style.css

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Poppins", sans-serif;
  color: #fff;
}
body {
  width: 100%;
  height: 100vh;
  background: linear-gradient(120deg, #0d1017, rgb(15, 50, 102));
  display: flex;
  justify-content: center;
  align-items: center;
}
header {
  font-size: 50px;
}
header,
form {
  min-height: 20vh;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}
button i {
  color: #fff;
}
input {
  border: 2px solid #32363e;
  font-size: 12px;
  outline: none;
  border-radius: 7px;
  padding: 7px 15px;
  width: 100%;
  background: #181b23;
  height: 41px;
}
button.todo-button {
  border: none;
  outline: none;
  padding: 9px 15px;
  border-radius: 7px;
  color: #fff;
  cursor: pointer;
  background: #181b23;
  transition: 0.1s ease-in-out;
  position: absolute;
  right: 1px;
}
button.submit:hover {
  background: #65a0f3;
  /* border: 2px solid #39699d; */
}
.todo-container {
  width: 100%;
}
.todo {
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-width: 30%;
  padding-left: 15px;
  margin-bottom: 10px;
  background: #fff;
  transition: 1s ease-in-out;
}
li {
  list-style: none;
  font-size: 20px;
  font-weight: bold;
  color: #000;
  flex: 1;
}
.delete-button,
.check-button {
  outline: none;
  border: none;
  padding: 15px;
  font-size: 20px;
  cursor: pointer;
  text-align: right;
}

.check-button {
  background: rgb(11, 212, 162);
}
.delete-button {
  background: #ff6f47;
  margin-left: 15px;
}

.line-through {
  text-decoration: line-through;
  text-decoration-color: rgb(0 223 9);
  text-decoration-thickness: 5px;
  color: #00000080;
}
.delete-item {
  transform: translateY(10rem) rotateZ(20deg);
  opacity: 0;
  animation: hide 2s ease-in-out;
}