style.css

@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;700&display=swap');

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

body {
  background-color: #0093E9;
  background-image: linear-gradient(160deg, #0093E9 0%, #80D0C7 100%);
  font-family: 'Montserrat', sans-serif;
  color: #122932;
  min-height: 100vh;
}

h1 {
  font-size: 3rem;
}

header,
form{
  min-height: 20vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

form input,
form button {
  padding: 0.5rem;
  font-size: 1.5rem;
  border: none;
  background: white;
}

#add-item {
  color: #00A6A6;
  background: white;
  cursor: pointer;
  transition: all .3s ease;
}

#add-item:hover {
  color: #F49F0A;
  /* color: white; */
}

.container-list {
  display: flex;
  justify-content: center;
  align-items: center;
}

.items-list {
  min-width: 30%;
  list-style: none;
}

.item-div {
  margin: 0.5rem;
  background: white;
  color: #122932;
  font-size: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all .5s ease-out;
}

.item-div li {
  flex: 1;
}

.check-btn,
.delete-btn {
  background: #CC3363;
  color: white;
  border: none;
  padding: 0.5rem;
  cursor: pointer;
  font-size: 1rem;
}

.check-btn {
  background: #F49F0A;
}

.item {
  padding: 0 0.5rem;
}

.fa-check-circle,
.fa-minus-circle {
  pointer-events: none;
}

.completed {
  text-decoration: line-through;
  opacity: 0.7;
}

.remove {
  transform: translate(9rem) ;
  opacity: 0;
}