Custom themes - Atavist/developer Wiki

Making your own Atavist theme is simple. It’s mostly a matter of defining a few variables, and maybe a mixin or two, in Sass. If you’d like your theme to use custom fonts, you can include them via a third-party service or as uploaded font files.

Why use a CSS preprocessor? For one thing, it enables expressive but DRY theming, allowing for a single aesthetic decision — say, a color selection — to be made once, in a variable, and propagated throughout a stylesheet where applicable. For another, it allows for themes to be abstracted from template markup, which will evolve over time.

Why use Sass? We like it.

Custom themes can be developed from within Atavist by users at the Business tier or higher. If you don’t have an Atavist account, go get one. Once signed in, click “Develop” from the top menu and “Theme” from the left sidebar. You’ll be looking at the theme-building interface.

Defining theme styles

Rule #1: Don’t write raw CSS. Don’t write raw CSS. You define styles with theme variables and mixins.

Rule #2: You don’t need to redefine every theme variable and mixin that exist. In fact, you really shouldn’t. You can make a distinct theme with just a handful of variables.

Theme variables

For the most part, a theme will consist of Sass variable definitions, like this:

$primaryBackgroundColor: white;

Variables exist for both high- and low-level theming decisions. If your theme specifies, for example, only a $primaryBackgroundColor and $primaryTextColor, other color values — the color of icons, the color of navigational elements, the color of hyperlink underlines — will be inferred. If you’d like to dig deeper, you can do so by defining more specific variables, like $linkUnderlineColor-h2 (the color of link underlines within h2 elements).

To see what variables exist, browse our theme variable and mixin reference doc.

Theme mixins

For a few types of elements, styles can be defined as mixins, or groups of styles. In many cases, these mixins are composed, at least in part, of style properties defined line-by-line as Sass variables. This allows theme creators to define styles either piecemeal or holistically. Here, for example, is how the atavist-sidebar mixin is compiled:

@mixin atavist-sidebar {
    @if mixin-exists(atavist-sidebar-theme) {
    	@include atavist-sidebar-theme;
    } @else {
		.atavist-sidebar {
			font-size: $sidebarBlockFontSize;
			line-height: $sidebarBlockLineHeight;
			p, pre, article & ul, article & ol, blockquote {
				font-family: $sidebarBlockBodyTextFontFamily;
				font-size: $sidebarBlockBodyTextFontSize;				
			.template-setting-paragraph-spacing-Spaces & p:not(.atavist-caption), .template-setting-paragraph-spacing-Spaces & pre {
				margin-top: $sidebarBlockParagraphTopMargin;

If you, as a theme creator, would like to change nothing but the Sidebar block’s font size, there’s a variable for that you can define: $sidebarBlockFontSize. If, on the other hand, you’d like to redefine styles for the Sidebar block holistically, you can redefine the mixin entirely. To do that, add a mixin to your theme Sass. To name a theme-specific mixin, add -theme to the mixin’s name, like this:

@mixin atavist-sidebar-theme {
	font-size: 1em;
	line-height: 1.2;
	color: #333;

To see what mixins exist, browse our theme variable and mixin reference doc.

Adding CSS overrides.

You shouldn’t use raw CSS in your themes, but if you absolutely must, you can declare styles inside a special mixin: theme-css-overrides. These styles will be appended to the end of the reader-facing stylesheet.

@mixin theme-css-overrides {	
	/* CSS overrides here */

Adding fonts to your theme

You can add fonts to your theme from within the Atavist theme-building interface.

External fonts

You can add fonts from third-party services to your theme. Select a font provider and, depending on the provider, add the requested path or service-specific ID.

Uploaded fonts

If you have webfont files on hand, you can upload the assets and use the fonts in your theme. Upload the webfont files individually (must be WOFF, TTF, SVG, or EOT files), and give them a font family name, like Avenir or "Helvetica Neue". Use the same name for all font files associated with a given font family. Then, in your custom theme Sass, use the font family names just as you would normally in CSS, e.g. $primaryFontFamily: "My Custom Font", Helvetica, sans-serif;.

Custom theme field definitions

A custom theme, like Atavist’s own themes, can present options to the user that are configurable on a project basis. Because these options set Sass variables defined in your theme, they can be used in practice to configure any aspect of a project a theme touches: colors, type styles, spacing, and more.

Custom theme fields are defined with JSON, like other fields (for a reference of field types and definition syntax, see Field types). With custom theme field definitions, there are a few things to keep in mind:

  1. The top-level property name of a custom field should match a Sass variable name defined in your theme, without the dollar sign ($). If you define a value for $primaryBackgroundColor in your theme, the property in your field definition should be primaryBackgroundColor.

  2. Within each field definition object, you must include a context property with the value sass.

  3. When you define a field, the corresponding Sass variable in your theme must use the !default flag. This ensures the Sass will be compiled correctly.


To allow those using your theme to choose a background color for each of their projects, you might include field definition JSON that looks like this:

	"primaryBackgroundColor": {
		"type": "colorpicker",
		"label": "Background color",
		"default": "#ffffff",
		"context": "sass"

The corresponding bit from your theme’s Sass might look like this:

$primaryBackgroundColor: #ffffff !default;