style.css

body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 400px;
}

h1 {
    text-align: center;
}

form {
    display: flex;
    margin-bottom: 20px;
}

input[type="text"] {
    flex: 1;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px 0 0 4px;
}

button {
    padding: 10px;
    background: #28a745;
    color: white;
    border: none;
    border-radius: 0 4px 4px 0;
    cursor: pointer;
}

button:hover {
    background: #218838;
}

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

li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px;
    background: #f9f9f9;
    margin-bottom: 10px;
    border-radius: 4px;
}

li.completed {
    text-decoration: line-through;
    color: #777;
}

li button {
    background: #dc3545;
    border: none;
    color: white;
    padding: 5px 10px;
    border-radius: 4px;
    cursor: pointer;
}

li button:hover {
    background: #c82333;
}