body {
  font-family: Arial, sans-serif;
  background-color: #f5f5f5;
  margin: 0;
  padding: 20px;
}

.todo-app {
  max-width: 400px;
  margin: 0 auto;
  background-color: #fff;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.input-container {
  display: flex;
  margin-bottom: 20px;
}

#todo-input {
  flex: 1;
  padding: 8px;
  border: 1px solid #ccc;
  border-radius: 4px;
}

#add-button {
  margin-left: 8px;
  padding: 8px 12px;
  border: none;
  background-color: #007bff;
  color: #fff;
  border-radius: 4px;
  cursor: pointer;
}

#add-button:hover {
  background-color: #0056b3;
}

#todo-list {
  list-style-type: none;
  padding: 0;
}

#todo-list li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 0;
  border-bottom: 1px solid #e0e0e0;
}

#todo-list li.completed span {
  text-decoration: line-through;
  color: #888;
}

#todo-list li span {
  cursor: pointer;
}

#todo-list li button {
  border: none;
  background: transparent;
  color: #dc3545;
  cursor: pointer;
}

#todo-list li button:hover {
  text-decoration: underline;
}