preを任意の横幅で改行させましょう

↓これを入れるだけ。

	white-space: pre;           /* CSS 2.0 */
	white-space: pre-wrap;      /* CSS 2.1 */
	white-space: pre-line;      /* CSS 3.0 */
	white-space: -pre-wrap;     /* Opera 4-6 */
	white-space: -o-pre-wrap;   /* Opera 7 */
	white-space: -moz-pre-wrap; /* Mozilla */
	white-space: -hp-pre-wrap;  /* HP Printers */
	word-wrap: break-word;      /* IE 5+ */

CSS記述例

#aaaaaa pre{
	width:650px;
	word-break: break-all;
	white-space: pre;           /* CSS 2.0 */
	white-space: pre-wrap;      /* CSS 2.1 */
	white-space: pre-line;      /* CSS 3.0 */
	white-space: -pre-wrap;     /* Opera 4-6 */
	white-space: -o-pre-wrap;   /* Opera 7 */
	white-space: -moz-pre-wrap; /* Mozilla */
	white-space: -hp-pre-wrap;  /* HP Printers */
	word-wrap: break-word;      /* IE 5+ */
	}