:root,
.main-theme {
  --main-background: hsl(222, 26%, 31%);
  --background-second: hsl(223, 31%, 20%);
  --background-third: hsl(224, 36%, 15%);
  --key-background: hsl(225, 21%, 49%);
  --key-shadow: hsl(224, 28%, 35%);
  --key-background-toggle: hsl(6, 63%, 50%);
  --key-shadow-toggle: hsl(6, 70%, 34%);
  --key-background-second: hsl(30, 25%, 89%);
  --key-shadow-second: hsl(28, 16%, 65%);
  --text: hsl(221, 14%, 31%);
  --text-second: hsl(0, 0%, 100%);
}

.light-theme {
  --main-background: hsl(0, 0%, 90%);
  --background-second: hsl(0, 5%, 81%);
  --background-third: hsl(0, 0%, 93%);
  --key-background: hsl(185, 42%, 37%);
  --key-shadow: hsl(185, 58%, 25%);
  --key-background-toggle: hsl(25, 98%, 40%);
  --key-shadow-toggle: hsl(25, 99%, 27%);
  --key-background-second: hsl(45, 7%, 89%);
  --key-shadow-second: hsl(35, 11%, 61%);
  --text: hsl(60, 10%, 19%);
  --text-second: hsl(0, 0%, 100%);
}

.dark-theme {
  --main-background: hsl(268, 75%, 9%);
  --background-second: hsl(268, 71%, 12%);
  --background-third: hsl(281, 89%, 26%);
  --key-background: hsl(285, 91%, 52%);
  --key-shadow: hsl(176, 100%, 44%);
  --key-background-toggle: hsl(177, 92%, 70%);
  --key-shadow-toggle: hsl(268, 47%, 21%);
  --key-background-second: hsl(290, 70%, 36%);
  --key-shadow-second: hsl(52, 100%, 62%);
  --text: hsl(198, 20%, 13%);
  --text-second: hsl(0, 0%, 100%);
}
html {
  font: 32px "League Spartan", sans-serif;
}

body {
  margin: 0;
  padding: 0;
  display: flex;
}

main {
  flex: 1;
  background-color: var(--main-background);
  color: var(--text-second);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.calculator {
  background-color: var(--main-background);
  display: flex;
  min-width: 340px;
  max-width: 80rem;
  flex-direction: column;
  user-select: none;
  padding: 1rem 0;
}

.calculator__header {
  flex: 1;
  width: 100%;
  display: flex;
}

.header__logo {
  flex: 1;
  font-size: 1.2rem;
}

.header__theme-selector {
  display: grid;
  grid-template: repeat(2, auto) / 4fr repeat(3, 1fr);
  place-items: center center;
  flex: 1;
}

.header__theme-selector > div {
  flex: 1;
}
.theme-selector__number {
  font-size: 0.4rem;
  padding-bottom: 0.2rem;
  cursor: pointer;
}

.theme-selector__text {
  font-size: 0.5rem;
  text-transform: uppercase;
}

.theme-selector__switch {
  grid-column: 2 / 5;
  height: 0.9rem;
  padding: 0 0.2rem;
  background: var(--background-second);
  border-radius: 0.5rem;
  place-self: center stretch;
  cursor: pointer;
  position: relative;
}

.theme-selector__circle {
  position: absolute;
  transition: all 300ms;
  top: 0.2rem;
  height: 0.5rem;
  width: 0.5rem;
  background: var(--key-background-toggle);
  border-radius: 0.5rem;
}

.theme-selector__circle.main-theme {
  transform: translateX(0%);
}

.theme-selector__circle.light-theme {
  transform: translateX(0.85rem);
}

.theme-selector__circle.dark-theme {
  transform: translateX(1.7rem);
}

.calculator__screen {
  margin-top: 0.8rem;
  padding: 0.7rem;
  text-align: right;
  font-size: 2rem;
  border-radius: 0.5rem;
  background: var(--background-third);

  word-wrap: normal;
  max-width: 100%;
}

.calculator__controlpad {
  margin: 1rem 0;
  padding: 0.8rem;
  font-size: 1.2rem;
  border-radius: 0.5rem;
  background: var(--background-second);
  display: grid;
  grid-template: repeat(5, 1fr) / repeat(4, 1fr);
  place-self: stretch stretch;
  gap: 0.5rem;
}

.calculator__controlpad > div {
  padding: 0.3rem 0.6rem 0.1rem;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--key-background-second);
  color: var(--text);
  box-shadow: 0 5px 0px var(--key-shadow-second);
  border-radius: 6px;
  cursor: pointer;
}

.calculator__controlpad > div:hover {
  filter: brightness(110%);
}

.calculator__controlpad > div.button:active {
  transform: translateY(2px);
}

.calculator__controlpad > .button.reset,
.calculator__controlpad > .button.equal,
.calculator__controlpad > .button.del {
  font-size: 0.7rem;
  background: var(--key-background);
  color: var(--text-second);
  box-shadow: 0 5px 0px var(--key-shadow);
}

.calculator__controlpad > .button.reset {
  grid-column: 1 / 3;
  aspect-ratio: auto;
}

.calculator__controlpad > .button.equal {
  grid-column: 3 / 5;
  aspect-ratio: auto;
  background: var(--key-background-toggle);
  box-shadow: 0 5px 0px var(--key-shadow-toggle);
}

@media only screen and (max-width: 450px) {
  .calculator__controlpad > div {
    padding: 0;
    aspect-ratio: 1;
  }
}

@media (prefers-color-scheme: light) {
  :root {
    --main-background: hsl(0, 0%, 90%);
    --background-second: hsl(0, 5%, 81%);
    --background-third: hsl(0, 0%, 93%);
    --key-background: hsl(185, 42%, 37%);
    --key-shadow: hsl(185, 58%, 25%);
    --key-background-toggle: hsl(25, 98%, 40%);
    --key-shadow-toggle: hsl(25, 99%, 27%);
    --key-background-second: hsl(45, 7%, 89%);
    --key-shadow-second: hsl(35, 11%, 61%);
    --text: hsl(60, 10%, 19%);
    --text-second: hsl(0, 0%, 100%);
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --main-background: hsl(222, 26%, 31%);
    --background-second: hsl(223, 31%, 20%);
    --background-third: hsl(224, 36%, 15%);
    --key-background: hsl(225, 21%, 49%);
    --key-shadow: hsl(224, 28%, 35%);
    --key-background-toggle: hsl(6, 63%, 50%);
    --key-shadow-toggle: hsl(6, 70%, 34%);
    --key-background-second: hsl(30, 25%, 89%);
    --key-shadow-second: hsl(28, 16%, 65%);
    --text: hsl(221, 14%, 31%);
    --text-second: hsl(0, 0%, 100%);
  }
}