I have an h1 I want to fit the entire width of the viewport which consists of 13 characters in a monospaced font. After reading the CSS-Tricks article on viewport sized typography it seems like logically if I want to achieve this I simply have to set my h1's styles to:
h1 {
font-size: 13vw;
font-family: monospace;
}
This however is rendering with a bit of space left over (highlight the text to see the white space):
(There would be an image here but I don't have enough rep so click here for the JSFiddle)
I have tried other sizes, font-size: 14vw; is slightly too big, font-size: 13.99vw; seems just right, but strangely font-size: 13.999vw; is still too big?
Can someone explain what is going on here? Why would each character of a 13 character length string in a monospaced font require more than (100/13)% of the viewport width to fit the entire viewport width?
Before I begin I'm just going to say that I'm not going to give you a workaround due to issues I've raised in comments on Stoyan Dekov's answer. Instead I'm only going to answer your question of Can someone explain what is going on here?
font-size != width
The problem here is that you're assuming font-size is the same thing as width. It isn't. The CSS Fonts Module defines font-size as:
...the desired height of glyphs from the font.
This means that font-size is more comparable to height than it is to width.
This isn't specific to the vw unit, either. If you specify a font-size in pixels you'll also notice that the computed width does not match the font-size.
But even then it all depends on which font-family you're using anyway, as the same paragraph continues to say:
For scalable fonts, the font-size is a scale factor applied to the EM unit of the font. (Note that certain glyphs may bleed outside their EM box.) For non-scalable fonts, the font-size is converted into absolute units and matched against the declared font-size of the font, using the same absolute coordinate space for both of the matched values.
The key words here being scalable and non-scalable.
Even if a non-scalable font was being used though, 13vw would not reflect each character's width. This would never work with vw, but it may work with vh but only if the aspect ratio of each individual character matched the screen's aspect ratio.
The problem is if a text is the exact same size as the parent container, it will span across a second line.
body {
margin: 0;
width:100px
}
h1 {
font-family: monospace;
width:100px;
}
That will cause the text to go onto a new line as they are both 100px. That's why 14vw is too big, but 13.99 is just enough: Fiddle DEMO
However, you can use text-align: justify; to achieve what you want.
Take a look at this Fiddle DEMO.
Related
I'm hoping to use VW units to size my typography, but when doing so the text is huge and obviously larger than the viewport width. Essentially I want my text to be responsive within the parent .container, so the text is never cropped or overflowed as it would be if using a static size unit like px or em?
HTML
<div class="container">
<h1>Responsive Typography!</h1>
</div>
CSS
.container {
width: 100%;
background: red;
height: 100%;
}
h1 {
font-size: 40vw;
}
FIDDLE
Your Fiddle is rendering correctly.
font-size, classically, referred to the width of a capital letter M. Let's go with that for now.*
1vw is 1% of the viewport width.
Thus, font-size: 40vw roughly means "render this text such that the width of a capital letter M would be 40% of the viewport width". In other words, each individual character is going to be pretty huge.
It's not going to break to a new line because it's all one word, and CSS only breaks between words by default. (To break on characters within a word, you would use word-break: break-all on the element. It usually looks terrible, though.)
You confirmed in a comment that you're trying to scale up the font size in your header so that the full text in it is some percentage of the viewport width. Depending on your circumstances, you can either
use a smaller font-size, still in vw, and accept that text won't always be a predictable fixed width; or
try something like FitText to dynamically resize the font.
It's a shame, but there isn't a way to do quite what you want with pure CSS; as is often the case your choices are to compromise on your design goal or use some clever JS/hacks to achieve it.
* A note on font-size: what I said above isn't really how font-size is worked out; it just happens to be close enough for most fonts and it makes my answer easier to read. The actual situation is more complicated.
