https://github.com/eris-c/atcoder-submit-tab-disabler/raw/master/disable-submit-tab.user.js
- this script just disables the "Submit" tab, and forces you to submit via each task's page.
- I often posted codes to different tasks ( = WA).
- both https://atcoder.jp/ and https://beta.atcoder.jp/ supported.
- Firefox + Greasemonkey, or Google Chrome + Tampermonkey