* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: system-ui, sans-serif;
    background: #f5f5f5;
    display: flex;
    justify-content: center;
    padding: 40px 16px;
}

.container {
    width: 100%;
    max-width: 500px;
}

h1 {
    margin-bottom: 20px;
    color: #333;
}

.add-form {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
}

.add-form input {
    flex: 1;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 16px;
}

.add-form button {
    padding: 10px 20px;
    background: #c300ff;
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
}

.add-form button:hover {
    background: #357abd;
}

.todo {
    display: flex;
    align-items: center;
    gap: 10px;
    background: #fff;
    padding: 12px 16px;
    border-radius: 6px;
    margin-bottom: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.todo.done span {
    text-decoration: line-through;
    color: #999;
}

.todo span {
    flex: 1;
}

.todo button {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 18px;
    padding: 4px 8px;
}

.empty {
    color: #999;
    text-align: center;
    margin-top: 40px;
}