* {
    margin: 0;
    padding: 0
}

body, html {
    height: 100%;
    min-width: 1200px;
    font-family: PingFangSC-Regular, sans-serif;
    cursor: default
}

a, a:link, a:visited {
    text-decoration: none
}

em, i {
    font-style: normal
}

li {
    list-style: none
}

img {
    border: none;
    max-width: 100%
}

.section_lesson li {
    margin-bottom: 30px;
    color: #333;
}

.sectionC img,
.section_lesson img {
    max-width: 90%;
}

.sectionB p {
    padding: 10px 0 ;
    text-align: center;
    color: #333;
}

.sectionB img {
    height: 280px;
}