.accordion-box {
    position: relative;
}

.accordion-box label {
    height: 140px;
    /* グラデーションの高さ */
    cursor: pointer;
    text-align: center;
    font-size: 14px;
    position: absolute;
    bottom: 0;
    width: 100%;
    /* 以下グラデーションは「背景がグレー」に併せて設定 */
    background: -webkit-linear-gradient(top, rgba(248, 248, 248, 0) 0%, rgba(248, 248, 248, 0.85) 95%);
    background: -moz-linear-gradient(top, rgba(248, 248, 248, 0) 0%, rgba(248, 248, 248, 0.85) 95%);
    background: -o-linear-gradient(top, rgba(248, 248, 248, 0) 0%, rgba(248, 248, 248, 0.85) 95%);
    background: -ms-linear-gradient(top, rgba(248, 248, 248, 0) 0%, rgba(248, 248, 248, 0.85) 95%);
    background: linear-gradient(to bottom, rgba(248, 248, 248, 0) 0%, rgba(248, 248, 248, 0.85) 95%);
}

.accordion-box input:checked+label {
    background: inherit;
    /* 開いた時には背景グラデーションを消す */
}

.accordion-box label:after {
    content: "続きを読む";
    /* ラベルの文字 */
    letter-spacing: .05em;
    line-height: 2.5rem;
    position: absolute;
    bottom: 0px;
    left: 50%;
    -webkit-transform: translate(-50%, 0);
    transform: translate(-50%, 0);
    color: #000000;
    background-color: #e1e1e1;
    width: 18.75rem;
    -webkit-border-radius: 20px;
    -moz-border-radius: 20px;
    border-radius: 20px;
}

.accordion-box label:before {
    content: "↓";
    font-weight: 700;
    position: absolute;
    bottom: 10px;
    left: 50%;
    -webkit-transform: translate(-10px, 0);
    transform: translate(-140px, 0);
    background-color: #fff;
    z-index: 1;
    -webkit-border-radius: 100%;
    -moz-border-radius: 100%;
    border-radius: 100%;
    width: 20px;
    height: 20px;
    line-height: 20px;
}

.accordion-box input {
    display: none;
}

.accordion-box .accordion-container {
    overflow: hidden;
    height: 100px;
    /* 開く前に見えている部分の高さ */
    -webkit-transition: all 0.1s;
    -moz-transition: all 0.1s;
    -ms-transition: all 0.1s;
    -o-transition: all 0.1s;
    transition: all 0.1s;
}

.accordion-box input:checked+label {
    /* display: none ; 閉じるボタンは要らないとき */
    display: none;
}

/* 閉じるボタンをやめる　2018/4/24
.accordion-box input:checked + label:after {
    content: "閉じる";
}
.accordion-box input:checked + label:before {
    content: "↑";
}
*/

.accordion-box input:checked~.accordion-container {
    height: auto;
    padding-bottom: 20px;
    /* 閉じるボタンのbottomからの位置 */
    -webkit-transition: all 0.1s;
    -moz-transition: all 0.1s;
    -ms-transition: all 0.1s;
    -o-transition: all 0.1s;
    transition: all 0.1s;
}