feat(auth): 优化登录页面移动端键盘适配与输入框样式

- 将页面容器的高度单位从 vh 改为 dvh 以适配移动端键盘弹出
- 分离登录页面容器样式，提高可维护性
- 调整输入框字体大小为 16px 防止 iOS 自动缩放

frontend/app/web-gold/src/views/auth/Login.vue

@@ -1,5 +1,5 @@
 <template>
-  <div class="min-h-screen bg-background relative overflow-hidden">
+  <div class="login-page bg-background relative">
     <!-- 动态背景层 -->
     <div class="absolute inset-0 overflow-hidden">
       <div class="gradient-orb orb-1"></div>
@@ -22,7 +22,7 @@
     </div>
 
     <!-- 主内容区 -->
-    <div class="min-h-screen flex flex-col lg:flex-row relative z-20">
+    <div class="login-content flex flex-col lg:flex-row relative z-20">
       <!-- 左侧品牌区 -->
       <div class="flex-1 flex items-center justify-center p-6 sm:p-10 lg:p-16 animate-fade-in">
         <div class="w-full max-w-md">
@@ -443,6 +443,19 @@ async function handleSmsLogin() {
 </script>
 
 <style scoped lang="less">
+// ========== 页面容器（dvh 适配移动端键盘）==========
+.login-page {
+  min-height: 100vh;
+  min-height: 100dvh;
+  overflow-x: hidden;
+  overflow-y: auto;
+}
+
+.login-content {
+  min-height: 100vh;
+  min-height: 100dvh;
+}
+
 // ========== 背景层 ==========
 .gradient-orb {
   position: absolute;
@@ -718,7 +731,7 @@ async function handleSmsLogin() {
   border: none;
   background: transparent;
   color: var(--foreground);
-  font-size: 15px;
+  font-size: 16px;
   outline: none;
 
   &::placeholder {