不要使用Tkinter，使用pyqt5爱实现

好的，以下是使用PyQt5实现的悬浮窗口倒计时工具的示例代码：

import sys
from PyQt5.QtCore import QTimer
from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QVBoxLayout, QLineEdit, QPushButton
import time
import pyttsx3

class CountdownTimer(QWidget):
    def __init__(self):
        super().__init__()

        self.countdown_sec = 0
        self.remaining_sec = 0
        self.timer_running = False

        self.label_time = QLabel("00:00:00", self)
        self.label_time.setStyleSheet("font-size: 24px;")
        
        self.entry_time = QLineEdit(self)
        self.entry_time.setPlaceholderText("请输入倒计时时间（秒）")
        
        self.button_start = QPushButton("开始", self)
        self.button_pause = QPushButton("暂停", self)
        self.button_pause.setEnabled(False)
        self.button_reset = QPushButton("重置", self)
        self.button_reset.setEnabled(False)
        self.button_stop = QPushButton("停止", self)
        self.button_stop.setEnabled(False)

        layout = QVBoxLayout()
        layout.addWidget(self.label_time)
        layout.addWidget(self.entry_time)
        layout.addWidget(self.button_start)
        layout.addWidget(self.button_pause)
        layout.addWidget(self.button_reset)
        layout.addWidget(self.button_stop)

        self.setLayout(layout)

        self.engine = pyttsx3.init()

        self.button_start.clicked.connect(self.start_timer)
        self.button_pause.clicked.connect(self.pause_timer)
        self.button_reset.clicked.connect(self.reset_timer)
        self.button_stop.clicked.connect(self.stop_timer)

    def start_timer(self):
        if self.timer_running:
            return

        try:
            self.countdown_sec = int(self.entry_time.text())
            if self.countdown_sec <= 0:
                raise ValueError
        except ValueError:
            self.show_error_message("请输入一个正整数的倒计时时间")
            return

        self.remaining_sec = self.countdown_sec
        self.update_time_label()

        self.button_start.setEnabled(False)
        self.button_pause.setEnabled(True)
        self.button_reset.setEnabled(True)
        self.button_stop.setEnabled(True)

        self.timer_running = True
        self.timer_tick()

    def pause_timer(self):
        if not self.timer_running:
            return

        self.timer_running = False
        self.button_pause.setText("继续")

    def reset_timer(self):
        self.timer_running = False
        self.remaining_sec = self.countdown_sec
        self.update_time_label()

        self.button_start.setEnabled(True)
        self.button_pause.setEnabled(False)
        self.button_reset.setEnabled(False)
        self.button_stop.setEnabled(False)

    def stop_timer(self):
        self.timer_running = False
        self.remaining_sec = 0
        self.update_time_label()

        self.button_start.setEnabled(True)
        self.button_pause.setEnabled(False)
        self.button_reset.setEnabled(False)
        self.button_stop.setEnabled(False)

    def timer_tick(self):
        if self.remaining_sec <= 0:
            self.timer_running = False
            self.update_time_label()
            self.play_audio()
            return

        self.update_time_label()
        self.remaining_sec -= 1

        if self.timer_running:
            QTimer.singleShot(1000, self.timer_tick)

    def update_time_label(self):
        hours = self.remaining_sec // 3600
        minutes = (self.remaining_sec % 3600) // 60
        seconds = self.remaining_sec % 60

        time_str = "{:02d}:{:02d}:{:02d}".format(hours, minutes, seconds)
        self.label_time.setText(time_str)

    def play_audio(self):
        self.engine.say("倒计时结束")
        self.engine.runAndWait()

    def show_error_message(self, message):
        QMessageBox.critical(self, "错误", message)

if __name__ == "__main__":
    app = QApplication(sys.argv)
    timer = CountdownTimer()
    timer.show()
    sys.exit(app.exec_())

运行以上代码，将会弹出一个使用PyQt5实现的悬浮窗口倒计时工具。你可以在输入框中输入倒计时时间（秒），然后点击开始按钮即可开始倒计时。在倒计时结束时，会有语音提醒。

请注意，你需要先安装PyQt5库和pyttsx3库，可以使用以下命令安装：

pip install PyQt5 pyttsx3

希望以上代码能够满足你的需求！如有其他问题，请随时提问。