diff --git a/rust_indicator/Cargo.toml b/rust_indicator/Cargo.toml
index c51dd8c..ecb7ba4 100644
--- a/rust_indicator/Cargo.toml
+++ b/rust_indicator/Cargo.toml
@@ -8,6 +8,7 @@ windows = { version = "0.58", features = [
     "Win32_Foundation",
     "Win32_UI_WindowsAndMessaging",
     "Win32_UI_Input_Ime",
+    "Win32_UI_Input_KeyboardAndMouse",
     "Win32_UI_Accessibility",
     "Win32_Graphics_Gdi",
     "Win32_Graphics_GdiPlus",
diff --git a/rust_indicator/src/config.rs b/rust_indicator/src/config.rs
index 5955b96..2f5f309 100644
--- a/rust_indicator/src/config.rs
+++ b/rust_indicator/src/config.rs
@@ -15,10 +15,12 @@ pub struct Config {
     pub poll_track_interval_ms: u64,
 
     pub tray_enable: bool,
+    pub debug_console: bool,
 
     pub caret_enable: bool,
     pub caret_color_cn: u32,
     pub caret_color_en: u32,
+    pub caret_color_en_upper: u32,
     pub caret_size: i32,
     pub caret_offset_x: i32,
     pub caret_offset_y: i32,
@@ -27,6 +29,7 @@ pub struct Config {
     pub mouse_enable: bool,
     pub mouse_color_cn: u32,
     pub mouse_color_en: u32,
+    pub mouse_color_en_upper: u32,
     pub mouse_size: i32,
     pub mouse_offset_x: i32,
     pub mouse_offset_y: i32,
@@ -40,16 +43,19 @@ impl Default for Config {
             poll_state_interval_ms: 100,
             poll_track_interval_ms: 10,
             tray_enable: true,
+            debug_console: false,
             caret_enable: true,
-            caret_color_cn: parse_color("#FF7800A0"),
-            caret_color_en: parse_color("#0078FF30"),
+            caret_color_cn: parse_color("#FF0000A0"),
+            caret_color_en: parse_color("#0000FFA0"),
+            caret_color_en_upper: parse_color("#008000A0"),
             caret_size: 8,
             caret_offset_x: 0,
             caret_offset_y: 0,
             caret_show_en: true,
             mouse_enable: true,
-            mouse_color_cn: parse_color("#FF7800A0"),
-            mouse_color_en: parse_color("#0078FF30"),
+            mouse_color_cn: parse_color("#FF0000A0"),
+            mouse_color_en: parse_color("#0000FFA0"),
+            mouse_color_en_upper: parse_color("#008000A0"),
             mouse_size: 8,
             mouse_offset_x: 2,
             mouse_offset_y: 18,
@@ -121,13 +127,20 @@ fn load_config() -> Config {
         if let Some(v) = get("poll",  "state_interval_ms") { if let Ok(n) = v.parse() { config.poll_state_interval_ms = n; } }
         if let Some(v) = get("poll",  "track_interval_ms") { if let Ok(n) = v.parse() { config.poll_track_interval_ms = n; } }
         
-        if let Some(v) = get("tray", "enable") { 
+        if let Some(v) = get("tray", "enable") {
             match v.as_str() {
                 "true" => config.tray_enable = true,
                 "false" => config.tray_enable = false,
                 _ => {} // 保持默认值
             }
         }
+        if let Some(v) = get("tray", "debug_console") {
+            match v.as_str() {
+                "true" => config.debug_console = true,
+                "false" => config.debug_console = false,
+                _ => {}
+            }
+        }
         
