@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600&display=swap');

body {
  margin: 0;
  font-family: 'Poppins', sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: linear-gradient(to right, #000000, #150537);
}

.calculator {
  background-color: #1e1e2f;
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  width: 360px;
  padding: 30px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

#inp {
  width: 100%;
  height: 90px;
  background-color: #131320;
  border: none;
  border-radius: 10px;
  padding: 0 20px;
  font-size: 3.2em;
  color: #f5f5f5;
  text-align: right;
  box-sizing: border-box;
  overflow-x: auto;
  white-space: nowrap;
}

.calculator-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.button {
  background-color: #2e2e3e;
  color: #f2f2f2;
  border: none;
  border-radius: 12px;
  padding: 20px 0;
  font-size: 1.3em;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  text-align: center;
  line-height: 1;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.25);
}

.button:hover {
  background-color: #3d3d5c;
  box-shadow: 0 6px 10px rgba(0, 0, 0, 0.35);
}

.button:active {
  transform: scale(0.97);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.button.function-btn {
  color: #8ab6d6;
}

.button.operator {
  color: #f1c40f;
  font-weight: 600;
}

.button.equals.enter {
  background-color: #27ae60;
  color: #fff;
  grid-column: span 2;
  font-size: 1.6em;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

.button.equals.enter:hover {
  background-color: #219653;
}

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