Create A Dark/Light Mode Switch with CSS Variables

Create A Dark/Light Mode Switch with CSS Variables

<strong>Giving your users a way to customise the interface to their preference is a huge win for user experience. Here we are going to provide the user with a simple switch to toggle between dark mode and light mode and we will also try to remember their preference for future visits.</strong>

Giving your users a way to customise the interface to their preference is a huge win for user experience. Here we are going to provide the user with a simple switch to toggle between dark mode and light mode and we will also try to remember their preference for future visits.

Let’s begin!

If you don’t have a website of your own to which you wish to add this functionality, use this demo website to follow along.

Adding the CSS

We will be adding CSS custom properties also known as CSS variables, which we can reference and modify throughout the document. If you wish to read more about custom properties you can read on MDN.

Here’s the tldr; version -

Custom properties (sometimes referred to as CSS variables or cascading variables) are entities defined by CSS authors that contain specific values to be reused throughout a document. They are set using custom property notation (e.g., --main-color: black;) and are accessed using the var() function (e.g., color: var(–main-color);)

First, we’ll add our light or default mode css variables to the :root pseudo class. It matches with the root element in your document tree, generally the <html> tag. We will use :root because we want to avail the variables globally.

:root {
    --primary-color: #302AE6;
    --secondary-color: #536390;
    --font-color: #424242;
    --bg-color: #fff;
    --heading-color: #292922;
}

Second, we’ll add our dark mode css variables.

[data-theme="dark"] {
--primary-color: #9A97F3;
--secondary-color: #818cab;
--font-color: #e1e1ff;
--bg-color: #161625;
--heading-color: #818cab;
}

What is [data-theme="dark"]? This means we are referencing a data attribute called data-theme with a value “dark”. We will find the use of it in a while.

Then, we can reference these variables in our stylesheets like so-

body {
background-color: var(--bg-color);
color: var(--font-color);

/*other styles*/
.....

}

h1 {
color: var(--secondary-color);

/*other styles*/
.....

}

a {
color: var(--primary-color);

/*other styles*/
.....

}

Adding the HTML “toggle switch markup”

This is essentially just a checkbox, however we will add some additional markup to style like a toggle switch. I referenced the styles from this codepen.

<div class="theme-switch-wrapper">
<label class="theme-switch" for="checkbox">
<input type="checkbox" id="checkbox" />
<div class="slider round"></div>
</label>
<em>Enable Dark Mode!</em>
</div>

/Simple css to style it like a toggle switch/
.theme-switch-wrapper {
display: flex;
align-items: center;

em {
margin-left: 10px;
font-size: 1rem;
}
}
.theme-switch {
display: inline-block;
height: 34px;
position: relative;
width: 60px;
}

.theme-switch input {
display:none;
}

.slider {
background-color: #ccc;
bottom: 0;
cursor: pointer;
left: 0;
position: absolute;
right: 0;
top: 0;
transition: .4s;
}

.slider:before {
background-color: #fff;
bottom: 4px;
content: "";
height: 26px;
left: 4px;
position: absolute;
transition: .4s;
width: 26px;
}

input:checked + .slider {
background-color: #66bb6a;
}

input:checked + .slider:before {
transform: translateX(26px);
}

.slider.round {
border-radius: 34px;
}

.slider.round:before {
border-radius: 50%;
}

Adding the JavaScript

The final part is to add the bit of JavaScript to tie it all together.

We have 3 tasks in hand-

  • Add event handlers to handle accordingly the check/uncheck event of toggle-switch
  • Store the user preference for future visits
  • Check for saved user preference, if any, on load of the website

Adding the event handlers


const toggleSwitch = document.querySelector('.theme-switch input[type="checkbox"]');

function switchTheme(e) {
if (e.target.checked) {
document.documentElement.setAttribute('data-theme', 'dark');
}
else {
document.documentElement.setAttribute('data-theme', 'light');
}
}

toggleSwitch.addEventListener('change', switchTheme, false);

Remember, the data-theme attribute we referenced in CSS above, this is where it’s getting added to our root element.

Store the user preference for future visits

We will use browser’s localStorage to store the user preference.

