diff --git a/frontend/src/app/documents/page.tsx b/frontend/src/app/documents/page.tsx
index 48e5bbd9..aa6f263c 100644
--- a/frontend/src/app/documents/page.tsx
+++ b/frontend/src/app/documents/page.tsx
@@ -62,6 +62,99 @@ function formatDate(value?: string): string {
   });
 }
 
+const DOCUMENT_PREVIEW_EXTENSIONS = new Set([
+  "pdf",
+  "jpg",
+  "jpeg",
+  "png",
+  "gif",
+  "webp",
+  "svg",
+  "bmp",
+  "ico",
+  "avif",
+  "docx",
+  "xls",
+  "xlsx",
+  "xlsm",
+  "xlsb",
+  "ods",
+  "csv",
+  "tsv",
+  "txt",
+  "text",
+  "md",
+  "markdown",
+  "json",
+  "xml",
+  "html",
+  "htm",
+  "css",
+  "scss",
+  "sass",
+  "less",
+  "js",
+  "jsx",
+  "ts",
+  "tsx",
+  "mjs",
+  "cjs",
+  "yml",
+  "yaml",
+  "ini",
+  "conf",
+  "cfg",
+  "log",
+  "sql",
+  "py",
+  "java",
+  "c",
+  "cpp",
+  "h",
+  "hpp",
+  "cs",
+  "go",
+  "rs",
+  "php",
+  "rb",
+  "kt",
+  "kts",
+  "swift",
+  "sh",
+  "bash",
+  "zsh",
+  "ps1",
+  "bat",
+  "cmd",
+  "properties",
+  "env",
+  "rtf",
+  "mp4",
+  "webm",
+  "ogg",
+  "ogv",
+  "mov",
+  "m4v",
+  "mp3",
+  "wav",
+  "oga",
+  "m4a",
+  "aac",
+  "flac",
+]);
+const DOCUMENT_PREVIEW_FILE_NAMES = new Set(["dockerfile", "makefile", "readme", "license", ".gitignore", ".env"]);
+
+function getDocumentFileExtension(fileName?: string | null): string {
+  const cleanName = (fileName || "").toLowerCase().split("?")[0].split("#")[0];
+  return cleanName.match(/\.([^.]+)$/)?.[1] || "";
+}
+
+function canPreviewDocument(fileName?: string | null): boolean {
+  const lowerName = (fileName || "").toLowerCase();
+  const extension = getDocumentFileExtension(fileName);
+  return DOCUMENT_PREVIEW_EXTENSIONS.has(extension) || DOCUMENT_PREVIEW_FILE_NAMES.has(lowerName);
+}
+
 function formatFileSize(value?: number): string {
   if (!value || value <= 0) return "";
   if (value < 1024) return `${value} Б`;
@@ -549,12 +642,17 @@ function DocumentsPageContent() {
     setDocumentMenuOpenId(null);
   };
 
-  const openDocumentPdfFromMenu = (documentItem: Document) => {
+  const openDocumentPreviewFromMenu = (documentItem: Document) => {
     if (!documentItem.file_url) return;
-    setPdfViewerFile({
+    const previewFile = {
       url: documentItem.file_url,
       name: documentItem.file_name || documentItem.title,
-    });
+    };
+    if (getDocumentFileExtension(documentItem.file_name) === "pdf") {
+      setPdfViewerFile(previewFile);
+    } else {
+      setPreviewFile(previewFile);
+    }
     setDocumentMenuOpenId(null);
   };
 
@@ -1129,7 +1227,7 @@ function DocumentsPageContent() {
                           const fileSize = formatFileSize(doc.file_size);
                           const recipientsCount = doc.recipients?.length || 0;
                           const departmentsCount = doc.departments?.length || 0;
-                          const hasPreview = Boolean(doc.file_url && doc.file_name?.toLowerCase().endsWith(".pdf"));
+                          const hasPreview = Boolean(doc.file_url && canPreviewDocument(doc.file_name || doc.title));
 
                           // DEBUG: Проверка данных документа
                           if (!authorName || !createdDate) {
@@ -1309,11 +1407,11 @@ function DocumentsPageContent() {
                                               {hasPreview && (
                                                 <button
                                                   type="button"
-                                                  onClick={() => openDocumentPdfFromMenu(doc)}
+                                                  onClick={() => openDocumentPreviewFromMenu(doc)}
                                                   className="flex w-full items-center gap-2 px-3 py-2 text-left text-sm text-[var(--foreground)] transition hover:bg-[var(--surface-secondary)]"
                                                 >
                                                   <Eye size={14} />
-                                                  Открыть PDF
+                                                  Предпросмотр
                                                 </button>
                                               )}
 
diff --git a/frontend/src/components/documents/DocumentDetailModal.tsx b/frontend/src/components/documents/DocumentDetailModal.tsx
index 8370dd33..606f69a7 100644
--- a/frontend/src/components/documents/DocumentDetailModal.tsx
+++ b/frontend/src/components/documents/DocumentDetailModal.tsx
@@ -28,13 +28,13 @@ import {
 import { DocumentAcknowledgement } from "./DocumentAcknowledgement";
 import { DocumentComments } from "./DocumentComments";
 import { DocumentRelated } from "./DocumentRelated";
+import { DocumentPreviewPane } from "./DocumentPreview";
 
 interface DocumentDetailModalProps {
   document: Document | null;
   isOpen: boolean;
   onClose: () => void;
   onUpdate?: () => void;
-  onPreview?: (url: string, name: string) => void;
   onEditMetadata?: () => void;
   onViewReport?: () => void;
   onNavigateToRelated?: (docId: number) => void;
@@ -47,7 +47,6 @@ export function DocumentDetailModal({
   isOpen,
   onClose,
   onUpdate,
-  onPreview,
   onEditMetadata,
   onViewReport,
   onNavigateToRelated,
@@ -94,41 +93,11 @@ export function DocumentDetailModal({
       );
     }
 
