/* attribution css*/
.attribution {
    font-size: 11px;
    text-align: center;
    color: var(--attribution-color);
  }
  .attribution a {
    color: var(--key-color-secondary);
  }
  
  *,
  *::before,
  *::after {
    box-sizing: border-box;
  }
  
  body,
  h1,
  h2,
  h3,
  h4,
  p,
  figure,
  blockquote,
  dl,
  dd {
    margin: 0;
  }
  
  ul[role="list"],
  ol[role="list"] {
    list-style: none;
  }
  
  html:focus-within {
    scroll-behavior: smooth;
  }
  
  body {
    min-height: 100vh;
    text-rendering: optimizeSpeed;
    line-height: 1.5;
  }
  
  a:not([class]) {
    text-decoration-skip-ink: auto;
  }
  
  img,
  picture {
    max-width: 100%;
    display: block;
  }
  
  input,
  button,
  textarea,
  select {
    font: inherit;
  }
  
  @media (prefers-reduced-motion: reduce) {
    html:focus-within {
      scroll-behavior: auto;
    }
  
    *,
    *::before,
    *::after {
      animation-duration: 0.01ms !important;
      animation-iteration-count: 1 !important;
      transition-duration: 0.01ms !important;
      scroll-behavior: auto !important;
    }
  }
  
  :root {
    --fs-default: minmax(1rem, 2rem);
    --fs-12: 0.75rem;
  
    --fs-20: minmax(1rem, 1.25rem);
  
    --fw-default: 700;
  
    --padding-24: 1.5rem;
    --padding-32: 2rem;
  
    --border-radius: 7px;
  }
  .theme-1 {
    --main-bg: hsl(222, 26%, 31%);
    --keypad-bg: hsl(223, 31%, 20%);
    --screen-bg: hsl(224, 36%, 15%);
  
    --key-color-main: hsl(225, 21%, 49%);
    --key-color-main-shadow: hsl(224, 28%, 35%);
    --key-color-secondary: hsl(6, 63%, 50%);
    --key-color-secondary-shadow: hsl(6, 70%, 34%);
    --key-color-tertiary: hsl(30, 25%, 89%);
    --key-color-teritary-shadow: hsl(28, 16%, 65%);
  
    --text-numbers: hsl(221, 14%, 31%);
    --text-letters: #ffffff;
    --text-equal: #ffffff;
  
    --attribution-color: hsl(30, 25%, 89%);
  }
  .theme-2 {
    --main-bg: hsl(0, 0%, 90%);
    --keypad-bg: hsl(0, 5%, 81%);
    --screen-bg: hsl(0, 0%, 93%);
  
    --key-color-main: hsl(185, 42%, 37%);
    --key-color-main-shadow: hsl(185, 58%, 25%);
    --key-color-secondary: hsl(25, 98%, 40%);
    --key-color-secondary-shadow: hsl(25, 99%, 27%);
    --key-color-tertiary: hsl(45, 7%, 89%);
    --key-color-teritary-shadow: hsl(35, 11%, 61%);
  
    --text-numbers: hsl(60, 10%, 19%);
    --text-letters: hsl(60, 10%, 19%);
    --text-equal: #ffffff;
  
    --attribution-color: hsl(185, 58%, 25%);
  }
  .theme-3 {
    --main-bg: hsl(268, 75%, 9%);
    --keypad-bg: hsl(268, 71%, 12%);
    --screen-bg: hsl(268, 71%, 12%);
  
    --key-color-main: hsl(281, 89%, 26%);
    --key-color-main-shadow: hsl(285, 91%, 52%);
    --key-color-secondary: hsl(176, 100%, 44%);
    --key-color-secondary-shadow: hsl(177, 92%, 70%);
    --key-color-tertiary: hsl(268, 47%, 21%);
    --key-color-teritary-shadow: hsl(290, 70%, 36%);
  
    --text-numbers: hsl(52, 100%, 62%);
    --text-letters: hsl(52, 100%, 62%);
    --text-equal: hsl(52, 100%, 62%);
  
    --attribution-color: hsl(52, 100%, 62%);
  }
  body {
    /* just for display*/
    font-family: "Spartan", sans-serif;
    font-size: var(--fs-default);
    font-weight: var(--fw-default);
  
    display: grid;
    place-items: center;
    background-color: var(--main-bg);
    text-align: center;
  }
  
  .main {
    width: 87%;
    max-width: 540px;
  }
  .header {
    color: var(--text-letters);
  }
  .screen {
    background-color: var(--screen-bg);
    text-align: right;
    padding: var(--padding-24) var(--padding-32);
    border-radius: var(--border-radius);
    color: var(--text-letters);
  }
  .keyboard {
    display: grid;
    grid-auto-rows: 60px;
    grid-auto-columns: minmax(60px, 100px);
    gap: 0.8125rem;
    color: var(--text-numbers);
    background-color: var(--keypad-bg);
    margin-top: 1.5em;
    justify-content: space-between;
  }
  .button {
    background-color: var(--key-color-tertiary);
    border: none;
    transition: all 0.2s ease;
    padding: 0.75em;
    box-shadow: inset 0px -2px 0px var(--key-color-teritary-shadow);
    cursor: pointer;
    color: var(--text-numbers);
  }
  .slider-container {
    display: flex;
    justify-content: flex-end;
    align-items: center;
    gap: 1.3125rem;
  }
  .theme-radio {
    cursor: pointer;
    display: none;
  }
  .theme-slider {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: space-around;
    width: 4.5rem;
    height: 2rem;
  }
  .theme-slider::before {
    content: " ";
    position: absolute;
    left: 0;
    z-index: -1;
    width: 100%;
    height: 80%;
    background-color: var(--screen-bg);
    border-radius: 13px;
  }
  .theme-label {
    position: relative;
    top: -75%;
    pointer-events: none;
    cursor: pointer;
  }
  .theme-indicator {
    background-color: var(--key-color-secondary);
    position: absolute;
  
    left: 0; /*4% 37%  74%*/
    width: 1rem;
    height: 1rem;
    border-radius: 50%;
    transition: transform 200ms ease;
    cursor: pointer;
  }
  .theme-slider input[id="1"]:checked ~ .theme-indicator {
    transform: translateX(0.25rem);
  }
  .theme-slider input[id="2"]:checked ~ .theme-indicator {
    transform: translateX(1.65rem);
  }
  .theme-slider input[id="3"]:checked ~ .theme-indicator {
    transform: translateX(3.25rem);
  }

/* utilities*/
  .flex-row {
    display: flex;
  }
  .border-radius {
    border-radius: var(--border-radius);
  }
  .flex-space-between {
    justify-content: space-between;
  }
  .padding-24 {
    padding: var(--padding-24);
  }
  .padding-bottom-32 {
    padding-bottom: var(--padding-32);
  }
  .font-size-default {
    font-size: var(--fs-default);
  }
  .font-size-12 {
    font-size: var(--fs-12);
  }
  .font-size-20 {
    font-size: var(--fs-20);
  }
  
  .text-letters {
    color: var(--text-letters);
    background-color: var(--key-color-main);
    box-shadow: inset 0px -2px 0px var(--key-color-main-shadow);
  }
  .text-equal {
    color: var(--text-equal);
    background-color: var(--key-color-secondary);
    box-shadow: inset 0px -2px 0px var(--key-color-secondary-shadow);
  }
  .button:hover,
  .button:active {
    filter: brightness(1.2);
  }
  
/* exceptions */
  .grid-reset {
    grid-area: 5 / 1 / 6 / 3;
  }
  .grid-equal {
    grid-area: 5 / 3 / 6 / 5;
  }