th{background:var(--wash);font-weight:650}td{font-variant-numeric:tabular-nums}.calculator{background:#f7faf9;padding:24px;border:1px solid var(--line);border-radius:10px;margin:32px 0}.calculator h2{margin-top:0}.fields{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}label{display:block;font-size:.88rem;font-weight:600}input,select{display:block;margin:6px 0 0;width:100%;min-height:46px;padding:9px;border:1px solid #829e9b;border-radius:5px;background:white;color:var(--ink);font:inherit}button,.button{display:inline-block;margin-top:18px;background:var(--accent);color:#fff;border:0;border-radius:6px;padding:11px 20px;font:inherit;font-weight:650;cursor:pointer}output{display:block;min-height:110px;margin-top:20px;padding:16px;background:var(--wash);border-radius:6px;font-weight:600;overflow-wrap:anywhere}.answers{list-style:none;padding:0;display:grid;gap:12px}.answers p{margin:4px 0}.answers a{font-weight:700}footer{border-top:1px solid var(--line);font-size:.85rem;margin-top:36px;padding-bottom:36px}.skip{position:absolute;top:-100px;left:12px;background:white;padding:10px;z-index:2}.skip:focus{top:10px}li{margin-bottom:5px}p,li{overflow-wrap:break-word}@media(max-width:520px){.tagline{display:none}header nav{font-size:.8rem}.grid,.fields{grid-template-columns:1fr}.tank-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.calculator{padding:18px}.answer{padding:20px}th,td{padding:9px}body{font-size:16px}}