:root {
  --main-color: #0d05ff;
  --bg-color: #f8f9fa;
  --cal-bg-color: #fff;
  --t-color: #000000;
  --btn-color: #f8f9fa;
}

.darktheme{
   /* --main-color: #413bff; */
   --bg-color: #1a1b1b;
   --cal-bg-color: #2b3035;
   --t-color: #fff;
   --btn-color: #1a1a1a;
}

* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
  font-family: Arial, Helvetica, sans-serif;
}

body {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  position: relative;
  background-color: var(--bg-color);
}

header{
  position: absolute;
  top: 30px;
  right: 80px;
}
header nav div svg{
  color: var(--t-color);
  height: 25px;
  width: 25px;
  cursor: pointer;
}
.container {
  width: 490px;
  padding: 20px 10px;
  border-radius: 10px;
  box-shadow: 5px 5px 10px rgba(0, 0, 0, 0.2),
    -5px -5px 10px rgba(0, 0, 0, 0.2);
    background-color: var(--cal-bg-color);
}

.output {
  border: solid 2px var(--main-color);
  height: 60px;
  border-radius: 10px;
  overflow: hidden;
  margin-bottom: 20px;
}

.output input {
  height: 100%;
  width: 100%;
  border: none;
  outline: none;
  font-size: 50px;
  text-align: end;
  padding-right: 20px;
  color: var(--main-color);
}

/* Hide increment (up) and decrement (down) buttons*/
input[type="number"] {
  appearance: textfield;      /* Standard property */
  -webkit-appearance: none;   /* Chrome, Safari, Edge, Opera */
  -moz-appearance: textfield; /* Firefox */
} 

#clear{
 background-color: red;
}
.output input::placeholder {
  color: var(--main-color);
}
.allbtns{
  display: flex;
}
.btns {
  display: grid;
  grid-template-columns: repeat(4, 60px);
  gap: 10px 15px;
}
.scien {
  display: grid;
  grid-template-columns: repeat(2, 60px);
  gap: 10px 15px;
  margin: 0 15px;
}

.btns button , .scien button{
  border: none;
  outline: none;
  height: 60px;
  border-radius: 50%;
  font-size: 25px;
  color: var(--t-color);
  background-color: var(--btn-color);
  box-shadow: 5px 5px 5px rgba(0, 0, 0, 0.2);
  cursor: pointer;
}

.btns button.funbtn {
  background-color: var(--main-color);
  color: #fff;
}

.btns button.equal {
  width: 135px;
  border-radius: 22px;
  background-color: darkblue;
}

.btns button:hover, .scien button:hover{
 background-color: #0d05ff61;
}

footer {
  position: absolute;
  bottom: 10px;
  color: var(--t-color);
}