:root{
  --primary:#4e73df;
  --accent:#1cc88a;
  --danger:#e74a3b;
  --bg:#f4f6f9;
  --card:#ffffff;
  --muted:#6b7280;
  --border:#e6e9ef;
  --text:#222;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family:Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial;
  background:var(--bg);
  color:var(--text);
  padding:28px;
  max-width:920px;
  margin-inline:auto;
}

/* Header */
.app-header{
  background:linear-gradient(45deg,var(--primary),var(--accent));
  color:#fff;
  padding:18px;
  border-radius:12px;
  box-shadow:0 10px 24px rgba(2,6,23,0.12);
  text-align:center;
}
.app-header h1{margin:0;font-size:24px}
.subtitle{margin:6px 0 0;opacity:.95;font-weight:600}

/* Card */
.card{
  background:var(--card);
  border:1px solid var(--border);
  border-radius:12px;
  padding:16px;
  margin-top:18px;
  box-shadow:0 8px 18px rgba(15,23,42,0.06);
}
.hidden{display:none}

/* Forms */
.form-row{margin:10px 0}
label{display:block;font-weight:700;margin-bottom:6px;font-size:14px}
input[type="text"],input[type="email"],input[type="password"]{
  width:100%;
  padding:10px 12px;
  border-radius:8px;
  border:1px solid #ccd6e6;
  background:#fff;
  font-size:15px;
  transition:box-shadow .15s, border-color .15s;
}
input:focus{outline:none;border-color:var(--primary);box-shadow:0 6px 20px rgba(78,115,223,0.06)}

/* Buttons */
.btn, .btn-outline, .btn-danger {
  padding:10px 16px;
  border-radius:8px;
  font-weight:700;
  cursor:pointer;
  border:none;
  transition:transform .08s ease, opacity .12s ease;
}
.btn{background:var(--primary); color:#fff}
.btn:hover{transform:translateY(-2px);opacity:.98}
.btn-outline{background:#fff;border:2px solid var(--primary);color:var(--primary)}
.btn-outline:hover{background:var(--primary);color:#fff}
.btn-danger{background:var(--danger);color:#fff}

/* Quiz layout */
.quiz-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px}
.timer{font-weight:800;color:var(--danger)}
.question{font-size:18px;margin:8px 0}
.options{display:grid;gap:10px}
.option{
  display:flex;align-items:center;gap:12px;padding:12px;border-radius:10px;border:1px solid var(--border);
  background:#fbfdff;cursor:pointer;transition:transform .08s ease, box-shadow .12s ease, border-color .12s ease;
}
.option:hover{transform:translateY(-2px);box-shadow:0 8px 18px rgba(78,115,223,0.06)}
.option input[type="radio"]{transform:scale(1.2)}
.actions{margin-top:14px;display:flex;gap:10px;flex-wrap:wrap}

/* Results */
.result-line{font-size:18px;font-weight:800;margin:8px 0}
.past-results ul{list-style:none;margin:10px 0;padding:0}
.past-results li{background:#fbfbfc;border:1px solid var(--border);padding:10px;border-radius:8px;margin:6px 0}

/* Footer */
.footer{text-align:center;margin-top:18px;color:var(--muted)}
.muted{color:var(--muted)}
a{color:var(--primary);font-weight:700;text-decoration:none}
a:hover{text-decoration:underline}

/* Responsive */
@media (max-width:520px){
  .app-header h1{font-size:20px}
  .question{font-size:16px}
}