-    const fileExt = document.file_name?.toLowerCase().split(".").pop() || "";
-    const isImage = ["jpg", "jpeg", "png", "gif", "webp", "svg", "bmp"].includes(fileExt);
-    const isPDF = fileExt === "pdf";
-
-    if (isImage) {
-      return (
-        <div className="flex h-full items-center justify-center bg-[var(--background)] p-4">
-          <img
-            src={document.file_url}
-            alt={document.file_name || "Preview"}
-            className="max-h-full max-w-full object-contain"
-          />
-        </div>
-      );
-    }
-
-    if (isPDF) {
-      return (
-        <iframe
-          src={`${document.file_url}#page=1&view=FitH`}
-          className="h-full w-full border-0"
-          title="PDF Preview"
-        />
-      );
-    }
-
     return (
-      <div className="app-surface-muted flex h-full items-center justify-center">
-        <div className="text-center">
-          <FileText size={64} className="app-text-muted mx-auto" />
-          <p className="mt-4 text-sm font-medium text-[var(--foreground)]">{document.file_name}</p>
-          <p className="app-text-muted mt-1 text-xs uppercase">{fileExt} файл</p>
-          <p className="app-text-muted mt-3 text-xs">Предпросмотр недоступен</p>
-        </div>
-      </div>
+      <DocumentPreviewPane
+        fileUrl={document.file_url}
+        fileName={document.file_name || document.title}
+      />
     );
   };
 
diff --git a/frontend/src/components/documents/DocumentPreview.tsx b/frontend/src/components/documents/DocumentPreview.tsx
index c1cef1f5..8f9e5f54 100644
--- a/frontend/src/components/documents/DocumentPreview.tsx
+++ b/frontend/src/components/documents/DocumentPreview.tsx
@@ -1,14 +1,15 @@
 "use client";
 
-import { useState, useEffect } from "react";
+import { useEffect, useMemo, useState } from "react";
 import { Document as PDFDocument, Page, pdfjs } from "react-pdf";
-import { ChevronLeft, ChevronRight, Download, X, FileText, Table } from "lucide-react";
+import { ChevronLeft, ChevronRight, Download, FileAudio, FileText, FileVideo, Table, X } from "lucide-react";
 import "react-pdf/dist/Page/AnnotationLayer.css";
 import "react-pdf/dist/Page/TextLayer.css";
 import { Modal } from "@/components/ui";
 
-// Configure PDF.js worker
-pdfjs.GlobalWorkerOptions.workerSrc = `//unpkg.com/pdfjs-dist@${pdfjs.version}/build/pdf.worker.min.mjs`;
+if (typeof window !== "undefined") {
+  pdfjs.GlobalWorkerOptions.workerSrc = "/pdf.worker.min.mjs";
+}
 
 interface DocumentPreviewProps {
   fileUrl: string;
@@ -16,409 +17,525 @@ interface DocumentPreviewProps {
   onClose?: () => void;
 }
 
+interface DocumentPreviewPaneProps {
+  fileUrl: string;
+  fileName: string;
+  className?: string;
+}
+
 interface ExcelSheet {
   name: string;
-  data: any[][];
+  rows: unknown[][];
 }
 
-function getFileType(fileName: string): 'pdf' | 'image' | 'word' | 'excel' | 'text' | 'unknown' {
-  const ext = fileName.toLowerCase().split('.').pop() || '';
-  
-  if (ext === 'pdf') return 'pdf';
-  if (['jpg', 'jpeg', 'png', 'gif', 'webp', 'svg', 'bmp'].includes(ext)) return 'image';
-  if (['doc', 'docx'].includes(ext)) return 'word';
-  if (['xls', 'xlsx'].includes(ext)) return 'excel';
-  if (['txt', 'csv', 'json', 'xml', 'html', 'css', 'js', 'ts', 'md'].includes(ext)) return 'text';
-  
-  return 'unknown';
+type PreviewType = "pdf" | "image" | "word" | "spreadsheet" | "text" | "video" | "audio" | "unsupported";
+
+const IMAGE_EXTENSIONS = new Set(["jpg", "jpeg", "png", "gif", "webp", "svg", "bmp", "ico", "avif"]);
+const WORD_EXTENSIONS = new Set(["docx"]);
+const SPREADSHEET_EXTENSIONS = new Set(["xls", "xlsx", "xlsm", "xlsb", "ods", "csv", "tsv"]);
+const VIDEO_EXTENSIONS = new Set(["mp4", "webm", "ogv", "mov", "m4v"]);
+const AUDIO_EXTENSIONS = new Set(["mp3", "wav", "ogg", "oga", "m4a", "aac", "flac", "webm"]);
+const TEXT_EXTENSIONS = new Set([
+  "txt",
+  "text",
+  "md",
+  "markdown",
+  "json",
+  "xml",
+  "html",
+  "htm",
+  "css",
+  "scss",
+  "sass",
+  "less",
+  "js",
+  "jsx",
+  "ts",
+  "tsx",
+  "mjs",
+  "cjs",
+  "yml",
+  "yaml",
+  "ini",
+  "conf",
+  "cfg",
+  "log",
+  "sql",
+  "py",
+  "java",
+  "c",
+  "cpp",
+  "h",
+  "hpp",
+  "cs",
+  "go",
+  "rs",
+  "php",
+  "rb",
+  "kt",
+  "kts",
+  "swift",
+  "sh",
+  "bash",
+  "zsh",
+  "ps1",
+  "bat",
+  "cmd",
+  "properties",
+  "env",
+  "rtf",
+]);
+const TEXT_FILE_NAMES = new Set(["dockerfile", "makefile", "readme", "license", ".gitignore", ".env"]);
+
+function getFileExtension(fileName: string): string {
+  const cleanName = fileName.toLowerCase().split("?")[0].split("#")[0];
+  const match = cleanName.match(/\.([^.]+)$/);
+  return match?.[1] || "";
 }
 
