我想在 CSS 文本按钮上有一个图像。如果我将字体大小增加到 26 像素，图像会正确显示。我想将字体大小保持在 20 像素但正确地适合图像。
a.button {
border: 1px solid #979797;
}
a.button.icon {
padding-left: 11px;
}
a.button.icon span{
padding-left: 48px;
background: url(../img/gmail2.png) no-repeat;
}
a.button.icon.chat span {
background-position: 0px -48;
}
a.button {
background-image: -moz-linear-gradient(top, #ffffff, #dbdbdb);
background-image: -webkit-gradient(linear,left top,left bottom,
color-stop(0, #ffffff),color-stop(1, #dbdbdb));
filter: progid:DXImageTransform.Microsoft.gradient
(startColorStr='#ffffff', EndColorStr='#dbdbdb');
-ms-filter: "progid:DXImageTransform.Microsoft.gradient
(startColorStr='#ffffff', EndColorStr='#dbdbdb')";
border: 1px solid #fff;
-moz-box-shadow: 0px 0px 4px rgba(0, 0, 0, 0.4);
-webkit-box-shadow: 0px 0px 4px rgba(0, 0, 0, 0.4);
box-shadow: 0px 0px 4px rgba(0, 0, 0, 0.4);
border-radius: 2px;
-webkit-border-radius: 2px;
-moz-border-radius: 2px;
padding: 5px 5px;
text-decoration: none;
text-shadow: #fff 0 1px 0;
float: left;
margin-right: 15px;
margin-bottom: 15px;
display: block;
color: #597390;
line-height: 38px;
font-size: 20px;
font-weight: bold;
}