Welcome, eager learners! In today's exciting web design lesson, we're diving into CSS positioning, transitions, and animations. These dynamic enhancements breathe life into sterile web pages, creating vibrant and interactive digital experiences. Ready to jump in? Let's go!
In CSS, the position
property controls an element's location on a web page. Here’s what different position
values do:
- Static: By default, an element is static, occupying its natural place in the flow of the document.
- Relative: A relative element can move from its natural place based on the
top
,right
,bottom
,left
properties. Other elements still behave as if it's in its original position. - Absolute: The position is set relative to the nearest positioned ancestor, not from the top of the page.
- Fixed: The element's position is "fixed" to the viewport, so it stays in the same place even when you scroll the page.
The top
, right
, bottom
, and left
properties are used in conjunction with all positioning types except static. For relative positioning, these properties will "push" the element from its normal position to down
, left
, up
, and right
respectively. But for absolute and fixed, they position the element at a specific distance from the respectively top
, right
, bottom
, and left
edge of its containing element.
Here’s an illustration in code:
Note that the 7-symbol words in the border
properties are hexadecimal notations of some colors.
Transitions in CSS let you gradually change property values, creating a smooth effect. By specifying the transition parameters like so:
we require to change the property <transition-property>
within <transition-duration>
amount of time (typically accepts values in seconds (s) or milliseconds (ms), e.g., 2s
or 2000ms
) using the function <transition-timing-function>
.
The timing function can have the following values:
- 'ease' (starts slow, increases speed, then ends slow)
- 'linear' (equal speed)
- 'ease-in' (starts slow)
- 'ease-out' (ends slow)
- 'ease-in-out' (starts slow and ends slow).
The difference between 'ease' and 'ease-in-out' is that 'ease' speeds up sooner. For example, consider a button that slowly changes from blue to green when hovered over.
:hover
is called a pseudoclass, that applies a specific style to an element when hovered over. Do not worry if you don’t understand it now. We’ll go into more detail later on.
While transitions offer basic effects, animations
allow you to define multiple style changes at various points, creating complex visual effects. Like transitions, they go from one CSS style to another but offer much more control.
Animations are defined using keyframes
. Here’s an animation example:
Let's take a closer look at the following line:
This is a keyframe. 0%
represents the starting point of one cycle of the animation (100%
represents the ending point of the cycle, and any percentage in between represents the corresponding point in time within that cycle). The accompanying rule set specifies the CSS property (or properties) that are to be applied at this particular moment of the animation. In this case, the CSS left
property is set to 0px
, positioning the box at the left edge of its containing element when the animation starts. It's important to note that multiple properties could be defined within these braces, allowing multiple style changes to be animated simultaneously.
When adding an already defined animation to the element, we use the following property:
<animation-name>
is the name of the animation. <animation-duration>
and <animation-timing-function>
are similar to the transition parameters. <animation-iteration-count>
specifies how many times animation repeats, type 'infinite' for endless repetition.
In some scenarios, you might want your animation to rotate its direction every time it completes a cycle. In that case you add a parameter called <animation-direction>
to your animation
property with the value alternate
in the end. Specifically, the above code can be rewritten in the following way:
Great job! By mastering CSS positioning, transitions, and animations, you have taken a significant step forward. Now, get ready for practice exercises to reinforce your knowledge. Keep practicing, and soon, you'll intuitively create visually stunning web designs. Let's proceed!
