Line-height. Summary On block level elements, the line-height CSS property specifies the minimal height of line boxes within the element. On non-replaced inline elements, line-height specifies the height that is used in the calculation of the line box height. On replaced inline elements, like buttons or other input element, line-height has no effect. [1] Initial value normal Applies to all elements Inherited yes Percentages refer to the font size of the element itself Media visual Computed value for percentage and length values, the absolute length, otherwise as specified Animatable yes, as a number, a length Canonical order the unique non-ambiguous order defined by the formal grammar Syntax Formal syntax: normal | <number> | <length> | <percentage> line-height: normal line-height: 3.5 /* <number> values */ line-height: 3em /* <length> values */ line-height: 34% /* <percentage> values */ line-height: inherit Values normal Depends on the user agent.
Relative to the font size of the element itself. Examples. <length> The <length> CSS data type denotes distance measurements. It is a <number> immediately followed by a length unit (px, em, pc, in, mm, …). Like for any CSS dimension, there is no space between the unit literal and the number. The length unit is optional after the <number> 0. Many CSS properties take <length> values, such as width, margin, padding, font-size, border-width, text-shadow, … For some properties, using negative lengths is a syntax error, but for some properties, negative lengths are allowed. Interpolation Values of the <length> CSS data type can be interpolated in order to allow animations. Units Relative length units Font-relative lengths em This unit represents the calculated font-size of the element. Ex This unit represents the x-height of the element's font. Ch This unit represents the width, or more precisely the advance measure, of the glyph '0' (zero, the Unicode character U+0030) in the element's font. rem This unit is practical in creating perfectly scalable layout.
Vh vw vmin px. CSS Float Theory: Things You Should Know. The CSS Box Model. At the risk of over-repeating myself: every element in web design is a rectangular box. This was my ah-ha moment that helped me really start to understand CSS-based web design and accomplish the layouts I wanted to accomplish. We've talked about the positioning of these boxes a bit, and about their behavior. What we haven't talked about much is the box itself. How is the size of the box calculated exactly? Here is a diagram: If you are a Firebug user, you might be used to the diagram like this, which does a nice job of showing you the numbers affecting any box on the page: Notice in both examples the margin is in the white.
The size of the box itself is calculated like this: What if these values are undeclared? If padding or borders are undeclared, they are either zero (likely if you are using a css reset) or the browser default value (probably not zero especially on form elements that are commonly not reset). The Default Width of Block Level Boxes Absolute Boxes with No Width Share On. Dev.Opera — New Structural Elements in HTML5. Introduction HTML5 brings two new things to the table: new APIs that add essential new features to the open standards web development model, and new structural elements that define specific web page features with much more accurate semantics than were available in HTML 4.
You can find articles covering many of the new APIs by looking for Dev.Opera articles marked with the HTML5 tag. This article, on the other hand, focuses on the latter — we will briefly look at how the new semantic elements were chosen, what the main new features are and how they are used, how headings work in HTML5, and browser support for these new elements, including how you can support them in older browsers. The contents are as follows: Introducing HTML5 structural elements HTML4 already has a lot of semantic elements to allow you to clearly define the different features of a web page, like forms, lists, paragraphs, tables, etc. However, it does have its shortcomings.
But it could be so much better. Summary.