#main{
 float : left;
 width: 100%;
 margin-right : -400px;
}

#main_contents{
 margin:5px 400px 5px 10px;
}

/* サイドメニュー */
#sidebar{
 float : right;
 width: 355px;
 margin:5px 10px 20px 10px;
 padding-left:10px;
 padding-bottom:50px;
 border-left:dotted 5px #bb9911;
}

#sidebar_contents{
 width:200px;
 float:left;
 margin-left:10px;
 padding-left:10px;
 border-left:dotted 5px #bb9911;
}

#sample_problems_sidebar{
 width:130px;
 float:left;
}

#sample_problems_sidebar img{
 float:left;
 margin:0px 5px 5px 0px;
}

#sample_problems_sidebar h3{
 border:none;
 padding:0px;
 font-size:1em;
}

#sample_problems_sidebar h3 a{
 border:none;
 display: block;
 width: 100%;
}

#sample_problems_sidebar h3 a:hover{
 background-color:#ffff00;
 border:none;
}

#sample_problems_sidebar p{
 font-size:0.9em;
}

h2{
 font-size:1.1em;
}

h3{
 font-size:1em;
}