.app {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
  font-family: Arial, sans-serif;
}

h1 {
  color: #333;
  text-align: center;
}

h2 {
  color: #555;
}

hr {
  margin: 30px 0;
  border: 0;
  height: 1px;
  background-color: #ddd;
}

/* 计数器样式 */
.counter {
  background-color: #f5f5f5;
  padding: 20px;
  border-radius: 5px;
  text-align: center;
}

.counter button {
  margin: 0 5px;
  padding: 5px 15px;
  background-color: #4caf50;
  color: white;
  border: none;
  border-radius: 3px;
  cursor: pointer;
}

.counter button:hover {
  background-color: #45a049;
}

/* 计时器样式 */
.timer {
  background-color: #e0f7fa;
  padding: 15px;
  text-align: center;
  font-size: 18px;
  border-radius: 5px;
}

/* 待办事项列表样式 */
.todo-list {
  background-color: #f9f9f9;
  padding: 20px;
  border-radius: 5px;
}

.add-todo {
  display: flex;
  margin-bottom: 15px;
}

.add-todo input {
  flex-grow: 1;
  padding: 8px;
  border: 1px solid #ddd;
  border-radius: 3px 0 0 3px;
}

.add-todo button {
  padding: 8px 15px;
  background-color: #2196f3;
  color: white;
  border: none;
  border-radius: 0 3px 3px 0;
  cursor: pointer;
}

.add-todo button:hover {
  background-color: #0b7dda;
}

ul {
  list-style-type: none;
  padding: 0;
}

li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px;
  border-bottom: 1px solid #eee;
}

li:last-child {
  border-bottom: none;
}

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

li span {
  cursor: pointer;
}

li button {
  padding: 5px 10px;
  background-color: #f44336;
  color: white;
  border: none;
  border-radius: 3px;
  cursor: pointer;
}

li button:hover {
  background-color: #d32f2f;
} 