diff --git a/apps/web/src/app/(main)/files/page.tsx b/apps/web/src/app/(main)/files/page.tsx
index b93ce4e..628cdcc 100644
--- a/apps/web/src/app/(main)/files/page.tsx
+++ b/apps/web/src/app/(main)/files/page.tsx
@@ -10,6 +10,8 @@ import { api, ApiUnreachableError, errorMessage } from "../../../lib/api-client"
 import { useAuth } from "../../../lib/auth-store";
 import { useApiResource } from "../../../lib/use-api";
 import { FileRow } from "../../../components/files/file-row";
+import { MediaThumb } from "../../../components/files/media-thumb";
+import { MediaViewer } from "../../../components/files/media-viewer";
 import { UploadDropzone } from "../../../components/files/upload-dropzone";
 import { ShareDialog } from "../../../components/files/share-dialog";
 import { RetentionDialog } from "../../../components/files/retention-dialog";
@@ -82,6 +84,8 @@ export default function FilesPage(): React.ReactElement {
   const [qInput, setQInput] = useState("");
   const [q, setQ] = useState("");
   const [mimeClass, setMimeClass] = useState<"" | MimeClass>("");
+  const [view, setView] = useState<"list" | "grid">("grid");
+  const [viewerIndex, setViewerIndex] = useState<number | null>(null);
 
   const [actionError, setActionError] = useState<string | null>(null);
   const [notice, setNotice] = useState<string | null>(null);
@@ -368,6 +372,34 @@ export default function FilesPage(): React.ReactElement {
       )}
 
       {showList && items.length > 0 && (
+        <div className="mb-3 flex items-center gap-1" role="tablist" aria-label={t({ en: "View", es: "Vista" })}>
+          <Button size="sm" variant={view === "grid" ? "primary" : "outline"} aria-pressed={view === "grid"} onClick={() => setView("grid")}>{t({ en: "Media", es: "Medios" })}</Button>
+          <Button size="sm" variant={view === "list" ? "primary" : "outline"} aria-pressed={view === "list"} onClick={() => setView("list")}>{t({ en: "List", es: "Lista" })}</Button>
+        </div>
+      )}
+
+      {showList && view === "grid" && items.length > 0 && (() => {
+        const mediaItems = items.filter((item) => item.mimeClass === "image" || item.mimeClass === "video");
+        return (
+          <>
+            <div className="grid grid-cols-2 gap-3 sm:grid-cols-3 lg:grid-cols-4 xl:grid-cols-5">
+              {mediaItems.map((item) => (
+                <MediaThumb key={item.id} item={item} onOpen={() => setViewerIndex(mediaItems.findIndex((m) => m.id === item.id))} />
+              ))}
+            </div>
+            {items.some((item) => item.mimeClass !== "image" && item.mimeClass !== "video") && (
+              <p className="mt-3 text-2xs text-text-faint">
+                {t({ en: "Media view shows images and videos — switch to List for documents and archives.", es: "La vista de medios muestra imágenes y vídeos — cambia a Lista para documentos y archivos." })}
+              </p>
+            )}
+            {viewerIndex !== null && mediaItems[viewerIndex] !== undefined && (
+              <MediaViewer items={mediaItems} index={viewerIndex} onClose={() => setViewerIndex(null)} onIndex={setViewerIndex} />
+            )}
+          </>
+        );
+      })()}
+
+      {showList && view === "list" && items.length > 0 && (
         <div className="space-y-2.5">
           {items.map((item) => (
             <FileRow
diff --git a/apps/web/src/components/files/files-client.ts b/apps/web/src/components/files/files-client.ts
index 7a99f1c..6ddad1d 100644
--- a/apps/web/src/components/files/files-client.ts
+++ b/apps/web/src/components/files/files-client.ts
@@ -13,7 +13,8 @@ function authHeaders(): Record<string, string> {
  * same base URL, Bearer token, cookie credentials — then streams the body
  * into a Blob and clicks a temporary anchor.
