@import url('https://fonts.googleapis.com/css2?family=Manrope:wght@400;500;600;700;800&family=Space+Grotesk:wght@500;600;700&display=swap');
:root{--bg:#f4f9fd;--surface:#fff;--ink:#123047;--muted:#667d8f;--line:#dcebf5;--blue:#168bd2;--blue2:#e7f4fd;--navy:#0d3550;--max:1100px}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:Manrope,system-ui,sans-serif;line-height:1.55}
a{color:inherit;text-decoration:none}.container{width:min(calc(100% - 36px),var(--max));margin:auto}
header{background:#fff;border-bottom:1px solid var(--line)}.nav{height:74px;display:flex;align-items:center;justify-content:space-between}.logo{font-family:"Space Grotesk";font-weight:700;font-size:21px;display:flex;align-items:center;gap:10px}.logo span{display:grid;place-items:center;width:36px;height:36px;background:var(--blue);color:white;border-radius:9px}.nav nav{display:flex;gap:25px;color:var(--muted);font-size:14px;font-weight:800}.theme-btn{border:1px solid var(--line);background:#fff;color:var(--ink);border-radius:10px;width:40px;height:40px;cursor:pointer}
.hero{position:relative;overflow:hidden;padding:74px 0 68px;background:#fff}.hero:before,.hero:after{content:"";position:absolute;border:2px solid #bfe2f5;transform:rotate(22deg);opacity:.55}.hero:before{width:150px;height:150px;right:8%;top:-65px}.hero:after{width:90px;height:90px;right:18%;bottom:-45px;border-radius:50%}.hero.small{padding:42px 0}.eyebrow{text-transform:uppercase;letter-spacing:.13em;font-size:11px;font-weight:800;color:var(--blue)}h1,h2,h3{font-family:"Space Grotesk";line-height:1.08}h1{font-size:clamp(40px,6vw,70px);letter-spacing:-.045em;margin:12px 0 15px}h1 em{font-style:normal;color:var(--blue)}h2{font-size:35px;letter-spacing:-.035em}h3{font-size:19px;margin:15px 0 7px}p{color:var(--muted);margin:0}.back{display:inline-block;color:var(--muted);font-size:13px;font-weight:800;margin-bottom:20px}
.app{padding:44px 0 70px}.section-head{display:flex;justify-content:space-between;align-items:end;margin-bottom:25px}.section-head h2{margin:8px 0 0}.section-head>p{max-width:360px;text-align:right}
.cards{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}.card{position:relative;overflow:hidden;background:#fff;border:1px solid var(--line);border-radius:18px;padding:26px;min-height:205px;cursor:pointer;box-shadow:0 9px 28px #1d58710a;transition:.18s}.card:after{content:"";position:absolute;right:-30px;bottom:-35px;width:100px;height:100px;border:2px solid #d6edf9;transform:rotate(35deg)}.card:hover{transform:translateY(-3px);border-color:#b7dcef;box-shadow:0 14px 36px #1d587116}.icon{width:48px;height:48px;border-radius:13px;display:grid;place-items:center;background:var(--blue2);color:var(--blue);font:700 22px "Space Grotesk"}.card p{font-size:14px;max-width:390px}.card-link{display:inline-block;margin-top:20px;color:var(--blue);font-weight:800;font-size:13px}
.calculator{background:#fff;border:1px solid var(--line);border-radius:20px;padding:30px;box-shadow:0 12px 38px #1d58710a;max-width:800px;margin:auto}.two{display:grid;grid-template-columns:1fr 1fr;gap:18px}.four{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.field-label{display:block;color:#61798b;font-size:12px;font-weight:800}.field-label input{display:block;width:100%;margin-top:8px;border:1px solid #cfe1ec;border-radius:10px;padding:13px 14px;font:600 16px Manrope;color:var(--ink);outline:none;background:#fff}.field-label input:focus{border-color:var(--blue);box-shadow:0 0 0 3px #168bd218}.primary-btn{margin-top:22px;width:100%;border:0;border-radius:10px;padding:14px;background:var(--blue);color:#fff;font:800 14px Manrope;cursor:pointer}.answer{margin-top:20px;padding:20px;border-radius:13px;background:#f1f8fd;color:#557083;text-align:center}.answer .main{font:700 30px "Space Grotesk";color:var(--ink);margin-bottom:6px}.tabs{display:flex;gap:8px;justify-content:center;margin-bottom:18px;flex-wrap:wrap}.tab{border:1px solid var(--line);background:#fff;border-radius:9px;padding:10px 14px;color:#5e7485;font:700 13px Manrope;cursor:pointer}.tab.active{background:var(--blue);border-color:var(--blue);color:#fff}
.fraction-inputs{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:28px;max-width:620px;margin:0 auto 28px}.fracbox{display:flex;flex-direction:column;align-items:center;gap:9px;color:#6b8292;font-size:13px;font-weight:750}.fracbox input{width:110px;text-align:center;font-size:24px;font-weight:700;padding:10px 8px;border:1px solid #cfe1ec;border-radius:10px;background:#fff}.fracbox hr{width:110px;border:0;border-top:3px solid var(--ink);margin:0}.operator{font-size:32px;font-weight:800}.frac-label{min-height:20px}.fraction{display:inline-flex;vertical-align:middle;flex-direction:column;align-items:center;line-height:1.05;margin:0 .12em;min-width:1.2em}.fraction .top{padding:0 .18em;border-bottom:2px solid currentColor}.fraction .bottom{padding:.12em .18em 0}.mathline{font-size:clamp(22px,4vw,34px);font-weight:700;display:flex;align-items:center;justify-content:center;gap:.12em;flex-wrap:wrap}.steps{text-align:left;border-top:1px solid var(--line);margin-top:18px;padding-top:15px}.steps div{padding:7px 0}
.dark-section{background:var(--navy);color:#fff;padding:68px 0}.dark-section p,.dark-section span{color:#a9c3d4}.formula-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-top:25px}.formula-grid>div{padding:20px;border:1px solid #ffffff1c;border-radius:14px;background:#ffffff08}.formula-grid b{display:block;font:600 19px "Space Grotesk";margin-bottom:5px}.formula-grid span{font-size:12px}footer{padding:30px 0;border-top:1px solid var(--line);font-size:12px;color:var(--muted);background:#fff}
.graph-card{background:#fff;border:1px solid var(--line);border-radius:20px;padding:26px;box-shadow:0 12px 38px #1d58710a}.function-row{display:grid;grid-template-columns:1fr auto;gap:12px}.function-input{border:1px solid #cfe1ec;border-radius:10px;padding:14px;font:600 17px "Space Grotesk";color:var(--ink);width:100%}.hint{font-size:12px;color:var(--muted);margin-top:9px}
@media(max-width:800px){.formula-grid{grid-template-columns:1fr 1fr}.cards{grid-template-columns:1fr}}
@media(max-width:600px){.container{width:min(calc(100% - 28px),var(--max))}.nav{height:66px}.nav nav{display:none}.hero{padding:52px 0}.hero.small{padding:34px 0}.app{padding:28px 0 50px}.section-head{display:block}.section-head>p{text-align:left;margin-top:10px}.two,.four{grid-template-columns:1fr}.calculator{padding:18px}.fraction-inputs{gap:10px}.fracbox input,.fracbox hr{width:78px}.operator{font-size:25px}.formula-grid{grid-template-columns:1fr}}
body.dark{--bg:#0d1821;--surface:#142431;--ink:#eff8fd;--muted:#9eb4c3;--line:#274252;background:var(--bg)}body.dark header,body.dark footer,body.dark .card,body.dark .calculator,body.dark .graph-card,body.dark .tab{background:var(--surface)}body.dark .hero{background:#10202b}body.dark .field-label input,body.dark .function-input{background:#142431;color:#eff8fd;border-color:#365466}body.dark .answer{background:#19303f}body.dark .theme-btn{background:var(--surface);color:#fff}

