import React, { useState } from "react";

export default function App() {
  const [input, setInput] = useState("");

  const handleClick = (value) => {
    if (value === "C") {
      setInput("");
    } else if (value === "=") {
      try {
        // Evalúa la expresión de forma segura
        // eslint-disable-next-line no-eval
        setInput(eval(input).toString());
      } catch {
        setInput("Error");
      }
    } else {
      setInput(input + value);
    }
  };

  const buttons = [
    "7", "8", "9", "/",
    "4", "5", "6", "*",
    "1", "2", "3", "-",
    "0", ".", "C", "+",
    "=",
  ];

  return (
    <div className="min-h-screen flex items-center justify-center bg-gray-900">
      <div className="bg-gray-800 p-6 rounded-2xl shadow-2xl w-80">
        <div className="bg-black text-right text-white text-3xl p-4 rounded-lg mb-4 h-16 overflow-x-auto">
          {input || "0"}
        </div>
        <div className="grid grid-cols-4 gap-3">
          {buttons.map((btn) => (
            <button
              key={btn}
              onClick={() => handleClick(btn)}
              className={`text-white text-xl py-3 rounded-xl transition 
              ${
                btn === "="
                  ? "col-span-4 bg-green-500 hover:bg-green-600"
                  : btn === "C"
                  ? "bg-red-500 hover:bg-red-600"
                  : "bg-gray-700 hover:bg-gray-600"
              }`}
            >
              {btn}
            </button>
          ))}
        </div>
      </div>
    </div>
  );
}