The font-size property allows you to
change the size of the font. You are able to specify the size of the
font in one of two ways. You can either use one of the pre-defined
CSS font-size keywords (xx-small, x-small, small, medium, large,
x-large, or xx-large) or you can manually type in your own font-size
amount.
To manually type in your own font-size amount you must
choose Other from the drop-down list of font sizes.
When you choose Other, it enables a textbox where
you can type in an amount and a drop-down list where you can choose a
CSS length unit. So, for example if you wanted to make your text 12pt
in size you would simply type "12" into the textbox and choose "pt"
from the drop-down list of CSS length units.
I should also point out
that when you enter a number into the font-size textbox, you can also
press the Up and Down arrow keys to increase or decrease it's amount
by 1. This allows you to easily preview different font sizes simply
by pressing Up or Down. If you type in a decimal amount (such as 1.5)
into the textbox and press the Up and Down arrow keys it will increase
or decrease its amount by 0.1. So for example, if the number 1.5 was
in the textbox and we pressed the Up arrow key, it would increase its
value to 1.6, or if we pressed the down arrow key it would decrease
it's value to 1.4, and so on.
When you specify a font-size manually, you can choose from
all of the available CSS length units including: px, %, em, in, cm, mm,
pt, pc, and ex. For an explanation of what the different CSS length
units mean, please consult the section of the help manual entitled
CSS Length Units.
Read an
official description of the font-size property from the W3C