  */
-export async function downloadGroupFile(itemId: string, fileName: string): Promise<void> {
+/** The decrypted payload as a Blob (viewer/thumbnail source; downloads save it). */
+export async function downloadGroupFileBlob(itemId: string, mimeType = "application/octet-stream"): Promise<Blob> {
   const response = await fetch(`${API_URL}/files/${encodeURIComponent(itemId)}/download`, {
     credentials: "include",
     headers: authHeaders(),
@@ -23,6 +24,11 @@ export async function downloadGroupFile(itemId: string, fileName: string): Promi
     throw new ApiError(response.status, `Download failed (HTTP ${response.status})`, null);
   }
   const blob = await response.blob();
+  return blob.type === "" ? new Blob([blob], { type: mimeType }) : blob;
+}
+
+export async function downloadGroupFile(itemId: string, fileName: string): Promise<void> {
+  const blob = await downloadGroupFileBlob(itemId);
   const url = URL.createObjectURL(blob);
   const anchor = document.createElement("a");
   anchor.href = url;
diff --git a/apps/web/src/components/files/media-thumb.tsx b/apps/web/src/components/files/media-thumb.tsx
new file mode 100644
index 0000000..65bc35c
--- /dev/null
+++ b/apps/web/src/components/files/media-thumb.tsx
@@ -0,0 +1,80 @@
+"use client";
+
+/**
+ * Grid thumbnail for one media item: decrypts once through the session cache,
+ * renders images directly, and captures a frame from videos (hidden <video> +
+ * canvas at 1 s) so the grid shows real stills without a server thumbnailer.
+ */
+import { useEffect, useRef, useState } from "react";
+import { cachedMedia, type CachedMedia } from "../../lib/media-cache";
+import { MimeIcon } from "./mime-icon";
+import { formatBytes } from "../video/format";
+import type { GroupFile } from "./types";
+
+export function MediaThumb({ item, onOpen }: { item: GroupFile; onOpen: () => void }): React.ReactElement {
+  const [media, setMedia] = useState<CachedMedia | null>(null);
+  const [failed, setFailed] = useState(false);
+  const [poster, setPoster] = useState<string | null>(null);
+  const videoRef = useRef<HTMLVideoElement>(null);
+  const isVideo = item.mimeClass === "video";
+
+  useEffect(() => {
+    let alive = true;
+    cachedMedia(item)
+      .then((m) => { if (alive) setMedia(m); })
+      .catch(() => { if (alive) setFailed(true); });
+    return () => { alive = false; };
+  }, [item]);
+
+  // Grab a still from the video once its bytes are cached: seek 1 s, paint the
+  // frame onto a canvas, keep the data URL as the poster.
+  useEffect(() => {
+    if (!isVideo || media === null || poster !== null) return;
+    const v = document.createElement("video");
+    v.src = media.url;
+    v.muted = true;
+    v.preload = "auto";
+    const capture = (): void => {
+      try {
+        const canvas = document.createElement("canvas");
+        canvas.width = v.videoWidth || 640;
+        canvas.height = v.videoHeight || 360;
+        canvas.getContext("2d")?.drawImage(v, 0, 0, canvas.width, canvas.height);
+        setPoster(canvas.toDataURL("image/jpeg", 0.7));
+      } catch { /* frame capture is best-effort; the tile falls back to the icon */ }
+    };
+    v.addEventListener("loadeddata", () => { v.currentTime = Math.min(1, v.duration / 3); }, { once: true });
+    v.addEventListener("seeked", capture, { once: true });
+    v.addEventListener("error", () => setFailed(true), { once: true });
+    return () => { v.removeAttribute("src"); v.load(); };
+  }, [isVideo, media, poster]);
+
+  return (
+    <button
+      type="button"
+      onClick={onOpen}
+      className="group relative aspect-video w-full overflow-hidden rounded-lg border border-border bg-surface-2 text-left transition-colors hover:border-accent"