A more accurate rule-of-thumb is the body height, i.e. the vertical distance from the top of an ascender (upper part of letters like b, d and h) to the bottom of a descender (lower part of letters like g, j and p) on the same line. However, even this is very course and often wrong; it ultimately comes down to the font metrics, and will vary significantly between fonts.
There are many articles and questions about percentage-sized vs other-sized fonts. However, I can not find out WHAT the reference of the percent-value is supposed to be. I understand this is 'the same size in all browsers'. I also read this, for instance:
Percent (%): The percent unit is much like the “em” unit, save for a few fundamental differences. First and foremost, the current font-size is equal to 100% (i.e. 12pt = 100%). While using the percent unit, your text remains fully scalable for mobile devices and for accessibility.
Source: http://kyleschaeffer.com/best-practices/css-font-size-em-vs-px-vs-pt-vs/
But if you say "ie 12 pt = 100%", then it means you first have to define font-size: 12pt. Is that how it works? You first define a size in an absolute measure, and then refer to this as '100%'? Does not make a lot of sense, as many samples say it is useful to put:
body {
font-size: 100%;
}
So by doing this, WHAT is the font size relative to? I notice that the size I see on my screen differs for every font. Arial looks way bigger than Times New Roman, for instance. Also, if I would just do this, body size = 100%, would that mean that it will be the same on all browsers? Or only if I first define an absolute value?
UPDATE, SAT JUL 23
I am getting there, but please bear with me.
So, the % value relates to the default browser font size, if I understand correctly. Well, that is nice but gives me again several other questions:
Is this standard size always the same for every browser version, or do they vary between versions?
I ! found (see image below) the settings for Google Chrome (never looked at this before!), and I see standard "serif", "sans-serif" and "monospace" settings. But how do I interpret this for other fonts? Say I define font: 100% Georgia;, what size will the browser take? Will it look up the standard size for serif, or has the "Georgia" font a standard size for the browser
On several websites I read things like Sizing text and line-height in ems, with a percentage specified on the body [..], was shown to provide **accurate, resizable text across all browsers** in common use today. But from what I am learning now I believe that you should actually choose between either resizable text (using % or em, like what they recommend in this quote), or having 'accurate, consistent font-sizes across browsers' (by using px or pt as a base). Is this correct?
Google Settings:
This is how I think things could look like if you do not define the size in absolute values.
The browser default which is something like 16pt for Firefox, You can check by going into Firefox options, clicking the Content tab, and checking the font size. You can do the same for other browsers as well.
I personally like to control the default font size of my websites, so in a CSS file that is included in every page I will set the BODY default, like so:
body {
font-family: Helvetica, Arial, sans-serif;
font-size: 14px
}
Now the font-size of all my HTML tags will inherit a font-size of 14px.
Say that I want a all divs to have a font size 10% bigger than body, I simply do:
div {
font-size: 110%
}
Now any browser that view my pages will autmoatically make all divs 10% bigger than that of the body, which should be something like 15.4px.
If I want the font-size of all div's to be 10% smaller, I do:
div {
font-size: 90%
}
This will make all divs have a font-size of 12.6px.
Also you should know that since font-size is inherited, that each nested div will decrease in font size by 10%, so:
<div>Outer DIV.
<div>Inner DIV</div>
</div>
The inner div will have a font-size of 11.34px (90% of 12.6px), which may not have been intended.
This can help in the explanation:
http://www.w3.org/TR/2011/REC-CSS2-20110607/syndata.html#value-def-percentage
My understanding is that when the font is set as follows
body {
font-size: 100%;
}
the browser will render the font as per the user settings for that browser.
The spec says that % is rendered
relative to parent element's font size
http://www.w3.org/TR/CSS1/#font-size
In this case, I take that to mean what the browser is set to.
A percentage in the value of the font-size property is relative to the parent element’s font size. CSS 2.1 says this obscurely and confusingly (referring to “inherited font size”), but CSS3 Text says it very clearly.
