:root{
  --bg:#f7f4ff;
  --card:#ffffff;
  --ink:#1f1f2e;
  --muted:#70708a;
  --primary:#7c3aed;
  --primary2:#f472b6;
  --soft:#ede9fe;
  --good:#10b981;
  --bad:#ef4444;
  --warn:#f59e0b;
  --line:#e8e4f5;
  --shadow:0 18px 55px rgba(64,44,120,.12);
  --radius:24px;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",Tahoma,sans-serif;
  color:var(--ink);
  background:
    radial-gradient(circle at 10% 5%, #ffe4f3 0 20%, transparent 35%),
    radial-gradient(circle at 90% 0%, #e0f2fe 0 18%, transparent 32%),
    var(--bg);
}
button,input,select{font:inherit}
button{cursor:pointer;border:0}
.app-shell{display:grid;grid-template-columns:290px 1fr;min-height:100vh}
.sidebar{
  position:sticky;top:0;height:100vh;
  padding:24px;
  background:rgba(255,255,255,.74);
  backdrop-filter:blur(14px);
  border-right:1px solid var(--line);
}
.brand{display:flex;gap:14px;align-items:center;margin-bottom:28px}
.brand-mark{
  width:58px;height:58px;border-radius:20px;
  display:grid;place-items:center;
  color:white;font-weight:900;font-size:22px;
  background:linear-gradient(135deg,var(--primary),var(--primary2));
  box-shadow:0 12px 30px rgba(124,58,237,.28);
}
.brand h1{font-size:20px;line-height:1.05;margin:0}
.brand p{font-size:13px;color:var(--muted);margin:5px 0 0}
.nav{display:grid;gap:10px}
.nav-btn{
  text-align:left;
  padding:14px 16px;border-radius:16px;
  color:#3f3f57;background:transparent;
}
.nav-btn:hover,.nav-btn.active{background:var(--soft);color:var(--primary);font-weight:800}
.profile-card{
  margin-top:24px;padding:16px;border-radius:20px;
  background:#fff;box-shadow:var(--shadow);
}
.profile-card label,.control-grid label{display:grid;gap:8px;font-size:13px;font-weight:800;color:#55516b}
input,select{
  width:100%;padding:13px 14px;border-radius:14px;
  border:1px solid var(--line);background:#fff;outline:none;
}
input:focus,select:focus{border-color:#b197ff;box-shadow:0 0 0 4px rgba(124,58,237,.1)}
.profile-card button{width:100%;margin-top:10px;padding:12px;border-radius:14px;background:var(--soft);color:var(--primary);font-weight:900}
.main{padding:28px;max-width:1180px;width:100%;margin:0 auto}
.topbar{display:flex;justify-content:space-between;gap:16px;align-items:center;margin-bottom:24px}
.eyebrow{margin:0;color:var(--primary);font-weight:900;font-size:13px}
.topbar h2{margin:4px 0 0;font-size:34px}
.top-stats{display:flex;gap:12px}
.top-stats div{
  min-width:88px;padding:14px;border-radius:18px;
  background:rgba(255,255,255,.78);box-shadow:var(--shadow);text-align:center;
}
.top-stats span{display:block;font-size:24px;font-weight:950}
.top-stats small{color:var(--muted)}
.view{display:none}.view.active{display:block}
.hero{
  display:grid;grid-template-columns:1fr 300px;gap:20px;
  padding:30px;border-radius:32px;
  color:white;
  background:linear-gradient(135deg,#7c3aed,#db2777);
  box-shadow:var(--shadow);
}
.hero h3{font-size:34px;margin:0 0 10px}
.hero p{font-size:17px;line-height:1.7;margin:0;opacity:.92}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}
.primary,.secondary,.danger{
  border-radius:16px;padding:13px 18px;font-weight:950;
}
.primary{background:linear-gradient(135deg,var(--primary),var(--primary2));color:white;box-shadow:0 12px 30px rgba(124,58,237,.25)}
.secondary{background:rgba(255,255,255,.18);color:white;border:1px solid rgba(255,255,255,.34)}
.danger{background:#fee2e2;color:#b91c1c;margin-top:12px}
.wide{width:100%;margin-top:16px}
.hero-card{background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.28);border-radius:24px;padding:20px;display:grid;align-content:center;gap:10px}
