*,
::after,
::before {
  box-sizing: border-box;
  margin: 0;
  padding: 0; 
}

:root {
  --greyish-clr: #eee6e6;
  --white-clr: #fff; 
  --grey-clr: #b9b2b2; 
  --black-clr: #000; 
  --red-clr: red; 
  --green-clr: #1dc61d;
  --green-clr2: #9ce99c; 
  --yellow-clr: yellow; 
}

body {
  font-family: Arial, Helvetica, sans-serif;
  font-size: 1.2rem;
  background-color: var(--greyish-clr);
  padding: 20px; 
}

main {
  display: flex;
  flex-flow: column nowrap; 
  gap: 1rem; 
  align-items: center;
}

.register {
  width: 500px; 
  height: 100vh; 
  display: flex;
  flex-flow: column nowrap; 
  gap: 1rem; 
  align-items: center;
}

.customer-container {
  display: flex;
  gap: 1rem; 
  align-items: center;
}


:is(.input-container, .change-due) {
  background-color: var(--white-clr);
  padding: 1rem;
  border-radius: 10px; 
}

.input-container {
  display: flex;
  flex-flow: column nowrap; 
  gap: 0.5rem; 
}

:is(.cash, .purchase-btn) {
  font-size: 1.2rem;
  padding: 0.2rem 0.5rem; 
  border-radius: 10px;
}

.purchase-btn {
  background-color: var(--green-clr);
  background-image: linear-gradient(var(--green-clr), var(--green-clr2) );
  font-weight: bold;
  cursor: pointer;
}

.change-due {
  min-width: 11rem;
  min-height: 9rem; 
  
}

.coint-slot {
  background-color: var(--black-clr);
  width: 30px; 
  height: 10px; 
  border-radius: 5px 5px 0px 0px;
  position: absolute;
  top: -6px; 
  left: 15.5rem; 
}

.register-body {
  width: 100%; 
  height: 400px; 
  background-color: var(--red-clr);
  display: flex; 
  gap: 1rem; 
  align-items: center; 
  padding: 1rem; 
  border-radius: 10px;
  position: relative;
}

.screen-btns {
  display: flex;
  flex-flow: column nowrap;
  gap: 1rem; 
}

.screen {
  background-color: var(--grey-clr);
  font-family:'Courier New', Courier, monospace; 
  font-weight: bold;
  display: flex; 
  justify-content: center;
  align-items: center;
  padding: 1rem 2rem; 
}

.buttons-container {
  width: 70%; 
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.2rem; 
}

.buttons-container .btn {
  font-size: 1.2rem;
  padding: 1rem 2rem; 
  border-radius: 10px;
  background-color: var(--white-clr);
  cursor: pointer; 
}

.buttons .btn:last-of-type {
  background-color: var(--yellow-clr);
}

.drawer {
  background-color: var(--white-clr);
  display: flex;
  flex-flow: column nowrap;
  width: 280px; 
  padding: 1rem; 
  border-radius: 10px;
}

.drawer .center {
  text-align: center;
  margin-bottom: 0.5rem; 
}


@media (max-width: 590px) {
  html {
    font-size: 12px; 
  }

  .customer-container {
    flex-wrap: wrap;
    justify-content: center;
  }

  .register {
    width: 350px; 
  }

  .register-body {
    height: 300px; 
  }

  
}