feat: implement SourceBadgeList and SourceBadgeItem components for improved video source filtering

components/search/SourceBadgeItem.tsx

@@ -0,0 +1,73 @@
+/**
+ * SourceBadgeItem - Individual source badge component
+ * Displays a single video source badge with count, supports selection state
+ */
+
+interface SourceBadgeItemProps {
+  id: string;
+  name: string;
+  count: number;
+  isSelected: boolean;
+  onToggle: () => void;
+  isFocused?: boolean;
+  onFocus?: () => void;
+  innerRef?: (el: HTMLButtonElement | null) => void;
+}
+
+export function SourceBadgeItem({ 
+  id,
+  name, 
+  count, 
+  isSelected, 
+  onToggle, 
+  isFocused = false,
+  onFocus,
+  innerRef,
+}: SourceBadgeItemProps) {
+  const handleClick = () => {
+    // Immediate visual feedback before state update
+    onToggle();
+  };
+
+  return (
+    <button
+      ref={innerRef}
+      onClick={handleClick}
+      onFocus={onFocus}
+      onKeyDown={(e) => {
+        if (e.key === 'Enter' || e.key === ' ') {
+          e.preventDefault();
+          handleClick();
+        }
+      }}
+      tabIndex={0}
+      aria-pressed={isSelected}
+      aria-label={`${name} 视频源，${count} 个视频${isSelected ? '，已选中' : ''}`}
+      className={`
+        inline-flex items-center gap-1.5 px-4 py-2
+        rounded-full
+        border-2
+        text-sm font-medium whitespace-nowrap
+        transition-all duration-200 ease-out
+        hover:scale-105 hover:shadow-[var(--shadow-sm)]
+        active:scale-95 snap-start
+        focus:outline-none
+        ${isSelected 
+          ? 'bg-[var(--accent-color)] text-white border-[var(--accent-color)] shadow-md' 
+          : 'bg-[var(--glass-bg)] text-[var(--text-color)] border-[var(--glass-border)] hover:border-[var(--accent-color)]'
+        }
+      `}
+    >
+      <span>{name}</span>
+      <span className={`
+        px-2 py-0.5 rounded-full text-xs font-semibold
+        ${isSelected 
+          ? 'bg-white/20 text-white' 
+          : 'bg-[var(--accent-color)]/10 text-[var(--accent-color)]'
+        }
+      `}>
+        {count}
+      </span>
+    </button>
+  );
+}

components/search/SourceBadgeList.tsx

@@ -0,0 +1,123 @@
+/**
+ * SourceBadgeList - Badge list container with responsive layout
+ * Desktop: Expandable grid with show more/less
+ * Mobile: Horizontal scroll with snap
+ */
+
+'use client';
+
+import { useState, useRef, useCallback } from 'react';
+import { Icons } from '@/components/ui/Icon';
+import { SourceBadgeItem } from './SourceBadgeItem';
+import { useKeyboardNavigation } from '@/lib/hooks/useKeyboardNavigation';
+
+interface Source {
+  id: string;
+  name: string;
+  count: number;
+}
+
+interface SourceBadgeListProps {
+  sources: Source[];
+  selectedSources: Set<string>;
+  onToggleSource: (sourceId: string) => void;
+}
+
+export function SourceBadgeList({ sources, selectedSources, onToggleSource }: SourceBadgeListProps) {
+  const [isExpanded, setIsExpanded] = useState(false);
+  const [focusedIndex, setFocusedIndex] = useState(-1);
+  const containerRef = useRef<HTMLDivElement>(null);
+  const badgeRefs = useRef<(HTMLButtonElement | null)[]>([]);
+
+  // Keyboard navigation
+  useKeyboardNavigation({
+    enabled: true,
+    containerRef: containerRef,
+    currentIndex: focusedIndex,
+    itemCount: sources.length,
+    orientation: 'horizontal',
+    onNavigate: useCallback((index: number) => {
+      setFocusedIndex(index);
+      badgeRefs.current[index]?.focus();
+      // Scroll into view for mobile
+      badgeRefs.current[index]?.scrollIntoView({ 
+        behavior: 'smooth', 
+        block: 'nearest',
+        inline: 'center',
+      });
+    }, []),
+    onSelect: useCallback((index: number) => {
+      onToggleSource(sources[index].id);
+    }, [sources, onToggleSource]),
+  });
+
+  return (
+    <>
+      {/* Desktop: Expandable Grid */}
+      <div 
+        ref={containerRef}
+        className="hidden md:flex md:flex-col md:flex-1 -mx-1 px-1"
+        role="group"
+        aria-label="视频源筛选"
+      >
+        <div className={`flex items-center gap-2 flex-wrap transition-all duration-300 ${
+          !isExpanded ? 'max-h-[3rem] overflow-hidden' : ''
+        }`}>
+          {sources.map((source, index) => (
+            <SourceBadgeItem
+              key={source.id}
+              id={source.id}
+              name={source.name}
+              count={source.count}
+              isSelected={selectedSources.has(source.id)}
+              onToggle={() => onToggleSource(source.id)}
+              isFocused={focusedIndex === index}
+              onFocus={() => setFocusedIndex(index)}
+              innerRef={(el: HTMLButtonElement | null) => { badgeRefs.current[index] = el; }}
+            />
+          ))}
+        </div>
+        
+        {sources.length > 5 && (
+          <button
+            onClick={() => setIsExpanded(!isExpanded)}
+            className="mt-2 text-xs text-[var(--text-color-secondary)] hover:text-[var(--accent-color)] 
+                     flex items-center gap-1 transition-colors self-start"
+          >
+            <span>{isExpanded ? '收起' : '展开更多'}</span>
+            <Icons.ChevronDown 
+              size={14} 
+              className={`transition-transform duration-300 ${isExpanded ? 'rotate-180' : ''}`}
+            />
+          </button>
+        )}
+      </div>
+
+      {/* Mobile & Tablet: Horizontal Scroll */}
+      <div 
+        className="flex md:hidden flex-1 -mx-1 px-1 overflow-hidden"
+        role="group"
+        aria-label="视频源筛选"
+      >
+        <div 
+          ref={containerRef}
+          className="flex items-center gap-2 overflow-x-auto pb-2 scrollbar-hide snap-x snap-mandatory"
+        >
+          {sources.map((source, index) => (
+            <SourceBadgeItem
+              key={source.id}
+              id={source.id}
+              name={source.name}
+              count={source.count}
+              isSelected={selectedSources.has(source.id)}
+              onToggle={() => onToggleSource(source.id)}
+              isFocused={focusedIndex === index}
+              onFocus={() => setFocusedIndex(index)}
+              innerRef={(el: HTMLButtonElement | null) => { badgeRefs.current[index] = el; }}
+            />
+          ))}
+        </div>
+      </div>
+    </>
+  );
+}

