@keyframes heartbeat {
    0% { transform: scale(1); }
    25% { transform: scale(1.1); }
    50% { transform: scale(1); }
    75% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

.heartbeat {
    animation: heartbeat 1s infinite;
}

.irregular {
    background-color: #FECACA;
    color: #991B1B;
}

.regular {
    background-color: #D1FAE5;
    color: #065F46;
}