@media(max-width:600px){.function-row{grid-template-columns:1fr}.function-row .primary-btn{width:100%!important;padding:13px!important}.graph-wrap{padding:10px}}


/* SEO content */
.seo-text{padding:64px 0}.seo-text .container{max-width:900px}.seo-text h2{margin:0 0 18px}.seo-text h3{margin:28px 0 8px}.seo-text p{max-width:780px;line-height:1.75;color:#5e7485}.dark .seo-text p{color:#b7c7d2}

/* main-calculator-spacing: consistent gap between arrow and label */
.main-calculator,
.main-calculator-link,
.calculator-main-link,
.card-main-link {
  gap: 8px;
}
.main-calculator svg,
.main-calculator-link svg,
.calculator-main-link svg,
.card-main-link svg {
  margin-right: 6px;
}

/* nav-spacing-final: clear separation between home link and section name */
.nav-back,
.back-link,
.breadcrumb,
.page-nav,
.section-nav {
  gap: 12px;
}
.nav-back > *,
.back-link > *,
.breadcrumb > *,
.page-nav > *,
.section-nav > * {
  margin-right: 0;
}

/* calculator-nav-gap-final */
header a[href*="index.html"] + span,
header a[href*="../index.html"] + span,
.page-header a + span,
.back-row a + span {
  margin-left: 12px;
}

/* calculator-back-eyebrow-final */
.hero.small .back + .eyebrow {
  display: inline-block;
  margin-left: 12px;
}


.related-calculators {
  margin: 32px 0 8px;
}

.related-calculators ul {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  padding-left: 20px;
  margin: 0;
}

.related-calculators li {
  margin: 0;
  padding: 0;
}

.related-calculators li::marker {
  font-size: 0.85em;
}

.related-calculators a {
  display: inline-block;
}