Proprietà min-width

Metodo 1

/* for all browsers that understand min-width */
.container {
     position: relative;
     width: 90%;
     min-width: 400px;
}
.holder {
     display: block;
     color: #000;
}

/* method 1 a bodge for IE5.5 and IE6 browsers */
* html .container {
     border-right: 400px solid #fff;
}
* html .holder {
     display: inline-block;
     position: relative;
     margin-right: -400px;
}

Metodo 2

/* for all browsers that understand min-width */
.container2 {
     position: relative;
     width: 90%;
     min-width: 400px;
}
.holder2 {
     display: block;
     color:#000;
}
 
/* method 2 a bodge for IE browsers IE5.01, IE5.5 and IE6 */
* html .container2 {
     border-right: 400px solid #fff;
}
* html .holder2 {
     float: left;
     position: relative;
     margin-right: -400px;
}