body {
    margin: 40px;
}

p,
q,
td,
th {
    font-size: 1.25rem; /* Usually about 16px */
}
ul li,
ol li {
    font-size: 1.25rem;
    margin-bottom: 10px;
}
h1 {
    font-size: 2.25rem;
}
h2 {
    font-size: 2rem;
}
h3 {
    font-size: 1.75rem;
}
.copyright {
    font-size: 0.8em; /* smaller */
    color: #666; /* soft grey */
    text-align: center; /* centred looks gentler */
    margin-top: 2em; /* breathing room */
    margin-bottom: 1em; /* above navbar gap */
}
.orig-img,
.orig-img-3p,
.orig-video {
    display: block;
    text-align: center;
    margin: 0.5em auto;
    padding: 0.25em 0;
    font-size: 0.9em;
    color: #444;
}

@media (max-width: 600px) {
    p,
    q,
    td,
    th {
        font-size: 2.25rem;
    }
    ul li,
    ol li {
        font-size: 2.25rem;
        margin-bottom: 10px;
    }
    h1 {
        font-size: 3.25rem;
    }

    h2 {
        font-size: 3rem;
    }

    h3 {
        font-size: 2.75rem;
    }
    .copyright {
        font-size: 1.8em; /* smaller */
        color: #666; /* soft grey */
        text-align: center; /* centred looks gentler */
        margin-top: 2em; /* breathing room */
        margin-bottom: 1em; /* above navbar gap */
    }

    .orig-img,
    .orig-img-3p,
    .orig-video {
        display: block;
        text-align: center;
        margin: 0.5em auto;
        padding: 0.25em 0;
        font-size: 1.9em;
        color: #444;
    }
}

nav {
    background-color: aquamarine;
}
.brief {
    margin-left: 50px;
}
.grid {
    display: grid;
    grid-template-columns: 1fr 1fr; /* two equal columns */
    gap: 10px;
    background-color: #2196f3;
    padding: 10px;
}

.grid > img,
.grid > video {
    width: 100%;
    height: auto; /* let height adjust naturally */
    object-fit: contain; /* show the whole image/video */
    background-color: rgba(255, 255, 255, 0.8);
    padding: 10px;
}

/* source:  https://www.w3schools.com/howto/howto_css_image_gallery.asp */

div.gallery {
    border: 1px solid #ccc;
}

div.gallery:hover {
    border: 1px solid #777;
}

div.gallery img {
    width: 100%;
    height: auto;
}

div.desc {
    padding: 15px;
    text-align: center;
}

* {
    box-sizing: border-box;
}

.responsive {
    padding: 0 6px;
    float: left;
    width: 24.99999%;
}

@media only screen and (max-width: 700px) {
    .responsive {
        width: 49.99999%;
        margin: 6px 0;
    }
}

@media only screen and (max-width: 500px) {
    .responsive {
        width: 100%;
    }
}

.clearfix:after {
    content: "";
    display: table;
    clear: both;
}