Hi, Browsing the (very pretty) new documentation with Firefox, I noticed that selecting text was slow, especially on large pages. For example, on the module index page, it could take up to 1 second until the blue selection background would appear after I had selected some text with the mouse. I figured it could have something to do with the style sheet and by commenting out various parts of default.css, I narrowed the cause down to this: *:hover > a.headerlink, *:hover > a.headerlink, *:hover > a.headerlink, *:hover > a.headerlink, *:hover > a.headerlink, *:hover > a.headerlink { visibility: visible; } Most likely the problem is with the *:hover quantifier. When the mouse hovers over any element, Firefox has to check if there's a a.headerlink in the element. After changing *:hover to the specific elements h1-h6 and dt (are these all?), text selection is as smooth as it should be and maybe even overall display speed is better. Attached is a patch for this, which also removes some (unnecessary?) duplication. What do you think, could you commit the patch? Robin Index: sphinx/style/default.css =================================================================== --- sphinx/style/default.css (revision 57882) +++ sphinx/style/default.css (working copy) @@ -529,11 +529,6 @@ div.body h5 { font-size: 110%; } div.body h6 { font-size: 100%; } -a.headerlink, -a.headerlink, -a.headerlink, -a.headerlink, -a.headerlink, a.headerlink { color: #c60f0f; font-size: 0.8em; @@ -542,20 +537,16 @@ visibility: hidden; } -*:hover > a.headerlink, -*:hover > a.headerlink, -*:hover > a.headerlink, -*:hover > a.headerlink, -*:hover > a.headerlink, -*:hover > a.headerlink { +h1:hover > a.headerlink, +h2:hover > a.headerlink, +h3:hover > a.headerlink, +h4:hover > a.headerlink, +h5:hover > a.headerlink, +h6:hover > a.headerlink, +dt:hover > a.headerlink { visibility: visible; } -a.headerlink:hover, -a.headerlink:hover, -a.headerlink:hover, -a.headerlink:hover, -a.headerlink:hover, a.headerlink:hover { background-color: #c60f0f; color: white;