main {
  height: 100dvh;
  display: flex;
  justify-content: center;
}

main > div {
  height: 100%;
  background: none;
  color: white;
  width: 100%;
  padding: 40px 0;
  display: flex;
  align-items: center;
  gap: 20px;
  flex-direction: column;
}

main > div > h1 {
  color: #f7931e;
  font-size: 2.5rem;
}

#calc-box {
  position: relative;
  background: rgba(255, 255, 255, 0.1);
  border: 2px solid #fff;
  border-radius: 20px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

h1 {
  text-align: center;
  font-weight: 400;
  color: #000;
}

#result-display {
  margin: auto;
  position: relative;
  width: 100%;
  height: 100px;
  margin-bottom: 20px;
  border-radius: 20px;
  border-bottom-right-radius: 10px;
  border-bottom-left-radius: 10px;
  background-color: #fff;
  overflow: hidden;
}

#result-display > div {
  display: flex;
  justify-content: right;
  align-items: center;
  padding-right: 15px;
  color: #000;
}

#topRBox,
#bottomRBox {
  height: 50%;
  font-size: 30px;
}

#topRBox p,
#bottomRBox p {
  color: #000;
}

#topRBox {
  border-bottom: 1px solid gray;
}

#number-set > button {
  font-size: 30px;
  padding: 5px;
  width: 70px;
  height: 70px;
  text-align: center;
  color: white;
  background: rgba(255, 255, 255, 0.1);
  border: none;
  border-radius: 50%;
}

#number-set > button:hover {
  background-color: #fff;
  color: #f7931e;
}

#number-set > .diff-theme {
  color: #f7931e;
  background: #262626;
}

#number-set > .diff-theme:hover {
  background-color: #f7931e;
  color: #262626;
}

#number-set > #clear {
  width: auto;
  border-radius: 30px;
  grid-column: 1/3;
}

#number-set {
  width: fit-content;
  margin: auto;
  display: grid;
  gap: 15px;
  grid-template-columns: repeat(5, 1fr);
}

#number-set > #equals-to {
  height: auto;
  border-radius: 30px;
  grid-row: 4/6;
  grid-column: 5/6;
}

#number-set > #zero {
  width: auto;
  border-radius: 30px;
  grid-column: 2/4;
}

/*-------------For phones and small mobile devices section--------------*/

@media screen and (max-width: 768px) {
  main > div {
    justify-content: center;
  }

  #calc-box {
    width: 93%;
  }

  #number-set {
    gap: 15px;
    margin: 0;
    width: 100%;
  }

  #number-set > button {
    width: 100%;
    height: 60px;
  }
}