/* 清除通配符样式 */
* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

/* 清除超链接a的默认样式 */
a {
    text-decoration: none;
}

/* 网页主体背景颜色 */
body {
    background-color: #f7f8fa;
    /* Helvetica设计师最爱,  Arial是前一个的克隆, 英文网站一律是Verdana*/
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', Helvetica, Arial, Verdana, Geneva, Tahoma, sans-serif, 'Times New Roman', Times, serif;
}

/* 清除ul的样式 */
ul {
    list-style: none;
}

/* 媒体查询 屏幕像素大于992px */
@media screen and (min-width: 992px) and (max-width: 1199px) {
    
    /* 顶部导航栏 */
    .header {
        position: fixed;
        top: 0px;
        left: 0px;
        width: 100%;
        height: 48px;
        line-height: 48px;
        text-align: center;
        background-color: #e7e8e9;
        color: #343a40;
        /*box-shadow: 0 1px 1px #343a40;*/
    }
    .header .headbar {
        position: relative;
        width: 970px;
        margin: 0 auto;
    }
    .headbar h1 {
        font-size: 20px;
        font-weight: 400;
    }
    
    /* 主要显示区域 */
    .mainarea {
        display: flex;
        flex-direction: column;
        justify-content: space-between;
        align-items: center;
        position: absolute;
        top: 50px;
        left: 50%;
        transform: translateX(-50%);
        bottom: 50px;
        min-width: 992px;
        padding: 0 24px;
    }
    .mainarea .download_area {
        flex: 1;
        display: flex;
        flex-direction: column;
        justify-content: space-between;
        width: 100%;
    }
    .mainarea .download_area li:first-child {
        flex: 1;
        display: flex;
        flex-direction: row;
        justify-content: flex-start;
        align-items: center;
    }
    .mainarea .download_area li:first-child h3 {
        font-weight: 400;
        color: #666666;
    }
    .mainarea .download_area li:nth-child(2) {
        flex: 1;
        display: flex;
        flex-direction: row;
        justify-content: flex-start;
        align-items: center;
        font-size: 18px;
    }
    .mainarea .download_area li:nth-child(2) span {
        border: 1px solid #e7e8e9;
        display: flex;
        flex-direction: row;
        justify-content: center;
        align-items: center;
        height: 100%;
    }
    .mainarea .download_area li:nth-child(2) span:first-child {

        width: 120px;
    }
    .mainarea .download_area li:last-child {
        flex: 1;
        display: flex;
        flex-direction: row;
        justify-content: flex-end;
        align-items: center;
    }
    .mainarea .download_area li:last-child a {
        width: 120px;
        height: 100%;
    }
    .mainarea .download_area li:last-child a button {
        display: block;
        width: 100%;
        height: 100%;
        font-size: 18px;
        color: #343a40;
        outline: none;
        border: none;
        background-color: #e7e8e9;
    }
    
    /* 底部导航栏 */
    footer {
        position: fixed;
        left: 0px;
        bottom: 0px;
        overflow: hidden;

        width: 100%;
        background-color: #e7e8e9;
        color: #343a40;
        text-align: center;
    }

    footer p {
        margin: 6px auto;
        font-size: 12px;
    }

    footer a {
        color: #343a40;
    }

}

/* 媒体查询 屏幕像素大于1200px */
@media screen and (min-width: 1200px) {

    /* 顶部主题栏 */
    .header {
        position: fixed;
        top: 0px;
        left: 0px;
        width: 100%;
        background-color: #e7e8e9;
        color: #343a40;
        /*box-shadow: 0 1px 1px #343a40;*/
        /* z-index: 999; */
        height: 48px;
        line-height: 48px;
        text-align: center;
    }
    .header .headbar {
        position: relative;
        width: 1190px;
        margin: 0 auto;
    }
    .headbar h1 {
        font-weight: 400;
        font-size: 20px;
    }
    
    /* 主要显示区域 */
    .mainarea {
        display: flex;
        flex-direction: column;
        justify-content: space-between;
        align-items: center;
        position: absolute;
        top: 50px;
        left: 50%;
        transform: translateX(-50%);
        bottom: 50px;
        width: 1190px;
    }
    .mainarea .download_area {
        flex: 1;
        display: flex;
        flex-direction: column;
        justify-content: space-between;
        width: 100%;
    }
    .mainarea .download_area li:first-child {
        flex: 1;
        display: flex;
        flex-direction: row;
        justify-content: flex-start;
        align-items: center;
    }
    .mainarea .download_area li:first-child h3 {
        font-weight: 400;
        color: #666666;
    }
    .mainarea .download_area li:nth-child(2) {
        flex: 1;
        display: flex;
        flex-direction: row;
        justify-content: flex-start;
        align-items: center;
        font-size: 18px;
    }
    .mainarea .download_area li:nth-child(2) span {
        border: 1px solid #e7e8e9;
        display: flex;
        flex-direction: row;
        justify-content: center;
        align-items: center;
        height: 100%;
    }
    .mainarea .download_area li:nth-child(2) span:first-child {

        width: 120px;
    }
    .mainarea .download_area li:last-child {
        flex: 1;
        display: flex;
        flex-direction: row;
        justify-content: flex-end;
        align-items: center;
    }
    .mainarea .download_area li:last-child a {
        width: 120px;
        height: 100%;
    }
    .mainarea .download_area li:last-child a button {
        display: block;
        width: 100%;
        height: 100%;
        font-size: 18px;
        color: #343a40;
        outline: none;
        border: none;
        background-color: #e7e8e9;
    }
    
    /* 底部导航栏 */
    footer {
        position: fixed;
        left: 0;
        bottom: 0;
        overflow: hidden;
        width: 100%;
        background-color: #e7e8e9;
        color: #343a40;
        text-align: center;
    }

    footer p {
        margin: 6px auto;
        font-size: 12px;
    }

    footer a {
        color: #343a40;
    }

}