CSS 样式代码：生成加粗字体、渐变背景、下边框阴影

.gui { font-weight: bold; font-size: 18px; padding: 10px; background: linear-gradient(to right, #ff0000, #00ff00); border-bottom: 2px solid #000000; box-shadow: 2px 2px 2px #888888; }