WAAA THANKYUUU!!!!!

You can use the @media css rule to change properties depending on screen-size. E.g. @media(max-width: 1290px){ colour: red; } would make the text colour of the page red if the page is less than 1290px in width, which is the amount I use for changing the layout for phones on my site. I can't inspect your code rn Im not sure if thisll be any help but maybe a flexbox could help also

just inspect your index, if you were using that column-wrapper I suggested, you should use it only at the top level, all the other divs (left, center, right) inside of it (not each inside a new column-wrapper), flex and width values are conflicting there, it seems like you want center 60% and the other two 20%, so on center-column you can just write flex: 3 (flexbox count becomes 1x+3x+1x = 100%, x=20%)

if view stills weird on mobile after that, then use media css rules like @irrelevantreviews said, you add his example to style and then inside of it you add a new header, like @media(max-width:XXXXpx){ header {your property changes here} } (that XXXX is because it's different values for phones and tablets, usually 768px for phones and 1024px or 1200px for tablets), fixing one might not fix the other, so you may need

a different set of rules for each)

argh, my english, first message was supposed to be "I just inspected your index, if you are using that"

to @irrelecantreviews: "colour" man get yo british ass outta here

I set my mobile layouts based on portrait vs. landscape orientation -- that probably isn't the best way to do it, but I know there are some heckin wide phones these days and generally speaking, a vertical window is probably a phone.