/* Reset */

*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

h1,
h2,
h3,
h4,
h5,
h6,
p,
ul,
figure,
hr,
blockquote,
a {
  margin: 0;
  padding: 0;
  list-style-type: none;
  text-decoration: none;
}

img {
  max-width: 100%;
}

button {
  border: none;
  background: none;
  outline: none;
}

/* Variables */

:root {
  --main-bg-clr: hsl(222, 26%, 31%);
  --keypad-clr: hsl(223, 31%, 20%);
  --screen-clr: hsl(224, 36%, 15%);
  --delete-btn-clr: hsl(225, 21%, 49%);
  --delete-btn-shadow-clr: hsl(224, 28%, 35%);
  --equal-btn-clr: hsl(6, 63%, 50%);
  --equal-btn-shadow-clr: hsl(6, 70%, 34%);
  --key-clr: hsl(30, 25%, 89%);
  --key-shadow-clr: hsl(28, 16%, 65%);
  --text-clr: hsl(221, 14%, 31%);
  --white-clr: hsl(0, 0%, 100%);
  --fs: 2rem;
  --body-ff: "League Spartan", sans-serif;
}

.light-mode {
  --main-bg-clr: hsl(0, 0%, 90%);
  --keypad-clr: hsl(0, 5%, 81%);
  --screen-clr: hsl(0, 0%, 93%);
  --delete-btn-clr: hsl(185, 42%, 37%);
  --delete-btn-shadow-clr: hsl(185, 58%, 25%);
  --equal-btn-clr: hsl(25, 98%, 40%);
  --equal-btn-shadow-clr: hsl(25, 99%, 27%);
  --key-clr: hsl(45, 7%, 89%);
  --key-shadow-clr: hsl(35, 11%, 61%);
  --text-clr: hsl(60, 10%, 19%);
  --white-clr: hsl(0, 0%, 100%);
}

.purple-mode {
  --main-bg-clr: hsl(268, 75%, 9%);
  --keypad-clr: hsl(268, 71%, 12%);
  --screen-clr: hsl(268, 71%, 12%);
  --delete-btn-clr: hsl(281, 89%, 26%);
  --delete-btn-shadow-clr: hsl(285, 91%, 52%);
  --equal-btn-clr: hsl(176, 100%, 44%);
  --equal-btn-shadow-clr: hsl(177, 92%, 70%);
  --key-clr: hsl(268, 47%, 21%);
  --key-shadow-clr: hsl(290, 70%, 36%);
  --text-clr: hsl(52, 100%, 62%);
  --equal-text-clr: hsl(198, 20%, 13%);
  --white-clr: hsl(0, 0%, 100%);
}

/* Body */

body {
  font-family: var(--body-ff);
  font-size: var(--fs);
  background-color: var(--main-bg-clr);
  font-weight: 700;
}

/* Main */

main {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

/* Calculator */

.calculator {
  max-width: 500px;
  flex: 1;
  margin-inline: 12px;
}

.text {
  color: var(--white-clr);
}

.letter-space,
.theme-number {
  color: var(--white-clr);
  font-size: 1rem;
}

.letter-space {
  letter-spacing: 5px;
  text-transform: uppercase;
}

.theme-number:not(:last-child) {
  margin-right: 5px;
}

.button-wrapper {
  width: 70px;
  height: 30px;
  background-color: var(--screen-clr);
  border-radius: 100vh;
  display: flex;
  position: relative;
}

.button-wrapper.start {
  justify-content: flex-start;
}

.button-wrapper.center {
  justify-content: center;
}

.button-wrapper.end {
  justify-content: flex-end;
}

.theme-btn {
  position: relative;
  flex: 1;
  border-radius: 50%;
  z-index: 2;
}

.indicator {
  display: inline-block;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  margin-inline: 5px;
  background-color: var(--equal-btn-clr);
  transition: 200ms linear;
  position: absolute;
  top: 50%;
  translate: 0 -50%;
}

.screen {
  padding: 32px 24px;
  display: flex;
  justify-content: flex-end;
  background-color: var(--screen-clr);
  border-radius: 10px;
  margin-bottom: 24px;
}

/* Keypad */

.keypad {
  padding: 24px;
  background-color: var(--keypad-clr);
  border-radius: 10px;
}

.grid-container {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.grid-item {
  border-radius: 10px;
  transition: 200ms linear;
  padding-top: 5px;
}

.grid-item:not(:nth-child(4), :nth-child(17), :last-child) {
  background-color: var(--key-clr);
  box-shadow: 0 3px 0 var(--key-shadow-clr);
  color: var(--text-clr);
}

.grid-item:nth-child(4),
.grid-item:nth-child(17) {
  color: var(--white-clr);
  background-color: var(--delete-btn-clr);
  text-transform: uppercase;
  box-shadow: 0 3px 0 var(--delete-btn-shadow-clr);
}

.grid-item:nth-child(17) {
  grid-column: 1 / 3;
}

.grid-item:last-child {
  grid-column: 3 / 5;
  color: var(--white-clr);
  background-color: var(--equal-btn-clr);
  box-shadow: 0 3px 0 var(--equal-btn-shadow-clr);
}

/* Hover States */

.button-wrapper:hover .indicator,
.grid-item:hover {
  filter: brightness(150%);
}

/* Media Queries */

@media all and (max-width: 414px) {
  .grid-container {
    gap: 16px;
  }
}