* {
  padding: 0;
  margin: 0;
  box-sizing: inherit;
}

html {
  /* 10 / 16 = 0.625 x 100 = 62.5% */
  /* font-size: 62.5%; */
  /* for readable rem and em conversion */
  font-size: calc(10 / 16 * 100%);
  box-sizing: border-box;
}

body {
  font-family: "Space Mono", monospace;
  /* color: ; */
  height: 100vh;
  background-color: hsl(185, 41%, 84%);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.header {
  /* margin-bottom: 9.6rem; */
  /* transform was used so it would not interfere with the main content's space */
  margin-bottom: 4.4rem;
}

.main {
  width: 90rem;
  font-size: 1.6rem;
  background-color: hsl(0, 100%, 100%);
  padding: 3.6rem;
  border-radius: 1.1rem;
}

.main-content {
  display: grid;
  grid-template-columns: 45fr 55fr;
}

.calculate-container {
  display: flex;
  flex-direction: column;
  justify-content: space-around;
  gap: 3.6rem;
}

.label-container {
  display: flex;
  justify-content: space-between;
  color: hsl(183, 100%, 15%);
}

.header-primary {
  font-size: 3.2rem;
  letter-spacing: 0.6rem;
  color: hsl(186, 14%, 43%);
}

.grid {
  display: grid;
}

.grid--3-cols {
  grid-template-columns: repeat(3, 1fr);
}

.label {
  display: block;
  margin-bottom: 1rem;
}

.warning {
  font-weight: 600;
  color: #fd7e14;
}

.hidden {
  display: none;
}

.display-container {
  display: flex;
  flex-direction: column;
  background-color: hsl(183, 100%, 15%);
  border-radius: 1.2rem;
  padding: 4.4rem 3.6rem;
}

.display-content {
  display: flex;
  flex-direction: column;
  gap: 2.6rem;
}

.display--flex {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.display-text {
  font-weight: 600;
  color: hsl(189, 47%, 97%);
}

.display-subtext {
  color: hsl(186, 14%, 43%);
}

.amount {
  font-size: 4.4rem;
  font-weight: 600;
  color: hsl(172, 67%, 45%);
}

.input {
  font-family: inherit;
  font-weight: 600;
  width: 100%;
  padding: 1.2rem 1.6rem;
  text-align: right;
  font-size: 2rem;
  border: none;
  background-color: #f4f4f4;
  color: hsl(183, 100%, 15%);
  border-radius: 0.6rem;
  position: relative;
  cursor: pointer;
}

.input:focus,
.btn--custom:focus {
  outline: 2px solid hsl(172, 67%, 45%);
}

.input::placeholder {
  color: #a7a7a7;
}

.rel-position {
  position: relative;
}

.label-custom {
  font-family: inherit;
  font-size: 2rem;
  font-weight: 600;
  color: #a7a7a7;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  cursor: pointer;
  pointer-events: none;
}

.icon-svg {
  position: absolute;
  top: 50%;
  left: 4%;
  transform: translate(0, -50%);
}

.btn {
  font-family: inherit;
  font-size: 2rem;
  font-weight: 600;
  padding: 1rem 2rem;
  border: none;
  background-color: hsl(183, 100%, 15%);
  color: hsl(189, 47%, 97%);
  border-radius: 0.6rem;
  cursor: pointer;
}

.btn--reset {
  margin-top: auto;
  color: hsl(183, 100%, 15%);
  background-color: hsl(172, 67%, 45%);
}

.btn--custom {
  width: 100%;
  padding: 1.2rem 1.2rem;
  background-color: #f4f4f4 !important;
  color: hsl(183, 100%, 15%);
  text-align: right;
}

.btn--active {
  background-color: hsl(185, 41%, 84%);
  color: hsl(183, 100%, 15%);
}

.btn--default {
  cursor: not-allowed;
  color: hsla(183, 100%, 15%, 0.353);
  background-color: hsla(172, 67%, 45%, 0.264);
}

/***************************************/
/* Helper classes */
/***************************************/

.grid--gap-md {
  gap: 4.4rem;
}

.grid--gap-sm {
  gap: 1.2rem;
}

/***************************************/
/* Media Queries */
/***************************************/

/* 59 * 16 = 944 px */

@media (max-width: 59em) {
  html {
    height: 100%;
  }
  html {
    font-size: calc(8 / 16 * 100%);
  }
}

/* 46 * 16 = 736 px */

@media (max-width: 46em) {
  .main {
    width: 65rem;
  }
  .main-content {
    display: grid;
    grid-template-columns: 1fr;
  }

  .btn {
    font-size: 2.6rem;
    padding: 1.6rem 2.4rem;
  }

  .label-custom {
    font-size: 3.2rem;
  }
}

/* 34 * 16 = 544 px */

@media (max-width: 34em) {
  html {
    font-size: calc(7 / 16 * 100%);
  }

  body {
    height: 100%;
    justify-content: space-around;
    gap: 6.2rem;
  }

  .main {
    width: 100%;
    margin-top: auto;
    padding: 7.2rem 5.2rem;
    border-radius: 2.4rem 2.4rem 0 0;
  }

  .header {
    transform: none;
    margin-top: 12rem;
  }

  .amount {
    font-size: 3.6rem;
  }

  .grid--3-cols {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.8rem;
  }

  .grid--gap-md {
    gap: 5.2rem;
  }

  .main-content {
    display: grid;
    grid-template-columns: 1fr;
  }

  .btn--reset {
    margin-bottom: auto;
  }

  .display-container {
    gap: 4.2rem;
    padding: 5.2 4.4rem;
  }

  .calculate-container {
    gap: 2.6rem;
  }

  .display-content {
    gap: 1.8rem;
  }
}