-export function DocumentPreview({ fileUrl, fileName, onClose }: DocumentPreviewProps) {
-  const [numPages, setNumPages] = useState<number>(0);
-  const [pageNumber, setPageNumber] = useState<number>(1);
-  const [loading, setLoading] = useState(true);
+function getPreviewType(fileName: string): PreviewType {
+  const lowerName = fileName.toLowerCase();
+  const extension = getFileExtension(fileName);
+
+  if (extension === "pdf") return "pdf";
+  if (IMAGE_EXTENSIONS.has(extension)) return "image";
+  if (WORD_EXTENSIONS.has(extension)) return "word";
+  if (SPREADSHEET_EXTENSIONS.has(extension)) return "spreadsheet";
+  if (VIDEO_EXTENSIONS.has(extension)) return "video";
+  if (AUDIO_EXTENSIONS.has(extension)) return "audio";
+  if (TEXT_EXTENSIONS.has(extension) || TEXT_FILE_NAMES.has(lowerName)) return "text";
+
+  return "unsupported";
+}
+
+function getAuthHeaders(): Record<string, string> {
+  if (typeof window === "undefined") return {};
+  const token = window.localStorage.getItem("access_token");
+  return token ? { Authorization: `Bearer ${token}` } : {};
+}
+
+async function fetchFile(fileUrl: string): Promise<ArrayBuffer> {
+  const response = await fetch(fileUrl, {
+    credentials: "include",
+    headers: getAuthHeaders(),
+  });
+  if (!response.ok) {
+    throw new Error(`HTTP ${response.status}`);
+  }
+  return response.arrayBuffer();
+}
+
+function decodeText(buffer: ArrayBuffer, extension: string): string {
+  const decoded = new TextDecoder("utf-8").decode(buffer);
+  if (extension === "json") {
+    try {
+      return JSON.stringify(JSON.parse(decoded), null, 2);
+    } catch {
+      return decoded;
+    }
+  }
+  return decoded;
+}
+
+function sanitizeDocxHtml(html: string): string {
+  if (typeof window === "undefined") return html;
+
+  const parsed = new DOMParser().parseFromString(html, "text/html");
+  parsed.querySelectorAll("script, iframe, object, embed, link, meta, style").forEach((node) => node.remove());
+  parsed.querySelectorAll("*").forEach((node) => {
+    Array.from(node.attributes).forEach((attribute) => {
+      const name = attribute.name.toLowerCase();
+      const value = attribute.value.trim().toLowerCase();
+      if (name.startsWith("on") || name === "style" || value.startsWith("javascript:")) {
+        node.removeAttribute(attribute.name);
+      }
+    });
+  });
+
+  return parsed.body.innerHTML;
+}
+
+function LoadingState({ label }: { label: string }) {
+  return (
+    <div className="flex h-full min-h-[240px] items-center justify-center">
+      <div className="h-8 w-8 animate-spin rounded-full border-4 border-[var(--border-subtle)] border-t-[var(--accent-primary)]" />
+      <span className="app-text-muted ml-3 text-sm">{label}</span>
+    </div>
+  );
+}
+
+function ErrorState({ message, fileUrl }: { message: string; fileUrl: string }) {
+  return (
+    <div className="flex h-full min-h-[240px] items-center justify-center p-6">
+      <div className="app-feedback-danger max-w-md rounded-lg p-4 text-sm">
+        <p>{message}</p>
+        <a
+          href={fileUrl}
+          download
+          target="_blank"
+          rel="noopener noreferrer"
+          className="app-action-danger mt-3 inline-flex items-center gap-2 rounded-lg px-3 py-1.5 text-xs font-medium"
+        >
+          <Download size={14} />
+          Скачать файл
+        </a>
+      </div>
+    </div>
+  );
+}
+
+function UnsupportedState({ fileUrl, fileName }: { fileUrl: string; fileName: string }) {
+  const extension = getFileExtension(fileName);
+  return (
+    <div className="app-surface-muted flex h-full min-h-[240px] items-center justify-center p-8">
+      <div className="text-center">
+        <FileText size={56} className="app-text-muted mx-auto mb-4" />
+        <p className="text-sm font-medium text-[var(--foreground)]">{fileName}</p>
+        {extension && <p className="app-text-muted mt-1 text-xs uppercase">{extension} файл</p>}
+        <p className="app-text-muted mt-3 max-w-sm text-xs">
+          Для этого формата нет встроенного предпросмотра. Файл можно скачать и открыть локально.
+        </p>
+        <a
+          href={fileUrl}
+          download
+          target="_blank"
+          rel="noopener noreferrer"
+          className="app-action-primary mt-4 inline-flex items-center gap-2 rounded-lg px-4 py-2 text-sm font-medium"
+        >
+          <Download size={16} />
+          Скачать файл
+        </a>
+      </div>
+    </div>
+  );
+}
+
+export function DocumentPreviewPane({ fileUrl, fileName, className = "" }: DocumentPreviewPaneProps) {
+  const previewType = getPreviewType(fileName);
+  const extension = getFileExtension(fileName);
+  const [numPages, setNumPages] = useState(0);
+  const [pageNumber, setPageNumber] = useState(1);
+  const [loading, setLoading] = useState(previewType !== "unsupported");
   const [error, setError] = useState<string | null>(null);
-  const [docxContent, setDocxContent] = useState<string>('');
+  const [docxContent, setDocxContent] = useState("");
   const [excelSheets, setExcelSheets] = useState<ExcelSheet[]>([]);
-  const [activeSheet, setActiveSheet] = useState<number>(0);
-  const [textContent, setTextContent] = useState<string>('');
+  const [activeSheet, setActiveSheet] = useState(0);
+  const [textContent, setTextContent] = useState("");
 
