.center {text-align: center}
            .sr-only {
                position: absolute;
                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;
            }