CSS（層疊樣式表）是用于設計網頁樣式的標記語言，可以將頁面地圖的外觀和排版完全分離出來。CSS中有許多有用的屬性來幫助我們控制頁面地圖的呈現方式。其中，一些屬性可以自動地為我們完成任務。在本文中，我們將介紹四種常見的自動CSS屬性。

1. Width and Height

If you want an element to automatically fill the available space, without specifying an explicit size, you can use the CSS 'width' and 'height' properties with a value of 100%. This will cause the element to expand to fill the width and height of its parent container, assuming the dimensions of the parent have been set explicitly or are otherwise known.

2. Margin

The 'margin' property can be used to automatically center an element horizontally within its parent container. To do this, set the left and right margins to 'auto'. For example:

.my-element {
margin-left: auto;
margin-right: auto;
}

3. Display

The 'display' property can automatically alter the flow of content in a page, either by removing elements from it or by making them inline. The 'display: none' property can be used to hide an element entirely from view, while 'display: inline-block' can be used to make a block-level element behave more like an inline element, while still retaining its block-level properties.

4. Overflow

The 'overflow' property can be used to automatically generate scroll bars within an element when its content overflows its bounds. For example, a long paragraph of text that is too wide for its container can be made to scroll horizontally by setting the 'overflow-x' property to 'scroll'. This will create a horizontal scroll bar that the visitor can use to scroll left and right to view the entire paragraph.

總之，CSS屬性是非常有用的工具，可以幫助我們控制頁面地圖的外觀和排版方式。通過了解這些自動屬性，我們可以更好地使我們的代碼變得容易管理，同時也提高了我們的工作效率。