优化结果预览渲染体验

src/app/globals.css

@@ -264,6 +264,43 @@ h3 {
   white-space: pre-wrap;
 }
 
+.markdown-preview {
+  background: #f6f7f9;
+  border-radius: 6px;
+  display: grid;
+  gap: 0.75rem;
+  margin-top: 0.75rem;
+  padding: 0.85rem;
+}
+
+.markdown-block {
+  animation: markdown-block-in 0.36s ease both;
+}
+
+.markdown-heading {
+  color: #172033;
+  font-size: 1rem;
+  font-weight: 800;
+  line-height: 1.45;
+  margin-top: 0.2rem;
+}
+
+.markdown-paragraph {
+  color: #172033;
+  line-height: 1.75;
+  margin: 0;
+  white-space: pre-wrap;
+}
+
+.markdown-list {
+  color: #172033;
+  display: grid;
+  gap: 0.45rem;
+  line-height: 1.7;
+  margin: 0;
+  padding-left: 1.2rem;
+}
+
 .tag-row,
 .export-row {
   display: flex;
@@ -357,7 +394,7 @@ h3 {
   border-left-color: #20846d;
 }
 
-.streaming-preview pre {
+.streaming-preview .markdown-preview {
   animation: preview-breathe 1.8s ease-in-out infinite;
   background: #f4fbf8;
   border: 1px solid #d6eee8;
@@ -548,3 +585,15 @@ h3 {
     transform: translateY(0) scale(1);
   }
 }
+
+@keyframes markdown-block-in {
+  0% {
+    opacity: 0;
+    transform: translateY(0.35rem);
+  }
+
+  100% {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}