         if let Some(v) = get("caret", "enable") { 
             match v.as_str() {
@@ -138,6 +151,7 @@ fn load_config() -> Config {
         }
         if let Some(v) = get("caret", "color_cn") { config.caret_color_cn = v.parse_color(); }
         if let Some(v) = get("caret", "color_en") { config.caret_color_en = v.parse_color(); }
+        if let Some(v) = get("caret", "color_en_upper") { config.caret_color_en_upper = v.parse_color(); }
         if let Some(v) = get("caret", "size")     { if let Ok(n) = v.parse() { config.caret_size = n; } }
         if let Some(v) = get("caret", "offset_x") { if let Ok(n) = v.parse() { config.caret_offset_x = n; } }
         if let Some(v) = get("caret", "offset_y") { if let Ok(n) = v.parse() { config.caret_offset_y = n; } }
@@ -158,6 +172,7 @@ fn load_config() -> Config {
         }
         if let Some(v) = get("mouse", "color_cn") { config.mouse_color_cn = v.parse_color(); }
         if let Some(v) = get("mouse", "color_en") { config.mouse_color_en = v.parse_color(); }
+        if let Some(v) = get("mouse", "color_en_upper") { config.mouse_color_en_upper = v.parse_color(); }
         if let Some(v) = get("mouse", "size")     { if let Ok(n) = v.parse() { config.mouse_size = n; } }
         if let Some(v) = get("mouse", "offset_x") { if let Ok(n) = v.parse() { config.mouse_offset_x = n; } }
         if let Some(v) = get("mouse", "offset_y") { if let Ok(n) = v.parse() { config.mouse_offset_y = n; } }
@@ -188,11 +203,15 @@ track_interval_ms = 10    # 位置追踪间隔 (ms)
 
 [tray]
 enable = true               # 是否显示托盘图标 (false 时完全后台运行，只能通过任务管理器结束)
+debug_console = false       # 是否显示调试控制台 (用于开发调试)
 
 [caret]
+# 颜色格式：#RRGGBBAA
+# RR=红, GG=绿, BB=蓝, AA=透明度(00=透明, FF=不透明, A0=63%不透明)
 enable = true               # 是否启用文本光标提示
-color_cn = "#FF7800A0"    # 中文状态颜色 (#RRGGBBAA)
-color_en = "#0078FF30"    # 英文状态颜色
+color_cn = "#FF0000A0"    # 中文状态颜色（红）
+color_en = "#0000FFA0"    # 英文小写状态颜色（蓝）
+color_en_upper = "#008000A0"  # 英文大写状态颜色（绿）
 size = 8                    # 提示球大小
 offset_x = 0
 offset_y = 0
@@ -200,8 +219,9 @@ show_en = true              # 英文状态下是否显示
 
