:root{--blue-600:#1d4ed8;--blue-500:#2563eb;--blue-100:#dbeafe;--blue-50:#eff6ff;--ink:#1e293b;--ink-soft:#475569;--ink-faint:#64748b;--line:#e2e8f0;--bg:#fff;--bg-soft:#f8fafc;--green-600:#15803d;--radius:12px;--maxw:1080px;--shadow:0 1px 3px #0f172a14, 0 4px 12px #0f172a0f}*{box-sizing:border-box}html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}body{color:var(--ink);background:var(--bg);margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;font-size:17px;line-height:1.65}h1,h2,h3{letter-spacing:-.01em;line-height:1.25}h1{margin:0 0 .75rem;font-size:2rem}h2{margin:2.5rem 0 .75rem;font-size:1.45rem}h3{margin:1.75rem 0 .5rem;font-size:1.15rem}p{margin:0 0 1rem}a{color:var(--blue-600)}a:hover{color:var(--blue-500)}.container{max-width:var(--maxw);margin:0 auto;padding:0 1.25rem}main.container{padding-top:2rem;padding-bottom:3rem}.site-header{border-bottom:1px solid var(--line);z-index:50;background:#fff;position:sticky;top:0}.site-header .container{justify-content:space-between;align-items:center;height:64px;display:flex}.brand{color:var(--ink);align-items:center;gap:.6rem;font-size:1.15rem;font-weight:700;text-decoration:none;display:flex}.brand svg{width:30px;height:30px}.nav{gap:1.25rem;display:flex}.nav a{color:var(--ink-soft);font-size:.98rem;font-weight:500;text-decoration:none}.nav a:hover{color:var(--blue-600)}.hero{background:linear-gradient(180deg, var(--blue-50), #fff);border-bottom:1px solid var(--line);text-align:center;padding:3.5rem 0 3rem}.hero h1{margin-bottom:.75rem;font-size:2.4rem}.hero p.lead{color:var(--ink-soft);max-width:640px;margin:0 auto 1.5rem;font-size:1.15rem}.hero .badges{flex-wrap:wrap;justify-content:center;gap:.6rem;display:flex}.badge{border:1px solid var(--line);color:var(--ink-soft);background:#fff;border-radius:999px;padding:.3rem .85rem;font-size:.85rem;display:inline-block}.section-title{margin:2.5rem 0 .25rem;font-size:1.5rem}.section-sub{color:var(--ink-faint);margin-bottom:1.5rem}.cards{grid-template-columns:1fr;gap:1rem;margin-bottom:1rem;display:grid}@media (width>=640px){.cards{grid-template-columns:repeat(2,1fr)}}@media (width>=960px){.cards{grid-template-columns:repeat(3,1fr)}}.tool-card{border:1px solid var(--line);border-radius:var(--radius);color:var(--ink);background:#fff;padding:1.4rem;text-decoration:none;transition:box-shadow .15s,transform .15s;display:block}.tool-card:hover{box-shadow:var(--shadow);transform:translateY(-2px)}.tool-card .icon{font-size:1.8rem}.tool-card h3{margin:.6rem 0 .4rem;font-size:1.08rem}.tool-card p{color:var(--ink-faint);margin:0;font-size:.93rem}.tool-card .go{color:var(--blue-600);margin-top:.7rem;font-size:.93rem;font-weight:600;display:inline-block}.calc{border:1px solid var(--line);border-radius:var(--radius);background:var(--bg-soft);box-shadow:var(--shadow);margin:1.5rem 0;padding:1.5rem}.calc-grid{grid-template-columns:1fr;gap:1rem;display:grid}@media (width>=720px){.calc-grid.two{grid-template-columns:1fr 1fr}}.field label{margin-bottom:.35rem;font-size:.95rem;font-weight:600;display:block}.field .hint{color:var(--ink-faint);font-size:.85rem;font-weight:400}.field input,.field select{border:1px solid var(--line);width:100%;color:var(--ink);background:#fff;border-radius:8px;padding:.65rem .8rem;font-size:1rem}.field input:focus,.field select:focus{outline:2px solid var(--blue-100);border-color:var(--blue-500)}.input-prefix{position:relative}.input-prefix span{color:var(--ink-faint);position:absolute;top:50%;left:.8rem;transform:translateY(-50%)}.input-prefix input{padding-left:1.9rem}.results{border:1px solid var(--line);border-radius:var(--radius);background:#fff;margin-top:1.25rem;padding:1.4rem}.result-hero{text-align:center;border-bottom:1px dashed var(--line);margin-bottom:1rem;padding:.5rem 0 1rem}.result-hero .label{color:var(--ink-faint);font-size:.9rem}.result-hero .value{color:var(--blue-600);font-size:2.2rem;font-weight:800}.result-rows{grid-template-columns:1fr 