@import url('https://fonts.googleapis.com/css?family=Poppins:200,300,400,500,600,700,800,900&display=swap');

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    /* overflow: hidden; */
}

ul {
    position: relative;
}

ul li {
    list-style: none;
    text-align: center;
}

ul li a {
    color: #333;
    text-decoration: none;
    font-size: 3em;
    padding: 5px 20px;
    display: inline-flex;
    font-weight: 700;
    transition: 0.5s;
}

ul:hover li a {
    color: #0002;
}

ul li:hover a {
    color: #000;
    background: rgba(255, 255, 255, 1);
}

ul li a:before {
    content: '';
    position: absolute;
    /* top: 50%;
    left: 50%; */
    transform: translate(-50%, -50%);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 5em;
    color: rgba(0, 0, 0, .1);
    border-radius: 50%;
    z-index: -1;
    opacity: 0;
    font-weight: 900;
    text-transform: uppercase;
    letter-spacing: 2000px;
    transition: letter-spacing 0.5s, left 0.5s;
}

ul li a:hover:before {
    content: attr(data-text);
    opacity: 1;
    left: 50%;
    letter-spacing: 10px;
    width: 300vh;
    height: 300vh;
}

ul li:nth-child(13n+1) a:before {
    background: #81ecec;
}

ul li:nth-child(13n+2) a:before {
    background: #ff7675;
}

ul li:nth-child(13n+3) a:before {
    background: #55efc4;
}

ul li:nth-child(13n+4) a:before {
    background: #a29bfe;
}

ul li:nth-child(13n+5) a:before {
    background: #fd79a8;
}

ul li:nth-child(13n+6) a:before {
    background: #ffeaa7;
}
ul li:nth-child(13n+7) a:before {
    background: #bcffa7;
}
ul li:nth-child(13n+8) a:before {
    background: #a7ffd9;
}
ul li:nth-child(13n+9) a:before {
    background: #a7c7ff;
}
ul li:nth-child(13n+10) a:before {
    background: #bda7ff;
}
ul li:nth-child(13n+11) a:before {
    background: #fea7ff;
}
ul li:nth-child(13n+12) a:before {
    background: #ffa7d0;
}
ul li:nth-child(13n+13) a:before {
    background: #ffa7a7;
}