body {
    font-family: Arial;
    margin: 0;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    padding: 10px;
    background: #333;
    color: #fff;
    display: flex;
    gap: 10px;
    align-items: center;
}

main {
    flex: 1;
    display: flex;
    min-height: 0;
}

#folderList, #fileList {
    width: 15%;
    border-right: 1px solid #ccc;
    overflow-y: auto;
    font-size: 13px;
}

#folderList {
    width: 15%;
}

#fileList {
    width: 35%;
}

    #folderList ul, #fileList ul {
        list-style: none;
        margin: 0;
        padding: 0;
    }

    #folderList li, #fileList li {
        padding: 8px;
        cursor: pointer;
        border-bottom: 1px solid #eee;
    }

        #folderList li:hover, #fileList li:hover {
            background: #f0f0f0;
        }

.active-folder {
    background: #ffe7c4 !important;
    font-weight: bold;
    border-left: 4px solid #ff9800;
}

.active-pdf {
    background: #d0e7ff !important;
    font-weight: bold;
    border-left: 4px solid #1976d2;
}

#viewer {
    flex: 1;
    display: flex;
    flex-direction: column;
}

#viewerHeader {
    padding: 8px;
    border-bottom: 1px solid #ccc;
    background: #f9f9f9;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

#buttonGroup button {
    margin-left: 8px;
    padding: 5px 12px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    color: white;
    font-size: 13px;
}

#approveBtn {
    background: #2e7d32;
}

#rejectBtn {
    background: #c62828;
}

#closeBtn {
    background: #555;
}

#prevBtn, #nextBtn {
    background: #1976d2;
}

#statusText {
    margin: 8px;
    font-weight: bold;
    min-height: 10px;
}

#pdfFrame {
    flex: 1;
    width: 100%;
    border: none;
    display: none;
}

.hidden-panel {
    width: 0 !important;
    min-width: 0 !important;
    opacity: 0;
    overflow: hidden;
    transition: width 0.25s ease, opacity 0.25s ease;
}

#folderList, #fileList {
    transition: width 0.25s ease, opacity 0.25s ease;
}