body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.container h1 {
  text-align: center;
  font-size: 1.8rem;
  font-weight: 600;
  color: white;
  letter-spacing: 2px;
  margin-bottom: 25px;
}

.container {
  display: flex;
  gap: 30px;
  background: #1e293b;
  padding: 30px;
  border-radius: 20px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.4);
}


.calculator-area {
  width: 400px;
}

.calculadora {
  width: 100%;
  border-collapse: separate;
  border-spacing: 12px;
}

.display {
  width: 100%;
  height: 80px;
  font-size: 2rem;
  text-align: right;
  padding: 15px;
  border-radius: 12px;
  border: none;
  background: #0f172a;
  color: white;
}

.btn {
  width: 100%;
  height: 70px;
  font-size: 1.3rem;
  border: none;
  border-radius: 15px;
  cursor: pointer;
  background: #334155;
  color: white;
  transition: 0.2s ease;
}

.btn:hover {
  background: #475569;
}

.btn-eq {
  background: #22c55e;
}

.btn-clear {
  background: #ef4444;
}


.historico {
  width: 250px;
  background: #0f172a;
  border-radius: 15px;
  padding: 15px;
  color: white;
  overflow-y: auto;
  max-height: 500px;
}

.historico h2 {
  text-align: center;
  margin-bottom: 10px;
}

.historico-lista {
  list-style: none;
  padding: 0;
}

.historico-lista li {
  padding: 8px;
  border-bottom: 1px solid #334155;
  font-size: 0.9rem;
}

@media (max-width: 900px) {
  .container {
    flex-direction: column;
    align-items: center;
  }

  .historico {
    width: 100%;
    max-height: 200px;
  }

  .calculator-area {
    width: 100%;
  }
}