/*
#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>


#define TFT_CS   10
#define TFT_DC    9
#define TFT_RST   8
Adafruit_ILI9341 tft(TFT_CS, TFT_DC, TFT_RST);


#define BT_UP     2
#define BT_DOWN   3
#define BT_OK     4
#define BT_BACK   5


const char* drinkNames[] = { "Red  TEA", "Green TEA", "Wulong TEA", "Milk  TEA" };
const uint8_t prices[]    = { 30,         35,          40,           45 };
const uint8_t N_DRINKS    = sizeof(prices);


const int16_t TFT_W = 320, TFT_H = 240;
const uint8_t TITLE_SIZE = 3;
const uint8_t ITEM_SIZE  = 2;
const uint8_t ROW_H      = 30;          // vertical gap


enum Page { SPLASH, MENU, PRICE } page = SPLASH;
uint8_t curIdx = 0, prevIdx = 0;


unsigned long splashStart, lastPoll;
const unsigned long debounceMs = 120;


void setup() {
  pinMode(BT_UP,   INPUT_PULLUP);
  pinMode(BT_DOWN, INPUT_PULLUP);
  pinMode(BT_OK,   INPUT_PULLUP);
  pinMode(BT_BACK, INPUT_PULLUP);

  tft.begin();
  tft.setRotation(1);                 // 320×240 landscape
  splashStart = millis();
}


void loop() {
  switch (page) {
    case SPLASH: splashScreen(); break;
    case MENU:   handleMenu();   break;
    case PRICE:  handlePrice();  break;
  }
}


void splashScreen() {
  static bool on = false;
  static unsigned long lastBlink = 0;

  if (millis() - lastBlink > 500) {
    lastBlink = millis();
    on = !on;
    tft.fillScreen(ILI9341_BLACK);
    if (on) {
      tft.setTextSize(4);
      tft.setTextColor(ILI9341_CYAN, ILI9341_BLACK);
      centerPrint("CTAS", TFT_H / 2 - 12);
    }
  }
  if (millis() - splashStart >= 3000) {
    page = MENU;
    drawStaticMenu();
    drawRow(curIdx, true);            // highlight first item
  }
}


void handleMenu() {
  if (millis() - lastPoll < debounceMs) return;
  lastPoll = millis();

  if (!digitalRead(BT_UP)) {
    prevIdx = curIdx;
    curIdx  = (curIdx == 0) ? N_DRINKS - 1 : curIdx - 1;
    drawRow(prevIdx, false);
    drawRow(curIdx,  true);
  } else if (!digitalRead(BT_DOWN)) {
    prevIdx = curIdx;
    curIdx  = (curIdx + 1) % N_DRINKS;
    drawRow(prevIdx, false);
    drawRow(curIdx,  true);
  } else if (!digitalRead(BT_OK)) {
    page = PRICE;
    drawPrice(curIdx);
  }
}


void handlePrice() {
  if (millis() - lastPoll < debounceMs) return;
  lastPoll = millis();

  if (!digitalRead(BT_BACK)) {
    page = MENU;
    drawStaticMenu();
    drawRow(curIdx, true);
  }
}


int rowY(uint8_t idx) {
  int listTop = (TFT_H - N_DRINKS * ROW_H) / 2;   // vertical center
  return listTop + idx * ROW_H;
}


void centerPrint(const char* txt, int y) {
  int16_t x1, y1; uint16_t w, h;
  tft.getTextBounds((char*)txt, 0, 0, &x1, &y1, &w, &h);
  int x = (TFT_W - w) / 2;
  tft.setCursor(x, y);
  tft.print(txt);
}


void drawStaticMenu() {
  tft.fillScreen(ILI9341_BLACK);

  
  tft.setTextSize(TITLE_SIZE);
  tft.setTextColor(ILI9341_YELLOW, ILI9341_BLACK);
  centerPrint("Drink Menu", (TFT_H - N_DRINKS*ROW_H)/2 - 40);

  
  tft.setTextSize(ITEM_SIZE);
  for (uint8_t i = 0; i < N_DRINKS; i++)
    drawRow(i, i == curIdx);   // highlight current for first load
}


void drawRow(uint8_t idx, bool highlight) {
  
  tft.setTextSize(ITEM_SIZE);
  int16_t x1, y1; uint16_t w, h;
  tft.getTextBounds((char*)drinkNames[idx], 0, 0, &x1, &y1, &w, &h);

