:root{
  --ink:#16202b;
  --paper:#f7f5ef;
  --line:#16202b;
  --blue:#1f4d7a;
  --orange:#e8562f;
  --muted:#6b7580;
  --card:#ffffff;
  --border:#dcd7ca;
}
*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  font-family:'Segoe UI',-apple-system,Helvetica,Arial,sans-serif;
  background:var(--paper);
  color:var(--ink);
  -webkit-font-smoothing:antialiased;
  line-height:1.5;
}
a{color:var(--blue);}
img{max-width:100%;}
.wrap{max-width:960px;margin:0 auto;padding:0 20px;}
.narrow{max-width:720px;margin:0 auto;padding:0 20px;}

/* Nav */
.site-nav{border-bottom:1px solid var(--border);background:var(--card);position:sticky;top:0;z-index:50;}
.site-nav .inner{max-width:1080px;margin:0 auto;padding:14px 20px;display:flex;align-items:center;justify-content:space-between;gap:20px;}
.brand{font-size:19px;font-weight:700;text-decoration:none;color:var(--ink);}
.brand span{color:var(--orange);}
.nav-links{display:flex;gap:20px;list-style:none;margin:0;padding:0;flex-wrap:wrap;}
.nav-links a{color:var(--ink);text-decoration:none;font-size:14px;font-weight:500;}
.nav-links a:hover{color:var(--blue);}
.nav-toggle{display:none;background:none;border:1px solid var(--border);border-radius:6px;padding:6px 10px;font-size:16px;cursor:pointer;}
@media (max-width:720px){
  .nav-links{display:none;width:100%;flex-direction:column;gap:12px;padding-top:12px;}
  .nav-links.open{display:flex;}
  .nav-toggle{display:block;}
  .site-nav .inner{flex-wrap:wrap;}
}

/* Hero */
.hero{padding:52px 0 30px;}
.hero h1{font-size:clamp(28px,4vw,42px);margin:0 0 12px;letter-spacing:-.3px;}
.hero p{color:var(--muted);font-size:16px;max-width:560px;margin:0 0 6px;}
.hero .accent{color:var(--orange);}

/* Tool grid */
.tool-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:30px 0 50px;}
@media (max-width:760px){.tool-grid{grid-template-columns:1fr 1fr;}}
@media (max-width:520px){.tool-grid{grid-template-columns:1fr;}}
.tool-card{
  background:var(--card);border:1px solid var(--border);border-radius:12px;padding:20px;
  text-decoration:none;color:var(--ink);transition:transform .12s ease, box-shadow .12s ease;
  display:flex;flex-direction:column;gap:6px;
}
.tool-card:hover{transform:translateY(-3px);box-shadow:0 8px 20px rgba(22,32,43,.08);}
.tool-card .icon{font-size:26px;}
.tool-card h3{margin:2px 0 0;font-size:16px;}
.tool-card p{margin:0;font-size:13px;color:var(--muted);}

/* Sections */
section{margin:44px 0;}
h2{font-size:24px;margin:0 0 14px;}
h3{font-size:18px;}
.lede{color:var(--muted);font-size:15px;max-width:640px;}

/* Cards / panels */
.panel{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:20px 18px;}
.btn{border:none;border-radius:7px;padding:10px 16px;font-size:13px;cursor:pointer;font-weight:600;}
.btn.primary{background:var(--ink);color:var(--paper);}
.btn.ghost{background:transparent;color:var(--muted);border:1px solid var(--border);}

/* Converter widget */
.converter{display:flex;flex-wrap:wrap;gap:14px;align-items:center;margin:18px 0;}
.converter .field{display:flex;flex-direction:column;gap:6px;}
.converter label{font-size:12px;color:var(--muted);text-transform:uppercase;letter-spacing:.5px;}
.converter input[type=number]{padding:10px 12px;border:1px solid var(--border);border-radius:8px;font-size:16px;width:150px;}
.converter select{padding:10px 12px;border:1px solid var(--border);border-radius:8px;font-size:15px;}
.converter .equals{font-size:20px;color:var(--muted);padding-top:18px;}
.result{font-size:28px;font-weight:700;margin-top:4px;}
.result span{color:var(--orange);}
.swap-btn{border:1px solid var(--border);background:var(--card);border-radius:50%;width:38px;height:38px;cursor:pointer;font-size:15px;margin-top:16px;}

