style(StudyCatalogPopup): 调整课程标题字体大小

@@ -14,7 +14,7 @@
                         <div v-if="lesson.progress > 0 && lesson.progress < 100"
                             class="absolute top-2 right-2 px-2 py-1 bg-green-100 text-green-600 text-xs rounded">
                             上次看到</div>
-                        <div class="text-black text-base mb-2"
+                        <div class="text-black text-sm mb-2"
                             :class="{ 'text-green-600 font-medium': String(courseId) === String(lesson.id) }">
                             {{ lesson.title }} •
                             <span class="text-sm text-gray-500">{{ courseTypeMaps[lesson.course_type] }}</span>