 [mouse]
 enable = true               # 是否开启鼠标提示
-color_cn = "#FF7800A0"    # 中文状态颜色
-color_en = "#0078FF30"    # 英文状态颜色
+color_cn = "#FF0000A0"    # 中文状态颜色（红）
+color_en = "#0000FFA0"    # 英文小写状态颜色（蓝）
+color_en_upper = "#008000A0"  # 英文大写状态颜色（绿）
 size = 8                    # 提示球大小
 offset_x = 2
 offset_y = 18
@@ -220,9 +240,11 @@ pub fn get() -> &'static Config { CONFIG.get_or_init(load_config) }
 pub fn state_poll_interval_ms() -> u64 { get().poll_state_interval_ms }
 pub fn track_poll_interval_ms() -> u64 { get().poll_track_interval_ms }
 pub fn tray_enable() -> bool { get().tray_enable }
+pub fn debug_console() -> bool { get().debug_console }
 pub fn caret_enable() -> bool { get().caret_enable }
 pub fn caret_color_cn() -> u32 { get().caret_color_cn }
 pub fn caret_color_en() -> u32 { get().caret_color_en }
+pub fn caret_color_en_upper() -> u32 { get().caret_color_en_upper }
 pub fn caret_size() -> i32 { get().caret_size }
 pub fn caret_offset_x() -> i32 { get().caret_offset_x }
 pub fn caret_offset_y() -> i32 { get().caret_offset_y }
@@ -230,6 +252,7 @@ pub fn caret_show_en() -> bool { get().caret_show_en }
 pub fn mouse_enable() -> bool { get().mouse_enable }
 pub fn mouse_color_cn() -> u32 { get().mouse_color_cn }
 pub fn mouse_color_en() -> u32 { get().mouse_color_en }
+pub fn mouse_color_en_upper() -> u32 { get().mouse_color_en_upper }
 pub fn mouse_size() -> i32 { get().mouse_size }
 pub fn mouse_offset_x() -> i32 { get().mouse_offset_x }
 pub fn mouse_offset_y() -> i32 { get().mouse_offset_y }
diff --git a/rust_indicator/src/fullscreen_detector.rs b/rust_indicator/src/fullscreen_detector.rs
new file mode 100644
index 0000000..6bfd82a
--- /dev/null
+++ b/rust_indicator/src/fullscreen_detector.rs
@@ -0,0 +1,80 @@
+//! 全屏应用检测模块
+//!
+//! 用于检测是否有应用程序处于全屏状态（如视频播放、游戏等），
+//! 在全屏时自动隐藏 IME 指示器，避免遮挡视频内容。
+
+use windows::Win32::Foundation::RECT;
+use windows::Win32::UI::WindowsAndMessaging::{
+    GetForegroundWindow, GetSystemMetrics, GetWindowRect, SM_CXSCREEN, SM_CYSCREEN,
+};
+
+/// 检测是否有应用程序处于全屏状态
+///
+/// 判断逻辑：
+/// 1. 获取当前活动窗口
+/// 2. 检查窗口是否覆盖整个屏幕
+/// 3. 排除桌面窗口（Progman）
+///
+/// # Returns
+/// - `true` - 检测到全屏应用
+/// - `false` - 无全屏应用
+pub fn is_fullscreen_app() -> bool {
+    unsafe {
+        // 获取当前活动窗口
+        let hwnd = GetForegroundWindow();
+
+        if hwnd.is_invalid() {
+            return false;
+        }
+
+        // 获取窗口矩形
+        let mut rect = RECT::default();
+        if GetWindowRect(hwnd, &mut rect).is_err() {
+            return false;
+        }
+
+        // 获取屏幕尺寸
+        let screen_width = GetSystemMetrics(SM_CXSCREEN);
+        let screen_height = GetSystemMetrics(SM_CYSCREEN);
+
+        // 检查窗口是否覆盖整个屏幕
+        // 允许小幅偏差（某些播放器可能会有几像素的边框）
+        let tolerance = 2;
+        let covers_screen = (rect.left <= tolerance)
+            && (rect.top <= tolerance)
+            && (rect.right >= screen_width - tolerance)
+            && (rect.bottom >= screen_height - tolerance);
+
+        if !covers_screen {
+            return false;
+        }
+
+        // 排除桌面窗口
+        // 获取窗口类名来判断是否是桌面
+        let mut class_name = [0u16; 256];
+        let _ = windows::Win32::UI::WindowsAndMessaging::GetClassNameW(hwnd, &mut class_name);
+
+        let class_name_str = String::from_utf16_lossy(
+            &class_name[..class_name.iter().position(|&c| c == 0).unwrap_or(0)],
+        );
+
+        // 排除桌面和某些系统窗口
+        if class_name_str.contains("Progman") || class_name_str.contains("WorkerW") {
+            return false;
+        }
+
+        true
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_fullscreen_detection() {
+        // 基本的功能测试
+        let result = is_fullscreen_app();
+        println!("Fullscreen status: {}", result);
+    }
+}
diff --git a/rust_indicator/src/ime_detector.rs b/rust_indicator/src/ime_detector.rs
index 3db231e..3cfcab7 100644
--- a/rust_indicator/src/ime_detector.rs
+++ b/rust_indicator/src/ime_detector.rs
@@ -2,10 +2,13 @@
 
 use windows::Win32::Foundation::HWND;
 use windows::Win32::UI::Input::Ime::ImmGetDefaultIMEWnd;
+use windows::Win32::UI::Input::KeyboardAndMouse::{GetKeyState, GetKeyboardLayout};
 use windows::Win32::UI::WindowsAndMessaging::{
     GetForegroundWindow, GetGUIThreadInfo, GetWindowThreadProcessId,
     SendMessageTimeoutW, GUITHREADINFO, SMTO_ABORTIFHUNG,
 };
+use windows::Win32::System::Console::{AllocConsole, SetConsoleTitleW};
+use windows::core::w;
 
 /// IME 控制消息
 const WM_IME_CONTROL: u32 = 0x283;
@@ -13,6 +16,76 @@ const IMC_GETOPENSTATUS: usize = 0x5;
 const IMC_GETCONVERSIONMODE: usize = 0x1;
 const IME_CMODE_NATIVE: u32 = 0x0001;
 
