*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
.main_container{
  width: 100%;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}
#login{
  /* border: 1px solid; */
  width: 100%;
  max-width: 500px;
  margin: 0 auto;
}
.form{
  /* border: 1px solid; */
  padding: .6rem;
}
#username, #password{
  width: 100%;
  padding: .6rem;
  margin-top: .8rem;
  border-radius: .6rem;
}

input[type=submit] {
  width: 100%;
 background-color: green;
 color:white;
 margin-top: .8rem;
 padding: .6rem;
 border-radius: .6rem;
    
}


 .invalid { 
color:red; 
font-family: arial; 
text-align: center;
margin-top: 1rem;

}