AutoHide for Editing Mode on Moodle 2.X (Mark Ward & Mark Johnson Combined CSS). Why? Well, now the "Bordered static marching ants" and "fading icons" effect by Mark Ward are combined with Mark Johnson's section-level controls on topics/weeks formats, so

autohide.css

/** To hide the icons we are using opacity as display:none makes
the buttons inaccessible. 

FILTER attributes should apply to IE so long as the strict 
doctype is served. Use Filter: none on clear to protect PNG alphas.

Tweak the top opacity values to get "ghost" icons rather than hiding them**/
.block .header .commands a img,
.path-course-view .section .content li .commands a img,
.path-course-view .section .content .summary a img.icon.edit{
	opacity: 0.01;	
	filter: alpha(opacity=1);
	-o-transition: opacity 0.5s linear 0.3s;
	-moz-transition: opacity 0.5s linear 0.3s;
	-webkit-transition: opacity 0.5s linear 0.3s;
	transition: opacity 0.5s linear 0.3s;
}

.path-course-view .section .left.side a img,
.path-course-view .section .right.side a img,
.path-course-view .section .right.side div img
{
    opacity: 0.01; 
    filter: alpha(opacity=1);
}

.path-course-view .section:hover .right.side img,
.path-course-view .section:hover .left.side img,
.path-course-view .section .right.side a:focus img,
.path-course-view .section .left.side a:focus img,
.ie.path-course-view .section .right.side a:active img,
.ie.path-course-view .section .left.side a:active img
{
    opacity:1;
    filter: none;
}
.block:hover .header .commands a img,
.block .header .commands a:focus img,
.ie .block .header .commands a:active img,
.path-course-view .section .content li:hover .commands a img,
.path-course-view .section .content li .commands a:focus img,
.ie.path-course-view .section .content li .commands a:active img,
.path-course-view .section:hover .content .summary a img.icon.edit,
.path-course-view .section .content .summary a:focus img.icon.edit,
.ie.path-course-view .section .content .summary a:active img.icon.edit{
	opacity:1;
	filter: none;
	-o-transition: opacity 0.3s;
	-moz-transition: opacity 0.3s;
	-webkit-transition: opacity 0.3s;
	transition: opacity 0.3s;
}

/** some feedback to tell user we are in editing mode **/
.editing.path-course-view div.content{
	border: 2px #caa dotted;
	box-shadow: #caa 0px 0px 10px;
}

.path-course-view .section .content .section_add_menus{
	background-color: #caa;
	padding: .1em 0;
}

Ah! Does hiding the section-level controls work ok in Internet Explorer? When I tried it the drop down lists disappeared as soon as I moved the cursor away from the launch point because IE didn't recognise I was still on the element.