+/// 键盘布局 ID 常量
+const LAYOUT_ZH_CN: u32 = 0x0804;  // 中文 (中国)
+const LAYOUT_ZH_TW: u32 = 0x0404;  // 中文 (台湾)
+
+/// 调试状态结构体
+#[derive(Clone, PartialEq)]
+struct DebugState {
+    ime_hwnd: isize,
+    open_status: usize,
+    conversion_mode: usize,
+    has_native: bool,
+    layout_id: u32,
+    caps_lock: bool,
+}
+
+impl Default for DebugState {
+    fn default() -> Self {
+        Self {
+            ime_hwnd: 0,
+            open_status: 0,
+            conversion_mode: 0,
+            has_native: false,
+            layout_id: 0,
+            caps_lock: false,
+        }
+    }
+}
+
+/// 全局调试状态
+static mut LAST_STATE: Option<DebugState> = None;
+static mut DEBUG_LINE_NUM: u32 = 0;
+static mut CONSOLE_INITIALIZED: bool = false;
+
+/// 初始化调试控制台
+fn init_debug_console() {
+    unsafe {
+        if !CONSOLE_INITIALIZED && crate::config::debug_console() {
+            let _ = AllocConsole();
+            let _ = SetConsoleTitleW(w!("IME Indicator Debug Console"));
+            CONSOLE_INITIALIZED = true;
+        }
+    }
+}
+
+/// 打印调试状态
+fn print_debug_state(state: &DebugState, result: bool) {
+    unsafe {
+        DEBUG_LINE_NUM += 1;
+
+        let layout_str = match state.layout_id {
+            0x0409 => "0x0409(EN)",
+            0x0804 => "0x0804(ZH)",
+            0x0404 => "0x0404(TW)",
+            _ => &format!("0x{:04x}(?)", state.layout_id)[..],
+        };
+
+        println!(
+            "[{:03}] hwnd:{:#010x} open:{} conv:{} NATIVE:{} layout:{} caps:{} => {}",
+            DEBUG_LINE_NUM,
+            state.ime_hwnd,
+            state.open_status,
+            state.conversion_mode,
+            state.has_native,
+            layout_str,
+            state.caps_lock,
+            if result { "CN" } else { "EN" }
+        );
+    }
+}
+
 /// 获取当前焦点窗口
 fn get_focused_window() -> HWND {
     unsafe {
@@ -40,6 +113,16 @@ fn get_focused_window() -> HWND {
     }
 }
 
+/// 获取键盘布局 ID
+fn get_keyboard_layout_id() -> u32 {
+    unsafe {
+        let hwnd = get_focused_window();
+        let thread_id = GetWindowThreadProcessId(hwnd, None);
+        let hkl = GetKeyboardLayout(thread_id);
+        (hkl.0 as usize & 0xFFFF) as u32
+    }
+}
+
 /// 获取 IME 默认窗口句柄
 fn get_ime_window(hwnd: HWND) -> HWND {
     unsafe { ImmGetDefaultIMEWnd(hwnd) }
@@ -68,23 +151,68 @@ fn send_message_timeout(hwnd: HWND, msg: u32, wparam: usize, lparam: isize) -> O
 
 /// 检测是否为中文输入模式
 pub fn is_chinese_mode() -> bool {
+    init_debug_console();
+
     let hwnd = get_focused_window();
     let ime_hwnd = get_ime_window(hwnd);
-    
-    if ime_hwnd.0.is_null() {
-        return false;
-    }
 
-    // 获取 IME 开启状态
-    let open_status = send_message_timeout(ime_hwnd, WM_IME_CONTROL, IMC_GETOPENSTATUS, 0);
-    if open_status.unwrap_or(0) == 0 {
-        return false;
+    // 收集调试状态
+    let caps_lock = unsafe { (GetKeyState(0x14) & 0x0001) != 0 };
+    let mut state = DebugState {
+        ime_hwnd: ime_hwnd.0 as isize,
+        caps_lock,
+        ..Default::default()
+    };
+
+    let mut has_native = false;
+    let mut open_status = 0;
+
+    // 检查 IME 状态
+    if !ime_hwnd.0.is_null() {
+        if let Some(conversion_mode) = send_message_timeout(ime_hwnd, WM_IME_CONTROL, IMC_GETCONVERSIONMODE, 0) {
+            state.conversion_mode = conversion_mode;
+            has_native = (conversion_mode as u32 & IME_CMODE_NATIVE) != 0;
+            state.has_native = has_native;
+        }
+
+        if let Some(open) = send_message_timeout(ime_hwnd, WM_IME_CONTROL, IMC_GETOPENSTATUS, 0) {
+            open_status = open;
+            state.open_status = open;
+        }
     }
 
