.center {text-align: center}
                .sr-only {
                    width: 1px;
                    height: 1px;
                    padding: 0;
                    margin: -1px;
                    overflow: hidden;
                    clip: rect(0,0,0,0);
                    border: 0;
                }
                .strong {font-weight: bold;}
                .italic {font-style: italic;}
                .serif {font-family: serif;}
                .sans {font-family: sans-serif;}
                .big {font-size: 1.5em;}
                .small {font-size: .75em;}
                .offset {
                    margin: 1em;
                    padding: 1.5em;
                    border: black 1px solid;
                }
                img {
                    padding: 0;
                    margin: 0;
                    max-width: 100%;
                    max-height: 100%;
                    column-count: 1;
                    break-inside: avoid;
                    oeb-column-number: 1;
                }