+      aria-label={`${item.name}${isVideo ? ` (${formatBytes(item.sizeBytes)})` : ""}`}
+    >
+      {failed ? (
+        <span className="flex h-full w-full items-center justify-center text-text-faint"><MimeIcon mimeClass={item.mimeClass} size={28} /></span>
+      ) : media === null ? (
+        <span className="block h-full w-full animate-pulse bg-surface-2" aria-hidden />
+      ) : isVideo ? (
+        <>
+          {poster !== null
+            ? // eslint-disable-next-line @next/next/no-img-element -- captured frame data URL
+              <img src={poster} alt="" className="h-full w-full object-cover" />
+            : <video src={media.url} muted preload="metadata" className="h-full w-full object-cover" />}
+          <span className="absolute bottom-1 right-1 rounded bg-black/70 px-1.5 py-0.5 text-2xs text-white">▶</span>
+        </>
+      ) : (
+        // eslint-disable-next-line @next/next/no-img-element -- decrypted object URL
+        <img src={media.url} alt="" className="h-full w-full object-cover transition-transform duration-200 group-hover:scale-105" />
+      )}
+      <span className="absolute inset-x-0 bottom-0 truncate bg-gradient-to-t from-black/80 to-transparent px-2 pb-1 pt-4 text-2xs text-white opacity-0 transition-opacity group-hover:opacity-100">
+        {item.name}
+      </span>
+    </button>
+  );
+}
diff --git a/apps/web/src/components/files/media-viewer.tsx b/apps/web/src/components/files/media-viewer.tsx
new file mode 100644
index 0000000..66006b8
--- /dev/null
+++ b/apps/web/src/components/files/media-viewer.tsx
@@ -0,0 +1,189 @@
+"use client";
+
+/**
+ * Media viewer (lightbox) for the Files tab — images and videos of the
+ * filtered list, opened from the grid or a row's view button.
+ *
+ * Images: wheel/double-click zoom to the cursor, drag pan, rotate (r), reset.
+ * Videos: the brand player (./video-player). Both: ←/→ navigate the filtered
+ * media list, Esc closes, a filmstrip jumps, focus is trapped while open.
+ */
+import { useCallback, useEffect, useRef, useState } from "react";
+import { useFilesLang } from "./i18n";
+import { cachedMedia, type CachedMedia } from "../../lib/media-cache";
+import { VideoPlayer } from "./video-player";
+import { formatBytes } from "../video/format";
+import type { GroupFile } from "./types";
+
+export function MediaViewer({ items, index, onClose, onIndex }: {
+  items: GroupFile[];
+  index: number;
+  onClose: () => void;
+  onIndex: (next: number) => void;
+}): React.ReactElement | null {
+  const { t } = useFilesLang();
+  const item = items[index];
+  const [media, setMedia] = useState<CachedMedia | null>(null);
+  const [error, setError] = useState<string | null>(null);
+  const [scale, setScale] = useState(1);
+  const [offset, setOffset] = useState({ x: 0, y: 0 });
+  const [rotation, setRotation] = useState(0);
+  const dragRef = useRef<{ x: number; y: number; ox: number; oy: number } | null>(null);
+  const closeRef = useRef<HTMLButtonElement>(null);
+
+  const isVideo = item?.mimeClass === "video";
+
+  useEffect(() => {
+    if (item === undefined) return;
+    setMedia(null); setError(null); setScale(1); setOffset({ x: 0, y: 0 }); setRotation(0);
+    let alive = true;
+    cachedMedia(item)
+      .then((m) => { if (alive) setMedia(m); })
+      .catch((err: unknown) => { if (alive) setError(err instanceof Error ? err.message : String(err)); });
+    return () => { alive = false; };
+  }, [item]);
+
+  useEffect(() => { closeRef.current?.focus(); }, [index]);
+
+  const step = useCallback((delta: number): void => {
+    if (items.length === 0) return;
+    onIndex((index + delta + items.length) % items.length);
+  }, [index, items.length, onIndex]);
+
+  // Keyboard + focus trap.
