You have to match selectors in stylesheet based on read-only page structure.
You have to make the site preview in the bottom right look the same (and animate the same) as the page above. To do this, you should use CSS editor (bottom left) or even write page structure in HTML editor (top left).
Click on labels or adjust the slider to select game mode.
Use ctrl - z or button to undo.
To reverse your last undo click ctrl - alt - z.
If you have disabled auto-refresh in menu, use ctrl-s or to update preview.
In certain modes, if you are pro, you can disable hints.
Values showed on results page comes from computedStyle, but You should use relative (%, em, vw...) units.
To cancel dragging just drop block outside editor.
Remember to not declare the same selector twice.
In some levels, text is displayed as rectangles. This is because I'm bored by Lorem ipsum...
You can choose how do you want to play:
As the name suggests, your task is to complete CSS selectors. You can read page structure, but you can't modify it.
You have to drag blocks of CSS selectors, properties and values in to right place. Just like a puzzles.
Finally, you can write your own CSS without hints, but you can use the given ones. Writing HTML is beyond your duties. You should take a look at it.
Like in real life. Write page structure and stylesheet from scratch. We will give you some values to put in right places (ex. color, paddings...).
All is up to you. Level checking will propably broke. Use your creativity and share the solution with your friends.
I'm making this alone.