/* ===== 关闭按钮 ===== */
.close-btn {
    background: none;
    border: none;
    color: #666;
    font-size: 18px;
    cursor: pointer;
    line-height: 1;
    padding: 4px;
}
.close-btn:hover {
    color: #333;
    background: rgba(0, 0, 0, 0.05);
    border-radius: 4px;
}
.close-btn.white { color: white; }
.close-btn.white:hover { background: rgba(255, 255, 255, 0.2); }