[html] How do I set a background-color for the width of text, not the width of the entire element, using CSS?

What I want is for the green background to be just behind the text, not to be 100% of the page width. Here is my current code:

h1 { _x000D_
    text-align: center; _x000D_
    background-color: green; _x000D_
}

<h1>The Last Will and Testament of Eric Jones</h1> 

Try this one:

h1 {
    text-align: center;
    background-color: green;
    visibility: hidden;
}

h1:after {
    content:'The Last Will and Testament of Eric Jones';
    visibility: visible;
    display: block;
    position: absolute;
    background-color: inherit;
    padding: 5px;
    top: 10px;
    left: calc(30% - 5px);
}

Please note that calc is not compatible to all browsers :) Just want to be consistent with the alignment in the original post.

https://jsfiddle.net/richardferaro/ssyc04o4/

Easily :

<p>lorem ibsum....</p>

with styles :

p{
    background-color: #eee;
    display: inline;
}

the background sets to the whole size of the element; revise the diffrence between inline elements and block elements from here

can use html5 mark tag within paragraph and heading tag.

<p>lorem ipsum <mark>Highlighted Text</mark> dolor sit.</p>

You have to mention the width of the h1 tag..

your css will be like this

h1 {
text-align: center;
background-color: green;
width: 600px;
 }

As the other answers note, you can add a background-color to a <span> around your text to get this to work.

In the case where you have line-height though, you will see gaps. To fix this you can add a box-shadow with a little bit of grow to your span. You will also want box-decoration-break: clone; for FireFox to render it properly.

EDIT: If you're getting issues in IE11 with the box-shadow, try adding an outline: 1px solid [color]; as well for IE only.

Here's what it looks like in action:

.container {_x000D_
  margin: 0 auto;_x000D_
  width: 400px;_x000D_
  padding: 10px;_x000D_
  border: 1px solid black;_x000D_
}_x000D_
_x000D_
h2 {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
  font-family: Verdana, sans-serif;_x000D_
  text-transform: uppercase;_x000D_
  line-height: 1.5;_x000D_
  text-align: center;_x000D_
  font-size: 40px;_x000D_
}_x000D_
_x000D_
h2 > span {_x000D_
  background-color: #D32;_x000D_
  color: #FFF;_x000D_
  box-shadow: -10px 0px 0 7px #D32,_x000D_
    10px 0px 0 7px #D32,_x000D_
    0 0 0 7px #D32;_x000D_
  box-decoration-break: clone;_x000D_
}

<div class="container">_x000D_
    <h2><span>A HEADLINE WITH BACKGROUND-COLOR PLUS BOX-SHADOW :3</span></h2>_x000D_
</div>

A little late to game but thought I would add my 2 cents...

To avoid adding the extra mark-up of an inner span you could change the <h1> display property from block to inline (catch is you would have ensure the elements after the <h1> are block elements.

HTML

<h1>  
The Last Will and Testament of
Eric Jones</h1> 
<p>Some other text</p>

CSS

h1{
    display:inline;
    background-color:green;
    color:#fff;
}

Result

JSFIDDLE http://jsfiddle.net/J7VBV/

A very simple trick to do so, is to add a <span> tag and add background color to that. It will look just the way you want it.

<h1>  
    <span>The Last Will and Testament of Eric Jones</span>
</h1> 

And CSS

h1 { text-align: center; }
h1 span { background-color: green; }

WHY?

<span> tag in an inline element tag, so it will only span over the content faking the effect.

EDIT: the answer below would apply in most cases. OP however later mentioned that they could not edit anything other than the CSS file. But will leave this here so it may be of use to others.

The main consideration that others are neglecting is that OP has stated that they cannot modify the HTML.

You can target what you need in the DOM then add classes dynamically with javascript. Then style as you need.

In an example that I made, I targeted all <p> elements with jQuery and wrapped it with a div with a class of "colored"

$( "p" ).wrap( "<div class='colored'></div>" );

Then in my CSS i targeted the <p> and gave it the background color and changed to display: inline

.colored p {
    display: inline;
    background: green;
}

By setting the display to inline you lose some of the styling that it would normally inherit. So make sure that you target the most specific element and style the container to fit the rest of your design. This is just meant as a working starting point. Use carefully. Working demo on CodePen

HTML

<h1>
  <span>
    inline text<br>
      background padding<br>
      with box-shadow
  </span>
</h1> 

Css

h1{
  font-size: 50px;
  padding: 13px; //Padding on the sides so as not to stick.


  span {  
    background: #111; // background color
    color: #fff;
    line-height: 1.3; //The height of indents between lines.
    box-shadow: 13px 0 0 #111, -13px 0 0 #111; // Indents for each line on the sides.
  }
}

Demo on codepen

Option 1

display: table;

• no parent required

h1 {_x000D_
    display: table; /* keep the background color wrapped tight */_x000D_
    margin: 0px auto 0px auto; /* keep the table centered */_x000D_
    padding:5px;font-size:20px;background-color:green;color:#ffffff;_x000D_
}

<h1>The Last Will and Testament of Eric Jones</h1>

fiddle

http://jsfiddle.net/J7VBV/293/

more

display: table tells the element to behave as a normal HTML table would.

