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

body {
  background: linear-gradient(135deg, #1e1e30, #3a3a50);
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

.calculator {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  padding: 20px;
  border-radius: 20px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
  width: 350px;
}

#display {
  width: 100%;
  height: 60px;
  border: none;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  font-size: 28px;
  text-align: right;
  padding: 15px;
  margin-bottom: 20px;
  outline: none;
}

.buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 15px;
}

button {
  padding: 20px;
  font-size: 18px;
  background-color: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #fff;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.2s ease;
}

button:hover {
  background-color: rgba(255, 255, 255, 0.2);
  transform: scale(1.05);
}

button.zero {
  grid-column: span 2;
}

button.equals {
  background-color: #8a2be2;
  color: #fff;
  font-weight: bold;
}

button.equals:hover {
  background-color: #a855f7;
}

.btn-ac {
  color: #ff5c5c;
}