(function() {
    // Create a new style element
    const style = document.createElement('style');
    // Give it an ID
    style.id = 'invert-colors-style';
    // Check if the style element exists
    if (document.getElementById('invert-colors-style')) {
        // If it exists, toggles effect off
        document.getElementById('invert-colors-style').remove();
    } else {
        // If it doesn't, add CSS rules for inverting colors
        style.textContent = `
            html {
                filter: invert(100%) hue-rotate(180deg);
            }
            // Apply inverse filter to media elements to revert to normal colors
            img, video, canvas {
                filter: invert(100%) hue-rotate(180deg);
            }
        `;
        // Add style element to the page
        document.head.appendChild(style);
    }
})();
```

(function() {
    // Get the current URL
    var url = encodeURIComponent(window.location.href);
    // Open the Wayback Machine's save page with the current URL
    window.open('https://web.archive.org/save/' + url, '_blank');
})();
```

javascript:(function(){
    var feeds = [];
    var links = document.getElementsByTagName('link');
    for (var i = 0; i < links.length; i++) {
        var link = links[i];
        var type = link.getAttribute('type');
        var rel = link.getAttribute('rel');
        var href = link.getAttribute('href');
        if (href && (type === 'application/rss+xml' || type === 'application/atom+xml' || (rel === 'alternate' && (type === 'application/rss+xml' || type === 'application/atom+xml')))) {
            if (href.indexOf('http') !== 0) {
                if (href.startsWith('/')) {
                    href = window.location.origin + href;
                } else {
                    href = window.location.href.substring(0, window.location.href.lastIndexOf('/') + 1) + href;
                }
            }
            feeds.push(href);
        }
    }
    if (feeds.length > 0) {
        // Open the first RSS feed in the browser's default RSS viewer
        window.open(feeds[0], '_blank');
    } else {
        // No RSS feed found, alert the user
        alert('No RSS feeds found on this page.');
    }
})();
```

(function() {
    function findWebmentionsEndpoint() {
        const linkTags = document.querySelectorAll('link[rel="webmention"]');
        if (linkTags.length > 0) {
            return linkTags[0].getAttribute('href');
        }  
        const headerLinks = document.querySelectorAll('a[rel="webmention"]');
        if (headerLinks.length > 0) {
            return headerLinks[0].getAttribute('href');
        }
        const headers = document.querySelector('meta[http-equiv="Link"]');
        if (headers) {
            const content = headers.getAttribute('content');
            const match = content.match(/<([^>]+)>;\s*rel=(?:%22|%27)webmention(?:%22|%27)/);
            if (match) {
                return match[1];
            }
        }
        return null;
    }
    const result = findWebmentionsEndpoint();
    alert(result || 'No webmentions endpoint found');
})();
```

                        
                            javascript:(function() {
                            // Find the main content area of the page
                            const main = document.querySelector('main');
                            // Check if the main tag exists
                            if (!main) {
                            alert('No main tag found on this page!');
                            return;
                            }
                            // Extract text content and trim whitespace
                            const text = main.textContent.trim();
                            // Split text into words and filter out empty strings
                            const words = text.split(/\s+/).filter(word => word.length > 0);
                            // Count the number of words
                            const wordCount = words.length;
                            // Define average reading speed (words per minute)
                            const avgReadingSpeed = 200;
                            // Calculate reading time in minutes
                            const readingTimeMinutes = wordCount / avgReadingSpeed;
                            // Convert to minutes and seconds
                            const mins = Math.floor(readingTimeMinutes);
                            const secs = Math.floor((readingTimeMinutes - mins) * 60);
                            // Format reading time as mm:ss
                            const readingTime = `${mins}:${secs.toString().padStart(2, '0')}`;
                            // Display the result
                            alert(`The main tag contains ${wordCount} words.
                            Estimated reading time: ${readingTime} mins`);
                            })();