body{
     background-color: #000;
}
.header-up {
         list-style: none;
         background-color: #000;
    background-size: cover;
     background-position: center top;
    text-align: left; 
    color:#FFFFFF;
    font-size: 26px;
}

.button {
  background-color: #4CAF50; /* Green */
  border: none;
  color: white;
  padding: 10px 20px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 24px;
  margin: 4px 2px;
  cursor: pointer;
     background-color: #000;
  color: white;
}