Non-Responsive Site: Jumping Spider Diaries

Download the site folder above and unzip it (view the page in the browser.)

Rename the site folder responsive, because that’s what you’re going to make it.

Elements of Responsive Design

Ems Versus Pixels

Instead of using px for font sizes, use the unit of measurement called em. An em is a unit equal to your default font size. In most browsers, the default font size is 16px, so 1em is equal to 16px. Everything is then measured in terms of em. This makes your website more scalable for all devices.


To calculate em instead of px, use the handy formula above.

Example: if you want the #wrapper’s font to be 14px, the formula is:

14/16 = 0.875em

That’s “target of 14px divided by default font size of 16px equals 0.875em”.


Once you define a main em size for fonts in a given container, font sizes within that container now have a new context.

Example: if I now want an H1 inside the #wrapper to be 36px, I need to use this formula:

36/14 = 2.571428571428571em

That’s “target of 36px divided by #wrapper font size of 16px equals 2.571428571428571em”.

Yes, you really will see em sizes with tons of decimal places in responsive designs.

RESPONSIVE EXERCISE 1: Font-size in ems

Change the <title> for the home page for the Jumping Spiders Diary site to “Responsive Layout.”

In the stylesheet, swap all the font sizes from px to ems. Round to five decimal places. Leave yourself some CSS comments after each change to remind you what the original pixel sizes were.

Example: font-size: 4.42857em; /* 62px */

Test in the browser to confirm that all your font sizes are the same as before.

Fluid Grids

Fluid grids respond to the open width of the browser window. The wider or narrower the window, the wider or narrower the content and columns within it


For a grid to be fluid, widths of all box elements must be defined as percentages instead px. This includes:

  • width
  • margins
  • paddings
  • borders

Within a given container, the total widths of all its children ought to add up to 100%. This makes all the page content areas resize proportionally as the browser resizes.

Currently, the Jumping Spider Diaries uses fixed widths.


Along with fluid grids, designers can use media queries to detect the current width of the browser window, known as theviewport, and adapt the layout accordingly.

Example: Try resizing the window with Smashing Magazine in it. Notice how the multiple sidebars find new places to live according to hierarchy? Here’s what the site looks like on a wide-screen monitor:

responsive layout Smashing Magazine on widescreen monitor

This rearranging of page content block is being accomplished partly through the use of media queries. More on these later.

Percentages Versus Pixels

The formula you use to calculate percentages is similar to the one for figuring out ems: Target / Context = Result, except now you need to multiply the result by 100.

Example: if my wrapper is 960px and I want to convert my 300px sidebar into a percentage:

300/960 * 100 = 31.2525%

That’s “target of 300px divided by #wrapper width of 960px equals 0.3125; multiply by 100 for 31.25%”.

RESPONSIVE EXERCISE 2: Widths in percentages

In the stylesheet for the Jumping Spiders Diary site, swap all the widths from px to percentages for the following boxes. Round to five decimal places.

  • nav (originally 180px)
  • article (originally 600px)
  • aside (originally 180px)

For the wrapper, set it to 100% width but limit its width to no greater than 960px, and no smaller than 350px, like this:

#wrapper {
width: 100%;
max-width: 960px;
min-width: 350px;

Again, leave yourself comments as to the original sizes in pixels when they are converted to percentages.

Now check the page in a browser while you resize the window. How can we make things work better?

Proportional Paddings and Margins

Paddings and margins should all be defined as percentages too, when they occur on the left and right within a container.

Example: if my sidebar was originally set to 300px and I have an H1 inside it with a margin of 15px, I need to calculate what percentage of 300 15 is.

15/300 * 100 = 5%

RESPONSIVE EXERCISE 3: Proportional padding and margins

In the stylesheet for the Jumping Spiders Diary site, replace margin-left, margin-right, padding-left and padding-right values with percentages. Round to five decimal places.

For example, I might change margin: 5px 20px; to margin: 5px 7.25%;

If a padding or margin is already set to 0, leave it alone; zero works for any unit of measurement.

You might need to rethink the way selectors are combined to address the various contexts. In particular, you’ll need to split out this one: h1, h2, h3, h4, h5, h6, p

Leave copious CSS comments again.

Test in a scaling browser window again. Now, what else needs to be fixed?

Scalable Images

Images can be set to a specific width in the markup, but then given a maximum width given their context, using max-width: 100%;

This assures that images will resize when their containers get smaller than they are.

Example: I want any images placed in the markup to get smaller when they no longer have room to fit inside their respective containers.

img {
max-width: 100%;
height: auto;

Height: auto overrides any height attributes set in your img tags.

RESPONSIVE EXERCISE 4: Scalable images

In the markup for the Jumping Spiders Diary site, remove all height attributes from the img tags.

