The element that contains the text string must be set to display: inline.

• If my element was inline-block, I’d get the desired effect right up until text spills onto a new line. At that point, subsequent lines would inherit the full width of the parent because of how inline-block works.
• If my element was a block element, it would always assume the full width of the parent (unless explicitly declared, which is not an option), thus leading to the same behaviour above.

Hello, this is a long line of text that spills onto multiple lines. Make it wrap.

This is the problem, if you want to adjust the line height so the text is more tightly set, the background clips the top and bottom of some text characters. Look at the lowercase g above.

Hello, this is a long line of text that spills onto multiple lines. Make it wrap.

You can see the other problem is that we need to add a padding on the text... but when set as inline block the text will only add left/right padding at the start and end of the text string, not the start and end of each line as rendered. Also, with this method any top/bottom padding will just increase the cropping / hiding of other lines of text.

So, how can we solve this? Luckily, CSS has thrown us a piece of candy in the box-decoration-break property. Let’s take a look.

The box-decoration-break: Property

The box-decoration-break CSS property specifies how the background, padding, border, border-image, box-shadow, margin and clip of an element is applied when the box for the element is fragmented. Fragmentation occurs when an inline box wraps onto multiple lines…

Basically, this property is giving us a bit more granularity in how an inline element gets rendered.

By default, it’s set to box-decoration-break: slice, which means that it treats the inline box as if it weren’t fragmented at all. I like to think of it like this.

Imagine that we took that multi-line inline element, stretched it out onto one line, applied the styling, sliced it into pieces, then moved each piece back to a new line. The result would be that the properties mentioned above would act on the entire box of the element, rather than each of its parts.

However, there is a second option for us, and that is: box-decoration-break: clone

When we set the property to clone, we can imagine a similar scenario as above, except one important thing. This time, let’s imagine that all the styles get applied after the element gets fragmented and distributed on multiple lines. In other words, paddings, borders, etc would be applied to each fragment almost as if they were separate elements.

Hello, this is a long line of text that spills onto multiple lines. Make it wrap.

Limitations

The h1 has to be inline, that means you can't offset the lines in any way. You can't use text-indent. Also you couldn't use text-align: justify; if you wanted to do that sort of thing.

You also can't use psuedo elements such as :first-letter or :first-line because The pseudo element only works if the parent element is a block container box.

The problem is still with line-height causing cropping on the text :(

Also any top padding you add will result in a row cropping text in the row above.

So really this solution has limited appeal.

Hello, this is a long line of text that spills onto multiple lines. Make it wrap.

The advantages are that you can apply all these properties on one element, no need for a parent wrapper or new elements for each subsequent line of text. This solution is therefore also more responsive in that you can resize the container smaller and the line padding will still work as expected.

Gradient backgrounds

Hello, this is a long line of text that spills onto multiple lines. Make it wrap.

Fine when using a gradient from left to right

Hello, this is a long line of text that spills onto multiple lines. Make it wrap.

But not top to bottom

Box-shadow technique

We can use box-shadow to add left and right padding to each line of our inline element.

...However that shifts the padding over to the left and unless you use a parent element around it you can't shift it over again using padding or margin, because it'll just add it to the first line otherwise.

We control the top and bottom padding with a mix of line-height and padding-top/bottom. unfortunately this is a balancing act, you still can't have tightly set lines and large top/bottom padding.

This technique works much better with uppercase text, that way there arent hanging ligatures to be cropped off

This is working in Chrome and Safari, and now working in Firefox 32+, in my quick tests. Chrome and Safari require it to be -webkit-box-decoration-break.