/* calcool.us — premium calculator hub stylesheet */
:root{
  --bg:#0b1120;
  --bg-soft:#0f1729;
  --surface:#ffffff;
  --surface-2:#f7f9fc;
  --ink:#0f1b2d;
  --ink-soft:#475569;
  --line:#e4e9f2;
  --brand:#3b6ff6;
  --brand-2:#7c5cff;
  --brand-ink:#1d4ed8;
  --accent:#0fb9a6;
  --accent-warm:#f7913d;
  --danger:#e0405a;
  --ok:#16a34a;
  --ring:rgba(59,111,246,.28);
  --shadow:0 18px 40px -22px rgba(15,27,45,.45);
  --shadow-sm:0 6px 18px -12px rgba(15,27,45,.55);
  --radius:18px;
  --radius-sm:12px;
  --maxw:1120px;
  --font:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;font-family:var(--font);color:var(--ink);background:var(--surface-2);
  line-height:1.65;font-size:17px;-webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block}
a{color:var(--brand-ink);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 20px}

/* ---------- Header ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(11,17,32,.92);backdrop-filter:blur(10px);
  border-bottom:1px solid rgba(255,255,255,.08);
}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;height:64px;gap:18px}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.24rem;color:#fff;letter-spacing:-.02em}
.logo:hover{text-decoration:none}
.logo .mark{
  width:32px;height:32px;border-radius:9px;display:grid;place-items:center;
  background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff;font-weight:800;font-size:1rem;
  box-shadow:0 8px 18px -8px var(--brand-2);
}
.logo .mark span{transform:translateY(-1px)}
.nav{display:flex;align-items:center;gap:22px}
.nav a{color:#c7d2e6;font-weight:600;font-size:.95rem}
.nav a:hover{color:#fff;text-decoration:none}
.nav-toggle{display:none;background:none;border:0;color:#fff;font-size:1.5rem;cursor:pointer}

/* ---------- Hero ---------- */
.hero{
  background:radial-gradient(1200px 500px at 15% -10%,rgba(124,92,255,.32),transparent 60%),
             radial-gradient(900px 500px at 95% 0%,rgba(15,185,166,.22),transparent 55%),
             linear-gradient(180deg,var(--bg),var(--bg-soft));
  color:#fff;padding:72px 0 60px;position:relative;overflow:hidden;
}
.hero h1{font-size:clamp(2.1rem,5vw,3.3rem);line-height:1.08;margin:0 0 14px;letter-spacing:-.03em;font-weight:800}
.hero p.lede{font-size:1.16rem;color:#c7d2e6;max-width:640px;margin:0 0 26px}
.hero .pill{display:inline-flex;align-items:center;gap:8px;background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.16);
  color:#dbe4f3;font-size:.82rem;font-weight:600;padding:6px 14px;border-radius:999px;margin-bottom:20px}
.hero .pill .dot{width:8px;height:8px;border-radius:50%;background:var(--accent);box-shadow:0 0 0 4px rgba(15,185,166,.25)}

/* search box on home hero */
.hero-search{margin-top:6px;max-width:520px;position:relative}
.hero-search input{
  width:100%;padding:16px 18px 16px 48px;border-radius:14px;border:1px solid rgba(255,255,255,.18);
  background:rgba(255,255,255,.06);color:#fff;font-size:1rem;outline:none;
}
.hero-search input::placeholder{color:#9fb0cc}
.hero-search input:focus{border-color:var(--accent);box-shadow:0 0 0 4px rgba(15,185,166,.18)}
.hero-search svg{position:absolute;left:16px;top:50%;transform:translateY(-50%);opacity:.7}

/* ---------- Breadcrumb ---------- */
.crumbs{font-size:.84rem;color:var(--ink-soft);padding:16px 0 4px}
.crumbs a{color:var(--ink-soft)}
.crumbs a:hover{color:var(--brand-ink)}
.crumbs span[aria-current]{color:var(--ink);font-weight:600}

