* { background: #fafaff; }
main {
    font-family: helvetica, sans-serif;
    font-size: 1.5rem;
    max-width: 60ch;
    margin: 0 auto;
}
footer { font-size: 1rem; }
h2 { font-size: 2rem; }
a, a:visited { color: #166491; }
a:active, a:focus, a:hover{ color: #2197db; }
p { display: block; }
.images { text-align: center; }
.images img {
    /* 30% max-width + 1% left margin + 1% right margin = 32%; 3 images fit with 1% space on each side */
    max-width: 30%;
    margin: 1%;
}
.images a:first-child img {
    max-width: 98%; /* 100% - 1% (left margin) - 1% (right margin)
    display: block;
}