nav {
    font-family: Georgia, "Nimbus Roman No9 L", "Songti SC", STSong, "AR PL New Sung", "AR PL SungtiL GB", NSimSun, SimSun, "TW\-Sung", "WenQuanYi Bitmap Song", "AR PL UMing CN", "AR PL UMing HK", "AR PL UMing TW", "AR PL UMing TW MBE", PMingLiU, MingLiU, serif;
    /* 为菜单列的英文设置英文字体*/
    background-color: #ffe89c;
}

nav ul {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
}

nav ul li {
    flex-grow: 1;
    flex-shrink: 1;
    flex-basis: auto;
}

nav ul li a:link,
nav ul li a:hover,
nav ul li a:visited {
    display: block;
    color: #ff7e00;
    padding: 15px;
    text-decoration: none;
    /* 取消a链接的下划线效果 */
}

nav a:hover {
    background-color: rgba(255, 193, 8, 0.3);
    font-weight: bold;
}


nav li:nth-child(n+2) {
    border-left: 1px solid rgba(255, 161, 39, 0.741);
}

br+span {
    font-size: 0.7em;
    color: #ffab0e;
}

/* ###############
06.自适应样式 
##################*/

/* 炒鸡小屏手机 (phones, 600px and down) */

@media only screen and (max-width: 600px) {

    nav {
        margin-top: 1px;
    }

    nav ul {
        flex-flow: column;
    }

    nav li:nth-child(n+2) {
        border-left-style: none;
        border-top: 1px solid rgba(255, 255, 255, .7);
    }

}

/* 中等手机以及竖屏平板 (portrait tablets and large phones, 600px and up) */

@media only screen and (min-width: 600px) {}

/* 横屏平板 (landscape tablets, 768px and down) */

@media only screen and (max-width: 768px) {
    
    nav {
        margin-top: 1px;
    }

    nav ul {
        flex-flow: column;
    }

    nav li:nth-child(n+2) {
        border-left-style: none;
        border-top: 1px solid rgba(255, 255, 255, .7);
    }

}

/* 中小型笔记本电脑及台式机 (laptops/desktops, 992px and down) */

@media only screen and (max-width: 992px) {
}

/* 宽屏笔记本及台式机 (large laptops and desktops, 1200px and up) */

@media only screen and (min-width: 1200px) {}