doc.silverstripe.org/themes/tutorial/css/form.css

/* GENERIC FORM STYLING */
#Content form {
	width:378px;
}
	#Content form fieldset {
		border:0;
		padding:12px;
	}
		#Content .message {
			color:red;
			background:#ddd;
			border:1px solid #ccc;
			padding:5px;
			margin:5px;
		}
		#Content span.message {
			width: 300px;
		}
		#Content form div {
			margin-top:10px;
			width:100%;
		}
		#Content form label {
			font-size:1.1em;
			color:#333;
		}
			#Content form label.left {
				float:left;
				width:12em;
			}
			#Content form label.FormHeading {
				font-size:1.3em;
				color:#ff7200;
				font-weight:bold;
			}
		#Content form input.text,
		#Content form textarea,
		#Content form select {
			width:200px;
			color:#000;
			background:#f8f8f8;
			border:1px solid #aaa;
			padding:3px;
		}
		
		#Content form input.numeric {
			width:20px;
			background:#f0f0f0;
			border:1px solid #aaa;
			padding:3px;
			color:#000;
			margin-right:4px;
		}
		#Content form input.year {
			width:35px;
		}
		#Content form p.Actions {
			text-align:right;
			padding:0 22px 15px 0;
		}
			#Content form p.Actions input {
				padding:2px;
			}