How to Use CSS Background Transitions
Published: 2023-09-08 20:58:37

In this comprehensive guide, we will go over the art of implementing
CSS moving backgrounds, covering various techniques and creative ideas.

## Understanding CSS Transitions and Animations
Below are brief explanations on [CSS transitions](https://developer.mozilla.org/en-US/docs/Web/CSS/transition) and [CSS animations](https://developer.mozilla.org/en-US/docs/Web/CSS/animation).
### CSS Transitions and Animations:
CSS transitions and animations are powerful techniques that allow web developers to create smooth and visually appealing motion effects on web elements without the need for [JavaScript](https://developer.mozilla.org/en-US/docs/Web/javascript) or other scripting languages. They are essential tools for improving user experience by adding subtle or engaging animations to web interfaces.

### CSS Transitions:
Transitions enable the smooth change of property values over a specified duration. For example, you can transition properties like color, size, opacity, and more. 
Here's a basic example of a CSS transition:
The Html Code:
```htmlembedded
<!doctype html>
<html>
  <head>
    <title>CSS Transition Example</title>
    <link rel="stylesheet" href="background.css" />
  </head>
  <body>
    <div class="element"><h2>This is a text element</h2></div>
  </body>
</html>
```
The HTML code above is been used to link to an external CSS file and a `<div>` element with a class for potential styling or animation effects.
The CSS Code below:
```htmlembedded
/* Applying a transition to the color property */
.element {
  transition: color 0.3s ease;
}

.element:hover {
  color: blue; /* When hovered, the color smoothly transitions to color blue */
}
```
In the above example, when the mouse hovers over the `.element`, the text color will smoothly transition to blue over a duration of 0.3 seconds with an easing function.
The gif below show how `css transition` works with text:
![](https://hackmd.io/_uploads/rJOqbav33.gif)
gif showing text hovering animation
### CSS Animations:
Animations are more complex than transitions and allow you to define keyframes with multiple steps of the animation. This gives you greater control over the animation sequence. 
Here's a basic example of a CSS animation: 
The Html code below:
```htmlembedded=
<!DOCTYPE html>
<html>
  <head>
    <title>CSS Animation Example</title>
    <link rel="stylesheet" href="background.css" />
  </head>
  <body>
    <div class="element">This element will move 100px to the right.</div>
  </body>
</html>
```
The Css code:
```CSS
/* This define an animation named 'move' */
@keyframes move {
  0% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(100px);
  }
}

/* Apply the 'move' animation to an element */
.element {
  animation: move 1s ease infinite alternate;
}
```
From the example above, the `.element` will continuously move back and forth horizontally by 100px using the defined animation named 'move'.
Below is a gif showing how css animation works:
![](https://hackmd.io/_uploads/B1yeQpwn2.gif)
## How to create smooth and appealing motion effects
Creating Smooth and Appealing Motion Effects:

* Choose the Right Properties: Identify which properties (like opacity, position, size) you want to animate. Choose properties that make sense for your design and interaction goals.

* Easing Functions: Use appropriate easing functions to control the acceleration and deceleration of animations. Common easing functions are "ease", "ease-in", "ease-out", and "ease-in-out". You can also use cubic-bezier functions for more precise control.

* Duration and Timing: Experiment with the duration of transitions and animations. Shorter durations (around 0.2s to 0.5s) often work well for simple interactions, while longer durations can be used for more complex animations. Adjust delays to control the timing of animations.

* Subtle vs. Bold: Decide whether you want animations to be subtle enhancements or bold attention grabbers. Sometimes, less is more, and a subtle animation can have a greater impact than an overly complex one.

* Use Keyframes for Complex Animations: For intricate animations, use keyframes to define multiple steps in the animation sequence. This allows you to create sophisticated motion effects.

* Test on Multiple Devices: Ensure your animations work well on various devices and screen sizes. Responsive design is crucial to maintain a consistent user experience.

* Consider Performance: While animations can greatly enhance user experience, excessive or heavy animations can slow down a webpage. Optimize animations for performance by avoiding excessive use of heavy properties.

Remember that the goal of animations is to enhance user experience, not distract or annoy users. Thoughtful and purposeful animations can make your website or application more engaging and user-friendly.

## Creating Simple Moving Backgrounds
Let's start our journey by breathing life into static backgrounds. Animating colors, gradients, and images can instantly transform a webpage's appearance.

