How to center content for all website pages?

Hi, as you can in my website, the content seems to be positioned a little to the left:

Do you know how I can center the content for all of my webpages?

In your master.css you would need to look for .entry and remove the left margin value and set it to 0. Apply the same to Content.

.entry {
    margin: 0 0 10px 0;
    font-size: 1.3em;

#content {
    float: left;
    width: 620px;
    margin-left: 0;