diff --git a/internal/service/reader/audio_transcode.go b/internal/service/reader/audio_transcode.go
index 91e6d99..2929c91 100644
--- a/internal/service/reader/audio_transcode.go
+++ b/internal/service/reader/audio_transcode.go
@@ -286,8 +286,12 @@ func (s *ReaderService) transcodeInputHeaders(ctx context.Context, bookID, sourc
 	if ck := state.CookieForRequest(source); ck != "" {
 		headers["Cookie"] = ck
 	}
+	// 默认 Referer 同上：聚合类书源的 origin 是显示名，拼出来的 Referer 非法，
+	// 会被音源/图床判盗链。只在 origin 是真正的 http(s) 地址时才补。
 	if headers["Referer"] == "" {
-		headers["Referer"] = strings.TrimSuffix(book.Origin, "/") + "/"
+		if referer := sourceReferer(book.Origin); referer != "" {
+			headers["Referer"] = referer
+		}
 	}
 	return headers
 }
diff --git a/internal/service/reader/proxy_test.go b/internal/service/reader/proxy_test.go
index 8ce2abb..bc1e892 100644
--- a/internal/service/reader/proxy_test.go
+++ b/internal/service/reader/proxy_test.go
@@ -1,10 +1,16 @@
 package reader
 
 import (
+	"io"
+	"net/http"
+	"net/http/httptest"
 	"net/url"
+	"sync/atomic"
 	"testing"
+	"time"
 
 	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
 )
 
 // TestProxyURLSignRoundTrip 验证媒体代理签名：往返还原 + 防篡改。
@@ -41,3 +47,88 @@ func TestProxyURLSignRoundTrip(t *testing.T) {
 		t.Fatalf("double wrap: %q", again)
 	}
 }
+
+// TestSourceReferer 验证默认 Referer 只在 origin 是真正的 http(s) 书源地址时
+// 才生成。聚合类书源的 origin 是显示名（如「光遇聚合」），拿它当 Referer 会被
+// 图床判盗链，返回一张「请到本网站阅读」的占位图。
+func TestSourceReferer(t *testing.T) {
+	cases := []struct {
+		name   string
+		origin string
+		want   string
+	}{
+		{"普通书源地址", "https://www.example.com", "https://www.example.com/"},
+		{"带尾斜杠", "https://www.example.com/", "https://www.example.com/"},
+		{"带子路径", "https://www.example.com/site", "https://www.example.com/site/"},
+		{"聚合书源显示名", "光遇聚合", ""},
+		{"空值", "", ""},
+		{"只有空白", "   ", ""},
+		{"非 http 协议", "ftp://example.com", ""},
+		{"没有主机", "https://", ""},
+	}
+	for _, c := range cases {
+		if got := sourceReferer(c.origin); got != c.want {
+			t.Errorf("%s: sourceReferer(%q) = %q，期望 %q", c.name, c.origin, got, c.want)
+		}
+	}
+}
+
+// TestFetchMediaRetriesTransientFailure 验证图床偶发 403（并发限流）会被重试掉，
+// 否则漫画一屏并发取图时总有几页留成破图。
+func TestFetchMediaRetriesTransientFailure(t *testing.T) {
+	var hits int32
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if atomic.AddInt32(&hits, 1) < 3 {
+			w.WriteHeader(http.StatusForbidden)
+			return
+		}
+		w.Header().Set("Content-Type", "image/webp")
+		_, _ = w.Write([]byte("real-image-bytes"))
+	}))
+	defer srv.Close()
+
+	s := &ReaderService{http: &http.Client{Timeout: 10 * time.Second}}
+	book := &model.ReaderBook{Origin: srv.URL}
+
+	resp, err := s.FetchMedia(t.Context(), book, srv.URL+"/1.webp", "")
+	if err != nil {
+		t.Fatalf("FetchMedia 失败: %v", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("状态码 = %d，期望 200（前两次 403 应被重试掉）", resp.StatusCode)
+	}
+	data, _ := io.ReadAll(resp.Body)
+	if string(data) != "real-image-bytes" {
+		t.Fatalf("body = %q", data)
+	}
+	if got := atomic.LoadInt32(&hits); got != 3 {
+		t.Fatalf("上游请求次数 = %d，期望 3", got)
+	}
+}
+
+// TestFetchMediaDoesNotRetryNotFound 验证确定性的 4xx（如图片不存在）不做无谓重试，
