.pc-style .btn-open-nav {
    display: none;
}

.pc-style .left-nav {
    float: left;
    width: 200px;
    background: #ffffff;
}

.pc-style .left-nav .left-nav-title {
    background: #ff3e3e;
    color: #ffffff;
    padding: 10px;
    text-align: center;
    font-size: 20px;
    font-weight: bold;
}

.pc-style .left-nav .left-nav-title .btn-close-nav {
    display: none;
}

.pc-style .left-nav .left-nav-inner {
    padding: 10px 20px 20px 20px;
    background: #ffffff;
}

.pc-style .left-nav dl {
    padding: 10px 0px;
}

.pc-style .left-nav dt {
    font-size: 18px;
    font-weight: bold;
    color: #666666;
    margin-bottom: 5px;
}

.pc-style .left-nav dd li a {
    color: #333333;
    display: block;
    padding-left: 10px;
    position: relative;
    padding: 5px 0px 5px 10px;
}

.pc-style .left-nav dd li a:before {
    content: "";
    display: block;
    position: absolute;
    left: 0px;
    top: 14px;
    width: 4px;
    height: 4px;
    background: #888888;
    border-radius: 100%;
}

.pc-style .left-nav a:hover {
    color: #cc0000
}


/*****移动端样式*****/

.mobile-style .btn-open-nav {
    position: fixed;
    left: 16px;
    bottom: 78px;
    width: 44px;
    height: 44px;
    background: #ff3e3e url(https://wx.100xuexi.com/images/Mobile_bg0343.png) center center no-repeat;
    background-size: 24px 24px;
    border-radius: 100%;
    z-index: 2000;
    box-shadow: 0px 0px 10px 0px rgba(0, 0, 0, 0.3);
}

.mobile-style .left-nav {
    background: #ffffff;
    position: fixed;
    left: 0px;
    top: 0px;
    right: 0px;
    bottom: 0px;
    z-index: 20000;
    display: none;
}

.mobile-style .left-nav .left-nav-title {
    position: absolute;
    top: 0px;
    left: 0px;
    right: 0px;
    background: #ffffff;
    color: #333333;
    padding: 0px 16px;
    text-align: center;
    font-size: 18px;
    font-weight: normal;
    line-height: 44px;
    border-bottom: 1px solid #e5e5e5;
    z-index: 10;
}

.mobile-style .left-nav .left-nav-title .btn-close-nav {
    position: absolute;
    right: 0px;
    top: 0px;
    width: 44px;
    height: 44px;
    background: url(https://wx.100xuexi.com/images/Mobile_bg0137_0.png) center center no-repeat;
    background-size: 20px 20px;
}

.mobile-style .left-nav .left-nav-inner {
    position: absolute;
    left: 0px;
    top: 44px;
    right: 0px;
    bottom: 0px;
    padding: 10px 20px 20px 20px;
    background: #ffffff;
    z-index: 1;
    overflow: auto;
    -webkit-overflow-scrolling: touch;
}

.mobile-style .left-nav dl {
    padding: 10px 0px;
}

.mobile-style .left-nav dt {
    font-size: 18px;
    font-weight: bold;
    color: #666666;
    margin-bottom: 5px;
}

.mobile-style .left-nav dd li a {
    color: #333333;
    display: block;
    padding-left: 10px;
    position: relative;
    padding: 5px 0px 5px 10px;
    font-size: 16px;
}

.mobile-style .left-nav dd li a:before {
    content: "";
    display: block;
    position: absolute;
    left: 0px;
    top: 14px;
    width: 4px;
    height: 4px;
    background: #888888;
    border-radius: 100%;
}

.mobile-style .left-nav a:hover {
    color: #cc0000
}