body {
  background-color: #f0f0f0;
  font-family: Arial, sans-serif;
  padding: 20px;
}
.conteiner {
  max-width: 400px;
  margin: 0 auto;
  background-color: #fff;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}
h1 {
  text-align: center;
  color: #333;
}

.todo-list {
  background-color: #ffffff;

  list-style-type: none;
  margin-left: auto;
  margin-right: auto;
}
.sub-item-link {
  text-decoration: none;
}
a:hover {
  color: red;
}
.sub-item {
  list-style-type: square;
}
.todo-list li {
  margin-bottom: 15px;
  line-height: 1.6;
  padding: 10px;
  background-color: #e5f1e5;
  border-radius: 10px;
  position: relative;
}
a:active {
  color: red;
}
a:focus {
  outline: 2px solid blue; /* customize thickness and color */
}
a:visited {
  color: purple; /* or any color you like */
}