*, *::before, *::after {
  box-sizing: border-box;
  font-family: Gotham Rounded, sans-serif;
  font-weight: normal;
  --color-1: rgb(255, 0, 0);
  --color-2: rgb(255, 166, 0);
  --color-3: rgb(238, 255, 0);
  --color-4: rgb(30, 255, 0);
  --color-5: rgb(0, 255, 255);
  --color-6: rgb(4, 0, 255);
  --color-7: rgb(140, 0, 255);
  --color-8: rgb(255, 0, 170);
  --bg-color-1: rgba(255, 255, 255, .60);
  --bg-color-2: rgba(255, 255, 255, .75);
  --bg-color-3: rgba(255, 255, 255, .90);
}

body {
  padding: 0;
  margin: 0;
  background-color: var(--color-1);
  animation: change 80s infinite;
}

@keyframes change {
  0% {
      background-color: var(--color-1);
  }
  12.5% {
      background-color: var(--color-2);
  }
  25% {
      background-color: var(--color-3);
  }
  37.5% {
      background-color: var(--color-4);
  }
  50% {
      background-color: var(--color-5);
  }
  62.5% {
      background-color: var(--color-6);
  }
  75% {
      background-color: var(--color-7);
  }
  87.5% {
      background-color: var(--color-8);
  }
  100% {
      background-color: var(--color-1);
  }
}

nav {
  height: 1rem;
}

@media screen and (max-width: 1000px) {
  nav {
      height: 3rem;
  }
}

.calculator-grid {
  display: grid;
  padding: 0.3rem;
  min-height: fit-content;
  min-width: fit-content;
  justify-content: center;
  grid-template-columns: repeat(4, 90px);
  grid-template-rows: minmax(120px, auto) repeat(5, 90px);
  border: 2px solid rgba(0, 0, 0, 0.5); /* Added border */
  border-radius: 10px; /* Rounded corners for the calculator */
  background-color: rgba(255, 255, 255, 0.2); /* Slight background color for visibility */
}

.calculator-grid > button {
  cursor: pointer;
  font-size: 2rem;
  outline: none;
  border: none;
  border: 2px solid rgba(0, 0, 0, 0.5);
  border-radius: 5px;
  margin: 0.15rem;
  background-color: var(--bg-color-2);
  transition: background-color 0.3s, transform 0.3s; /* Transition for smooth effect */
}

.calculator-grid > button:hover {
  background-color: var(--bg-color-3);
  transform: scale(1.1); /* Increase size by 10% */
}

.calculator-grid > button:active {
  background-color: var(--bg-color-1);
}

.span-two {
  grid-column: span 2;
}

.output {
  grid-column: 1 / -1;
  margin: 0.15rem;
  border-radius: 5px;
  background-color: rgba(0, 0, 0, .5);
  display: flex;
  align-items: flex-end;
  justify-content: space-around;
  flex-direction: column;
  padding: 10px;
  word-wrap: break-word;
  word-break: break-all;
}

.output #mini-display {
  color: rgba(255, 255, 255, .75);
  font-size: 1.5rem;
}

.output #main-display {
  color: white;
  font-size: 2.5rem;
}

/* Added copyright section */
.footer {
  grid-column: 1 / -1;
  text-align: center;
  color: rgba(255, 255, 255, 0.8);
  margin-top: 10px;
  font-size: 0.8rem;
}

/* Add styles for copyright */
.copyright {
  padding: 20px;
  font-style: italic;
  font-weight: 400;
  font-size:1.5rem;
  color: rgb(0, 0, 0);
}