style.css

/* ROBOTO FONT */
@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;500&display=swap');
/* POPPINS FONT */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500&display=swap');
* {
  font-family: 'Roboto',sans-serif;
}
body {
  box-sizing: content-box; 
}
h1 {
  font-family: 'Poppins', sans-serif;
  font-size: 30px;
  font-weight: normal;
  text-align: center;
  margin-top: 0;
  margin-bottom: 20px;
  color: #333;
}
.todo_list {
  max-width: 400px;
  display: block;
  margin: 25px auto 0;
  padding: 30px;
  border-radius: 10px;
  border: solid 1px #ddd;
 }
.create_new_todo {
  display: flex;
  text-align: center;
}
button {
  padding: 10px;
  cursor: pointer;
}
.message {
  width: 100%;
  padding: 10px; 
  box-sizing: border-box;
}
.todo {
  padding-left: 0;
}
.todo li {
  list-style-type: none;
}
.todo li:not(:last-child) {
  border-bottom: 1px solid #ddd;
}
/* Скрытие программного чекбокса */
.todo input {
  opacity: 0;
  position: absolute;
}
/* Стиль чекбокса для input, label*/
.todo input, label {
  display: inline-block;
  vertical-align: middle;
  padding: 10px;
  cursor: pointer;
}
/* Поле для input с соседним label*/
.todo input + label:before {
  content: '';
  border-radius: 5px;
  border: 2px solid #ddd;
  display: inline-block;
  vertical-align: middle;
  width: 10px;
  height: 10px;
  padding: 2px;
  margin-right: 10px;
  text-align: center;
}
/* Галочка */
.todo input:checked + label:before {
  content: "";
  display: inline-block;
  width: 1px;
  height: 5px;
  border: solid blue;
  border-width: 0 3px 3px 0;
  transform: rotate(45deg);
  border-radius: 0;
  margin: 0 15px 5px 5px;
}
.li {
  position: relative;
}
.li label {
  display: block;
  text-overflow: ellipsis;
  overflow: hidden;
}
.close {
  position: absolute;
  right: 0;
  padding: 10px;
  cursor: pointer;
  border: 1px solid transparent;
}
.close:hover {
  background: #ddd;
}