refreshment.css

@import url('https://fonts.googleapis.com/css2?family=Nunito:wght@200;300;400;600;700&display=swap');
:root {
    --red: #ff3838;
}

*{
    font-family: 'Nunito', sans-serif;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    outline: none;
    border: none;
    text-decoration: none;
    text-transform: capitalize;
    transition: all .2s linear;
}

html {
    font-size: 62.5%;
    overflow-x: hidden;
    scroll-behavior: smooth;
    scroll-padding-top: 6rem;
}

body {
    background: #f7f7f7;
}

section {
    padding: 2rem 9%;
}

.heading {
    text-align: center;
    font-size: 3.5rem;
    padding: 1rem;
    color: #666;
}

.heading span {
    color: var(--red);
}

.gallery .box-container {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    grid-gap: 1.5rem;
}

.gallery .box-container .box {
    height: 25rem;
    border: 1rem solid #fff;
    box-shadow: 0 .5rem 1rem rgba(0, 0, 0, .1);
    border-radius: .5rem;
}

.gallery .box-container .box img {
    height: 100%;
    width: 100%;
    object-fit: cover;
}

/* media queries  */

@media(max-width:991px) {
    html {
        font-size: 55%;
    }
    header {
        padding: 2rem;
    }
    section {
        padding: 2rem;
    }
}

@media(max-width:450px) {
    html {
        font-size: 50%;
    }
    .gallery .box-container {
        display: grid;
        grid-template-columns: 1fr 1fr;
        grid-gap: 1.5rem;
    }
}