* {
    margin: 0;
    padding: 0;
}

html {
    font-size: 10px;
}

#top, #main, #bottom {
    width: 100%;
}

#top {
    position: fixed;   /* 固定位置 */
    top: 0;
    left: 0;
    right: 0;
    height: 2rem;
    z-index: 1000;
    background-color: #f5f5f5;
}

#logo {
    width: 4rem;
    height: 1rem;
    vertical-align: -webkit-baseline-middle;    /* 垂直居中 */
}

#main {
    height: auto;   /* 高度设置为自动 */
    position: absolute;
    top: 2rem;
    border: 2rem;
    background-color: #f5f5f5;
}

#main ul {
    display: flex;
    /* 主轴方向为纵轴 */
    flex-direction: column;
    /* 两端对齐 */
    justify-content: space-between;
    font-size: 0.5rem;
}

.shopCar {
    width: 1rem;
    height: 1rem;
    vertical-align: -webkit-baseline-middle;
}

.logo {
    width: 3.6rem;
    height: 2rem;
    vertical-align: -webkit-baseline-middle;
}

#main ul li {
    flex: 1 1 3rem;
    display: flex;
    border-bottom: 1px solid black;
    align-items: center;
}

#main ul li div {
    margin-left: 0.2rem;
    margin-right: 0.5rem;
}

#bottom {
    position: fixed;   /* 固定位置 */
    bottom: 0;
    left: 0;
    right: 0;
    height: 2rem;
    z-index: 1000;
    background-color: #f5f5f5;
    display: flex;
}

#bottom div {
    flex: 1 1 auto;
    text-align: center;
}

#bottom div img {
    width: 1.5rem;
    width: 1.5rem;
    vertical-align: -webkit-baseline-middle;
}