@import "https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap";
:root{--background:#0f172a;--foreground:#f8fafc;--card-bg:#1e293bb3;--card-border:#ffffff1a;--primary:#3b82f6;--primary-hover:#2563eb;--success:#10b981;--error:#ef4444;--input-bg:#0f172a99;--input-border:#ffffff26}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--background);color:var(--foreground);background-image:radial-gradient(circle at 15%,#3b82f626,#0000 25%),radial-gradient(circle at 85% 30%,#10b9811a,#0000 25%);background-attachment:fixed;flex-direction:column;min-height:100vh;font-family:Inter,sans-serif;display:flex}.glass-card{background:var(--card-bg);-webkit-backdrop-filter:blur(12px);border:1px solid var(--card-border);border-radius:20px;box-shadow:0 8px 32px #0000004d}.input-field{background:var(--input-bg);border:1px solid var(--input-border);width:100%;color:var(--foreground);border-radius:8px;padding:12px 16px;font-family:inherit;font-size:1rem;transition:all .2s}.input-field:focus{border-color:var(--primary);outline:none;box-shadow:0 0 0 2px #3b82f633}.btn-primary{background:var(--primary);color:#fff;cursor:pointer;border:none;border-radius:8px;justify-content:center;align-items:center;width:100%;padding:12px 24px;font-family:inherit;font-size:1rem;font-weight:600;transition:all .2s;display:inline-flex}.btn-primary:hover{background:var(--primary-hover);transform:translateY(-1px)}.btn-primary:disabled{opacity:.7;cursor:not-allowed;transform:none}.difficulty-grid{grid-template-columns:repeat(auto-fill,minmax(130px,1fr));gap:12px;margin-top:12px;display:grid}.checkbox-label{background:var(--input-bg);border:1px solid var(--input-border);cursor:pointer;-webkit-user-select:none;user-select:none;border-radius:8px;align-items:center;padding:12px;transition:all .2s;display:flex}.checkbox-label:hover{background:#ffffff0d}.checkbox-label.selected{border-color:var(--primary);background:#3b82f61a}.checkbox-input{display:none}.container{width:100%;max-width:600px;margin:0 auto;padding:40px 20px}.text-center{text-align:center}.mb-2{margin-bottom:8px}.mb-4{margin-bottom:16px}.mb-6{margin-bottom:24px}.mb-8{margin-bottom:32px}.mt-4{margin-top:16px}.mt-8{margin-top:32px}.title{background:linear-gradient(135deg,#fff 0%,#cbd5e1 100%);-webkit-text-fill-color:transparent;-webkit-background-clip:text;margin-bottom:8px;font-size:2.25rem;font-weight:700}.subtitle{color:#94a3b8;font-size:1.1rem;line-height:1.6}.label{color:#cbd5e1;margin-bottom:8px;font-weight:500;display:block}.hint-text{color:#64748b;margin-top:4px;font-size:.85rem}.alert{border-radius:8px;margin-bottom:20px;padding:12px 16px;font-size:.95rem}.alert-success{color:#34d399;background:#10b98126;border:1px solid #10b9814d}.alert-error{color:#f87171;background:#ef444426;border:1px solid #ef44444d}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.animate-fade-in{animation:.5s forwards fadeIn}.delay-100{opacity:0;animation-delay:.1s}.delay-200{opacity:0;animation-delay:.2s}.delay-300{opacity:0;animation-delay:.3s}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.animate-spin{animation:1s linear infinite spin}