/* ============================================================
   VoltConvert — "Blueprint Instrument" design system
   Fraunces (display) · IBM Plex Sans (body) · IBM Plex Mono (data)
   ============================================================ */
:root{
  --bg:#0b0e14; --bg-2:#0f131c; --panel:#141a24; --panel-2:#1a212e;
  --line:#26303f; --line-bright:#33405380;
  --ink:#eef2f7; --ink-2:#aeb9c7; --ink-3:#6f7d8e;
  --amber:#ffb627; --amber-deep:#e89200; --cyan:#39c5ff;
  --good:#46d18a; --bad:#ff6b6b;
  --r:14px; --r-lg:20px; --maxw:920px; --grid:rgba(57,197,255,.045);
  --display:"Fraunces",Georgia,serif;
  --body:"IBM Plex Sans",-apple-system,system-ui,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,Menlo,monospace;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:var(--body);color:var(--ink);line-height:1.65;background-color:var(--bg);
  background-image:
    linear-gradient(var(--grid) 1px,transparent 1px),
    linear-gradient(90deg,var(--grid) 1px,transparent 1px),
    radial-gradient(1100px 560px at 82% -8%, rgba(57,197,255,.07), transparent 60%),
    radial-gradient(820px 460px at -8% 4%, rgba(255,182,39,.06), transparent 55%);
  background-size:34px 34px,34px 34px,100% 100%,100% 100%;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;min-height:100vh;
}
a{color:var(--cyan);text-decoration:none}
a:hover{color:var(--amber)}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 22px}
::selection{background:var(--amber);color:#1a1200}

header.site{position:sticky;top:0;z-index:60;border-bottom:1px solid var(--line);background:rgba(11,14,20,.82);backdrop-filter:blur(12px) saturate(140%)}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;height:62px}
.brand{display:flex;align-items:center;gap:10px;font-family:var(--display);font-weight:600;font-size:1.3rem;letter-spacing:-.01em;color:var(--ink);font-optical-sizing:auto}
.brand:hover{color:var(--ink)}
.brand .bolt{display:inline-grid;place-items:center;width:30px;height:30px;border-radius:8px;background:linear-gradient(150deg,var(--amber),var(--amber-deep));color:#1a1200;box-shadow:0 0 0 1px rgba(255,182,39,.3),0 6px 18px -6px rgba(255,182,39,.6)}
.brand .bolt svg{width:17px;height:17px}
nav.top{display:flex;gap:6px}
nav.top a{color:var(--ink-2);font-size:.9rem;padding:7px 12px;border-radius:8px;transition:.18s}
nav.top a:hover{color:var(--ink);background:var(--panel-2);text-decoration:none}

.hero{padding-top:74px;padding-bottom:46px;position:relative}
.eyebrow{font-family:var(--mono);font-size:.74rem;letter-spacing:.22em;text-transform:uppercase;color:var(--amber);margin-bottom:18px;display:flex;align-items:center;gap:10px}
.eyebrow::before{content:"";width:26px;height:1px;background:var(--amber)}
.hero h1{font-family:var(--display);font-optical-sizing:auto;font-weight:600;font-size:clamp(2.3rem,6vw,3.7rem);line-height:1.02;letter-spacing:-.025em;max-width:14ch}
.hero h1 em{font-style:italic;color:var(--amber)}
.hero p.sub{color:var(--ink-2);font-size:1.13rem;max-width:52ch;margin-top:20px}

.reveal{opacity:0;transform:translateY(14px);animation:rise .7s cubic-bezier(.2,.7,.2,1) forwards}
.reveal:nth-child(2){animation-delay:.07s}
.reveal:nth-child(3){animation-delay:.14s}
.reveal:nth-child(4){animation-delay:.21s}
@keyframes rise{to{opacity:1;transform:none}}
@media(prefers-reduced-motion:reduce){.reveal{animation:none;opacity:1;transform:none}}

.searchbar{margin-top:30px;max-width:480px;position:relative}
.searchbar svg{position:absolute;left:16px;top:50%;transform:translateY(-50%);width:18px;height:18px;color:var(--ink-3)}
.searchbar input{width:100%;padding:15px 16px 15px 44px;border-radius:var(--r);border:1px solid var(--line);background:var(--panel);color:var(--ink);font-size:1rem;font-family:var(--body);transition:.18s}
.searchbar input::placeholder{color:var(--ink-3)}
.searchbar input:focus{outline:none;border-color:var(--cyan);box-shadow:0 0 0 3px rgba(57,197,255,.16)}
.searchhint{margin-top:10px;font-family:var(--mono);font-size:.74rem;color:var(--ink-3)}

.section-head{margin:56px 0 22px;display:flex;align-items:baseline;gap:14px}
.section-head h2{font-family:var(--display);font-optical-sizing:auto;font-weight:600;font-size:1.6rem;letter-spacing:-.02em}
.section-head .rule{flex:1;height:1px;background:linear-gradient(90deg,var(--line),transparent)}
.section-sub{color:var(--ink-2);margin:-8px 0 24px}

