.calendar_btn {
    width: 100%;
    margin: 10px 0 0 0;
    padding: 5px 0 5px 0;
    font-size: 16px;
    line-height: 1.5;
    display: inline-block;
    text-decoration: none;
    color: #eee;
    text-align: center;
    -webkit-border-radius: 3px;
    -moz-border-radius: 3px;
    border-radius: 3px;
    font-weight: bold;
    background: #e62;    
  }
  
@media screen and (max-width: 761px) {
    .calendar_btn {
        font-size: 12px;
    }
}

#calendar{
    width: 100%;
    max-width: 1200px;
}