/* Grade — 2026 design system (hue-rotated from approved pilot). Same class names, bold-modern skin.
   Light + dark (prefers-color-scheme). Zero external assets. */
:root{
  --green:#0E0BA8; --green-d:#08067A; --ink:#1C1E26; --grey:#61656F;
  --line:rgba(14,15,42,.11); --bg:#FCFCFD; --card:#FFFFFF; --gold:#0B7A3C;
  --tint:#F5F6F9; --answer-bg:#F2F4FE; --answer-line:#DBE1FA;
  --hero-grad:linear-gradient(135deg,#08067A 0%,#0E0BA8 55%,#2222C7 100%);
  --page-grad:radial-gradient(1100px 460px at 88% -12%, rgba(34,34,199,.06), transparent 62%);
  --chart-line:#0E0BA8; --chart-line2:#6768B3; --chart-fill:rgba(14,11,168,.16); --chart-fill2:rgba(120,122,190,.35);
  --chart-grid:rgba(14,15,42,.08); --chart-text:#7D928C;
  --radius:18px;
  --shadow:0 1px 2px rgba(6,6,50,.06),0 8px 30px rgba(6,6,50,.10);
  --shadow-lift:0 2px 6px rgba(6,6,50,.08),0 16px 44px rgba(6,6,50,.16);
  --focus:0 0 0 4px rgba(14,11,168,.18);
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --green:#7D96F2; --green-d:#9FB1F6; --ink:#E9EAEE; --grey:#A2A6B0;
    --line:rgba(232,234,244,.13); --bg:#15161B; --card:#1C1E25; --gold:#4CC97E;
    --tint:#1D1F26; --answer-bg:#1C2133; --answer-line:#2E3A5C;
    --hero-grad:linear-gradient(135deg,#0B0A3A 0%,#0D0D5F 55%,#11118D 100%);
    --page-grad:radial-gradient(1100px 460px at 88% -12%, rgba(43,44,212,.08), transparent 62%);
    --chart-line:#2B2CD4; --chart-line2:#4A4B8D; --chart-fill:rgba(43,44,212,.15); --chart-fill2:rgba(74,75,141,.35);
    --chart-grid:rgba(232,234,244,.08); --chart-text:#7D8095;
    --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 34px rgba(0,0,0,.45);
    --shadow-lift:0 2px 8px rgba(0,0,0,.5),0 18px 48px rgba(0,0,0,.55);
    --focus:0 0 0 4px rgba(43,44,212,.22);
  }
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  color:var(--ink);background:var(--bg);background-image:var(--page-grad);background-attachment:scroll;
  line-height:1.55;-webkit-font-smoothing:antialiased}
a{color:var(--green-d);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:1060px;margin:0 auto;padding:0 18px}

/* ---------- header: calm, near-zero chrome (Just Math) ---------- */
.site-head{background:var(--bg);color:var(--ink);position:sticky;top:0;z-index:50;
  border-bottom:1px solid var(--line);backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px)}
.site-head .wrap{display:flex;align-items:center;justify-content:space-between;height:56px}
.brand{font-weight:800;color:var(--ink);font-size:18px;letter-spacing:-.3px}
.brand span{color:var(--green-d);opacity:1;font-weight:700}
.nav a{color:var(--grey);margin-left:18px;font-size:14px;font-weight:650;transition:color .15s}
.nav a:hover{color:var(--green-d);text-decoration:none}

.breadcrumb{font-size:12.5px;color:var(--grey);padding:18px 0 0}
.breadcrumb a{color:var(--grey)}

h1{font-size:clamp(27px,4.4vw,36px);line-height:1.1;margin:8px 0 8px;letter-spacing:-.7px;color:var(--ink)}
.intro{color:var(--grey);max-width:760px;margin:0 0 20px;font-size:16.5px;line-height:1.6}
.intro strong,.intro em{color:var(--ink);font-weight:650;font-style:normal}

/* ---------- ad slots (subtle) ---------- */
.ad{background:repeating-linear-gradient(45deg,transparent,transparent 10px,var(--line) 10px,var(--line) 11px);
  border:1px dashed var(--line);border-radius:12px;color:var(--grey);opacity:.7;font-size:11px;text-align:center;
  padding:10px;margin:16px 0;letter-spacing:.5px}
.ad.lb{min-height:90px;display:flex;align-items:center;justify-content:center}
.ad.rail{min-height:250px;display:flex;align-items:center;justify-content:center}

/* ---------- layout + glass panels ---------- */
.calc-grid{display:grid;grid-template-columns:1fr 1.15fr;gap:18px;align-items:start}
.panel{background:var(--card);border:1.5px solid var(--line);border-radius:14px;padding:20px}
.panel h2{font-size:12px;margin:0 0 14px;text-transform:uppercase;letter-spacing:1px;color:var(--grey);font-weight:700}

