/* CalcBeam theme v1 - original design. Teal accent, system fonts, card-based layout.
   Theming via data-theme="dark" and data-contrast="high" on <html>. */
:root{
  --accent:#0d9488;          /* distinctive teal, not generic blue */
  --accent-deep:#0b6f64;
  --accent-soft:#e3f5f2;
  --accent-ink:#075e55;
  --amber:#d97706;
  --bg:#f6f9f8;
  --card:#ffffff;
  --fg:#1c2624;
  --muted:#5c6f6b;
  --line:#dfe8e6;
  --hero-grad:linear-gradient(135deg,#0b6f64 0%,#0d9488 55%,#14b8a6 100%);
  --radius:14px;
  --shadow:0 2px 10px rgba(11,111,100,.08);
  --shadow-lg:0 10px 30px rgba(11,111,100,.14);
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans",sans-serif;
  --mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;
}
[data-theme="dark"]{
  --bg:#0d1514;
  --card:#14201e;
  --fg:#e9f2f0;
  --muted:#9fb5b1;
  --line:#263a37;
  --accent:#2dd4bf;
  --accent-deep:#5eead4;
  --accent-soft:#143a36;
  --accent-ink:#99f6e4;
  --hero-grad:linear-gradient(135deg,#083c37 0%,#0b6f64 60%,#0d9488 100%);
  --shadow:0 2px 10px rgba(0,0,0,.35);
  --shadow-lg:0 10px 30px rgba(0,0,0,.45);
}
[data-contrast="high"]{
  --bg:#ffffff;
  --card:#ffffff;
  --fg:#000000;
  --muted:#222222;
  --line:#000000;
  --accent:#005a4e;
  --accent-deep:#00453d;
  --accent-soft:#ffffff;
  --accent-ink:#003a33;
  --hero-grad:none;
  --shadow:none;
  --shadow-lg:none;
}
[data-contrast="high"][data-theme="dark"]{
  --bg:#000000;
  --card:#000000;
  --fg:#ffffff;
  --muted:#e8e8e8;
  --line:#ffffff;
  --accent:#5eead4;
  --accent-soft:#000000;
  --accent-ink:#ccfbf1;
}

/* ---------- base ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--fg);font-family:var(--font);
  font-size:1.02rem;line-height:1.65}
img,svg{max-width:100%}
a{color:var(--accent-ink);text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1.5px}
[data-theme="dark"] a{color:var(--accent)}
a:hover{color:var(--accent-deep)}
h1,h2,h3{line-height:1.25;letter-spacing:-.01em;margin:1.6em 0 .6em}
h1{font-size:clamp(1.7rem,4.5vw,2.4rem);margin-top:.4em}
h2{font-size:1.35rem}
h3{font-size:1.12rem}
p{margin:.7em 0}
ul.tight,ol.tight{padding-left:1.4em}
ul.tight li,ol.tight li{margin:.35em 0}
.meta{color:var(--muted);font-size:.9rem}
.skip{position:absolute;left:-9999px;top:auto;width:1px;height:1px;overflow:hidden}
.skip:focus{left:8px;top:8px;width:auto;height:auto;background:var(--card);color:var(--fg);
  padding:.6em 1em;border:2px solid var(--accent);border-radius:8px;z-index:200}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:4px}
[data-contrast="high"] :focus-visible{outline:3px solid #ffbf00;outline-offset:3px}

