diff --git a/Sources/TUIKit/Core/Color.swift b/Sources/TUIKit/Core/Color.swift
index fba851b..d8d28bc 100644
--- a/Sources/TUIKit/Core/Color.swift
+++ b/Sources/TUIKit/Core/Color.swift
@@ -216,15 +216,7 @@ public struct Color: Sendable, Equatable {
     /// - Parameter amount: The amount to lighten (0-1, default 0.2).
     /// - Returns: A lighter color.
     public func lighter(by amount: Double = 0.2) -> Color {
-        guard case .rgb(let red, let green, let blue) = value else {
-            return self
-        }
-
-        let newRed = UInt8(min(255, Double(red) + 255 * amount))
-        let newGreen = UInt8(min(255, Double(green) + 255 * amount))
-        let newBlue = UInt8(min(255, Double(blue) + 255 * amount))
-
-        return .rgb(newRed, newGreen, newBlue)
+        adjusted(by: amount)
     }
 
     /// Returns a darker version of this color.
@@ -232,13 +224,24 @@ public struct Color: Sendable, Equatable {
     /// - Parameter amount: The amount to darken (0-1, default 0.2).
     /// - Returns: A darker color.
     public func darker(by amount: Double = 0.2) -> Color {
+        adjusted(by: -amount)
+    }
+
+    /// Adjusts brightness by a signed amount.
+    ///
+    /// Positive values lighten, negative values darken.
+    ///
+    /// - Parameter amount: The adjustment amount (-1 to 1).
+    /// - Returns: The adjusted color, or self if not an RGB color.
+    private func adjusted(by amount: Double) -> Color {
         guard case .rgb(let red, let green, let blue) = value else {
             return self
         }
 
-        let newRed = UInt8(max(0, Double(red) - 255 * amount))
-        let newGreen = UInt8(max(0, Double(green) - 255 * amount))
-        let newBlue = UInt8(max(0, Double(blue) - 255 * amount))
+        let shift = 255 * amount
+        let newRed = UInt8(min(255, max(0, Double(red) + shift)))
+        let newGreen = UInt8(min(255, max(0, Double(green) + shift)))
+        let newBlue = UInt8(min(255, max(0, Double(blue) + shift)))
 
         return .rgb(newRed, newGreen, newBlue)
     }
diff --git a/Sources/TUIKit/Core/Environment.swift b/Sources/TUIKit/Core/Environment.swift
index 2d4140c..b573186 100644
--- a/Sources/TUIKit/Core/Environment.swift
+++ b/Sources/TUIKit/Core/Environment.swift
@@ -202,24 +202,7 @@ extension EnvironmentModifier: Renderable {
 
         // Render content with modified environment
         return EnvironmentStorage.shared.withEnvironment(modifiedEnvironment) {
-            renderView(content, context: modifiedContext)
+            TUIKit.renderToBuffer(content, context: modifiedContext)
         }
     }
 }
-
-// MARK: - Internal Rendering Helper
-
-/// Internal helper to render a view (avoids name collision with Renderable.renderToBuffer).
-private func renderView<V: View>(_ view: V, context: RenderContext) -> FrameBuffer {
-    if let renderable = view as? Renderable {
-        return renderable.renderToBuffer(context: context)
-    }
-
-    if V.Body.self != Never.self {
-        return renderView(view.body, context: context)
-    }
-
-    return FrameBuffer()
-}
-
-
diff --git a/Sources/TUIKit/Core/Focus.swift b/Sources/TUIKit/Core/Focus.swift
index cfcea59..3bfe4dc 100644
--- a/Sources/TUIKit/Core/Focus.swift
+++ b/Sources/TUIKit/Core/Focus.swift
@@ -148,24 +148,23 @@ public final class FocusManager: @unchecked Sendable {
 
