project with ui part - Wokwi ESP32, STM32, Arduino Simulator

#include <WiFi.h>
#include <WebServer.h>
#include <DHT.h>

#define DHTPIN 4
#define DHTTYPE DHT22
#define MQ135_PIN 34

const char* ssid = "FST-B";          // Your WiFi SSID
const char* password = "WiFi$2026";  // Your WiFi password

WebServer server(80);
DHT dht(DHTPIN, DHTTYPE);

int airValue;
float temperature;
float humidity;

String getAirQuality(int value) {
  if (value < 1000) return "Good";
  else if (value < 2000) return "Moderate";
  else return "Poor";
}

void handleRoot() {
  airValue = analogRead(MQ135_PIN);
  temperature = dht.readTemperature();
  humidity = dht.readHumidity();

  String airStatus = getAirQuality(airValue);

  String html = "<!DOCTYPE html><html>";
  html += "<head><meta http-equiv='refresh' content='2'>";
  html += "<title>Air Quality Monitor</title>";
  html += "<style>";
  html += "body { font-family: Arial; text-align: center; background-color: #f4f4f4; }";
  html += "h1 { color: #333; }";
  html += ".card { background: white; padding: 20px; margin: 20px auto; width: 300px; border-radius: 10px; box-shadow: 0 4px 8px rgba(0,0,0,0.2);} ";
  html += "</style></head><body>";

  html += "<h1>ESP32 Air Quality Monitoring</h1>";
  html += "<div class='card'>";
  html += "<h3>Air Value: " + String(airValue) + "</h3>";
  html += "<h3>Status: " + airStatus + "</h3>";
  html += "<h3>Temperature: " + String(temperature) + " °C</h3>";
  html += "<h3>Humidity: " + String(humidity) + " %</h3>";
  html += "</div></body></html>";

  server.send(200, "text/html", html);
}

void setup() {
  Serial.begin(115200);
  dht.begin();

  Serial.println("Connecting to WiFi: " + String(ssid));
  WiFi.begin(ssid, password);

  int retries = 0;
  while (WiFi.status() != WL_CONNECTED && retries < 20) {  // Try 20 times (~10 seconds)
    delay(500);
    Serial.print(".");
    retries++;
  }

  if (WiFi.status() == WL_CONNECTED) {
    Serial.println("\nConnected to WiFi!");
    Serial.print("ESP32 IP Address: ");
    Serial.println(WiFi.localIP());
  } else {
    Serial.println("\nFailed to connect to WiFi.");
  }

  server.on("/", handleRoot);
  server.begin();
  Serial.println("HTTP server started");
}

void loop() {
  server.handleClient();
}