:root{
  --bg:#0b1020;
  --panel:#111832;
  --text:#e8ecff;
  --muted:#aab3d6;
  --brand:#6aa6ff;
  --brand-2:#8fe6ff;
}

*{ box-sizing: border-box; }

html,body{
  padding:0; margin:0;
  font-family: "Poppins", system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  color: var(--text);
  background: radial-gradient(1200px 600px at 10% -5%, rgba(106,166,255,.15), transparent 60%),
              radial-gradient(800px 400px at 120% 10%, rgba(143,230,255,.12), transparent 60%),
              var(--bg);
}

.container{ max-width: 1100px; margin: 0 auto; padding: 0 20px; }

.site-header{
  background: linear-gradient(90deg, rgba(17,24,50,.8), rgba(17,24,50,.5));
  backdrop-filter: blur(6px);
  position: sticky; top: 0; z-index: 10;
  border-bottom: 1px solid rgba(255,255,255,.06);
}

.nav{ display:flex; align-items:center; justify-content:space-between; padding:16px 0; }
.logo{ margin:0; font-size:1.25rem; font-weight:700; letter-spacing:.5px; }

nav a{
  color: var(--text); text-decoration:none; margin-left:18px; opacity:.85;
  padding: 8px 10px; border-radius: 8px; transition: .2s ease;
}
nav a:hover{ opacity:1; background: rgba(255,255,255,.06); }
nav a.active{ background: rgba(255,255,255,.12); }

.hero{
  padding: 56px 0 24px;
  text-align: center;
}
.hero h2{ font-size:2.2rem; margin:.2rem 0 .5rem; }
.hero p{ color: var(--muted); max-width:760px; margin: 0 auto 1.2rem; }

.cta-group{ display:flex; gap:12px; justify-content:center; flex-wrap:wrap; }

.btn{
  display:inline-block; padding:12px 18px; border-radius:12px;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color:#051024; font-weight:600; text-decoration:none; border:0; cursor:pointer;
  box-shadow: 0 6px 18px rgba(138,195,255,.25);
}
.btn:hover{ filter: brightness(1.06); }
.btn.btn-secondary{
  background: transparent; color: var(--text);
  border: 1px solid rgba(255,255,255,.2);
}

.grid{
  display:grid; grid-template-columns: repeat(auto-fit, minmax(250px,1fr));
  gap:18px; padding: 24px 0 56px;
}

.card{
  background: linear-gradient(180deg, rgba(255,255,255,.05), rgba(255,255,255,.03));
  border: 1px solid rgba(255,255,255,.08);
  border-radius: 16px; padding: 18px;
  box-shadow: 0 8px 28px rgba(0,0,0,.25);
}
.card h3{ margin-top:0; }

.topic{
  background: rgba(255,255,255,.03);
  border: 1px solid rgba(255,255,255,.08);
  padding: 18px; border-radius: 14px; margin: 14px 0;
}
.page-title{ margin: 24px 0 12px; }

.quiz label{
  display:block; padding:8px 10px; border-radius:10px; margin:6px 0;
  background: rgba(255,255,255,.03); border: 1px solid rgba(255,255,255,.08);
  cursor:pointer;
}
.quiz input[type="radio"]{ margin-right:8px; accent-color: #6aa6ff; }
.result{ margin: 18px 0; font-weight:600; }

.text-link{ color: var(--brand-2); text-decoration:none; }
.text-link:hover{ text-decoration: underline; }

.site-footer{
  border-top: 1px solid rgba(255,255,255,.06);
  margin-top: 36px;
  background: rgba(0,0,0,.15);
}
.site-footer .container{ padding: 14px 20px; color: var(--muted); }

.spacer{ height:8px; }