:root {
  --green:#16a34a;
  --green-dark:#087f3d;
  --red:#dc2626;
  --orange:#f97316;
  --blue:#2563eb;
  --ink:#172033;
  --muted:#667085;
  --line:#e5e7eb;
  --soft:#f6f8fb;
  --white:#fff;
  --shadow:0 12px 35px rgba(15,23,42,.08);
  --radius:18px;
  --max:1120px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;
  color:var(--ink);
  background:#f8fafc;
  line-height:1.72;
}
a{color:inherit}
img{max-width:100%;display:block}
.container{width:min(var(--max),calc(100% - 36px));margin:auto}
.topbar{
  position:sticky;top:0;z-index:50;background:rgba(255,255,255,.94);
  backdrop-filter:blur(12px);border-bottom:1px solid var(--line)
}
.topbar-inner{height:66px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand{font-weight:900;text-decoration:none;letter-spacing:-.3px}
.brand span:first-child{color:var(--green)}
.brand span:last-child{color:var(--red)}
.nav{display:flex;gap:18px;align-items:center;font-size:14px}
.nav a{text-decoration:none;color:#475467}
.nav a:hover{color:var(--green)}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:12px 18px;border-radius:11px;text-decoration:none;font-weight:800;
  border:1px solid transparent;transition:.2s
}
.btn-green{background:var(--green);color:#fff}
.btn-green:hover{background:var(--green-dark);transform:translateY(-1px)}
.btn-light{background:#fff;border-color:var(--line)}
.hero{
  padding:78px 0 55px;
  background:
    radial-gradient(circle at 80% 20%,rgba(34,197,94,.12),transparent 28%),
    radial-gradient(circle at 15% 0%,rgba(249,115,22,.10),transparent 25%),
    #fff;
}
.eyebrow{
  display:inline-flex;padding:7px 12px;border-radius:999px;background:#ecfdf3;
  color:#087f3d;font-size:13px;font-weight:900;margin-bottom:18px
}
h1{font-size:clamp(36px,5vw,60px);line-height:1.05;letter-spacing:-2px;margin:0 0 20px}
.hero h1 .g{color:var(--green)}
.hero h1 .r{color:var(--red)}
.lead{font-size:19px;color:#475467;max-width:780px;margin:0 0 28px}
.hero-actions{display:flex;flex-wrap:wrap;gap:12px}
.quick{margin-top:34px;display:grid;grid-template-columns:repeat(4,1fr);gap:12px}
.quick-card{background:#fff;border:1px solid var(--line);border-radius:15px;padding:17px;box-shadow:0 7px 22px rgba(15,23,42,.04)}
.quick-card b{display:block;font-size:16px;margin-bottom:4px}
.quick-card small{color:var(--muted)}
.layout{display:grid;grid-template-columns:250px minmax(0,1fr);gap:34px;align-items:start;margin-top:36px}
.sidebar{
  position:sticky;top:84px;background:#fff;border:1px solid var(--line);
  border-radius:16px;padding:18px;box-shadow:var(--shadow)
}
.sidebar-title{font-weight:900;margin-bottom:10px}
.sidebar a{display:block;text-decoration:none;padding:8px 10px;border-radius:8px;color:#667085;font-size:14px}
.sidebar a:hover{background:#f2f4f7;color:var(--ink)}
.sidebar a.active{
  background:#f0fdf4;
  color:#087f3d;
  font-weight:800;
  border-left:3px solid var(--green);
  padding-left:7px;
}
.content{min-width:0}
.section{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:34px;margin-bottom:24px;box-shadow:var(--shadow)
}
.kicker{font-size:12px;font-weight:900;letter-spacing:1.4px;color:#667085;text-transform:uppercase}
h2{font-size:31px;line-height:1.2;letter-spacing:-.7px;margin:7px 0 12px}
h3{font-size:21px;line-height:1.3;margin:26px 0 8px}
p{margin:9px 0 14px}
.muted{color:var(--muted)}
.callout{padding:18px 20px;border-radius:14px;margin:20px 0;border-left:5px solid var(--blue);background:#eff6ff}
.callout.green{border-left-color:var(--green);background:#f0fdf4}
