Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member

Defining a percentage-based page with ems

From: Typography with CSS in Dreamweaver

Video: Defining a percentage-based page with ems

As noted in the introductory video for this chapter, the percentage-based ems have a lot to recommend them, including easy scalability and better accessibility. However, defining your em sizes to match your pixel-based comps can be a hassle. Let me explain why and show you a way around that issue. If no percentage font size is declared, the default is assumed to be 100%. While this is fine, it makes it difficult to relate ems to pixel sizes. Let me walk you through the math.

Defining a percentage-based page with ems

As noted in the introductory video for this chapter, the percentage-based ems have a lot to recommend them, including easy scalability and better accessibility. However, defining your em sizes to match your pixel-based comps can be a hassle. Let me explain why and show you a way around that issue. If no percentage font size is declared, the default is assumed to be 100%. While this is fine, it makes it difficult to relate ems to pixel sizes. Let me walk you through the math.

The default font size for text in browsers is equivalent to 16 pixels. If a comp calls for text that's 14 pixels tall as with the paragraph text that we see here, you'll have to figure out the percentage of 16 that is equal to 14. While the math isn't really that difficult, it's 14 divided by 16, it's a pain to have to figure out for every heading, paragraph, table cell, and list item in a design. A far easier approach is to set the initial overall font size to 62.5%.

This has the effect of establishing a Base 10 System because 62.5% of 16 is 10. This means that if you wanted your p tags to be 14 pixels tall, you would make them 1.4 ems and your 26-pixel tall h1 would be 2.6 ems, and so on. Suddenly, your em conversion problem has vanished. So let's put that technique to practice and I'll show you how to overcome one of the ems measurement units inherent problems along the way.

So in Dreamweaver, I have opened resources.htm from the Chapter 2 > 02_03 folder, and I'm in Live view. My CSS STYLES panel now is open in Current mode, so we can make some selections and see the related rules. We're going to start by going to the body tag and changing the font size percentage. So here, you can see over in the CSS STYLES panel because no other element is selected on the page, it defaults to the body rule, and you can see by looking at the font property that we're using the shorthand technique.

So I'm just going to go ahead and put in the percentage size here, 62.5%. Now if you're not using the shorthand technique, you could just enter in a font-size property and make that 62.5%. I'll go ahead and hit Return and you'll see a radical change. So let's go in and make the necessary adjustments. I'm going to work top to bottom here. So let's go ahead and start off with the word, Resources, which as you can see is in a div called pageID, and over here we have the rule, #mainContent h1pageID.

So I'm going to go ahead and add in a font size for here, and according to the comp I'm following, which I don't have on screen, this should be 22.5 pixels tall. So I'll make that 2.25 ems. Now let's work with my h1 tag, the "Got questions" that you see here, and this will change the font size to the equivalent of 32 pixels or 3.2 ems.

Now I'm going ahead and just typing in the two letters em to make it a little bit quicker. If you're not that familiar with the syntax, you can always choose that option from the dropdown list. Alright, what about our main body paragraphs? So in this case, because I want this to be a more universal solution, I'm not going to go with the first rule that was selected, which is #mainContent #mainArticle p, instead I want to go for something more general which is #mainContent p or paragraph, and this will affect a paragraph anywhere, not just in the div called mainArticle.

So font size, we want this to be the equivalent of 16 pixels. So it's 1.6 ems and let's work our way down a little bit more. Here's a h2 tag that needs to be 25.5 pixels high. So now we'll add a font size equivalent to 25.5 pixels and I'm sure you've gotten into the rhythm of this, so we'll put in font size and make it 2.55 ems.

You're basically just shifting over the decimal point. Now let's do one without a decimal point, this h3 tag that we see here, we'll give it a font size equivalent to 20 pixels and now we've gotten all of our text headings and paragraphs handled. Let's continue to scroll down the page a bit. Everything is looking good, until we get to the list items. Now because these are in an li tag instead of a p tag, they still appear too small.

So we'll have to specify a CSS rule for them and the one we're looking for is the #mainArticle li and you can see that here. So we want this to appear the same size as the text, which if you recall, was 1.6 ems. So I'll put in a font size of 1.6 ems. Alright, looking pretty good! Now here is that catch that I've been telling you about with ems. Whenever you have a nested tag like a li inside of an li, you get a very strange reaction.

It actually can grow bigger. So what you need to do is to specify a rule just for this area. There's a couple of ways to approach this, but one primary technique is just to set the font size to 100% and that will work regardless of how many nesting levels that you have. Alright, I am going to go ahead and put my cursor in here and let me expand this box just a little bit, so you can see that, in fact, there already is a CSS rule for the nested list items. Here we have "#mainContent #mainArticle li li." So font size and we want this to be, as I said, 100% and again, I'm just going to go ahead and type that in.

Now everything is exactly the same size on our page and we're looking pretty good. Let's scroll down just a bit more. Now you'll notice that the footer paragraph, if I scroll back up, and the sidebar text are a bit small. I'll leave adjusting those CSS rules to you as practice for working with ems.

