commit remaining frontend updates

public/css/style.css

@@ -12,7 +12,7 @@ body {
 .page { display: none; }
 .page.active { display: flex; flex-direction: column; }
 
-#loginPage {
+#loginPage, #registerPage {
   min-height: 100vh;
   justify-content: center;
   align-items: center;
@@ -68,6 +68,12 @@ body {
   background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
   color: #fff;
 }
+.btn-secondary {
+  background: transparent;
+  color: #667eea;
+  border: 1px solid #667eea;
+  margin-top: 12px;
+}
 .login-error {
   color: #e74c3c;
   text-align: center;
@@ -76,6 +82,17 @@ body {
   min-height: 20px;
 }
 
+.login-register-link {
+  text-align: center;
+  margin-top: 16px;
+}
+
+.login-register-link a {
+  color: #667eea;
+  text-decoration: none;
+  font-size: 14px;
+}
+
 /* 首页 */
 #homePage {
   min-height: 100vh;