/* test scale feature */
 html {
  transform: scale(1.5);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'League Spartan', sans-serif;
}

body {
  background-color: hsl(222, 26%, 31%);
  font-size: 16px;
  margin-top: 100px;
  color: white;  
  overflow: hidden;
}

.theme-numbers {
  text-align: end;
  margin-right: 5px;
  margin-bottom: -3px;
  letter-spacing: 1.5ch;
}

.upper-container {
  display: flex;
  justify-content: space-between;
  margin: 5px;
  align-items: center;
}

.calc {
  flex-basis: 60%;
}

.calculator {
  margin: auto;
  border-radius: 5px;
  padding: 50px;
  width: 302px;
}

h4 {
  margin-top: 4px;
  font-size: 0.4rem;
}

.result {
  margin-bottom: 10px;
  width: 200px;
  border: none;
  text-align: right;
  font-size: 24px;
  background-color: hsl(224, 36%, 15%);
  padding: 10px;
  border-radius: 5px;
}

.buttons {
  display: grid;
  padding: 15px;
  width: 200px;
  height: 250px;
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: repeat(5, 1fr);
  grid-gap: 7px;
  border-radius: 5px;
  background-color: hsl(223, 31%, 20%);
}

.btn {
  color: #323f61;
  font-size: 1.3rem;
  background-color: hsl(30, 25%, 89%);
  border: none;
  border-bottom: 3px solid hsl(28, 16%, 65%);
  border-radius: 3px;
  cursor: pointer;
  padding-top: 4px;
}

.btn.clear {
  /* row-start, column start, row end , columd end */
  grid-area: 5 / 1 / 5 / 3;
}

.btn.calculate {
  grid-area: 5 / 3 / 5 / 5;
  font-size: 0.8rem;
  background-color: hsl(6, 63%, 50%);
  border-bottom: 2px solid hsl(6, 70%, 34%);
}

.btn.delete,
.btn.clear {
  color: white;
  background-color: hsl(225, 21%, 49%);
  border-bottom: 2px solid hsl(222, 26%, 31%);
  font-size: 0.7rem;
}

.btn:hover {
  background-color: rgb(226, 208, 188);
}

.btn.delete:hover,
.btn.clear:hover {
  background-color: #2d3958;
}

.btn.calculate:hover {
  background-color: #c22311;
}

/* theme toggle */
.tri-state-toggle input {
  margin: 3px;
  height: 10px;
  width: 10px;
  appearance: none;
  background-color: hsl(6, 63%, 50%);
  border-radius: 50%;
  opacity: 0;
}

.tri-state-toggle input:hover {
  cursor: pointer;
}

.tri-state-toggle {
  height: 16px;
  width: 48px;
  display: flex;
  justify-content: baseline;
  background-color: hsl(223, 31%, 20%);
  border-radius: 10px;
}

#one {
  opacity: 1;
}
input:disabled {
  -webkit-text-fill-color: currentColor;
  opacity: 1;
}

/* responsive design */

@media (min-width: 576px) {
  .calculator {
    width: 400px;
  }

  .buttons {
    width: 300px;
  }

  .result {
    width: 300px;
  }

  .calc {
    flex-basis: 70%;
  }

}