:root{--ink:#14213d;--muted:#586174;--bg:#f7f8fb;--card:#fff;--line:#dce1e8;--accent:#1f5eff;--accent2:#eaf0ff;--good:#176b45;--warn:#8a4b08;--max:1120px}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--bg);line-height:1.6}a{color:var(--accent)}.wrap{width:min(var(--max),calc(100% - 32px));margin:auto}.site-header{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}.nav{display:flex;align-items:center;justify-content:space-between;min-height:68px;gap:24px}.brand{font-weight:800;color:var(--ink);text-decoration:none;letter-spacing:-.02em}.nav-links{display:flex;gap:18px;flex-wrap:wrap}.nav-links a{text-decoration:none;color:var(--muted);font-weight:650}.hero{padding:76px 0 42px;background:linear-gradient(180deg,#fff 0%,var(--bg) 100%)}.eyebrow{font-weight:800;color:var(--accent);text-transform:uppercase;letter-spacing:.08em;font-size:.78rem}.hero h1,.page-head h1{font-size:clamp(2.2rem,5vw,4.7rem);line-height:1.03;letter-spacing:-.055em;margin:.35em 0 .25em;max-width:900px}.hero p,.page-head p{font-size:1.18rem;color:var(--muted);max-width:750px}.grid{display:grid;grid-template-columns:repeat(12,1fr);gap:20px}.tool-card,.card{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:24px;box-shadow:0 8px 30px rgba(20,33,61,.04)}.tool-card{grid-column:span 4;text-decoration:none;color:inherit;transition:.18s transform,.18s box-shadow}.tool-card:hover{transform:translateY(-2px);box-shadow:0 12px 35px rgba(20,33,61,.09)}.tool-card h2{margin:.25em 0;font-size:1.25rem}.tool-card p{color:var(--muted);margin-bottom:0}.section{padding:54px 0}.section h2{font-size:2rem;letter-spacing:-.035em}.page-head{padding:52px 0 26px}.calculator-layout{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(300px,.95fr);gap:24px;align-items:start}.field{margin:0 0 18px}.field label{display:block;font-weight:750;margin-bottom:7px}.field small{display:block;color:var(--muted);margin-top:5px}.input-wrap{display:flex;align-items:center;border:1px solid #bac2ce;background:#fff;border-radius:11px;overflow:hidden}.input-wrap span{padding:0 0 0 13px;color:var(--muted);font-weight:700}.input-wrap input,.input-wrap select,input,select{width:100%;font:inherit;border:0;outline:0;padding:12px 13px;background:#fff;color:var(--ink)}select{border:1px solid #bac2ce;border-radius:11px}.check{display:flex;align-items:center;gap:10px;margin:14px 0}.check input{width:auto}.button{appearance:none;border:0;border-radius:11px;background:var(--accent);color:white;font-weight:800;padding:13px 18px;font-size:1rem;cursor:pointer}.result{position:sticky;top:88px}.result .big{font-size:2.45rem;font-weight:850;letter-spacing:-.04em;margin:.1em 0}.result-row{display:flex;justify-content:space-between;gap:20px;padding:10px 0;border-bottom:1px solid var(--line)}.result-row:last-child{border-bottom:0}.result-row span:last-child{font-weight:750;text-align:right}.note{background:var(--accent2);border-radius:12px;padding:14px 16px;color:#2b3a62}.warning{background:#fff6e8;color:var(--warn)}.prose{max-width:820px}.prose h2{margin-top:2em}.prose h3{margin-top:1.6em}.prose p,.prose li{color:#39445a}.source-list li{margin:.5em 0}.footer{border-top:1px solid var(--line);padding:34px 0 50px;color:var(--muted);font-size:.92rem}.breadcrumbs{font-size:.9rem;color:var(--muted);margin-top:18px}.breadcrumbs a{color:var(--muted)}.pill{display:inline-block;background:var(--accent2);color:#244caa;padding:5px 10px;border-radius:999px;font-weight:750;font-size:.82rem}.faq details{border-top:1px