     /// Moves focus to the next focusable element.
     public func focusNext() {
-        guard !focusables.isEmpty else { return }
-
-        let availableFocusables = focusables.filter { $0.canBeFocused }
-        guard !availableFocusables.isEmpty else { return }
-
-        if let currentID = focusedID,
-           let currentIndex = availableFocusables.firstIndex(where: { $0.focusID == currentID }) {
-            // Move to next (wrap around)
-            let nextIndex = (currentIndex + 1) % availableFocusables.count
-            focus(availableFocusables[nextIndex])
-        } else {
-            // Focus first available
-            focus(availableFocusables[0])
-        }
+        moveFocus(direction: .forward)
     }
 
     /// Moves focus to the previous focusable element.
     public func focusPrevious() {
+        moveFocus(direction: .backward)
+    }
+
+    /// The direction in which focus moves.
+    private enum FocusDirection {
+        case forward, backward
+    }
+
+    /// Moves focus in the specified direction (wrapping around).
+    ///
+    /// - Parameter direction: The direction to move focus.
+    private func moveFocus(direction: FocusDirection) {
         guard !focusables.isEmpty else { return }
 
         let availableFocusables = focusables.filter { $0.canBeFocused }
@@ -173,12 +172,18 @@ public final class FocusManager: @unchecked Sendable {
 
         if let currentID = focusedID,
            let currentIndex = availableFocusables.firstIndex(where: { $0.focusID == currentID }) {
-            // Move to previous (wrap around)
-            let prevIndex = currentIndex == 0 ? availableFocusables.count - 1 : currentIndex - 1
-            focus(availableFocusables[prevIndex])
+            let targetIndex: Int
+            switch direction {
+            case .forward:
+                targetIndex = (currentIndex + 1) % availableFocusables.count
+            case .backward:
+                targetIndex = currentIndex == 0 ? availableFocusables.count - 1 : currentIndex - 1
+            }
+            focus(availableFocusables[targetIndex])
         } else {
-            // Focus last available
-            focus(availableFocusables[availableFocusables.count - 1])
+            // No current focus: forward → first, backward → last
+            let fallbackIndex = direction == .forward ? 0 : availableFocusables.count - 1
+            focus(availableFocusables[fallbackIndex])
         }
     }
 
diff --git a/Sources/TUIKit/Core/Theme.swift b/Sources/TUIKit/Core/Theme.swift
index 7ebb2c7..c6479fc 100644
--- a/Sources/TUIKit/Core/Theme.swift
+++ b/Sources/TUIKit/Core/Theme.swift
@@ -640,12 +640,16 @@ public struct GeneratedTheme: Theme, Sendable {
 
     /// Predefined hue values for common generated themes.
     public enum Hue {
+        /// Green hue (120°).
+        public static let green: Double = 120
         /// Violet hue (270°).
         public static let violet: Double = 270
     }
 
     // MARK: - Presets
 
+    /// A green generated theme — for direct comparison with GreenPhosphorTheme.
+    public static let green = GeneratedTheme(name: "Gen. Green", hue: Hue.green)
     /// A violet generated theme.
     public static let violet = GeneratedTheme(name: "Violet", hue: Hue.violet)
 }
@@ -656,9 +660,10 @@ public struct GeneratedTheme: Theme, Sendable {
 public struct ThemeRegistry {
     /// All available themes in cycling order.
     ///
-    /// Order: Green → Amber → White → Red → NCurses → Violet (generated)
+    /// Order: Green → Gen. Green → Amber → White → Red → NCurses → Violet (generated)
     public static let all: [Theme] = [
         GreenPhosphorTheme(),
+        GeneratedTheme.green,
         AmberPhosphorTheme(),
         WhitePhosphorTheme(),
         RedPhosphorTheme(),
diff --git a/Sources/TUIKit/Modifiers/BorderModifier.swift b/Sources/TUIKit/Modifiers/BorderModifier.swift
index d885b12..7dbbf99 100644
--- a/Sources/TUIKit/Modifiers/BorderModifier.swift
+++ b/Sources/TUIKit/Modifiers/BorderModifier.swift
@@ -34,7 +34,7 @@ extension BorderedView: Renderable {
         