In the stylesheet, set the max-width for all images to 100%;

Test in the browser. We’re getting somewhere, but it’d be nice to have the page sections stack on top of each other at some point when the browser gets too narrow, instead of squishing themselves three-across.

Implementing Adaptive Design

The adaptive design approach means using the same markup but adapting the CSS to various viewports, using media queries. You can do adaptive layouts without using a fluid grid. Ours is already fluid, but the following techniques can be used with a fixed-width site.

The first thing you need to do is determine the browser widths at which your layout will need to change.

Finding Your Breakpoints

Resize the Jumping Spider Diaries home page, starting from full size, down until you feel like some or all of the content is getting too tight horizontally. Determine how wide the browser window is at this point—that’s your first breakpoint.

One way to measure the width of your browser window is with Tools > Web Developer > Responsive Design Viewin Firefox. You may know of other methods, but this tool is especially designed to make your responsively-designing life easier.

Make a note of how wide the screen must be at a minimum to maintain its current page content arrangement. Then determine what needs to go where when the page gets narrower than that width.

RESPONSIVE EXERCISE 5: First breakpoint

Find your first breakpoint in the spider home page. Decide what needs to move out of the way, and where to, when the browser gets smaller than that breakpoint. What else should adapt/resize?

Creating Media Queries

A media query is something you wrap around a set CSS rules that tests for certain things going on in the browser, and applies those rules if the query is positive.

You should always put media queries at the bottom of your stylesheet, or even in another stylesheet, so that they override all previously-defined styles if the given criteria is met.

Take a look at this one:

@media screen and (max-width: 460px) {
header h1 {
font-size: 1.5em; /* 24px */

This media query checks whether the rendering device is a screen (as opposed to a printer or other non-display device,) and it checks whether the browser window has reduced to 460px wide or less. If both of these are the case, the h1 in the header is given a new font-size.

There are many other things you can check for in the browser environment, but we will focus today on screen and max-width.

Notice the additional set of { } brackets.

RESPONSIVE EXERCISE 6: First media query

Write a media query at the bottom of your stylesheet which tests for screen and your breakpoint width defined in exercise 5 above.

Write some rules inside your media query that change the layout and resize things to provide a better user experience at this size.

For example, you might remove float:left from a page block, with an according adaption of the widths for it and its neighboring block(s).

If you want to set the menu horizontally, you can add a float:left to it (but make sure there’s room to do it—it can’t be a sidebar anymore!)

Viewport Meta Tag

Some devices may ignore your responsiveness and instead try to show your website full-width and zoomed out. This is okay for non-responsive sites, but you don’t want that browser behavior to happen on your site.

So we add a bit of markup into the head of our HTML page:

<meta name=”viewport” content=”initial-scale=1.0, width=device-width”/>

This tells the browser that the width of the browser window should be treated the same as the overall device width.

RESPONSIVE EXERCISE 7: Viewport meta tag

Add the viewport meta tag to your index page.

Implementing Responsive Design

Responsive websites are built on a fluid grid and use media queries not to target specific device resolutions, but rather to adjust the design and content as it reaches various breakpoints.

So, you have everything you need to create a basic responsive site! There are a lot more techniques available out there, and more being suggested all the time, but this is all you really need to get started:

  • define font-sizes in ems
  • define page block widths in percentages
  • make margins and paddings on the left and right proportional with percentages
  • make images scale
  • identify breakpoints
  • write media queries for breakpoints

RESPONSIVE EXERCISE 8: Complete your responsive design

Define at least three more breakpoints for the Jumping Spider Diaries home page, and give each breakpoint a media query with some new CSS rules.

Here are screenshots of how I configured my site at reducing widths. Try to match these.

responsive site at 1024px width
responsive site at 974px width
responsive site at 910px width
responsive site at 640px width
responsive site at 460px width

Mobile First

The trend toward mobile is picking up a lot of speed. There will come a time very soon in which the majority of traffic on websites is coming from mobile devices. It is for this reason that many web designers are now thinking “mobile first.”

The mobile first philosophy involves designing your layout for the smallest mobile design initially, and then working in the opposite direction from our approach in today’s lesson. Smaller-to-bigger, not bigger-to-smaller.

In the mobile first method, you would write all of your CSS for the basic site according to what works at about 350px across. Then your breakpoints work from in to out. When working this way, your media queries at the bottom of your stylesheet start with the next narrowest breakpoint (say 450px,) and go larger as you go down the page.

Instead of using max-width, then, you would use min-width.


@media screen and (min-width:768px) {
.main {
.complementary {

More Responsive Concepts

Ready for much more about responsive design? Here’s the first in a series of articles that go into greater depth about each topic I outlined:

Build a responsive site in a week: designing responsively

Video Tutorials

Here’s a great set of video/interactive tutorials on implementing responsive web design:

Build a Responsive Web Site

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