text: window.onscroll=function(){
      rolagem()
  };
  
  function rolagem(){
      if(document.body.scrollTop > 50 || document.documentElement.scrollTOp > 50){
          document.getElementsByTagName("header")[0].style.padding="30px 10px";
          document.getElementById("logo").style.fontSize="25px";
      }else{
          document.getElementsByTagName("header")[0].style.padding="80px 10px";
          document.getElementById("logo").style.fontSize="35px";
      }
  }