* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}

body {
  background: linear-gradient(145deg, #0f0f0f, #1a1a1a);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.calculator {
  background: rgb(38, 35, 35);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 20px;
  width: 100%;
  max-width: 360px;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.display {
  background: rgba(255, 255, 255, 0.05);
  border-radius: 12px;
  padding: 16px;
  font-size: 28px;
  color: #ffffff;
  text-align: right;
  margin-bottom: 20px;
  min-height: 60px;
  overflow: hidden;
  word-wrap: break-word;
}

.buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

button {
  padding: 18px;
  border: none;
  border-radius: 15px;
  font-size: 18px;
  background: rgba(255, 255, 255, 0.07);
  color: #ffffff;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

button:hover {
  background: rgba(255, 255, 255, 0.15);
  transform: scale(1.05);
}

.operator {
  color: #00bcd4;
  font-weight: bold;
}

.equal {
  background: #00bcd4;
  color: #000;
  font-weight: bold;
}

.equal:hover {
  background: #00acc1;
}

.clear {
  color: #ff5252;
}

.clear:hover {
  background: rgba(255, 82, 82, 0.2);
}

/* Small screens */
@media (max-width: 480px) {
  .calculator {
    padding: 15px;
    border-radius: 15px;
  }

  .display {
    font-size: 22px;
    padding: 12px;
    min-height: 50px;
  }

  button {
    padding: 14px;
    font-size: 14px;
    border-radius: 10px;
  }

  .buttons {
    gap: 8px;
  }
}

/*small screens */
@media (max-width: 360px) {
  .display {
    font-size: 18px;
  }

  button {
    padding: 12px;
    font-size: 13px;
  }
}