.callout.red{border-left-color:var(--red);background:#fef2f2}
.callout.orange{border-left-color:var(--orange);background:#fff7ed}
.callout strong{display:block;margin-bottom:4px}
.rule{
  display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:20px 0
}
.rule-card{border:1px solid var(--line);border-radius:15px;padding:20px}
.rule-card.green{background:#f0fdf4;border-color:#bbf7d0}
.rule-card.white{background:#f8fafc}
.rule-card.red{background:#fef2f2;border-color:#fecaca}
.icon{font-size:28px;margin-bottom:5px}
.demo{margin:22px 0;border:1px solid #dfe3e8;border-radius:15px;overflow:hidden;background:#fff}
.demo img{width:100%;height:auto}
.caption{padding:14px 16px;background:#f8fafc;border-top:1px solid var(--line);font-size:14px;color:#475467}
.caption b{color:var(--ink)}
.legend{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin-top:15px}
.legend-item{border:1px solid var(--line);border-radius:12px;padding:15px}
.legend-item b{display:block;margin-bottom:3px}
.step-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:10px;margin:22px 0}
.step{border:1px solid var(--line);border-radius:15px;padding:17px;background:#fff}
.step-num{width:34px;height:34px;border-radius:10px;background:#eef2ff;color:#3730a3;display:grid;place-items:center;font-weight:900;margin-bottom:10px}
.step h3{font-size:17px;margin:0 0 5px}
.checklist{display:grid;gap:9px;margin:15px 0}
.check{padding:13px 15px;border:1px solid var(--line);border-radius:11px;background:#fafafa}
.check::before{content:"✓";font-weight:900;color:var(--green);margin-right:9px}
.compare{width:100%;border-collapse:collapse;margin:18px 0;font-size:14px}
.compare th,.compare td{border:1px solid var(--line);padding:13px;text-align:left;vertical-align:top}
.compare th{background:#f8fafc}
.badge{display:inline-flex;padding:4px 9px;border-radius:999px;font-size:12px;font-weight:900}
.badge-green{background:#dcfce7;color:#166534}
.badge-red{background:#fee2e2;color:#991b1b}
.badge-gray{background:#eef2f6;color:#475467}
.faq{border-top:1px solid var(--line)}
details{border-bottom:1px solid var(--line);padding:16px 0}
summary{cursor:pointer;font-weight:800}
.toc-mobile{display:none}
.footer{background:#111827;color:#d1d5db;padding:45px 0;margin-top:40px}
.footer a{color:#fff;text-decoration:none}
.warning{background:#fff7ed;border:1px solid #fed7aa;border-radius:15px;padding:20px}
.mini-flow{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin:18px 0}
.mini-flow span{padding:10px 13px;border-radius:10px;background:#f3f4f6;font-weight:800}
.mini-flow .arrow{background:transparent;padding:0}
.backtop{position:fixed;right:20px;bottom:20px;width:42px;height:42px;border-radius:50%;border:1px solid var(--line);background:#fff;box-shadow:var(--shadow);display:grid;place-items:center;text-decoration:none;font-weight:900}
@media(max-width:900px){
  .layout{grid-template-columns:1fr}
  .sidebar{display:none}
  .toc-mobile{display:block;margin-bottom:20px}
  .toc-mobile select{width:100%;padding:12px;border:1px solid var(--line);border-radius:10px;background:#fff}
  .quick{grid-template-columns:repeat(2,1fr)}
  .step-grid{grid-template-columns:repeat(2,1fr)}
  .nav{display:none}
}
@media(max-width:600px){
  .container{width:min(var(--max),calc(100% - 24px))}
  .hero{padding:52px 0 38px}
  .section{padding:23px 18px;border-radius:15px}
  h2{font-size:26px}
  .lead{font-size:17px}
  .quick,.rule,.legend{grid-template-columns:1fr}
  .step-grid{grid-template-columns:1fr}
}