body {
  font-family: Arial, sans-serif;
  background-color: #f0f4f8;
  display: flex;
  justify-content: center;
  padding: 50px;
}

.container {
  background: white;
  padding: 30px;
  border-radius: 10px;
  width: 100%;
  max-width: 400px;
  box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

h1 {
  text-align: center;
}

.input-section {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

input {
  flex: 1;
  padding: 10px;
}

button {
  padding: 10px;
  background-color: #4caf50;
  border: none;
  color: white;
  cursor: pointer;
}

button:hover {
  background-color: #45a049;
}

ul {
  list-style: none;
  padding: 0;
}

li {
  background: #eee;
  margin: 5px 0;
  padding: 10px;
  border-radius: 5px;
  position: relative;
}

li.completed {
  text-decoration: line-through;
  color: gray;
}

li::after {
  content: "❌";
  position: absolute;
  right: 10px;
  cursor: pointer;
}