-  const fileType = getFileType(fileName);
-  
-  // Конвертируем DOCX в HTML на клиенте
-  useEffect(() => {
-    if (fileType === 'word' && fileName.toLowerCase().endsWith('.docx')) {
-      setLoading(true);
-      
-      fetch(fileUrl, {
-        credentials: 'include',
-        headers: {
-          'Authorization': `Bearer ${localStorage.getItem('access_token') || ''}`,
-        },
-      })
-        .then(response => {
-          if (!response.ok) throw new Error(`HTTP ${response.status}`);
-          return response.arrayBuffer();
-        })
-        .then(async (arrayBuffer) => {
-          try {
-            const mammoth = (await import('mammoth')).default;
-            const result = await mammoth.convertToHtml({ arrayBuffer });
-            setDocxContent(result.value);
-            setLoading(false);
-          } catch (err) {
-            console.error('Ошибка конвертации DOCX:', err);
-            setError('Не удалось загрузить документ');
-            setLoading(false);
-          }
-        })
-        .catch(err => {
-          console.error('Ошибка загрузки файла:', err);
-          setError('Не удалось загрузить файл');
-          setLoading(false);
-        });
-    }
-  }, [fileUrl, fileName, fileType]);
-  
-  // Парсим Excel файлы локально
-  useEffect(() => {
-    if (fileType === 'excel') {
-      setLoading(true);
-      
-      fetch(fileUrl, {
-        credentials: 'include',
-        headers: {
-          'Authorization': `Bearer ${localStorage.getItem('access_token') || ''}`,
-        },
-      })
-        .then(response => {
-          if (!response.ok) throw new Error(`HTTP ${response.status}`);
-          return response.arrayBuffer();
-        })
-        .then(async (arrayBuffer) => {
-          try {
-            const XLSX = (await import('xlsx')).default;
-            const workbook = XLSX.read(arrayBuffer, { type: 'array' });
-            
-            const sheets: ExcelSheet[] = workbook.SheetNames.map(sheetName => {
-              const worksheet = workbook.Sheets[sheetName];
-              const data = XLSX.utils.sheet_to_json(worksheet, { header: 1 }) as any[][];
-              return {
-                name: sheetName,
-                data
-              };
-            });
-            
-            setExcelSheets(sheets);
-            setLoading(false);
-          } catch (err) {
-            console.error('Ошибка парсинга Excel:', err);
-            setError('Не удалось загрузить таблицу');
-            setLoading(false);
-          }
-        })
-        .catch(err => {
-          console.error('Ошибка загрузки файла:', err);
-          setError('Не удалось загрузить файл');
-          setLoading(false);
-        });
-    }
-  }, [fileUrl, fileName, fileType]);
-  
-  // Загружаем текстовые файлы
-  useEffect(() => {
-    if (fileType === 'text') {
-      setLoading(true);
-      
-      fetch(fileUrl, {
-        credentials: 'include',
-        headers: {
-          'Authorization': `Bearer ${localStorage.getItem('access_token') || ''}`,
-        },
-      })
-        .then(response => {
-          if (!response.ok) throw new Error(`HTTP ${response.status}`);
-          return response.text();
-        })
-        .then(text => {
-          setTextContent(text);
-          setLoading(false);
-        })
-        .catch(err => {
-          console.error('Ошибка загрузки текстового файла:', err);
-          setError('Не удалось загрузить файл');
-          setLoading(false);
-        });
-    }
-  }, [fileUrl, fileName, fileType]);
+  const pdfSource = useMemo(() => ({
+    url: fileUrl,
+    httpHeaders: getAuthHeaders(),
+    withCredentials: true,
+  }), [fileUrl]);
 
