/* StatCalcHub: light airy design system (Solvely-style refresh).
   Flat pale-blue page wash, white cards with soft wide shadows,
   Poppins display type + Inter body, bright blue primary,
   pill segmented controls. No external requests:
   Poppins and Inter are self-hosted. */

@font-face{
  font-family:"Poppins";
  src:url("/assets/fonts/poppins-600.woff2") format("woff2");
  font-weight:600;
  font-style:normal;
  font-display:swap;
}
@font-face{
  font-family:"Poppins";
  src:url("/assets/fonts/poppins-700.woff2") format("woff2");
  font-weight:700;
  font-style:normal;
  font-display:swap;
}
@font-face{
  font-family:"Poppins";
  src:url("/assets/fonts/poppins-800.woff2") format("woff2");
  font-weight:800;
  font-style:normal;
  font-display:swap;
}
@font-face{
  font-family:"Inter";
  src:url("/assets/fonts/inter-var.woff2") format("woff2");
  font-weight:400 800;
  font-style:normal;
  font-display:swap;
}

:root{
  --bg:#EDF2FD;
  --card:#FFFFFF;
  --soft:#F5F8FE;
  --ink:#111827;
  --ink-soft:#374151;
  --muted:#6B7280;
  --line:#E2E8F2;
  --line-strong:#CBD5E4;
  --primary:#2563EB;
  --primary-hover:#1D4ED8;
  --primary-active:#1E40AF;
  --primary-soft:#EAF1FE;
  --primary-line:#C9DBFC;
  --violet:#8B5CF6;
  --ring:rgba(37,99,235,.18);
  --warn-bg:#FFF7ED;
  --warn-line:#FDE6CE;
  --warn-accent:#D97706;
  --code-bg:#1E293B;
  --code-ink:#E5E7EB;
  --code-label:#93C5FD;
  --shadow-sm:0 1px 2px rgba(16,24,40,.05),0 1px 3px rgba(16,24,40,.06);
  --shadow:0 4px 6px -1px rgba(16,24,40,.08),0 2px 4px -2px rgba(16,24,40,.06);
  --shadow-lg:0 24px 48px -12px rgba(30,64,175,.16),0 8px 20px -8px rgba(16,24,40,.10);
  --r-xl:22px;
  --r-lg:16px;
  --r-md:12px;
  --r-sm:10px;
  --mono:ui-monospace,"SF Mono","Cascadia Mono",Menlo,Consolas,"Liberation Mono",monospace;
  --sans:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --display:"Poppins","Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;background:var(--bg);color:var(--ink);
  font-family:var(--sans);font-size:17px;line-height:1.65;
  -webkit-font-smoothing:antialiased;
  overflow-x:clip;
}
::selection{background:var(--primary-line)}
.wrap{max-width:1320px;margin:0 auto;padding:0 24px}

/* ---------- header ---------- */
header.site{
  position:sticky;top:0;z-index:50;background:#fff;
  border-bottom:1px solid var(--line);
  box-shadow:0 1px 8px rgba(16,24,40,.04);
}
header.site .wrap{display:flex;align-items:center;gap:28px;padding-top:13px;padding-bottom:13px}
.logo{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);
  font-family:var(--display);font-size:22px;font-weight:700;letter-spacing:-.01em}
.logo svg{flex:none;display:block}
.logo svg rect:nth-of-type(1){fill:var(--primary);stroke:none;rx:8px}
.logo svg rect:nth-of-type(2),.logo svg rect:nth-of-type(4){fill:#fff}
.logo svg rect:nth-of-type(3){fill:#C4B5FD}
.logo .dot{color:var(--primary)}
nav.main{display:flex;gap:4px;margin:0 auto;flex-wrap:wrap;justify-content:center}
nav.main a{color:var(--ink-soft);text-decoration:none;font-size:15px;font-weight:500;
  padding:7px 12px;border-radius:8px}
nav.main a:hover{color:var(--primary);background:var(--primary-soft)}
.nav-cta{flex:none;text-decoration:none;color:var(--ink);font-size:15px;font-weight:600;
  border:1.5px solid var(--ink);border-radius:999px;padding:7px 20px;background:#fff;
  transition:background .15s ease,color .15s ease,border-color .15s ease}
.nav-cta:hover{background:var(--ink);color:#fff}

