* {
  
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  background-color: var(--c1);
  outline: none;
  font-family: sans-serif;
  
}


:root {
  
  --c1: #ecf0f3;
  --c2: #ffffff;
  --c3: rgba(0,0,0,0.16);
  --c4: black;
  
}


.theme1 {
  
  --c1: #121212;
  --c2: rgba(0,0,0,-0.06);
  --c3: rgba(0,0,0,0.6);
  --c4: rgba(255,255,255,0.6);
  
}


.container {
  
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  
}

.calculator {
  
  padding: 15px;
  background-color: var(--c1);
  border-radius: 30px;
  box-shadow: inset 5px 5px 12px var(--c2),5px 5px 12px var(--c3),-5px -5px 12px var(--c2),inset -5px -5px 12px var(--c3);
  display: grid;
  grid-template-columns: repeat(4,68px);
  
}


input {
  
  grid-column: span 4;
  height: 100px;
  background-color: var(--c1);
  box-shadow: inset -5px -5px 12px var(--c2),inset 5px 5px 12px var(--c3);
  border: none;
  border-radius: 10px;
  margin-bottom: 50px;
  font-size: 50px;
  text-align: right;
  padding: 0px 10px;
  color: var(--c4);
  
}


button {
  
  border: none;
  border-radius: 50%;
  height: 50px;
  width: 50px;
  box-shadow: -5px -5px 12px var(--c2),5px 5px 12px var(--c3);
  margin: 5px;
  color: var(--c4);
  
}


#theme {
  
  justify-content: center;
  align-items: center;
  
}


.img1 {
  
  height: 24px;
  width: 24px;
  
}