To display HTML markup correctly, browsers create a special copy of the markup and insert it in a "virtual window" called a viewport. This window is often wider than the screen of the current device. This is done to make sure that all the elements fit as intended. This effect can be seen if you access a non-adapted HTML page from a mobile device. In this case a horizontal scroll bar will appear.
This meta tag first appeared in Apple's Safari browser. Before mobile devices, the Safari browser defaulted to 980 pixels wide for all web pages, which meant that the first versions of the iPod and iPhone didn't display sites in their entirety, but only the first 320 pixels of width.
Now this problem can be solved by specifying the width of the site for devices. The most commonly used value is
device-width which sets the page width equal to the screen width of the device.
<head> <meta name="viewport" content="width=device-width"> </head>
This value tells the browser that the width of the page is equal to the width of the device from which the page is viewed.
You may find it complicated now, but as you learn CSS, you'll get to fully understand the meaning of
viewport. For now, it's important to know about this meta tag and its main uses
Note that parameters are specified inside the
content attribute, where properties are separated by a comma.
The main parameters of the viewport meta tag
width— the width of the site. Given in pixels. It's possible to use the
device-widthvalue to set the page width as equal to the device width.
height— the height of the site. Given in pixels. It's possible to use the
device-heightvalue to set the page height as equal to the device height.
initial-scale— the initial scaling factor. It can take a value from 0.1 to 10. A value of 1 scales the page by default.
user-scalable— specifies whether the user can scale the page, that is, zoom in or out. It accepts
Specify a viewport with the following characteristics:
- Width: 980px
- Scale: 1
- Prohibit zoom. That is, make it impossible to zoom in or zoom out content using gestures or "hotkeys".
To do this, create a meta tag and specify the width. This is done with the
<meta name="viewport" content="width=980">
initial-scale should be set to
1.0. It means that the page will be displayed without any distortion, with the font sizes and other elements that were set by developers.
<meta name="viewport" content="width=980, initial-scale=1.0">
The last thing to do is to create a "ban" on scaling. To do this, add
user-scalable with the value
<meta name="viewport" content="width=980, initial-scale=1.0, user-scalable=no">
Basic use of the viewport meta tag
<meta name="viewport" content="width=device-width, initial-scale=1.0">
Add a viewport meta tag with a screen width of 1024 and no user scalability
The exercise doesn't pass checking. What to do? 😶
If you've reached a deadlock it's time to ask your question in the «Discussions». How ask a question correctly:
- Be sure to attach the test output, without it it's almost impossible to figure out what went wrong, even if you show your code. It's complicated for developers to execute code in their heads, but having a mistake before their eyes most probably will be helpful.
In my environment the code works, but not here 🤨
Tests are designed so that they test the solution in different ways and against different data. Often the solution works with one kind of input data but doesn't work with others. Check the «Tests» tab to figure this out, you can find hints at the error output.
My code is different from the teacher's one 🤔
It's fine. 🙆 One task in programming can be solved in many different ways. If your code passed all tests, it complies with the task conditions.
In some rare cases, the solution may be adjusted to the tests, but this can be seen immediately.
I've read the lessons but nothing is clear 🙄
It's hard to make educational materials that will suit everyone. We do our best but there is always something to improve. If you see a material that is not clear to you, describe the problem in “Discussions”. It will be great if you'll write unclear points in the question form. Usually, we need a few days for corrections.
By the way, you can participate in courses improvement. There is a link below to the lessons course code which you can edit right in your browser.