how to remove the bold from a headline?

The heading looks bold because of its large size, if you have applied bold or want to change behaviour, you can do:

h1 { font-weight:normal; }

More: http://www.w3.org/TR/css3-fonts/#font-weight-prop

Try font-weight:normal;

h1 {
    font-weight: normal;
}

<h1><span style="font-weight:bold;">THIS IS</span> A HEADLINE</h1>

But be sure that h1 is marked with

font-weight:normal;

You can also set the style with a id or class attribute.

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