import tkinter as tk
from time import time

class TimerApp:
    def __init__(self, root):
        self.root = root
        self.root.title("简易定时器")
        self.root.geometry("450x300")

        self.running = False
        self.start_time = 0
        self.elapsed = 0

        # 显示时间标签
        self.label = tk.Label(root, text="0.00", font=("Arial", 60))
        self.label.pack(pady=30)

        # 按钮容器
        frame = tk.Frame(root)
        frame.pack()
        tk.Button(frame, text="开始", command=self.start, width=8, height=2, bg="#4cd964").grid(row=0, column=0, padx=5)
        tk.Button(frame, text="暂停", command=self.pause, width=8, height=2, bg="#ff9500").grid(row=0, column=1, padx=5)
        tk.Button(frame, text="重置", command=self.reset, width=8, height=2, bg="#ff3b30").grid(row=0, column=2, padx=5)
        self.update_clock()

    def start(self):
        if not self.running:
            self.start_time = time() - self.elapsed
            self.running = True

    def pause(self):
        if self.running:
            self.elapsed = time() - self.start_time
            self.running = False

    def reset(self):
        self.running = False
        self.elapsed = 0
        self.label.config(text="0.00")

    def update_clock(self):
        if self.running:
            self.elapsed = time() - self.start_time
        self.label.config(text=f"{self.elapsed:.2f}")
        self.root.after(20, self.update_clock)

if __name__ == "__main__":
    win = tk.Tk()
    app = TimerApp(win)
    win.mainloop()