Below is an example of background color transition:
The Html code:
```htmlembedded=
<!DOCTYPE html>
<html>
  <head>
    <title>Background Color Transition</title>
    <link rel="stylesheet" href="background.css" />
  </head>
  <body>
    <div class="box">This is a moving background box</div>
  </body>
</html>
```
This HTML codes above creates a webpage with a box displaying the text "This is a moving background box." It references an external stylesheet "background.css" for styling, which includes background color transitions.
The CSS Code:
```Css
/* An example of background color transition */
.box {
  background-color: #3498db;
  transition: background-color 0.5s ease;
}

.box:hover {
  background-color: #9b59b6;
}
```
The CSS code above defines a ".box" element with a blue background that smoothly transitions to a purple background when hovered over, using a 0.5-second ease transition effect.

A gif showing a background color transition from blue to purple is displayed below.
![](https://hackmd.io/_uploads/ByF7rpv3n.gif)
gif showing a background color transition
### Example of gradient animation
Below is a code sample showing [gradient animation](https://www.gradient-animator.com/) with Html and CSS
The Html Code:
```htmlembedded
<!doctype html>
<html>
  <head>
    <title>Gradient Box</title>
    <link rel="stylesheet" href="background.css" />
  </head>
  <body>
    <div class="gradient-box">This is a gradient box by David Fagbuyiro.</div>
  </body>
</html>
```
The above html code includes a title and a link to an external CSS file called "background.css". It creates a webpage with a `<div>` element having the class "gradient-box", also displaying the following text which says "This is a gradient box by David Fagbuyiro" within it.

The Css code:
```CSS
.gradient-box {
  background: linear-gradient(45deg, #3498db, #e74c3c, #2ecc71);
  background-size: 200% 200%;
  animation: gradient-shift 5s ease infinite;
}

@keyframes gradient-shift {
  0% {
    background-position: 0% 50%;
  }
  100% {
    background-position: 100% 50%;
  }
}
```
The css code above creates a CSS class ".gradient-box" with a background gradient that shifts diagonally while changing colors smoothly. The animation uses [keyframes](https://developer.mozilla.org/en-US/docs/Web/CSS/@keyframes) to transition the background position from 0% to 100% horizontally over 5 seconds, creating a dynamic shifting effect.

This is a gif showing a gradient animation in action below.
![](https://hackmd.io/_uploads/r154dpw22.gif)
gif showing a gradient animation
## Implementing Interactive Backgrounds
Adding interactivity to backgrounds can greatly enhance user engagement. For example, animating the background based on cursor movement or click events can create a delightful user experience.
### Interactive background following cursor
Below is a code example showing how Interactive background following cursor is being done:
The Html Code:
```htmlembedded
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Moving Background Imag</title>
  </head>
  <link rel="stylesheet" href="background.css" />
  <body>
    <div class="interactive-bg"></div>
  </body>
</html>
```
The html code above creates a webpage with a title and a container for a moving background effect defined in an external CSS file named `background.css`.
The CSS Code Below:
```Css
.interactive-bg {
    height: 500px;
    width: 100%;
    background-image: url('Sketch.png');
    background-size: cover;
    transition: transform 0.2s ease-out;

    /* cursor movement */
    cursor: pointer;
    
    /* background change */
    &:hover {
        background-image: url('R.jpeg');
        transform: scale(1.1);
        height: 500px;
        width: 100%;
    }
}
```
The css code above defines a CSS class named `.interactive-bg` that sets a background image with transitions and hover effects. When hovered over, the background image changes to another background image named `R.jpeg` with a slight scale increase, creating an interactive visual effect.

Below is a gif demonstrating an interactive background following cursor movement:
![](https://hackmd.io/_uploads/ryiQut6sh.gif)
gif demonstrating an interactive background
## Cinematic Image Background
A cinematic image background is a type of background that is used in movies and other visual media to create a sense of depth, drama, and realism. These backgrounds are often characterized by their use of deep shadows, strong contrast, and dramatic lighting. They can also feature elements such as fog, smoke, or rain, which can help to create a more atmospheric and immersive experience.
Below is an example of cinematic image background:
The Html code:
```htmlembedded
<!doctype html>
<html>
  <head>
    <title>Moving bg Images</title>
    <link rel="stylesheet" href="background.css" />
  </head>
  <body>
    <div class="stage">
      <div class="actor"></div>
      <div class="actor"></div>
      <div class="actor"></div>
    </div>
  </body>
</html>
```
The code above creates a webpage that includes a moving background effect using CSS. It has a container with three elements representing the moving images in the background. The actual animation details are defined in an external "background.css" stylesheet which is shown below:

