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

.container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    width: 400px;
    text-align: center;
}

h1 {
    color: #333;
}

.input-area {
    display: flex;
    margin-bottom: 1rem;
}

#todo-input {
    flex-grow: 1;
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 4px;
}

#add-btn {
    padding: 0.5rem 1rem;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    margin-left: 0.5rem;
    cursor: pointer;
}

#add-btn:hover {
    background-color: #0056b3;
}

#todo-list {
    list-style: none;
    padding: 0;
    margin: 0;
    text-align: left;
}

li {
    background: #eee;
    padding: 0.75rem;
    margin-top: 0.5rem;
    border-radius: 4px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
}

li.completed {
    text-decoration: line-through;
    color: #888;
    background: #e0e0e0;
}

.delete-btn {
    background-color: #dc3545;
    color: white;
    border: none;
    padding: 0.3rem 0.6rem;
    border-radius: 4px;
    cursor: pointer;
}

.delete-btn:hover {
    background-color: #c82333;
}