  const uint8_t pad = 6;
  int x = (TFT_W - w) / 2;
  int y = rowY(idx);

  
  uint16_t bg = highlight ? ILI9341_YELLOW : ILI9341_BLACK;
  uint16_t fg = highlight ? ILI9341_BLACK  : ILI9341_WHITE;

  
  tft.fillRect(x - pad, y - 2, w + pad*2, h + 4, bg);

  
  tft.setTextColor(fg, bg);
  tft.setCursor(x, y);
  tft.print(drinkNames[idx]);
}


void drawPrice(uint8_t idx) {
  tft.fillScreen(ILI9341_BLACK);

  tft.setTextSize(3);
  tft.setTextColor(ILI9341_CYAN, ILI9341_BLACK);
  centerPrint(drinkNames[idx], TFT_H/2 - 40);

  char buf[12];
  sprintf(buf, "$%d", prices[idx]);
  tft.setTextSize(4);
  tft.setTextColor(ILI9341_WHITE, ILI9341_BLACK);
  centerPrint(buf, TFT_H/2 + 10);

  tft.setTextSize(1);
  tft.setTextColor(ILI9341_LIGHTGREY, ILI9341_BLACK);
  centerPrint("(Press BACK)", TFT_H - 20);
}
*/
/* =====================================================
   COLOR Menu on ILI9341 TFT  ‒  4‑Button Navigation
   Requires: Adafruit_GFX + Adafruit_ILI9341 libraries
   ===================================================== */
/* =====================================================
   COLOR Menu (Arrow Cursor) ‒ ILI9341 + 4 Buttons
   Libraries: Adafruit_GFX, Adafruit_ILI9341
   ===================================================== */

/* =====================================================
   COLOR Menu － Triangle Cursor  (No residual artifacts)
   ===================================================== */

   
/*
#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>

// ---- TFT SPI pins ---- 
#define TFT_CS   10
#define TFT_DC    9
#define TFT_RST   8
Adafruit_ILI9341 tft(TFT_CS, TFT_DC, TFT_RST);

// ---- Button pins ---- 
#define BT_UP     2
#define BT_DOWN   3
#define BT_OK     4
#define BT_BACK   5

// ---- Color table ---- 
const char*    colorNames[] = { "Red", "Green", "Blue", "Black", "White" };
const uint16_t colorVals[]  = { ILI9341_RED, ILI9341_GREEN,
                                ILI9341_BLUE, ILI9341_BLACK,
                                ILI9341_WHITE };
const uint8_t  N_COLORS = sizeof(colorVals) / sizeof(colorVals[0]);

// ---- Layout ---- 
const int16_t TFT_W = 320, TFT_H = 240;
const uint8_t TITLE_SIZE = 3;
const uint8_t ITEM_SIZE  = 2;
const uint8_t ROW_H      = 30;
const int16_t TRI_X      = 40;   // 三角形左側 x 座標
const uint8_t TRI_W      = 12;   // 三角形寬

// ---- State ---- 
enum Page { SPLASH, MENU, SHOW_COLOR } page = SPLASH;
uint8_t curIdx = 0, prevIdx = 0;

// ---- Timing ---- 
unsigned long splashStart, lastPoll;
const unsigned long debounceMs = 120;

// -------------------- Setup -------------------- 
void setup()
 {
  pinMode(BT_UP,   INPUT_PULLUP);
  pinMode(BT_DOWN, INPUT_PULLUP);
  pinMode(BT_OK,   INPUT_PULLUP);
  pinMode(BT_BACK, INPUT_PULLUP);

  tft.begin();
  tft.setRotation(3);
  splashStart = millis();
}

// -------------------- Loop -------------------- 
void loop() {
  switch (page) {
    case SPLASH:      splash();      break;
    case MENU:        menuLoop();    break;
    case SHOW_COLOR:  colorLoop();   break;
  }
}

// ========== Splash Screen ========== 
void splash() {
  static bool on = false;
  static unsigned long lastBlink = 0;

  if (millis() - lastBlink > 500) {
    lastBlink = millis();
    on = !on;
    tft.fillScreen(ILI9341_BLACK);
    if (on) {
      tft.setTextSize(4);
      tft.setTextColor(ILI9341_CYAN, ILI9341_BLACK);
      centerPrint("CTAS", TFT_H / 2 - 12);
    }
  }
  if (millis() - splashStart >= 3000) {
    page = MENU;
    drawMenuBase();
    drawRow(curIdx, true);
  }
}

