拉伸循環計時器

極簡易的循環計時器，主要是用來給久坐的上班族在辦公室座位上做拉伸活動時做提醒，每組計時完成後會有聲音提醒，反覆繼續。可在背景執行，不影響螢幕前工作。 This extremely simple loop timer is primarily designed to remind office workers who sit for long periods to perform stretching exercises while seated. It provides an audible alert after each set of timers completes and repeats continuously. It can run in the background without interfering with work on the screen. 1.3 更新：修正計時器在新版 Chrome 下每秒倒數不正確的問題