style.css

body{
    margin: auto;
    width: 100%;
    padding: 0;
    box-sizing: border-box;
    text-align: center;
 }
 label {
     display: inline-block;
     width: 100px;
     font-weight: bold;
     margin-bottom: 10px;
   }
   
 input ,textarea{
     width: 200px;
     margin-bottom: 10px;
     padding: 5px;
     border-radius: 3px;
 }
   
 button[type="submit"] {
     padding: 10px 20px;
     font-size: 16px;
     border-radius: 3px;
     cursor: pointer
 }
 table {
    border-collapse: collapse;
    border: 1px solid #ccc;
    margin-left:auto; 
    margin-right:auto;
}
  
td, th {
    border: 1px solid #ccc;
    padding: 5px;
} 

#marks {
    display: inline-block;
    vertical-align: top;
    margin-top: 10px;
    margin-right: 10px;
}
textarea {
    display: inline-block;
    vertical-align: top;
    margin-top: 10px;
}

#country-code{
    padding:5px;
}