-    // 获取转换模式并检测是否包含 NATIVE 标志 (中文)
-    if let Some(conversion_mode) = send_message_timeout(ime_hwnd, WM_IME_CONTROL, IMC_GETCONVERSIONMODE, 0) {
-        return (conversion_mode as u32 & IME_CMODE_NATIVE) != 0;
+    let layout_id = get_keyboard_layout_id();
+    state.layout_id = layout_id;
+
+    // 检测逻辑
+    let result = if has_native {
+        layout_id == LAYOUT_ZH_CN || layout_id == LAYOUT_ZH_TW
+    } else if open_status == 1 {
+        layout_id == LAYOUT_ZH_CN || layout_id == LAYOUT_ZH_TW
+    } else {
+        false
+    };
+
+    // 调试输出
+    unsafe {
+        let should_print = match &LAST_STATE {
+            None => true,
+            Some(last) => state != *last,
+        };
+
+        if should_print {
+            print_debug_state(&state, result);
+            LAST_STATE = Some(state.clone());
+        }
     }
 
-    false
+    result
+}
+
+/// 检测 Caps Lock 是否开启
+pub fn is_caps_lock_on() -> bool {
+    unsafe {
+        let state = GetKeyState(0x14);
+        (state & 0x0001) != 0
+    }
 }
diff --git a/rust_indicator/src/main.rs b/rust_indicator/src/main.rs
index 7c7849f..a3c6c21 100644
--- a/rust_indicator/src/main.rs
+++ b/rust_indicator/src/main.rs
@@ -3,6 +3,7 @@
 mod caret_detector;
 mod config;
 mod cursor_detector;
+mod fullscreen_detector;
 mod ime_detector;
 mod overlay;
 mod tray;
@@ -16,7 +17,8 @@ use windows::Win32::UI::WindowsAndMessaging::{GetCursorPos, LoadIconW, IDI_APPLI
 
 use caret_detector::CaretDetector;
 use cursor_detector::CursorDetector;
-use ime_detector::is_chinese_mode;
+use fullscreen_detector::is_fullscreen_app;
+use ime_detector::{is_caps_lock_on, is_chinese_mode};
 use overlay::IndicatorOverlay;
 use tray::TrayManager;
 
@@ -104,6 +106,7 @@ fn run_detector_loop(running: Arc<AtomicBool>) {
             config::caret_size(),
             config::caret_color_cn(),
             config::caret_color_en(),
+            config::caret_color_en_upper(),
             config::caret_offset_x(),
             config::caret_offset_y(),
         ))
@@ -117,6 +120,7 @@ fn run_detector_loop(running: Arc<AtomicBool>) {
             config::mouse_size(),
             config::mouse_color_cn(),
             config::mouse_color_en(),
+            config::mouse_color_en_upper(),
             config::mouse_offset_x(),
             config::mouse_offset_y(),
         ))
@@ -129,8 +133,10 @@ fn run_detector_loop(running: Arc<AtomicBool>) {
 
     let mut last_state_check_time = Instant::now();
     let mut chinese_mode = false;
+    let mut caps_lock_on = false;
     let mut caret_active = false;
     let mut mouse_active = false;
+    let mut is_fullscreen = false;
 
     // 主线程负责消息循环，子线程负责检测
     while running.load(Ordering::SeqCst) {
@@ -138,21 +144,34 @@ fn run_detector_loop(running: Arc<AtomicBool>) {
 
         // A. 状态检测 (100ms)
         if now.duration_since(last_state_check_time) >= state_interval {
+            // 检测全屏状态
+            is_fullscreen = is_fullscreen_app();
+
             chinese_mode = is_chinese_mode();
+            caps_lock_on = is_caps_lock_on();
 
