:root{
    --bg:#f6f5f2; --card:#fff; --ink:#1b1b1b; --muted:#6b6b6b; --line:#e4e2dc;
    --accent:#1f5eff; --accent-soft:#e8eeff; --warn:#a15c00; --warn-soft:#fff4e2;
    --ru:#7a4bd6;
  }
  *{box-sizing:border-box}
  html{scroll-behavior:smooth}
  body{margin:0;background:var(--bg);color:var(--ink);
    font:16px/1.55 -apple-system,BlinkMacSystemFont,"Segoe UI",Inter,Roboto,sans-serif}
  .wrap{max-width:1180px;margin:0 auto;padding:40px 24px 80px;display:grid;grid-template-columns:240px 1fr;gap:40px}
  header.top{grid-column:1/-1}
  .eyebrow{font-size:13px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin:0 0 6px}
  h1{font-size:40px;line-height:1.1;margin:0 0 12px;letter-spacing:-.02em}
  .lead{font-size:18px;color:#3a3a3a;max-width:760px;margin:0}
  .howto{margin-top:20px;display:flex;flex-wrap:wrap;gap:10px}
  .pill{background:var(--card);border:1px solid var(--line);border-radius:999px;padding:6px 14px;font-size:14px}
  .ru{color:var(--ru);font-weight:600}
  nav.toc{position:sticky;top:24px;align-self:start;font-size:14px}
  nav.toc p{margin:0 0 8px;color:var(--muted);font-size:12px;text-transform:uppercase;letter-spacing:.08em}
  nav.toc{counter-reset:t}
  nav.toc ol{list-style:none;margin:0;padding:0}
  nav.toc li{counter-increment:t}
  nav.toc li.ref{counter-increment:none}
  nav.toc a{display:flex;gap:10px;padding:7px 10px;border-radius:8px;color:var(--ink);text-decoration:none}
  nav.toc a::before{content:counter(t);color:var(--muted);min-width:14px;font-variant-numeric:tabular-nums}
  nav.toc a:hover,nav.toc a.on{background:var(--card)}
  nav.toc a.ref::before{content:"≡"}
  main{min-width:0}
  section.step{background:var(--card);border:1px solid var(--line);border-radius:16px;margin:0 0 28px;overflow:hidden;scroll-margin-top:20px}
  .step-head{display:flex;align-items:baseline;gap:14px;padding:22px 26px 14px}
  .num{font-size:13px;font-weight:700;color:var(--accent);background:var(--accent-soft);border-radius:6px;padding:2px 8px;font-variant-numeric:tabular-nums}
  h2{font-size:22px;margin:0;letter-spacing:-.01em}
  .why{color:var(--muted);margin:0;padding:0 26px 16px;max-width:780px}
  .video{position:relative;background:#111;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
  .video video{display:block;width:100%;height:auto;max-height:640px;object-fit:contain;background:#fff;cursor:zoom-in}
  .video .len{position:absolute;right:12px;top:12px;background:rgba(0,0,0,.6);color:#fff;font-size:12px;padding:3px 8px;border-radius:6px;pointer-events:none}
  .video.narrow video{max-width:720px;margin:0 auto}
  .video.narrow{background:#fff}
  .body{display:grid;grid-template-columns:1.25fr 1fr;gap:28px;padding:22px 26px 26px}
  .body h3{font-size:12px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);margin:0 0 10px}
  ol.steps{margin:0;padding-left:20px}
  ol.steps li{margin:0 0 8px;padding-left:4px}
  .result p{margin:0 0 10px}
  .note{background:var(--warn-soft);border-radius:10px;padding:12px 14px;font-size:15px;margin-top:12px}
  .note b{color:var(--warn)}
  .icons{display:grid;grid-template-columns:auto 1fr;gap:6px 12px;font-size:15px;margin:0}
  .icons dt{font-size:18px;line-height:1.4;text-align:center}
  .icons dd{margin:0}
  table{width:100%;border-collapse:collapse;font-size:15px}
  th,td{text-align:left;padding:10px 12px;border-top:1px solid var(--line);vertical-align:top}
  th{font-size:12px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);border-top:none}
  td:first-child{min-width:180px}
  .tbl{padding:6px 14px 18px;overflow-x:auto}
  .tag{display:inline-block;font-size:12px;border-radius:6px;padding:1px 7px;margin-left:6px;background:#eee;color:#555}
  .tag.req{background:var(--accent-soft);color:var(--accent)}
  dialog{border:none;padding:0;background:transparent;max-width:96vw;max-height:96vh}
  dialog::backdrop{background:rgba(0,0,0,.85)}
  dialog video{max-width:96vw;max-height:92vh;display:block;background:#fff}
  dialog button{position:fixed;top:14px;right:18px;font-size:28px;background:none;border:none;color:#fff;cursor:pointer}
  @media (max-width:900px){
    .wrap{grid-template-columns:1fr;gap:20px;padding-top:24px}
    nav.toc{position:static}
    .body{grid-template-columns:1fr}
    h1{font-size:30px}
  }

  /* multi-page additions */
  .back{display:inline-block;margin:0 0 14px;font-size:14px;color:var(--muted);text-decoration:none}
  .back:hover{color:var(--accent)}
  .group-head{margin:40px 0 16px;scroll-margin-top:20px}
  .group-head:first-child{margin-top:0}
  .group-head h2{font-size:28px;letter-spacing:-.02em}
  .group-head p{color:var(--muted);margin:6px 0 0;max-width:780px}
  nav.toc .grp{display:block;margin:14px 0 4px;padding:0 10px;font-size:12px;font-weight:600;color:var(--muted);text-transform:none;letter-spacing:0}
  .pager{display:flex;justify-content:space-between;gap:16px;margin-top:8px}
  .pager a{flex:1;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px 18px;text-decoration:none;color:var(--ink)}
  .pager a small{display:block;color:var(--muted);font-size:12px;text-transform:uppercase;letter-spacing:.08em}
  .pager a.next{text-align:right}
  .pager a:hover{border-color:var(--accent)}
  .hub{max-width:1180px;margin:0 auto;padding:40px 24px 80px}
  .topics{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:16px;margin-top:32px}
  .topic{display:flex;gap:16px;background:var(--card);border:1px solid var(--line);border-radius:16px;padding:20px 22px;text-decoration:none;color:var(--ink);transition:border-color .15s,transform .15s}
  .topic:hover{border-color:var(--accent);transform:translateY(-1px)}
  .topic .ic{font-size:28px;line-height:1}
  .topic h2{font-size:19px;margin:0 0 4px}
  .topic p{margin:0;color:var(--muted);font-size:15px}
  .topic .meta{margin-top:8px;font-size:13px;color:var(--accent)}
  @media (max-width:900px){.pager{flex-direction:column}}