/* start global rules  */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
:root {
  --theme-text-color: white;
  --theme-background: hsl(222, 26%, 31%);
  --theme-elements-background: hsl(223, 31%, 20%);
  --theme-alt-elements-background: hsl(6, 63%, 50%);
  --theme-buttons-color: hsl(221, 14%, 31%);
  --theme-buttons-background: hsl(30, 25%, 89%);
  --theme-buttons-border-background: hsl(29, 16.2%, 64.9%);
  --theme-lighter-background: hsl(225, 20.8%, 49%);
  --theme-lighter-border-color: hsl(221, 28%, 38%);
  --theme-special-background: hsl(6, 63.1%, 50%);
  --theme-special-border-color: rgb(196, 26, 7);
  --theme-special-ele-color: white;
  /* start theme 1  */
  /* --theme1-text-color: white;
  --theme1-background: hsl(222, 26%, 31%);
  --theme1-elements-background: hsl(223, 31%, 20%);
  --theme1-alt-elements-background: hsl(6, 63%, 50%);
  --theme1-buttons-color: hsl(221, 14%, 31%);
  --theme1-buttons-background: hsl(30, 25%, 89%);
  --theme1-buttons-border-background: hsl(29, 16.2%, 64.9%);
  --theme1-lighter-background: hsl(225, 20.8%, 49%);
  --theme1-lighter-border-color: hsl(221, 28%, 38%);
  --theme1-special-background: hsl(6, 63.1%, 50%);
  --theme1-special-border-color: rgb(196, 26, 7);
  --theme1-special-ele-color: white; */
  /* end theme 1  */
  /* start theme 2  */
  /* --theme2-text-color: black;
  --theme2-background: hsl(0, 0%, 90%);
  --theme2-elements-background: hsl(0, 5.2%, 81%);
  --theme2-alt-elements-background: hsl(24.9, 98%, 40%);
  --theme2-buttons-color: hsl(221, 14%, 31%);
  --theme2-buttons-background: hsl(45, 7.1%, 89%);
  --theme2-buttons-border-background: rgb(109, 91, 75);
  --theme2-lighter-background: hsl(185.3, 41.8%, 37.1%);
  --theme2-lighter-border-color:rgb(27, 96, 102);
  --theme2-special-background: hsl(24.9, 98%, 40%);
  --theme2-special-border-color: rgb(148, 66, 8);
  --theme2-special-ele-color: white; */
  /* end theme 2  */
  /* start theme 3  */
  /* --theme3-text-color: hsl(52, 100%, 62%);
  --theme3-background: hsl(268, 75%, 9%);
  --theme3-elements-background: hsl(267.9, 70.5%, 12%);
  --theme3-alt-elements-background: hsl(176, 100%, 43.9%);
  --theme3-buttons-color: hsl(52, 100%, 62%);
  --theme3-buttons-background: hsl(281.2, 89.4%, 25.9%);
  --theme3-buttons-border-background: rgb(127, 3, 184);
  --theme3-lighter-background: hsl(268.2, 47.7%, 21%);
  --theme3-lighter-border-color:rgb(82, 3, 172);
  --theme3-special-background: hsl(176, 100%, 43.9%);
  --theme3-special-border-color: rgb(4, 163, 153);
  --theme3-special-ele-color: black; */
  /* end theme 3  */

}
body {
  font-family: "Spartan", sans-serif;
  background-color: var(--theme-background);
  color: var(--theme-text-color);
}
.container {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  text-transform: uppercase;
}
.calculator {
  width: 27rem;
}
@media (max-width: 500px) {
    html {
        font-size: 13px;
    }
    .calculator {
        width: 22rem;
    }
}
.lighter {
  background-color: var(--theme-lighter-background) !important;
  color: white !important;
  border-color: var(--theme-lighter-border-color) !important;
}
.special {
  background-color: var(--theme-special-background) !important;
  color: var(--theme-special-ele-color) !important;
  border-color: var(--theme-special-border-color) !important;
}
/* end global rules  */
/* start heading  */
.heading {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.heading > h1 {
  font-size: 2.5rem;
  /* text-transform: uppercase; */
}
.heading .theme-container {
  display: flex;
  align-items: center;
}
.heading .theme-container .theme-changer {
  margin-bottom: 19%;
  margin-left: 1rem;
}
.heading .theme-container .theme-changer .theme-numbers {
  display: flex;
  justify-content: space-around;
}
.heading .theme-container .theme-changer .theme-numbers p {
  cursor: pointer;
}
.heading .theme-container .theme-changer .theme-box {
  width: 6rem;
  height: 2rem;
  background: var(--theme-elements-background);
  border-radius: 50px;
  margin-top: 6px;
  position: relative;
}
.heading .theme-container .theme-changer .theme-box .theme-point {
  width: 10px;
  height: 10px;
  background: var(--theme-alt-elements-background);
  border-radius: 50%;
  position: absolute;
  left: 15%;
  top: 50%;
  transform: translate(-50%, -50%);
  transition: 0.3s;
}
/* for the first theme it should be left porperty 15%; */
/* for the second theme it should be left porperty 47%; */
/* for the third theme it should be left porperty 83%; */
/* end heading  */
/* start calculator display  */
.calculator-display {
  min-height: 8rem;
  background-color: var(--theme-elements-background);
  padding: 1.5rem 1.5rem 2rem;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  justify-content: space-between;
  letter-spacing: 1px;
  border-radius: 15px;
  text-align: right;
  word-wrap: anywhere;
  margin-bottom: 2rem;
}
.calculator-display .previous-operation {
  margin-bottom: 10px;
}
.calculator-display .current-operation {
  font-size: 2rem;
  font-weight: bold;
}
/* end calculator display  */
/* start calculator buttons  */
.calculator-buttons {
  min-height: 20rem;
  background-color: var(--theme-elements-background);
  padding: 1rem;
  border-radius: 15px;
}
.calculator-buttons .calc-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(50px, 1fr));
  grid-template-rows: repeat(5, 3rem);
  gap: 1rem 1.25rem;
}
.calculator-buttons .calc-grid button {
  border: none;
  outline: none;
  background-color: var(--theme-buttons-background);
  color: var(--theme-buttons-color);
  text-transform: uppercase;
  border-radius: 7px;
  border-bottom: 4px solid var(--theme-buttons-border-background);
  font-size: 2rem;
  font-weight: bold;
  cursor: pointer;
  transition: 0.3s;
}
.calculator-buttons .calc-grid button:active {
  transform: translateY(5px);
}
.calculator-buttons .calc-grid button[data-delete="reset"] {
  grid-column: span 2;
}
.calculator-buttons .calc-grid button[data-equal] {
  grid-column: span 2;
}
.calculator-buttons .calc-grid button[data-delete] {
    font-size: 1.5rem;;
}
/* end calculator buttons  */