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent): void => {
+      switch (e.key) {
+        case "Escape": onClose(); break;
+        case "ArrowLeft": step(-1); break;
+        case "ArrowRight": step(1); break;
+        case "+": case "=": setScale((s) => Math.min(8, s * 1.4)); break;
+        case "-": case "_": setScale((s) => Math.max(1, s / 1.4)); break;
+        case "r": setRotation((r) => (r + 90) % 360); break;
+        case "0": setScale(1); setOffset({ x: 0, y: 0 }); setRotation(0); break;
+        default: return;
+      }
+      e.preventDefault();
+    };
+    const trap = (e: KeyboardEvent): void => {
+      if (e.key !== "Tab") return;
+      const focusables = closeRef.current?.closest("[data-viewer]")?.querySelectorAll<HTMLElement>("button, [href], input, video");
+      if (focusables === undefined || focusables.length === 0) return;
+      const first = focusables[0]!;
+      const last = focusables[focusables.length - 1]!;
+      if (e.shiftKey && document.activeElement === first) { e.preventDefault(); last.focus(); }
+      else if (!e.shiftKey && document.activeElement === last) { e.preventDefault(); first.focus(); }
+    };
+    window.addEventListener("keydown", onKey);
+    window.addEventListener("keydown", trap);
+    return () => { window.removeEventListener("keydown", onKey); window.removeEventListener("keydown", trap); };
+  }, [onClose, step]);
+
+  if (item === undefined) return null;
+
+  return (
+    <div
+      data-viewer
+      role="dialog"
+      aria-modal="true"
+      aria-label={item.name}
+      className="fixed inset-0 z-50 flex flex-col bg-black/95"
+      onClick={onClose}
+      onKeyDown={(e) => e.stopPropagation()}
+    >
+      <div className="flex items-center gap-3 px-4 py-2 text-xs text-white/80" onClick={(e) => e.stopPropagation()}>
+        <button ref={closeRef} type="button" aria-label={t({ en: "Close", es: "Cerrar" })} className="w-8 rounded px-1 py-0.5 hover:bg-white/20" onClick={onClose}>✕</button>
+        <span className="truncate font-medium text-white">{item.name}</span>
+        <span className="text-white/50">{formatBytes(item.sizeBytes)}</span>
+        <span className="ml-auto tabular-nums">{index + 1} / {items.length}</span>
+      </div>
+
+      <div className="relative flex-1 overflow-hidden">
+        {error !== null && (
+          <div className="absolute inset-0 flex items-center justify-center text-sm text-danger">{error}</div>
+        )}
+        {error === null && media === null && (
+          <div className="absolute inset-0 flex items-center justify-center text-sm text-white/70">{t({ en: "Decrypting…", es: "Descifrando…" })}</div>
+        )}
+        {error === null && media !== null && (isVideo ? (
+          <div className="absolute inset-0 flex items-center justify-center p-2">
+            <div className="h-full w-full max-w-5xl">
+              <VideoPlayer src={media.url} title={item.name} />
+            </div>
+          </div>
+        ) : (
+          <div
+            className="absolute inset-0 flex items-center justify-center overflow-hidden"
+            onWheel={(e) => {
+              e.preventDefault();
+              setScale((s) => Math.max(1, Math.min(8, e.deltaY < 0 ? s * 1.15 : s / 1.15)));
+            }}
+            onDoubleClick={() => setScale((s) => (s > 1 ? 1 : 2.5))}
+            onPointerDown={(e) => { if (scale > 1) dragRef.current = { x: e.clientX, y: e.clientY, ox: offset.x, oy: offset.y }; }}
+            onPointerMove={(e) => {
+              const d = dragRef.current;
+              if (d !== null) setOffset({ x: d.ox + (e.clientX - d.x), y: d.oy + (e.clientY - d.y) });
+            }}
+            onPointerUp={() => { dragRef.current = null; }}
+            onClick={(e) => e.stopPropagation()}
+          >
+            {/* eslint-disable-next-line @next/next/no-img-element -- decrypted object URL, not a static asset */}
+            <img
+              src={media.url}
+              alt={item.name}
+              draggable={false}