         // Reduce available width for content by 2 (left + right border)
         var contentContext = context
-        contentContext.availableWidth = max(1, context.availableWidth - 2)
+        contentContext.availableWidth = max(1, context.availableWidth - BorderRenderer.borderWidthOverhead)
 
         // Render content with reduced width
         let buffer = TUIKit.renderToBuffer(content, context: contentContext)
diff --git a/Sources/TUIKit/Rendering/BorderRenderer.swift b/Sources/TUIKit/Rendering/BorderRenderer.swift
index 254d967..4d6c7c4 100644
--- a/Sources/TUIKit/Rendering/BorderRenderer.swift
+++ b/Sources/TUIKit/Rendering/BorderRenderer.swift
@@ -16,6 +16,9 @@
 /// - **Block**: half-block characters (▄ █ ▀) for smooth visual edges
 public enum BorderRenderer {
 
+    /// The total width consumed by left + right border characters (1 + 1 = 2).
+    public static let borderWidthOverhead = 2
+
     // MARK: - Standard Style (Box-Drawing Characters)
 
     /// Renders a plain top border line.
@@ -155,7 +158,7 @@ public enum BorderRenderer {
         innerWidth: Int,
         color: Color
     ) -> String {
-        let line = String(repeating: "▄", count: innerWidth + 2)
+        let line = String(repeating: BorderStyle.block.horizontal, count: innerWidth + 2)
         return ANSIRenderer.colorize(line, foreground: color)
     }
 
@@ -171,7 +174,7 @@ public enum BorderRenderer {
         innerWidth: Int,
         color: Color
     ) -> String {
-        let line = String(repeating: "▀", count: innerWidth + 2)
+        let line = String(repeating: BorderStyle.blockBottomHorizontal, count: innerWidth + 2)
         return ANSIRenderer.colorize(line, foreground: color)
     }
 
@@ -191,7 +194,7 @@ public enum BorderRenderer {
         sectionColor: Color
     ) -> String {
         let paddedLine = content.padToVisibleWidth(innerWidth)
-        let sideBorder = ANSIRenderer.colorize("█", foreground: sectionColor)
+        let sideBorder = ANSIRenderer.colorize(String(BorderStyle.block.vertical), foreground: sectionColor)
         let styledContent = ANSIRenderer.applyPersistentBackground(paddedLine, color: sectionColor)
         return sideBorder + styledContent + ANSIRenderer.reset + sideBorder
     }
@@ -203,13 +206,13 @@ public enum BorderRenderer {
     ///
     /// - Parameters:
     ///   - innerWidth: The content width (separator width = innerWidth + 2).
-    ///   - character: The separator character (`"▀"` for header→body, `"▄"` for body→footer).
+    ///   - character: The separator character (`.blockBottomHorizontal` for header→body, `.blockFooterSeparator` for body→footer).
     ///   - foregroundColor: The FG color (the section being transitioned from or to).
     ///   - backgroundColor: The BG color (the adjacent section).
     /// - Returns: The separator line.
     public static func blockSeparator(
         innerWidth: Int,
-        character: Character = "▀",
+        character: Character = BorderStyle.blockBottomHorizontal,
         foregroundColor: Color,
         backgroundColor: Color
     ) -> String {
diff --git a/Sources/TUIKit/TUIKit.swift b/Sources/TUIKit/TUIKit.swift
index cf8b886..a37bbf1 100644
--- a/Sources/TUIKit/TUIKit.swift
+++ b/Sources/TUIKit/TUIKit.swift
@@ -31,10 +31,13 @@ public let tuiKitVersion = "0.1.0"
 /// ```
 ///
 /// - Parameter content: A ViewBuilder closure that defines the view to render.
-@discardableResult
-public func renderOnce<Content: View>(@ViewBuilder content: () -> Content) -> Int {
+/// Renders a view hierarchy once and prints the result to standard output.
+///
+/// This is useful for simple CLI tools that don't need a full App lifecycle.
+///
+/// - Parameter content: A ViewBuilder closure that defines the view to render.
+public func renderOnce<Content: View>(@ViewBuilder content: () -> Content) {
     let view = content()
     let renderer = ViewRenderer()
     renderer.render(view)
-    return 0 // Line count not tracked by ViewRenderer
 }
diff --git a/Sources/TUIKit/Views/Alert.swift b/Sources/TUIKit/Views/Alert.swift
index b40cd4a..c61de8c 100644
--- a/Sources/TUIKit/Views/Alert.swift
+++ b/Sources/TUIKit/Views/Alert.swift
@@ -256,41 +256,21 @@ extension Alert {
 extension Alert where Actions == EmptyView {
     /// Creates a warning-style alert without actions.
     public static func warning(title: String = "Warning", message: String) -> Alert<EmptyView> {
-        Alert<EmptyView>(
-            title: title,
-            message: message,
-            borderColor: .yellow,
-            titleColor: .yellow
-        )
+        Alert.warning(title: title, message: message) { EmptyView() }
     }
 
