After I've added <!DOCTYPE html>, everything became buggy

Title. Please, can someone help me on voicechat or codepen? I'd like to learn how to fix this problem and to fix my website. I'm working on this uni project and I'm making a website. I forgot to put the <!DOCTYPE html>, but after i've added it, everuthing became buggy, like, the background image it's too big or too little and repeats itself, the buttons are bugged, when I click one, everything on the screen moves down, I've tried to work on the dimensions of the css elements, but nothing changes
6 Replies
Jochem
Jochem5mo ago
you're much more likely to get help if you share your code and describe what you mean by "buggy". Asking people to voicechat is fine, but it's a much bigger time and effort commitment on the solver's part than just being able to look at code and type something out
Sappey
Sappey5mo ago
I see
Jochem
Jochem5mo ago
we've got #how-to-ask-good-questions to help you with what information people might need to solve your problem
Sappey
Sappey5mo ago
essentialy, I'm working on this uni project and I'm making a website. I forgot to put the <!DOCTYPE html>, but after i've added it, everuthing became buggy, like, the background image it's too big or too little and repeats itself, the buttons are bugged, when I click one, everything on the screen moves down, I've tried to work on the dimensions of the css elements, but nothing changes
Jochem
Jochem5mo ago
not putting the doctype in, probably makes the browser render your site in quirks mode where it pretends to be a much older browser and renders things weirdly. Honestly, your site was buggy before and you probably just worked around that, and now those workarounds are causing issues. There is nothing anyone can do to help you past that without seeing the code, preferably live on something like codepen or codesandbox though
Sappey
Sappey5mo ago
I can use codepen I've just registred to it so i can use it