body { font-family: Arial, sans-serif; background-color: #f4f4f9; display: flex; justify-content: center; padding: 50px; }
.container { width: 100%; max-width: 600px; background: white; padding: 20px; border-radius: 8px; box-shadow: 0 0 10px rgba(0,0,0,0.1); }
.form-container { display: flex; gap: 10px; margin-bottom: 20px; }
input { flex: 1; padding: 10px; border: 1px solid #ccc; border-radius: 4px; }
button { padding: 10px 15px; background: #28a745; color: white; border: none; border-radius: 4px; cursor: pointer; }
ul { list-style: none; padding: 0; }
li { background: #fff; padding: 10px; border-bottom: 1px solid #eee; display: flex; justify-content: space-between; align-items: center; }
.completed { text-decoration: line-through; color: #888; }
.actions button { margin-left: 5px; }