More about it at w3schools, CSS Tricks and here

Option 2

display: inline-flex;

• requires text-align: center; on parent

.container {_x000D_
    text-align: center; /* center the child */_x000D_
}_x000D_
h1 {_x000D_
    display: inline-flex; /* keep the background color wrapped tight */_x000D_
    padding:5px;font-size:20px;background-color:green;color:#ffffff;_x000D_
}

<div class="container">_x000D_
  <h1>The Last Will and Testament of Eric Jones</h1>_x000D_
</div>

Option 3

display: flex;

• requires a flex parent container

.container {_x000D_
  display: flex;_x000D_
  justify-content: center; /* center the child */_x000D_
}_x000D_
h1 {_x000D_
    display: flex;_x000D_
    /* margin: 0 auto; or use auto left/right margin instead of justify-content center */_x000D_
    padding:5px;font-size:20px;background-color:green;color:#ffffff;_x000D_
}

    <div class="container">_x000D_
      <h1>The Last Will and Testament of Eric Jones</h1>_x000D_
    </div>

about

Probably the most popular guide to Flexbox and one I reference constantly is at CSS Tricks

Option 4

display: block;

• requires a flex parent container

.container {_x000D_
  display: flex;_x000D_
  justify-content: center; /* centers child */_x000D_
}_x000D_
h1 {_x000D_
    display: block;_x000D_
    padding:5px;font-size:20px;background-color:green;color:#ffffff;_x000D_
}

<div class="container">_x000D_
  <h1>The Last Will and Testament of Eric Jones</h1>_x000D_
</div>

Option 5

::before

• requires entering words in css file (not very practical)

h1 {_x000D_
    display: flex; /* set a flex box */_x000D_
    justify-content: center; /* so you can center the content like this */_x000D_
}_x000D_
_x000D_
h1::before {_x000D_
    content:'The Last Will and Testament of Eric Jones'; /* the content */_x000D_
    padding: 5px;font-size: 20px;background-color: green;color: #ffffff;_x000D_
}

<h1></h1>

fiddle

http://jsfiddle.net/J7VBV/457/

about

More about css pseudo elements ::before and ::after at CSS Tricks and pseudo elements in general at w3schools

Option 6

display: inline-block;

• centering with position: absolute and translateX

• requires a position: relative parent

.container {_x000D_
  position: relative; /* required for absolute positioned child */_x000D_
}_x000D_
h1 {_x000D_
  display: inline-block; /* keeps container wrapped tight to content */_x000D_
  position: absolute; /* to absolutely position element */_x000D_
  top: 0;_x000D_
  left: 50%; /* part1 of centering with translateX/Y */_x000D_
  transform: translateX(-50%); /* part2 of centering with translateX/Y */_x000D_
  white-space: nowrap; /* text lines will collapse without this */_x000D_
  padding:5px;font-size:20px;background-color:green;color:#ffffff;_x000D_
}

  <h1>The Last Will and Testament of Eric Jones</h1>

about

More on centering with transform: translate(); (and centering in general) in this CSS tricks article

Option 7

text-shadow: and box-shadow:

• not what the OP was looking for but maybe helpful to others finding their way here.

h1, h2, h3, h4, h5 {display: table;margin: 10px auto;padding: 5px;font-size: 20px;color: #ffffff;overflow:hidden;}_x000D_
h1 {_x000D_
    text-shadow: 0 0 5px green,0 0 5px green,_x000D_
                 0 0 5px green,0 0 5px green,_x000D_
                 0 0 5px green,0 0 5px green,_x000D_
                 0 0 5px green,0 0 5px green;_x000D_
}_x000D_
h2 {_x000D_
    text-shadow: -5px -5px 5px green,-5px 5px 5px green,_x000D_
                  5px -5px 5px green,5px 5px 5px green;_x000D_
}_x000D_
h3 {_x000D_
    color: hsla(0, 0%, 100%, 0.8);_x000D_
    text-shadow: 0 0 10px hsla(120, 100%, 25%, 0.5),_x000D_
                 0 0 10px hsla(120, 100%, 25%, 0.5),_x000D_
                 0 0 10px hsla(120, 100%, 25%, 0.5),_x000D_
                 0 0 5px hsla(120, 100%, 25%, 1),_x000D_
                 0 0 5px hsla(120, 100%, 25%, 1),_x000D_
                 0 0 5px hsla(120, 100%, 25%, 1);_x000D_
}_x000D_
h4 { /* overflow:hidden is the key to this one */_x000D_
    text-shadow: 0px 0px 35px green,0px 0px 35px green,_x000D_
                 0px 0px 35px green,0px 0px 35px green;_x000D_
}_x000D_
h5 { /* set the spread value to something larger than you'll need to use as I don't believe percentage values are accepted */_x000D_
  box-shadow: inset 0px 0px 0px 1000px green;_x000D_
}

<h1>The First Will and Testament of Eric Jones</h1>_x000D_
<h2>The 2nd Will and Testament of Eric Jones</h2>_x000D_
<h3>The 3rd Will and Testament of Eric Jones</h3>_x000D_
<h4>The Last Will and Testament of Eric Jones</h4>_x000D_
<h5>The Last Box and Shadow of Eric Jones</h5>

fiddle

https://jsfiddle.net/Hastig/t8L9Ly8o/

More Options

There are a few other ways to go about this by combining the different display options and centering methods above.

HTML

<h1 class="green-background"> Whatever text you want. </h1>

CSS

.green-background { 
    text-align: center;
    padding: 5px; /*Optional (Padding is just for a better style.)*/
    background-color: green; 
}

h1 is a block level element. You will need to use something like span instead as it is an inline level element (ie: it does not span the whole row).

In your case, I would suggest the following:

style.css

.highlight 
{
   background-color: green;
}

html

<span class="highlight">only the text will be highlighted</span>

Try removing the text-alignment center and center the <h1> or <div> the text resides in.

h1 {
    background-color:green;
    margin: 0 auto;
    width: 200px;
}

You can use the HTML5 <mark> tag.

HTML:

<h1><mark>The Last Will and Testament of Eric Jones</mark></h1>

CSS:

mark
{
    background-color: green;
}