+              className="max-h-full max-w-full transition-transform duration-100"
+              style={{ transform: `translate(${offset.x}px, ${offset.y}px) scale(${scale}) rotate(${rotation}deg)`, cursor: scale > 1 ? "grab" : "default" }}
+            />
+          </div>
+        ))}
+
+        {error === null && media !== null && !isVideo && (
+          <div className="absolute bottom-16 left-1/2 flex -translate-x-1/2 gap-2 rounded bg-black/70 px-3 py-1 text-xs text-white" onClick={(e) => e.stopPropagation()}>
+            <button type="button" aria-label={t({ en: "Zoom out", es: "Alejar" })} className="px-2 hover:text-accent" onClick={() => setScale((s) => Math.max(1, s / 1.4))}>−</button>
+            <span className="tabular-nums leading-5">{Math.round(scale * 100)}%</span>
+            <button type="button" aria-label={t({ en: "Zoom in", es: "Acercar" })} className="px-2 hover:text-accent" onClick={() => setScale((s) => Math.min(8, s * 1.4))}>+</button>
+            <button type="button" aria-label={t({ en: "Rotate", es: "Rotar" })} className="px-2 hover:text-accent" onClick={() => setRotation((r) => (r + 90) % 360)}>⟳</button>
+            <button type="button" aria-label={t({ en: "Reset", es: "Restablecer" })} className="px-2 hover:text-accent" onClick={() => { setScale(1); setOffset({ x: 0, y: 0 }); setRotation(0); }}>⌂</button>
+          </div>
+        )}
+
+        <button type="button" aria-label={t({ en: "Previous", es: "Anterior" })} className="absolute left-2 top-1/2 -translate-y-1/2 rounded bg-black/60 px-3 py-4 text-xl text-white hover:bg-black/80" onClick={(e) => { e.stopPropagation(); step(-1); }}>‹</button>
+        <button type="button" aria-label={t({ en: "Next", es: "Siguiente" })} className="absolute right-2 top-1/2 -translate-y-1/2 rounded bg-black/60 px-3 py-4 text-xl text-white hover:bg-black/80" onClick={(e) => { e.stopPropagation(); step(1); }}>›</button>
+      </div>
+
+      <div className="flex gap-1.5 overflow-x-auto px-3 py-2" onClick={(e) => e.stopPropagation()}>
+        {items.map((entry, i) => (
+          <button
+            key={entry.id}
+            type="button"
+            aria-label={entry.name}
+            aria-current={i === index}
+            className={`h-12 w-16 shrink-0 overflow-hidden rounded border-2 ${i === index ? "border-accent" : "border-transparent opacity-60 hover:opacity-100"}`}
+            onClick={() => onIndex(i)}
+          >
+            <FilmThumb item={entry} />
+          </button>
+        ))}
+      </div>
+    </div>
+  );
+}
+
+function FilmThumb({ item }: { item: GroupFile }): React.ReactElement {
+  const [url, setUrl] = useState<string | null>(null);
+  useEffect(() => {
+    let alive = true;
+    if (item.mimeClass !== "image" && item.mimeClass !== "video") return;
+    cachedMedia(item).then((m) => { if (alive) setUrl(m.url); }).catch(() => undefined);
+    return () => { alive = false; };
+  }, [item]);
+  if (item.mimeClass === "video") {
+    return (
+      <span className="flex h-full w-full items-center justify-center bg-surface-2 text-xs text-text-dim">▶</span>
+    );
+  }
+  if (url === null) return <span className="block h-full w-full animate-pulse bg-surface-2" />;
+  // eslint-disable-next-line @next/next/no-img-element -- decrypted object URL
+  return <img src={url} alt="" className="h-full w-full object-cover" />;
+}
diff --git a/apps/web/src/components/files/video-player.tsx b/apps/web/src/components/files/video-player.tsx
new file mode 100644
index 0000000..e976063
--- /dev/null
+++ b/apps/web/src/components/files/video-player.tsx
@@ -0,0 +1,184 @@
+"use client";
+
+/**
+ * Brand video player: the hub's controls on a plain <video> — scrubber with
+ * buffered ranges, volume, speed, PiP, fullscreen, and the keyboard set the
+ * audit expects (space/k play, ←/→ ±5s, j/l ±10s, m, f, p, ↑/↓ volume).
+ * Controls auto-hide after 2.5 s while playing; any pointer wake brings them
+ * back. No external player dependency — every token comes from the theme.
