Detailed configuration of transition properties

Basic Concepts of Transition Properties

CSS transitions allow property values to change smoothly over a specified duration. Using the transition property, you can control which CSS properties should have transition effects, the duration of the transition, the speed curve, and the delay before the transition starts. Transitions are commonly used in user interaction scenarios, such as hover, focus, or active state changes.

.box {
  width: 100px;
  height: 100px;
  background-color: blue;
  transition: width 1s;
}

.box:hover {
  width: 200px;
}

Components of Transition Properties

The complete transition property consists of four sub-properties:

1. transition-property: Specifies the CSS properties to which the transition applies.
2. transition-duration: Defines the duration of the transition.
3. transition-timing-function: Sets the speed curve of the transition.
4. transition-delay: Sets the delay before the transition starts.

These properties can be declared individually or in shorthand form:

/* Individual declarations */
.element {
  transition-property: opacity;
  transition-duration: 0.5s;
  transition-timing-function: ease-in-out;
  transition-delay: 0.2s;
}

/* Shorthand form */
.element {
  transition: opacity 0.5s ease-in-out 0.2s;
}

Detailed Explanation of transition-property

transition-property specifies which CSS properties will have transition effects. It can be set to:

• Specific property names: e.g., width, opacity, etc.
• all: All transitionable properties.
• none: No transition effects.

.card {
  transition-property: transform, box-shadow;
}

.panel {
  transition-property: all;
}

Not all CSS properties can be transitioned. Typically, numeric properties (e.g., width, height, position, opacity) can be transitioned, while discrete properties (e.g., display) cannot.

Configuring transition-duration

transition-duration defines the duration of the transition animation, in seconds (s) or milliseconds (ms).

.btn {
  /* 0.5 seconds */
  transition-duration: 0.5s;
  
  /* 200 milliseconds */
  transition-duration: 200ms;
}

You can set different durations for multiple transition properties of an element:

.menu-item {
  transition-property: color, background-color;
  transition-duration: 0.3s, 0.5s;
}

Transition Timing Functions

transition-timing-function defines the speed curve of the transition effect. Common values include:

• ease (default): Slow start, then fast, then slow end.
• linear: Constant speed.
• ease-in: Slow start.
• ease-out: Slow end.
• ease-in-out: Slow start and end.
• cubic-bezier(n,n,n,n): Custom Bézier curve.

.ball {
  transition-timing-function: cubic-bezier(0.1, 0.7, 1.0, 0.1);
}

You can also use the steps() function to create step-based transitions:

.loader {
  transition-timing-function: steps(5, end);
}

Transition Delay

transition-delay defines the wait time before the transition effect starts:

.tooltip {
  transition-delay: 0.3s;
}

A negative delay causes the transition to start immediately but from a mid-animation state:

.slider {
  transition-delay: -0.5s;
}

Multi-Property Transition Configuration

You can configure different transition effects for different properties:

.avatar {
  transition: 
    transform 0.3s ease-out,
    opacity 0.5s linear 0.1s,
    filter 0.4s ease-in;
}

Transitions and Hardware Acceleration

Transitions for certain properties (e.g., transform and opacity) can leverage GPU acceleration:

.performance-optimized {
  transition: transform 0.3s;
  will-change: transform;
}

Transition Event Listening

JavaScript can listen for transition events:

element.addEventListener('transitionend', function(event) {
  console.log('Transition ended', event.propertyName);
});

element.addEventListener('transitionstart', function(event) {
  console.log('Transition started');
});

Combining Transitions and Animations

Transitions can be combined with CSS animations:

.component {
  transition: opacity 0.3s;
  animation: slide-in 1s forwards;
}

@keyframes slide-in {
  from { transform: translateX(-100%); }
  to { transform: translateX(0); }
}

Transitions in Responsive Design

Adjust transitions using media queries:

.nav-item {
  transition: color 0.3s;
}

@media (max-width: 768px) {
  .nav-item {
    transition: color 0.1s;
  }
}

Transition Performance Optimization

1. Avoid transitioning properties like height or margin that cause reflows.
2. Prioritize compositor-friendly properties like transform and opacity.
3. Reduce the number of properties being transitioned simultaneously.
4. Keep transition durations appropriately short.

/* Not recommended */
.element {
  transition: height 0.5s;
}

/* Recommended */
.element {
  transition: transform 0.3s;
}

Transitions and Pseudo-Elements

Transitions can also be applied to pseudo-elements:

.button::after {
  content: '';
  transition: transform 0.2s;
}

.button:hover::after {
  transform: scale(1.2);
}

Transitions and CSS Variables

Combine transitions with CSS custom properties for dynamic effects:

:root {
  --primary-color: #4285f4;
  --transition-time: 0.4s;
}

.button {
  background-color: var(--primary-color);
  transition: background-color var(--transition-time);
}

.button:hover {
  --primary-color: #34a853;
}

Cascading and Inheritance of Transitions

Transition properties follow CSS cascading rules but are not inherited:

.parent {
  transition: opacity 0.3s;
}

.child {
  /* Does not inherit transition properties */
  transition: transform 0.5s;
}

Transitions and will-change

The will-change property can hint to the browser about upcoming property changes:

.optimized {
  transition: transform 0.3s;
  will-change: transform;
}

Browser Prefixes for Transitions

While modern browsers mostly don't need prefixes, for compatibility:

.legacy-support {
  -webkit-transition: all 0.3s;
  -moz-transition: all 0.3s;
  transition: all 0.3s;
}

Transitions and JavaScript Interaction

Dynamically modify transition properties via JavaScript:

// Add transition
element.style.transition = 'transform 0.3s';

// Remove transition
element.style.transition = 'none';

// Force reflow to apply transition
void element.offsetWidth;

Transitions and SVG Elements

SVG properties can also have transitions:

circle {
  transition: r 0.5s, fill 0.3s;
}

circle:hover {
  r: 30;
  fill: #ff0000;
}

Limitations of Transitions

1. Cannot control intermediate states; only defines start and end.
2. Requires a trigger (e.g., :hover).
3. Some property transitions have poor performance.
4. Cannot create complex multi-stage animations.

Transitions and Print Styles

Disable transitions for print using @media print:

@media print {
  * {
    transition: none !important;
  }
}