/* ---------- type ---------- */
h1{font-family:var(--display);font-size:40px;line-height:1.15;letter-spacing:-.02em;margin:28px 0 10px;font-weight:700;color:var(--ink)}
h2{font-family:var(--display);font-size:27px;line-height:1.25;margin:40px 0 12px;font-weight:700;letter-spacing:-.015em}
h3{font-size:18px;margin:24px 0 8px;font-weight:700;letter-spacing:-.01em}
p{margin:0 0 14px}
a{color:var(--primary);text-underline-offset:3px}
a:hover{color:var(--primary-hover)}
.lede{font-size:19px;color:var(--ink-soft);max-width:46em;margin-bottom:22px;line-height:1.6}
.crumbs{font-size:13.5px;color:var(--muted);padding-top:18px}
.crumbs a{color:var(--ink-soft);text-decoration:none}
.crumbs a:hover{color:var(--primary);text-decoration:underline}
b,strong{font-weight:700}

/* ---------- homepage hero ---------- */
body.home .crumbs{text-align:center}
body.home h1{
  text-align:center;font-size:62px;font-weight:800;letter-spacing:-.025em;
  line-height:1.08;margin:38px 0 16px;
}
body.home h1 .grad{
  background:linear-gradient(92deg,#2E7CF6 10%,#8B5CF6 90%);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;color:transparent;
}
body.home .lede{
  text-align:center;max-width:640px;margin:0 auto 28px;
  font-size:18.5px;color:#5B6472;
}

/* ---------- quick answer ---------- */
.quick{background:var(--primary-soft);border:1px solid var(--primary-line);
  border-left:4px solid var(--primary);border-radius:var(--r-md);
  box-shadow:var(--shadow-sm);
  padding:15px 18px;margin:22px 0;font-size:16.5px}
.quick b{color:var(--primary-active)}

/* ---------- tool workspace ---------- */
.toolcard{background:var(--card);border:1px solid var(--line);border-radius:var(--r-xl);
  box-shadow:var(--shadow-lg);padding:30px 30px 24px;margin:6px 0 26px}
.toolcard>h2{margin:0 0 4px;font-size:23px;font-weight:700}
.toolcard .sub{color:var(--muted);font-size:15.5px;margin:0 0 18px}
.toolcard label{display:block;font-size:12.5px;font-weight:600;letter-spacing:.05em;
  text-transform:uppercase;color:var(--muted);margin:16px 0 7px}
.toolcard textarea,.toolcard input[type=number],.toolcard input[type=text]{
  width:100%;border:1px solid var(--line-strong);background:var(--card);
  font-family:var(--mono);font-size:16px;padding:12px 14px;color:var(--ink);
  border-radius:var(--r-sm);transition:border-color .15s ease,box-shadow .15s ease}
.toolcard textarea{min-height:88px;resize:vertical;line-height:1.55}
.toolcard textarea::placeholder,.toolcard input::placeholder{color:#9AA3B2}
.toolcard textarea:focus,.toolcard input:focus{outline:none;border-color:var(--primary);
  box-shadow:0 0 0 3px var(--ring)}
.toolcard input[type=checkbox]{accent-color:var(--primary);width:17px;height:17px;vertical-align:-3px}
.pstat{font-family:var(--mono);font-size:13.5px;color:var(--muted);margin-top:7px;min-height:20px;
  font-variant-numeric:tabular-nums}

/* segmented pill radio groups */
.radio-row{display:flex;gap:8px;flex-wrap:wrap;margin:2px 0 6px}
.radio-row label{position:relative;display:inline-flex;align-items:center;
  text-transform:none;letter-spacing:0;font-size:14.5px;font-weight:500;color:var(--ink-soft);
  border:1px solid var(--line-strong);border-radius:999px;background:var(--card);
  padding:8px 16px;margin:0;cursor:pointer;
  transition:background .15s ease,border-color .15s ease,color .15s ease}
.radio-row label:hover{border-color:var(--primary);color:var(--primary)}
.radio-row input{position:absolute;opacity:0;width:1px;height:1px;margin:0;pointer-events:none}
.radio-row label:has(input:checked){background:var(--primary);border-color:var(--primary);
  color:#fff;font-weight:600}
.radio-row label:has(input:checked):hover{background:var(--primary-hover);border-color:var(--primary-hover);color:#fff}
.radio-row label:has(input:focus-visible){box-shadow:0 0 0 3px var(--ring)}

