摘要：
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <style type="text/css"> #header { height: 60px; /*高度60*/ background: yellow; /*背景 阅读全文
摘要：
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <script type="text/javascript"> window.onload = function(){ var start = document. 阅读全文