.ribbon_box {    
    display: block;
    position: relative;
    margin: 15px auto;
    padding: 10px 0;
    width: 300px;
    background: #f1f1f1;
  }

.ribbon10 {
    display: inline-block;
    position: relative;
    box-sizing: border-box;
    padding: 5px 0;
    margin: 0 0 0 -20px;
    width: calc(100% + 20px);
    color: white;
    background: #660099;
    box-shadow: 0 2px 2px rgba(0, 0, 0, 0.2);
}

.ribbon10 h3{
    vertical-align: middle;
    margin: 0;
    padding: 0 30px 0 15px;
    border-top: dashed 1px #FFF;
    border-bottom: dashed 1px #FFF;
    font-size: 20px;
    line-height: 46px;
}

.ribbon10:after{
    position: absolute;
    content: '';
    z-index: 1;
    top: 0;
    right: 0;
    width: 0px;
    height: 0px;
    border-width: 30px 15px 30px 0px;
    border-color: transparent #f1f1f1 transparent transparent;
    border-style: solid;
}

.ribbon10:before {
    position: absolute;
    content: '';
    top: 100%;
    left: 0;
    border: none;
    border-bottom: solid 15px transparent;
    border-right: solid 20px #331F33;
}


.under {
  border-bottom: dotted 2px #660099;
  }


body {
font-family: 'Avenir','Helvetica Neue','Helvetica','Arial','Hiragino Sans','ヒラギノ角ゴシック',YuGothic,'Yu Gothic','メイリオ', Meiryo,'ＭＳ Ｐゴシック','MS PGothic'  
}