:root {
  --primary: #005fae;
  --onPrimary: #ffffff;
  --primaryContainer: #d3e4ff;
  --onPrimaryContainer: #001c3b;
  --secondary: #4c5f7c;
  --onSecondary: #ffffff;
  --secondaryContainer: #d3e4ff;
  --onSecondaryContainer: #051c35;
  --tertiary: #745086;
  --onTertiary: #ffffff;
  --tertiaryContainer: #f7d9ff;
  --onTertiaryContainer: #2d0b3e;
  --error: #c1000c;
  --onError: #ffffff;
  --errorContainer: #ffdad4;
  --onErrorContainer: #410001;
  --background: #fdfcff;
  --onBackground: #191c20;
  --surface: #fdfcff;
  --onSurface: #191c20;
  --surfaceVariant: #dce3f2;
  --onSurfaceVariant: #404753;
  --outline: #707784;
  --shadow: #000000;
  --inverseSurface: #2e3035;
  --inverseOnSurface: #eff0f6;
  --inversePrimary: #a3c9ff;
  --surface: #fdfcff;
  --surface1: #f0f3fb;
  --surface2: #e9eff8;
  --surface3: #e2eaf6;
  --surface4: #e0e8f6;
  --surface5: #dbe5f4;
  --gap: 6px;
  --radius: 25px;
  --radius2: 12px;
}
* {
  padding: 0;
  margin: 0;
  border: 0px;
}

body {
  display: flex;
  justify-content: space-around;
  align-items: center;
  height: 100vh;
  margin: 0;
  font-family: "Roboto";
  background-color: var(--surface);
  font-weight: 700;
  flex-direction: column;
}

main {
  flex: 1 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.buttons-area {
  display: flex;
  flex-direction: column;
  width: 400px;
  height: 550px;
  gap: var(--gap);

  border-radius: var(--radius2);
  background-color: var(--surface1);
  padding: 20px;
  flex: 1;
}

.buttons-area > input {
  flex: 1;
}

.numpad {
  display: flex;
  flex-direction: column;
  flex: 4.2;
  gap: var(--gap);
}

.numpad > * {
  display: flex;
  flex: 1;
  gap: var(--gap);
}

button {
  flex: 1;
  border-radius: var(--radius);
  background-color: var(--primaryContainer);
  color: var(--onPrimaryContainer);
  font-weight: 900;
  font-size: 1.2rem;
}

button:hover {
  background-color: var(--tertiaryContainer);
  color: var(--onTertiaryContainer);
  font-size: 1.7rem;
}

.top {
  display: flex;
  flex: 4;
  gap: var(--gap);
}

.bottom {
  display: flex;
  flex: 1;
  gap: var(--gap);
}

.right {
  display: flex;
  flex-direction: column;
  flex: 1;
  gap: var(--gap);
}

.right > * {
  flex: 1;
}

input {
  text-align: right;
  padding: 10px;
  flex: 1;
  background-color: var(--surface);
  color: var(--onSecondaryContainer);
  border-radius: var(--radius2);
  border: 2px solid var(--surface2);
  font-size: 1.5rem;
  margin-bottom: 12px;
}

input:focus-visible {
  outline: none;
  border: 2px solid var(--primary);
}

.zero-division-error {
  color: var(--error);
  font-weight: 900;
}

.input-error {
  border: 2px solid var(--error);
  color: var(--onErrorContainer);
  background-color: var(--errorContainer);
}

.hidden {
  visibility: hidden;
}

a {
  color: var(--onSurfaceVariant);
  text-decoration: none;
}

a:visited {
  color: var(--primary);
}

footer {
  height: 50px;
  font-size: 1.2rem;
}