* {
    font-family: 'Barlow', Helvetica, Arial, sans-serif;
}

h2 {
    font-size: 1.6em;
    font-weight: 700;
}

p {
    font-size: 1.3em; 
}

a {
    color: black;
}

img {
    width: 100%;
}

header, section, aside, footer {
    box-sizing: border-box;
}

body {
    display: grid;
    grid-template-columns: 1fr;
    grid-gap: 10px;
    grid-template-areas: 
        'header'
        'section'
        'aside'
        'footer';
}

.gallery {
    display: grid;
    grid-template-columns: 1fr;
}

@media (min-width: 501px) and (max-width:900px){
    .gallery {
       grid-template-columns: repeat(2, 1fr);
    }
}
    
@media (min-width: 901px){
    body {
        grid-template-columns: repeat(4,1fr);
        grid-gap: 10px 10px;
        grid-template-areas: 
            'header header header header'
            'section section section aside'
            'footer footer footer footer';
    }
    
    .gallery {
        grid-template-columns: repeat(3, 1fr);
        padding-right: 10px;
    }
}
    
header {
    background-image: url(media/ada_banner.jpeg);
    width: 100%;
    background-size: cover;
    padding: 3em;
    font-size: 1em;
    grid-area: header;
}

ul {
   padding: 0; 
}

ul li {
    display: inline; 
    padding-right: 10px;
}

ul a {
    text-decoration: none;
    font-size: 1.3em;
}

section {
    grid-area: section;
}

.testimonials {
    display: flex;
    flex-flow: row;
    justify-content: space-between;
}

.testimonials a {
    width: 33%;
}

.testimonials figure {
    margin: 10px 10px;
}

.testimonials img {
    border-radius: 50%;
}

.testimonials figcaption {
    text-align: center;
}

aside {
    grid-area: aside;
}

aside img {
    padding-top: 1em;
}

footer {
    grid-area: footer;
}