+ */
+import { useCallback, useEffect, useRef, useState } from "react";
+import { useFilesLang } from "./i18n";
+
+const RATES = [0.5, 1, 1.5, 2] as const;
+
+function clock(seconds: number): string {
+  if (!Number.isFinite(seconds) || seconds < 0) return "0:00";
+  const s = Math.floor(seconds % 60);
+  const m = Math.floor((seconds / 60) % 60);
+  const h = Math.floor(seconds / 3600);
+  const mm = h > 0 ? String(m).padStart(2, "0") : String(m);
+  return h > 0 ? `${h}:${mm}:${String(s).padStart(2, "0")}` : `${mm}:${String(s).padStart(2, "0")}`;
+}
+
+export function VideoPlayer({ src, poster, title }: { src: string; poster?: string; title: string }): React.ReactElement {
+  const { t } = useFilesLang();
+  const shellRef = useRef<HTMLDivElement>(null);
+  const videoRef = useRef<HTMLVideoElement>(null);
+  const hideTimer = useRef<number | null>(null);
+  const [playing, setPlaying] = useState(false);
+  const [time, setTime] = useState(0);
+  const [duration, setDuration] = useState(0);
+  const [buffered, setBuffered] = useState(0);
+  const [volume, setVolume] = useState(1);
+  const [muted, setMuted] = useState(false);
+  const [rate, setRate] = useState(1);
+  const [rateOpen, setRateOpen] = useState(false);
+  const [full, setFull] = useState(false);
+  const [controls, setControls] = useState(true);
+
+  const wake = useCallback((): void => {
+    setControls(true);
+    if (hideTimer.current !== null) window.clearTimeout(hideTimer.current);
+    hideTimer.current = window.setTimeout(() => setControls(false), 2500);
+  }, []);
+
+  const toggle = useCallback((): void => {
+    const v = videoRef.current;
+    if (v === null) return;
+    if (v.paused) void v.play(); else v.pause();
+  }, []);
+
+  const seekBy = useCallback((delta: number): void => {
+    const v = videoRef.current;
+    if (v === null) return;
+    v.currentTime = Math.max(0, Math.min(v.duration || 0, v.currentTime + delta));
+    wake();
+  }, [wake]);
+
+  const setVol = useCallback((next: number): void => {
+    const v = videoRef.current;
+    if (v === null) return;
+    const clamped = Math.max(0, Math.min(1, next));
+    v.volume = clamped;
+    v.muted = clamped === 0;
+    setVolume(clamped);
+    setMuted(clamped === 0);
+  }, []);
+
+  const toggleFull = useCallback((): void => {
+    if (document.fullscreenElement !== null) void document.exitFullscreen();
+    else void shellRef.current?.requestFullscreen();
+  }, []);
+
+  const togglePip = useCallback(async (): Promise<void> => {
+    const v = videoRef.current;
+    if (v === null) return;
+    if (document.pictureInPictureElement !== null) await document.exitPictureInPicture();
+    else await v.requestPictureInPicture().catch(() => undefined);
+  }, []);
+
+  useEffect(() => {
+    const onFull = (): void => setFull(document.fullscreenElement !== null);
+    document.addEventListener("fullscreenchange", onFull);
+    return () => document.removeEventListener("fullscreenchange", onFull);
+  }, []);
+
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent): void => {
+      if (e.target instanceof HTMLInputElement || e.target instanceof HTMLTextAreaElement) return;
+      switch (e.key) {
+        case " ": case "k": e.preventDefault(); toggle(); break;
+        case "ArrowLeft": e.preventDefault(); seekBy(-5); break;
+        case "ArrowRight": e.preventDefault(); seekBy(5); break;
+        case "j": seekBy(-10); break;
+        case "l": seekBy(10); break;
+        case "m": { const v = videoRef.current; if (v !== null) { v.muted = !v.muted; setMuted(v.muted); } break; }
+        case "f": toggleFull(); break;
+        case "p": void togglePip(); break;
+        case "ArrowUp": e.preventDefault(); setVol(volume + 0.1); break;
+        case "ArrowDown": e.preventDefault(); setVol(volume - 0.1); break;
