:root {
  --bg-color: #f3f3f3;
  --calc-bg: #ffffff;
  --text-color: #000;
  --border-color: #42a5f5;
  --btn-hover-scale: 1.1;
}

body.dark-mode {
  --bg-color: #1e1e1e;
  --calc-bg: #2c2c2c;
  --text-color: #fff;
  --border-color: #90caf9;
}
body {
  font-family: "Roboto", sans-serif;
  background-color: var(--bg-color);
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  transition: background 0.3s ease-in-out;
}

.calculadora {
  background: var(--calc-bg);
  padding: 20px 15px;
  border-radius: 12px;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
  width: 320px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  transition: background 0.3s ease-in-out;
}

.calculadora:hover {
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3); /* Sombra más intensa */
}

.pantalla {
  width: calc(100% - 20px);
  height: 70px;
  font-size: 2em;
  text-align: right;
  padding: 10px;
  border: 2px solid var(--border-color);
  background: var(--calc-bg);
  color: var(--text-color);
  border-radius: 10px;
  box-shadow: inset 0 4px 6px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease-in-out;
}

.botones {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin-top: 20px;
}

.boton {
  padding: 18px;
  font-size: 1.4em;
  font-weight: bold;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.boton:hover {
  transform: scale(var(--btn-hover-scale));
}

.boton:active {
  transform: scale(1);
  box-shadow: inset 0 4px 6px rgba(0, 0, 0, 0.2);
}

.boton.numero {
  background: #4caf50;
  color: white;
}

.boton.numero:hover {
  background: #43a047;
}

.boton.operacion {
  background: #ff7043;
  color: white;
}

.boton.operacion:hover {
  background: #f4511e;
}

.boton.edicion {
  background: #42a5f5;
  color: white;
}

.boton.edicion:hover {
  background: #1e88e5;
}

.boton.igual {
  background: #ffa000;
  color: white;
  grid-column: span 2;
  font-size: 1.6em;
  height: 60px;
}

.boton.igual:hover {
  background: #ff8f00;
}

.boton.porcentaje {
  background: #9c27b0;
  color: white;
}

.boton.porcentaje:hover {
  background: #7b1fa2;
}

.boton.tema {
  background: #757575;
  color: white;
  font-size: 1.2em;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 10px;
}

.boton.tema:hover {
  background: #616161;
}

@media (max-width: 480px) {
  .calculadora {
    width: 90%;
  }

  .boton {
    padding: 10px;
    font-size: 1em;
  }
}