/* Ruler widget (shared with tool page) */
.ruler-panel{margin-top:10px;}
.ruler-track{position:relative;height:96px;overflow-x:auto;overflow-y:hidden;border-top:2px solid var(--line);-webkit-overflow-scrolling:touch;}
.ruler-track::-webkit-scrollbar{height:6px;}
.ruler-inner{position:relative;height:100%;}
.tick-major{position:absolute;top:0;width:1px;background:var(--line);height:34px;}
.tick-mid{position:absolute;top:0;width:1px;background:var(--muted);height:22px;}
.tick-minor{position:absolute;top:0;width:1px;background:#c9c2af;height:12px;}
.tick-label{position:absolute;top:38px;font-size:11px;color:var(--muted);transform:translateX(-50%);font-variant-numeric:tabular-nums;}
.hint{display:flex;align-items:center;justify-content:space-between;margin-top:14px;font-size:12.5px;color:var(--muted);flex-wrap:wrap;gap:8px;}
.fixlink{color:var(--blue);text-decoration:underline;cursor:pointer;background:none;border:none;font:inherit;padding:0;}
.fixlink.good{color:#2a7d4f;text-decoration:none;}
.calib{margin-top:16px;background:var(--card);border:1px solid var(--border);border-radius:12px;padding:20px;display:none;}
.calib.open{display:block;}
.card-zone{position:relative;height:150px;background:repeating-linear-gradient(45deg,#eee,#eee 6px,#f7f5ef 6px,#f7f5ef 12px);border-radius:8px;display:flex;align-items:center;justify-content:center;margin-bottom:16px;}
.card-box{position:relative;height:82px;background:var(--blue);border-radius:6px;box-shadow:0 4px 10px rgba(0,0,0,.15);display:flex;align-items:center;justify-content:flex-end;}
.card-box::before{content:"credit card";position:absolute;left:10px;top:10px;color:#fff;font-size:11px;letter-spacing:.5px;opacity:.85;}
.handle{width:22px;height:22px;background:var(--orange);border-radius:50%;position:absolute;right:-11px;top:50%;transform:translateY(-50%);cursor:ew-resize;box-shadow:0 2px 6px rgba(0,0,0,.3);border:3px solid var(--paper);}
.units-toggle{display:inline-flex;background:var(--card);border:1px solid var(--border);border-radius:8px;overflow:hidden;}
.units-toggle button{border:none;background:transparent;padding:7px 14px;font-size:13px;cursor:pointer;color:var(--muted);}
.units-toggle button.active{background:var(--ink);color:var(--paper);}

/* Tables */
table.conv-table{width:100%;border-collapse:collapse;margin:18px 0;font-size:14px;}
table.conv-table th, table.conv-table td{border:1px solid var(--border);padding:8px 10px;text-align:left;}
table.conv-table th{background:#efece3;}

/* FAQ */
.faq-item{border-bottom:1px solid var(--border);padding:14px 0;}
.faq-item h4{margin:0 0 6px;font-size:15px;}
.faq-item p{margin:0;color:var(--muted);font-size:14px;}

/* Blog */
.post-list{display:flex;flex-direction:column;gap:16px;margin:24px 0;}
.post-card{border:1px solid var(--border);border-radius:12px;padding:18px 20px;background:var(--card);text-decoration:none;color:var(--ink);display:block;}
.post-card h3{margin:0 0 6px;}
.post-card p{margin:0;color:var(--muted);font-size:14px;}
article.post{font-size:16px;}
article.post h1{font-size:30px;}
article.post h2{font-size:21px;margin-top:32px;}
article.post p{margin:14px 0;}
.byline{color:var(--muted);font-size:13px;margin-bottom:26px;}

/* Footer */
footer{border-top:1px solid var(--border);margin-top:60px;padding:30px 0;color:var(--muted);font-size:13px;}
footer .inner{max-width:1080px;margin:0 auto;padding:0 20px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;}
footer a{color:var(--muted);margin-right:14px;text-decoration:none;}
footer a:hover{color:var(--blue);}