Neon.css

body{
    min-height: 100vh;
    background: #000;
    
    margin: 0px;
    padding: 0px;
    display: flex;
    justify-content: center;
    align-items: center; 
    font-size: 50px;
    font-family:monospace ;
}
.t1, .t2{
 
   text-decoration: none;
   position: relative;
   padding: 15px 30px;
   overflow: hidden;
   transition: 0.2s all; 
   color: #fff;
   text-transform: uppercase;
   letter-spacing: 4px;
}
.t1:hover{
    background: #c0262e;
    color: #000;
    box-shadow: 0px 0px 10px #c31432, 0px 0px 80px #c31432;
    transition-delay: 1s;
}
.t2 span, .t1 span{
    position: absolute;
    display:  inline-block;
}



.t1 span:nth-child(1){  
    top: 0px;
    left: -100%;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, #c31432);
}
.t1:hover span:nth-child(1){
    left: 100%;
    transition: 0.5s;
}

.t1 span:nth-child(3){
    bottom: 0px;
    right: -100%;
    width: 100%;
    height: 2px;
    background: linear-gradient(270deg, transparent, #c31432);
}
.t1:hover span:nth-child(3){
    right: 100%;
    transition: 0.5s;
    transition-delay: 0.5s;
}

.t1 span:nth-child(2){
    top: -100%;
    right: 0px;
    width: 2px;
    height: 100%;
    background: linear-gradient(180deg, transparent, #c31432);
}
.t1:hover span:nth-child(2){
    top: 100%;
    transition: 0.5s;
    transition-delay: 0.25s;
}

.t1 span:nth-child(4){
    bottom: -100%;
    left: 0px;
    width: 2px;
    height: 100%;
    background: linear-gradient(360deg, transparent, #c31432);
}
.t1:hover span:nth-child(4){
    bottom: 100%;
    transition: 0.5s;
    transition-delay: 0.75s;
}


.t2:hover{
    background: #38ef7d;
    color: #000;
    box-shadow: 0px 0px 10px #38ef7d, 0px 0px 40px #38ef7d, 0px 0px 80px #38ef7d;
    transition: 0.2s; ;
}


.t2 span:nth-child(1){
    top: 0px;
    left: -91%;
    width: 100%;
    height: 2px;
    background: #38ef7d;
}
.t2:hover span:nth-child(1){
    left:0%; 
    transition: 0.3s; 
}


.t2 span:nth-child(3){
    bottom: 0px;
    right: -91%;
    width: 100%;
    height: 2px;
    background: #38ef7d;
}
.t2:hover span:nth-child(3){
    right: 0%;
    transition: 0.3s;
}


.t2 span:nth-child(2){
    bottom: -70%;
    right: 0%;
    width: 2px;
    font-weight: 100;
    background: #38ef7d;
    height: 100%;
}
.t2:hover span:nth-child(2){
    bottom: 0%;
    transition: 0.3s;
}

.t2 span:nth-child(4){
    top: -70%;
    left: 0%;
    width: 2px;
    font-weight: 100;
    background: #38ef7d;
    height: 100%;
}
.t2:hover span:nth-child(4){
    top: 0%;
    transition: 0.3s;
}