/*aのスタイルは記述順に依存する*/
a:link {
	text-decoration: none;
	color:           black;
}
a:visited {
	text-decoration: none;
	color:           gray;
}

a:hover   {
	text-decoration: underline;
	color:           red;
}
a:active{
	text-decoration: underline;
	color:           red;
}