更改

<input style="background: #fafafa; border-radius: 2px; padding: 4px 6px; font: 1em monospace; border: 1px solid rgba(0, 0, 0, 0.16); width: <!--{$width|escape:'html'}-->" value="<!--{$content|escape:'html'}-->" readonly><button onclick="this.previousSibling.select(); document.execCommand('copy')" style="background: #ddd; padding: 2px 4px; margin-left: 0.2em; border: none">复制</button>