Fossil CSS Tips and Tricks

Many aspects of Fossil's appearance can be customized by customizing the site skin. This document details certain specific CSS tweaks which users have asked about via the forums.

This is a "living document" - please feel free to suggest additions via the Fossil forum.

This document is not an introduction to CSS - the web is full of tutorials on that topic. It covers only the specifics of customizing certain CSS-based behaviors in a Fossil UI. That said...

Is it Really !important?

By and large, CSS's !important qualifier is not needed when customizing Fossil's CSS. On occasion, however, particular styles may be set directly on DOM elements when Fossil generates its HTML, and such cases require the use of !important to override them.


Number of Columns in /dir View

The width of columns on the /dir page is calculated dynamically as the page is generated, to attempt to fit the widest name in a given directory. The number of columns is determined automatically by CSS. To modify the number of columns and/or the entry width:

div.columns {
  columns: WIDTH COLUMN_COUNT !important;
  /* Examples:
    columns: 20ex 3 !important
    columns: auto auto !important
/* The default rule uses div.columns, but it can also be selected using: */
div.columns.files { ... }

The !important qualifier is required here because the style values are dynamically calculated and applied when the HTML is emitted.

The file list itself can be further customized via:

div.columns > ul {
ul.browser {

Forum-specific CSS

Limiting Display Length of Long Posts

Excessively long posts can make scrolling through threads problematic, especially on mobile devices. The amount of a post which is visible can be configured using:

div.forumPostBody {
  max-height: 25em; /* change to the preferred maximum effective height */
  overflow: auto; /* tells the browser to add scrollbars as needed */