How to change the header style of a SharePoint site

[@AyazAfandiyev-no3oz]

Those buttons Edit and Republish from right corner jave dissapeared on my site after i worked for quite long, now i can not see them. What could be reason?

[@pipeoxide]

merci, brate!

[@thaqsheelv1387]

How can I add 2 headers?

[@TheBareSaint]

all ist good until i turn on the sound.