body {
    margin: 0; padding: 0;
    background-color: #03030a;
    color: #e2e8f0;
    font-family: 'Space Grotesk', sans-serif;
    overflow-x: hidden;
    min-height: 100vh;
}
#star-canvas {
    position: fixed; top: 0; left: 0; width: 100vw; height: 100vh;
    z-index: -1; pointer-events: none;
}
.glass-panel {
    background: rgba(15, 20, 35, 0.4);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(100, 200, 255, 0.1);
    border-radius: 1rem;
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.5), inset 0 0 20px rgba(100, 200, 255, 0.05);
}
.quantum-btn {
    background: linear-gradient(135deg, #2b00ff 0%, #00d4ff 100%);
    color: white; transition: all 0.3s ease; position: relative; overflow: hidden; border: none;
}
.quantum-btn::before {
    content: ''; position: absolute; top: 0; left: -100%; width: 100%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: all 0.4s ease;
}
.quantum-btn:hover::before { left: 100%; }
.quantum-btn:hover { box-shadow: 0 0 20px rgba(0, 212, 255, 0.6); transform: translateY(-2px); }
.nav-link { transition: all 0.2s ease; position: relative; }
.nav-link::after {
    content: ''; position: absolute; width: 0; height: 2px;
    bottom: -4px; left: 0; background: #00d4ff; transition: width 0.3s ease;
}
.nav-link:hover::after, .nav-link.active::after { width: 100%; }
.nav-link.active { color: #00d4ff; text-shadow: 0 0 10px rgba(0, 212, 255, 0.5); }

/* Custom Radio Button */
input[type="radio"] {
    appearance: none; background-color: rgba(255,255,255,0.1); margin: 0;
    width: 1.15em; height: 1.15em; border: 2px solid #00d4ff; border-radius: 50%;
    display: grid; place-content: center; cursor: pointer;
}
input[type="radio"]::before {
    content: ""; width: 0.65em; height: 0.65em; border-radius: 50%;
    transform: scale(0); transition: 120ms transform ease-in-out; box-shadow: inset 1em 1em #00d4ff;
}
input[type="radio"]:checked::before { transform: scale(1); }
.radio-label {
    display: flex; align-items: center; gap: 0.75rem; padding: 0.75rem 1rem;
    border-radius: 0.5rem; border: 1px solid rgba(255,255,255,0.05); background: rgba(0,0,0,0.2);
    cursor: pointer; transition: all 0.2s;
}
.radio-label:hover { background: rgba(0, 212, 255, 0.1); border-color: rgba(0, 212, 255, 0.3); }

/* Custom Pop-up Animations */
.alert-fade-in { animation: fadeIn 0.2s ease-out forwards; }
.alert-scale-up { animation: scaleUp 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards; }

@keyframes fadeIn {
    from { opacity: 0; backdrop-filter: blur(0px); }
    to { opacity: 1; backdrop-filter: blur(4px); }
}
@keyframes scaleUp {
    from { opacity: 0; transform: scale(0.9) translateY(10px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}