body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 20px;
  background-color: #f4f4f4;
}

body * {
  box-sizing: border-box;
}

.container {
  max-width: 600px;
  margin: 0 auto;
  background: white;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

h1 {
  margin-top: 0;
  color: #333;
}

#todoInput {
  width: 70%;
  padding: 10px;
  font-size: 16px;
  border: 1px solid #ddd;
  border-radius: 4px;
}

#addBtn {
  width: 25%;
  padding: 10px;
  font-size: 16px;
  background-color: #4CAF50;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

#addBtn:hover {
  background-color: #45a049;
}

#todoList {
  list-style: none;
  padding: 0;
  margin-top: 20px;
}

#todoList li {
  padding: 12px;
  background-color: #f9f9f9;
  margin-bottom: 8px;
  border-radius: 4px;
  border-left: 4px solid #4CAF50;
}