摘要:
1 2 3 4 5 6 7 Document 8 33 34 35 header 36 37 center 38 left 39 right 40 41 footer 42 43 阅读全文
摘要:
1.css3的flex 1 <style> 2 .ss { 3 display: flex; 4 justify-content: center; 5 align-items: center; 6 height:600px; 7 width: 1000px; 8 background-color: 阅读全文