/* ==========================================
   SIMPLE CALCULATOR - STYLES (style.css)
   This file only changes HOW things look.
   It never changes what the calculator does.
   ========================================== */

body {
  font-family: Arial, sans-serif;
  background: #2c3e50;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
}

/* The calculator "box" that holds everything */
.calculator {
  background: #ecf0f1;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 8px 24px rgba(0,0,0,.4);
}

/* The screen where numbers appear */
#display {
  width: 260px;
  height: 60px;
  font-size: 28px;
  text-align: right;
  padding: 0 10px;
  margin-bottom: 12px;
  border: 2px solid #bdc3c7;
  border-radius: 8px;
  background: #fff;
  box-sizing: border-box;
}

/* The grid of buttons: 4 columns */
.buttons {
  display: grid;
  grid-template-columns: repeat(4, 64px);
  gap: 8px;
}

button {
  height: 56px;
  font-size: 20px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  background: #dfe6e9;
}

button:hover { background: #b2bec3; }

/* Special colors for special buttons */
.operator  { background: #74b9ff; }
.equals    { background: #55efc4; grid-column: span 2; }
.clear     { background: #ff7675; color: #fff; }
.backspace { background: #fdcb6e; }