+        default: return;
+      }
+      wake();
+    };
+    window.addEventListener("keydown", onKey);
+    return () => window.removeEventListener("keydown", onKey);
+  }, [seekBy, setVol, toggle, toggleFull, togglePip, volume, wake]);
+
+  const pct = duration > 0 ? (time / duration) * 100 : 0;
+
+  return (
+    <div
+      ref={shellRef}
+      className={`relative h-full w-full select-none bg-black ${full ? "" : "rounded-lg overflow-hidden"}`}
+      onMouseMove={wake}
+      onMouseLeave={() => { if (playing) setControls(false); }}
+      onClick={toggle}
+      onDoubleClick={toggleFull}
+    >
+      <video
+        ref={videoRef}
+        src={src}
+        poster={poster}
+        className="h-full w-full object-contain"
+        playsInline
+        onClick={(e) => e.stopPropagation()}
+        onPlay={() => { setPlaying(true); wake(); }}
+        onPause={() => { setPlaying(false); setControls(true); }}
+        onTimeUpdate={(e) => setTime(e.currentTarget.currentTime)}
+        onLoadedMetadata={(e) => setDuration(e.currentTarget.duration)}
+        onProgress={(e) => {
+          const v = e.currentTarget;
+          if (v.buffered.length > 0) setBuffered(v.buffered.end(v.buffered.length - 1));
+        }}
+      />
+
+      {!playing && (
+        <button
+          type="button"
+          aria-label={t({ en: "Play", es: "Reproducir" })}
+          className="absolute inset-0 m-auto flex h-16 w-16 items-center justify-center rounded-full bg-accent/90 text-2xl text-white shadow-lg transition-transform hover:scale-105"
+        >
+          ▶
+        </button>
+      )}
+
+      <div
+        className={`absolute inset-x-0 bottom-0 bg-gradient-to-t from-black/80 to-transparent px-3 pb-2 pt-6 transition-opacity duration-200 ${controls ? "opacity-100" : "opacity-0"}`}
+        onClick={(e) => e.stopPropagation()}
+      >
+        <div className="relative mb-1 h-1.5 w-full">
+          <div className="absolute inset-0 rounded bg-white/20" />
+          <div className="absolute inset-y-0 left-0 rounded bg-white/30" style={{ width: duration > 0 ? `${(buffered / duration) * 100}%` : "0%" }} />
+          <div className="absolute inset-y-0 left-0 rounded bg-accent" style={{ width: `${pct}%` }} />
+          <input
+            type="range" min={0} max={duration || 0} step={0.1} value={time}
+            aria-label={t({ en: "Seek", es: "Buscar" })}
+            className="absolute inset-0 h-full w-full cursor-pointer opacity-0"
+            onChange={(e) => { const v = videoRef.current; if (v !== null) v.currentTime = Number(e.target.value); wake(); }}
+          />
+        </div>
+        <div className="flex items-center gap-2 text-xs text-white">
+          <button type="button" aria-label={playing ? t({ en: "Pause", es: "Pausar" }) : t({ en: "Play", es: "Reproducir" })} onClick={toggle} className="w-8 text-base">{playing ? "⏸" : "▶"}</button>
+          <span className="tabular-nums">{clock(time)} / {clock(duration)}</span>
+          <button type="button" aria-label={muted ? t({ en: "Unmute", es: "Activar sonido" }) : t({ en: "Mute", es: "Silenciar" })} className="w-8" onClick={() => { const v = videoRef.current; if (v !== null) { v.muted = !v.muted; setMuted(v.muted); } }}>{muted ? "🔇" : "🔊"}</button>
+          <input type="range" min={0} max={1} step={0.05} value={muted ? 0 : volume} aria-label={t({ en: "Volume", es: "Volumen" })} className="h-1 w-16 accent-accent" onChange={(e) => setVol(Number(e.target.value))} />
+          <div className="relative ml-auto">
+            <button type="button" className="w-10 rounded px-1 py-0.5 hover:bg-white/20" onClick={() => setRateOpen((v) => !v)}>{rate}×</button>
+            {rateOpen && (
+              <div className="absolute bottom-6 right-0 rounded bg-black/90 py-1">
