style(player): adjust subtitle text styling and container padding

- unify margin for OriginalTextLine and TranslatedTextLine components
- remove bilingual-specific margin in SubtitleContent
- remove padding from ContentContainer in SubtitleOverlay
- ensure consistent styling and spacing across components

Author: mkdir700

src/renderer/src/pages/player/components/SubtitleContent.tsx

@@ -524,21 +524,15 @@ const OriginalTextLine = styled.div<{ $fontSize?: string }>`
   font-size: ${(props) => props.$fontSize || '16px'};
   font-weight: 600;
   text-shadow: var(--subtitle-text-shadow);
-  margin-bottom: 0;
   transition: all var(--subtitle-transition-duration);
-
-  /* 在双语模式下添加间距 */
-  &.bilingual {
-    margin-bottom: 8px;
-  }
+  margin: 4px;
 `
 
 const TranslatedTextLine = styled.div<{ $fontSize?: string }>`
   font-size: ${(props) => props.$fontSize || '15px'};
   font-weight: 500;
   opacity: 0.95;
   text-shadow: var(--subtitle-text-shadow);
-  margin-top: 0;
   transition: all var(--subtitle-transition-duration);
 `
 

src/renderer/src/pages/player/components/SubtitleOverlay.tsx

@@ -1000,7 +1000,6 @@ const ContentContainer = styled.div<{
   display: flex;
   align-items: center;
   justify-content: center;
-  padding: 12px 16px;
   border-radius: 8px;
   box-sizing: border-box;
   position: relative;