trying to find the CSS file used in a website and .axd

Hi i am a new programer for a project that is already running, and they told me to do some changes in the text but when i try to inspect the site to see which CSS file is it using i dont seem to find it, because its calling or making a ref to a .axd and when i search it on the directory its not there the file

and example next

<style></style>
<link rel="stylesheet" type="text/css" href="/DXR.axd?r=2_1">
<link rel="stylesheet" type="text/css" href="/DXR.axd?r=1_18">
<link rel="stylesheet" type="text/css" href="/DXR.axd?r=2_0">
<link rel="stylesheet" type="text/css" href="/DXR.axd?r=1_17">

Also i found out that the values that i need to change are in this part of the code but it dosent says where in the file directory is it

<style type="text/css">
.csC5EFD183 {color:#000000;background-color:#F5F5F5;border-left-style: 
none;border-top-style: none;border-right-style: none;border-bottom-style: 
none;font-family:Arial; font-size:9pt; font-weight:bold; font-style:normal; 
}
.cs830A0321 {color:#000000;background-color:transparent;border-left-style: 
none;border-top-style: none;border-right-style: none;border-bottom-style: 
none;font-family:Arial; font-size:11pt; font-weight:normal; font- 
style:normal; padding-left:2px;padding-right:2px;}
 .cs7F90395C {color:#000000;background-color:transparent;border-left-style: 
 none;border-top-style: none;border-right-style: none;border-bottom-style: 
 none;font-family:Arial; font-size:9pt; font-weight:normal; font- 
 style:normal; padding-left:2px;padding-right:2px;}
.cs779A3ACC {color:#800000;background-color:#FFFFFF;border-left-style: 
none;border-top-style: none;border-right-style: none;border-bottom-style: 
none;font-family:Arial; font-size:9pt; font-weight:bold; font-style:normal; 
}
.csAC6A4475 {height:0px;width:0px;overflow:hidden;font-size:0px;line- 
height:0px;}
 </style>