<p><a class="target-fix" name="aaa">這裡是aaa</a></p>
<p><a href="#aaa">點這裡跳到aaa</a></p>

//自訂ＣＳＳ 錨點位移
.target-fix {
position: relative;
top: -80px;
display: block;
height: 0;
overflow: hidden;
}