Woodmart Single page – header and footer are not full width

Hello everybody,

the header on my single page https://redrhinocarrental.de/platzrechner/ unfortunately does not extend over the whole screen and has a white space at the edges even though all settings are set to full width in the wordpress editor or full length in the woodmart header customizer. furthermore the footer has a yellow box in the background which was also not set and the footer is not full width and not quite at the bottom of the website. can you help me with this problem? I have already adopted and checked all settings with chatgpt but e.g. the header switches back to the boxed version in 3 seconds even with custom css which commands the full width of the header. i need help with this