Title style: font size + bold

Add custom CSS.

.wp-show-posts .wp-show-posts-entry-title {
	font-size: 28px;
	font-weight: bold;
}

You can also change the title tag to H1, H2, H3 etc if you prefer.

Thank you.
Where I have to put this custom CSS ?

Please help me:
Where I have to put this custom CSS ?

Somebody know where I have to put this custom CSS ?