+// 避免首屏白白多等两轮退避。
+func TestFetchMediaDoesNotRetryNotFound(t *testing.T) {
+	var hits int32
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		atomic.AddInt32(&hits, 1)
+		w.WriteHeader(http.StatusNotFound)
+	}))
+	defer srv.Close()
+
+	s := &ReaderService{http: &http.Client{Timeout: 10 * time.Second}}
+	book := &model.ReaderBook{Origin: srv.URL}
+
+	resp, err := s.FetchMedia(t.Context(), book, srv.URL+"/missing.webp", "")
+	if err != nil {
+		t.Fatalf("FetchMedia 失败: %v", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusNotFound {
+		t.Fatalf("状态码 = %d，期望 404", resp.StatusCode)
+	}
+	if got := atomic.LoadInt32(&hits); got != 1 {
+		t.Fatalf("上游请求次数 = %d，期望 1（404 不该重试）", got)
+	}
+}
diff --git a/internal/service/reader/reader.go b/internal/service/reader/reader.go
index 6dd5a76..397ddb6 100644
--- a/internal/service/reader/reader.go
+++ b/internal/service/reader/reader.go
@@ -1222,49 +1222,127 @@ func (s *ReaderService) VerifyProxyURL(bookID, encoded, sig string) (string, err
 // FetchMedia 服务端拉取媒体资源（携带书源级请求头与 Referer，支持 Range 透传）。
 // 调用方负责关闭 resp.Body。
 func (s *ReaderService) FetchMedia(ctx context.Context, book *model.ReaderBook, rawURL, rangeHeader string) (*http.Response, error) {
-	httpReq, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
-	if err != nil {
-		return nil, err
-	}
-	for k, v := range helper.HTTPHeaderPresets() {
-		httpReq.Header.Set(k, v)
-	}
-	// 媒体流同样交给 net/http 管压缩：否则压缩过的资源会以原始字节透传给
-	// 播放器/图片标签，表现为「打不开」。Range 请求服务端通常不压缩，
-	// 解压后 resp 会去掉 Content-Length/Content-Encoding，透传逻辑不受影响。
-	helper.StripAcceptEncoding(httpReq.Header)
-	// 书源级请求头
-	if s.repo != nil {
-		if found, findErr := s.repo.GetSourceByURL(ctx, book.Origin); findErr == nil && found != nil && found.Header != "" {
-			var headers map[string]any
-			if json.Unmarshal([]byte(found.Header), &headers) == nil {
-				for k, v := range headers {
-					httpReq.Header.Set(k, fmt.Sprintf("%v", v))
+	// 请求构造抽成闭包：http.Request 不可复用，重试时必须重建。
+	buildRequest := func() (*http.Request, error) {
+		httpReq, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
+		if err != nil {
+			return nil, err
+		}
+		for k, v := range helper.HTTPHeaderPresets() {
+			httpReq.Header.Set(k, v)
+		}
+		// 媒体流同样交给 net/http 管压缩：否则压缩过的资源会以原始字节透传给
+		// 播放器/图片标签，表现为「打不开」。Range 请求服务端通常不压缩，
+		// 解压后 resp 会去掉 Content-Length/Content-Encoding，透传逻辑不受影响。
+		helper.StripAcceptEncoding(httpReq.Header)
+		// 书源级请求头
+		if s.repo != nil {
+			if found, findErr := s.repo.GetSourceByURL(ctx, book.Origin); findErr == nil && found != nil && found.Header != "" {
+				var headers map[string]any
+				if json.Unmarshal([]byte(found.Header), &headers) == nil {
+					for k, v := range headers {
+						httpReq.Header.Set(k, fmt.Sprintf("%v", v))
+					}
 				}
 			}
 		}
-	}
-	// 登录态：登录类书源的漫画/音频资源同样需要 Cookie 与 loginHeader 才能取到。
-	if s.repo != nil {
-		state := s.newSourceState(ctx, book.Origin)
-		for k, v := range state.LoginHeaderMap() {
-			if !strings.EqualFold(k, "cookie") && httpReq.Header.Get(k) == "" {
-				httpReq.Header.Set(k, v)
+		// 登录态：登录类书源的漫画/音频资源同样需要 Cookie 与 loginHeader 才能取到。
+		if s.repo != nil {
+			state := s.newSourceState(ctx, book.Origin)
