* {
  box-sizing: border-box;
  font-family: Arial, sans-serif;
}

body {
  background: #1e1e2f;
  color: #fff;
  display: flex;
  justify-content: center;
  padding: 40px 10px;
}

.container {
  width: 100%;
  max-width: 600px;
  background: #2b2b40;
  padding: 20px;
  border-radius: 10px;
}

h1 {
  text-align: center;
  margin-bottom: 20px;
}

.input-area {
  display: flex;
  gap: 10px;
}

input {
  flex: 1;
  padding: 10px;
  font-size: 16px;
}

button {
  padding: 10px 15px;
  border: none;
  background: #ff9800;
  cursor: pointer;
  font-weight: bold;
}

ul {
  list-style: none;
  padding: 0;
  margin-top: 20px;
}

li {
  background: #3a3a55;
  padding: 10px;
  margin-bottom: 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-radius: 5px;
}

li.done {
  text-decoration: line-through;
  opacity: 0.6;
}

li button {
  background: red;
  color: #fff;
  padding: 5px 8px;
}