body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.section {
    animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tab-btn.active {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.answer-btn:hover {
    transform: translateX(5px);
}

#flame {
    filter: drop-shadow(0 0 10px rgba(255, 165, 0, 0.8));
}

@keyframes flicker {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.8; }
}

#flame > div {
    animation: flicker 0.3s infinite;
}

#lab-simulation {
    min-height: 500px;
    position: relative;
}

#candle {
    z-index: 10;
}

#glass {
    z-index: 20;
}

.transition-all {
    transition: all 0.3s ease;
}