Remove white space below image

If you would like to preserve the image as inline you can put vertical-align: top or vertical-align: bottom on it. By default it is aligned on the baseline hence the few pixels beneath it.

You're seeing the space for descenders (the bits that hang off the bottom of 'y' and 'p') because img is an inline element by default. This removes the gap:

.youtube-thumb img { display: block; }

You can use code below if you don't want to modify block mode:

img{vertical-align:text-bottom}

Or you can use following as Stuart suggests:

img{vertical-align:bottom}