.btnrow{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin-top:18px}
.btn{background:var(--primary);color:#fff;border:1px solid transparent;
  font-family:var(--sans);font-size:16px;font-weight:600;padding:13px 34px;cursor:pointer;
  border-radius:var(--r-md);box-shadow:var(--shadow-sm);
  transition:background .15s ease,box-shadow .15s ease}
.btn:hover{background:var(--primary-hover);box-shadow:var(--shadow)}
.btn:active{background:var(--primary-active)}
.btn:focus-visible{outline:none;box-shadow:0 0 0 3px var(--ring)}
.btn-ghost{background:var(--card);color:var(--ink-soft);border:1px solid var(--line-strong);
  font-size:14px;font-weight:600;padding:9px 18px;cursor:pointer;border-radius:999px;
  font-family:var(--sans);transition:border-color .15s ease,color .15s ease,background .15s ease}
.btn-ghost:hover{border-color:var(--primary);color:var(--primary);background:var(--primary-soft)}
.btn-ghost:focus-visible{outline:none;box-shadow:0 0 0 3px var(--ring)}
.btn-small{padding:6px 14px;font-size:13px}

/* ---------- results ---------- */
.results{display:none;margin-top:22px;border-top:1px solid var(--line);padding-top:20px}
.results.show{display:block}
.rgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:10px;margin-bottom:16px}
.rcell{padding:14px 16px;border:1px solid var(--line);border-radius:var(--r-md);background:var(--soft)}
.rk{font-size:11.5px;font-weight:600;letter-spacing:.05em;text-transform:uppercase;color:var(--muted)}
.rv{font-family:var(--mono);font-size:20px;font-weight:600;margin-top:4px;word-break:break-word;
  font-variant-numeric:tabular-nums}
.rcell.hero{background:var(--primary);border-color:transparent}
.rcell.hero .rk{color:#BFDBFE}
.rcell.hero .rv{color:#fff;font-size:26px}
.chartbox{border:1px solid var(--line);border-radius:14px;background:var(--card);
  box-shadow:var(--shadow-sm);padding:16px 18px 10px;margin:0 0 16px}
.chartbox .ct{font-size:12px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);margin-bottom:4px}
.chartbox svg{width:100%;height:auto;display:block}
.interp{border-left:4px solid var(--primary);background:var(--primary-soft);
  border-radius:var(--r-md);padding:14px 18px;margin:0 0 16px;font-size:16px}
.interp .it{font-family:var(--sans);font-size:12px;font-weight:700;letter-spacing:.06em;
  text-transform:uppercase;color:var(--primary);display:block;margin-bottom:4px}
.aparow{display:flex;gap:10px;align-items:stretch;flex-wrap:wrap;margin:0 0 16px}
.apa{flex:1;min-width:230px;border:1px solid var(--line);border-radius:var(--r-sm);background:var(--soft);
  font-family:var(--mono);font-size:14.5px;padding:11px 14px;display:flex;align-items:center}
.apa .al{font-family:var(--sans);font-size:11px;font-weight:700;letter-spacing:.06em;
  text-transform:uppercase;color:var(--muted);margin-right:10px;white-space:nowrap}
details.steps-panel{border:1px solid var(--line);border-radius:14px;margin:0 0 16px;
  background:var(--card);box-shadow:var(--shadow-sm);overflow:hidden}
details.steps-panel>summary{cursor:pointer;font-weight:600;font-size:15.5px;
  padding:14px 18px;list-style:none}
details.steps-panel>summary:hover{background:var(--soft)}
details.steps-panel>summary::-webkit-details-marker{display:none}
details.steps-panel>summary::before{content:"+ ";font-family:var(--mono);color:var(--primary)}
details.steps-panel[open]>summary::before{content:"\2013  "}
details.steps-panel .steps-body{border-top:1px solid var(--line);padding:8px 18px 16px}
.sharerow{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-top:4px}
.histchips{display:flex;gap:6px;flex-wrap:wrap;align-items:center}
.histchips .hl{font-size:12px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--muted)}
.chip{font-family:var(--mono);font-size:12.5px;border:1px solid var(--line-strong);border-radius:999px;
  background:var(--card);color:var(--ink-soft);padding:5px 11px;cursor:pointer;max-width:210px;
  overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.chip:hover{border-color:var(--primary);color:var(--primary)}

