Firebug, Aptana Studio 3, FileZilla & style.css

I am new to web development, so I hope my question isn’t too silly.

I have downloaded Firebug to help make changes to my site. I have also downloaded Aptana Studio 3. I also use FileZilla. I am trying to change the height of my header picture on my home page. When I go to my site and inspect element using firebug, the code that seems to apply to the height of my picture is:

.header-image {
    height: 360px;
}
.header-image {
    height: 280px;
}
.header-image {
   height: 200px;

   position: relative;
}

Although “height: 280px” and “height: 200px” are both crossed out with a line through their centers.

This leads me to believe that the number I need to change is 360px. When I do this within firebug, the height of my picture changes as expected.

I then go into FileZilla and access the line of code (within Aptana) that reads “height: 360px;” and change it to “height: 800px;” I save the file and then overwrite the style.css file within my Remote Site. However, when I go back to my site and access the same element with Firebug, it still shows the height as 360px and the picture remains the same.

I tried changing all three “height” values (200, 280 & 360) to 800, but still, nothing changes.

I’m not sure what I’m doing wrong. Can anyone help me?

Please let me know if you need any additional information. I hope my question in coherent!

Thanks