components/search/SourceBadges.tsx

@@ -2,15 +2,15 @@
  * SourceBadges - Clickable video source badges with filtering
  * Shows available video sources with counts
  * Click to filter videos by source
- * Similar functionality to TypeBadges
+ * Responsive: Desktop shows expand/collapse, Mobile shows horizontal scroll
  */
 
 'use client';
 
 import { memo } from 'react';
 import { Card } from '@/components/ui/Card';
-import { Badge } from '@/components/ui/Badge';
 import { Icons } from '@/components/ui/Icon';
+import { SourceBadgeList } from './SourceBadgeList';
 
 interface Source {
   id: string;
@@ -52,43 +52,11 @@ export const SourceBadges = memo(function SourceBadges({
           </span>
         </div>
         
-        <div className="flex-1 flex items-center gap-2 flex-wrap">
-          {sources.map((source) => {
-            const isSelected = selectedSources.has(source.id);
-            
-            return (
-              <button
-                key={source.id}
-                onClick={() => onToggleSource(source.id)}
-                className={`
-                  inline-flex items-center gap-1.5 px-4 py-2
-                  rounded-full
-                  border-2
-                  text-sm font-medium whitespace-nowrap
-                  transition-all duration-200 ease-out
-                  hover:scale-105 hover:shadow-[var(--shadow-sm)]
-                  active:scale-95
-                  focus:outline-none
-                  ${isSelected 
-                    ? 'bg-[var(--accent-color)] text-white border-[var(--accent-color)] shadow-md' 
-                    : 'bg-[var(--glass-bg)] text-[var(--text-color)] border-[var(--glass-border)] hover:border-[var(--accent-color)]'
-                  }
-                `}
-              >
-                <span>{source.name}</span>
-                <span className={`
-                  px-2 py-0.5 rounded-full text-xs font-semibold
-                  ${isSelected 
-                    ? 'bg-white/20 text-white' 
-                    : 'bg-[var(--accent-color)]/10 text-[var(--accent-color)]'
-                  }
-                `}>
-                  {source.count}
-                </span>
-              </button>
-            );
-          })}
-        </div>
+        <SourceBadgeList
+          sources={sources}
+          selectedSources={selectedSources}
+          onToggleSource={onToggleSource}
+        />
       </div>
       
       {selectedSources.size > 0 && (

components/search/TypeBadgeList.tsx

@@ -93,13 +93,13 @@ export function TypeBadgeList({ badges, selectedTypes, onToggleType }: TypeBadge
 
       {/* Mobile & Tablet: Horizontal Scroll */}
       <div 
-        className="flex md:hidden flex-1 -mx-1 px-1"
+        className="flex md:hidden flex-1 -mx-1 px-1 overflow-hidden"
         role="group"
         aria-label="类型筛选"
       >
         <div 
           ref={containerRef}
-          className="flex items-center gap-2 overflow-x-auto overflow-y-visible pb-2 scrollbar-hide snap-x snap-mandatory"
+          className="flex items-center gap-2 overflow-x-auto pb-2 scrollbar-hide snap-x snap-mandatory"
         >
           {badges.map((badge, index) => (
             <TypeBadgeItem