.gradient-blue {
    background-color: transparent;
    background-image: -webkit-gradient(linear, left top, right top, from(#83bced), to(#007bff));
    background-image: -webkit-linear-gradient(left, #83bced, #007bff);
    background-image: -o-linear-gradient(left, #83bced, #007bff);
    background-image: linear-gradient(to right, #83bced, #007bff);
}
main #content img {
    max-width:100%;
    height:auto;
}
/*
-----------
Sidebar Tree
-----------
*/
    /* Remove default bullets */
    ul,
    #sidebar-tree_main {
        list-style-type: none;
    }

    /* Remove margins and padding from the parent ul */
    #sidebar-tree_main {
        margin: 0;
        padding: 0;
    }

    /* Style the caret/arrow */
    .caret {
        cursor: pointer;
        user-select: none;
        /* Prevent text selection */
    }

    /* Create the caret/arrow with a unicode, and style it */
    .caret::before {
        content: "\f105";
        color: black;
        display: inline-block;
        margin-right: 6px;
    }

    /* Rotate the caret/arrow icon when clicked on (using JavaScript) */
    .caret-down::before {
        transform: rotate(90deg);
    }

    /* Hide the nested list */
    .nested {
        display: none;
    }

    /* Show the nested list when the user clicks on the caret/arrow (with JavaScript) */
    .actived {
        display: block;
    }
    .nestedOpen{display: block !important}
    .sidebarTree__remove-padding {
        padding-left: 2em;
    }