/* ---------- header ---------- */
.hdr{position:sticky;top:0;z-index:100;background:var(--card);border-bottom:1px solid var(--line);
  box-shadow:var(--shadow)}
.hdr .bar{max-width:1180px;margin:0 auto;padding:.55rem 1rem;display:flex;align-items:center;gap:.6rem}
.brand{display:flex;align-items:center;gap:.55rem;text-decoration:none;font-weight:800;font-size:1.25rem;
  color:var(--fg);letter-spacing:-.02em}
.brand:hover{color:var(--accent-deep)}
.brand svg{flex:0 0 auto}
.navsp{flex:1}
.navlinks{display:flex;align-items:center;gap:.35rem}
.navlinks>a,.navdrop>summary{color:var(--fg);text-decoration:none;font-weight:600;font-size:.96rem;
  padding:.5rem .7rem;border-radius:9px;cursor:pointer;list-style:none}
.navlinks>a:hover,.navdrop>summary:hover{background:var(--accent-soft);color:var(--accent-ink)}
.navdrop{position:relative}
.navdrop>summary::-webkit-details-marker{display:none}
.navdrop>summary::after{content:" ▾";font-size:.8em}
.navdrop .dropmenu{position:absolute;top:calc(100% + 6px);left:0;min-width:250px;background:var(--card);
  border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow-lg);padding:.5rem;z-index:120}
.navdrop .dropmenu a{display:flex;align-items:center;gap:.6rem;padding:.5rem .7rem;border-radius:8px;
  color:var(--fg);text-decoration:none;font-size:.95rem}
.navdrop .dropmenu a:hover{background:var(--accent-soft)}
.navdrop .dropmenu .cicon{flex:0 0 1.9em}
.iconbtn{display:inline-flex;align-items:center;justify-content:center;width:2.5rem;height:2.5rem;
  border:1px solid var(--line);background:var(--card);color:var(--fg);border-radius:10px;cursor:pointer;
  font-size:1.05rem;line-height:1}
.iconbtn:hover{background:var(--accent-soft);border-color:var(--accent)}
.iconbtn[aria-pressed="true"]{background:var(--accent-soft);border-color:var(--accent);color:var(--accent-ink)}
.iconbtn svg{width:1.2rem;height:1.2rem}

/* ---------- layout ---------- */
.wrap{max-width:1180px;margin:0 auto;padding:1rem 1rem 2.5rem}
.main-narrow .wrap{max-width:860px}

/* ---------- breadcrumb ---------- */
.crumb{font-size:.88rem;color:var(--muted);margin:.6rem 0}
.crumb a{color:var(--muted);text-decoration:none}
.crumb a:hover{color:var(--accent-ink);text-decoration:underline}
.crumb [aria-current]{color:var(--fg);font-weight:600}

/* ---------- hero ---------- */
.hero{background:var(--hero-grad);color:#fff;border-radius:0 0 26px 26px;padding:3rem 1.25rem 3.4rem;
  text-align:center}
[data-contrast="high"] .hero{border-bottom:4px solid #000}
.hero-inner{max-width:760px;margin:0 auto}
.hero h1{color:#fff;font-size:clamp(2rem,6vw,3rem);margin:0 0 .6rem;letter-spacing:-.02em}
.hero p.sub{color:rgba(255,255,255,.92);font-size:1.12rem;margin:0 auto 1.4rem;max-width:34em}
.hero .sub a{color:#fff}
.searchbox{position:relative;max-width:560px;margin:0 auto}
.searchbox input[type="search"]{width:100%;padding:1rem 1.2rem 1rem 3rem;font-size:1.08rem;border:none;
  border-radius:999px;background:#fff;color:#123;box-shadow:var(--shadow-lg)}
[data-theme="dark"] .searchbox input[type="search"]{background:#fff;color:#111}
.searchbox .mag{position:absolute;left:1rem;top:50%;transform:translateY(-50%);width:1.2rem;height:1.2rem;
  color:var(--accent-deep);pointer-events:none}
.sugg{position:absolute;top:calc(100% + 6px);left:0;right:0;background:var(--card);border:1px solid var(--line);
  border-radius:12px;box-shadow:var(--shadow-lg);overflow:hidden;text-align:left;z-index:60}
.sugg a{display:block;padding:.6rem 1rem;color:var(--fg);text-decoration:none;font-size:.96rem}
.sugg a:hover{background:var(--accent-soft)}
.chips{display:flex;flex-wrap:wrap;gap:.5rem;justify-content:center;margin-top:1.1rem}
.chip{display:inline-block;padding:.42rem .95rem;border-radius:999px;background:rgba(255,255,255,.16);
  color:#fff;text-decoration:none;font-size:.92rem;font-weight:600;border:1px solid rgba(255,255,255,.35)}
.chip:hover{background:#fff;color:var(--accent-deep)}
[data-contrast="high"] .chip{border:2px solid #fff}

/* ---------- section headings ---------- */
.sec-head{display:flex;align-items:baseline;justify-content:space-between;gap:1rem;margin:2.6rem 0 1rem}
.sec-head h2{margin:0}
.sec-head a{font-size:.95rem;white-space:nowrap}