.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(218px,1fr));gap:13px}
.card{position:relative;display:block;padding:18px;border:1px solid var(--line);border-radius:var(--r);background:linear-gradient(180deg,var(--panel),var(--bg-2));overflow:hidden;transition:transform .16s ease,border-color .16s ease}
.card::after{content:"";position:absolute;inset:0;border-radius:var(--r);padding:1px;background:linear-gradient(140deg,transparent 40%,rgba(255,182,39,0));transition:.16s;pointer-events:none}
.card:hover{transform:translateY(-3px);border-color:var(--amber);text-decoration:none}
.card:hover::after{background:linear-gradient(140deg,transparent 30%,rgba(255,182,39,.35))}
.card .pair{font-family:var(--display);font-weight:600;font-size:1.12rem;color:var(--ink);letter-spacing:-.01em}
.card .pair .arr{color:var(--amber);font-style:normal}
.card .desc{color:var(--ink-3);font-size:.85rem;margin-top:5px;font-family:var(--body)}
.card .vol{display:inline-block;margin-top:12px;font-family:var(--mono);font-size:.7rem;color:var(--amber);border:1px solid var(--line-bright);padding:2px 9px;border-radius:30px}

.crumb{font-family:var(--mono);font-size:.78rem;color:var(--ink-3);padding:22px 0 0}
.crumb a{color:var(--ink-3)}
.crumb a:hover{color:var(--amber)}
.crumb span{color:var(--ink-2)}

.tool{position:relative;margin:18px 0 30px;padding:30px;border:1px solid var(--line);border-radius:var(--r-lg);background:radial-gradient(600px 200px at 100% 0,rgba(57,197,255,.06),transparent 60%),linear-gradient(180deg,var(--panel),var(--bg-2))}
.tool::before{content:"CALC";position:absolute;top:16px;right:20px;font-family:var(--mono);font-size:.66rem;letter-spacing:.2em;color:var(--ink-3);opacity:.6}
.tool h1{font-family:var(--display);font-optical-sizing:auto;font-weight:600;font-size:clamp(1.6rem,4vw,2.15rem);letter-spacing:-.022em;max-width:18ch}
.tool .lead{color:var(--ink-2);margin-top:8px;margin-bottom:24px;max-width:54ch}
.convert-row{display:grid;grid-template-columns:1fr auto 1fr;gap:14px;align-items:end}
@media(max-width:560px){.convert-row{grid-template-columns:1fr}.swap{justify-self:start;transform:rotate(90deg)}}
.field label{display:block;font-family:var(--mono);font-size:.72rem;color:var(--ink-3);margin-bottom:7px;text-transform:uppercase;letter-spacing:.08em}
.field input,.field select{width:100%;padding:14px;border-radius:11px;border:1px solid var(--line);background:var(--bg);color:var(--ink);font-size:1.18rem;font-family:var(--mono);transition:.16s}
.field input:focus,.field select:focus{outline:none;border-color:var(--cyan);box-shadow:0 0 0 3px rgba(57,197,255,.14)}
.field select{cursor:pointer}
.swap{font-family:var(--mono);font-size:1.2rem;color:var(--amber);padding-bottom:13px;text-align:center;user-select:none}
.result{margin-top:24px;padding:22px;border-radius:13px;background:linear-gradient(180deg,var(--panel-2),var(--bg));border:1px solid var(--line-bright);position:relative;overflow:hidden}
.result::before{content:"";position:absolute;left:0;top:0;bottom:0;width:3px;background:linear-gradient(180deg,var(--amber),var(--amber-deep))}
.result .reslabel{font-family:var(--mono);font-size:.68rem;letter-spacing:.18em;text-transform:uppercase;color:var(--ink-3);margin-bottom:6px}
.result .big{font-family:var(--mono);font-weight:500;font-size:2rem;color:var(--amber);line-height:1.1;word-break:break-word}
.result .formula{color:var(--ink-2);font-size:.9rem;margin-top:10px;font-family:var(--mono);line-height:1.5}

.content{margin:34px 0}
.content h2{font-family:var(--display);font-optical-sizing:auto;font-weight:600;font-size:1.42rem;letter-spacing:-.02em;margin:30px 0 11px}
.content h3{font-family:var(--display);font-weight:600;font-size:1.1rem;margin:22px 0 8px;color:var(--ink)}
.content p{margin-bottom:14px;color:var(--ink-2)}
.content ul{margin:0 0 14px 20px;color:var(--ink-2)}
.content li{margin-bottom:6px}
.content strong{color:var(--ink)}
table.ref{width:100%;border-collapse:collapse;margin:16px 0;font-size:.92rem;border:1px solid var(--line);border-radius:10px;overflow:hidden}
table.ref th,table.ref td{border-bottom:1px solid var(--line);padding:10px 13px;text-align:left}
table.ref tr:last-child td{border-bottom:none}
table.ref th{background:var(--panel-2);font-family:var(--mono);font-size:.74rem;color:var(--ink-3);text-transform:uppercase;letter-spacing:.05em;font-weight:500}
table.ref td{font-family:var(--mono);color:var(--ink-2)}
table.ref tr:hover td{background:rgba(57,197,255,.03)}

