float.css

.wrapper {
    display: flex;
    margin: 50px auto;
    width: auto;
    overflow: hidden;
    border-radius: 8px;
    padding: 15px;
    box-shadow: 20px 20px 60px #bebebe, -20px -20px 60px #ffffff;
}

.text {
    width: 88%;
    font-size: 0.8rem;
    overflow: hidden;
    padding: 20px;
    padding-top: 10px;
    padding-bottom: 10px;
    padding-right: 15px;
    text-overflow: ellipsis;
    text-align: justify;
    background: #f1f1f1;
    margin: auto;
    line-height: 1.3rem;
    border-radius: 10px;
    /* display: flex; */
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    position: relative;
}

.text::before {
    content: '';
    height: calc(100% - 24px);
    float: right;
    background: #000
}

.text::after {
    content: '';
    width: 100%;
    height: 100%;
    position: absolute;
    background: #fff;
}

.btn {
    float: right;
    clear: both;
    margin-left: 10px;
    font-size: 0.8rem;
    padding: 0 8px;
    background: #3c6e9e;
    line-height: 24px;
    border-radius: 4px;
    color: #fff;
    cursor: pointer;
    /* margin-top: -30px; */
}

.btn::before {
    content: '展开'
}

.exp {
    display: none;
}

.exp:checked+.text {
    -webkit-line-clamp: 999;
}

.exp:checked+.text .btn::before {
    content: '收起'
}