body {
    font-family:'Noto Sans JP',sans-serif;
    background-color:#f12afff;
}
p1{
    padding: 10px;
    margin-bottom: 10px;
    border: 1px dotted #333333;
    background-color: #506396;
    color: #ffffff;
}
.side_bar {
    background-color:#ffffff;
    width:320px;
    height:640px;
    text-align:left;
    margin-left:10px
}
.content_bar {
    background-color:#ffffff;
    width:840px;
    height:840px;
    text-align:left;
    overflow: scroll;
    margin-left:10px;
}
article {
    display:flex;
}
.timeline {
    list-style: none;
}
.timeline > li {
    margin-bottom: 60px;
}

/* for Desktop */
@media ( min-width : 640px ){
    .timeline > li {
        overflow: hidden;
        margin: 0;
        position: relative;
    }
    .timeline-date {
        width: 110px;
        float: left;
        margin-top: 20px;
    }
    .timeline-content {
        width: 90%;
        float: left;
        border-left: 4px #e5e5d1 solid;
        padding-left: 20px;
    }
    .timeline-content:before {
        content: "■";
        width: 10px;
        height: 15px;
        position: absolute;
        left: 5px;
        top: 60px;
        border-radius: 120%;
    }
}