/* ---------- cards & grids ---------- */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:1rem}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);padding:1.15rem 1.25rem}
.card:hover{border-color:var(--accent)}
.tcard{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);padding:1.1rem 1.2rem;display:flex;flex-direction:column;gap:.35rem}
.tcard:hover{border-color:var(--accent);box-shadow:var(--shadow-lg)}
.tcard>a{font-weight:700;text-decoration:none;color:var(--fg);font-size:1.05rem}
.tcard>a:hover{color:var(--accent-ink)}
[data-theme="dark"] .tcard>a:hover{color:var(--accent)}
.tcard p{margin:0;color:var(--muted);font-size:.93rem}
.tcard .kicker{font-size:.78rem;font-weight:700;text-transform:uppercase;letter-spacing:.06em;color:var(--accent-ink)}
.catgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(170px,1fr));gap:1rem}
.catcard{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);padding:1.2rem 1rem;text-align:center;text-decoration:none;color:var(--fg);
  display:flex;flex-direction:column;align-items:center;gap:.55rem}
.catcard:hover{border-color:var(--accent);transform:translateY(-2px);box-shadow:var(--shadow-lg)}
.cicon{width:3rem;height:3rem;border-radius:50%;background:var(--accent-soft);color:var(--accent-ink);
  display:inline-flex;align-items:center;justify-content:center;font-size:1.5rem;line-height:1}
[data-theme="dark"] .cicon{color:var(--accent)}
.catcard .cname{font-weight:700;font-size:.98rem}
.catcard .n{font-size:.83rem;color:var(--muted)}

/* ---------- why-us / hubs ---------- */
.why{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:1.8rem;
  margin:2.6rem 0;box-shadow:var(--shadow)}
.why .cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:1.2rem;margin-top:1.2rem}
.why .pt h3{margin:.4rem 0;font-size:1.05rem}
.why .pt p{margin:0;color:var(--muted);font-size:.95rem}
.hubstrip{background:var(--accent-soft);border:1px solid var(--line);border-radius:18px;padding:1.6rem 1.8rem;
  margin:2.4rem 0}
.hubstrip h2{margin-top:0}
.hubgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:.7rem}
.hubgrid a{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:.65rem .9rem;
  text-decoration:none;color:var(--fg);font-weight:600;font-size:.95rem}
.hubgrid a:hover{border-color:var(--accent)}

/* ---------- calculator tool card ---------- */
.calc-card{background:var(--card);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow-lg);
  padding:1.4rem;margin:1.4rem 0 2rem;overflow:hidden}
[data-contrast="high"] .calc-card{border:2px solid #000}
.fgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1rem}
.field{display:flex;flex-direction:column;gap:.35rem}
.field label{font-weight:600;font-size:.92rem}
.calc-input{width:100%;padding:.65rem .8rem;font-size:1rem;font-family:var(--font);color:var(--fg);
  background:var(--bg);border:1.5px solid var(--line);border-radius:10px}
.calc-input:focus{border-color:var(--accent);outline:2px solid var(--accent);outline-offset:1px}
select.calc-input,textarea.calc-input{background:var(--bg)}
input[type="range"].calc-range{width:100%;accent-color:var(--accent);margin:.2rem 0 0}
.rangewrap{display:flex;flex-direction:column;gap:.1rem}
.rangeval{font-family:var(--mono);font-size:.9rem;color:var(--muted)}
.chk{display:flex;align-items:center;gap:.6rem;padding:.4rem 0}
.chk input{width:1.15rem;height:1.15rem;accent-color:var(--accent)}
.chk label{font-weight:600;font-size:.95rem}
.tool-actions{display:flex;flex-wrap:wrap;gap:.6rem;margin:1.1rem 0 .4rem}
.btn{display:inline-flex;align-items:center;gap:.5rem;padding:.6rem 1.15rem;border-radius:10px;
  border:1.5px solid var(--accent);background:var(--accent);color:#fff;font-weight:700;font-size:.95rem;
  cursor:pointer;text-decoration:none;font-family:var(--font)}
.btn:hover{background:var(--accent-deep);border-color:var(--accent-deep);color:#fff}
.btn.ghost{background:transparent;color:var(--accent-ink);border-color:var(--accent)}
.btn.ghost:hover{background:var(--accent-soft)}
[data-theme="dark"] .btn.ghost{color:var(--accent)}
.share-note{font-size:.85rem;color:var(--muted)}

