soal 1 - benerin css

<style>
#container {
    background-color:#FFF;
    min-height:100px;
    border-bottom-right-radius:10px;
    border-bottom-left-radius:10px;
    border-top-right-radius:10px;
    border-top-left-radius:10px;
    -moz-box-shadow: 0 0 5px #333;
    -webkit-box-shadow: 0 0 5px #333;
    box-shadow: 0 0 5px  #333;
}

.kiri{
    float:left;
    width:400px;
    margin:10px;
}
.kanan{
    float:right;
    width:400px;
    margin:10px;
}
</style>
<div id='container' style='margin:auto; width:940px;'>

    <div class='kiri'>
        Tulisan Kiri
    </div>
    <div class='kanan'>
        tulisan kanan
    </div>
</div>