body {
  font-family: Arial, Helvetica, sans-serif;
  background-color: #f4f4f4;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

.container {
  background-color: white;
  border-radius: 8px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
  width: 300px;
  padding: 20px;
  text-align: center;
}

h1 {
  font-size: 24px;
  margin-bottom: 20px;
  color: #333;
}

.input-section {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

#task-input {
  flex: 1;
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 4px;
  transition: border-color 0.3s;
}

#task-input:focus {
  border-color: #28a745;
  outline: none;
}

#add-task-btn {
  background-color: #28a745;
  color: white;
  border: none;
  padding: 10px;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

#add-task-btn:hover {
  background-color: #218838;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
  transform: scale(1.05);
}

#task-list {
  list-style: none;
  padding: 0;
}

.task-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 4px;
  margin-bottom: 10px;
  transition: background-color 0.3s ease;
}

.task-item.completed {
  background-color: #d4edda;
  text-decoration: line-through;
  color: #155724;
}

.task-item button {
  background-color: #dc3545;
  color: white;
  border: none;
  padding: 5px 10px;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

.task-item button:hover {
  background-color: #c82333;
}