// ========== Menu ========== 
void menuLoop() {
  if (millis() - lastPoll < debounceMs) return;
  lastPoll = millis();

  if (!digitalRead(BT_UP)) {
    prevIdx = curIdx;
    curIdx  = (curIdx == 0) ? N_COLORS - 1 : curIdx - 1;
    drawRow(prevIdx, false);
    drawRow(curIdx,  true);
  } else if (!digitalRead(BT_DOWN)) {
    prevIdx = curIdx;
    curIdx  = (curIdx + 1) % N_COLORS;
    drawRow(prevIdx, false);
    drawRow(curIdx,  true);
  } else if (!digitalRead(BT_OK)) {
    page = SHOW_COLOR;
    showColor(curIdx);
  }
}

// ========== Color Page ========== 
void colorLoop() {
  if (millis() - lastPoll < debounceMs) return;
  lastPoll = millis();

  if (!digitalRead(BT_BACK)) {
    page = MENU;
    drawMenuBase();
    drawRow(curIdx, true);
  }
}

// ---------- Helpers ---------- 
int rowY(uint8_t idx) {
  int listTop = (TFT_H - N_COLORS * ROW_H) / 2;
  return listTop + idx * ROW_H;
}

void centerPrint(const char* txt, int y) {
  int16_t x1, y1; uint16_t w, h;
  tft.getTextBounds((char*)txt, 0, 0, &x1, &y1, &w, &h);
  int x = (TFT_W - w) / 2;
  tft.setCursor(x, y);
  tft.print(txt);
}

// Draw static parts (title + list without cursor) 
void drawMenuBase() {
  tft.fillScreen(ILI9341_BLACK);

  tft.setTextSize(TITLE_SIZE);
  tft.setTextColor(ILI9341_YELLOW, ILI9341_BLACK);
  centerPrint("COLOR Menu", (TFT_H - N_COLORS*ROW_H)/2 - 40);

  tft.setTextSize(ITEM_SIZE);
  for (uint8_t i = 0; i < N_COLORS; i++)
    drawRow(i, i == curIdx);   // 只有 current 會立即畫三角
}

// Draw / erase a single row 
void drawRow(uint8_t idx, bool drawTri) {
  tft.setTextSize(ITEM_SIZE);

  // 計算文字置中位置 
  int16_t x1, y1; uint16_t w, h;
  tft.getTextBounds((char*)colorNames[idx], 0, 0, &x1, &y1, &w, &h);
  int textX = (TFT_W - w) / 2;
  int y     = rowY(idx);

  // (1) 清除舊三角區域(保留黑底) 
  tft.fillRect(TRI_X, y - 2, TRI_W, h + 4, ILI9341_BLACK);

  // (2) 輸出白字項目名稱 
  tft.setTextColor(ILI9341_WHITE, ILI9341_BLACK);
  tft.setCursor(textX, y);
  tft.print(colorNames[idx]);

  // (3) 若需三角游標，畫實心右向三角形 
  if (drawTri) {
    int triYmid = y + h / 2;
    tft.fillTriangle(
      TRI_X,            triYmid - 6,     // 上端點
      TRI_X,            triYmid + 6,     // 下端點
      TRI_X + TRI_W,    triYmid,         // 右端點 (箭頭尖)
      ILI9341_YELLOW);
  }
}

// Show full‑screen color 
void showColor(uint8_t idx) {
  uint16_t bg = colorVals[idx];
  tft.fillScreen(bg);

  uint16_t fg = (bg == ILI9341_WHITE) ? ILI9341_BLACK : ILI9341_WHITE;
  tft.setTextColor(fg, bg);

  tft.setTextSize(4);
  centerPrint(colorNames[idx], TFT_H / 2 - 12);

  tft.setTextSize(1);
  centerPrint("(Press BACK)", TFT_H - 20);
}
*/

#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <Adafruit_NeoPixel.h>

// ---------- TFT Pins (ILI9341 SPI) ----------
#define TFT_CS   10
#define TFT_DC    9
#define TFT_RST   8
Adafruit_ILI9341 tft(TFT_CS, TFT_DC, TFT_RST);