/* ---------- result box ---------- */
.result-box{background:var(--accent-soft);border:2px solid var(--accent);border-radius:14px;
  padding:1.1rem 1.25rem;margin-top:1rem}
.res-main{font-size:clamp(1.5rem,4vw,2.1rem);font-weight:800;letter-spacing:-.01em;color:var(--accent-ink);
  font-family:var(--mono)}
[data-theme="dark"] .res-main{color:var(--accent)}
.res-note{margin-top:.4rem;font-size:.93rem;color:var(--muted)}
table.res-table{width:100%;border-collapse:collapse;margin-top:.9rem;font-size:.95rem}
table.res-table th,table.res-table td{text-align:left;padding:.55rem .7rem;border-bottom:1px solid var(--line)}
table.res-table tr:last-child td{border-bottom:none}
table.res-table td:last-child,table.res-table th:last-child{text-align:right;font-family:var(--mono);white-space:nowrap}
.chart{margin-top:1.2rem}
.chart svg{display:block;max-width:640px;width:100%;height:auto}
.chart .chart-title{font-weight:700;font-size:.95rem;margin-bottom:.4rem}
.chart .legend{display:flex;flex-wrap:wrap;gap:.6rem;font-size:.83rem;color:var(--muted);margin-top:.4rem}
.chart .swatch{display:inline-block;width:.8em;height:.8em;border-radius:3px;margin-right:.3em;vertical-align:baseline}

/* ---------- content sections as cards ---------- */
.sect{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);padding:1.3rem 1.5rem;margin:1.2rem 0}
.sect>h2:first-child{margin-top:0}
.formula{font-family:var(--mono);background:var(--bg);border:1px solid var(--line);border-radius:10px;
  padding:.9rem 1.1rem;overflow-x:auto;font-size:1.02rem}
.example{background:var(--bg);border-left:4px solid var(--accent);border-radius:0 10px 10px 0;
  padding:.9rem 1.1rem;margin:.8rem 0}
.disclaimer{border:1.5px dashed var(--amber);background:#fff8ec;border-radius:12px;padding:1rem 1.2rem;margin:1.2rem 0}
[data-theme="dark"] .disclaimer{background:#2a2013}
[data-contrast="high"] .disclaimer{background:#fff;border:2px dashed #000}
.disclaimer strong{color:var(--amber)}

/* ---------- FAQ accordion ---------- */
.faq{background:var(--card);border:1px solid var(--line);border-radius:12px;margin:.6rem 0;box-shadow:var(--shadow)}
.faq summary{cursor:pointer;padding:.9rem 1.1rem;font-weight:700;list-style:none;display:flex;gap:.6rem;align-items:center}
.faq summary::-webkit-details-marker{display:none}
.faq summary::before{content:"+";flex:0 0 1.5em;height:1.5em;border-radius:50%;background:var(--accent-soft);
  color:var(--accent-ink);display:inline-flex;align-items:center;justify-content:center;font-weight:800}
.faq[open] summary::before{content:"–"}
.faq summary:hover{background:var(--accent-soft);border-radius:12px}
.faq>div{padding:0 1.1rem 1rem 3.1rem;color:var(--muted)}
.faq>div p:first-child{margin-top:.2rem}

/* ---------- guides / blog CTA ---------- */
.cta-box{background:var(--hero-grad);color:#fff;border-radius:14px;padding:1.4rem 1.6rem;margin:1.6rem 0;
  display:flex;flex-wrap:wrap;align-items:center;gap:1rem;justify-content:space-between}
[data-contrast="high"] .cta-box{border:4px solid #000}
.cta-box p{margin:0;font-weight:600;font-size:1.05rem;max-width:32em}
.cta-box .btn{background:#fff;color:var(--accent-deep);border-color:#fff}
.cta-box .btn:hover{background:var(--accent-soft)}

/* ---------- footer ---------- */
.ftr{background:var(--card);border-top:1px solid var(--line);margin-top:2.5rem}
.ftr .cols{max-width:1180px;margin:0 auto;padding:2.2rem 1rem 1rem;display:grid;
  grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:1.6rem}
.ftr h3{font-size:.85rem;text-transform:uppercase;letter-spacing:.07em;color:var(--muted);margin:0 0 .7rem}
.ftr ul{list-style:none;margin:0;padding:0}
.ftr li{margin:.32rem 0}
.ftr a{color:var(--muted);text-decoration:none;font-size:.93rem}
.ftr a:hover{color:var(--accent-ink);text-decoration:underline}
.ftr .brandline{font-weight:800;font-size:1.1rem;color:var(--fg);margin-bottom:.5rem}
.ftr .fine{max-width:1180px;margin:0 auto;padding:1rem;border-top:1px solid var(--line);
  font-size:.83rem;color:var(--muted);display:flex;flex-wrap:wrap;gap:1rem;justify-content:space-between}

