select, textarea, input[type="text"], input[type="password"], input[type="datetime"], input[type="datetime-local"], input[type="date"], input[type="month"], input[type="time"], input[type="week"], input[type="number"], input[type="email"], input[type="url"], input[type="search"], input[type="tel"], input[type="color"], .uneditable-input {
display: block;
padding: 6px 12px;
font-size: 14px;
line-height: 1.428571429;
color: #555555;
background-color: #fff;
background-image: none;
border: 1px solid #ccc;
border-radius: 4px;
-webkit-box-shadow: inset 0 1px 1px rgba(0,0,0,0.075);
box-shadow: inset 0 1px 1px rgba(0,0,0,0.075);
-webkit-transition: border-color ease-in-out .15s, box-shadow ease-in-out .15s;
-o-transition: border-color ease-in-out .15s, box-shadow ease-in-out .15s;
transition: border-color ease-in-out .15s, box-shadow ease-in-out .15s;
}
from the file /templates/elegance/css/template.css of your template and that should display the quantity field properly.