Adding Dark and Light Theme Support in React/Next.js

Overview

In this guide, we'll walk you through the steps to add dark and light theme support to a React or Next.js application. This approach will allow users to toggle between themes, and the UI will update accordingly.

Prerequisites

Basic knowledge of React or Next.js.
A React or Next.js project set up.

Steps to Implement Dark and Light Themes

1.Creating a Theme Toggle Component

Next, create a component that allows users to switch between themes. This component will include a button that toggles the theme state and a menu that lets users select their preferred theme.

import React, { useState } from 'react';
import { FaMoon, FaSun } from 'react-icons/fa';

function ThemeToggle() {
  const [menuOpen, setMenuOpen] = useState(false);
  const [theme, setTheme] = useState('dark');

  const toggleMenu = () => {
    setMenuOpen(!menuOpen);
  };
  const handleThemeChange = (mode) => {
    setTheme(mode);
    setMenuOpen(false);
  };
  useEffect(() => {
    document.body.className = theme + '-mode';

  }, [theme]);

  return (
    <li className="m-auto mx-3" role="button">
      <div className="theme-toggle">
        <button className="theme-toggle-btn" onClick={toggleMenu}>
          {theme === 'dark' ? <FaMoon /> : <FaSun />}
        </button>
        {menuOpen && (
          <div className="theme-menu">
            <p className="theme-title">Toggle Dark Mode</p>
            <ul>
              <li
                onClick={() => handleThemeChange('dark')}
                className={theme === 'dark' ? 'active' : ''}
              >
                <FaMoon /> Dark Mode
              </li>
              <li
                onClick={() => handleThemeChange('light')}
                className={theme === 'light' ? 'active' : ''}
              >
                <FaSun /> Light Mode
              </li>
            </ul>
          </div>
        )}
      </div>
    </li>
  );
}

export default ThemeToggle;

2. Defining Theme-Specific CSS Variables

Define CSS variables for both dark and light themes in your index.css or App.css file. These variables will control the styling of the entire application based on the active theme.

/* Default Theme Variables */
:root {
  --white-color: #ffff;
  --background-color: black;
  --text-color: #ffff;
  --games-text: #452c88;
  --games-text-2: #60882c;
  --game-bg-card: #252331;
  --card-wrapper-color: #252331;
  --custom-input-bg: #14131b;
  --siderbar-bg: #1a1923;
  --profile-badge-color: #252364;
  --card-header-bg: #032b53;
  --theme-color: #df1b47;
  --table-row-bg-color: #1e1d29;
  --table-row-header-color: #252364;
  --button-bg-color: #252364;
  --dark-light-bg-color: #353940;
}

/* Dark Theme */
body.dark-mode {
  --white-color: #ffff;
  --background-color: black;
  --text-color: #ffff;
  --game-bg-card: #252331;
  --card-wrapper-color: #252331;
  --custom-input-bg: #14131b;
  --siderbar-bg: #1a1923;
  --profile-badge-color: #252364;
  --card-header-bg: #032b53;
  --table-row-bg-color: #1e1d29;
  --table-row-header-color: #252364;
  --button-bg-color: #252364;
  --dark-light-bg-color: #353940;
}

/* Light Theme */
body.light-mode {
  --white-color: #ffff;
  --background-color: rgb(253, 251, 251);
  --text-color: #0f0e0ecc;
  --game-bg-card: #eae8eb;
  --custom-input-bg: #e0e0e0;
  --card-wrapper-color: #e1e0e6;
  --custom-input-bg: #e6e6e6;
  --siderbar-bg: #e5e5e5;
  --profile-badge-color: #e64b4b;
  --card-header-bg: #a6cbf0;
  --table-row-bg-color: #ffffff;
  --table-row-header-color: #f2f4f6;
  --button-bg-color: #df1b47;
  --dark-light-bg-color: #c5c1c1;
}