/* ---------- Layout ---------- */
.layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:34px;padding:34px 0 64px;align-items:start}
@media(max-width:900px){.layout{grid-template-columns:1fr}}
.aside{position:sticky;top:84px;display:flex;flex-direction:column;gap:18px}
@media(max-width:900px){.aside{position:static}}

/* ---------- Calculator card ---------- */
.calc-card{
  background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);padding:28px;margin-bottom:30px;
}
.calc-card h1{font-size:clamp(1.7rem,4vw,2.4rem);margin:0 0 8px;letter-spacing:-.02em;line-height:1.12}
.calc-sub{color:var(--ink-soft);margin:0 0 22px;font-size:1.04rem}
.field{margin-bottom:16px}
.field label{display:block;font-weight:600;font-size:.92rem;margin-bottom:6px;color:var(--ink)}
.field .hint{font-weight:400;color:var(--ink-soft);font-size:.82rem}
.input-wrap{position:relative;display:flex;align-items:center}
.input-wrap .prefix,.input-wrap .suffix{position:absolute;color:var(--ink-soft);font-weight:600;font-size:.95rem}
.input-wrap .prefix{left:14px}
.input-wrap .suffix{right:14px}
.input-wrap.has-prefix input{padding-left:30px}
.input-wrap.has-suffix input{padding-right:42px}
input[type=number],input[type=text],select{
  width:100%;padding:12px 14px;border:1px solid var(--line);border-radius:var(--radius-sm);
  font-size:1.02rem;font-family:var(--font);color:var(--ink);background:#fff;transition:border-color .15s,box-shadow .15s;
}
input:focus,select:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 4px var(--ring)}
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.grid-3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:14px}
@media(max-width:560px){.grid-2,.grid-3{grid-template-columns:1fr}}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;cursor:pointer;
  background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff;border:0;
  padding:13px 24px;border-radius:12px;font-weight:700;font-size:1rem;font-family:var(--font);
  box-shadow:0 12px 24px -12px var(--brand-2);transition:transform .08s,box-shadow .2s;width:100%;
}
.btn:hover{transform:translateY(-1px);box-shadow:0 16px 28px -12px var(--brand-2)}
.btn:active{transform:translateY(0)}
.btn.secondary{background:#fff;color:var(--brand-ink);border:1px solid var(--line);box-shadow:none}
.btn-row{display:flex;gap:12px;margin-top:8px}
.radio-row{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:8px}
.radio-row label{
  flex:1;min-width:120px;border:1px solid var(--line);border-radius:10px;padding:10px 12px;cursor:pointer;
  font-size:.92rem;font-weight:600;text-align:center;transition:all .15s;color:var(--ink-soft);background:var(--surface-2);
}
.radio-row input{position:absolute;opacity:0}
.radio-row input:checked + span,.radio-row label.active{color:var(--brand-ink)}
.radio-row label:has(input:checked){border-color:var(--brand);background:#eef3ff;color:var(--brand-ink)}

/* ---------- Result ---------- */
.result{
  margin-top:22px;border-radius:14px;padding:22px;
  background:linear-gradient(135deg,#0f1729,#16223d);color:#fff;
  border:1px solid rgba(255,255,255,.08);
}
.result.empty{background:var(--surface-2);color:var(--ink-soft);border:1px dashed var(--line);text-align:center}
.result .big{font-size:clamp(2rem,6vw,2.8rem);font-weight:800;letter-spacing:-.02em;line-height:1.1;font-family:var(--mono)}
.result .label{font-size:.82rem;text-transform:uppercase;letter-spacing:.08em;color:#9fb0cc;margin-bottom:4px;font-weight:700}
.result .accent{color:#5ee0cf}
.result-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:14px;margin-top:16px}
.result-grid .cell{background:rgba(255,255,255,.06);border-radius:10px;padding:12px 14px}
.result-grid .cell .label{margin-bottom:2px}
.result-grid .cell .v{font-size:1.25rem;font-weight:700;font-family:var(--mono)}
.disclaimer{
  margin-top:16px;background:#fff6ed;border:1px solid #fcd9b0;border-radius:10px;padding:12px 14px;
  font-size:.86rem;color:#92531a;
}
.disclaimer strong{color:#7a3e0a}

