V 站有 chrome 插件，可以预览帖子，2 站没找到，自己用 AI 写了一个，不是程序员，大佬们轻喷

function injectButtons() {
    const links = document.querySelectorAll('a.title-link');

    links.forEach(link => {
        if (link.dataset.previewInjected) return;
        link.dataset.previewInjected = "true";

        // 创建按钮
        const btn = document.createElement('span');
        btn.innerText = '预览';
        btn.className = 'libra-preview-btn';
        
        // 点击逻辑
        btn.onclick = (e) => {
            e.preventDefault();
            e.stopPropagation(); // 阻止触发 a 标签的跳转
            openPreview(link.href);
        };

        // 关键改动：插在 a 标签内部的末尾，这样它永远跟着文字跑
        link.appendChild(btn);
    });
}

// --- 基础逻辑保持不变 ---
const overlay = document.createElement('div');
overlay.id = 'libra-preview-overlay';
document.body.appendChild(overlay);

const modal = document.createElement('div');
modal.id = 'libra-preview-modal';
modal.innerHTML = `
    <div class="libra-modal-header">
        <span class="libra-modal-title">快速预览</span>
        <span class="libra-close-btn">关闭 (Esc)</span>
    </div>
    <iframe id="libra-preview-iframe"></iframe>
`;
document.body.appendChild(modal);

const iframe = document.getElementById('libra-preview-iframe');

function openPreview(url) {
    iframe.src = url;
    overlay.style.display = 'block';
    modal.style.display = 'flex';
    document.body.style.overflow = 'hidden';
}

function closePreview() {
    overlay.style.display = 'none';
    modal.style.display = 'none';
    iframe.src = '';
    document.body.style.overflow = '';
}

overlay.addEventListener('click', closePreview);
document.querySelector('.libra-close-btn').addEventListener('click', closePreview);
document.addEventListener('keydown', (e) => { if (e.key === 'Escape') closePreview(); });

const observer = new MutationObserver(injectButtons);
observer.observe(document.body, { childList: true, subtree: true });
injectButtons();

{
  "manifest_version": 3,
  "name": "2libra 预览助手",
  "version": "1.1",
  "description": "点击标题旁边的预览按钮，直接弹窗查看帖子内容",
  "permissions": ["storage"],
  "content_scripts": [
    {
      "matches": ["*://*.2libra.com/*"],
      "js": ["content.js"],
      "css": ["style.css"]
    }
  ]
}

/* 预览按钮：极简、彩色、紧凑 */
.libra-preview-btn {
    display: inline-block !important; /* 强制行内 */
    width: max-content !important; /* 宽度严格由文字决定 */
    height: auto !important;
    padding: 1px 4px !important; /* 极小内边距，紧紧包裹 */
    margin-left: 3px !important; /* 与标题相隔 3 像素 */
    
    font-size: 11px !important;
    font-weight: bold;
    line-height: 1.2 !important;
    cursor: pointer;
    
    /* 渐变彩色背景 */
    background: linear-gradient(135deg, #6e8efb, #a777e3);
    color: white !important;
    
    border-radius: 3px;
    border: none;
    white-space: nowrap;
    vertical-align: baseline; /* 保持与标题文字对齐 */
    box-shadow: 0 1px 3px rgba(110, 142, 251, 0.3);
}

.libra-preview-btn:hover {
    filter: brightness(1.1);
    box-shadow: 0 2px 5px rgba(110, 142, 251, 0.5);
}

/* 遮罩层 */
#libra-preview-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 999998;
}

/* 弹窗容器 */
#libra-preview-modal {
    display: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 85vw;
    height: 85vh;
    background: #fff;
    z-index: 999999;
    flex-direction: column;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    overflow: hidden;
}

.libra-modal-header {
    padding: 10px 20px;
    background: #fdfdfd;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #eee;
}

.libra-modal-title { font-weight: bold; color: #555; font-size: 13px; }

.libra-close-btn {
    cursor: pointer;
    font-size: 12px;
    color: #999;
    padding: 2px 8px;
    border: 1px solid #eee;
    border-radius: 4px;
}

#libra-preview-iframe { flex: 1; width: 100%; border: none; }