.hg_block__same-event-posts--style1 {
    display: block;
    margin: 1em 0;
    padding: 1em;
    background-color: #fff;
    border-radius: 10px;
}
.hg_block__same-event-posts--style1 > div {
    margin: 0;
    padding: 0;
    text-align: center;
    font-weight: bold;
    color: #333;
}
.hg_block__same-event-posts--style1 ul {
    margin: 0;
    padding-left: 1em;
    font-size: 0.9em;
}
.hg_block__same-event-posts--style1 ul li {
    margin: 0.5em 0;
    padding: 0;
    color: #666;
}
.hg_block__same-event-posts--style1 ul li a{
    color: #333;
}
.hg_block__same-event-posts--style1 summary {
    content: "全て表示";
    box-sizing: border-box;
    width: 40%;
    margin: 1em auto;
    padding: 0.5em;
    white-space: nowrap;
    text-align: center;
    background-color: #f0f0f0;
    border-radius: 10px;
    cursor: pointer;
    list-style: none;
}
.hg_block__same-event-posts--style1 summary:after {
    content: "全て表示";
}
.hg_block__same-event-posts--style1 details[open] summary:after {
    content: "閉じる";
}
.hg_block__same-event-posts--style1 summary > span {
    display: inline-block;
    height: calc(tan(60deg) * 1em / 2);
    width: 1em;
    margin: 3px;
    clip-path: polygon(50% 0, 100% 100%, 0 100%);
    transform: rotate( 0deg );
    transition: all 200ms linear;
    background-color: #000;
    vertical-align: text-bottom;
}
.hg_block__same-event-posts--style1 details[open] summary > span {
    transform: rotate( 180deg );    
}

.hg_block__same-event-posts--editor {
    display: block;
    margin: 1em 0;
    padding: 2em;
    border: 2px solid #ccc;
    text-align: center;
    border-radius: 5px;
    background-color: #f0f0f0;
}