styles.css

body {
    background: linear-gradient(#808080, #696969, #585858, #484848) no-repeat;
    background-size: cover;
}

h1 {
    text-align: center;
    color: #00ff7f;
    font-weight: bold;
    font-size: 38px;
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    text-decoration: underline;
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(3, 33%);
}

.grid-item {
    margin: 20px;
    padding: 2px;
    border: 4px solid #00FF7F;
    box-shadow: 3px 3px 7px #fff, -3px -3px 7px #fff;
    transition: 0.2s linear;
}

.grid-item:hover {
    transform: scale(1.1);
}

.grid {
    background: linear-gradient(#98FB98, #90EE90, #00FF7F);
    border: 5px solid #fff;
    box-shadow: inset 3px 3px 7px #00FF7F, inset -3px -3px 7px #00FF7F;
    padding: 6px;
    text-align: center;
    font-size: 18px;
    font-weight: 600;
    color: #000;
    line-height: 1.5em;
}

.grid div span {
    color: #000;
} 

.grid div a {
    color: #000;
}

@media screen and (max-width: 1100px) {
    .grid-container {
        grid-template-columns: repeat(2, 50%);
    }
}

@media screen and (max-width: 768px) {
    .grid-container {
        grid-template-columns: 100%;
    }
}