What is the CSS style of that HTML element ?: CSSPopup, an extension for firefox

Trying to find the CSS style of a HTML element is a common task for me and I often look in the <style/> of the pages to try to find what can be "this inspiring CSS". So, I've created CSSPopup, a small extension for firefox. This extension appends a new button in the contextual menu that will print all the CSS selectors of the element that was clicked. For example when I clicked on "Welcome to NCBI" at http://www.ncbi.nlm.nih.gov/, the result was:

h1 {
font-size:32px;
font-weight:bold;
line-height:36px;
margin-bottom:21.4333px;
margin-top:21.4333px;
padding-left:16px;
-moz-column-gap:32px;
}

div {
}

div {
}

div {
}

div {
margin-bottom:0px;
margin-left:0px;
margin-right:0px;
margin-top:0px;
}

body {
margin-bottom:8px;
margin-left:8px;
margin-right:8px;
margin-top:8px;
}

html {
background-attachment:scroll;
background-color:transparent;
background-image:none;
background-position:0% 0%;
background-repeat:repeat;
border-collapse:separate;
border-spacing:0px 0px;
bottom:auto;
caption-side:top;
clear:none;
clip:auto;
color:rgb(0, 0, 0);
content:none;
counter-increment:none;
counter-reset:none;
cursor:auto;
direction:ltr;
display:block;
empty-cells:show;
float:none;
font-family:serif;
font-size:16px;
font-size-adjust:none;
font-style:normal;
font-variant:normal;
font-weight:400;
height:auto;
ime-mode:auto;
left:auto;
letter-spacing:normal;
line-height:19px;
list-style-image:none;
list-style-position:outside;
list-style-type:disc;
margin-bottom:0px;
margin-left:0px;
margin-right:0px;
margin-top:0px;
marker-offset:auto;
max-height:none;
max-width:none;
min-height:0px;
min-width:0px;
opacity:1;
outline-color:rgb(0, 0, 0);
outline-offset:0px;
outline-style:none;
outline-width:0px;
overflow:visible;
overflow-x:visible;
overflow-y:visible;
padding-bottom:0px;
padding-left:0px;
padding-right:0px;
padding-top:0px;
page-break-after:auto;
page-break-before:auto;
pointer-events:visiblepainted;
position:static;
quotes:"“" "”" "‘" "’";
right:auto;
table-layout:auto;
text-align:start;
text-decoration:none;
text-indent:0px;
text-rendering:auto;
text-shadow:none;
text-transform:none;
top:auto;
unicode-bidi:normal;
vertical-align:baseline;
visibility:visible;
white-space:normal;
width:auto;
word-spacing:normal;
word-wrap:normal;
z-index:auto;
-moz-appearance:none;
-moz-background-clip:border;
-moz-background-inline-policy:continuous;
-moz-background-origin:padding;
-moz-binding:none;
-moz-border-bottom-colors:none;
-moz-border-left-colors:none;
-moz-border-right-colors:none;
-moz-border-top-colors:none;
-moz-border-image:none;
-moz-border-radius-bottomleft:0px;
-moz-border-radius-bottomright:0px;
-moz-border-radius-topleft:0px;
-moz-border-radius-topright:0px;
-moz-box-align:stretch;
-moz-box-direction:normal;
-moz-box-flex:0;
-moz-box-ordinal-group:1;
-moz-box-orient:horizontal;
-moz-box-pack:start;
-moz-box-shadow:none;
-moz-box-sizing:content-box;
-moz-column-count:auto;
-moz-column-gap:16px;
-moz-column-width:auto;
-moz-column-rule-width:0px;
-moz-column-rule-style:none;
-moz-column-rule-color:rgb(0, 0, 0);
-moz-float-edge:content-box;
-moz-force-broken-image-icon:0;
-moz-image-region:auto;
-moz-outline-color:rgb(0, 0, 0);
-moz-outline-offset:0px;
-moz-outline-radius-bottomleft:0px;
-moz-outline-radius-bottomright:0px;
-moz-outline-radius-topleft:0px;
-moz-outline-radius-topright:0px;
-moz-outline-style:none;
-moz-outline-width:0px;
-moz-stack-sizing:stretch-to-fit;
-moz-transform:none;
-moz-transform-origin:50% 50%;
-moz-user-focus:none;
-moz-user-input:auto;
-moz-user-modify:read-only;
-moz-user-select:auto;
-moz-appearance:none;
-moz-user-select:auto;
}

The extension can be downloaded at http://code.google.com/p/lindenb/downloads/list and the source code is available at http://code.google.com/p/lindenb/source/browse/trunk/proj/tinyxul/csspopup/.

That's it,
Pierre