.hero-card strong{font-size:19px}.hero-card span,.hero-card small{opacity:.9}
.progress-line{height:12px;background:rgba(255,255,255,.22);border-radius:99px;overflow:hidden}
.progress-line i{display:block;height:100%;width:0%;background:#fff;border-radius:99px}
.section-title{margin:26px 0 14px}
.section-title h3{margin:0 0 4px;font-size:24px}
.section-title p{margin:0;color:var(--muted)}
.topic-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}
.topic-card,.panel,.question-card,.result-card{
  background:rgba(255,255,255,.86);
  border:1px solid var(--line);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
}
.topic-card{padding:18px;transition:.18s transform}
.topic-card:hover{transform:translateY(-3px)}
.topic-card .icon{width:48px;height:48px;border-radius:16px;display:grid;place-items:center;background:var(--soft);font-size:24px;margin-bottom:12px}
.topic-card h4{margin:0 0 8px;font-size:17px}
.topic-card p{margin:0;color:var(--muted);font-size:13px;line-height:1.5}
.topic-card button{margin-top:14px;padding:10px 12px;border-radius:12px;background:#f5f3ff;color:var(--primary);font-weight:900}
.panel{padding:22px;margin-bottom:18px}
.control-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:14px}
.split{display:flex;align-items:center;justify-content:space-between;gap:16px}
.split h3,.panel h3{margin-top:0}
.quiz-head{display:flex;justify-content:space-between;margin:20px 0 10px;color:var(--muted);font-weight:900}
.question-card{padding:24px}
#questionText{font-size:24px;line-height:1.55;font-weight:900;margin:0 0 16px}
.choice-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.choice{
  padding:16px;border-radius:18px;background:#f8f7ff;border:1px solid var(--line);text-align:left;font-weight:850;
}
.choice:hover{border-color:#b197ff;background:#f3efff}
.choice.correct{background:#dcfce7;border-color:#86efac;color:#166534}
.choice.wrong{background:#fee2e2;border-color:#fecaca;color:#991b1b}
.feedback{margin:16px 0 0;padding:16px;border-radius:18px;line-height:1.6}
.feedback.good{background:#dcfce7;color:#166534}
.feedback.bad{background:#fee2e2;color:#991b1b}
.hidden{display:none!important}
.stats-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px;margin-bottom:18px}
.stat-card{background:#fff;border:1px solid var(--line);border-radius:22px;padding:18px;box-shadow:var(--shadow)}
.stat-card span{display:block;font-size:28px;font-weight:950}
.stat-card small{color:var(--muted)}
.history{display:grid;gap:10px}
.history-row{display:flex;justify-content:space-between;gap:12px;padding:12px;border-radius:14px;background:#faf9ff}
.parent-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.parent-grid div{background:#faf9ff;border-radius:18px;padding:16px}
.parent-grid li{margin:8px 0;color:#4d4b62}
.toast{
  position:fixed;right:20px;bottom:20px;
  background:#111827;color:white;padding:13px 16px;border-radius:16px;
  box-shadow:var(--shadow);z-index:20;
}
@media(max-width:900px){
  .app-shell{grid-template-columns:1fr}
  .sidebar{position:relative;height:auto}
  .topbar,.hero,.split{display:grid}
  .hero{grid-template-columns:1fr}
  .topic-grid,.stats-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .control-grid,.parent-grid{grid-template-columns:1fr}
}
@media(max-width:560px){
  .main{padding:16px}
  .top-stats{display:grid;grid-template-columns:repeat(3,1fr);width:100%}
  .topic-grid,.choice-grid,.stats-grid{grid-template-columns:1fr}
  .topbar h2,.hero h3{font-size:28px}
}