:root{--b:#2563eb;--p:#7c3aed;--c:#0891b2;--g:#16a34a;--r:#dc2626;--ink:#172033;--mut:#64748b}
*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Arial,sans-serif;color:var(--ink);background:linear-gradient(180deg,#e0f2fe,#fff 46%,#f5f3ff);line-height:1.55}
nav{position:sticky;top:0;z-index:30;background:#fff;box-shadow:0 2px 14px #0001;padding:9px 5%;display:flex;align-items:center;gap:18px;flex-wrap:wrap}.logo{display:flex;align-items:center;gap:9px;text-decoration:none;font-weight:950;color:#1d4ed8}.logoMark{width:40px;height:40px;border-radius:12px;background:linear-gradient(135deg,var(--b),var(--p));color:#fff;display:grid;place-items:center;box-shadow:0 5px 12px #2563eb44}.navlink{font-weight:900;color:#334155;text-decoration:none}
header{position:relative;overflow:hidden;text-align:center;color:#fff;padding:28px 15px 44px;background:linear-gradient(135deg,#1d4ed8,#7c3aed,#0891b2)}header h1{font-size:clamp(1.55rem,5vw,3rem);margin:8px 0 4px}.symbols{font-size:2.6rem;letter-spacing:4px;animation:bob 2.8s infinite}@keyframes bob{50%{transform:translateY(-9px)}}.float{position:absolute;font-size:2rem;animation:float 5s infinite}.f1{left:4%;top:18%}.f2{right:5%;top:15%}.f3{left:14%;bottom:4%}.f4{right:15%;bottom:0}@keyframes float{50%{transform:translateY(-18px) rotate(8deg)}}
main{max-width:1150px;margin:auto;padding:14px}.panel,.q{background:#fff;border:1px solid #dbeafe;border-radius:20px;box-shadow:0 8px 28px #1e3a8a12}.controls{margin-top:-20px;position:relative;display:grid;grid-template-columns:repeat(5,1fr);gap:10px;padding:16px}label{font-size:.82rem;font-weight:900;color:var(--mut)}select,input{width:100%;min-height:44px;padding:10px;border:2px solid #dbe4ef;border-radius:12px;background:#fff;font:inherit}button{border:0;border-radius:12px;padding:11px 14px;font:inherit;font-weight:850;cursor:pointer;transition:.15s}button:hover{transform:translateY(-2px);box-shadow:0 5px 14px #0002}.primary{background:linear-gradient(135deg,var(--b),var(--p));color:#fff}.secondary{background:#e0edff;color:#164e9c}
.status{padding:14px;margin:15px 0}.notice{background:#fff7ed;border-left:5px solid #f97316;padding:10px 13px;border-radius:10px;margin:12px 0;font-weight:750}.stats{display:flex;gap:8px;flex-wrap:wrap}.badge{padding:6px 11px;background:#f1f5f9;border-radius:999px;font-weight:850}.bar{height:14px;background:#dbeafe;border-radius:99px;overflow:hidden;margin:9px 0}.fill{height:100%;width:0;background:linear-gradient(90deg,#22c55e,#06b6d4,#8b5cf6);transition:.35s}
#worksheet{display:grid;gap:13px}.q{padding:17px;position:relative}.head{display:flex;gap:11px}.num{min-width:38px;height:38px;border-radius:50%;display:grid;place-items:center;background:#dbeafe;color:#1d4ed8;font-weight:900}.question{font-weight:850;font-size:1.05rem}.tag{font-size:.72rem;color:var(--mut)}.options{display:grid;grid-template-columns:1fr 1fr;gap:9px;margin:12px 0}.opt{background:#f8fafc;border:2px solid #dbe4ef;text-align:left}.opt.selected{background:#dbeafe;border-color:#2563eb}.feedback{min-height:25px;font-weight:850}.q.correct{border:2px solid #86efac;animation:correct .45s}.q.wrong{border:2px solid #fca5a5;animation:shake .35s}@keyframes correct{50%{transform:scale(1.012)}}@keyframes shake{25%{transform:translateX(-6px)}75%{transform:translateX(6px)}}.actions{display:flex;gap:8px;flex-wrap:wrap}.show{display:none;background:#dcfce7;color:#166534}.result{display:none;text-align:center;padding:25px;margin:18px 0;background:#ecfdf5;border:2px solid #86efac}.result.show{display:block}.article{padding:24px;margin:22px 0}.article h2{color:#1d4ed8}.article h3{color:#7c3aed}.formula{background:#eff6ff;border-left:5px solid #2563eb;padding:12px 15px;border-radius:10px;font-weight:850}.chip{display:inline-block;background:#ede9fe;color:#5b21b6;border-radius:999px;padding:4px 9px;margin:3px;font-weight:800}footer{text-align:center;padding:28px;color:var(--mut)}
@media(max-width:850px){.controls{grid-template-columns:1fr 1fr}.options{grid-template-columns:1fr}}@media(max-width:520px){nav{padding:9px 4%}.controls{grid-template-columns:1fr}.actions button{flex:1}.q{padding:14px}.symbols{font-size:2.05rem}}@media print{nav,header,.controls,.status,.result,footer,.article{display:none!important}.q{box-shadow:none;break-inside:avoid}}