The CSS code below:
```CSS
body {
  background: #000;
}

.stage {
  height: 100vh;
  overflow: hidden;
  position: relative;
  width: 100vw;
}

.actor {
  animation: kenburns 10s linear infinite;
  background-size: cover;
  background-position: 50%;
  height: 100vh;
  inset: 0;
  opacity: 0;
  position: absolute;
  scale: 1.2;
  width: 100vw;
}

.actor:nth-child(1) {
  background-image: url("cinema.PNG");
}
.actor:nth-child(2) {
  animation-delay: 5s;
  background-image: url("cine.PNG");
}
.actor:nth-child(3) {
  animation-delay: 3s;
  background-image: url("Sketch.png");
}

@keyframes kenburns {
  25% {
    opacity: 1;
  }

  50% {
    opacity: 0.8;
    scale: 1;
  }

  60% {
    opacity: 0;
  }
}
```
This code above includes elements with the class "actor" that are animated in the `Ken Burns` style. These elements have background images and are positioned within a full viewport container. They gradually appear, then zoom out and fade away. The animations are timed, and the effect gives a dynamic touch to the images.
Below is a gif output of the above html and css code:
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/v27apvol7xgb7jizvf1e.gif)
Image backround transition

## Optimization and Performance Considerations
While moving backgrounds add a dynamic touch, it's important to consider performance implications. Optimize animations to ensure smooth experiences without compromising loading times.

### To optimize animations:
1. Use hardware-accelerated properties like transform and opacity.
2. Limit the use of heavy animations on mobile devices.
3. Use the [will-change](https://developer.mozilla.org/en-US/docs/Web/CSS/will-change) property to hint at upcoming animations.


Below is a code sample to optimize animation by Using `will-change`.
The `Html` Code:
```htmlembedded=
<!DOCTYPE html>
<html>
<head>
<title>Animation Optimization</title>
<link rel="stylesheet" href="background.css">
</head>
<body>
<div class="optimized-animation">
  <h1>This is an optimized animation</h1>
</div>
</body>
</html>
```
The html code above creates a webpage with a title and link it to an external stylesheet file which displays an optimized animation heading within a styled `div`.

The Css code below:
```css
/* Using will-change for animation optimization */

.optimized-animation {
  will-change: transform, opacity;
  animation: slide-in 1.5s ease-in-out;
}
```
The css code above creates a CSS class called `optimized-animation` for a smoother animation by prepping the `transform` and `opacity` changes using `will-change`, then applying a sliding animation effect to it.

Below is a gif showing the effect and how the h1 tag slides in:
![](https://hackmd.io/_uploads/rJs449psn.gif)
gif showing `will-change` effect

## Advanced Techniques and Inspiration
here are some advanced techniques and inspiration for creating moving backgrounds with CSS:
### Pushing the boundaries with advanced CSS moving background techniques
* Using multiple background images: You can use multiple background images to create a more complex and dynamic effect. For example, you could use one image for the background and another image for the foreground, and then animate the two images in different ways.
* Using CSS gradients: CSS gradients can be used to create smooth and seamless transitions between different colors. This can be used to create a variety of effects, such as a background that fades from one color to another, or a background that changes color as the user scrolls down the page.
* Using CSS animations: CSS animations can be used to create moving backgrounds that are more interactive and engaging. For example, you could animate a background image to move across the screen, or you could animate a background color to change over time.
### Drawing inspiration from real-world examples
There are many great examples of moving backgrounds that have been created with CSS. Here are a few examples to get you inspired:

1. The CSS3 Generator: This website uses CSS to create a variety of moving backgrounds, including backgrounds that fade, scroll, and animate.
![](https://hackmd.io/_uploads/r1tjyN3ih.jpg)
image source: [Css3 generator website](https://chrome.google.com/webstore/detail/css3-generator/dmlgmehijaodgkkooghkknjjkddahmej?hl=en-GB)

2. The Parallax Effect: This effect can be created through the use of different background images for various sections of the page. The background graphics flow at varying speeds as the viewer scrolls down the page, creating a sense of depth.
![](https://hackmd.io/_uploads/H1n6eE3i2.png)
Image source: [Parallax Effect webswebsite](https://0707.agency/_nuxt/image/bfb866.webp) 

3. The Fluid Background: This effect is created by using a CSS gradient that is responsive to the user's screen size. As the user's screen size changes, the gradient changes, creating a fluid and dynamic effect.
![](https://hackmd.io/_uploads/Sy0XZN2i3.png)
Image source: [Fluid Backgroud website](https://www.vecteezy.com/vector-art/14562646-purple-liquid-background-in-3d-style-web-design-liquid-color-business-website-template-flow-and-fluid-background-eps-10-vector)

## Conclusion
The Fluid Background: This effect is created by using a CSS gradient that is responsive to the user's screen size. As the user's screen size changes, the gradient changes, creating a fluid and dynamic effect.