Changing Font Size

Varying the size of text on a Web page is a great way to create visual interest and direct your visitors' attention to important areas of a page. Headlines in large type sizes capture your attention, while copyright notices displayed in small type subtly recede from prominence.

The font-size property sets text size. It's always followed by a unit of measurement, like so:

	font-size: 1em;

The value and unit you specify for the font size (in this example, 1em) determine the size of the text. CSS offers a dizzying selection of sizing units: keywords, ems, exs, pixels, percentages, picas, points, even inches, centimeters and millimeters.

Units of measurement commonly used with printed materials—picas, points, inches, and so on—don't work well on Web pages because you can't predict how they'll look from one monitor to the next. But you may have occasion to use points when creating style sheets for printer-friendly pages, as described in Chapter 13 (Section 13.1). Only a few of the measurement units—pixels, keywords, ems, and percentages—make sense when you're sizing text for a computer monitor. The rest of this section explains how they work.

Using Pixels

Varying Pixel values are the easiest to understand, since they're completely independent from any browser settings. When you specify, for example, a 36-pixel font size for an <h1> tag, the Web browser displays text that's 36 pixels tall, period. Web designers cherish pixel values because they provide consistent ...

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