@import url('https://fonts.googleapis.com/css2?family=Cousine:ital,wght@0,400;0,700;1,400;1,700&display=swap');

:root {
  --text-color: rgb(0, 221, 255);
  --text-color-error: rgb(255, 38, 0);
  --number-size: 1.7rem;
}

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

body {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  width: 100%;
  overflow: auto;
  background-color: #111;
  font-family: 'Cousine', monospace;
  font-weight: 700;
}

.container {
  display: grid;
  width: min-content;
  background-color: #202020;
  color: var(--text-color);
  text-shadow: 0px 0px 7px var(--text-color);
  padding: 10px;
  border-radius: 10px;
  gap: 7px;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  grid-template-areas:
    'screen screen screen screen'
    'low-screen low-screen low-screen low-screen'
    'AC AC DEL MLT'
    'SEVEN EIGHT NINE DIV'
    'FOUR FIVE SIX SUB'
    'ONE TWO THREE ADD'
    'ZERO ZERO PER CALC';
}

button {
  background-color: #3b3b3b;
  color: inherit;
  border: none;
  border-radius: 5px;
  font-size: 1.2rem;
  text-shadow: inherit;
  transition: 300ms ease;
  cursor: pointer;
  min-width: 5rem;
  height: 5rem;
}

button:hover {
  background-color: #444;
}

button[data-action='DEL'] {
  grid-area: DEL;
}
button[data-action='AC'] {
  grid-area: AC;
}
button[data-number='1'] {
  grid-area: ONE;
  font-size: var(--number-size);
}
button[data-number='2'] {
  grid-area: TWO;
  font-size: var(--number-size);
}
button[data-number='3'] {
  grid-area: THREE;
  font-size: var(--number-size);
}
button[data-number='4'] {
  grid-area: FOUR;
  font-size: var(--number-size);
}
button[data-number='5'] {
  grid-area: FIVE;
  font-size: var(--number-size);
}
button[data-number='6'] {
  grid-area: SIX;
  font-size: var(--number-size);
}
button[data-number='7'] {
  grid-area: SEVEN;
  font-size: var(--number-size);
}
button[data-number='8'] {
  grid-area: EIGHT;
  font-size: var(--number-size);
}
button[data-number='9'] {
  grid-area: NINE;
  font-size: var(--number-size);
}
button[data-number='0'] {
  grid-area: ZERO;
  font-size: var(--number-size);
}
button[data-number='.'] {
  grid-area: PER;
  font-size: var(--number-size);
}
button[data-operator='*'] {
  grid-area: MLT;
  font-size: var(--number-size);
}
button[data-operator='/'] {
  grid-area: DIV;
  font-size: var(--number-size);
}
button[data-operator='-'] {
  grid-area: SUB;
  font-size: var(--number-size);
}
button[data-operator='+'] {
  grid-area: ADD;
  font-size: var(--number-size);
}
.EQ {
  grid-area: CALC;
  font-size: var(--number-size);
  color: #202020;
  background: rgb(105, 102, 218);
  background: linear-gradient(
    45deg,
    rgba(105, 102, 218, 1) 0%,
    rgba(0, 221, 255, 1) 100%
  );
  transition: 300ms;
}

.EQ:hover {
  color: white;
}

#screen {
  grid-area: screen;
  text-align: right;
  font-size: 1.3rem;
  font-weight: lighter;
  min-height: 1.5rem;
  word-wrap: break-word;
}

#low-screen {
  min-height: 3rem;
  grid-area: low-screen;
  text-align: right;
  word-wrap: break-word;
  font-size: 3rem;
}

.error {
  color: var(--text-color-error);
  text-shadow: 0px 0px 7px var(--text-color-error);
}

.hint {
  width: auto;
  position: fixed;
  background-color: #222;
  color: var(--text-color);
  text-shadow: 0px 0px 7px var(--text-color);
  font-weight: lighter;
  padding: 10px;
  border-radius: 0px 0px 5px 5px;
  top: 0;
  padding-right: 30px;
  word-wrap: break-word;
  hyphens: auto;
  text-align: center;
  transition: 500ms ease;
}

.hint > span:nth-of-type(1) {
  position: absolute;
  top: 5px;
  right: 10px;
  cursor: pointer;
}

.removed {
  top: -30px;
  opacity: 0;
}