The parent of the body element is the root element, i.e. the html element. Unless set in a style sheet, the font size of the root element is implementation-dependent. It typically depends on user settings.
Setting font-size: 100% is pointless in many cases, as an element inherits its parent’s font size (leading to the same result), if no style sheet sets its own font size. However, it can be useful to override settings in other style sheets (including browser default style sheets).
For example, an input element typically has a setting in browser style sheet, making its default font size smaller than that of copy text. If you wish to make the font size the same, you can set
input { font-size: 100% }
For the body element, the logically redundant setting font-size: 100% is used fairly often, as it is believed to help against some browser bugs (in browsers that probably have lost their significance now).
Sorry if I'm late to the party, but in your edit you make a remark about font: 100% Georgia, which the other answers haven't responded to.
There is a difference between font: 100% Georgia and font-size:100%; font-family:'Georgia'. If that was all the shorthand method did, the font-size part would be meaningless. But it also sets a lot of properties to their default values: the line height becomes normal (or around 1.2), ditto for the style (non-italic) and weight (non-bold).
That's all. The other answers already mentioned everything else there was to mention.
It's relative to default browser font-size unless you override it with a value in pt or px.
As you showed convincingly, the font-size: 100%; will not render the same in all browsers. However, you will set your font face in your CSS file, so this will be the same (or a fallback) in all browsers.
I believe font-size: 100%; can be very useful when combining it with em-based design. As this article shows, this will create a very flexible website.
When is this useful? When your site needs to adapt to the visitors' wishes. Take for example an elderly man that puts his default font-size at 24 px. Or someone with a small screen with a large resolution that increases his default font-size because he otherwise has to squint. Most sites would break, but em-based sites are able to cope with these situations.
According to ALL THE SPECS DATING BACK TO 1996, percentage values on font-size refer to the parent element's (computed) font-size.
<style>
div {
font-size: 16px;
}
span {
font-size: 75%;
}
</style>
<div><span>this font size is 12px!</span></div>
It's that easy.
What if the div declares a relative font-size, like ems, or even worse, another percentage?? See “computed” above. Whatever absolute unit the relative unit converts to.
The only question that remains is what happens when you use a percentage value on the root element, which has no parent:
html {
font-size: 62.5%; /* 62.5% of what? */
}
In that case, see the “duplicate” of this question. TLDR: percentages on the root element refer to the browser default font size, which might be different per user.
References:
CSS 1 spec (1996)
CSS 2.1 spec (2011)
CSS Fonts Level 3 spec (2013)
CSS Fonts Level 3 editor’s draft (2017)
Relative to the default size defined to that font.
If someone opens your page on a web browser, there's a default font and font size it uses.
As to my understanding it help your content adjust with different values of font family and font sizes.Thus making your content scalable. As to the issue of inhering font size we can always override by giving a specific font size for the element.
I wasn't sure how to word the question for this topic...sorry.
I'm just starting to learn CSS.
I have a <div> with a background image and there is text within the <div>. I read that choosing font sizes in em is a good choice because some people might require larger text sizes in their browsers. So setting the font-size with em would accommodate these types of users better.
But the problem with allowing the text to be resized, is that in many cases, the text within my <div> is going to go beyond the size of the background image and make the page look terrible and poorly designed.
Is there a way to use CSS and allow the background image to 'match' or 'expand' to accommodate to larger text size?
You could set the width of the div to the img width so that it never expands wider (beyond the image).
Of course, the enlarged text would force the div to grow height-wise.
You could also set the background-img to repeat (if the image allows for it), so that when the text expands, the image is repeated.
background-image:url('whatever.png');
background-repeat:repeat-x;
// x = horizontal, y = vertical
Since you are starting out, you might want to read http://na.isobar.com/standards/#_pixels_vs_ems wherein they say:
We use the px unit of measurement to
define font size, because it offers
absolute control over text. We realize
that using the em unit for font sizing
used to be popular, to accommodate for
Internet Explorer 6 not resizing pixel
based text. However, all major
browsers (including IE7 and IE8) now
support text resizing of pixel units
and/or full-page zooming. Since IE6 is
largely considered deprecated, pixels
sizing is preferred. Additionally,
unit-less line-height is preferred
because it does not inherit a
percentage value of its parent
element, but instead is based on a
multiplier of the font-size.
