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

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: lightcyan;
}

ul {
    position: relative;
    display: flex;
}

ul li {
    position: relative;
    width: 360px;
    height: 360px;
    box-shadow: 0 15px 35px rgba(0,0,0,.1);
    display: flex;
    justify-content: center;
    align-items: center;
    background: #fff;
    cursor: pointer;
}

ul li .fa-lemon {
    font-size: 12em;
    -webkit-text-stroke: 2px var(--clr);
    color: transparent;
}

ul li::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    overflow: hidden;
    height: 0;
    border-bottom: 4px solid var(--clr);
    transition: 0.5s ease-in-out;
    font-family: fontAwesome;
    text-align: center;
    line-height: 360px;
    font-size: 12em;
    color: yellowgreen;
}

ul li:hover::before {
    height: 100%;
}

ul li:nth-child(1):before {
    content: '\f094';
}