Let’s modify our switchTheme function -

function switchTheme(e) {
if (e.target.checked) {
document.documentElement.setAttribute('data-theme', 'dark');
localStorage.setItem('theme', 'dark'); //add this
}
else {
document.documentElement.setAttribute('data-theme', 'light');
localStorage.setItem('theme', 'light'); //add this
}
}

Check for saved user preference, if any, on load of the website

We will check if the theme preference is saved, if yes then we will, accordingly-

  • set our data-theme attribute
  • check/uncheck our toggle-switch checkbox

const currentTheme = localStorage.getItem('theme') ? localStorage.getItem('theme') : null;

if (currentTheme) {
document.documentElement.setAttribute('data-theme', currentTheme);

if (currentTheme === 'dark') {
    toggleSwitch.checked = true;
}

}

That’s it! Check out the full demo below.

I recently added this to [my website](https://ananyaneogi.com), so check that out as well, maybe!Pro-Tip: How to decide on the color scheme?

My suggestion is to stay in the same spectrum of your primary or brand color and generate a palette out of it. Use the darkest shade from the palette as the background color and the lighter shades as font colors when in dark mode. I used this color shades generator for generating my color palette.

Even if you don’t end up using the exact colors generated, it is still a good place to start. Even I ended up fine tuning the colors I ultimately used.

Originally published by Ananya Neogi at https://dev.to/ananyaneogi/create-a-dark-light-mode-switch-with-css-variables-34l8

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HTML 5 Tutorial: How to create a table using HTML tags and Stylesheet (CSS)

HTML 5 Tutorial: How to create a table using HTML tags and Stylesheet (CSS)

In this article, we want to show you how to create a table using HTML tags and Stylesheet (CSS). HTML table may vary depends on data and style requirements. Sometimes, in the real application, we use an HTML table as a layout of the Email template in HTML format.

In this article, we want to show you how to create a table using HTML tags and Stylesheet (CSS). HTML table may vary depends on data and style requirements. Sometimes, in the real application, we use an HTML table as a layout of the Email template in HTML format.

HTML Table uses to represent tabular data like in the Excel Application and arrange the layout of the Web View.

There are some common HTML tags that use by HTML table:

Before start practicing HTML 5 table, make sure all

tag put inside complete and tag.

<!DOCTYPE html>
<html>
 <head>
  <title>Basic HTML Table</title>
 </head>
 <body>
  <table></table>
 </body>
</html>

Basic HTML Table

Here is an example of a basic HTML table or common use of the above HTML tags to define or create a table.

<table>
 <tr>
  <th>No.</th>
  <th>Full Name</th>
  <th>Position</th>
  <th>Salary</th>
 </tr>
 <tr>
  <td>1</td>
  <td>Bill Gates</td>
  <td>Founder Microsoft</td>
  <td><table>
 <tr>
  <th>No.</th>
  <th>Full Name</th>
  <th>Position</th>
  <th>Salary</th>
 </tr>
 <tr>
  <td>1</td>
  <td>Bill Gates</td>
  <td>Founder Microsoft</td>
  <td>$1000</td>
 </tr>
 <tr>
  <td>2</td>
  <td>Steve Jobs</td>
  <td>Founder Apple</td>
  <td>$1200</td>
 </tr>
 <tr>
  <td>3</td>
  <td>Larry Page</td>
  <td>Founder Google</td>
  <td>$1100</td>
 </tr>
 <tr>
  <td>4</td>
  <td>Mark Zuckeberg</td>
  <td>Founder Facebook</td>
  <td>$1300</td>
 </tr>
</table>
000</td>
 </tr>
 <tr>
  <td>2</td>
  <td>Steve Jobs</td>
  <td>Founder Apple</td>
  <td><table>
 <tr>
  <th>No.</th>
  <th>Full Name</th>
  <th>Position</th>
  <th>Salary</th>
 </tr>
 <tr>
  <td>1</td>
  <td>Bill Gates</td>
  <td>Founder Microsoft</td>
  <td>$1000</td>
 </tr>
 <tr>
  <td>2</td>
  <td>Steve Jobs</td>
  <td>Founder Apple</td>
  <td>$1200</td>
 </tr>
 <tr>
  <td>3</td>
  <td>Larry Page</td>
  <td>Founder Google</td>
  <td>$1100</td>
 </tr>
 <tr>
  <td>4</td>
  <td>Mark Zuckeberg</td>
  <td>Founder Facebook</td>
  <td>$1300</td>
 </tr>
</table>
200</td>
 </tr>
 <tr>
  <td>3</td>
  <td>Larry Page</td>
  <td>Founder Google</td>
  <td><table>
 <tr>
  <th>No.</th>
  <th>Full Name</th>
  <th>Position</th>
  <th>Salary</th>
 </tr>
 <tr>
  <td>1</td>
  <td>Bill Gates</td>
  <td>Founder Microsoft</td>
  <td>$1000</td>
 </tr>
 <tr>
  <td>2</td>
  <td>Steve Jobs</td>
  <td>Founder Apple</td>
  <td>$1200</td>
 </tr>
 <tr>
  <td>3</td>
  <td>Larry Page</td>
  <td>Founder Google</td>
  <td>$1100</td>
 </tr>
 <tr>
  <td>4</td>
  <td>Mark Zuckeberg</td>
  <td>Founder Facebook</td>
  <td>$1300</td>
 </tr>
</table>
100</td>
 </tr>
 <tr>
  <td>4</td>
  <td>Mark Zuckeberg</td>
  <td>Founder Facebook</td>
  <td><table>
 <tr>
  <th>No.</th>
  <th>Full Name</th>
  <th>Position</th>
  <th>Salary</th>
 </tr>
 <tr>
  <td>1</td>
  <td>Bill Gates</td>
  <td>Founder Microsoft</td>
  <td>$1000</td>
 </tr>
 <tr>
  <td>2</td>
  <td>Steve Jobs</td>
  <td>Founder Apple</td>
  <td>$1200</td>
 </tr>
 <tr>
  <td>3</td>
  <td>Larry Page</td>
  <td>Founder Google</td>
  <td>$1100</td>
 </tr>
 <tr>
  <td>4</td>
  <td>Mark Zuckeberg</td>
  <td>Founder Facebook</td>
  <td>$1300</td>
 </tr>
</table>
300</td>
 </tr>
</table>