-  function onDocumentLoadSuccess({ numPages }: { numPages: number }) {
-    setNumPages(numPages);
-    setLoading(false);
-  }
+  useEffect(() => {
+    let cancelled = false;
 
-  function onDocumentLoadError(error: Error) {
-    console.error('Error loading PDF:', error);
-    setError('Не удалось загрузить PDF файл');
-    setLoading(false);
-  }
+    setNumPages(0);
+    setPageNumber(1);
+    setError(null);
+    setDocxContent("");
+    setExcelSheets([]);
+    setActiveSheet(0);
+    setTextContent("");
+    setLoading(["pdf", "image", "word", "spreadsheet", "text"].includes(previewType));
+
+    async function loadDocx() {
+      try {
+        const arrayBuffer = await fetchFile(fileUrl);
+        const mammoth = (await import("mammoth")).default;
+        const result = await mammoth.convertToHtml({ arrayBuffer });
+        if (!cancelled) {
+          setDocxContent(sanitizeDocxHtml(result.value));
+          setLoading(false);
+        }
+      } catch (loadError) {
+        console.error("DOCX preview error:", loadError);
+        if (!cancelled) {
+          setError("Не удалось открыть DOCX для предпросмотра");
+          setLoading(false);
+        }
+      }
+    }
+
+    async function loadSpreadsheet() {
+      try {
+        const arrayBuffer = await fetchFile(fileUrl);
+        const XLSX = await import("xlsx");
+        const workbook = XLSX.read(arrayBuffer, { type: "array" });
+        const sheets = workbook.SheetNames.map((sheetName) => {
+          const worksheet = workbook.Sheets[sheetName];
+          const rows = XLSX.utils.sheet_to_json<unknown[]>(worksheet, {
+            header: 1,
+            defval: "",
+            blankrows: false,
+          }) as unknown[][];
+          return { name: sheetName, rows };
+        });
+        if (!cancelled) {
+          setExcelSheets(sheets);
+          setLoading(false);
+        }
+      } catch (loadError) {
+        console.error("Spreadsheet preview error:", loadError);
+        if (!cancelled) {
+          setError("Не удалось открыть таблицу для предпросмотра");
+          setLoading(false);
+        }
+      }
+    }
+
+    async function loadText() {
+      try {
+        const arrayBuffer = await fetchFile(fileUrl);
+        if (!cancelled) {
+          setTextContent(decodeText(arrayBuffer, extension));
+          setLoading(false);
+        }
+      } catch (loadError) {
+        console.error("Text preview error:", loadError);
+        if (!cancelled) {
+          setError("Не удалось открыть текстовый файл");
+          setLoading(false);
+        }
+      }
+    }
+
+    if (previewType === "word") {
+      void loadDocx();
+    } else if (previewType === "spreadsheet") {
+      void loadSpreadsheet();
+    } else if (previewType === "text") {
+      void loadText();
+    } else if (previewType === "video" || previewType === "audio" || previewType === "unsupported") {
+      setLoading(false);
+    }
+
+    return () => {
+      cancelled = true;
+    };
+  }, [extension, fileUrl, previewType]);
 
   const goToPrevPage = () => setPageNumber((prev) => Math.max(prev - 1, 1));
   const goToNextPage = () => setPageNumber((prev) => Math.min(prev + 1, numPages));
 
