mic.css

:root {
    --mic-color: #425066;
    --mic-size: 35px;
}
  
#audio-container {
    width: 100%;
    height: var(--mic-size);
    position: relative;
}

.fa {
    position: relative;
    top: 50%;
    transform: translateY(-50%);
}
  
.mic {
    color: #fff;
    text-align: center;
    font-size: 18px;
    white-space: nowrap;
    border: none;
    padding: 0;
    border-radius: 100%;
    width: var(--mic-size);
    height: var(--mic-size);
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    background: var(--mic-color);
    margin-left: auto;
    margin-right: auto;
}

.mic-overlay {
    z-index: 9;
    width: var(--mic-size);
    height: var(--mic-size);
    border: 2px solid var(--mic-color);
    border-radius: 100%;
    top: -2px;
    background: transparent;
    animation: pulsate infinite 1.5s;
}
  
@keyframes pulsate {
    0% {
    transform: scale(0.9, 0.9);
    opacity: 1;
    }
    100% {
    transform: scale(1.2, 1.2);
    opacity: 0;
    }
}