🎨ui: 优化Identity样式

OpenAuth.Identity/Views/Home/Index.cshtml

@@ -1,21 +1,19 @@
-<div class="welcome-page">
-    <div class="row page-header">
-        <div class="col-sm-10">
-            <h1>
-                <img class="icon" src="~/icon.jpg">
-                Welcome to OpenAuth.Net IdentityServer
-                <small>(OpenIddict)</small>
-            </h1>
-        </div>
+<div class="auth-card auth-card--wide">
+    <div class="auth-card-header">
+        <div class="auth-icon">&#127968;</div>
+        <h1>OpenAuth.Net 认证中心</h1>
+        <p>基于 OpenIddict 的统一身份认证平台</p>
     </div>
 
-    <div class="row">
-        <div class="col-sm-8">
-            <p>
-                IdentityServer publishes a
-                <a href="~/.well-known/openid-configuration">discovery document</a>
-                where you can find metadata and links to all the endpoints, key material, etc.
-            </p>
+    <div class="welcome-content">
+        <div class="status-text">
+            本服务提供 OpenID Connect / OAuth 2.0 协议支持，为应用提供安全可靠的身份验证服务。
+        </div>
+
+        <div style="text-align: center; margin-top: 24px;">
+            <a class="discovery-link" href="~/.well-known/openid-configuration">
+                &#128279; 查看发现文档 (Discovery)
+            </a>
         </div>
     </div>
 </div>