:root{
  --bg:#f6f7fb;
  --card:#ffffff;
  --text:#111827;
  --muted:#6b7280;
  --accent:#6366f1;
  --radius:14px;
  --shadow: 0 6px 18px rgba(16,24,40,0.08);
  --transition:300ms cubic-bezier(.2,.9,.3,1);
}

[data-theme="dark"]{
  --bg:#0b1020;
  --card:#0f1724;
  --text:#e6eef8;
  --muted:#9aa6bf;
  --accent:#7c3aed;
  --shadow: 0 6px 18px rgba(2,6,23,0.6);
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family:Inter,system-ui,Segoe UI,Roboto,"Helvetica Neue",Arial;
  background:linear-gradient(180deg,var(--bg),#fff);
  color:var(--text);
  -webkit-font-smoothing:antialiased;
  transition:background var(--transition), color var(--transition);
  padding:16px;
}

.topbar{
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:12px;
  margin-bottom:16px;
}
.topbar h1{font-size:1.1rem;margin:0}
.topbar .controls{display:flex;gap:8px;align-items:center}

.container{max-width:720px;margin:0 auto}

.card{
  background:var(--card);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
  padding:20px;
  transition:transform var(--transition), box-shadow var(--transition), background var(--transition);
  overflow:hidden;
}
.fade-in{animation:fadeIn 400ms ease both}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

.category{font-size:0.8rem;color:var(--muted);margin-bottom:8px}
.question{font-size:1.25rem;margin:0 0 16px 0}

.options{display:flex;flex-direction:column;gap:12px}
.option{
  padding:14px 16px;
  border-radius:12px;
  border:1px solid rgba(0,0,0,0.06);
  background:linear-gradient(180deg,rgba(255,255,255,0.6),transparent);
  cursor:pointer;
  font-weight:600;
  transition:transform 160ms ease, box-shadow 160ms ease;
}
.option:hover{transform:translateY(-4px);box-shadow:0 8px 20px rgba(0,0,0,0.08)}
.option:active{transform:translateY(0) scale(.995)}

.btn{background:var(--accent);color:white;border:none}
.btn.small{padding:8px 12px;border-radius:10px}

.meta{display:flex;justify-content:space-between;align-items:center;margin-top:12px}
.link-btn{background:none;border:none;color:var(--accent);cursor:pointer;font-weight:600}

.percent-bar{display:flex;margin-top:12px;height:36px;border-radius:10px;overflow:hidden;background:rgba(0,0,0,0.04)}
.percent{display:flex;align-items:center;justify-content:center;font-weight:700;color:white;min-width:40px}
.percent.a{background:linear-gradient(90deg,var(--accent),#4f46e5)}
.percent.b{background:linear-gradient(90deg,#ef4444,#f97316)}

.controls-bottom{display:flex;gap:8px;justify-content:center;margin-top:16px}

.link{color:var(--muted);text-decoration:none;font-weight:600}

@media(min-width:700px){
  .options{flex-direction:row}
  .option{flex:1}
}

/* Smooth transitions for theme */
*{transition:background-color var(--transition), color var(--transition), border-color var(--transition), box-shadow var(--transition)}