     /// Creates an error-style alert without actions.
     public static func error(title: String = "Error", message: String) -> Alert<EmptyView> {
-        Alert<EmptyView>(
-            title: title,
-            message: message,
-            borderColor: .red,
-            titleColor: .red
-        )
+        Alert.error(title: title, message: message) { EmptyView() }
     }
 
     /// Creates an info-style alert without actions.
     public static func info(title: String = "Info", message: String) -> Alert<EmptyView> {
-        Alert<EmptyView>(
-            title: title,
-            message: message,
-            borderColor: .cyan,
-            titleColor: .cyan
-        )
+        Alert.info(title: title, message: message) { EmptyView() }
     }
 
     /// Creates a success-style alert without actions.
     public static func success(title: String = "Success", message: String) -> Alert<EmptyView> {
-        Alert<EmptyView>(
-            title: title,
-            message: message,
-            borderColor: .green,
-            titleColor: .green
-        )
+        Alert.success(title: title, message: message) { EmptyView() }
     }
 }
diff --git a/Sources/TUIKit/Views/ContainerView.swift b/Sources/TUIKit/Views/ContainerView.swift
index 9bfa70e..782af00 100644
--- a/Sources/TUIKit/Views/ContainerView.swift
+++ b/Sources/TUIKit/Views/ContainerView.swift
@@ -330,7 +330,7 @@ extension ContainerView: Renderable {
         if let footerBuf = footerBuffer, !footerBuf.isEmpty {
             if style.showFooterSeparator {
                 lines.append(BorderRenderer.blockSeparator(
-                    innerWidth: innerWidth, character: "▄",
+                    innerWidth: innerWidth, character: BorderStyle.blockFooterSeparator,
                     foregroundColor: headerFooterBg, backgroundColor: bodyBg
                 ))
             }
diff --git a/Sources/TUIKit/Views/StatusBar.swift b/Sources/TUIKit/Views/StatusBar.swift
index 8d6d5b5..9b6807d 100644
--- a/Sources/TUIKit/Views/StatusBar.swift
+++ b/Sources/TUIKit/Views/StatusBar.swift
@@ -896,7 +896,7 @@ extension StatusBar: Renderable {
 
     /// Renders the bordered style using the current appearance's border style.
     private func renderBordered(itemStrings: [String], width: Int, context: RenderContext) -> FrameBuffer {
-        let innerWidth = width - 2  // Account for left and right border
+        let innerWidth = width - BorderRenderer.borderWidthOverhead
         let content = alignContent(itemStrings: itemStrings, width: innerWidth)
 
         // Check if we're using block appearance for special rendering