glow_button.css

*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}

.glow-btn{
    display: flex;
    justify-content: center;
    align-items: center;
    /* min-height: 100vh; */
    /* background: #27282c; */
}

.glow-btn-child {
position: relative;
background: #444;
color: #fff;
text-decoration: none;
text-transform: uppercase;
font-size: 24px;
letter-spacing: 0.1em;
padding: 10px 30px;
transition:0.5s ;
}
.glow-btn-child:hover{
    letter-spacing: 0.2em;
    background: var(--clr);
    color: var(--clr);
    box-shadow: 0 0 35px var(--clr);
}
.glow-btn-child::before{
    content: '';
    position: absolute;
    inset: 2px;
    background: #27282c;
}

.glow-btn-child .glow-btn-subchild{
    position: relative;
    z-index: 1;
}

.glow-btn-child .i{
    position: absolute;
    inset: 0;
    display: block;
}

.glow-btn-child .i::before{
    content: '';
    position: absolute;
    top: -3.5px;
    left: 80%;
    width: 10px;
    height: 5px;
    border: 2px solid var(--clr);
    transform: translateX(-50%);
    background: #27282c;
    transition: 0.5s;
}

.glow-btn-child:hover .i::before{
    width: 20px;
    left: 20%;
}

.glow-btn-child .i::after{
    content: '';
    position: absolute;
    bottom: -3.5px;
    left: 20%;
    width: 10px;
    height: 5px;
    border: 2px solid var(--clr);
    transform: translateX(-50%);
    background: #27282c;
    transition: 0.5s;
}

.glow-btn-child:hover .i::after{
    width: 20px;
    left: 80%;
}