solid var(--line);padding:14px 0}.faq summary{cursor:pointer;font-weight:760}.two{grid-column:span 6}.three{grid-column:span 4}.status{font-size:.9rem;color:var(--good);font-weight:750}@media(max-width:820px){.nav{align-items:flex-start;padding:14px 0}.nav-links{justify-content:flex-end}.tool-card,.two,.three{grid-column:span 12}.calculator-layout{grid-template-columns:1fr}.result{position:static}.hero{padding-top:48px}.hero h1,.page-head h1{font-size:2.55rem}}@media(max-width:540px){.nav-links{display:none}.wrap{width:min(100% - 22px,var(--max))}.card,.tool-card{padding:18px}.result .big{font-size:2rem}}
.answer-box{background:#eef4ff;border:1px solid #cbd9ff;border-radius:14px;padding:16px;margin-top:18px}.answer-box strong{display:block;font-size:1.05rem}.mini-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.meta{color:var(--muted);font-size:.9rem}.callout{border-left:4px solid var(--accent);padding:4px 0 4px 16px;margin:24px 0}.footer-links{display:flex;gap:16px;flex-wrap:wrap;margin-top:10px}.footer-links a{color:var(--muted)}@media(max-width:600px){.mini-grid{grid-template-columns:1fr}}

/* Clear blue working surface; readable numbers and compact entry. */
:root{--ink:#132947;--muted:#52657c;--bg:#f1f5f9;--accent:#165dcc;--accent2:#e8f0ff;--line:#d6e0ea;--max:1180px}
body{font-size:16px} .site-header{position:static;border-top:4px solid var(--accent)}
.nav{min-height:80px;flex-wrap:wrap;gap:12px}.brand{font-size:1.2rem}.brand:before{content:'CHN';display:inline-block;padding:6px 8px;margin-right:12px;background:var(--ink);color:white;border-radius:4px;font-size:.9rem;letter-spacing:.03em}
.nav-links{gap:16px}.nav-links a{font-size:.9rem}.nav-links a[aria-current=page]{color:var(--accent);text-decoration:underline;text-underline-offset:8px}
.page-head{padding:26px 0 8px}.page-head h1{font-size:clamp(1.9rem,3.4vw,2.8rem);line-height:1.13;letter-spacing:-.035em;max-width:850px}.page-head p{font-size:1.05rem;margin:12px 0;max-width:850px}.eyebrow{font-size:.8rem}
.section{padding:24px 0}.section h2{font-size:1.6rem}.calculator-layout{grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:28px}.calculator-layout>.card:first-child{display:grid;grid-template-columns:1fr 1fr;gap:0 20px}.calculator-layout>.card:first-child>.mini-grid,.calculator-layout>.card:first-child>h3,.calculator-layout>.card:first-child>.check,.calculator-layout>.card:first-child>.note,.calculator-layout>.card:first-child>.scope,.calculator-layout>.card:first-child>details{grid-column:1/-1}
.card,.tool-card{border-radius:10px;box-shadow:none}.field{margin-bottom:16px}.field label{font-size:.94rem}.field small,small{font-size:.875rem;line-height:1.5}.input-wrap{border-radius:6px}.input-wrap span:last-child{padding-right:12px;white-space:nowrap}.input-wrap input{min-width:0;padding:9px 12px;font-variant-numeric:tabular-nums}select{padding:9px 12px;border-radius:6px}.input-wrap:focus-within,select:focus-visible{outline:3px solid #82aff4;outline-offset:2px}a:focus-visible,summary:focus-visible,input[type=checkbox]:focus-visible{outline:3px solid #165dcc;outline-offset:4px}
