xiaoben-as2-php/css/teaching/physics/topic.css

* {
    margin: 0;
    padding: 0;
}

.clearfix::after {
    content: '.';
    height: 0;
    display: block;
    visibility: hidden;
    clear: both;
}

.topic-common {
    font-size: 7.5pt;
    font-family: 'SimSun';
}

.topic-common img {
    vertical-align: middle;
}

.topic-stem-202109 {
    line-height: 1.5em;
    text-align: justify;
    margin-bottom: 1em;
}

.option-ul-202109 {
    list-style: none;
    margin-bottom: 1em;
    page-break-inside: avoid !important;
}

.option-li-202109 {
    position: relative;
    line-height: 1.5em;
    display: -webkit-flex;
    display: flex;
    -webkit-align-items: baseline;
    align-items: baseline;
}

.option-li-202109 .option-label-202109 {
    /* position: absolute; */
    /* top: 0; */
    /* left: 0; */
}

.option-li-202109 .option-content-202109 {
    /* margin-left: 1em; */
    min-height: 1.5em;
    text-align: justify;
}

.answer-202109 {
    display: -webkit-flex;
    display: flex;
    margin-bottom: 0.5em;
    page-break-inside: avoid !important;
}

.answer-202109 .long-empty {
    /* display: -webkit-flex;
    display: flex; */
    page-break-inside: avoid !important;
}

.answer-202109 .answer-label-202109 {
    margin-left: -0.4em;
}

.analysis-202109 {
    position: relative;
    min-height: 1em;
    margin-bottom: 0.5em;
}

.analysis-202109 .analysis-label-202109 {
    position: absolute;
    left: -0.4em;
}

.analysis-202109 .analysis-content-202109 {
    text-align: justify;
    text-indent: 3.5em;
    line-height: 1.5em;
}

.y-4 li {
    margin-bottom: 0.5em;
}

.y-4 li:last-child {
    margin-bottom: 0;
}

.xy-2 {
    display: -webkit-flex;
    display: flex;
    -webkit-flex-wrap: wrap;
    flex-wrap: wrap;
    -webkit-justify-content: space-between;
    justify-content: space-between;
}

.xy-2 li {
    width: 50%;
    margin-bottom: 0.5em;
    box-sizing: border-box;
}

.xy-2 li:nth-child(odd) {
    padding-right: 1em;
}

.xy-2 li:nth-child(n+3) {
    margin-bottom: 0;
}

.x-4 {
    display: -webkit-flex;
    display: flex;
    -webkit-justify-content: space-between;
    justify-content: space-between;
}

.x-4 li {
    width: 25%;
}

.x-4 li:nth-child(-n+3) {
    padding-right: 1em;
}