:root{
  --bg:#0b0d12;
  --panel:#111624;
  --text:#eef2ff;
  --muted:#b8c0e0;
  --line:rgba(255,255,255,.10);
  --accent:#7aa2ff;
  --accent2:#9bf6ff;
  --shadow:0 10px 40px rgba(0,0,0,.35);
  --radius:16px;
  --wrap:1100px;
  --sans: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family:var(--sans);
  background:
    radial-gradient(900px 500px at 20% -10%, rgba(122,162,255,.28), transparent 60%),
    radial-gradient(900px 500px at 95% 10%, rgba(155,246,255,.12), transparent 60%),
    var(--bg);
  color:var(--text);
  line-height:1.55;
}

a{color:inherit}
.wrap{max-width:var(--wrap); margin:0 auto; padding:0 20px}
.skip{
  position:absolute; left:-999px; top:auto; width:1px; height:1px; overflow:hidden;
}
.skip:focus{left:20px; top:12px; width:auto; height:auto; padding:10px 12px; background:var(--panel); border:1px solid var(--line); border-radius:10px; z-index:999}

.header{
  position:sticky; top:0; z-index:50;
  backdrop-filter: blur(10px);
  background: linear-gradient(to bottom, rgba(11,13,18,.85), rgba(11,13,18,.55));
  border-bottom:1px solid var(--line);
}
.header__inner{display:flex; align-items:center; justify-content:space-between; gap:16px; padding:14px 0}

.brand{display:flex; align-items:center; gap:10px; text-decoration:none}
.brand__mark{
  width:22px; height:22px; border-radius:7px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  box-shadow: 0 10px 25px rgba(122,162,255,.25);
}
.brand__text{font-weight:700; letter-spacing:.2px}

.nav{display:flex; align-items:center; gap:18px}
.nav a{color:var(--muted); text-decoration:none; font-weight:600}
.nav a[aria-current="page"]{color:var(--text)}
.nav a:hover{color:var(--text)}

.menu{
  display:none;
  width:44px; height:38px;
  background:transparent; border:1px solid var(--line);
  border-radius:12px; color:var(--text);
}
.menu span{display:block; width:18px; height:2px; background:var(--text); margin:5px auto; opacity:.85}

.nav--mobile{
  display:none;
  padding:10px 0 18px;
  border-top:1px solid var(--line);
}
.nav--mobile a{
  display:block;
  padding:10px 0;
  color:var(--muted);
  text-decoration:none;
  font-weight:650;
}
.nav--mobile a:hover{color:var(--text)}

.hero{padding:54px 0 22px}
.hero__grid{display:grid; grid-template-columns: 1.25fr .75fr; gap:28px; align-items:start}
.kicker{color:var(--muted); letter-spacing:.18em; text-transform:uppercase; font-size:.78rem; margin:0 0 10px}
h1{font-size:clamp(2.1rem, 4vw, 3.2rem); line-height:1.1; margin:0 0 14px}
.lede{color:var(--muted); font-size:1.08rem; margin:0 0 18px; max-width:60ch}

.cta{display:flex; gap:12px; flex-wrap:wrap; margin:18px 0 18px}
.btn{
  display:inline-flex; align-items:center; justify-content:center;
  padding:12px 16px; border-radius:14px;
  background: linear-gradient(135deg, rgba(122,162,255,.95), rgba(155,246,255,.75));
  color:#071019; font-weight:800; text-decoration:none;
  border:1px solid rgba(255,255,255,.12);
  box-shadow: 0 14px 32px rgba(0,0,0,.28);
}
.btn--ghost{
  background: transparent;
  color: var(--text);
  border: 1px solid var(--line);
  box-shadow:none;
}
.btn--small{padding:10px 12px; border-radius:12px; font-weight:800}
.btn:hover{filter:brightness(1.03)}
.btn--ghost:hover{border-color:rgba(255,255,255,.18)}

.bullets{margin:16px 0 0; padding-left:18px; color:var(--muted)}
.bullets li{margin:8px 0}

.card{
  background: linear-gradient(180deg, rgba(17,22,36,.95), rgba(17,22,36,.72));
  border:1px solid var(--line);
  border-radius:var(--radius);
  box-shadow: var(--shadow);
}
.pad{padding:18px}
.hero__card .fineprint{margin:12px 0 0; color:var(--muted); font-size:.92rem}
.cover{
  padding:14px;
}
.cover__placeholder{
  height:320px; border-radius:14px;
  border:1px dashed rgba(255,255,255,.18);
  display:flex; flex-direction:column;
  align-items:center; justify-content:center;
  color:var(--muted);
}

.section{padding:26px 0}
.section h2{margin:0 0 14px; font-size:1.5rem}
.grid{display:grid; gap:14px}
.grid--3{grid-template-columns: repeat(3, 1fr)}
.grid--2{grid-template-columns: repeat(2, 1fr)}
.panel{
  display:block;
  padding:16px;
  border-radius:var(--radius);
  border:1px solid var(--line);
  text-decoration:none;
  background: rgba(255,255,255,.03);
}
.panel h3{margin:0 0 6px}
.panel p{margin:0; color:var(--muted)}
.panel:hover{background: rgba(255,255,255,.05); border-color:rgba(255,255,255,.14)}

.page{padding:30px 0 40px}
.page h1{font-size:2.2rem; margin:0 0 10px}
.stack{display:grid; gap:14px}

.book{display:grid; grid-template-columns: 260px 1fr; gap:18px; align-items:start}
.book__cover .cover__placeholder{height:340px}
.book__title{margin:0 0 6px}
.book__meta{margin:0 0 12px; color:var(--muted)}
.book__links{display:flex; gap:10px; flex-wrap:wrap; margin:12px 0 0}

.embed{
  padding:14px;
  border-radius:14px;
  border:1px dashed rgba(255,255,255,.18);
  background: rgba(255,255,255,.03);
  color:var(--muted);
}

.fineprint{color:var(--muted); font-size:.92rem}

.footer{border-top:1px solid var(--line); padding:22px 0 30px; margin-top:18px}
.footer__inner{display:flex; justify-content:space-between; gap:12px; align-items:center; flex-wrap:wrap}
.footer__links{display:flex; gap:14px}
.footer__links a{color:var(--muted); text-decoration:none}
.footer__links a:hover{color:var(--text)}

@media (max-width: 860px){
  .hero__grid{grid-template-columns:1fr; }
  .grid--3{grid-template-columns:1fr}
  .grid--2{grid-template-columns:1fr}
  .book{grid-template-columns:1fr}
  .nav{display:none}
  .menu{display:block}
  .nav--mobile{display:block}
}