.result{background:#132e50;color:#fff;border:0;position:sticky;top:20px;padding:30px}.result .eyebrow{color:#b8d2fb}.result .big{font-size:clamp(2.3rem,4vw,3.6rem);font-variant-numeric:tabular-nums;line-height:1.15;margin:14px 0 20px}.result-row{border-color:#3b5270;font-size:.94rem;padding:12px 0}.result small{display:block;margin-top:18px;color:#d3e1f3}.result .note{background:#fff4d6;color:#603e00;margin-bottom:14px}.result a{color:#c5ddff}.result-unit{color:#c5d5eb;font-size:.95rem;margin-top:-12px;margin-bottom:20px}.check input{accent-color:var(--accent);width:20px;height:20px;flex-shrink:0}.scope{font-size:.9rem;color:var(--muted);margin:0 0 16px}.tool-card{grid-column:span 4;padding:22px}.tool-card h2{font-size:1.15rem}.tool-card:after{content:'Open calculator →';display:block;margin-top:18px;color:var(--accent);font-weight:700}.prose{max-width:900px}.prose h2{margin-top:1.4em}.footer{margin-top:30px}.skip{position:absolute;left:16px;top:-80px;background:white;padding:10px;z-index:30}.skip:focus{top:10px}.related{border-top:1px solid var(--line);margin-top:24px;padding-top:20px}.related nav{display:flex;gap:12px 24px;flex-wrap:wrap}.related a{font-size:.95rem}.validation:empty{display:none}.validation{grid-column:1/-1}.result.invalid .big{font-size:1.8rem}.noscript{padding:16px;background:#fff4d6}table{width:100%;border-collapse:collapse}th,td{text-align:left;padding:12px;border-bottom:1px solid var(--line)}.table-scroll{overflow-x:auto}
@media(max-width:820px){.nav{padding:14px 0}.nav-links{justify-content:flex-start}.calculator-layout{grid-template-columns:1fr}.result{position:static}.tool-card{grid-column:span 6}}
@media(max-width:540px){.nav-links{display:flex;gap:8px 16px}.nav-links a{font-size:.875rem}.calculator-layout>.card:first-child{grid-template-columns:1fr}.card,.result{padding:20px}.tool-card{grid-column:span 12}.page-head{padding-top:20px}.mini-grid{grid-template-columns:1fr}.brand{font-size:1.05rem}.result-row{gap:14px}.wrap{width:calc(100% - 28px)}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.tool-card{transition:none}}

.rebate-fields{grid-column:1/-1;min-width:0;margin:8px 0 20px;padding:16px;border:1px solid var(--line);border-radius:8px}.rebate-fields legend{font-weight:750;padding:0 6px}.rebate-fields small{color:var(--muted)}[hidden]{display:none!important}.result-help{font-size:.875rem;color:#d3e1f3;margin:8px 0 18px;line-height:1.5}.result-heading{font-size:1.05rem;margin:26px 0 8px;color:#c5ddff}.result-summary{margin:0 0 20px;color:#e0ebfa;line-height:1.5}

/* Every calculator stays visible in the opening navigation, including on phones. */
.header-top{display:flex;justify-content:space-between;align-items:center;gap:12px;min-height:66px;padding-top:10px;padding-bottom:10px;flex-wrap:wrap}.header-method{font-size:.875rem;color:var(--muted);text-underline-offset:3px}.tool-menu{background:var(--accent2);border-top:1px solid var(--line);padding:10px 0 14px}.tool-menu p{margin:0 0 8px;font-size:.875rem;font-weight:750;color:var(--ink)}.tool-menu-links{display:flex;flex-wrap:wrap;gap:8px}.tool-menu-links a{display:flex;align-items:center;justify-content:center;min-height:44px;padding:8px 14px;background:#fff;border:1px solid #bfcee3;border-radius:6px;color:var(--ink);font-size:.9375rem;font-weight:650;text-decoration:none;line-height:1.3}.tool-menu-links a:hover{background:#dbe8ff;border-color:var(--accent)}.tool-menu-links a[aria-current=page]{background:var(--accent);color:#fff;border-color:var(--accent);box-shadow:inset 0 -3px 0 rgba(0,0,0,.18)}
@media(max-width:540px){.header-top{gap:6px;min-height:60px}.header-method{font-size:.875rem}.tool-menu{padding:8px 0 12px}.tool-menu-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px}.tool-menu-links a{font-size:.875rem;padding:7px 8px;min-height:44px;text-align:center}.tool-menu p{margin-bottom:6px}}