:root{
    --navy:#14263F;
    --navy-2:#1E3A5F;
    --navy-soft:#274B78;
    --red:#C8102E;
    --red-soft:#FDEBED;
    --gold:#B8860B;
    --gold-soft:#FBF3DF;
    --ink:#24303E;
    --muted:#5A6B7C;
    --bg:#FFFFFF;
    --bg-soft:#F4F6F9;
    --line:#E2E7EE;
    --radius:10px;
    --shadow:0 10px 30px rgba(20,38,63,.10);
  }
  *{box-sizing:border-box;margin:0;padding:0;}
  html{scroll-behavior:smooth;}
  body{
    font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans",sans-serif;
    color:var(--ink);background:var(--bg);line-height:1.6;font-size:16px;-webkit-font-smoothing:antialiased;
  }
  a{color:var(--navy-soft);text-decoration:none;}
  a:hover{text-decoration:underline;}

  /* Top bar */
  .topbar{position:sticky;top:0;z-index:50;background:rgba(20,38,63,.97);color:#fff;box-shadow:0 2px 12px rgba(0,0,0,.18);backdrop-filter:blur(6px);}
  .topbar-inner{max-width:1120px;margin:0 auto;padding:10px 24px;display:flex;align-items:center;gap:14px;}
  .topbar .logo{height:38px;width:auto;display:block;filter:drop-shadow(0 1px 2px rgba(0,0,0,.3));}
  .topbar .brand{font-size:15px;font-weight:700;letter-spacing:.3px;line-height:1.2;}
  .topbar .brand small{display:block;font-weight:400;font-size:12px;color:#C9D4E3;}
  .topbar .chip{margin-left:auto;font-size:12px;font-weight:700;letter-spacing:.8px;background:var(--red);color:#fff;padding:5px 12px;border-radius:999px;white-space:nowrap;}
  @media (max-width:640px){.topbar .brand small{display:none;}}

  /* Hero */
  .hero{background:linear-gradient(180deg,#F7F9FC 0%,#FFFFFF 100%);border-bottom:1px solid var(--line);padding:44px 24px 40px;}
  .hero-inner{max-width:1120px;margin:0 auto;display:grid;grid-template-columns:400px 1fr;gap:44px;align-items:center;}
  .hero-cover{border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);border:1px solid var(--line);background:#fff;}
  .hero-cover img{display:block;width:100%;height:auto;}
  .hero-kicker{color:var(--gold);font-weight:800;letter-spacing:2.5px;font-size:13px;text-transform:uppercase;}
  .hero-chip{display:inline-block;margin-top:12px;background:var(--red);color:#fff;font-size:13px;font-weight:700;letter-spacing:1px;padding:5px 14px;border-radius:6px;}
  .hero h1{font-size:clamp(30px,4.6vw,46px);line-height:1.12;color:var(--navy);margin:16px 0 10px;font-weight:800;letter-spacing:-.5px;}
  .hero .hero-sub{font-size:15px;font-weight:700;letter-spacing:2.5px;color:var(--navy-2);text-transform:uppercase;}
  .hero .hero-co{margin-top:14px;color:var(--muted);font-size:14px;}
  .hero-strap{margin-top:22px;display:flex;gap:8px;flex-wrap:wrap;}
  .hero-strap span{font-size:12px;font-weight:700;letter-spacing:1.2px;color:var(--navy);border:1px solid var(--line);background:#fff;padding:6px 14px;border-radius:999px;}
  @media (max-width:860px){.hero-inner{grid-template-columns:1fr;gap:26px;}.hero-cover{max-width:420px;margin:0 auto;}}

  .wrap{max-width:1120px;margin:0 auto;padding:36px 24px 60px;}

  /* About */
  .about{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-bottom:36px;}
  @media (max-width:860px){.about{grid-template-columns:1fr;}}
  .callout{border-radius:var(--radius);padding:18px 20px;border:1px solid;}
  .callout .c-title{font-weight:800;letter-spacing:.4px;text-transform:uppercase;font-size:13px;display:flex;align-items:center;gap:8px;margin-bottom:8px;}
  .callout.scope{background:var(--bg-soft);border-color:var(--line);}
  .callout.scope .c-title{color:var(--navy-2);}
  .callout.note{background:var(--gold-soft);border-color:#E8D49B;color:#6B5410;}
  .callout.note .c-title{color:var(--gold);}

  /* Parts */
  .part{margin-bottom:34px;}
  .part-head{display:flex;align-items:center;gap:14px;margin-bottom:14px;padding-bottom:10px;border-bottom:2px solid var(--line);}
  .part-num{flex:none;min-width:42px;height:42px;border-radius:8px;background:var(--navy);color:#fff;font-weight:800;font-size:17px;display:flex;align-items:center;justify-content:center;}
  .part-head h2{font-size:21px;color:var(--navy);font-weight:800;letter-spacing:-.2px;}
  .part-head .range{margin-left:auto;font-size:12.5px;font-weight:700;letter-spacing:1px;color:var(--muted);background:#fff;border:1px solid var(--line);padding:4px 10px;border-radius:999px;white-space:nowrap;}

  .chapters{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:10px;}
  .ch-link{
    display:flex;gap:12px;align-items:baseline;padding:11px 14px;border:1px solid var(--line);
    border-radius:8px;background:#fff;color:var(--ink);transition:all .15s ease;
  }
  .ch-link:hover{border-color:var(--navy-soft);background:var(--bg-soft);text-decoration:none;transform:translateY(-1px);box-shadow:0 4px 12px rgba(20,38,63,.08);}
  .ch-num{flex:none;font-weight:800;color:var(--red);font-size:13px;letter-spacing:.5px;min-width:32px;}
  .ch-link span.title{font-size:14.5px;line-height:1.35;}

  /* Footer */
  footer{background:var(--navy);color:#C9D4E3;padding:44px 24px 30px;margin-top:30px;}
  .foot-inner{max-width:1120px;margin:0 auto;display:flex;flex-wrap:wrap;gap:24px;align-items:center;justify-content:space-between;}
  .foot-brand{font-size:17px;font-weight:800;color:#fff;letter-spacing:.4px;}
  .foot-strap{font-size:12.5px;letter-spacing:2.2px;font-weight:700;color:#F0B429;}
  .foot-co{font-size:13.5px;}
  .foot-co a{color:#fff;text-decoration:underline;}
  .foot-line{margin-top:24px;border-top:1px solid rgba(255,255,255,.15);padding-top:16px;font-size:12.5px;color:#8FA3BA;text-align:center;}

  @media print{
    .topbar{display:none !important;}
    .hero{padding:10px 0;border:none;}
    .hero-inner{grid-template-columns:1fr;}
    .ch-link{border-color:#ccc;}
    footer{background:#fff;color:#333;}
  }

.hero-co a{font-weight:700}
.hero-actions{margin-top:22px}
.download-button{display:inline-block;background:var(--red);color:#fff;padding:11px 18px;border-radius:8px;font-weight:800;box-shadow:0 5px 14px rgba(200,16,46,.22)}
.download-button:hover{color:#fff;text-decoration:none;transform:translateY(-1px)}
@media(max-width:640px){.part-head{align-items:flex-start;flex-wrap:wrap}.part-head h2{flex:1;min-width:180px}.part-head .range{margin-left:56px}}