/* ---------- Content prose ---------- */
.prose{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:30px;box-shadow:var(--shadow-sm);margin-bottom:26px}
.prose h2{font-size:1.5rem;margin:6px 0 12px;letter-spacing:-.01em;scroll-margin-top:84px}
.prose h3{font-size:1.18rem;margin:24px 0 8px}
.prose p{margin:0 0 14px;color:#2b3a52}
.prose ul,.prose ol{margin:0 0 16px;padding-left:22px;color:#2b3a52}
.prose li{margin-bottom:7px}
.prose strong{color:var(--ink)}
.formula{
  background:#0f1729;color:#e8eefb;border-radius:12px;padding:18px 20px;font-family:var(--mono);
  font-size:1.02rem;overflow-x:auto;margin:8px 0 18px;border:1px solid rgba(255,255,255,.06);
}
.formula .var{color:#5ee0cf}
.formula .op{color:#f7913d}
.example-box{background:var(--surface-2);border-left:4px solid var(--brand);border-radius:0 12px 12px 0;padding:16px 20px;margin:16px 0}
.example-box .step{margin-bottom:6px}
table.data{width:100%;border-collapse:collapse;margin:8px 0 18px;font-size:.94rem}
table.data th,table.data td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--line)}
table.data th{background:var(--surface-2);font-weight:700;color:var(--ink)}
table.data tr:hover td{background:#fafbfe}
.callout{background:#eef3ff;border:1px solid #d3e0ff;border-radius:12px;padding:16px 18px;margin:16px 0;font-size:.95rem;color:#1e3a8a}

/* ---------- FAQ ---------- */
.faq details{border:1px solid var(--line);border-radius:12px;margin-bottom:10px;background:var(--surface);overflow:hidden}
.faq summary{cursor:pointer;padding:16px 18px;font-weight:700;font-size:1.02rem;list-style:none;display:flex;justify-content:space-between;align-items:center;gap:12px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-size:1.4rem;color:var(--brand);font-weight:400;line-height:1}
.faq details[open] summary::after{content:"−"}
.faq details[open] summary{border-bottom:1px solid var(--line)}
.faq .answer{padding:14px 18px;color:#2b3a52}
.faq .answer p{margin:0 0 10px}

/* ---------- Sidebar widgets ---------- */
.widget{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow-sm)}
.widget h3{margin:0 0 12px;font-size:1.02rem;letter-spacing:-.01em}
.widget ul{list-style:none;margin:0;padding:0}
.widget li{margin-bottom:2px}
.widget li a{display:flex;align-items:center;gap:8px;padding:8px 10px;border-radius:9px;color:var(--ink-soft);font-size:.94rem;font-weight:600}
.widget li a:hover{background:var(--surface-2);color:var(--brand-ink);text-decoration:none}
.widget .ico{width:18px;text-align:center}
.ad-slot{background:var(--surface-2);border:1px dashed var(--line);border-radius:12px;min-height:250px;display:grid;place-items:center;color:#aab6c8;font-size:.8rem;text-align:center}