// ---------- NeoPixel ----------
#define LED_PIN     6
#define NUM_LEDS    8
Adafruit_NeoPixel strip(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);

// ---------- Buttons (INPUT_PULLUP) ----------
#define BTN_UP      2
#define BTN_DOWN    3
#define BTN_OK      4
#define BTN_BACK    5

// 改良按鍵：邊沿偵測 + 長按自動重複
struct Btn {
  uint8_t pin; bool last; unsigned long lastTs; unsigned long repeatTs;
  Btn(): pin(0), last(HIGH), lastTs(0), repeatTs(0) {}
  Btn(uint8_t p): pin(p), last(HIGH), lastTs(0), repeatTs(0) {}
};
Btn bUp(BTN_UP), bDown(BTN_DOWN), bOk(BTN_OK), bBack(BTN_BACK);
const unsigned long DEBOUNCE_MS = 60;
const unsigned long REPEAT_DELAY = 400;
const unsigned long REPEAT_RATE  = 140;

bool pressed(Btn &b){
  bool now = digitalRead(b.pin); unsigned long t=millis(); bool fire=false;
  if (b.last==HIGH && now==LOW && (t-b.lastTs)>DEBOUNCE_MS){ fire=true; b.repeatTs=t+REPEAT_DELAY; b.lastTs=t; }
  if (now==LOW && b.last==LOW && b.repeatTs && t>=b.repeatTs){ fire=true; b.repeatTs+=REPEAT_RATE; }
  if (b.last==LOW && now==HIGH){ b.repeatTs=0; b.lastTs=t; }
  b.last=now; return fire;
}

// ---------- App State ----------
enum Screen { SCR_MENU, SCR_SOLID_SUB, SCR_BRIGHTNESS, SCR_SPEED, SCR_ABOUT };
enum Mode   { MODE_OFF, MODE_SOLID, MODE_CHASE, MODE_RAINBOW };
Screen screen = SCR_MENU;
Mode   mode   = MODE_OFF;

// ---------- Menu model ----------
const char* menuItems[] = {
  "Solid Color", "Purple Chase", "Rainbow Cycle", "Brightness", "Speed", "About"
};
const uint8_t MENU_SIZE = sizeof(menuItems)/sizeof(menuItems[0]);
int menuIndex = 0, lastMenuIndex = 0;

struct ColorItem { const char* name; uint32_t color; };
ColorItem solidItems[] = {
  {"Red",     Adafruit_NeoPixel::Color(255,   0,   0)},
  {"Green",   Adafruit_NeoPixel::Color(  0, 255,   0)},
  {"Blue",    Adafruit_NeoPixel::Color(  0,   0, 255)},
  {"Yellow",  Adafruit_NeoPixel::Color(255, 255,   0)},
  {"Cyan",    Adafruit_NeoPixel::Color(  0, 255, 255)},
  {"Magenta", Adafruit_NeoPixel::Color(255,   0, 255)},
  {"White",   Adafruit_NeoPixel::Color(255, 255, 255)},
  {"Off",     Adafruit_NeoPixel::Color(  0,   0,   0)}
};
const uint8_t SOLID_SIZE = sizeof(solidItems)/sizeof(solidItems[0]);
int  solidIndex = 0, lastSolidIndex = 0;

// ---------- Parameters ----------
uint8_t  brightness = 220;   // 更亮
uint16_t speedMs    = 100;
const uint16_t SPEED_MIN = 30, SPEED_MAX = 300, SPEED_STEP = 10;

// ---------- Animation state ----------
unsigned long animTs = 0;
uint16_t rainbowHue = 0;
int chasePos = 0;

