:root {
  --bg-main: hsl(222, 26%, 31%);
  --bg-keypad: hsl(223, 31%, 20%);
  --bg-screen: hsl(224, 36%, 15%);

  --btn-bg: hsl(225, 21%, 49%);
  --btn-shadow: hsl(224, 28%, 35%);

  --equal-bg: hsl(6, 63%, 50%);
  --equal-shadow: hsl(6, 70%, 34%);

  --key-bg: hsl(0, 0%, 90%);
  --key-shadow: hsl(28, 16%, 65%);

  --text: white;
}

.theme-2 {
  --bg-main: hsl(0, 0%, 90%);
  --bg-keypad: hsl(0, 5%, 81%);
  --bg-screen: hsl(0, 0%, 93%);

  --btn-bg: hsl(185, 42%, 37%);
  --btn-shadow: hsl(185, 58%, 25%);

  --equal-bg: hsl(25, 98%, 40%);
  --equal-shadow: hsl(25, 99%, 27%);

  --key-bg: hsl(0, 0%, 90%);
  --key-shadow: hsl(35, 11%, 61%);

  --text: hsl(60, 10%, 19%);
}


.theme-3 {
  --bg-main: hsl(268, 75%, 9%);
  --bg-keypad: hsl(268, 71%, 12%);
  --bg-screen: hsl(268, 71%, 12%);

  --btn-bg: hsl(281, 89%, 26%);
  --btn-shadow: hsl(285, 91%, 52%);

  --equal-bg: hsl(176, 100%, 44%);
  --equal-shadow: hsl(177, 92%, 70%);

  --key-bg: hsl(268, 47%, 21%);
  --key-shadow: hsl(290, 70%, 36%);

  --text: hsl(52, 100%, 62%);
}

body {
     background-color: var(--bg-main);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    font-family: "Red Hat Text", sans-serif;
    flex-direction: column;

}
main {
  width: 100%;
  max-width: 350px;
}
.top-part {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.theme {
  display: flex;
  align-items: end;
  gap: 20px;
  
}

.theme-control {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
}
.numbers {
  display: flex;
  justify-content: space-between;
  width: 60px;
  font-size: 12px;
}

.toggle-container {
  width: 65px;
  height: 20px;
  background-color: hsl(223, 31%, 20%);
  border-radius: 20px;
  padding: 5px;
  cursor: pointer;
  display: flex;
  align-items: center;
}

.toggle-circle {
  width: 15px;
  height: 15px;
  background-color: var(--equal-bg);
  border-radius: 50%;
  transition: 0.3s;
}

.res {
  background-color: var(--bg-screen);
  padding: 25px;
  border-radius: 10px;
  margin: 20px 0;
  text-align: right;
}
#screen {
  font-size: 32px;
  font-weight: bold;
}
.buttons {
   background-color: var(--bg-keypad);
  padding: 20px;
  border-radius: 10px;

  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 15px;
}
button:active {
  transform: translateY(2px);
}
button {
    background-color: var(--key-bg);
  box-shadow: 0 3px var(--key-shadow);
  padding: 10px;
  font-size: 20px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}
button:hover {
  filter: brightness(1.1);
}
.reset {
  grid-column: span 2;
   background-color: var(--btn-bg);
  box-shadow: 0 3px var(--btn-shadow);
}

.equal {
  grid-column: span 2;   background-color: var(--equal-bg);
  box-shadow: 0 3px var(--equal-shadow);
}
.del{ background-color: var(--btn-bg);
  box-shadow: 0 3px var(--btn-shadow);}