An example of how to create a lightning connection line using CSS language

<p class="cable">
    <span class="head"></span>
    <span class="body"></span>
</p>

body {
    margin: 0;
    height: 100vh;
    display: flex;
    align-items: center;
}

.cable {
    display: flex;
    align-items: center;
    font-size: 10px;
    margin-left: 5em;
}

.head {
    width: 8.5em;
    height: 8.5em;
    border-radius: 2em 0 0 2em;
}

.head {
    position: relative;
}

.head::before {
    content: '';
    position: absolute;
    width: 3em;
    height: 7.3em;
    top: calc((8.5em - 7.3em) / 2);
    left: 0.7em;
    border-radius: 1em;
    box-sizing: border-box;
}

.body {
    width: 15.5em;
    height: 11em;
    border-radius: 0.5em;
}

.body {
    position: relative;
    display: flex;
    align-items: center;
}

.body::before {
    content: '';
    position: absolute;
    width: 13.5em;
    height: 6em;
    left: 15.5em;
}

.body::after {
    content: '';
    position: absolute;
    width: 100vh;
    height: 3.9em;
    left: calc(15.5em + 13.5em);
}

body {
    overflow: hidden;
}

.body::after {
    background:
        linear-gradient(
            white,
            hsl(0, 0%, 96%) 5%,  
            hsl(0, 0%, 97%) 25%, 
            hsl(0, 0%, 95%) 40%, 
            hsl(0, 0%, 81%) 95%,
            white
        );
}

.body::before {
    background:
        linear-gradient(
            white,
            hsl(0, 0%, 96%) 5%,  
            hsl(0, 0%, 98%) 20%, 
            hsl(0, 0%, 95%) 50%, 
            hsl(0, 0%, 81%) 95%,
            white
        );
}

.body {
    background:linear-gradient(
        hsl(0, 0%, 91%),
        white 15%, 
        hsl(0, 0%, 93%) 50%, 
        hsl(0, 0%, 87%) 70%,
        hsl(0, 0%, 79%) 90%,
        hsl(0, 0%, 84%), 
        hsl(0, 0%, 86%)
    );
}

.head {
    background:
        linear-gradient(
            -45deg, 
            hsl(0, 0%, 75%),
            hsl(0, 0%, 79%),
            hsl(0, 0%, 78%),
            hsl(0, 0%, 87%) 80%
        );
}

.head::before {
    background-color: white;
}

.head::after {
    content: '';
    position: absolute;
    box-sizing: border-box;
    width: 2.2em;
    height: 0.4em;
    color: goldenrod;
    background-color: currentColor;
    border-radius: 0.5em;
    left: 1.1em;
    top: 1.2em;
    box-shadow: 
        0 0.8em 0,
        0 1.6em 0,
        0 2.4em 0,
        0 3.2em 0,
        0 4em 0,
        0 4.8em 0,
        0 5.6em 0;
}

.head {
    background:
        linear-gradient(
            90deg, 
            transparent 80%,
            rgba(0,0,0,12%)
        ),
        linear-gradient(
            -45deg, 
            hsl(0, 0%, 75%),
            hsl(0, 0%, 79%),
            hsl(0, 0%, 78%),
            hsl(0, 0%, 87%) 80%
        );
}

.body::before {
    background:
        linear-gradient(
            45deg, 
            rgba(0,0,0,4%) 10%,
            transparent 20%
        ),    
        linear-gradient(
            90deg, 
            rgba(0,0,0,4%), 
            transparent 10%
        ),
        linear-gradient(
            white,
            hsl(0, 0%, 96%) 5%,  
            hsl(0, 0%, 98%) 20%, 
            hsl(0, 0%, 95%) 50%, 
            hsl(0, 0%, 81%) 95%,
            white
        );
}

.body::after {
    background:
        linear-gradient(
            45deg, 
            rgba(0,0,0,4%),
            transparent 4%
        ),
        linear-gradient(
            90deg, 
            rgba(0,0,0,4%),
            transparent 2%
        ),
        linear-gradient(
            white,
            hsl(0, 0%, 96%) 5%,  
            hsl(0, 0%, 97%) 25%, 
            hsl(0, 0%, 95%) 40%, 
            hsl(0, 0%, 81%) 95%,
            white
        );
}

.cable {
    animation: show 5s linear infinite;
}

@keyframes show {
    0% {
        transform: translateX(100vw);
    }

    20%, 100% {
        transform: translateX(0);
    }
}