// ---------- UI layout（直立） ----------
const int TITLE_H = 24;
const int LINE_H  = 26;

int firstLineY(uint8_t itemCount){
  int contentH = itemCount * LINE_H;
  int avail = tft.height() - TITLE_H;
  int top = TITLE_H + (avail - contentH)/2;
  if (top < TITLE_H) top = TITLE_H;
  return top;
}

int centerX(const char* text, int textSize=2){
  int16_t x1,y1; uint16_t w,h;
  tft.setTextSize(textSize);
  tft.getTextBounds(text, 0, 0, &x1, &y1, &w, &h);
  int x = (tft.width() - w)/2;
  return (x < 0) ? 0 : x;
}

void drawHeaderStatic(const char* title){
  tft.fillScreen(ILI9341_BLACK);
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(2);
  tft.setCursor(centerX(title,2), 4);
  tft.print(title);
  tft.drawFastHLine(0, TITLE_H, tft.width(), ILI9341_WHITE);
}

void drawRowCentered(int rowY, const char* text, bool selected){
  uint16_t bg = selected ? ILI9341_BLUE : ILI9341_BLACK;
  uint16_t fg = selected ? ILI9341_WHITE: ILI9341_YELLOW;
  tft.fillRect(0, rowY-2, tft.width(), LINE_H, bg);
  tft.setTextColor(fg);
  tft.setTextSize(2);
  tft.setCursor(centerX(text,2), rowY);
  tft.print(text);
}

void drawMenuStatic(){
  drawHeaderStatic("RGB MENU");
  int y = firstLineY(MENU_SIZE);
  for (int i=0;i<MENU_SIZE;i++){
    drawRowCentered(y, menuItems[i], i==menuIndex);
    y += LINE_H;
  }
  tft.drawFastHLine(0, tft.height()-18, tft.width(), ILI9341_WHITE);
  tft.setTextSize(1); tft.setTextColor(ILI9341_WHITE);
  tft.setCursor(6, tft.height()-14);
  tft.print("Bri:"); tft.print(brightness);
  tft.print("  Spd:"); tft.print(speedMs);
}

void updateMenuSelection(int prev, int curr){
  if (prev==curr) return;
  int base = firstLineY(MENU_SIZE);
  drawRowCentered(base + prev*LINE_H, menuItems[prev], false);
  drawRowCentered(base + curr*LINE_H, menuItems[curr], true);
}

// ---- Solid Color：含彩色小方塊 ----
void drawRowSolidCentered(int rowY, const char* text, uint32_t rgb, bool selected){
  uint16_t bg = selected ? ILI9341_BLUE : ILI9341_BLACK;
  uint16_t fg = selected ? ILI9341_WHITE: ILI9341_YELLOW;
  tft.fillRect(0, rowY-2, tft.width(), LINE_H, bg);

  uint8_t r = (rgb >> 16) & 0xFF;
  uint8_t g = (rgb >>  8) & 0xFF;
  uint8_t b = (rgb      ) & 0xFF;
  uint16_t c565 = ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | (b >> 3);
  int sw = 22, sh = LINE_H-6;
  int swX = 10, swY = rowY - (sh/2) + 6;
  tft.fillRect(swX, swY, sw, sh, c565);
  tft.drawRect(swX-1, swY-1, sw+2, sh+2, selected ? ILI9341_WHITE : ILI9341_DARKGREY);

  tft.setTextColor(fg);
  tft.setTextSize(2);
  int16_t x1,y1; uint16_t w,h;
  tft.getTextBounds(text, 0, 0, &x1, &y1, &w, &h);
  int textX = max(swX + sw + 12, (tft.width() - (int)w)/2);
  tft.setCursor(textX, rowY);
  tft.print(text);
}

void drawSolidStatic(){
  drawHeaderStatic("Solid Color");
  int y = firstLineY(SOLID_SIZE);
  for (int i=0;i<SOLID_SIZE;i++){
    drawRowSolidCentered(y, solidItems[i].name, solidItems[i].color, i==solidIndex);
    y += LINE_H;
  }
  tft.setTextSize(1); tft.setTextColor(ILI9341_WHITE);
  const char* hint = "UP/DOWN=Select  OK=Apply  BACK=Menu";
  tft.setCursor(centerX(hint,1), tft.height()-14);
  tft.print(hint);
}

void updateSolidSelection(int prev, int curr){
  if (prev==curr) return;
  int base = firstLineY(SOLID_SIZE);
  drawRowSolidCentered(base + prev*LINE_H,
                       solidItems[prev].name, solidItems[prev].color, false);
  drawRowSolidCentered(base + curr*LINE_H,
                       solidItems[curr].name, solidItems[curr].color, true);
}