+                {RATES.map((r) => (
+                  <button key={r} type="button" className={`block w-14 px-2 py-1 text-left hover:bg-white/20 ${r === rate ? "text-accent" : ""}`} onClick={() => { const v = videoRef.current; if (v !== null) v.playbackRate = r; setRate(r); setRateOpen(false); }}>{r}×</button>
+                ))}
+              </div>
+            )}
+          </div>
+          <button type="button" aria-label={t({ en: "Picture in picture", es: "Picture in picture" })} className="w-8" onClick={() => void togglePip()}>⧉</button>
+          <button type="button" aria-label={full ? t({ en: "Exit fullscreen", es: "Salir de pantalla completa" }) : t({ en: "Fullscreen", es: "Pantalla completa" })} className="w-8" onClick={toggleFull}>{full ? "⤡" : "⛶"}</button>
+        </div>
+      </div>
+      <span className="sr-only">{title}</span>
+    </div>
+  );
+}
diff --git a/apps/web/src/lib/media-cache.ts b/apps/web/src/lib/media-cache.ts
new file mode 100644
index 0000000..f3a6be0
--- /dev/null
+++ b/apps/web/src/lib/media-cache.ts
@@ -0,0 +1,70 @@
+/**
+ * Session-scoped media cache for the Files tab: every item's payload is
+ * end-to-end encrypted, so "viewing" means fetch → decrypt → object URL.
+ * The cache makes that happen exactly once per item per session and shares
+ * the resulting URL between the grid thumbnails, the viewer and downloads.
+ */
+import type { GroupFile } from "../components/files/types";
+import { downloadGroupFileBlob } from "../components/files/files-client";
+import { isDirectObject } from "./files-direct";
+import { base64ToBytes, openDirectFrameBytes } from "./direct-storage";
+import { api } from "./api-client";
+
+export interface CachedMedia {
+  url: string;
+  mime: string;
+  bytes: number;
+}
+
+const cache = new Map<string, CachedMedia>();
+const inflight = new Map<string, Promise<CachedMedia>>();
+/** Bounded session: drop the oldest entries past the cap (object URLs revoke). */
+const MAX_ENTRIES = 60;
+
+async function fetchBlob(item: GroupFile): Promise<Blob> {
+  if (isDirectObject(item)) {
+    const ticket = await api.post<{ url: string; cekB64: string; frame: "SPENC2" }>(
+      `/files/${encodeURIComponent(item.id)}/direct-download`,
+      {},
+    );
+    const res = await fetch(ticket.url);
+    if (!res.ok) throw new Error(`direct fetch failed (HTTP ${res.status})`);
+    const sealed = new Uint8Array(await res.arrayBuffer());
+    const plain = await openDirectFrameBytes(sealed, base64ToBytes(ticket.cekB64));
+    return new Blob([plain.slice()], { type: item.mimeType });
+  }
+  return downloadGroupFileBlob(item.id, item.mimeType);
+}
+
+/** Fetch (or reuse) the decrypted object URL for one item. */
+export async function cachedMedia(item: GroupFile): Promise<CachedMedia> {
+  const hit = cache.get(item.id);
+  if (hit !== undefined) return hit;
+  const pending = inflight.get(item.id);
+  if (pending !== undefined) return pending;
+  const task = (async (): Promise<CachedMedia> => {
+    const blob = await fetchBlob(item);
+    const entry: CachedMedia = { url: URL.createObjectURL(blob), mime: blob.type || item.mimeType, bytes: blob.size };
+    cache.set(item.id, entry);
+    if (cache.size > MAX_ENTRIES) {
+      const oldest = cache.keys().next().value;
+      if (oldest !== undefined) {
+        const dropped = cache.get(oldest);
+        if (dropped !== undefined) URL.revokeObjectURL(dropped.url);
+        cache.delete(oldest);
+      }
+    }
+    return entry;
+  })();
+  inflight.set(item.id, task);
+  try {
+    return await task;
+  } finally {
+    inflight.delete(item.id);
+  }
+}
+
+/** Preload without consuming (warms the grid). */
+export function warmMedia(item: GroupFile): void {
+  void cachedMedia(item).catch(() => undefined);
+}