Correct:
#selector {
font-size: 13px;
line-height: 1.5; /* 13 * 1.5 = 19.5 ~ Rounds to 20px. */
}
Incorrect:
/* Equivalent to 13px font-size and 20px line-height, but only if the browser default text size is 16px. */
#selector {
font-size: 0.813em;
line-height: 1.25em;
}
We have a CSS file with some rules similar to the following:
.directory-result ul
{
margin-top: 20px;
width: 60em;
}
.about-text
{
margin-top: 1em;
margin-bottom: 1em;
}
Everything is working ok, but we're wondering specifically about the inconsistencies between the margin-top values. One is 20px and the other is 1em.
Which is the best one to go with? What are the points I should consider when deciding which to use? Thanks.
em units are used for better scalability of the page when the size of the elements depend on the page's scale. It's especially important for old browsers (e.g. IE6) and mobile platforms.
px units are used for absolute values, while em is relative to the font size of the particular element.
1em means one font-line, e.g. you have a box with font-size 12px that means that 1em will be equal to 12px
Also, using px seems easier because you know the exact value, but em units inherit the value of their container.
<p>Text</p>
<div class="box">
<p>Lorem</p>
</div>
p {
font-size: 1.2em;
}
.box {
font-size: 1.2em;
}
In this case, the first <p> will have font-size equal to the basic font-size * 1.2, and the second <p> will display with font-size * 1.2 * 1.2.
They're simply two different ways of measuring. Em is linked to the font size (traditionally, 1em is roughly the width of the letter M in a given typeface), while px is pixels.
If you build everything using em, everything will scale accordingly when the user adjusts their font size (e.g. using IE's Page > Text Size menu). It also makes it easier to work to a vertical rhythm.
Pixels are better when you want to build something "pixel-perfect". Be aware that a CSS pixel doesn't always equal a screen pixel - mainly because modern browsers and mobile devices allow for zooming. This isn't usually a problem though because the entire page is scaled accordingly.
Whatever you do, make sure you're consistent throughout - it makes life much easier later on.
The ems unit is relative to the current font size in the browser. So if the user increases the font size*, or if you change an element’s font size in the CSS, the margins should still look “right” in proportion to the text.
*(This ceases to matter if the user zooms the page instead of increasing the text size (as is the default in Firefox and Chrome now, and is an option in IE).
If you're using a margin to position something a set number of pixels away from something else, then you should obviously stick with pixels.
Also here is a very good in depth tutorial:
px – em – % – pt – keyword
In this example directory-result ul represents a block - some sort of list/menu where pixel dimensions are quite important. We can’t always rely on em which defines the text size, because if we need 20px space due to some background image – well, we need 20px, no compromises.
Note that you can't create and save the image i.e. 10em wide, therefore I see no reason why should I use different units on a web page. It just creates confusion and later on it is very difficult to maintain the layout.
There is a one place though, where using em is advisable – I’m talking about text blocks. I’m guessing in your code about-text is placed within other text where adding top/bottom margin of 1em (height of text) makes sense. It’s like in any text editor (i.e. line spacing in MS Word) – text looks best when spacing between lines is defined by multiplying the height of text
So in my opinion – everywhere where you deal with design and you use images by default measured in pixels – usepixels for all padding/margin.
Everywhere where you deal with text inside a text block, and you want to add even spacing between the text nodes – useem.
I'd like to try and convert my designs from pixels to ems. I've read so many tutorials that... and I'll leave it right there.
Starting with this as my base:
body {
font-size: 62.5%;
line-height: 1.4;
}
... now this is where I get lost...