Output:

As a default, HTML 5 table not defined with border, you should add the border manually in each table cells.

HTML Table with Border

To add a basic border to HTML 5 table, simply add this style attribute in

tag.

<table style="border: solid 1px #aaa999;">

Output:

As you can see, Table Border only draw lines to the table only and cells left borderless. To make border for all cells, add style attribute to all and all .

<table style="border: solid 1px #aaa999;">
 <tr>
  <th style="border: solid 1px #aaa999;">No.</th>
  <th style="border: solid 1px #aaa999;">Full Name</th>
  <th style="border: solid 1px #aaa999;">Position</th>
  <th style="border: solid 1px #aaa999;">Salary</th>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">1</td>
  <td style="border: solid 1px #aaa999;">Bill Gates</td>
  <td style="border: solid 1px #aaa999;">Founder Microsoft</td>
  <td style="border: solid 1px #aaa999;"><table style="border: solid 1px #aaa999;">
 <tr>
  <th style="border: solid 1px #aaa999;">No.</th>
  <th style="border: solid 1px #aaa999;">Full Name</th>
  <th style="border: solid 1px #aaa999;">Position</th>
  <th style="border: solid 1px #aaa999;">Salary</th>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">1</td>
  <td style="border: solid 1px #aaa999;">Bill Gates</td>
  <td style="border: solid 1px #aaa999;">Founder Microsoft</td>
  <td style="border: solid 1px #aaa999;">$1000</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">2</td>
  <td style="border: solid 1px #aaa999;">Steve Jobs</td>
  <td style="border: solid 1px #aaa999;">Founder Apple</td>
  <td style="border: solid 1px #aaa999;">$1200</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">3</td>
  <td style="border: solid 1px #aaa999;">Larry Page</td>
  <td style="border: solid 1px #aaa999;">Founder Google</td>
  <td style="border: solid 1px #aaa999;">$1100</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">4</td>
  <td style="border: solid 1px #aaa999;">Mark Zuckeberg</td>
  <td style="border: solid 1px #aaa999;">Founder Facebook</td>
  <td style="border: solid 1px #aaa999;">$1300</td>
 </tr>
</table>
000</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">2</td>
  <td style="border: solid 1px #aaa999;">Steve Jobs</td>
  <td style="border: solid 1px #aaa999;">Founder Apple</td>
  <td style="border: solid 1px #aaa999;"><table style="border: solid 1px #aaa999;">
 <tr>
  <th style="border: solid 1px #aaa999;">No.</th>
  <th style="border: solid 1px #aaa999;">Full Name</th>
  <th style="border: solid 1px #aaa999;">Position</th>
  <th style="border: solid 1px #aaa999;">Salary</th>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">1</td>
  <td style="border: solid 1px #aaa999;">Bill Gates</td>
  <td style="border: solid 1px #aaa999;">Founder Microsoft</td>
  <td style="border: solid 1px #aaa999;">$1000</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">2</td>
  <td style="border: solid 1px #aaa999;">Steve Jobs</td>
  <td style="border: solid 1px #aaa999;">Founder Apple</td>
  <td style="border: solid 1px #aaa999;">$1200</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">3</td>
  <td style="border: solid 1px #aaa999;">Larry Page</td>
  <td style="border: solid 1px #aaa999;">Founder Google</td>
  <td style="border: solid 1px #aaa999;">$1100</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">4</td>
  <td style="border: solid 1px #aaa999;">Mark Zuckeberg</td>
  <td style="border: solid 1px #aaa999;">Founder Facebook</td>
  <td style="border: solid 1px #aaa999;">$1300</td>
