fix(auth): 登录页靠上排列并支持外部失焦

lib/pages/auth/auth_view.dart

@@ -40,9 +40,9 @@ const double _buttonRadius = 25;
 const double _errorOpacity = 0.10;
 const double _errorBorderOpacity = 0.28;
 const double _enterSlideDistance = 16;
-const double _topContentPadding = 64;
+const double _topContentPadding = 56;
 const double _bottomContentPadding = 28;
-const double _compactTopContentPadding = 48;
+const double _compactTopContentPadding = 40;
 const double _compactHeightBreakpoint = 720;
 const double _compactBrandGap = 16;
 const double _glowSize = 280;
@@ -159,6 +159,19 @@ class _AuthPageState extends State<AuthPage> {
     }
   }
 
+  /// 点在当前邮箱或密码框之外时取消焦点。
+  void _releaseFieldFocus(PointerDownEvent event) {
+    final focus = FocusManager.instance.primaryFocus;
+    if (focus != _emailFocus && focus != _passwordFocus) return;
+    final renderObject = focus?.context?.findRenderObject();
+    if (renderObject is! RenderBox || !renderObject.hasSize) {
+      focus?.unfocus();
+      return;
+    }
+    final bounds = renderObject.localToGlobal(Offset.zero) & renderObject.size;
+    if (!bounds.contains(event.position)) focus?.unfocus();
+  }
+
   void _scheduleRevealFocusedField() {
     WidgetsBinding.instance.addPostFrameCallback((_) {
       if (mounted) _revealFocusedField();
@@ -325,26 +338,31 @@ class _AuthPageState extends State<AuthPage> {
                       effectiveKeyboardInset(context, _keyboardInset);
                   final available = constraints.maxHeight - top - bottom;
                   final minHeight = available > 0 ? available : 0.0;
-                  return AutofillGroup(
-                    child: SingleChildScrollView(
-                      key: const Key('auth-scroll'),
-                      controller: _scrollController,
-                      keyboardDismissBehavior:
-                          ScrollViewKeyboardDismissBehavior.onDrag,
-                      padding: EdgeInsets.fromLTRB(
-                        AppDimens.pageHorizontal,
-                        top,
-                        AppDimens.pageHorizontal,
-                        bottom,
-                      ),
-                      child: ConstrainedBox(
-                        constraints: BoxConstraints(minHeight: minHeight),
-                        child: Center(
-                          child: ConstrainedBox(
-                            constraints: const BoxConstraints(
-                              maxWidth: _contentMaxWidth,
+                  return Listener(
+                    behavior: HitTestBehavior.translucent,
+                    onPointerDown: _releaseFieldFocus,
+                    child: AutofillGroup(
+                      child: SingleChildScrollView(
+                        key: const Key('auth-scroll'),
+                        controller: _scrollController,
+                        keyboardDismissBehavior:
+                            ScrollViewKeyboardDismissBehavior.onDrag,
+                        padding: EdgeInsets.fromLTRB(
+                          AppDimens.pageHorizontal,
+                          top,
+                          AppDimens.pageHorizontal,
+                          bottom,
+                        ),
+                        child: ConstrainedBox(
+                          constraints: BoxConstraints(minHeight: minHeight),
+                          child: Align(
+                            alignment: Alignment.topCenter,
+                            child: ConstrainedBox(
+                              constraints: const BoxConstraints(
+                                maxWidth: _contentMaxWidth,
+                              ),
+                              child: _content(l10n, compact: compact),
                             ),
-                            child: _content(l10n, compact: compact),
                           ),
                         ),
                       ),
@@ -410,7 +428,7 @@ class _AuthPageState extends State<AuthPage> {
 
   Widget _landing(AppLocalizations l10n) => Column(
     key: const Key('auth-landing'),
-    mainAxisAlignment: MainAxisAlignment.center,
+    mainAxisAlignment: MainAxisAlignment.start,
     crossAxisAlignment: CrossAxisAlignment.stretch,
     children: [
       Center(