body {
  margin: 0;
  background-color: black;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  padding: 10px;
}

.calculator {
  background-color: #000;
  border-radius: 30px;
  padding: 20px;
  width: 90vw;
  max-width: 270px;
  box-shadow: 0 4px 20px rgba(255, 255, 255, 0.05);
  border: 2px solid #333;
}

.display {
  text-align: right;
  color: white;
  padding: 10px;
  overflow-x: auto;
}

.display::-webkit-scrollbar {
  display: none;
}

.expression {
  font-size: 1.2rem;
  color: gray;
  min-height: 20px;
  word-wrap: break-word;
}

.result {
  font-size: 2.5rem;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

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

.btn {
  font-size: 1.5rem;
  padding: 15px;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  color: white;
  transition: transform 0.1s ease;
}

.btn:active {
  transform: scale(0.95);
}

.gray {
  background-color: #a5a5a5;
  color: black;
}

.dark {
  background-color: #333;
}

.orange {
  background-color: #ff9500;
}

.zero {
  grid-column: span 2;
  border-radius: 40px;
  text-align: left;
  padding-left: 32px;
}

/* ✅ Media Query for Smaller Screens */
@media (max-width: 500px) {
  .calculator {
    width: 100%;
    padding: 15px;
  }

  .btn {
    font-size: 1.2rem;
    padding: 12px;
  }

  .expression {
    font-size: 1rem;
  }

  .result {
    font-size: 2rem;
  }
}