   return (
-    <Modal isOpen onClose={onClose ?? (() => {})} noHeader noPadding size="xl">
-        {/* Header */}
-        <div className="app-divider flex items-center justify-between border-b px-3 py-3 sm:px-6 sm:py-4">
-          <h3 className="truncate text-sm font-semibold text-[var(--foreground)] sm:text-lg">{fileName}</h3>
-          <div className="flex items-center gap-2">
-            <a
-              href={fileUrl}
-              download
-              target="_blank"
-              rel="noopener noreferrer"
-              className="app-action-secondary rounded-lg p-2"
-              title="Скачать"
-            >
-              <Download size={20} />
-            </a>
-            {onClose && (
-              <button
-                onClick={onClose}
-                className="app-action-secondary rounded-lg p-2"
-                title="Закрыть"
-              >
-                <X size={20} />
-              </button>
-            )}
-          </div>
-        </div>
-
-        {/* Content */}
-        <div className="flex-1 overflow-auto p-6">
-          {fileType === 'pdf' ? (
-            <div className="flex flex-col items-center">
-              {loading && (
-                <div className="flex items-center justify-center py-12">
-                  <div className="h-8 w-8 animate-spin rounded-full border-4 border-[var(--border-subtle)] border-t-[var(--accent-primary)]" />
-                </div>
-              )}
-              
-              {error && (
-                <div className="app-feedback-danger rounded-lg p-4 text-sm">
-                  {error}
-                </div>
-              )}
-
+    <div className={`flex h-full min-h-0 flex-col bg-[var(--surface-secondary)] ${className}`}>
+      {previewType === "pdf" && (
+        <>
+          <div className="min-h-0 flex-1 overflow-auto p-4">
+            {loading && <LoadingState label="Загрузка PDF..." />}
+            {error && <ErrorState message={error} fileUrl={fileUrl} />}
+            <div className="flex justify-center">
               <PDFDocument
-                file={fileUrl}
-                onLoadSuccess={onDocumentLoadSuccess}
-                onLoadError={onDocumentLoadError}
+                file={pdfSource}
+                onLoadSuccess={({ numPages: loadedPages }) => {
+                  setNumPages(loadedPages);
+                  setLoading(false);
+                }}
+                onLoadError={(loadError) => {
+                  console.error("PDF preview error:", loadError);
+                  setError("Не удалось загрузить PDF файл");
+                  setLoading(false);
+                }}
                 loading={null}
               >
                 <Page
                   pageNumber={pageNumber}
-                  renderTextLayer={true}
-                  renderAnnotationLayer={true}
-                  className="shadow-lg"
+                  renderAnnotationLayer
+                  renderTextLayer
+                  className="overflow-hidden rounded-lg shadow-lg"
                 />
               </PDFDocument>
             </div>
-          ) : fileType === 'image' ? (
-            <div className="flex items-center justify-center">
-              <img 
-                src={fileUrl} 
-                alt={fileName}
-                className="max-h-full max-w-full rounded-lg shadow-lg"
-                onLoad={() => setLoading(false)}
-                onError={() => setError('Не удалось загрузить изображение')}
-              />
-            </div>
-          ) : fileType === 'word' ? (
-            <div className="h-full">
-              {loading && (
-                <div className="flex items-center justify-center py-12">
-                  <div className="h-8 w-8 animate-spin rounded-full border-4 border-[var(--border-subtle)] border-t-[var(--accent-primary)]" />
-                  <span className="app-text-muted ml-3 text-sm">Загрузка документа...</span>
-                </div>
-              )}
-              
-              {error && (
-                <div className="app-feedback-danger rounded-lg p-4 text-sm">
-                  {error}
-                  <div className="mt-2">
-                    <a
-                      href={fileUrl}
-                      download
-                      target="_blank"
-                      rel="noopener noreferrer"
-                      className="app-action-danger inline-flex items-center gap-2 rounded-lg px-3 py-1.5 text-xs font-medium"
-                    >
-                      <Download size={14} />
-                      Скачать файл
-                    </a>
-                  </div>
-                </div>
-              )}
-              
-              {!loading && !error && docxContent && (
-                <div className="app-surface rounded-lg p-8">
-                  <div 
-                    className="prose prose-sm max-w-none"
-                    dangerouslySetInnerHTML={{ __html: docxContent }}
-                  />
-                </div>
-              )}
-            </div>
-          ) : fileType === 'excel' ? (
-            <div className="h-full">
-              {loading && (
-                <div className="flex items-center justify-center py-12">
-                  <div className="h-8 w-8 animate-spin rounded-full border-4 border-[var(--border-subtle)] border-t-[var(--accent-primary)]" />
-                  <span className="app-text-muted ml-3 text-sm">Загрузка таблицы...</span>
-                </div>
-              )}
-              
-              {error && (
-                <div className="app-feedback-danger rounded-lg p-4 text-sm">
-                  {error}
-                  <div className="mt-2">
-                    <a
-                      href={fileUrl}
-                      download
-                      target="_blank"
-                      rel="noopener noreferrer"
-                      className="app-action-danger inline-flex items-center gap-2 rounded-lg px-3 py-1.5 text-xs font-medium"
-                    >
-                      <Download size={14} />
-                      Скачать файл
-                    </a>
-                  </div>
-                </div>
-              )}
-              
-              {!loading && !error && excelSheets.length > 0 && (
-                <div className="flex h-full flex-col">
-                  {/* Sheet Tabs */}
-                  {excelSheets.length > 1 && (
-                    <div className="app-divider mb-4 flex gap-2 overflow-x-auto border-b pb-2">
-                      {excelSheets.map((sheet, index) => (
-                        <button
-                          key={index}
-                          onClick={() => setActiveSheet(index)}
-                          className={`flex items-center gap-2 whitespace-nowrap px-4 py-2 text-sm ${
-                            activeSheet === index
-                              ? 'app-pill-active'
-                              : 'app-pill'
-                          }`}
-                        >
-                          <Table size={16} />
-                          {sheet.name}
-                        </button>
-                      ))}
-                    </div>
-                  )}
-                  
-                  {/* Excel Table */}
-                  <div className="app-surface-elevated flex-1 overflow-auto rounded-lg">
-                    <table className="w-full border-collapse text-sm">
-                      <tbody>
-                        {excelSheets[activeSheet]?.data.map((row, rowIndex) => (
-                          <tr key={rowIndex} className="border-b border-[var(--border-subtle)] hover:bg-[var(--surface-secondary)]">
-                            {row.map((cell, cellIndex) => (
-                              <td
-                                key={cellIndex}
-                                className="border-r border-[var(--border-subtle)] px-3 py-2 text-[var(--foreground)] last:border-r-0"
-                              >
-                                {cell !== null && cell !== undefined ? String(cell) : ''}
-                              </td>
-                            ))}
-                          </tr>
-                        ))}
-                      </tbody>
-                    </table>
-                    
-                    {excelSheets[activeSheet]?.data.length === 0 && (
-                      <div className="app-text-muted flex items-center justify-center py-12 text-sm">
-                        Лист пуст
-                      </div>
-                    )}
-                  </div>
-                </div>
-              )}
-            </div>
-          ) : fileType === 'text' ? (
-            <div className="h-full">
-              {loading && (
-                <div className="flex items-center justify-center py-12">
-                  <div className="h-8 w-8 animate-spin rounded-full border-4 border-[var(--border-subtle)] border-t-[var(--accent-primary)]" />
-                  <span className="app-text-muted ml-3 text-sm">Загрузка файла...</span>
-                </div>
-              )}
-              
-              {error && (
-                <div className="app-feedback-danger rounded-lg p-4 text-sm">
-                  {error}
-                </div>
-              )}
-              
-              {!loading && !error && (
-                <div className="app-surface-muted rounded-lg p-4">
-                  <pre className="overflow-auto text-xs text-[var(--foreground)]">
-                    <code>{textContent}</code>
-                  </pre>
-                </div>
-              )}
-            </div>
-          ) : (
-            <div className="app-surface-muted flex items-center justify-center rounded-xl p-12">
-              <div className="text-center">
-                <FileText size={48} className="app-text-muted mx-auto mb-4" />
-                <p className="mb-2 text-sm font-medium text-[var(--foreground)]">
-                  Неизвестный тип файла
-                </p>
-                <p className="app-text-muted mb-4 text-sm">
-                  Предпросмотр недоступен для этого типа файла
-                </p>
-                <a
-                  href={fileUrl}
-                  download
-                  target="_blank"
-                  rel="noopener noreferrer"
-                  className="app-action-primary inline-flex items-center gap-2 rounded-lg px-4 py-2 text-sm font-medium"
-                >
-                  <Download size={16} />
-                  Скачать файл
-                </a>
-              </div>
+          </div>
+          {numPages > 0 && (
+            <div className="app-divider flex shrink-0 items-center justify-between border-t px-4 py-3">
+              <button
+                onClick={goToPrevPage}
+                disabled={pageNumber <= 1}
+                className="app-action-secondary rounded-lg p-2 disabled:cursor-not-allowed disabled:opacity-40"
+                title="Предыдущая страница"
+              >
+                <ChevronLeft size={18} />
+              </button>
+              <span className="app-text-muted text-sm">
+                Страница {pageNumber} из {numPages}
+              </span>
+              <button
+                onClick={goToNextPage}
+                disabled={pageNumber >= numPages}
+                className="app-action-secondary rounded-lg p-2 disabled:cursor-not-allowed disabled:opacity-40"
+                title="Следующая страница"
+              >
+                <ChevronRight size={18} />
+              </button>
             </div>
           )}
+        </>
+      )}
+
+      {previewType === "image" && (
+        <div className="flex h-full min-h-0 items-center justify-center overflow-auto p-4">
+          {loading && <LoadingState label="Загрузка изображения..." />}
+          {error && <ErrorState message={error} fileUrl={fileUrl} />}
+          <img
+            src={fileUrl}
+            alt={fileName}
+            className={`max-h-full max-w-full rounded-lg object-contain shadow-lg ${loading || error ? "hidden" : ""}`}
+            onLoad={() => setLoading(false)}
+            onError={() => {
+              setError("Не удалось загрузить изображение");
+              setLoading(false);
+            }}
+          />
         </div>
+      )}
 