1fr;gap:.75rem;display:grid}.result-row{background:var(--bg-soft);border-radius:8px;padding:.7rem .9rem}.result-row .k{color:var(--ink-faint);font-size:.82rem}.result-row .v{font-size:1.05rem;font-weight:700}table.data{border-collapse:collapse;width:100%;margin:1rem 0;font-size:.92rem}table.data th,table.data td{text-align:right;border-bottom:1px solid var(--line);padding:.55rem .7rem}table.data th:first-child,table.data td:first-child{text-align:left}table.data thead th{background:var(--bg-soft);font-weight:600}.table-wrap{overflow-x:auto}.versus{grid-template-columns:1fr;gap:1rem;display:grid}@media (width>=720px){.versus{grid-template-columns:1fr 1fr}}.versus .panel{border:1px solid var(--line);border-radius:var(--radius);background:#fff;padding:1.2rem}.versus .panel h3{margin-top:0}.versus .winner{border-color:var(--green-600);box-shadow:0 0 0 1px var(--green-600)}.winner-tag{background:var(--green-600);color:#fff;border-radius:999px;margin-bottom:.5rem;padding:.15rem .7rem;font-size:.78rem;font-weight:700;display:inline-block}.debt-row{border:1px solid var(--line);background:#fff;border-radius:8px;grid-template-columns:1fr 1fr;gap:.6rem;margin-bottom:.6rem;padding:.8rem;display:grid}.debt-row .field label{font-size:.82rem}.btn{border:1px solid var(--blue-500);color:var(--blue-600);cursor:pointer;background:#fff;border-radius:8px;padding:.55rem 1.1rem;font-size:.95rem;font-weight:600;display:inline-block}.btn:hover{background:var(--blue-50)}.btn-primary{background:var(--blue-600);color:#fff;border-color:var(--blue-600)}.btn-primary:hover{background:var(--blue-500)}.prose{max-width:760px}.prose ul,.prose ol{padding-left:1.4rem}.formula{background:var(--bg-soft);border-left:4px solid var(--blue-500);border-radius:0 8px 8px 0;margin:1rem 0;padding:.9rem 1.1rem;font-family:Georgia,Times New Roman,serif;font-size:1.05rem}.example-box{border:1px solid var(--line);border-radius:var(--radius);background:#fff;margin:1rem 0;padding:1.2rem 1.4rem}.example-box h3{margin-top:0}details.faq{border:1px solid var(--line);background:#fff;border-radius:8px;margin-bottom:.6rem}details.faq summary{cursor:pointer;padding:.85rem 1.1rem;font-weight:600;list-style:none}details.faq summary::-webkit-details-marker{display:none}details.faq summary:before{content:"+ ";color:var(--blue-600);font-weight:800}details.faq[open] summary:before{content:"− "}details.faq .a{color:var(--ink-soft);padding:0 1.1rem 1rem}.related{flex-wrap:wrap;gap:.6rem;margin:1rem 0 2rem;display:flex}.related a{border:1px solid var(--line);color:var(--ink-soft);background:#fff;border-radius:999px;padding:.45rem 1rem;font-size:.92rem;text-decoration:none}.related a:hover{border-color:var(--blue-500);color:var(--blue-600)}.updated{color:var(--ink-faint);border-top:1px solid var(--line);margin-top:2.5rem;padding-top:1rem;font-size:.85rem}.notice{border:1px solid var(--blue-100);background:var(--blue-50);border-radius:var(--radius);margin:1.5rem 0;padding:1.1rem 1.3rem}.notice strong{color:var(--blue-600)}.site-footer{border-top:1px solid var(--line);background:var(--bg-soft);color:var(--ink-faint);margin-top:3rem;padding:2.5rem 0 1.5rem;font-size:.92rem}.footer-grid{grid-template-columns:1fr;gap:1.5rem;margin-bottom:1.5rem;display:grid}@media (width>=720px){.footer-grid{grid-template-columns:2fr 1fr 1fr}}.footer-grid h4{color:var(--ink);margin:0 0 .6rem;font-size:1rem}.footer-grid ul{margin:0;padding:0;list-style:none}.footer-grid li{margin-bottom:.4rem}.footer-grid a{color:var(--ink-faint);text-decoration:none}.footer-grid a:hover{color:var(--blue-600)}.copyright{border-top:1px solid var(--line);text-align:center;padding-top:1.2rem}.breadcrumb{color:var(--ink-faint);margin-bottom:1rem;font-size:.85rem}.breadcrumb a{color:var(--ink-faint);text-decoration:none}.breadcrumb a:hover{color:var(--blue-600)}@media (width<=480px){h1{font-size:1.7rem}.hero h1{font-size:1.9rem}.result-hero .value{font-size:1.8rem}.nav{gap:.9rem}}