これは、css3グラデーション(およびIE 6-9のフィルターフォールバック)を使用して簡単に行うことができます。
実例:
http://jsfiddle.net/kdQ4y/またはhttp://jsfiddle.net/kdQ4y/1/
http://www.colorzilla.com/gradient-editor/を使用して生成されたグラデーションのコード
html構造
<div class="wrap">
<div class="top"></div>
<div class="content">Content here</div>
<div class="bottom"></div>
</div>
css(すべてが必要なわけではありません)
.wrap{
margin:40px;
position:relative;
padding:10px;
}
.content{
height:100px;
overflow-y:scroll;
}
.top,.bottom {
height:40px;
width:100%;
position:absolute;
left:0;
z-index:10;
}
.top{
top:0;
background: -moz-linear-gradient(top, rgba(255,255,255,1) 0%, rgba(255,255,255,0) 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(255,255,255,1)), color-stop(100%,rgba(255,255,255,0))); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, rgba(255,255,255,1) 0%,rgba(255,255,255,0) 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, rgba(255,255,255,1) 0%,rgba(255,255,255,0) 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(top, rgba(255,255,255,1) 0%,rgba(255,255,255,0) 100%); /* IE10+ */
background: linear-gradient(to bottom, rgba(255,255,255,1) 0%,rgba(255,255,255,0) 100%); /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#ffffff', endColorstr='#00ffffff',GradientType=0 ); /* IE6-9 */
}
.bottom {
bottom:0;
background: -moz-linear-gradient(top, rgba(255,255,255,0) 0%, rgba(255,255,255,1) 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(255,255,255,0)), color-stop(100%,rgba(255,255,255,1))); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, rgba(255,255,255,0) 0%,rgba(255,255,255,1) 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, rgba(255,255,255,0) 0%,rgba(255,255,255,1) 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(top, rgba(255,255,255,0) 0%,rgba(255,255,255,1) 100%); /* IE10+ */
background: linear-gradient(to bottom, rgba(255,255,255,0) 0%,rgba(255,255,255,1) 100%); /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#00ffffff', endColorstr='#ffffff',GradientType=0 ); /* IE6-9 */
}