/* ---------- inputs ---------- */
.field{margin-bottom:15px}
.field label{display:block;font-size:13px;font-weight:700;margin-bottom:6px}
.field .help{font-weight:500;color:var(--grey);font-size:11.5px;margin-left:4px}
.control{position:relative;display:flex;align-items:center}
.control .pre,.control .suf{position:absolute;color:var(--grey);font-size:14px;pointer-events:none}
.control .pre{left:13px}.control .suf{right:13px}
input[type=number],input[type=date],input[type=time],select{width:100%;padding:11px 13px;font-size:15px;
  border:1.5px solid var(--line);border-radius:10px;background:var(--tint);color:var(--ink);
  transition:border-color .15s, box-shadow .15s;font-family:inherit;font-variant-numeric:tabular-nums}
.control.has-pre input{padding-left:28px}
.control.has-suf input{padding-right:34px}
input:focus,select:focus{outline:none;border-color:var(--green);box-shadow:var(--focus)}
input[type=range]{width:100%;accent-color:var(--green);margin-top:6px}

/* ---------- results ---------- */
.results-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-bottom:8px}
.rcard{background:var(--tint);border:1px solid var(--line);border-radius:12px;padding:13px;text-align:center}
.rcard .v{font-size:20px;font-weight:800;color:var(--green-d);letter-spacing:-.5px;font-variant-numeric:tabular-nums}
.rcard .l{font-size:11px;color:var(--grey);margin-top:3px}
/* the answer — warm indigo tint, not a saturated card */
.rcard.hero{background:var(--answer-bg);border:1.5px solid var(--answer-line);border-radius:14px;padding:20px 16px}
.rcard.hero .v{color:var(--green-d);font-size:clamp(38px,8vw,50px);font-weight:800;letter-spacing:-1.5px;line-height:1.05}
.rcard.hero .l{color:var(--grey);font-size:13px;margin-top:4px;font-weight:600}
/* transparent worked formula — here's the math with your numbers */
.work{font-family:ui-monospace,Menlo,monospace;font-size:12.5px;color:var(--grey);
  background:var(--tint);border:1px dashed var(--answer-line);border-radius:10px;
  padding:11px 13px;margin:4px 0 12px;overflow-x:auto;white-space:nowrap;line-height:1.5}

canvas#chart{width:100%;height:250px;margin-top:16px;display:block}
.legend{display:flex;gap:16px;justify-content:center;font-size:12px;color:var(--grey);margin-top:8px}
.legend i{display:inline-block;width:11px;height:11px;border-radius:3px;margin-right:5px;vertical-align:-1px}

.btnrow{display:flex;gap:9px;flex-wrap:wrap;margin-top:16px}
.btn{border:1.5px solid var(--line);color:var(--green-d);background:transparent;padding:9px 15px;border-radius:10px;
  font-size:13px;font-weight:700;cursor:pointer;font-family:inherit;transition:border-color .15s, background .15s, color .15s}
.btn:hover{border-color:var(--green);background:var(--answer-bg);color:var(--green-d)}
.btn.primary{background:var(--green-d);border:1.5px solid var(--green-d);color:#FFFFFF}
.btn.primary:hover{filter:brightness(1.08);background:var(--green-d);color:#FFFFFF}
.copied{color:var(--green-d);font-size:12px;font-weight:700;align-self:center}

/* ---------- schedule table ---------- */
details.sched{margin-top:16px}
details.sched summary{cursor:pointer;font-weight:700;color:var(--green-d);font-size:14px;padding:6px 0}
table.sched{width:100%;border-collapse:collapse;font-size:12.5px;margin-top:8px}
table.sched th,table.sched td{padding:8px;text-align:right;border-bottom:1px solid var(--line)}
table.sched th:first-child,table.sched td:first-child{text-align:left}
table.sched thead th{color:var(--grey);font-size:11px;text-transform:uppercase;letter-spacing:.5px}
table.sched tbody tr{transition:background .12s}
table.sched tbody tr:hover{background:var(--bg)}

/* ---------- content sections ---------- */
.section{background:var(--card);border:1.5px solid var(--line);border-radius:14px;padding:22px;margin:18px 0}
.section h2{font-size:20px;margin:0 0 10px;letter-spacing:-.3px}
.section p{line-height:1.62}
.formula{background:var(--tint);border:1px solid var(--line);border-radius:10px;padding:13px 15px;
  font-family:ui-monospace,Menlo,monospace;font-size:14px;overflow-x:auto;color:var(--grey)}
.faq{border-top:1px solid var(--line);padding:13px 0}
.faq:last-child{padding-bottom:0}
.faq summary{cursor:pointer;font-weight:700;font-size:15px}
.faq summary:hover{color:var(--green-d)}
.faq p{color:var(--grey);margin:8px 0 0}
.related{display:flex;flex-wrap:wrap;gap:10px;margin-top:6px}
.related a{background:var(--bg);border:1px solid var(--line);border-radius:11px;padding:10px 14px;font-weight:650;
  font-size:14px;color:var(--ink);transition:transform .13s, border-color .13s, box-shadow .15s}
.related a:hover{border-color:var(--green);transform:translateY(-2px);box-shadow:var(--shadow);text-decoration:none;color:var(--green-d)}

