#background {
  width: 280px;
  height: 380px;
  background: #ecf0f5;
  /*-webkit-animation: bgChange 2s 2s alternate infinite;*/
  /*transition: all 2s ease;*/
}

#result {
  display: block;
  font-family: sans-serif;
  width: 230px;
  height: 45px;
  margin: 10px auto;
  text-align: right;
  border: 0;
  background: #3b3535;
  color: #fff;
  padding: 20px 0px 5px 0px;
  font-size: 20px;
  margin: 0px 0px 10px 25px;
  outline: none;
  overflow: hidden;
  /*letter-spacing: 1px;*/
  position: relative;
  top: 10px;
}

#result:hover {
  cursor: text;
}

#first-rows {
  margin-bottom: 20px;
  position: relative;
  top: 10px;
}

.rows {
  width: 300px;
  margin-top: 10px;
}

#delete {
  width: 110px;
  height: 50px;
  margin-left: 25px;
  border-radius: 4px;
}


/* Aligning the division and dot button properly */

.fall-back {
  margin-left: 3px !important;
}


/* Aligning the addition and equals to button properly */

.align {
  margin-left: 6px !important;
}


/* Button styling */

.btn-style {
  width: 50px;
  height: 50px;
  margin-left: 5px;
  border-radius: 4px;
}

.eqn {
  width: 50px;
  height: 50px;
  margin-left: 5px;
  border-radius: 4px;
}

.first-child {
  margin-left: 25px;
}



/* Adding background color to the number values */

.num-bg {
  background: #000;
  color: #fff;
  font-size: 26px;
  cursor: pointer;
  outline: none;
  border-bottom: 3px solid #333;
}

.num-bg:active {
  background: #000;
  color: #fff;
  font-size: 26px;
  cursor: pointer;
  outline: none;
  box-shadow: inset 5px 5px 5px #555;
}


/*Adding background color to the operator values */

.opera-bg {
  background: #333;
  color: #fff;
  font-size: 26px;
  cursor: pointer;
  outline: none;
  border-bottom: 3px solid #555;
}

.opera-bg:active {
  background: #333;
  color: #fff;
  font-size: 26px;
  cursor: pointer;
  outline: none;
  box-shadow: inset 4px 4px 4px #555;
}


/*Adding a background color to the delete button */

.del-bg {
  background: #24b4de;
  color: #fff;
  font-size: 26px;
  cursor: pointer;
  outline: none;
  border-bottom: 3px solid #399cb9;
}

.del-bg:active {
  background: #24b4de;
  color: #fff;
  font-size: 26px;
  cursor: pointer;
  outline: none;
  box-shadow: inset 4px 4px 4px #399cb9;
}


/*Adding a background color to the equals to button */

#eqn-bg {
  background: #17a928;
  color: #fff;
  font-size: 26px;
  cursor: pointer;
  outline: none;
  border-bottom: 3px solid #1f7a29;
}

#eqn-bg:active {
  background: #17a928;
  color: #fff;
  font-size: 26px;
  cursor: pointer;
  outline: none;
  box-shadow: inset 4px 4px 4px #1f7a29;
}

@-webkit-keyframes bgChange {
  0% {
    background: #24b4de;
  }

  50% {
    background: #17a928;
  }

  100% {
    background: #399cb9;
  }
}