"Mozilla splash page" assessment

(Janet Swisher) #151

2 posts were merged into an existing topic: I have some questions as a Learning web development form beginner stage

(Janet Swisher) #152

8 posts were merged into an existing topic: “Silly story generator” assessment

(Janet Swisher) #156

A post was merged into an existing topic: “Silly story generator” assessment

(Janet Swisher) #158

2 posts were merged into an existing topic: “Typesetting a community school home page” assessment

(Janet Swisher) #165

2 posts were merged into an existing topic: “Silly story generator” assessment

(Janet Swisher) #167

2 posts were merged into an existing topic: “Adding features to our bouncing balls demo” assessment

(Janet Swisher) #169

2 posts were merged into an existing topic: “Silly story generator” assessment

(Janet Swisher) #171

6 posts were merged into an existing topic: “Structuring planet data” assessment

(Janet Swisher) #172

2 posts were merged into an existing topic: “Fundamental CSS comprehension” assessment

Learning web development: Marking guides and questions

Dear Mozilla,

First off, thank you for providing the excellent “Learn Web Development” tutorial and associated MDN resources. Phenomenal stuff.

I was wondering if you could provide some general feedback on my Mozilla-splash-page exercise. I noticed it doesn’t scale very well past < ~360px when inspected in responsive design mode (words / icons get truncated, go off screen) despite example solution picture being 321.5px and looking fine. Is that a default behavior or do I need to make some significant changes?


Any input appreciated.

Kind Regards
Martin P.

(Chris Mills) #174

Hi Martin,

Thanks for getting in touch. I’m so happy that you are enjoying the learning material :wink:

For the Splash Page example, your version looks really good, pretty much identical in output to our example! Well done.

the reason it starts to scroll horizontally and not look so great lower than 360px wide is that I have the CSS property min-width: 360px set on the body element. You’ve not done anything wrong.

If you remove that line from the styles.css file, it goes smaller without too much trouble, although the icon starts overlapping the heading.

Maybe I should remove that line from the exercise?


Hi Chris,

Thanks for the feedback. My thinking would be to leave the line in but make a note of that in the text. As in “Your result might be a little different, but don’t be alarmed, it’s b/c I’ve added the “min-width: 360px” line in my CSS for optimal viewing” kind of thing.


Damn. I sent the previous email too quickly by mistake (holding down ctrl+enter instead of shift + enter).

I was wondering if you could take a quick look at something else I’ve been having trouble with.


I’m currently working through the forms->buttons section and can’t get the examples to render properly in Mozilla. I thought it was just my running a simple local http.server module off of a python3 that’s the problem, but the problem persists on gh-pages as well.

The problems are the following (the associated code is at the very bottom of the page):

the “checked” Boolean attribute didn’t render for the checkboxes on local, it does on gh-pages (great)


    doesn’t render at all on either checkboxes or radio buttons (no bullet points - see slide attached), like it does in your examples on MDN

the checked radio buttons render checked like they should, but you can check multiple buttons (see slide attached) which from what I gather should not be possible (also after checking radio button you can’t uncheck it; ie it doesn’t uncheck itself when another button is checked)

Any input appreciated.

Kind Regards,



Never mind (see slide) :).

I have no idea why my brain failed to register and assimilate this information the first 3 times I’ve read it. Next time I’ll give it 48 hours and comprehensive re-reading of the article before I post anything as trivial here again.

List bullet-points still missing, though.

(Chris Mills) #178

I’ve decided to just remove it from the exercise. I don’t think it should be explained at this stage, because I’ve not taught any CSS at this point in the course.

(Chris Mills) #179

I am glad you got it sorted! The list bullets are missing because they have list-style: none set on them in the CSS.

(Marios Daskalas) #180

Can someone explain to me the usage of this code?

(Marios Daskalas) #181

I am kind of confused. We are going to examine this piece of code:

<img> srcset=“mozilla-dinosaur-head_120.png 120w,
mozilla-dinosaur-head_400.png 400w”
sizes="(max-width: 480px) 120px,
src=“mozilla-dinosaur-head_400.png” alt=“A funny description”>

If the width of the viewport is 350px then the image width is going to be exact 120px, otherwise it should be 400px. But in my case something else is happening. When I resize the browser window, I am inspecting the image dimensions with the developer tools and the image shrinks as the browse window shrunks, ignoring the rules that define the exact dimensions of the image when a certain criteria is met. I have used Google Chrome and Mozilla Firefox. The code editor that I used is Brackets and I am using Live Preview.

(Chris Mills) #182

This is a bit of a confusing situation, so let me try to explain.

The srcset attribute contains information on what images are available for use in this &lt;img&gt; element - it defines their filenames, and what their real width is (with the “w” unit).

The sizes attribute contains hints on what size slot the image will be expected to fill at a certain media condition. So here we are saying “when the viewport width is 480px or less, the expected slot size is 120px wide, otherwise the slot is more like 400px wide.” there is no exact sizing specified here - these are hints designed to allow the browser to make a sensible choice of what image file to load, based on the videwport size (or other media conditions, if specified).

So the effect this has is that if the viewport of your browser is 480px or less, the 120px wide image is loaded, but if not, the 400px image is used.

You can test it out; load this example: https://mdn.github.io/learning-area/html/multimedia-and-embedding/mdn-splash-page-finished/

Now open the browser dev tools, go to the Network tab, reload if necessary, then look at which dinosaur head image is downloaded. It should be the 400px one.

Now reduce your viewport width to really narrow, then do the same. You should now see that the 120px image is being loaded.

(Chris Mills) #183

The image still reduces in size when the viewport width is reduced, as shown on the screen , because it has max-width: 100% set on it in the CSS. This means that the image will always adjust its size to stay inside its parent element, as its width changes.