/* Tool Hub — Apple-style design system */
:root{
  --bg:#f5f5f7;            /* Apple gray */
  --bg2:#ffffff;
  --ink:#1d1d1f;           /* near-black text */
  --muted:#6e6e73;         /* secondary gray */
  --brand:#0071e3;         /* Apple blue */
  --brand-2:#0077ed;
  --line:rgba(0,0,0,.10);
  --card:#ffffff;
  --soft:#fafafc;
  --ok:#1d8352;
  --radius:18px;
  font-size:16px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","SF Pro Text","Helvetica Neue",Helvetica,Arial,sans-serif;
  background:var(--bg);color:var(--ink);line-height:1.65;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
  letter-spacing:-0.011em;
}
a{color:var(--brand);text-decoration:none;transition:color .18s ease}
a:hover{color:var(--brand-2)}
.wrap{max-width:900px;margin:0 auto;padding-left:22px;padding-right:22px}
/* frosted nav */
header.nav{position:sticky;top:0;z-index:50;background:rgba(245,245,247,.72);backdrop-filter:saturate(180%) blur(20px);-webkit-backdrop-filter:saturate(180%) blur(20px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;gap:16px;padding:14px 22px;max-width:900px;margin:0 auto}
.brand{font-weight:700;color:var(--ink);font-size:1.05rem;letter-spacing:-0.02em}
.brand-mark{height:1.3em;width:auto;vertical-align:-0.22em;margin-right:8px}
.nav-links{display:flex;gap:8px;margin-left:auto;flex-wrap:wrap}
.nav-links a{padding:6px 12px;border-radius:980px;color:var(--ink);font-size:.92rem;font-weight:500}
.nav-links a:hover{background:rgba(0,0,0,.05);color:var(--ink);text-decoration:none}
.nav-toggle{display:none}
.nav-burger{display:none;font-size:1.5rem;line-height:1;cursor:pointer;margin-left:auto;padding:4px 10px;border-radius:10px;color:var(--ink)}
.nav-burger:hover{background:rgba(0,0,0,.05)}
main{padding:64px 0 96px}
h1{font-size:clamp(1.9rem,4.2vw,2.7rem);font-weight:700;letter-spacing:-0.03em;line-height:1.1;margin-bottom:14px}
.lead{color:var(--muted);font-size:1.1rem;margin-bottom:30px;max-width:60ch}
.toolcard,.panel{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:28px;margin-bottom:28px;box-shadow:0 4px 20px rgba(0,0,0,.04)}
h2{font-size:1.5rem;font-weight:700;letter-spacing:-0.02em;margin:0 0 .6em}
h3{font-size:1.15rem;font-weight:600;margin:0 0 .5em}
label{display:block;font-weight:600;margin-bottom:8px;font-size:.92rem;color:var(--ink)}
input,select,textarea{width:100%;padding:13px 14px;border:1px solid var(--line);border-radius:12px;font-size:1rem;background:#fff;color:var(--ink);transition:border-color .18s ease,box-shadow .18s ease}
input:focus,select:focus,textarea:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 4px rgba(0,113,227,.12)}
textarea{min-height:160px;resize:vertical;font-family:-apple-system,Menlo,Consolas,monospace;font-size:.92rem}
.field{margin-bottom:18px}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.btn{display:inline-block;background:var(--brand);color:#fff;border:0;border-radius:980px;padding:12px 24px;font-size:1rem;font-weight:600;cursor:pointer;transition:background .18s ease,transform .1s ease}
.btn:hover{background:var(--brand-2)}
.btn:active{transform:scale(.98)}
.btn.ghost{background:rgba(0,0,0,.05);color:var(--ink);border:none}
.btn.ghost:hover{background:rgba(0,0,0,.09);color:var(--ink)}
.btnrow{display:flex;gap:10px;flex-wrap:wrap;margin-top:14px;align-items:center}
.result{background:var(--soft);border:1px solid var(--line);border-radius:14px;padding:20px;margin-top:20px}
.result .big{font-size:2.1rem;font-weight:700;color:var(--brand);letter-spacing:-0.03em}
.result .row{display:flex;justify-content:space-between;padding:8px 0;border-bottom:1px solid var(--line);font-size:.98rem}
.result .row:last-child{border-bottom:0}
.stat{display:inline-block;background:rgba(0,113,227,.10);color:var(--brand);border-radius:980px;padding:5px 14px;font-size:.85rem;font-weight:600}
.note{font-size:.86rem;color:var(--muted);margin-top:12px}
/* hub tool tiles */
ul.tools{list-style:none;display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:20px;margin:0 0 18px}
ul.tools li a{display:block;border:1px solid var(--line);background:var(--card);border-radius:var(--radius);padding:22px;color:var(--ink);transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease}
ul.tools li a:hover{border-color:var(--brand);transform:translateY(-3px);box-shadow:0 12px 30px rgba(0,0,0,.08);text-decoration:none}
ul.tools .tl{font-weight:700;display:block;letter-spacing:-0.01em;margin-bottom:4px}
ul.tools .td{color:var(--muted);font-size:.9rem}
/* table */
table{width:100%;border-collapse:collapse;font-size:.88rem;margin-top:14px}
th,td{border:1px solid var(--line);padding:9px 12px;text-align:left}
th{background:var(--soft);font-weight:600}
.faq h3{margin-top:24px;font-weight:600}
pre.code{background:#0f172a;color:#e2e8f0;padding:16px;border-radius:12px;overflow-x:auto;font-size:.85rem}
footer{border-top:1px solid var(--line);background:var(--bg2);padding:52px 0;color:var(--muted);font-size:.9rem}
footer .inner{max-width:900px;margin:0 auto;padding:0 22px;text-align:center}
footer .inner a{margin:0 6px}
footer .legal{display:inline-block;margin-top:8px}
/* breadcrumb */
.crumb{display:flex;gap:8px;align-items:center;color:var(--muted);font-size:.9rem;margin-bottom:18px}
.crumb a{color:var(--muted)}
.crumb a:hover{color:var(--brand)}
.crumb span{color:var(--ink);font-weight:500}
@media(max-width:640px){
  .nav-inner{position:relative;flex-wrap:wrap}
  .nav-burger{display:block}
  .nav-links{display:none;position:absolute;top:100%;left:0;right:0;background:var(--bg2);flex-direction:column;gap:0;margin:0;padding:8px 12px 14px;border:1px solid var(--line);border-radius:0 0 16px 16px;box-shadow:0 16px 30px rgba(0,0,0,.10)}
  .nav-links a{display:block;padding:13px 14px;border-radius:11px;font-size:1.02rem}
  .nav-toggle:checked ~ .nav-links{display:flex}
  .grid2{grid-template-columns:1fr}
  main{padding:32px 0 80px}
  .wrap{padding-left:18px;padding-right:18px}
  .nav-inner{padding:12px 18px}
  h1{font-size:1.7rem}
  .panel,.toolcard{padding:20px;border-radius:16px}
  .btn{width:100%;text-align:center}
  .btnrow{flex-direction:column;align-items:stretch;gap:8px}
  .btnrow .btn{width:100%}
  table{display:block;overflow-x:auto;white-space:nowrap}
  .crumb{flex-wrap:wrap;gap:4px}
  ul.tools{grid-template-columns:1fr;gap:12px}
}
.visually-hidden{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}