You can see a listing of how to implement various math functions, including min(x), for autocalc fields in the CSS Wizardry thread (although admittedly, it's not really CSS that's doing it). If you try to use an offline editor to make the character sheet, you'll be missing out on some things, most notably the sheet-2colrow and sheet-3colrow classes (and the sheet-col class which is intended for use inside the other two). Here's the CSS for those classes: .sheet-2colrow, .sheet-3colrow { display: block; clear: both; } .sheet-3colrow .sheet-col { width: calc(33% - 21px); margin-right: 30px; } .sheet-2colrow .sheet-col { width: calc(50% - 20px); margin-right: 30px; } .sheet-col { display: inline-block; vertical-align: top; } Also remember that autocalc fields won't work in an offline environment (they're calculated using some JavaScript), nor will repeating sections (manipulated with JavaScript), but those are both true of the preview pane as well. You'll also be missing out on some default styling which may slightly alter the look of your sheet offline as compared to online, and you won't have access to certain special fonts, such as the one used for the dice images which appear on roll buttons by default. It may also be worth pointing out, especially if you're copying code from my Exalted sheet, that when running on Roll20, all classes on your HTML elements are prefixed with "sheet-", and all selectors in your CSS are prefixed with ".charsheet ". So, if you write the following offline: <input type="number" name="attr_Reflexes" class="ability narrow" /> input.ability { font-style: italic; } .narrow { width: 10%; } It will look like you want it, but once you enter a campaign with it, you will effectively have: <div class="charsheet tab-pane"><input type="number" name="attr_Reflexes" class="sheet-ability sheet-narrow" /></div> .charsheet input.ability { font-style: italic; } .charsheet .narrow { width: 10%; } As you can see, the classes won't match up. If you remember to include sheet-* in your CSS you'll be fine (this is what I did on the Exalted sheet), but it may be simpler to just always remember to include sheet-* on all of your classes, even your HTML, and you'll have an easier time hunting down bugs.