Should I be defining my font-size like this:
div#wrapper { font-size: 1.5em; }
... or like this:
blockquote, li, p, dt, dd, etc { font-size: 1.5em }
And then the next thing I don't really understand is where ELSE should I be using ems in addition to font-size and line-height? I will be using a fixed-width layout using 960.gs.
line-height: 1.4em;
Probably isn't what you want. The line-height will stay at the same computed height for the size of an ‘em’ on that element, even when you change the font-size on a descendant element.
line-height has a special case where it allows a unitless number:
line-height: 1.4;
Which makes each descendant line-height depend on its own font-size rather than the ancestor's.
Should I be defining my font-size [on a wrapper or on many element types]?
Well that rather depends on what you're trying to do. With relative font-sizes it is generally best to keep the number of declarations down to a minimum, because they nest: that is, with your blockquote { font-size: 1.5em; }, if you put a blockquote inside a blockquote you'd get a font-size of 1.5*1.5=2.25em compared to the body font size. Is that what you want? Maybe, maybe not.
where ELSE should I be using ems
Anywhere you want the size of an element to respond to the user's preferred font-size. One common example would be something like:
#maintext {
width: 60%;
min-width: 8em;
max-width: 40em;
}
to try to restrict text lines to a reasonable column width when doing liquid layout.
But if you are limiting yourself to a fixed-width layout it may not make sense to make element widths font-size-dependent.
You may find How to size text using ems an interesting and helpful read. The thing that I try to remember is my conversion from ems to pixels.
In your example:
body {
font-size: 62.5%;
line-height: 1.4em;
}
1 em is equal to 10 pixels if the browser default text-size is 16px. The line height would then be equal to 14 pixels. Like bobince beings out, I would use a unitless line-height value.
To help you with your calculations, you can use an Em Calculator. It allows you to easily convert between ems and pixels.
The problem with em is that it is a relative unit. Inheritance and relativity don't mix well in HTML documents. What I do is use px for font size and box dimensions / positioning, but try to use em for line-height, margin / padding, etc...
I'm sure it's not the "proper" way to do it, but the system was pretty poorly designed from the start, if you ask me.
ems are relative, so if you set:
body {
font-size: .6em;
}
Everything will be relative to that.
Which means (and this is where my head starts to hurt too) that if an h1 has a default font size of 250% larger than most other text (p, li), the header will now be 60% of that default size. So it will still be 2.5 times bigger than the other stuff, but it will be 60% smaller than if you hadn't set the rule at all.
Now, if you then say that :
h1 {
font-size: 1.2em;
}
The h1 will now be 20% larger than what it would be if you hadn't set the rule, so it's 20% larger than the already shrunken down 60% smaller from the first rule. This means that it will no longer be in direct proportion to the browser's default for h1 and other elements.
So basically, you should set your font-size up front for the whole document (like in the first rule I showed), and this is your baseline. After that, you set how you want any individual elements to be sized in relationship to each other (basically in relationship to what they already are)...
So if you know you want all of the fonts in the #wrapper div to be 1.5em from their default, setting it there is perfect. But if you want to change the size of blockquote so that it's a tad smaller, you'd still set the rule for #wrapper, but then make a second rule for blockquote.
If you want to set up page width by using em's, follow this pattern provided by YUI development team
Divide your desired pixel width by 13; the result is your width in ems for all non-IE browsers. For IE, divide your desired pixel with by 13.3333 to find the width in ems for IE.
Here's an example of a custom page width of 600px, and here's what the CSS looks like:
600 px / 13 = 46.15 (non-IE browsers)
600 px / 13.33 = 45.00 (IE browsers)
#custom-doc {
margin:auto;text-align:left; /* leave unchanged */
width:46.15em;/* non-IE */
*width:45.00em;/* IE */
min-width:600px;/* optional but recommended */
}
regards,