:root{
  --ink:#0f1a14;--ink-2:#3b4a42;--ink-3:#6b7a72;
  --bg:#f6f7f3;--card:#ffffff;--line:#e3e7e0;
  --brand:#0e9f6e;--brand-d:#0a7a54;--brand-l:#e3f6ee;
  --amber:#f5b52e;--amber-l:#fff4da;--red:#d9534f;
  --radius:18px;--shadow:0 1px 2px rgba(15,26,20,.04),0 8px 24px rgba(15,26,20,.06);
  --max:1120px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:"Inter",system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:var(--ink);background:var(--bg);line-height:1.6;font-size:16px;-webkit-font-smoothing:antialiased}
h1,h2,h3{font-family:"Plus Jakarta Sans","Inter",sans-serif;line-height:1.2;letter-spacing:-.02em;margin:0 0 .5em}
h1{font-size:clamp(2rem,4.5vw,3.1rem);font-weight:800}
h2{font-size:clamp(1.45rem,2.6vw,1.9rem);font-weight:800;margin-top:1.6em}
h3{font-size:1.15rem;font-weight:700;margin-top:1.4em}
p{margin:0 0 1em}
a{color:var(--brand-d)}
.wrap{max-width:var(--max);margin:0 auto;padding:0 20px}

/* header */
.site-header{position:sticky;top:0;z-index:20;background:rgba(246,247,243,.88);backdrop-filter:saturate(1.4) blur(10px);border-bottom:1px solid var(--line)}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;height:64px}
.logo{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);font-family:"Plus Jakarta Sans",sans-serif;font-weight:800;font-size:1.3rem;letter-spacing:-.03em}
.logo b{color:var(--brand)}
.logo svg{width:32px;height:32px}
.nav{display:flex;gap:6px;align-items:center}
.nav a{color:var(--ink-2);text-decoration:none;font-weight:600;font-size:.95rem;padding:8px 12px;border-radius:10px}
.nav a:hover{background:#fff;color:var(--ink)}
.nav .cta{background:var(--ink);color:#fff}
.nav .cta:hover{background:var(--brand-d);color:#fff}
@media(max-width:720px){.nav a:not(.cta){display:none}}

/* hero */
.hero{padding:72px 0 40px;text-align:center;position:relative;overflow:hidden}
.hero:before{content:"";position:absolute;inset:-40% -10% auto;height:520px;background:radial-gradient(closest-side,rgba(14,159,110,.16),transparent),radial-gradient(closest-side at 70% 40%,rgba(245,181,46,.16),transparent);z-index:-1}
.eyebrow{display:inline-flex;align-items:center;gap:8px;background:#fff;border:1px solid var(--line);padding:6px 14px;border-radius:999px;font-size:.85rem;font-weight:600;color:var(--ink-2);margin-bottom:22px}
.eyebrow i{width:8px;height:8px;border-radius:50%;background:var(--brand);display:inline-block}
.hero h1 span{background:linear-gradient(90deg,var(--brand),#13b886 60%,var(--amber));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p.lead{font-size:1.18rem;color:var(--ink-2);max-width:640px;margin:0 auto 28px}
.hero-stats{display:flex;justify-content:center;gap:28px;flex-wrap:wrap;color:var(--ink-3);font-size:.92rem;font-weight:600}
.hero-stats strong{color:var(--ink)}

/* tool grid */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(310px,1fr));gap:18px;margin:36px 0 64px}
.tool-card{display:flex;flex-direction:column;gap:10px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px;text-decoration:none;color:var(--ink);box-shadow:var(--shadow);transition:transform .15s,border-color .15s,box-shadow .15s}
.tool-card:hover{transform:translateY(-3px);border-color:var(--brand);box-shadow:0 14px 34px rgba(14,159,110,.14)}
.tool-card .ic{width:46px;height:46px;border-radius:14px;display:grid;place-items:center;font-size:1.4rem;background:var(--brand-l)}
.tool-card h3{margin:6px 0 0}
.tool-card p{color:var(--ink-2);margin:0;font-size:.97rem}
.tool-card .go{margin-top:auto;font-weight:700;color:var(--brand-d);font-size:.92rem}
.tag{display:inline-block;font-size:.72rem;font-weight:700;padding:3px 9px;border-radius:999px;background:var(--amber-l);color:#8a5a00;text-transform:uppercase;letter-spacing:.04em}

/* sections */
.section{padding:48px 0}
.features{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:18px}
.feature{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:22px}
.feature h3{margin-top:0}
.feature p{color:var(--ink-2);margin:0}

