body {
  font-family: sans-serif;
  display: flex;
  justify-content: center;
  background: #F4F4F4;
}
.container {
  background: white;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  width: 300px;
  margin-top: 50px;
}
.input-group {
  display: flex;
  gap: 5px;
  margin-bottom: 15px;
}
input {
  flex: 1;
  padding: 5px;
}
ul {
  list-style: none;
  padding: 0;
}
li {
  padding: 10px;
  border-bottom: 1px solid #EEE;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
li.completed {
  text-decoration: line-through;
  color: gray;
}
button.del {
  background: #F44;
  color: white;
  border: none;
  padding: 5px;
  cursor: pointer;
}