refactor: 优化 Markdown 编辑器高度与布局样式

src/lib/components/admin/MarkdownEditor.svelte

@@ -81,26 +81,25 @@
 			fontFamily: 'inherit',
 			fontSize: '1.05rem',
 			border: '1px solid rgba(0, 0, 0, 0.12)',
-			transition: 'border-color 0.3s ease, box-shadow 0.3s ease',
-			minHeight: '400px',
-			height: '100%'
+			transition: 'border-color 0.3s ease, box-shadow 0.3s ease'
 		},
 		'&.cm-focused': {
 			outline: 'none',
 			borderColor: 'var(--accent-color, #419b38)',
 			boxShadow: '0 0 0 3px rgba(65, 155, 56, 0.08)'
 		},
+		// 同时撑高正文和单列 gutter；.cm-gutters 的 min-height 由 CodeMirror 内联管理。
+		'.cm-content, .cm-gutter': {
+			minHeight: '400px'
+		},
 		'.cm-content': {
-			minHeight: '100%',
 			padding: '12px 14px',
 			lineHeight: '1.8'
 		},
 		'.cm-scroller': {
-			overflow: 'auto',
-			minHeight: '100%'
+			overflow: 'auto'
 		},
 		'.cm-gutters': {
-			minHeight: '100%',
 			backgroundColor: 'rgba(0, 0, 0, 0.03)',
 			color: 'rgba(0, 0, 0, 0.4)',
 			borderRight: '1px solid rgba(0, 0, 0, 0.12)',
@@ -377,18 +376,6 @@
 
 	.editor-container {
 		width: 100%;
-		min-height: 400px;
-		display: flex;
-		flex-direction: column;
-	}
-
-	.editor-container :global(.cm-editor) {
-		flex: 1;
-		height: 100%;
-	}
-
-	.editor-container :global(.cm-scroller) {
-		align-items: stretch !important;
 	}
 
 	.md-toolbar {