Fix navbar across all pages: add nav include, fonts, active state, spacing, stats, error pages

- Add nav.php include to 5 missing pages (cost-calculator, thank-you, 403, 404, 500)
- Add ErrorDocument directives to .htaccess for custom 403/404/500 pages
- Fix bogus accuracy stats (homepage, web-scraping, location pages)
- Fix invisible CTA buttons on property and financial service pages
- Add Google Fonts (Roboto Slab + Lato) to all pages missing it (tools, blog articles, error pages)
- Add active nav link highlighting (teal underline for current page)
- Improve footer contrast to WCAG AA, equal-height cards, mobile text scaling
- Consistent navbar-to-content spacing across all pages
- Bump cache version to v1.1.3

includes/nav.php

@@ -1,3 +1,17 @@
+<?php
+$current_path = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
+$current_path = rtrim($current_path, '/');
+if ($current_path === '') $current_path = '/';
+
+function nav_active($href, $current) {
+    // Exact match
+    if ($href === $current) return ' active';
+    // Section match (e.g. /tools/ matches /tools/cost-calculator)
+    $href_trimmed = rtrim($href, '/');
+    if ($href_trimmed !== '' && $href_trimmed !== '/' && strpos($current, $href_trimmed) === 0) return ' active';
+    return '';
+}
+?>
 <!-- Navigation -->
 <nav class="navbar" id="navbar">
     <div class="nav-container">
@@ -10,14 +24,14 @@
             </a>
         </div>
         <div class="nav-menu" id="nav-menu">
-            <a href="/" class="nav-link">Home</a>
-            <a href="/#services" class="nav-link">Services</a>
-            <a href="/project-types" class="nav-link">Project Types</a>
-            <a href="/about" class="nav-link">About</a>
-            <a href="/tools/" class="nav-link">Free Tools</a>
-            <a href="/blog/" class="nav-link">Blog</a>
+            <a href="/" class="nav-link<?php echo $current_path === '/' ? ' active' : ''; ?>">Home</a>
+            <a href="/#services" class="nav-link<?php echo (strpos($current_path, '/services') === 0) ? ' active' : ''; ?>">Services</a>
+            <a href="/project-types" class="nav-link<?php echo nav_active('/project-types', $current_path); ?>">Project Types</a>
+            <a href="/about" class="nav-link<?php echo nav_active('/about', $current_path); ?>">About</a>
+            <a href="/tools/" class="nav-link<?php echo nav_active('/tools', $current_path); ?>">Free Tools</a>
+            <a href="/blog/" class="nav-link<?php echo nav_active('/blog', $current_path); ?>">Blog</a>
             <a href="/#contact" class="nav-link">Contact</a>
-            <a href="/quote" class="nav-link cta-button">Request Consultation</a>
+            <a href="/quote" class="nav-link cta-button<?php echo nav_active('/quote', $current_path); ?>">Request Consultation</a>
         </div>
         <button class="nav-toggle" id="nav-toggle" aria-expanded="false" aria-controls="nav-menu" aria-label="Toggle navigation menu">
             <span class="bar"></span>
@@ -25,4 +39,4 @@
             <span class="bar"></span>
         </button>
     </div>
-</nav>
+</nav>