*{font-family: calibri;}
#instelknop1 {background-color: gold; color: black; border: 0px;}
#instelknop2 {background-color: gold; color: black; border: 0px; margin-left: -5px;}
#instelknop3 {background-color: gold; color: black; border: 0px; margin-left: -5px;}
#instelknop4 {background-color: gold; color: black; border: 0px; margin-left: -5px;}
#instelknop5 {background-color: gold; color: black; border: 0px; margin-left: -5px;}
#instelknop6 {background-color: gold; color: black; border: 0px; margin-left: -5px;}
@media screen and (min-width: 1155px){
  #menu {width: 1148px; height: 50px; margin: -15px auto 0px auto;}
  #instelknop1 {width: 190px; height: 50px; font-size: 25px;  margin-left: 7px; backgroun-color: red;}
  #instelknop2 {width: 200px; height: 50px; font-size: 25px;}
  #instelknop3 {width: 180px; height: 50px; font-size: 25px;}
  #instelknop4 {width: 180px; height: 50px; font-size: 25px;}
  #instelknop5 {width: 200px; height: 50px; font-size: 25px;}
  #instelknop6 {width: 190px; height: 50px; font-size: 25px;}
}
@media screen and (min-width: 770px) and (max-width: 1155px){
  #menu {width: 760px; margin: -15px auto 0px auto;}
  #instelknop1 {width: 129px; height: 50px; font-size: 20px;}
  #instelknop2 {width: 129px; height: 50px; font-size: 20px;}
  #instelknop3 {width: 107px; height: 50px; font-size: 20px;}
  #instelknop4 {width: 107px; height: 50px; font-size: 20px;}
  #instelknop5 {width: 171px; height: 50px; font-size: 20px;}
  #instelknop6 {width: 107px; height: 50px; font-size: 20px;}
}
@media screen and (min-width: 690px) and (max-width: 770px){
  #menu {width: 680px; margin: -15px auto 0px auto;}
  #instelknop1 {width: 115px; height: 40px; font-size: 17px;}
  #instelknop2 {width: 115px; height: 40px; font-size: 17px;}
  #instelknop3 {width: 96px; height: 40px; font-size: 17px;}
  #instelknop4 {width: 96px; height: 40px; font-size: 17px;}
  #instelknop5 {width: 154px; height: 40px; font-size: 17px;}
  #instelknop6 {width: 96px; height: 40px; font-size: 17px;}
}
@media screen and (min-width: 395px) and (max-width: 690px){
  #menu {width: 386px; margin: -15px auto 0px auto;}
  #instelknop1 {width: 58px; height: 40px; font-size: 18px; margin-left: 3px;}
  #instelknop2 {width: 70px; height: 40px; font-size: 18px;}
  #instelknop3 {width: 60px; height: 40px; font-size: 18px;}
  #instelknop4 {width: 54px; height: 40px; font-size: 18px;}
  #instelknop5 {width: 84px; height: 40px; font-size: 18px;}
  #instelknop6 {width: 52px; height: 40px; font-size: 18px;}
}
@media screen and (max-width: 395px){
  #menu {width: 356px; margin: -15px auto 0px auto;}
  #instelknop1 {width: 123px; height: 40px; font-size: 18px;}
  #instelknop2 {width: 123px; height: 40px; font-size: 18px;}
  #instelknop3 {width: 105px; height: 40px; font-size: 18px;}
  #instelknop4 {width: 98px; height: 40px; font-size: 18px; margin-left: 0px;}
  #instelknop5 {width: 155px; height: 40px; font-size: 18px;}
  #instelknop6 {width: 98px; height: 40px; font-size: 18px;}
}