feat(projects): 添加多页签风格：按钮和浏览器两种风格

src/styles/css/animation.css

@@ -0,0 +1,9 @@
+/* opacity透明过度 */
+.transition-opacity-enter-active,
+.transition-opacity-enter-active {
+  transition: opacity 0.4s ease-out;
+}
+.transition-opacity-enter-from,
+.transition-opacity-leave-to {
+  opacity: 0;
+}

src/styles/css/global.css

@@ -1,4 +1,5 @@
 @import './scrollbar.css';
+@import './animation.css';
 
 html,
 body,