/* ---------- tables & formulas ---------- */
table{border-collapse:collapse;width:100%;font-size:15px}
th,td{border:1px solid var(--line);padding:8px 11px;text-align:left}
th{background:var(--soft);font-weight:600}
td{font-family:var(--mono);font-size:14.5px;font-variant-numeric:tabular-nums}
.table-scroll{overflow-x:auto;margin:16px 0;border:1px solid var(--line);
  border-radius:var(--r-md);background:var(--card);box-shadow:var(--shadow-sm)}
.table-scroll table{border-collapse:collapse}
.table-scroll th,.table-scroll td{border:none;border-bottom:1px solid var(--line)}
.table-scroll th{background:var(--soft);color:var(--ink-soft);font-size:13.5px}
.table-scroll tr:last-child>td{border-bottom:none}
.formula{background:var(--code-bg);color:var(--code-ink);font-family:var(--mono);
  border-radius:var(--r-md);padding:18px 22px;margin:16px 0;font-size:16.5px;
  overflow-x:auto;white-space:nowrap}
.formula .fl{display:block;font-family:var(--sans);font-size:11.5px;letter-spacing:.07em;
  text-transform:uppercase;color:var(--code-label);margin-bottom:6px}
.example{border:1px solid var(--line);border-left:4px solid var(--primary);
  background:var(--card);border-radius:var(--r-md);box-shadow:var(--shadow-sm);
  padding:16px 20px;margin:16px 0}
.example .etag{font-size:11.5px;font-weight:700;letter-spacing:.07em;text-transform:uppercase;color:var(--primary)}
.mistake{border:1px solid var(--warn-line);border-left:4px solid var(--warn-accent);
  background:var(--warn-bg);border-radius:var(--r-md);padding:16px 20px;margin:16px 0}

/* ---------- article & faq ---------- */
article{max-width:none;background:var(--card);border:1px solid var(--line);
  border-radius:var(--r-lg);box-shadow:var(--shadow);
  padding:30px 34px 26px;margin:0 0 10px}
article>:first-child{margin-top:0}
article p,article li{font-size:17px}
article ul,article ol{margin:0 0 14px;padding-left:24px}
article li{margin-bottom:6px}
.faq{border:1px solid var(--line);border-radius:var(--r-md);background:var(--card);
  box-shadow:var(--shadow-sm);padding:16px 18px 8px;margin:12px 0}
.faq h3{margin:0 0 6px;font-size:16.5px;font-weight:600}

/* ---------- cards & hubs ---------- */
.hub-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:16px;margin:18px 0}
.hub-card{border:1px solid var(--line);background:var(--card);border-radius:var(--r-lg);
  box-shadow:var(--shadow-sm);padding:20px;
  transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease}
.hub-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg);border-color:var(--primary-line)}
.hub-card h3{margin:0 0 6px;font-size:18px;font-weight:700}
.hub-card h3 a{color:var(--ink);text-decoration:none}
.hub-card h3 a:hover{color:var(--primary)}
.hub-card p{font-size:15px;color:var(--ink-soft);margin:0}
.related{margin:36px 0 10px}
.related>h2{color:var(--ink)}
.rgrid-links{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:12px}
.rlink{border:1px solid var(--line);background:var(--card);border-radius:var(--r-md);
  box-shadow:var(--shadow-sm);padding:15px 17px;text-decoration:none;
  color:var(--ink);font-weight:600;font-size:16px;display:block;
  transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease}
.rlink small{display:block;font-weight:400;color:var(--muted);font-size:13.5px;margin-top:3px}
.rlink:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg);border-color:var(--primary-line);color:var(--primary)}

/* ---------- footer ---------- */
footer.site{border-top:1px solid var(--line);margin-top:64px;padding:36px 0 44px;background:#fff}
footer.site .cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:22px}
footer.site h4{margin:0 0 10px;font-size:15px;font-weight:700;color:var(--ink)}
footer.site ul{list-style:none;margin:0;padding:0}
footer.site li{margin-bottom:7px}
footer.site a{color:var(--ink-soft);text-decoration:none;font-size:15px}
footer.site a:hover{color:var(--primary);text-decoration:underline}
footer.site p{font-size:13.5px;color:var(--muted);max-width:60em}

/* ---------- mobile ---------- */
@media (max-width:680px){
  body{font-size:16px}
  h1{font-size:30px;margin-top:20px}
  body.home h1{font-size:38px;margin-top:26px}
  body.home .lede{font-size:16.5px}
  h2{font-size:23px}
  .lede{font-size:17px}
  header.site .wrap{gap:14px;flex-wrap:wrap}
  nav.main{gap:2px;margin:0}
  nav.main a{font-size:14px;padding:6px 8px}
  .nav-cta{margin-left:auto;padding:6px 14px;font-size:14px}
  .toolcard{padding:20px 16px 18px}
  article{padding:20px 18px 16px}
  .rv{font-size:19px}
  .rcell.hero .rv{font-size:23px}
  .btn{width:100%;padding:14px}
  .btnrow .btn-ghost{flex:1}
  .formula{font-size:14.5px}
  .hub-grid{grid-template-columns:1fr}
  .radio-row label{padding:8px 13px}
}