void drawNumberAdjust(const char* title, int value, int vmin, int vmax, int step, const char* unit=""){
  drawHeaderStatic(title);
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(4);
  char buf[20];
  if (unit && unit[0]) sprintf(buf, "%d %s", value, unit);
  else sprintf(buf, "%d", value);
  int x = centerX(buf,4);
  int y = TITLE_H + (tft.height()-TITLE_H)/2 - 16;
  tft.fillRect(0, TITLE_H+10, tft.width(), tft.height()-TITLE_H-40, ILI9341_BLACK);
  tft.setCursor(x, y); tft.print(buf);

  tft.setTextSize(2);
  const char* hint = "UP/DOWN=Adjust  OK=Save  BACK=Exit";
  tft.setCursor(centerX(hint,2), tft.height()-60); tft.print(hint);
  char rangeBuf[40]; sprintf(rangeBuf,"Range: %d~%d (%d)", vmin, vmax, step);
  tft.setCursor(centerX(rangeBuf,2), tft.height()-32); tft.print(rangeBuf);
}

void drawAbout(){
  drawHeaderStatic("About");
  tft.setTextColor(ILI9341_WHITE); tft.setTextSize(2);
  const char* l1="School : CTAS";
  const char* l2="Project: RGB Menu + WS2812";
  const char* l3="Author : _______";
  const char* l4="Date   : 2025-08-13";
  int y = TITLE_H + 30;
  tft.setCursor(centerX(l1,2), y);       tft.print(l1);
  tft.setCursor(centerX(l2,2), y+28);    tft.print(l2);
  tft.setCursor(centerX(l3,2), y+56);    tft.print(l3);
  tft.setCursor(centerX(l4,2), y+84);    tft.print(l4);
  tft.setTextSize(1);
  const char* back="BACK=menu";
  tft.setCursor(centerX(back,1), tft.height()-14); tft.print(back);
}

// ---------- LED helpers ----------
void applyBrightness(){ strip.setBrightness(brightness); strip.show(); }
void showSolid(uint32_t c){ for (int i=0;i<NUM_LEDS;i++) strip.setPixelColor(i,c); strip.show(); }
uint32_t brightPurple(){ return strip.Color(255,0,255); }

// ---------- Animations ----------
void animChase(){
  if (millis()-animTs < speedMs) return;
  animTs = millis();
  for (int i=0;i<NUM_LEDS;i++) strip.setPixelColor(i,0);
  strip.setPixelColor(chasePos, brightPurple());
  strip.show();
  chasePos = (chasePos + 1) % NUM_LEDS;
}
uint32_t colorWheel(uint16_t hue){
  uint8_t p=(hue>>8)&0xFF;
  if (p<85)   return strip.Color(255-p*3, p*3, 0);
  if (p<170){ p-=85; return strip.Color(0, 255-p*3, p*3); }
  p-=170;     return strip.Color(p*3, 0, 255-p*3);
}
void animRainbow(){
  if (millis()-animTs < speedMs) return;
  animTs = millis();
  for (int i=0;i<NUM_LEDS;i++){
    uint16_t h = rainbowHue + (i * 65535UL / NUM_LEDS);
    strip.setPixelColor(i, colorWheel(h));
  }
  strip.show();
  rainbowHue += 1024;
}

// ---------- Setup ----------
void setup(){
  pinMode(BTN_UP,INPUT_PULLUP); pinMode(BTN_DOWN,INPUT_PULLUP);
  pinMode(BTN_OK,INPUT_PULLUP); pinMode(BTN_BACK,INPUT_PULLUP);

  tft.begin();
  tft.setRotation(0);                  // 直立（240x320）
  tft.fillScreen(ILI9341_BLACK);

  strip.begin(); strip.setBrightness(brightness); strip.show();

  drawHeaderStatic("CTAS RGB Controller");
  tft.setTextColor(ILI9341_GREEN); tft.setTextSize(3);
  const char* hello="Welcome!";
  tft.setCursor(centerX(hello,3), TITLE_H + (tft.height()-TITLE_H)/2 - 16);
  tft.print(hello);
  delay(3000);

  drawMenuStatic();
}

// ---------- Loop ----------
void loop(){
  bool up=pressed(bUp), down=pressed(bDown), ok=pressed(bOk), back=pressed(bBack);