+			for k, v := range state.LoginHeaderMap() {
+				if !strings.EqualFold(k, "cookie") && httpReq.Header.Get(k) == "" {
+					httpReq.Header.Set(k, v)
+				}
+			}
+			if httpReq.Header.Get("Cookie") == "" {
+				if ck := state.CookieForRequest(rawURL); ck != "" {
+					httpReq.Header.Set("Cookie", ck)
+				}
 			}
 		}
-		if httpReq.Header.Get("Cookie") == "" {
-			if ck := state.CookieForRequest(rawURL); ck != "" {
-				httpReq.Header.Set("Cookie", ck)
+		// 默认 Referer 只能用「真正的 http(s) 书源地址」。
+		// legado 的 origin 对普通书源是 bookSourceUrl，但聚合类书源（如「光遇聚合」）
+		// 的 origin 是个显示名，拼出来的 Referer 非法，会被图床判定为盗链并
+		// 301 到一张「请到本网站阅读」的占位图 —— 表现为漫画每一页都是同一张提示图。
+		// 这种情况下宁可不发 Referer（实测不带 Referer 能拿到原图）；书源 header
+		// 里自己声明的 Referer 优先级更高，不受这里影响。
+		if httpReq.Header.Get("Referer") == "" {
+			if referer := sourceReferer(book.Origin); referer != "" {
+				httpReq.Header.Set("Referer", referer)
 			}
 		}
+		if rangeHeader != "" {
+			httpReq.Header.Set("Range", rangeHeader)
+		}
+		return httpReq, nil
 	}
-	if httpReq.Header.Get("Referer") == "" && book.Origin != "" {
-		httpReq.Header.Set("Referer", strings.TrimSuffix(book.Origin, "/")+"/")
+
+	var lastErr error
+	for attempt := 1; attempt <= mediaFetchAttempts; attempt++ {
+		if attempt > 1 {
+			// 图床在高并发拉取时会偶发 403/429（实测同一张图稍后重试即可成功）。
+			// 漫画一屏会并发取多张，零星失败就会在页面上留几个破图，因此做少量退避重试。
+			select {
+			case <-ctx.Done():
+				return nil, ctx.Err()
+			case <-time.After(mediaFetchRetryDelay * time.Duration(attempt-1)):
+			}
+		}
+		httpReq, err := buildRequest()
+		if err != nil {
+			return nil, err
+		}
+		resp, err := s.http.Do(httpReq)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		if attempt == mediaFetchAttempts || !mediaRetryableStatus(resp.StatusCode) {
+			return resp, nil
+		}
+		// 可重试的状态码：读完并关闭响应体再试，避免连接泄漏。
+		lastErr = fmt.Errorf("upstream returned %s", resp.Status)
+		_, _ = io.Copy(io.Discard, io.LimitReader(resp.Body, 1<<16))
+		_ = resp.Body.Close()
 	}
-	if rangeHeader != "" {
-		httpReq.Header.Set("Range", rangeHeader)
+	return nil, lastErr
+}
+
+const (
+	// mediaFetchAttempts 媒体拉取最多尝试次数（含首次）。
+	mediaFetchAttempts = 3
+	// mediaFetchRetryDelay 重试退避基数，实际等待为 (attempt-1) 倍。
+	mediaFetchRetryDelay = 400 * time.Millisecond
+)
+
+// mediaRetryableStatus 判断上游状态码是否值得重试。
+// 403/429 是图床并发限流的表现，5xx 是上游抖动。
+func mediaRetryableStatus(code int) bool {
+	switch code {
+	case http.StatusForbidden, http.StatusRequestTimeout, http.StatusTooManyRequests,
+		http.StatusInternalServerError, http.StatusBadGateway,
+		http.StatusServiceUnavailable, http.StatusGatewayTimeout:
+		return true
+	default:
+		return false
 	}
-	return s.http.Do(httpReq)
+}
+
+// sourceReferer 把书源的 origin 转成可用的默认 Referer。
+//
+// 只有 origin 本身是合法的 http(s) 地址时才使用；聚合类书源的 origin 是
+// 「显示名」，用它当 Referer 会被图床当成盗链（见 FetchMedia 中的注释），
+// 此时返回空串表示不发 Referer。
+func sourceReferer(origin string) string {
+	origin = strings.TrimSpace(origin)
+	if origin == "" {
+		return ""
+	}
+	u, err := url.Parse(origin)
+	if err != nil || u.Host == "" || (u.Scheme != "http" && u.Scheme != "https") {
+		return ""
+	}
+	return strings.TrimSuffix(origin, "/") + "/"
 }
 
