.calculator {
    width: 200px;
    margin: auto;
  }
  
  #display {
    width: 100%;
    height: 30px;
    font-size: 20px;
    text-align: right;
    padding: 5px;
    border: none;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
  }
  
  .buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 5px;
    margin-top: 10px;
  }
  
  button {
    height: 50px;
    width: 50px;
    font-size: 20px;
    border: none;
    border-radius: 50%;
    background-color: #f0f0f0;
    color: #222;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    transition: background 0.3s, color 0.3s, transform 0.2s;
    margin: auto;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  
  button:hover {
    background-color: #c2e9fb;
    color: #111;
    transform: scale(1.08);
    box-shadow: 0 4px 16px rgba(0,0,0,0.15);
  }

/* Mode toggle switch styling */
.mode-toggle-container {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  gap: 10px;
}
.switch {
  position: relative;
  display: inline-block;
  width: 50px;
  height: 28px;
}
.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}
.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #ccc;
  transition: 0.4s;
  border-radius: 34px;
}
.slider:before {
  position: absolute;
  content: "";
  height: 22px;
  width: 22px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: 0.4s;
  border-radius: 50%;
}
input:checked + .slider {
  background-color: #222;
}
input:checked + .slider:before {
  transform: translateX(22px);
}
#mode-label {
  font-size: 1rem;
  color: #333;
  transition: color 0.3s;
}

/* Light & Dark mode root styles */
body {
  background: #f9f9f9;
  color: #222;
  transition: background 0.4s, color 0.4s;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.calculator-wrapper {
  width: 380px;
  min-height: 560px;
  background: rgba(255,255,255,0.9);
  border-radius: 24px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.16);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 36px 24px 32px 24px;
  gap: 24px;
}

body.dark-mode .calculator-wrapper {
  background: #23272f;
  box-shadow: 0 0 18px rgba(0,0,0,0.25);
}

.mode-toggle-container, .calculator {
  width: 100%;
  max-width: 330px;
}

.mode-toggle-container {
  margin-bottom: 0;
  justify-content: center;
  padding-bottom: 8px;
}

.calculator {
  margin: 0 auto;
}

#display {
  font-size: 28px;
  height: 48px;
  margin-bottom: 12px;
}

.buttons {
  gap: 12px;
}

button {
  height: 60px;
  width: 60px;
  font-size: 22px;
}

body.dark-mode {
  background: #181a20;
  color: #f1f1f1;
}
body.dark-mode .calculator {
  background: #23272f;
}
body.dark-mode #display {
  background: #23272f;
  color: #fff;
}
body.dark-mode button {
  background: #2d323e;
  color: #f1f1f1;
}
body.dark-mode button:hover {
  background: #4b6cb7;
  color: #fff;
}
body.dark-mode #mode-label {
  color: #f1f1f1;
}