Reduction of fonts in some regions in SharePoint (also the relationship between EM px)

After I installed Sharepoint, I found that some places have very small fonts and cannot be clearly understood, such as the places for viewing and searching notifications.
After checking, you can find that some styles use em to define the font size in the core.css file of sharepoint. for example:
. MS-formlabel {
Text-align: left;
Font-family:;
Font-size:. 75em;
Border-top: 1px solid # d8d8d8;
Padding-top: 3px;
Padding-Right: 8px;
Padding-bottom: 6px;
Color: #525252;
Font-weight: bold;
}

In this case, different effects may be displayed on different machines, because the size of EM changes.
Reference an article on the Internet Article Describe the relationship between EM PXIn this case, the two commonly used units in CSS that define the font size are em and PX.
Em is a relative logarithm. For example, 1.1em represents the width of 1.1 characters, and the width of this character is based on font - Size to initialize the size. At the same time, EM also inherits the features of the parent object, so 1.2em in different locations is not necessarily the same, but this article does not matter to me.
Px indicates the resolution of the current display device. Although the size difference still exists between different devices, it is more suitable for defining fonts.
This template does not specifically define the font size of the search part, so it uses the font of the parent object. - The size parameter is 12px. The font size defined by Internet Explorer and FF / Opera is different. By default, 1em looks larger than other browsers in IE, so you need to add the following definition in the body section:

Font - Size: 62.5 % ;
Font - Family: ' Lucida Grande ' , Verdana, Arial, sans - Serif;

The key is the first sentence, which makes the font size in IE look like: 1em = 10px, and FF / Opera is almost the same.

After knowing the problem, I just need to set the font to "medium" in IE, and everything will work.