@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@300&family=Ubuntu:wght@300&display=swap');
html, body {
  height: 100%;
  width: 100%;
  font-family: 'Roboto', sans-serif; 
  background-color: #f5f5f5;
}

.button{
  width: 66px;
  padding: 20px;
  margin: 0 3px;
  border: 2px solid #333;
  border-radius: 9px;
  cursor: pointer;
  font-size: 18px;
  font-weight: bold;
  background-color: #f0f0f0;
  transition: all 0.2s;
}

.button:hover {
  background-color: #e0e0e0;
}

.button:active {
  transform: scale(0.98);
}

.row{
  margin: 8px 0;
  display: flex;
  justify-content: center;
}

.row input{
  width: 291px;
  font-size: 24px;
  margin: 0;
  padding: 15px 10px;
  border: 2px solid #333;
  border-radius: 5px;
  text-align: right;
  background-color: #fff;
}

.container {
  background-color: white;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

h1 {
  color: #333;
  margin-bottom: 20px;
}

/* Operator buttons */
.button:last-child {
  background-color: #ff9500;
  color: white;
}

/* Equal button */
.row:last-child .button:nth-child(3) {
  background-color: #4CAF50;
  color: white;
}

/* Clear button */
.row:nth-child(2) .button:first-child {
  background-color: #f44336;
  color: white;
}

/* Memory buttons */
.row:nth-child(2) .button:nth-child(3),
.row:nth-child(2) .button:nth-child(4) {
  background-color: #2196F3;
  color: white;
}