丸括弧
鉤括弧
#marukakko { position: relative; width: 200px; line-height: 100px; -webkit-box-sizing: border-box; box-sizing: border-box; margin: 50px auto; text-align: center; } #marukakko:before, #marukakko:after { position: absolute; top: 0; content: ''; width: 40px; height: 100%; border-radius: 50%; -webkit-box-sizing: border-box; box-sizing: border-box; } #marukakko:before { left: 0; border-left: 2px solid #555; } #marukakko:after { right: 0; border-right: 2px solid #555; } #kagikakko { position: relative; width: 200px; line-height: 100px; text-align: center; -webkit-box-sizing: border-box; box-sizing: border-box; margin: 50px auto; } #kagikakko:before, #kagikakko:after { position: absolute; content: ''; width: 20px; height: 40px; -webkit-box-sizing: border-box; box-sizing: border-box; } #kagikakko:before { top: 0; left: 00; border-top: 1px solid #555; border-left: 1px solid #555; } #kagikakko:after { bottom: 0; right: 0; border-bottom: 1px solid #555; border-right: 1px solid #555; }