今日学习内容：html 块
对 HTML 进行分类（设置类），使我们能够为元素的类定义 CSS 样式。
为相同的类设置相同的样式，或者为不同的类设置不同的样式。
<!DOCTYPE html> <html> <head> <style> .cities { background-color:black; color:white; margin:20px; padding:20px; } </style> </head> <body> <div class="cities"> <h2>London</h2> <p> London is the capital city of England. It is the most populous city in the United Kingdom, with a metropolitan area of over 13 million inhabitants. </p> </div> </body> </html>
分类块级元素
HTML <div> 元素是块级元素。它能够用作其他 HTML 元素的容器。
设置 <div> 元素的类，使我们能够为相同的 <div> 元素设置相同的类：
<!DOCTYPE html> <html> <head> <style> .cities { background-color:black; color:white; margin:20px; padding:20px; } </style> </head> <body> <div class="cities"> <h2>London</h2> <p>London is the capital city of England. It is the most populous city in the United Kingdom, with a metropolitan area of over 13 million inhabitants.</p> </div> <div class="cities"> <h2>Paris</h2> <p>Paris is the capital and most populous city of France.</p> </div> <div class="cities"> <h2>Tokyo</h2> <p>Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the most populous metropolitan area in the world.</p> </div> </body> </html>
分类行内元素
HTML <span> 元素是行内元素，能够用作文本的容器。
设置 <span> 元素的类，能够为相同的 <span> 元素设置相同的样式。
<!DOCTYPE html> <html> <head> <style> span.red {color:red;} </style> </head> <body> <h1>My <span class="red">Important</span> Heading</h1> </body> </html>