-        {/* PDF Navigation */}
-        {fileType === 'pdf' && numPages > 0 && (
-          <div className="app-divider flex items-center justify-between border-t px-6 py-4">
-            <button
-              onClick={goToPrevPage}
-              disabled={pageNumber <= 1}
-              className="app-action-secondary rounded-lg p-2 disabled:cursor-not-allowed disabled:opacity-40"
-            >
-              <ChevronLeft size={20} />
-            </button>
+      {previewType === "word" && (
+        <div className="h-full min-h-0 overflow-auto p-4 sm:p-6">
+          {loading && <LoadingState label="Загрузка DOCX..." />}
+          {error && <ErrorState message={error} fileUrl={fileUrl} />}
+          {!loading && !error && (
+            <article className="mx-auto min-h-full max-w-4xl rounded-lg bg-white p-6 text-sm leading-relaxed text-slate-900 shadow-lg sm:p-8">
+              {docxContent ? (
+                <div
+                  className="max-w-none [&_a]:text-sky-700 [&_img]:max-w-full [&_li]:my-1 [&_ol]:list-decimal [&_ol]:pl-6 [&_p]:my-3 [&_strong]:font-semibold [&_table]:my-4 [&_table]:w-full [&_table]:border-collapse [&_td]:border [&_td]:border-slate-300 [&_td]:p-2 [&_th]:border [&_th]:border-slate-300 [&_th]:bg-slate-100 [&_th]:p-2 [&_ul]:list-disc [&_ul]:pl-6"
+                  dangerouslySetInnerHTML={{ __html: docxContent }}
+                />
+              ) : (
+                <p className="text-slate-500">В документе нет текстового содержимого для предпросмотра.</p>
+              )}
+            </article>
+          )}
+        </div>
+      )}
 