/* calculator page */
.crumbs{font-size:.88rem;color:var(--ink-3);padding-top:24px}
.crumbs a{color:var(--ink-3);text-decoration:none}
.page-head{padding:14px 0 24px}
.page-head p{font-size:1.1rem;color:var(--ink-2);max-width:760px}
.updated{font-size:.85rem;color:var(--ink-3);font-weight:600}
.calc{display:grid;grid-template-columns:1.05fr .95fr;gap:20px;align-items:start}
@media(max-width:880px){.calc{grid-template-columns:1fr}}
.panel{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow)}
.panel h2{margin:0 0 18px;font-size:1.2rem}
.field{margin-bottom:18px}
.field label{display:flex;justify-content:space-between;font-weight:700;font-size:.93rem;margin-bottom:7px}
.field label small{font-weight:500;color:var(--ink-3)}
.input{position:relative}
.input input,.input select{width:100%;font:inherit;font-size:1.05rem;font-weight:600;padding:13px 14px;border:1.5px solid var(--line);border-radius:12px;background:#fbfcfa;color:var(--ink);outline:none;transition:border-color .15s,box-shadow .15s;-moz-appearance:textfield}
.input input::-webkit-outer-spin-button,.input input::-webkit-inner-spin-button{-webkit-appearance:none;margin:0}
.input input:focus,.input select:focus{border-color:var(--brand);box-shadow:0 0 0 4px rgba(14,159,110,.14);background:#fff}
.input.pre input{padding-left:32px}.input.post input{padding-right:44px}
.input .pre,.input .post{position:absolute;top:50%;transform:translateY(-50%);color:var(--ink-3);font-weight:700;pointer-events:none}
.input .pre{left:14px}.input .post{right:14px}
.row2{display:grid;grid-template-columns:1fr 1fr;gap:14px}
@media(max-width:520px){.row2{grid-template-columns:1fr}}
input[type=range]{width:100%;accent-color:var(--brand)}
.seg{display:flex;background:#eef1ec;border-radius:12px;padding:4px;gap:4px}
.seg button{flex:1;border:0;background:transparent;font:inherit;font-weight:700;font-size:.92rem;padding:9px;border-radius:9px;color:var(--ink-2);cursor:pointer}
.seg button.on{background:#fff;color:var(--ink);box-shadow:0 1px 3px rgba(0,0,0,.1)}
.check{display:flex;gap:10px;align-items:flex-start;font-size:.93rem;color:var(--ink-2)}
.check input{accent-color:var(--brand);width:18px;height:18px;margin-top:3px}
.hint{font-size:.84rem;color:var(--ink-3);margin-top:6px}

.result{position:sticky;top:84px;background:var(--ink);color:#fff;border-color:var(--ink)}
.result h2{color:#b9c9c0;font-size:.9rem;text-transform:uppercase;letter-spacing:.08em}
.big{font-family:"Plus Jakarta Sans",sans-serif;font-size:clamp(2.4rem,6vw,3.4rem);font-weight:800;letter-spacing:-.03em;line-height:1;color:#fff;margin:4px 0 6px}
.big-sub{color:#b9c9c0;font-size:.95rem;margin-bottom:20px}
.bar{display:flex;height:12px;border-radius:99px;overflow:hidden;background:#24332b;margin:6px 0 18px}
.bar span{display:block;height:100%;transition:width .35s}
.lines{list-style:none;padding:0;margin:0}
.lines li{display:flex;justify-content:space-between;gap:12px;padding:11px 0;border-top:1px solid #26362d;font-size:.96rem}
.lines li span:first-child{color:#c9d6cf;display:flex;align-items:center;gap:8px}
.lines li b{font-variant-numeric:tabular-nums}
.dot{width:10px;height:10px;border-radius:3px;display:inline-block}
.lines li.total{border-top:1.5px solid #4a5d52;font-size:1.05rem}
.lines li.total span:first-child{color:#fff;font-weight:700}
.note{margin-top:16px;font-size:.82rem;color:#9fb2a8}

/* ad slots: hidden until AdSense is live */
.ad-slot{display:none;margin:28px auto;text-align:center;min-height:100px}
.ads-on .ad-slot{display:block}

/* article */
.article{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:40px;margin:48px 0 24px}
@media(max-width:960px){.article{grid-template-columns:1fr}}
.prose{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:clamp(22px,4vw,44px);font-size:1.03rem}
.prose h2:first-child{margin-top:0}
.prose ul,.prose ol{padding-left:1.3em}.prose li{margin-bottom:.4em}
.prose table{width:100%;border-collapse:collapse;margin:1em 0 1.4em;font-size:.95rem}
.prose th,.prose td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--line)}
.prose th{background:#f3f6f1;font-weight:700}
.callout{background:var(--brand-l);border-left:4px solid var(--brand);padding:14px 18px;border-radius:10px;margin:1.2em 0}
.formula{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;background:#f3f6f1;padding:12px 16px;border-radius:10px;font-size:.92rem;overflow-x:auto}
.faq details{border-bottom:1px solid var(--line);padding:14px 0}
.faq summary{font-weight:700;cursor:pointer;list-style:none;display:flex;justify-content:space-between;gap:16px}
.faq summary:after{content:"+";color:var(--brand);font-size:1.3rem;line-height:1}
.faq details[open] summary:after{content:"–"}
.faq details p{margin:10px 0 0;color:var(--ink-2)}
.side .box{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:20px;margin-bottom:18px;position:sticky;top:84px}
.side h3{margin-top:0;font-size:1rem}
.side a.rel{display:flex;gap:10px;align-items:center;padding:10px 0;border-top:1px solid var(--line);text-decoration:none;color:var(--ink);font-weight:600;font-size:.94rem}
.side a.rel:hover{color:var(--brand-d)}
.sources{font-size:.88rem;color:var(--ink-3)}
.disclaimer{font-size:.86rem;color:var(--ink-3);background:#fff;border:1px dashed var(--line);border-radius:12px;padding:14px 16px;margin:20px 0}

/* simple page */
.simple{max-width:780px;margin:40px auto 60px}

/* footer */
.site-footer{background:var(--ink);color:#b9c9c0;padding:48px 0 30px;margin-top:40px;font-size:.93rem}
.site-footer .cols{display:grid;grid-template-columns:2fr 1fr 1fr;gap:30px}
@media(max-width:720px){.site-footer .cols{grid-template-columns:1fr}}
.site-footer a{color:#dfe9e3;text-decoration:none;display:block;padding:3px 0}
.site-footer a:hover{color:#fff}
.site-footer h4{color:#fff;margin:0 0 10px;font-size:.95rem}
.site-footer .logo{color:#fff;margin-bottom:10px}
.site-footer .bottom{border-top:1px solid #26362d;margin-top:30px;padding-top:18px;font-size:.84rem;color:#8ea398}
.field label.check{justify-content:flex-start;font-weight:600}