body {
    width: 100%;
    max-width: 640px;
    min-width: 320px;
    margin: 0 auto;
    color: #666;
    font-size: 14px;
    line-height: 1.5;
    font-family: -apple-system, Helvetica, sans-serif;
}
.app {
    height: 45px;
    background-color: #333333;
}
.app ul {
    margin: 0;
    padding: 0;
}
.app ul li {
    float: left;
    height: 45px;
    line-height: 45px;
    text-align: center;
    list-style: none;
}
.app ul li a {
    width: 100%;
    height: 100%;
    color: #fff;
}
.app ul li:nth-child(1) {
    width: 8%;
}
.app ul li:nth-child(1) img {
    width: 10px;
}
.app ul li:nth-child(2) {
    width: 10%;
}
.app ul li:nth-child(2) img {
    width: 30px;
}
.app ul li:nth-child(3) {
    width: 57%;
}
.app ul li:nth-child(4) {
    width: 25%;
    background-color: #f63515;
}
.search {
    position: fixed;
    overflow: hidden;
    width: 100%;
    height: 44px;
    max-width: 640px;
    min-width: 320px;
    z-index: 1;
}
.search_menu {
    position: absolute;
    top: 0;
    left: 0;
    width: 40px;
    height: 44px;
}
.search_menu::before {
    display: block;
    content: '';
    width: 20px;
    height: 18px;
    margin: 14px 0 0 15px;
    background: url(../images/s-btn.png) no-repeat;
    background-size: 20px 18px;
}
.search_box {
    position: relative;
    height: 30px;
    margin: 0 50px;
    margin-top: 7px;
    background-color: #fff;
    border-radius: 15px;
}
.search_land {
    position: absolute;
    top: 0;
    right: 0;
    width: 40px;
    height: 44px;
    color: #fff;
    line-height: 44px;
}
.search_icon {
    position: absolute;
    top: 8px;
    left: 13px;
    width: 20px;
    height: 15px;
    background: url(../images/jd.png) no-repeat;
    background-size: 20px 15px;
}
.search_icon::after {
    position: absolute;
    content: '';
    top: 0;
    right: -8px;
    width: 1px;
    height: 15px;
    background-color: #ccc;
}
.search_sou {
    position: absolute;
    top: 8px;
    left: 50px;
    width: 18px;
    height: 15px;
    background: url(../images/jd-sprites.png) no-repeat -81px 0;
    background-size: 200px auto;
}
/* css动画实现轮播 */
.slide {
    position: relative;
    width: 100%;
    height: 187px;
    margin: 0 auto;
}
.slide img {
    position: absolute;
    opacity: 0;
    top: 0;
    left: 0;
    width: 100%;
    animation: ad 8s linear infinite;
    z-index: -999999;
}
@keyframes ad {
    0% {
        opacity: 1;
    }
    25% {
        opacity: 1;
    } 
    26% {
        opacity: 0;
    }
    100% {
        opacity: 0;
    }
}
.brand {
    overflow: hidden;
    margin-top: 8px;
    border-radius: 10px 10px 0 0;
}
.brand div {
    float: left;
    width: 33.33%;
}
.brand div img {
    width: 100%;
}
nav {
    padding-top: 5px;
}
nav a {
    float: left;
    width: 20%;
    text-align: center;
}
nav a img {
    width: 40px;
    margin: 10px 0;
}
nav a span {
    display: block;
}
.news {
    margin-top: 20px;
}
.news a {
    float: left;
    box-sizing: border-box;
}
.news a img {
    width: 100%;
}
.news a:nth-child(1) {
    width: 50%;
}
.news a:nth-child(n+2) {
    width: 25%;
    border-left: 1px solid #ccc;
}
/* 增加了新的内容 */
.goods {
    float: left;
    margin-top: 8px;
    max-width: 640px;
    min-width: 320px;
    background-color: #f7f7f7;
}
.list_left {
    float: left;
    overflow: hidden;
    width: 45%;
    height: 260px;
    margin: 12px 0 0 14px;
    border-radius: 10px;
    background-color: #fff;
}
.list_right {
    float: right;
    overflow: hidden;
    width: 45%;
    height: 260px;
    margin: 12px 0 0 14px;
    border-radius: 10px;
    background-color: #fff;
}
.list_left:last-child,
.list_right:last-child {
    margin-bottom: 75px;
}
.list_left img,
.list_right img {
    width: 180px;
    height: 170px;
}
.list_left p,
.list_right p {
    overflow: hidden;
    width: 100%;
    margin-top: 8px;
    padding-left: 8px;
    color: #434343;
    /* 溢出显示省略号 */
    display: -webkit-box;
    /* 弹性盒子元素垂直排列 */
    -webkit-box-orient: vertical;
    /* 控制要显示的行数 */
    -webkit-line-clamp: 2;
}
.list_left span,
.list_right span {
    display: block;
    margin-top: -10px;
    padding-left: 8px;
    color: #ff4142;
    font-size: 20px;
}
.navigation {
    position: fixed;
    bottom: 0;
    width: 100%;
    height: 54px;
    max-width: 640px;
    min-width: 320px;
    margin: 0 auto;
    z-index: 1;
    background-color: #fff;
    box-shadow: 0 0 10px 0 hsl(0deg 6% 58% / 60%);
}
.navigation a {
    float: left;
    display: block;
    width: 25%;
    height: 54px;
    text-align: center;
    line-height: 54px;
}
.navigation a img {
    width: 64px;
}