style.css

@import url('https://fonts.googleapis.com/css2?family=Poppins&display=swap');
body {
  font-family: 'Poppins', sans-serif;
  margin: 0;
  overflow: hidden;
  background-color: rgb(40, 40, 40); /* #ify42-added background color */
}
.heading {
  background-color: rgb(40, 40, 40);
  color: aliceblue;
  font-size: 40px;
  position: absolute;
  top: 25px;
  font-family: 'Poppins', sans-serif;
  font-weight: 700;
  left: 5%;
  /* display: flex;
    justify-content: center;
    align-items: start;      */
}

table {
  width: 100%;
  height: 70vh;
  position: absolute; /* ify42-added postion and bottom to fix the table to the bottom */
  bottom: 0;
  background-color: rgb(25, 25, 25);
  color: white;
  font-family: 'Montserrat', sans-serif;
}

td {
  width: 20%; /** width: 25% **/
  text-align: center;
  font-size: 24px;
  background-color: rgb(20, 20, 20);
}

td:hover {
  background-color: rgb(30, 30, 30);
  cursor: pointer;
}

#previousExpression {
  height: 10%;
  background-color: transparent;
  color: grey;
  font-size: 18px;
  display: flex;
  justify-content: flex-end;
  align-items: flex-end;
  padding: 2%;
  box-sizing: border-box;
  position: absolute;
  top: 8%;
  width: 100%;
}

#resultArea {
  height: 30vh;
  background-color: rgb(40, 40, 40);
  color: white;
  display: flex;
  justify-content: flex-end;
  align-items: flex-end;
  padding: 4%;
  box-sizing: border-box;
}

/* added the result css to make it break and reduce - ify47 */
#result {
  font-size: 20px;
  word-wrap: break-word;
  height: 50%;
}

#result::-webkit-scrollbar,
#previousExpression::-webkit-scrollbar {
  display: none;
}

#equalsign {
  background-color: rgb(209, 81, 21);
}

#equalsign:hover {
  background-color: rgb(196, 106, 67);
}

#clrButton {
  /**height: 10%;**/
  text-align: center;
  font-size: 24px;
  border: none;
  color: white;
}

.operators {
  background-color: rgb(209, 81, 21);
}

.operators:hover {
  background-color: rgb(196, 106, 67);
}
* {
  box-sizing: border-box;
}
:root {
  --orange: rgb(209, 81, 21);
  --slate1: rgb(20, 20, 20);
  --slate2: rgb(30, 30, 30);
  --white: #f9f5f6;
  /* --red: #F31559;
    --magenta: #FF52A2;
    --orange: #FFB07F;

    --green: #1A5D1A;
    
    --blue: #78C1F3; */
}

@keyframes background-pan {
  from {
    background-position: 0% center;
  }

  to {
    background-position: -200% center;
  }
}

@keyframes scale {
  from,
  to {
    transform: scale(0);
  }

  50% {
    transform: scale(1);
  }
}

@keyframes rotate {
  from {
    transform: rotate(0deg);
  }

  to {
    transform: rotate(180deg);
  }
}

div {
  color: white;
  font-family: 'Rubik', sans-serif;
  font-size: clamp(2em, 2vw, 4em);
  font-weight: 400;
}

div > .magic {
  display: inline-block;
  position: relative;
}

div > .magic > .magic-text {
  animation: background-pan 3s linear infinite;
  background: linear-gradient(
    to right,
    var(--orange),
    var(--white),
    /* var(--slate2), */ var(--white),
    var(--orange)
  );
  background-size: 200%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  white-space: nowrap;
}

@media (max-width: 481px) {
  table {
    height: 57vh; /* ify42-added height for smaller devices so it can be responsive */
  }

  /* made scrolling responsive for smaller devices- ify47 */
  #result {
    width: 100%;
    height: 100px;
  }

  .resultCalc {
    word-break: break-all;
    word-wrap: break-word;
    float: right;
  }

  #resultArea {
    margin-top: 50px;
    width: 100%;
  }

  #previousExpression {
    height: 9%;
    display: block;
    word-wrap: break-word;
    overflow: scroll;
    top: 12%;
    direction: rtl;
  }
}