:root {
  --primary-green400: hsl(172, 67%, 45%);
  --Green-900: hsl(183, 100%, 15%);
  --Grey-500: hsl(186, 14%, 43%);
  --Grey-400: hsl(184, 14%, 56%);
  --Grey-200: hsl(185, 41%, 84%);
  --Grey-50: hsl(189, 47%, 97%);
}
* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}
body {
  font-family: "Space Mono", sans-serif;
  font-size: 24px;
  background-color: var(--Grey-200);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  flex-direction: column;
  gap: 2rem;
}
.logo {
  margin-top: 1rem;
}
main {
  display: grid;
  gap: 50px;
  grid-template-columns: 1fr 1fr;
  background-color: white;
  border-radius: 1.5rem;
  padding: 2rem;
}
.form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin: 1rem 0;
}
.form h3 {
  color: var(--Grey-500);
  font-size: 0.8rem;
  margin: 0;
  margin-bottom: 0.5rem;
}

.input {
  background-color: var(--Grey-50);
  border: 2px solid transparent;
  outline: none;
  cursor: pointer;
  height: 1rem;
  padding: 1.5rem;
  color: var(--Green-900);
  font-family: inherit;
  font-size: 1.5rem;
  font-weight: 600;
  text-align: right;
  border-radius: 0.5rem;
  caret-color: var(--primary-green400);
}
.input:hover,
.input:focus {
  border: 2px solid var(--primary-green400);
}
.bill-input,
.people-input {
  position: relative;
}
.icon {
  position: absolute;
  z-index: 100;
  bottom: 15px;
  left: 15px;
}
.tip-buttons {
  display: grid;
  grid-template-columns: repeat(3, 6.4rem);
  grid-template-rows: repeat(2, 1fr);
  gap: 0.5rem;
}
.tip-buttons button {
  font-family: inherit;
  font-size: 1.25rem;
  font-weight: 600;
  cursor: pointer;
  background-color: var(--Green-900);
  border: 1px solid transparent;
  outline: none;
  color: white;
  border-radius: 0.25rem;
}
.tip-buttons button:hover {
  background-color: var(--Grey-200);
  color: var(--Green-900);
}
#selected-tip {
  background-color: var(--primary-green400);
  color: var(--Green-900);
}
#custom {
  padding: 1.25rem;
  font-size: 1rem;
}
#custom::placeholder {
  text-align: center;
}
.shake {
  animation: shake 1.5s ease;
}

@keyframes shake {
  10%,
  90% {
    transform: translate3d(-0.1rem, 0, 0);
  }
  20%,
  80% {
    transform: translate3d(0.1rem, 0, 0);
  }
  30%,
  50%,
  70% {
    transform: translate3d(-0.1rem, 0, 0);
  }
  40%,
  60% {
    transform: translate3d(0.1rem, 0, 0);
  }
}

.final-calc {
  background-color: var(--Green-900);
  border-radius: 0.75rem;
  padding: 2rem;
  display: flex;
  flex-direction: column;
}
.tip-amount,
.total {
  display: flex;
  justify-content: space-between;
  margin-bottom: 2rem;
}
.tip-amount p,
.total p {
  margin: 0;
  color: white;
  font-size: 1rem;
  font-weight: 600;
}
.tip-amount h3,
.total h3 {
  margin: 0;
  color: var(--primary-green400);
}
.tip-amount p span,
.total p span {
  color: var(--Grey-500);
  font-size: 0.75rem;
}
#reset {
  width: 100%;
  margin-top: auto;
  background-color: var(--primary-green400);
  color: var(--Green-900);
  font-family: inherit;
  border: none;
  outline: none;
  border-radius: 0.25rem;
  font-size: 1.25rem;
  cursor: pointer;
  padding: 0.25rem;
  font-weight: 600;
}
#reset:hover {
  background-color: var(--Grey-200);
}
.error {
  border-color: red;
}
.input.error:focus {
  border: 2px solid red;
}
@media (max-width: 646px) {
  main {
    grid-template-columns: 1fr;
    border-radius: 1.5rem 1.5rem 0 0;
    width: 100%;
    height: calc(100vh - 6rem);
    overflow: auto;
  }

  .tip-buttons {
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(3, 1fr);
  }
  .input {
    width: 100%;
  }
  #custom {
    font-size: 1.5rem;
  }
}