Building a Todo App with Theme Toggle Using React

├── public
├── src
│   ├── components
│   │   ├── TodoList.jsx
│   │   ├── TodoItem.jsx
│   ├── App.jsx
│   ├── App.css
│   ├── index.js
│   └── index.css
├── package.json
└── README.md

import { useState, useEffect } from "react";
import TodoItem from "./TodoItem";

const TodoList = () => {
  const [task, setTask] = useState("");
  const [tasks, setTasks] = useState([]);

  useEffect(() => {
    const savedTasks = JSON.parse(localStorage.getItem("tasks")) || [];
    setTasks(savedTasks);
  }, []);

  useEffect(() => {
    localStorage.setItem("tasks", JSON.stringify(tasks));
  }, [tasks]);

  const addTask = () => {
    if (task.trim()) {
      setTasks([...tasks, { text: task, completed: false }]);
      setTask("");
    }
  };

  const toggleCompletion = (index) => {
    const newTasks = tasks.map((t, i) =>
      i === index ? { ...t, completed: !t.completed } : t
    );
    setTasks(newTasks);
  };

  const deleteTask = (index) => {
    const newTasks = tasks.filter((_, i) => i !== index);
    setTasks(newTasks);
  };

  return (
    <div classname="todo-list">
      <h1 id="Todo-List">Todo List</h1>
      <input type="text" value="{task}" onchange="{(e)"> setTask(e.target.value)}
        placeholder="Add a new task"
      />
      <button onclick="{addTask}">Add Task</button>
      <ul>
        {tasks.map((t, index) => (
          <todoitem key="{index}" task="{t}" index="{index}" togglecompletion="{toggleCompletion}" deletetask="{deleteTask}"></todoitem>
        ))}
      </ul>
    </div>
  );
};

export default TodoList;

const TodoItem = ({ task, index, toggleCompletion, deleteTask }) => {
  return (
    

import  { useState } from "react";
import "./App.css";
import TodoList from './components/TodoList';
import sun from "./assets/images/icon-sun.svg";
import moon from "./assets/images/icon-moon.svg";

const App = () => {
  const [isLightTheme, setIsLightTheme] = useState(false);

  const toggleTheme = () => {
    setIsLightTheme(!isLightTheme);
  };

  return (
    <div classname="{isLightTheme" :>
      <div classname="app">
        <div classname="header">
          <div classname="title">
            <h1 id="TODO">TODO</h1>
          </div>
          <div classname="mode" onclick="{toggleTheme}">
            <img src="%7BisLightTheme" moon : sun alt="Building a Todo App with Theme Toggle Using React">
          </div>
        </div>
        <todo></todo>
        <div classname="footer">
        <p>Made with ❤️ by Abhishek Gurjar</p>
      </div>
      </div>

    </div>
  );
};

export default App;

* {
  box-sizing: border-box;
}
body {
  margin: 0;
  padding: 0;
  font-family: Josefin Sans, sans-serif;
}

.app {
  width: 100%;
  height: 100vh;
  background-color: #161722;
  color: white;
  background-image: url(./assets//images/bg-desktop-dark.jpg);
  background-repeat: no-repeat;
  background-size: contain;
  background-position-x: center;
  background-position-y: top;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  flex-direction: column;
}
.header {
  width: 350px;
  margin-top: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.title h1 {
  font-size: 30px;
  letter-spacing: 7px;
}
.mode {
  display: flex;
  align-items: center;
  justify-content: center;
}
.mode img {
  width: 22px;
}

.todo {
  width: 350px;
  flex-direction: column;
  display: flex;
  align-items: center;
  justify-content: flex-start;
}
.input-box {
  border-bottom: 1px solid white;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: #25273c;
  width: 100%;
  gap: 10px;
  padding: 8px;
  border-radius: 10px;
}
.check-circle {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 1px solid white;
  display: flex;
  align-items: center;
  justify-content: center;
  background-image: linear-gradient(to right,hsl(230, 50%, 20%) , hsl(280, 46%, 28%));
}

.input-task {
  width: 90%;
  border: none;
  color: white;
  background-color: #25273c;
}
.input-task:focus {
  outline: none;
}
.todo-list {

  margin-top: 20px;
  width: 350px;
  background-color: #25273c;
}
.todo-box {

  margin-inline: 15px;
  margin-block: 10px;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 15px;
}
.todo-box .cross{
width: 14px;
}
.details {
  margin-bottom: 40px;
border-bottom: 1px solid white;
  width: 350px;
  display: flex;
  align-items: center;
  justify-content: space-evenly;
  background-color: #25273c;
  font-size: 12px;
  padding: 12px;
  border-bottom-right-radius: 7px;
  border-bottom-left-radius: 7px;
}

.details .clickBtn{
  cursor: pointer;

}
.details .clickBtn:hover{
color: #3074fd;

}


/* //light Theme  */


.light-theme .app {
  background-color: #fff;
  color: #000;
  background-image: url(./assets//images/bg-desktop-light.jpg);
}

.light-theme .header {
color: white;
}

.light-theme .input-box{
  background-color: white;
  color: black;
  border-bottom: 1px solid black;
}
.light-theme input{
  background-color: white;
  color: black;
}
.light-theme .check-circle{
  border:1px solid black;

}
.light-theme  .todo-list{
  background-color: white;
  color: black;
}
.light-theme .details{
  border-bottom: 1px solid black;
  background-color: white;
  color: black;
}

.footer{
 margin: 40px;
}

git clone https://github.com/abhishekgurjar-in/todo_list.git
cd todo-list
npm install
npm start