             // Caret 状态判断
             if config::caret_enable() {
                 if let Some(ref overlay) = caret_overlay {
-                    let caret_pos = caret_detector.get_caret_pos();
-                    
-                    let should_caret = caret_pos.is_some() && (chinese_mode || config::caret_show_en());
-                    if should_caret != caret_active {
-                        caret_active = should_caret;
+                    // 全屏时强制隐藏
+                    if is_fullscreen {
                         if caret_active {
-                            overlay.show();
-                        } else {
+                            caret_active = false;
                             overlay.hide();
                         }
+                    } else {
+                        // 非全屏时正常检测
+                        let caret_pos = caret_detector.get_caret_pos();
+
+                        let should_caret = caret_pos.is_some() && (chinese_mode || config::caret_show_en());
+                        if should_caret != caret_active {
+                            caret_active = should_caret;
+                            if caret_active {
+                                overlay.show();
+                            } else {
+                                overlay.hide();
+                            }
+                        }
                     }
                 }
             }
@@ -160,15 +179,24 @@ fn run_detector_loop(running: Arc<AtomicBool>) {
             // Mouse 状态判断
             if config::mouse_enable() {
                 if let Some(ref overlay) = mouse_overlay {
-                    let target_cursor = cursor_detector.is_target_cursor();
-                    let should_mouse = target_cursor && (chinese_mode || config::mouse_show_en());
-                    if should_mouse != mouse_active {
-                        mouse_active = should_mouse;
+                    // 全屏时强制隐藏
+                    if is_fullscreen {
                         if mouse_active {
-                            overlay.show();
-                        } else {
+                            mouse_active = false;
                             overlay.hide();
                         }
+                    } else {
+                        // 非全屏时正常检测
+                        let target_cursor = cursor_detector.is_target_cursor();
+                        let should_mouse = target_cursor && (chinese_mode || config::mouse_show_en());
+                        if should_mouse != mouse_active {
+                            mouse_active = should_mouse;
+                            if mouse_active {
+                                overlay.show();
+                            } else {
+                                overlay.hide();
+                            }
+                        }
                     }
                 }
             }
@@ -177,23 +205,25 @@ fn run_detector_loop(running: Arc<AtomicBool>) {
         }
 
         // B. 坐标追踪
-
-        // 1. 追踪文本光标
-        if config::caret_enable() && caret_active {
-            if let Some(ref overlay) = caret_overlay {
-                if let Some((x, y, h)) = caret_detector.get_caret_pos() {
-                    overlay.update(x, y, chinese_mode, h);
+        // 全屏时不追踪位置
+        if !is_fullscreen {
+            // 1. 追踪文本光标
+            if config::caret_enable() && caret_active {
+                if let Some(ref overlay) = caret_overlay {
+                    if let Some((x, y, h)) = caret_detector.get_caret_pos() {
+                        overlay.update(x, y, chinese_mode, caps_lock_on, h);
+                    }
                 }
             }
-        }
 
-        // 2. 追踪鼠标
-        if config::mouse_enable() && mouse_active {
-            if let Some(ref overlay) = mouse_overlay {
-                let mut pt = POINT::default();
-                unsafe {
-                    if GetCursorPos(&mut pt).is_ok() {
-                        overlay.update(pt.x, pt.y, chinese_mode, 0);
+            // 2. 追踪鼠标
+            if config::mouse_enable() && mouse_active {
+                if let Some(ref overlay) = mouse_overlay {
+                    let mut pt = POINT::default();
+                    unsafe {
+                        if GetCursorPos(&mut pt).is_ok() {
+                            overlay.update(pt.x, pt.y, chinese_mode, caps_lock_on, 0);
+                        }
                     }
                 }
             }
diff --git a/rust_indicator/src/overlay.rs b/rust_indicator/src/overlay.rs
index 49eab74..6d56b26 100644
--- a/rust_indicator/src/overlay.rs
+++ b/rust_indicator/src/overlay.rs
@@ -39,6 +39,7 @@ pub struct IndicatorOverlay {
     size: i32,
     color_cn: u32,
     color_en: u32,
+    color_en_upper: u32,
     offset_x: i32,
     offset_y: i32,
     gdi_token: usize,
@@ -51,6 +52,7 @@ impl IndicatorOverlay {
         size: i32,
         color_cn: u32,
         color_en: u32,
+        color_en_upper: u32,
         offset_x: i32,
         offset_y: i32,
     ) -> Self {
@@ -62,6 +64,7 @@ impl IndicatorOverlay {
             size,
             color_cn,
             color_en,
+            color_en_upper,
             offset_x,
             offset_y,
             gdi_token,
@@ -140,10 +143,17 @@ impl IndicatorOverlay {
     }
 
     /// 更新渲染内容和屏幕位置
-    pub fn update(&self, x: i32, y: i32, is_chinese: bool, caret_h: i32) {
-        let color = if is_chinese {
+    /// is_chinese: 是否中文模式
+    /// is_upper: 是否大写锁定（Caps Lock 开启）
+    pub fn update(&self, x: i32, y: i32, is_chinese: bool, is_upper: bool, caret_h: i32) {
+        let color = if is_upper {
+            // Caps Lock 开启，不管中英文都显示绿色
+            self.color_en_upper
+        } else if is_chinese {
+            // Caps Lock 关闭 + 中文模式 → 红色
             self.color_cn
         } else {
+            // Caps Lock 关闭 + 英文模式 → 蓝色
             self.color_en
         };