-            <span className="app-text-muted text-sm">
-              Страница {pageNumber} из {numPages}
-            </span>
+      {previewType === "spreadsheet" && (
+        <div className="flex h-full min-h-0 flex-col p-4">
+          {loading && <LoadingState label="Загрузка таблицы..." />}
+          {error && <ErrorState message={error} fileUrl={fileUrl} />}
+          {!loading && !error && (
+            <>
+              {excelSheets.length > 1 && (
+                <div className="app-divider mb-3 flex shrink-0 gap-2 overflow-x-auto border-b pb-2">
+                  {excelSheets.map((sheet, index) => (
+                    <button
+                      key={sheet.name}
+                      onClick={() => setActiveSheet(index)}
+                      className={`inline-flex items-center gap-2 whitespace-nowrap rounded-lg px-3 py-2 text-sm ${
+                        activeSheet === index ? "app-pill-active" : "app-pill"
+                      }`}
+                    >
+                      <Table size={16} />
+                      {sheet.name}
+                    </button>
+                  ))}
+                </div>
+              )}
+              <div className="app-surface-elevated min-h-0 flex-1 overflow-auto rounded-lg">
+                {excelSheets[activeSheet]?.rows.length ? (
+                  <table className="w-full border-collapse text-sm">
+                    <tbody>
+                      {excelSheets[activeSheet].rows.map((row, rowIndex) => (
+                        <tr key={rowIndex} className="border-b border-[var(--border-subtle)]">
+                          {row.map((cell, cellIndex) => (
+                            <td
+                              key={cellIndex}
+                              className="max-w-[360px] border-r border-[var(--border-subtle)] px-3 py-2 text-[var(--foreground)] last:border-r-0"
+                            >
+                              <span className="block whitespace-pre-wrap break-words">
+                                {cell === null || cell === undefined ? "" : String(cell)}
+                              </span>
+                            </td>
+                          ))}
+                        </tr>
+                      ))}
+                    </tbody>
+                  </table>
+                ) : (
+                  <div className="app-text-muted flex h-full min-h-[220px] items-center justify-center text-sm">
+                    Таблица пуста
+                  </div>
+                )}
+              </div>
+            </>
+          )}
+        </div>
+      )}
 
-            <button
-              onClick={goToNextPage}
-              disabled={pageNumber >= numPages}
-              className="app-action-secondary rounded-lg p-2 disabled:cursor-not-allowed disabled:opacity-40"
-            >
-              <ChevronRight size={20} />
-            </button>
+      {previewType === "text" && (
+        <div className="h-full min-h-0 overflow-auto p-4">
+          {loading && <LoadingState label="Загрузка файла..." />}
+          {error && <ErrorState message={error} fileUrl={fileUrl} />}
+          {!loading && !error && (
+            <pre className="app-surface-elevated min-h-full overflow-auto rounded-lg p-4 text-xs leading-relaxed text-[var(--foreground)]">
+              <code>{textContent}</code>
+            </pre>
+          )}
+        </div>
+      )}
+
+      {previewType === "video" && (
+        <div className="flex h-full min-h-[240px] items-center justify-center p-4">
+          <div className="w-full max-w-5xl">
+            <div className="mb-3 flex items-center gap-2 text-sm text-[var(--foreground)]">
+              <FileVideo size={18} className="app-text-muted" />
+              {fileName}
+            </div>
+            <video src={fileUrl} controls className="max-h-[70vh] w-full rounded-lg bg-black" />
           </div>
-        )}
+        </div>
+      )}
+
+      {previewType === "audio" && (
+        <div className="flex h-full min-h-[240px] items-center justify-center p-8">
+          <div className="app-surface-elevated w-full max-w-xl rounded-xl p-6">
+            <div className="mb-4 flex items-center gap-3">
+              <FileAudio size={28} className="app-text-muted" />
+              <div className="min-w-0">
+                <p className="truncate text-sm font-medium text-[var(--foreground)]">{fileName}</p>
+                <p className="app-text-muted text-xs">Аудиофайл</p>
+              </div>
+            </div>
+            <audio src={fileUrl} controls className="w-full" />
+          </div>
+        </div>
+      )}
+
+      {previewType === "unsupported" && <UnsupportedState fileUrl={fileUrl} fileName={fileName} />}
+    </div>
+  );
+}
+
+export function DocumentPreview({ fileUrl, fileName, onClose }: DocumentPreviewProps) {
+  return (
+    <Modal isOpen onClose={onClose ?? (() => {})} noHeader noPadding size="xl" className="h-[90vh]">
+      <div className="app-divider flex shrink-0 items-center justify-between border-b px-3 py-3 sm:px-6 sm:py-4">
+        <h3 className="truncate text-sm font-semibold text-[var(--foreground)] sm:text-lg">{fileName}</h3>
+        <div className="flex items-center gap-2">
+          <a
+            href={fileUrl}
+            download
+            target="_blank"
+            rel="noopener noreferrer"
+            className="app-action-secondary rounded-lg p-2"
+            title="Скачать"
+          >
+            <Download size={20} />
+          </a>
+          {onClose && (
+            <button
+              onClick={onClose}
+              className="app-action-secondary rounded-lg p-2"
+              title="Закрыть"
+            >
+              <X size={20} />
+            </button>
+          )}
+        </div>
+      </div>
+      <DocumentPreviewPane fileUrl={fileUrl} fileName={fileName} className="flex-1" />
     </Modal>
   );
 }