  switch (screen){
    case SCR_MENU:{
      if (up){   lastMenuIndex = menuIndex; menuIndex = (menuIndex-1+MENU_SIZE)%MENU_SIZE; updateMenuSelection(lastMenuIndex, menuIndex); }
      if (down){ lastMenuIndex = menuIndex; menuIndex = (menuIndex+1)%MENU_SIZE;           updateMenuSelection(lastMenuIndex, menuIndex); }
      if (ok){
        if (menuIndex==0){
          // ★ 變更點：進入 Solid Color 後「直接顯示目前索引顏色」，且「不回主選單」
          screen=SCR_SOLID_SUB;
          drawSolidStatic();
          showSolid(solidItems[solidIndex].color);
          mode = (solidItems[solidIndex].color == 0) ? MODE_OFF : MODE_SOLID;
        }
        else if (menuIndex==1){ mode=MODE_CHASE;   chasePos=0; }
        else if (menuIndex==2){ mode=MODE_RAINBOW; rainbowHue=0; }
        else if (menuIndex==3){ screen=SCR_BRIGHTNESS; drawNumberAdjust("Brightness", brightness, 0, 255, 8); }
        else if (menuIndex==4){ screen=SCR_SPEED;      drawNumberAdjust("Speed (ms)", speedMs, SPEED_MIN, SPEED_MAX, SPEED_STEP, "ms"); }
        else if (menuIndex==5){ screen=SCR_ABOUT;      drawAbout(); }
      }
      if (mode==MODE_CHASE)   animChase();
      if (mode==MODE_RAINBOW) animRainbow();
      break;
    }

    case SCR_SOLID_SUB:{
      if (up){
        lastSolidIndex = solidIndex;
        solidIndex = (solidIndex - 1 + SOLID_SIZE) % SOLID_SIZE;
        updateSolidSelection(lastSolidIndex, solidIndex);
        // 即時預覽（不需 OK）
        showSolid(solidItems[solidIndex].color);
        mode = (solidItems[solidIndex].color == 0) ? MODE_OFF : MODE_SOLID;
      }
      if (down){
        lastSolidIndex = solidIndex;
        solidIndex = (solidIndex + 1) % SOLID_SIZE;
        updateSolidSelection(lastSolidIndex, solidIndex);
        // 即時預覽
        showSolid(solidItems[solidIndex].color);
        mode = (solidItems[solidIndex].color == 0) ? MODE_OFF : MODE_SOLID;
      }
      if (ok){
        // ★ 變更點：按 OK「只套用」，但「不離開」固色子選單
        showSolid(solidItems[solidIndex].color);
        mode = (solidItems[solidIndex].color == 0) ? MODE_OFF : MODE_SOLID;
        // 保持在 SCR_SOLID_SUB，不跳走
      }
      if (back){
        screen = SCR_MENU;
        drawMenuStatic();
      }
      break;
    }

    case SCR_BRIGHTNESS:{
      static int tmp = brightness;
      if (up){   tmp = min(255, tmp+8); drawNumberAdjust("Brightness", tmp, 0, 255, 8); }
      if (down){ tmp = max(0,   tmp-8); drawNumberAdjust("Brightness", tmp, 0, 255, 8); }
      if (ok){   brightness = tmp; applyBrightness(); screen=SCR_MENU; drawMenuStatic(); }
      if (back){ screen=SCR_MENU; drawMenuStatic(); }
      if (mode==MODE_CHASE) animChase(); if (mode==MODE_RAINBOW) animRainbow();
      break;
    }

    case SCR_SPEED:{
      static int tmp = speedMs;
      if (up){   tmp = min((int)SPEED_MAX, tmp+SPEED_STEP); drawNumberAdjust("Speed (ms)", tmp, SPEED_MIN, SPEED_MAX, SPEED_STEP, "ms"); }
      if (down){ tmp = max((int)SPEED_MIN, tmp-SPEED_STEP); drawNumberAdjust("Speed (ms)", tmp, SPEED_MIN, SPEED_MAX, SPEED_STEP, "ms"); }
      if (ok){   speedMs = tmp; screen=SCR_MENU; drawMenuStatic(); }
      if (back){ screen=SCR_MENU; drawMenuStatic(); }
      if (mode==MODE_CHASE) animChase(); if (mode==MODE_RAINBOW) animRainbow();
      break;
    }

    case SCR_ABOUT:{
      if (back || ok){ screen=SCR_MENU; drawMenuStatic(); }
      if (mode==MODE_CHASE) animChase(); if (mode==MODE_RAINBOW) animRainbow();
      break;
    }
  }
}