:root{
  --bg:#f4f7fb;--card:#ffffff;--text:#102033;--muted:#607084;--line:#dfe8f4;
  --blue:#0f5ea8;--blue2:#0b7bd3;--navy:#082646;--gold:#f7c948;--green:#0f9f6e;--red:#c53d3d;
  --shadow:0 18px 50px rgba(10,35,70,.12);--radius:24px;
}
*{box-sizing:border-box}body{margin:0;font-family:Inter,Arial,sans-serif;background:radial-gradient(circle at top left,#dff0ff 0,#f5f8fc 36%,#f7f9fc 100%);color:var(--text);line-height:1.65}a{color:inherit}.shell{width:min(1120px,calc(100% - 32px));margin:0 auto}.hero{position:relative;overflow:hidden;background:linear-gradient(135deg,var(--navy),#0a477d 55%,#0d82c8);color:white;padding:32px 0 44px;border-bottom-left-radius:34px;border-bottom-right-radius:34px;box-shadow:var(--shadow)}.hero:before{content:"";position:absolute;inset:-20%;background:radial-gradient(circle at 84% 20%,rgba(247,201,72,.32),transparent 24%),radial-gradient(circle at 16% 80%,rgba(255,255,255,.14),transparent 28%);pointer-events:none}.topbar,.hero-grid{position:relative;z-index:1}.topbar{display:flex;justify-content:space-between;gap:18px;align-items:center;margin-bottom:38px}.brand{display:flex;align-items:center;gap:16px}.crest{width:76px;height:76px;background:white;border-radius:20px;padding:9px;box-shadow:0 10px 30px rgba(0,0,0,.18);object-fit:contain}.brand small{display:block;color:#bfdef7;font-weight:700;text-transform:uppercase;letter-spacing:.11em;font-size:12px}.brand strong{display:block;font-size:18px}.badge{display:inline-flex;gap:9px;align-items:center;padding:10px 14px;border:1px solid rgba(255,255,255,.22);background:rgba(255,255,255,.11);border-radius:999px;backdrop-filter:blur(8px);font-weight:700}.hero-grid{display:grid;grid-template-columns:1.35fr .65fr;gap:28px;align-items:end}.hero h1{font-size:clamp(34px,5vw,58px);line-height:1.05;margin:0 0 18px;letter-spacing:-.04em}.lead{font-size:clamp(17px,2.1vw,21px);max-width:820px;margin:0;color:#e9f5ff}.hero-card{background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.2);border-radius:var(--radius);padding:22px;backdrop-filter:blur(10px)}.hero-card b{font-size:34px;display:block;line-height:1}.hero-card span{color:#d8efff}.nav{display:flex;gap:10px;flex-wrap:wrap;margin:28px 0}.nav a,.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;text-decoration:none;border-radius:999px;padding:11px 16px;background:white;border:1px solid var(--line);box-shadow:0 8px 24px rgba(20,55,90,.08);font-weight:800;color:var(--navy);cursor:pointer}.btn.primary,.nav a:hover{background:linear-gradient(135deg,var(--blue),var(--blue2));color:white;border-color:transparent}.btn.dark{background:#102033;color:white}.btn.ghost{background:transparent;border-color:#b8c8dc}.main{padding:34px 0 60px}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.card{background:rgba(255,255,255,.92);border:1px solid var(--line);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow)}.exercise-card{text-decoration:none;display:flex;flex-direction:column;min-height:230px;transition:.18s}.exercise-card:hover{transform:translateY(-4px)}.num{width:42px;height:42px;border-radius:14px;display:grid;place-items:center;background:#e8f4ff;color:var(--blue);font-weight:900;margin-bottom:16px}.tag{display:inline-flex;align-self:flex-start;margin-top:auto;padding:7px 10px;background:#f0f7ff;border:1px solid #d8eaff;border-radius:999px;color:var(--blue);font-size:13px;font-weight:800}.kicker{font-size:13px;text-transform:uppercase;letter-spacing:.12em;color:var(--blue);font-weight:900}.h2{font-size:clamp(26px,3.5vw,38px);line-height:1.12;margin:0 0 14px}.muted{color:var(--muted)}.layout{display:grid;grid-template-columns:280px 1fr;gap:22px}.side{position:sticky;top:18px;align-self:start}.side a{display:block;text-decoration:none;padding:10px 12px;border-radius:12px;color:var(--muted);font-weight:700}.side a:hover{background:#eef6ff;color:var(--blue)}.step{display:flex;gap:14px;margin:18px 0;padding:18px;border:1px solid var(--line);background:#fbfdff;border-radius:18px}.step b{width:34px;height:34px;flex:0 0 34px;border-radius:12px;background:var(--blue);color:white;display:grid;place-items:center}.callout{border-left:5px solid var(--gold);background:#fffbeb;padding:16px 18px;border-radius:16px;margin:16px 0}.warning{border-left-color:var(--red);background:#fff1f1}.success{border-left-color:var(--green);background:#effcf7}.prompt,pre{white-space:pre-wrap;background:#0d1f33;color:#eaf6ff;border-radius:18px;padding:18px;overflow:auto;font-size:14px}.copybar{display:flex;gap:10px;flex-wrap:wrap;margin:10px 0 18px}textarea,input,select{width:100%;border:1px solid #cfdceb;border-radius:16px;padding:14px;font:inherit;background:white}textarea{min-height:150px}.quiz-option{display:block;width:100%;text-align:left;background:white;border:1px solid var(--line);border-radius:16px;padding:14px 16px;margin:10px 0;cursor:pointer}.quiz-option:hover{border-color:var(--blue);background:#f4faff}.quiz-option.correct{background:#ebfff6;border-color:#20a874}.quiz-option.wrong{background:#fff0f0;border-color:#d84d4d}.progress{height:10px;background:#e0e9f4;border-radius:999px;overflow:hidden;margin:14px 0}.progress span{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--blue),var(--green));transition:.25s}.footer{padding:26px 0;color:var(--muted);font-size:14px}.mini-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}.pill{display:inline-block;padding:6px 10px;border-radius:999px;background:#eef6ff;color:var(--blue);font-weight:800;font-size:12px}.table{width:100%;border-collapse:collapse;background:white;border-radius:18px;overflow:hidden}.table th,.table td{border-bottom:1px solid var(--line);padding:12px;text-align:left;vertical-align:top}.table th{background:#f0f7ff}.result{font-weight:900;margin-top:16px}.hide{display:none!important}@media(max-width:860px){.hero-grid,.layout,.grid,.mini-grid{grid-template-columns:1fr}.topbar{align-items:flex-start;flex-direction:column}.side{position:relative}.hero{border-radius:0 0 24px 24px}.card{padding:20px}}