style(css): 优化新闻页及案例卡片的样式表现

- 删除.case-card h3和.case-card-large h3中的font-size属性，统一字号
- 为.news-page-body添加flex布局和垂直方向排列
- 调整.news-page-body h3的高度和字体大小，添加多行文本截断样式
- 修改.news-page-summary的外边距和最小高度，添加多行文本截断样式
- 调整.news-page-meta的顶部间距和内边距，优化分隔线位置和整体布局

src/style.css

@@ -950,7 +950,6 @@ img {
 
 .case-card h3 {
     margin: 0;
-    font-size: 20px;
     line-height: 1.45;
     color: #2f3239;
     display: -webkit-box;
@@ -1206,6 +1205,8 @@ img {
 }
 
 .news-page-body {
+    display: flex;
+    flex-direction: column;
     padding: 22px 24px 24px;
 }
 
@@ -1217,10 +1218,14 @@ img {
 
 .news-page-body h3 {
     margin: 0;
-    min-height: 70px;
-    font-size: 24px;
+    min-height: calc(20px * 1.45 * 2);
+    font-size: 20px;
     line-height: 1.45;
     color: #373b42;
+    display: -webkit-box;
+    -webkit-box-orient: vertical;
+    -webkit-line-clamp: 2;
+    overflow: hidden;
     transition: color 0.2s ease;
 }
 
@@ -1229,11 +1234,15 @@ img {
 }
 
 .news-page-summary {
-    margin: 18px 0 22px;
-    min-height: 86px;
+    margin: 18px 0 0;
+    min-height: calc(15px * 1.9 * 3);
     font-size: 15px;
     line-height: 1.9;
     color: #737780;
+    display: -webkit-box;
+    -webkit-box-orient: vertical;
+    -webkit-line-clamp: 3;
+    overflow: hidden;
 }
 
 .news-page-meta {
@@ -1241,7 +1250,8 @@ img {
     align-items: center;
     justify-content: space-between;
     gap: 16px;
-    padding-top: 18px;
+    margin-top: 12px;
+    padding-top: 8px;
     border-top: 1px solid #edf0f3;
     font-size: 13px;
     color: #9b9fa7;
@@ -2279,7 +2289,6 @@ img {
 }
 
 .case-card-large h3 {
-    font-size: 22px;
 }
 
 .case-card-large .case-subtitle {
@@ -2944,7 +2953,6 @@ img {
 
     .case-card h3,
     .case-card-large h3 {
-        font-size: 20px;
     }
 
     .case-subtitle,