h1 span {
    color: #BD53ED;
    position: relative;
}

h1 span::before {
    content: "";
    height: 30px;
    width: 2px;
    position: absolute;
    top: 50%;
    right: -8px;
    background: #BD53ED;
    transform: translateY(-45%);
    animation: blink 0.7s infinite;
}

h1 span.stop-blinking::before {
    animation: none;
}

@keyframes blink {
    50% { opacity: 0 }
}