确认按钮改为 Liquid Glass 风格

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

LearnEnglish/LearnEnglish/Views/SpellingInputView.swift

@@ -60,17 +60,44 @@ final class SpellingInputView: UIView, UITextFieldDelegate {
         let accessory = UIView()
         accessory.frame = CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: 52)
         accessory.backgroundColor = .clear
-        let confirmButton = UIButton(type: .system)
-        confirmButton.setTitle("确认", for: .normal)
-        confirmButton.titleLabel?.font = .systemFont(ofSize: 17, weight: .semibold)
-        confirmButton.addAction(UIAction { [weak self] _ in
+
+        let glassButton = UIButton(type: .custom)
+        glassButton.layer.cornerRadius = 14
+        glassButton.layer.borderWidth = 0.5
+        glassButton.layer.borderColor = UIColor(white: 1, alpha: 0.6).cgColor
+        glassButton.clipsToBounds = true
+
+        let renderer = UIGraphicsImageRenderer(size: CGSize(width: 60, height: 44))
+        let bgImage = renderer.image { ctx in
+            let gradient = CGGradient(
+                colorsSpace: CGColorSpaceCreateDeviceRGB(),
+                colors: [UIColor(white: 1, alpha: 0.65).cgColor, UIColor(white: 1, alpha: 0.2).cgColor] as CFArray,
+                locations: [0, 0.5]
+            )!
+            ctx.cgContext.drawLinearGradient(gradient,
+                start: CGPoint(x: 0, y: 0), end: CGPoint(x: 0, y: 44), options: [])
+        }
+        glassButton.setBackgroundImage(bgImage, for: .normal)
+
+        var titleConfig = UIButton.Configuration.plain()
+        titleConfig.title = "确认"
+        titleConfig.baseForegroundColor = .white
+        titleConfig.titleTextAttributesTransformer = UIConfigurationTextAttributesTransformer { incoming in
+            var outgoing = incoming
+            outgoing.font = .systemFont(ofSize: 16, weight: .semibold)
+            return outgoing
+        }
+        glassButton.configuration = titleConfig
+        glassButton.addAction(UIAction { [weak self] _ in
             self?.onSubmit?()
         }, for: .touchUpInside)
-        confirmButton.translatesAutoresizingMaskIntoConstraints = false
-        accessory.addSubview(confirmButton)
+        glassButton.translatesAutoresizingMaskIntoConstraints = false
+        accessory.addSubview(glassButton)
         NSLayoutConstraint.activate([
-            confirmButton.trailingAnchor.constraint(equalTo: accessory.trailingAnchor, constant: -8),
-            confirmButton.topAnchor.constraint(equalTo: accessory.topAnchor, constant: 8)
+            glassButton.trailingAnchor.constraint(equalTo: accessory.trailingAnchor, constant: -15),
+            glassButton.centerYAnchor.constraint(equalTo: accessory.centerYAnchor),
+            glassButton.widthAnchor.constraint(equalToConstant: 60),
+            glassButton.heightAnchor.constraint(equalToConstant: 44)
         ])
         hiddenField.inputAccessoryView = accessory