CSSだけで簡単に吹き出しを作成する方法4つ！<!DOCTYPE HTML> <html lang="ja"> <head> <meta charset="UTF-8"> <style type="text/css"> * { box-sizing: border-box; } .wrapper { padding: 30px; position: relative; } .box { position: relative; background: #ccc; height: 50px; width: 100px; margin-bottom: 20px; } .box:after { content: ''; position: absolute; border-top: 10px solid #ccc; border-right: 5px solid transparent; border-left: 5px solid tran