Show transcript

This video is part of

Image for Typography with CSS in Dreamweaver
Typography with CSS in Dreamweaver

36 video lessons · 8050 viewers

Joseph Lowery
Author

 
Expand all | Collapse all
  1. 3m 52s
    1. Welcome
      1m 19s
    2. Using the exercise files
      2m 33s
  2. 19m 16s
    1. Working with the Property inspector's HTML tab
      2m 0s
    2. Making the most of the Property inspector's CSS tab
      4m 57s
    3. Defining and changing type with the CSS Rule Definition dialog
      6m 16s
    4. Modifying type directly in the CSS Styles panel
      6m 3s
  3. 19m 45s
    1. Understanding type measurement unit options
      2m 50s
    2. Working with pixels
      2m 34s
    3. Defining a percentage-based page with ems
      6m 51s
    4. Letting users set page type size
      7m 30s
  4. 17m 36s
    1. Getting to know the basic font categories
      1m 32s
    2. Employing web-safe fonts
      3m 20s
    3. Defining new font families
      3m 22s
    4. Exploring CSS3 typeface options
      3m 9s
    5. Setting up @font-face
      6m 13s
  5. 9m 39s
    1. Dispelling the myth of web-safe colors
      1m 13s
    2. Applying color to type
      4m 52s
    3. Incorporating semi-transparent type
      3m 34s
  6. 19m 46s
    1. Setting the font-weight
      3m 48s
    2. Mandating font case
      2m 25s
    3. Exploring font variants
      1m 50s
    4. Utilizing white space effectively
      3m 40s
    5. Changing letter and word spacing
      2m 20s
    6. Defining first-line variations
      2m 19s
    7. Inserting drop caps
      3m 24s
  7. 20m 17s
    1. Applying CSS3 text effects
      5m 26s
    2. Designing type gradients
      8m 27s
    3. Rotating text with CSS transform
      6m 24s
  8. 15m 21s
    1. Implementing advanced headings with HTML5
      3m 11s
    2. Preparing CSS3 multiple-column layout
      4m 50s
    3. Future type: Defining CSS Regions
      7m 20s
  9. 24m 51s
    1. Styling unordered lists
      6m 51s
    2. Specifying a sequence with ordered lists
      5m 14s
    3. Applying definition lists
      7m 19s
    4. Targeting list items with CSS3 nth child
      5m 27s
  10. 20s
    1. Next steps
      20s

Start learning today

Get unlimited access to all courses for just $25/month.

Become a member
Sometimes @lynda teaches me how to use a program and sometimes Lynda.com changes my life forever. @JosefShutter
@lynda lynda.com is an absolute life saver when it comes to learning todays software. Definitely recommend it! #higherlearning @Michael_Caraway
@lynda The best thing online! Your database of courses is great! To the mark and very helpful. Thanks! @ru22more
Got to create something yesterday I never thought I could do. #thanks @lynda @Ngventurella
I really do love @lynda as a learning platform. Never stop learning and developing, it’s probably our greatest gift as a species! @soundslikedavid
@lynda just subscribed to lynda.com all I can say its brilliant join now trust me @ButchSamurai
@lynda is an awesome resource. The membership is priceless if you take advantage of it. @diabetic_techie
One of the best decision I made this year. Buy a 1yr subscription to @lynda @cybercaptive
guys lynda.com (@lynda) is the best. So far I’ve learned Java, principles of OO programming, and now learning about MS project @lucasmitchell
Signed back up to @lynda dot com. I’ve missed it!! Proper geeking out right now! #timetolearn #geek @JayGodbold
Share a link to this course

What are exercise files?

Exercise files are the same files the author uses in the course. Save time by downloading the author's files instead of setting up your own files, and learn by following along with the instructor.

Can I take this course without the exercise files?

Yes! If you decide you would like the exercise files later, you can upgrade to a premium account any time.

Become a member Download sample files See plans and pricing

Please wait... please wait ...
Upgrade to get access to exercise files.

Exercise files video

How to use exercise files.

Learn by watching, listening, and doing, Exercise files are the same files the author uses in the course, so you can download them and follow along Premium memberships include access to all exercise files in the library.


Exercise files

Exercise files video

How to use exercise files.

For additional information on downloading and using exercise files, watch our instructional video or read the instructions in the FAQ.

This course includes free exercise files, so you can practice while you watch the course. To access all the exercise files in our library, become a Premium Member.

Join now "Already a member? Log in

Are you sure you want to mark all the videos in this course as unwatched?

This will not affect your course history, your reports, or your certificates of completion for this course.


Mark all as unwatched Cancel

Congratulations

You have completed Typography with CSS in Dreamweaver.

Return to your organization's learning portal to continue training, or close this page.


OK
Become a member to add this course to a playlist

Join today and get unlimited access to the entire library of video courses—and create as many playlists as you like.

Get started

Already a member?

Become a member to like this course.

Join today and get unlimited access to the entire library of video courses.

Get started

Already a member?

Exercise files

Learn by watching, listening, and doing! Exercise files are the same files the author uses in the course, so you can download them and follow along. Exercise files are available with all Premium memberships. Learn more

Get started

Already a Premium member?

Exercise files video

How to use exercise files.

Ask a question

Thanks for contacting us.
You’ll hear from our Customer Service team within 24 hours.

Please enter the text shown below:

The classic layout automatically defaults to the latest Flash Player.

To choose a different player, hold the cursor over your name at the top right of any lynda.com page and choose Site preferencesfrom the dropdown menu.

Continue to classic layout Stay on new layout
Exercise files

Access exercise files from a button right under the course name.

Mark videos as unwatched

Remove icons showing you already watched videos if you want to start over.

Control your viewing experience

Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.

Interactive transcripts

Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.

Are you sure you want to delete this note?

No

Your file was successfully uploaded.

Thanks for signing up.

We’ll send you a confirmation email shortly.


Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from lynda.com.

Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

   
submit Lightbox submit clicked
Terms and conditions of use

We've updated our terms and conditions (now called terms of service).Go
Review and accept our updated terms of service.