 </tr>
</table>
200</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">3</td>
  <td style="border: solid 1px #aaa999;">Larry Page</td>
  <td style="border: solid 1px #aaa999;">Founder Google</td>
  <td style="border: solid 1px #aaa999;"><table style="border: solid 1px #aaa999;">
 <tr>
  <th style="border: solid 1px #aaa999;">No.</th>
  <th style="border: solid 1px #aaa999;">Full Name</th>
  <th style="border: solid 1px #aaa999;">Position</th>
  <th style="border: solid 1px #aaa999;">Salary</th>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">1</td>
  <td style="border: solid 1px #aaa999;">Bill Gates</td>
  <td style="border: solid 1px #aaa999;">Founder Microsoft</td>
  <td style="border: solid 1px #aaa999;">$1000</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">2</td>
  <td style="border: solid 1px #aaa999;">Steve Jobs</td>
  <td style="border: solid 1px #aaa999;">Founder Apple</td>
  <td style="border: solid 1px #aaa999;">$1200</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">3</td>
  <td style="border: solid 1px #aaa999;">Larry Page</td>
  <td style="border: solid 1px #aaa999;">Founder Google</td>
  <td style="border: solid 1px #aaa999;">$1100</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">4</td>
  <td style="border: solid 1px #aaa999;">Mark Zuckeberg</td>
  <td style="border: solid 1px #aaa999;">Founder Facebook</td>
  <td style="border: solid 1px #aaa999;">$1300</td>
 </tr>
</table>
100</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">4</td>
  <td style="border: solid 1px #aaa999;">Mark Zuckeberg</td>
  <td style="border: solid 1px #aaa999;">Founder Facebook</td>
  <td style="border: solid 1px #aaa999;"><table style="border: solid 1px #aaa999;">
 <tr>
  <th style="border: solid 1px #aaa999;">No.</th>
  <th style="border: solid 1px #aaa999;">Full Name</th>
  <th style="border: solid 1px #aaa999;">Position</th>
  <th style="border: solid 1px #aaa999;">Salary</th>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">1</td>
  <td style="border: solid 1px #aaa999;">Bill Gates</td>
  <td style="border: solid 1px #aaa999;">Founder Microsoft</td>
  <td style="border: solid 1px #aaa999;">$1000</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">2</td>
  <td style="border: solid 1px #aaa999;">Steve Jobs</td>
  <td style="border: solid 1px #aaa999;">Founder Apple</td>
  <td style="border: solid 1px #aaa999;">$1200</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">3</td>
  <td style="border: solid 1px #aaa999;">Larry Page</td>
  <td style="border: solid 1px #aaa999;">Founder Google</td>
  <td style="border: solid 1px #aaa999;">$1100</td>
 </tr>
 <tr>
  <td style="border: solid 1px #aaa999;">4</td>
  <td style="border: solid 1px #aaa999;">Mark Zuckeberg</td>
  <td style="border: solid 1px #aaa999;">Founder Facebook</td>
  <td style="border: solid 1px #aaa999;">$1300</td>
 </tr>
</table>
300</td>
 </tr>
</table>

If you want a simple coding without writing a style for each cells, use

CSS Units - Which ones to use and which to stop using! - HTML CSS Tutorial

In this tutorial, we'll cover all the CSS units, and, most importantly, which ones to use (and which NOT to use) for which situations.

In web development, css units are often confusing as there are just many options. And, many css units - like px vs em vs rem, all seem to get the job done at times. But some are simply better than others and there are very good reasons why.

================

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