 // RewritePlaylist 重写 m3u8 播放列表：分片与密钥地址改写为签名代理地址。
diff --git a/web/src/pages/reader/ReaderComic.tsx b/web/src/pages/reader/ReaderComic.tsx
index f91fd59..b686258 100644
--- a/web/src/pages/reader/ReaderComic.tsx
+++ b/web/src/pages/reader/ReaderComic.tsx
@@ -16,29 +16,57 @@ interface ReaderComicProps {
   onScrolled: () => void
 }
 
-function ComicImage({ src, theme }: { src: string; theme: { bg: string; text: string; accent: string } }) {
+function ComicImage({
+  src,
+  theme,
+  fit = false,
+}: {
+  src: string
+  theme: { bg: string; text: string; accent: string }
+  // fit：单页模式用。整页缩放至视口内，长图不再被 overflow-hidden 的容器裁掉。
+  fit?: boolean
+}) {
   const [state, setState] = useState<'loading' | 'ok' | 'error'>('loading')
+
+  // 换章后 src 变了要重新回到 loading：否则上一章加载失败的第 N 张会一直
+  // 显示「图片加载失败」，而 key 不变（滚动模式按序号做 key）不会重挂载。
+  useEffect(() => {
+    setState('loading')
+  }, [src])
+
+  // <img> 必须始终留在渲染树里（不能 display:none）：浏览器不会去拉取
+  // display:none 的 loading="lazy" 图片，onLoad 就永远不会触发，于是更没机会
+  // 脱离 loading —— 之前用 hidden 藏图就死在这里，漫画只剩一个转圈。
+  // 改成图片正常参与布局，未加载时用 minHeight 占位，转圈/失败信息盖在上层。
   return (
-    <div className="relative w-full">
+    <div
+      className={`relative flex w-full items-center justify-center ${fit ? 'h-full' : ''}`}
+      style={{ backgroundColor: theme.bg }}
+    >
+      <img
+        src={src}
+        loading="lazy"
+        alt=""
+        onLoad={() => setState('ok')}
+        onError={() => setState('error')}
+        className={fit ? 'block max-h-full w-auto max-w-full object-contain' : 'block w-full'}
+        style={state === 'ok' ? undefined : { minHeight: '10rem' }}
+      />
       {state === 'loading' && (
-        <div className="flex h-64 w-full items-center justify-center" style={{ color: theme.text }}>
+        <div
+          className="pointer-events-none absolute inset-0 flex items-center justify-center"
+          style={{ color: theme.text }}
+        >
           <Loader2 className="animate-spin opacity-50" size={22} />
         </div>
       )}
-      {state === 'error' ? (
-        <div className="flex h-40 w-full items-center justify-center text-xs opacity-50" style={{ color: theme.text }}>
+      {state === 'error' && (
+        <div
+          className="pointer-events-none absolute inset-0 flex items-center justify-center text-xs opacity-60"
+          style={{ color: theme.text }}
+        >
           图片加载失败
         </div>
-      ) : (
-        <img
-          src={src}
-          loading="lazy"
-          alt=""
-          onLoad={() => setState('ok')}
-          onError={() => setState('error')}
-          className={`block w-full ${state === 'loading' ? 'hidden' : ''}`}
-          style={{ backgroundColor: theme.bg }}
-        />
       )}
     </div>
   )
@@ -83,7 +111,7 @@ export function ReaderComic({ images, theme, mode, page, onZone, initialImage, o
     const idx = Math.min(Math.max(page, 0), images.length - 1)
     return (
       <div className="flex h-full items-center justify-center">
-        <ComicImage key={images[idx]} src={images[idx]} theme={theme} />
+        <ComicImage key={images[idx]} src={images[idx]} theme={theme} fit />
       </div>
     )
   }