body {
  background-color: orange;
  font-family: Arial, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 40px;
  margin: 0;
}


h1 {
  color: black;
  margin-bottom: 40px;
}


.todo-list {
  list-style-type: none;
  padding: 0;
  margin: 0;
  width: 100%;
  max-width: 450px;
}


.todo-list > li {
  background-color: white;
  margin-bottom: 20px;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}


.sub-item {
  list-style-type: square;
  margin-top: 15px;
  margin-left: 25px;
}


.sub-item-link {
  text-decoration: none;
}

.sub-item-link:link { color: blue; }
.sub-item-link:visited { color: purple; }
.sub-item-link:hover { color: red; }
.sub-item-link:active { color: orange; }
.sub-item-link:focus { outline: 2px solid green; }