/* ---------- footer ---------- */
footer{color:var(--grey);font-size:12.5px;text-align:center;padding:30px 0 38px}
footer .flinks{display:flex;gap:18px;justify-content:center;flex-wrap:wrap;margin-bottom:9px}
footer .flinks a{font-weight:650;font-size:13px;color:var(--grey);transition:color .15s}
footer .flinks a:hover{color:var(--green-d);text-decoration:none}
footer p{margin:0}

/* legal pages */
.legal{max-width:760px}
.legal h2{font-size:19px;margin:22px 0 8px}
.legal p,.legal li{font-size:14.5px;line-height:1.68}

/* motion preferences */
@media (prefers-reduced-motion: reduce){
  *{transition:none!important;animation:none!important}
  html{scroll-behavior:auto}
}
@media(max-width:760px){
  .calc-grid{grid-template-columns:1fr}
  .results-cards{grid-template-columns:1fr 1fr}
}

:root[data-theme="dark"]{
    --green:#7D96F2; --green-d:#9FB1F6; --ink:#E9EAEE; --grey:#A2A6B0;
    --line:rgba(232,234,244,.13); --bg:#15161B; --card:#1C1E25; --gold:#4CC97E;
    --tint:#1D1F26; --answer-bg:#1C2133; --answer-line:#2E3A5C;
    --hero-grad:linear-gradient(135deg,#0B0A3A 0%,#0D0D5F 55%,#11118D 100%);
    --page-grad:radial-gradient(1100px 460px at 88% -12%, rgba(43,44,212,.08), transparent 62%);
    --chart-line:#2B2CD4; --chart-line2:#4A4B8D; --chart-fill:rgba(43,44,212,.15); --chart-fill2:rgba(74,75,141,.35);
    --chart-grid:rgba(232,234,244,.08); --chart-text:#7D8095;
    --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 34px rgba(0,0,0,.45);
    --shadow-lift:0 2px 8px rgba(0,0,0,.5),0 18px 48px rgba(0,0,0,.55);
    --focus:0 0 0 4px rgba(43,44,212,.22);
}

/* dark mode toggle — sits on the calm light header */
.mode-btn{background:transparent;border:1px solid var(--line);color:var(--grey);
  width:32px;height:32px;border-radius:9px;cursor:pointer;font-size:15px;line-height:1;margin-left:18px;
  transition:border-color .15s, color .15s, transform .12s;vertical-align:middle}
.mode-btn:hover{border-color:var(--green);color:var(--green-d);transform:translateY(-1px)}
/* article shell */
.qa-box{background:var(--hero-grad);color:#fff;border-radius:14px;padding:16px 18px;font-size:16px;line-height:1.6;box-shadow:var(--shadow)}
.qa-box strong{opacity:.85}
.calc-embed{width:100%;height:640px;border:1px solid var(--line);border-radius:14px;background:var(--bg)}
.embed .site-head,.embed .ad,.embed .section,.embed footer,.embed .breadcrumb,.embed h1,.embed .intro,.embed .sticky-answer,.embed .trustline{display:none!important}
.embed main{padding-top:8px}

.trustline{font-size:12.5px;color:var(--grey);text-align:center;margin:14px 0 0;opacity:.9;max-width:760px}

/* ---------- scenario tabs (RogerHub parity) ---------- */
.scenario-tabs{display:flex;flex-wrap:wrap;gap:7px;margin:0 0 12px}
.scenario-tab{border:1.5px solid var(--line);background:var(--tint);color:var(--grey);
  padding:7px 12px;border-radius:9px;font-size:12.5px;font-weight:700;cursor:pointer;font-family:inherit;
  transition:border-color .14s, color .14s, background .14s}
.scenario-tab:hover{border-color:var(--green);color:var(--green-d)}
.scenario-tab.active{background:var(--answer-bg);border-color:var(--answer-line);color:var(--green-d)}
.scenario-hint{font-size:13px;color:var(--grey);margin:0 0 14px;line-height:1.55;
  border-left:2px solid var(--answer-line);padding-left:11px}

/* ---------- sticky mobile answer bar ("You need 94.7%") ---------- */
.sticky-answer{display:none}
@media(max-width:760px){
  .sticky-answer{display:flex;position:fixed;left:0;right:0;bottom:0;z-index:60;
    align-items:center;justify-content:space-between;gap:10px;
    padding:11px 18px calc(11px + env(safe-area-inset-bottom));
    background:var(--card);border-top:1.5px solid var(--answer-line);
    box-shadow:0 -6px 20px rgba(6,6,50,.10);
    transform:translateY(110%);transition:transform .22s ease}
  .sticky-answer.show{transform:translateY(0)}
  .sticky-answer .sa-label{font-size:12.5px;color:var(--grey);font-weight:600}
  .sticky-answer .sa-val{font-size:22px;font-weight:800;color:var(--green-d);
    letter-spacing:-.5px;font-variant-numeric:tabular-nums}
  body{padding-bottom:60px}
  .embed .sticky-answer{display:none!important}
}