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

body {
    display: flex;
    justify-content: center;
    align-items: center;
    background: #0e1538;
    min-height: 100vh;
    gap: 200px;
}

 .box {
    position: relative;
    width: 300px;
    height: 400px;
    background: #0e1538;
 }

 .box::before {
    content : '';
    position: absolute;
    inset: -3px;
    background: linear-gradient(45deg, #00ccff, #0e1538, #0e1538, #d400d4);
    box-shadow: 0 0 0 20px #070c23;
    z-index: -1;    
 }

 .box::after {
    content : '';
    position: absolute;
    inset: -3px;
    background: linear-gradient(45deg, #00ccff, #0e1538, #0e1538, #d400d4);    
    z-index: -1;    
    filter: blur(20px);
 }

 .box:nth-child(2)::before, 
 .box:nth-child(2)::after  {
    background: linear-gradient(45deg, #ffeb3b, #0e1538, #0e1538, #00ff0a);
 }