.junkao-header-box {
    width: 100%;
    display: flex;
    justify-content: center;
    background-color: #282828;
    height: 60px;
}

.junkao-header-wrap {
    width: 1200px;
    height: 66px;
    color: #FFFFFF;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.junkao-header-left {
    display: flex;
    align-items: center;
}

.junkao-header-left span {
    margin-left: 30px;
    padding: 10px 20px;
    cursor: pointer;
}

.junkao-header-left span:hover {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px 4px 4px 4px;
}

.junkao-header-right {
    display: flex;
    align-items: center;
}

.user-msg {
    display: flex;
    align-items: center;
    cursor: pointer;
}

.user-msg img {
    width: 30px;
    height: 30px;
    border-radius: 100%;
    margin-right: 5px;
}

.study-center {
    padding: 10px 20px;
}

.study-center:hover {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px 4px 4px 4px;
}

#dropdown-menu {
    overflow: hidden;
    height: 0;
    background-color: #fff; /* 添加背景色 */
    border: 1px solid #ccc; /* 可以添加边框等样式 */
}

.dropdown-item {
    padding: 10px;
    cursor: pointer;
    /* 这里可以添加其他样式 */
    text-decoration: none;
    display: block;
    color: #333;
}

.dropdown-item:hover {
    background-color: #f1f1f1;
}