body {
    font-family: Arial, sans-serif;
    max-width: 600px;
    margin: 40px auto;
    padding: 20px;
    background-color: #f5f5f5;
}

h1 {
    text-align: center;
    font-style: italic;
}

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

input[type="text"] {
    flex: 1;
    padding: 10px;
    font-size: 16px;
}

button {
    padding: 10px 15px;
    font-size: 16px;
    margin-left: 10px;
    border-radius: 5px;
}

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

li {
    background: #fff;
    margin-bottom: 10px;
    padding: 10px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-left: 5px solid transparent;
}

li.completed {
    text-decoration: line-through;
    opacity: 0.6;
    border-left-color: red;
}

.task-text {
    flex: 1;
    margin-left: 10px;
}

.checkbox {
    cursor: pointer;
}

.delete-btn {
    background: red;
    color: white;
    border: none;
    cursor: pointer;
    padding: 5px 8px;
}