/* ---------- misc ---------- */
.pill{display:inline-block;font-size:.78rem;font-weight:700;background:var(--accent-soft);
  color:var(--accent-ink);border-radius:999px;padding:.2rem .7rem;text-transform:uppercase;letter-spacing:.05em}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ---------- responsive ---------- */
@media (max-width:720px){
  .navdrop .dropmenu{position:fixed;left:.6rem;right:.6rem;top:3.6rem;max-height:70vh;overflow:auto;columns:1}
  .navlinks>a.hide-sm{display:none}
  .hero{border-radius:0 0 18px 18px;padding:2.2rem 1rem 2.6rem}
  .wrap{padding:1rem .8rem 2rem}
  .sect{padding:1.1rem}
  .fgrid{grid-template-columns:1fr}
}
@media (min-width:721px){
  .navdrop .dropmenu{columns:2;min-width:440px}
}

/* ---------- print: friendly result report ---------- */
.print-head{display:none}
@media print{
  .hdr,.ftr,.hero,.tool-actions,.sugg,.chips,.navdrop,.skip,.cta-box,[data-ads]{display:none !important}
  body{background:#fff;color:#000;font-size:11pt}
  .wrap{max-width:none;padding:0}
  .calc-card,.sect,.faq,.result-box,.card{box-shadow:none;border:1px solid #999;border-radius:0}
  .result-box{background:#fff;border:2px solid #000}
  .res-main{color:#000}
  a{color:#000;text-decoration:none}
  h1{font-size:20pt}
  .print-head{display:block !important;text-align:center;border-bottom:2px solid #000;
    padding-bottom:.5rem;margin-bottom:1rem}
}

/* ---------- v3 additions ---------- */
.with-toc{display:grid;grid-template-columns:minmax(0,1fr) 230px;gap:1.5rem;align-items:start}
.otp{position:sticky;top:76px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:1rem 1.1rem;box-shadow:var(--shadow);font-size:.92rem;max-height:calc(100vh - 100px);overflow:auto}
.otp strong{display:block;margin-bottom:.5rem;color:var(--accent-ink)}
.otp ul{list-style:none;margin:0;padding:0}
.otp li{margin:.3rem 0}
.otp a{color:var(--muted);text-decoration:none}
.otp a:hover{color:var(--accent-ink);text-decoration:underline}
@media(max-width:1000px){.with-toc{grid-template-columns:1fr}.otp{position:static;max-height:none;order:-1}}
.dailytip{background:var(--accent-soft);border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:var(--radius);padding:.9rem 1.2rem;margin:1.2rem 0;color:var(--fg)}
.dailytip strong{color:var(--accent-ink)}
.cotd{margin:0 0 1.2rem}
.cotd-card{border:2px solid var(--accent)}
.aboutsec{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:1.4rem 1.6rem;box-shadow:var(--shadow);margin:0 0 1.4rem}
.aboutsec p{margin:.7rem 0}
.cookiebar{position:fixed;left:1rem;right:1rem;bottom:1rem;z-index:60;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow-lg);padding:1rem 1.2rem;display:flex;gap:1rem;align-items:center;justify-content:space-between;flex-wrap:wrap}
.cookiebar p{margin:0;flex:1;min-width:220px}
.supportbtn{position:fixed;right:1.1rem;bottom:5.2rem;z-index:60;width:52px;height:52px;border-radius:50%;background:var(--accent);color:#fff;display:flex;align-items:center;justify-content:center;box-shadow:var(--shadow-lg)}
.supportbtn svg{width:26px;height:26px}
.supportbtn:hover{background:var(--accent-deep)}
.cmpgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:1rem}
.cmpgrid .res-main{font-size:1.3rem}
.featured{margin-top:1rem;padding-top:1rem;border-top:1px solid var(--line)}
.embed-mode .hdr,.embed-mode .ftr,.embed-mode .cookiebar,.embed-mode .supportbtn,.embed-mode .skip{display:none!important}
.embed-mode .wrap{padding-top:.5rem}
code{background:var(--accent-soft);padding:.1em .4em;border-radius:6px;font-family:var(--mono);font-size:.9em}
@media print{
  .hdr,.ftr,.tool-actions,.otp,.cookiebar,.supportbtn,.dailytip,.cotd,.chips,.sugg{display:none!important}
  .print-head{display:block!important}
  body{background:#fff}
}
@media(max-width:760px){.navlinks>a.hide-md{display:none}}