.faq details{border:1px solid var(--line);border-radius:11px;padding:0 17px;margin-bottom:10px;background:var(--panel);transition:.16s}
.faq details[open]{border-color:var(--line-bright)}
.faq summary{cursor:pointer;padding:15px 0;font-weight:600;font-family:var(--body);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-family:var(--mono);color:var(--amber);font-size:1.3rem;transition:.2s}
.faq details[open] summary::after{transform:rotate(45deg)}
.faq details p{padding:0 0 15px;color:var(--ink-2);margin:0}

/* Ad slots hidden until real AdSense code exists.
   To activate later: change display:none to display:block and paste
   your AdSense snippet inside each .ad-slot div. */
.ad-slot{display:none}

footer.site{border-top:1px solid var(--line);margin-top:64px;padding:38px 0;color:var(--ink-3);font-size:.88rem;background:var(--bg-2)}
footer.site .wrap{display:flex;flex-wrap:wrap;gap:18px;justify-content:space-between;align-items:center}
footer.site .fbrand{font-family:var(--display);color:var(--ink-2);font-weight:600}
footer.site a{color:var(--ink-3)}
footer.site a:hover{color:var(--amber)}
.backlink{font-family:var(--mono);font-size:.85rem}

/* --- mobile refinements --- */
@media(max-width:620px){
  table.ref{display:block;overflow-x:auto;-webkit-overflow-scrolling:touch;white-space:nowrap}
  .tool{padding:22px 18px}
  .hero{padding-top:52px;padding-bottom:36px}
}


/* --- hero v2: two-column with quick-convert card --- */
.hero-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:48px;align-items:center}
.quicklinks{margin-top:18px;display:flex;flex-wrap:wrap;gap:8px}
.quicklinks a{font-family:var(--mono);font-size:.78rem;color:var(--ink-2);border:1px solid var(--line);background:var(--panel);padding:7px 13px;border-radius:30px;text-decoration:none;transition:.16s}
.quicklinks a:hover{color:var(--amber);border-color:var(--amber)}
.hero-card{border:1px solid var(--line);border-radius:var(--r-lg);padding:24px;background:radial-gradient(420px 180px at 100% 0,rgba(57,197,255,.07),transparent 60%),linear-gradient(180deg,var(--panel),var(--bg-2));box-shadow:0 24px 60px -30px rgba(0,0,0,.7)}
.hero-card .hc-title{font-family:var(--mono);font-size:.7rem;letter-spacing:.18em;text-transform:uppercase;color:var(--ink-3);margin-bottom:16px}
.hero-card .hc-title span{color:var(--amber)}
.hc-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.hc-result{margin-top:16px;padding:16px;border-radius:12px;background:var(--bg);border:1px solid var(--line-bright);display:flex;align-items:baseline;justify-content:space-between;gap:10px}
.hc-result .hc-label{font-family:var(--mono);font-size:.68rem;letter-spacing:.16em;text-transform:uppercase;color:var(--ink-3)}
.hc-result .hc-big{font-family:var(--mono);font-size:1.7rem;color:var(--amber);font-weight:500}
.hc-link{display:inline-block;margin-top:14px;font-family:var(--mono);font-size:.8rem}
@media(max-width:860px){.hero-grid{grid-template-columns:1fr;gap:30px}}

/* --- mobile header & hero compaction --- */
@media(max-width:520px){
  .brand{font-size:1.08rem}
  .brand .bolt{width:26px;height:26px}
  .brand .bolt svg{width:15px;height:15px}
  nav.top{gap:2px}
  nav.top a{padding:6px 8px;font-size:.8rem}
  .hero{padding-top:40px;padding-bottom:28px}
  .hero h1{font-size:clamp(1.9rem,8vw,2.6rem)}
  .hero p.sub{font-size:1rem}
  .hc-result .hc-big{font-size:1.4rem}
}


/* --- authority build: author box, social footer, article tweaks --- */
.authorbox{margin-top:34px;padding:18px 20px;border:1px solid var(--line);border-radius:12px;background:var(--panel);font-size:.88rem;color:var(--ink-2);display:flex;flex-direction:column;gap:8px}
.authorbox .ab-date{font-family:var(--mono);font-size:.72rem;color:var(--ink-3);letter-spacing:.06em;text-transform:uppercase}
.social-foot a{color:var(--ink-3)}
.social-foot a:hover{color:var(--amber)}
article.content h2{margin-top:34px}
article.content p{font-size:1.02rem;line-height:1.75}