@import url("https://fonts.googleapis.com/css2?family=Roboto:ital,wght@0,100..900;1,100..900&display=swap");

:root {
  --font1:
    "Segoe UI", Tahoma, Geneva, Verdana, sans-serif; /* Microsoft default  */
  --font2: "Roboto", sans-serif;
  --displayColor: rgba(0, 0, 0, 0.75);
  --shadowColor: rgba(0, 0, 0, 0.2);
  --letterSpacing: 0.7px;
  --color1: #000000;
  --color2: #333333;
  --color3: #666666;
  --color4: #999999;
  --color5: #c0c0c0;
  --color6: #e9f8f3;
  --color7: #ffffff;
  --copyColor1: #404040;
  --copyColor2: #666666;
  --copyColor3: #808080;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  font-family: var(--font1);
  font-weight: normal;
}

body {
  padding: 0;
  margin: 0;
  background-color: var(--color7);
}

.container {
  min-height: 100dvh;
  display: grid;
  grid-template-rows: auto 1fr auto;
  place-content: center;
}

h1 {
  font-family: var(--font2);
  font-size: 28px;
  color: var(--color1);
  padding: 20px 0;
}

.calculator-grid {
  display: grid;
  justify-content: center;
  align-content: center;
  grid-template-columns: repeat(4, 76px);
  grid-template-rows: minmax(100px, auto) repeat(5, 48px);
  background-color: var(--color6);
  gap: 3px;
  border: 1px solid var(--shadowColor);
  padding: 100px 16px 16px 16px;
  border-radius: 10px;
  box-shadow: 0 2px 16px 0 var(--shadowColor);
}

.calculator-grid > button {
  background-color: #f3fbf9;
  font-size: 20px;
  border: 1px solid var(--shadowColor);
  border-radius: 4px;
  outline: none;
  box-shadow: 0 2px 16px 0 var(--shadowColor);
  cursor: pointer;
}

button[data-all-clear],
button[data-delete] {
  background-color: #ff8c00;
  font-size: 14px;
  color: var(--color1);
}

button[data-all-clear]:hover,
button[data-delete]:hover {
  background-color: #f0982c;
}

button[data-all-clear]:active,
button[data-delete]:active {
  background-color: #f79d2f;
  color: var(--color2);
}

button[data-percentage] {
  font-size: 16px;
  font-weight: 600;
}

button[data-operation],
button[data-percentage] {
  background-color: #fcf8f5;
  color: var(--color3);
}

button[data-operation]:hover,
button[data-percentage]:hover {
  background-color: #faf4f1;
  background-color: #d7dddb;
}

button[data-operation]:active,
button[data-percentage]:active {
  background-color: #faf3ee;
  background-color: #e9eceb;
  color: var(--color4);
}

button[data-number],
button[data-negate] {
  background-color: #ffffff;
}

button[data-number]:hover,
button[data-negate]:hover {
  background-color: #ecf7f4;
}

button[data-number]:active,
button[data-negate]:active {
  background-color: #fcf8f5;
  background-color: #eef1f1;
  color: var(--color2);
}

button[data-operation],
button[data-equals] {
  font-size: 24px;
  font-weight: normal;
}

button[data-equals] {
  background-color: #246b62;
  color: var(--color7);
  border: none;
}

button[data-equals]:hover {
  background-color: #397970;
}

button[data-equals]:active {
  background-color: #4e857d;
}

.output {
  grid-column: 1 / -1;
  background-color: var(--displayColor);
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  flex-direction: column;
  min-height: 120px;
  padding: 20px 20px;
  margin-bottom: 10px;
  word-wrap: break-word;
  word-break: break-all;
  border-radius: 6px;
}

.output .previous-operand {
  color: var(--color5);
  font-size: 24px;
}

.output .current-operand {
  color: var(--color7);
  font-size: 36px;
}

#error-message {
  color: var(--color1);
  padding-top: 50px;
  text-align: center;
}

.copy {
  color: var(--copyColor1);
  font-size: 14px;
  text-align: center;
  letter-spacing: var(--letterSpacing);
  padding: 20px 0;
  margin-top: 50px;
}

.copy a {
  color: var(--copyColor1);
  text-decoration: underline dotted;
  text-decoration-color: var(--copyColor2);
  text-decoration-thickness: 1.5px;
  text-underline-offset: 6px;
}

.copy a:hover {
  color: var(--copyColor1);
  text-decoration-color: var(--copyColor3);
}

@media only screen and (max-width: 390px) {
  .calculator-grid {
    grid-template-columns: repeat(4, 66px);
    grid-template-rows: minmax(100px, auto) repeat(5, 48px);
  }

  .copy {
    padding: 8px 0;
    line-height: 1.6;
    margin: 0;
  }

  .copy a {
    text-underline-offset: 4px;
  }

  .copy2 {
    display: block;
  }
}

@media only screen and (max-width: 340px) {
  .calculator-grid {
    grid-template-columns: repeat(4, 56px);
    grid-template-rows: minmax(100px, auto) repeat(5, 48px);
    gap: 2px;
  }
}