/* ---------- Directory grid (home) ---------- */
.section-head{text-align:center;max-width:640px;margin:54px auto 28px}
.section-head h2{font-size:clamp(1.6rem,4vw,2.1rem);margin:0 0 8px;letter-spacing:-.02em}
.section-head p{color:var(--ink-soft);margin:0}
.cat-label{display:flex;align-items:center;gap:10px;margin:38px 0 16px;font-weight:800;font-size:1.05rem;color:var(--ink);text-transform:uppercase;letter-spacing:.04em;font-size:.92rem}
.cat-label::after{content:"";flex:1;height:1px;background:var(--line)}
.cat-label .emoji{font-size:1.2rem}
.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(248px,1fr));gap:18px}
.calc-tile{
  background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:20px;display:block;
  box-shadow:var(--shadow-sm);transition:transform .14s,box-shadow .2s,border-color .2s;position:relative;overflow:hidden;
}
.calc-tile:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:#cdd9f0;text-decoration:none}
.calc-tile .ti{width:42px;height:42px;border-radius:11px;display:grid;place-items:center;font-size:1.3rem;margin-bottom:12px;
  background:linear-gradient(135deg,#eef3ff,#e7f6f3)}
.calc-tile h3{margin:0 0 4px;font-size:1.08rem;color:var(--ink);letter-spacing:-.01em}
.calc-tile p{margin:0;font-size:.9rem;color:var(--ink-soft);line-height:1.5}
.calc-tile .badge{position:absolute;top:14px;right:14px;font-size:.66rem;font-weight:800;text-transform:uppercase;letter-spacing:.05em;
  color:#fff;background:linear-gradient(135deg,var(--accent-warm),#e0405a);padding:3px 8px;border-radius:999px}

/* ---------- Author / trust ---------- */
.author-box{display:flex;gap:16px;align-items:flex-start;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow-sm);margin-bottom:26px}
.author-box .avatar{width:56px;height:56px;border-radius:50%;flex:none;background:linear-gradient(135deg,var(--brand),var(--brand-2));display:grid;place-items:center;color:#fff;font-weight:800;font-size:1.3rem}
.author-box .meta{font-size:.92rem;color:var(--ink-soft)}
.author-box .meta strong{color:var(--ink);font-size:1rem}
.author-box .meta .role{color:var(--brand-ink);font-weight:600;font-size:.85rem}
.sources{font-size:.88rem;color:var(--ink-soft)}
.sources a{font-weight:600}
.toc{font-size:.92rem}
.toc a{display:block;padding:6px 10px;border-radius:8px;color:var(--ink-soft);font-weight:600}
.toc a:hover{background:var(--surface-2);color:var(--brand-ink);text-decoration:none}

/* ---------- Footer ---------- */
.site-footer{background:var(--bg);color:#9fb0cc;padding:48px 0 28px;margin-top:30px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:30px}
@media(max-width:760px){.footer-grid{grid-template-columns:1fr 1fr}}
.site-footer h4{color:#fff;font-size:.96rem;margin:0 0 12px;letter-spacing:-.01em}
.site-footer ul{list-style:none;margin:0;padding:0}
.site-footer li{margin-bottom:8px}
.site-footer a{color:#9fb0cc;font-size:.92rem}
.site-footer a:hover{color:#fff}
.site-footer .brand-blurb{font-size:.92rem;line-height:1.6;max-width:280px}
.footer-bottom{border-top:1px solid rgba(255,255,255,.08);margin-top:34px;padding-top:20px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;font-size:.84rem}

/* ---------- Utility ---------- */
.muted{color:var(--ink-soft)}
.center{text-align:center}
.mt0{margin-top:0}
.tag{display:inline-block;background:#eef3ff;color:var(--brand-ink);font-size:.74rem;font-weight:700;padding:3px 9px;border-radius:999px;margin-right:6px}
.related-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:12px;margin-top:8px}
.related-grid a{display:flex;align-items:center;gap:9px;padding:12px 14px;border:1px solid var(--line);border-radius:11px;background:var(--surface);font-weight:600;color:var(--ink);font-size:.92rem}
.related-grid a:hover{border-color:#cdd9f0;background:var(--surface-2);text-decoration:none}

/* mobile nav */
@media(max-width:680px){
  .nav{position:fixed;inset:64px 0 auto 0;flex-direction:column;background:var(--bg-soft);padding:16px 20px;gap:6px;
    border-bottom:1px solid rgba(255,255,255,.08);display:none}
  .nav.open{display:flex}
  .nav a{padding:10px 4px;width:100%;border-bottom:1px solid rgba(255,255,255,.06)}
  .nav-toggle{display:block}
  body{font-size:16px}
  .calc-card,.prose{padding:22px 18px}
}