/* =================================================================
   CRITICAL CSS - Above-the-fold styles for initial page render
   ================================================================= */

/* CSS Reset and Normalize - CRITICAL */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{font-size:16px;scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;line-height:1.6;color:#1f2937;background-color:#fff;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}
img{max-width:100%;height:auto;display:block}
a{text-decoration:none;color:inherit}
ul,ol{list-style:none}
button{border:none;background:none;font-family:inherit;cursor:pointer}

/* CSS Custom Properties - CRITICAL */
:root{
--primary-blue:#1e3a8a;
--primary-blue-light:#3b82f6;
--primary-blue-dark:#1e40af;
--accent-blue:#60a5fa;
--gray-50:#f9fafb;
--gray-100:#f3f4f6;
--gray-200:#e5e7eb;
--gray-300:#d1d5db;
--gray-400:#9ca3af;
--gray-500:#6b7280;
--gray-600:#4b5563;
--gray-700:#374151;
--gray-800:#1f2937;
--gray-900:#111827;
--text-primary:#1f2937;
--text-secondary:#6b7280;
--text-light:#9ca3af;
--background-primary:#fff;
--background-secondary:#f9fafb;
--border-color:#e5e7eb;
--font-base:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;
--font-heading:Georgia,'Times New Roman',serif;
--text-xs:.75rem;
--text-sm:.875rem;
--text-base:1rem;
--text-lg:1.125rem;
--text-xl:1.25rem;
--text-2xl:1.5rem;
--text-3xl:1.875rem;
--text-4xl:2.25rem;
--text-5xl:3rem;
--spacing-xs:.25rem;
--spacing-sm:.5rem;
--spacing-md:1rem;
--spacing-lg:1.5rem;
--spacing-xl:2rem;
--spacing-2xl:3rem;
--spacing-3xl:4rem;
--container-max-width:1200px;
--border-radius:.5rem;
--border-radius-lg:.75rem;
--transition-fast:150ms ease-in-out;
--transition-base:250ms ease-in-out;
--transition-slow:350ms ease-in-out;
--shadow-sm:0 1px 2px 0 rgba(0,0,0,.05);
--shadow-base:0 1px 3px 0 rgba(0,0,0,.1),0 1px 2px 0 rgba(0,0,0,.06);
--shadow-md:0 4px 6px -1px rgba(0,0,0,.1),0 2px 4px -1px rgba(0,0,0,.06);
--shadow-lg:0 10px 15px -3px rgba(0,0,0,.1),0 4px 6px -2px rgba(0,0,0,.05);
--shadow-xl:0 20px 25px -5px rgba(0,0,0,.1),0 10px 10px -5px rgba(0,0,0,.04)
}

/* Accessibility - Visually Hidden but Screen Reader Accessible */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    margin: -1px;
    padding: 0;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Skip Link - Accessibility Enhancement */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-blue);
    color: var(--background-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    z-index: 10000;
    transition: top var(--transition-base);
    font-weight: 600;
    border-radius: 0 0 var(--border-radius) 0;
}

.skip-link:focus {
    top: 0;
    outline: 3px solid var(--accent-blue);
    outline-offset: 2px;
}

/* Container - CRITICAL */
.container{width:100%;max-width:var(--container-max-width);margin:0 auto;padding:0 var(--spacing-md)}

/* Typography - CRITICAL */
h1,h2,h3,h4,h5,h6{font-family:var(--font-heading);font-weight:700;line-height:1.2;color:var(--text-primary);margin-bottom:var(--spacing-md)}
h1{font-size:var(--text-4xl)}
h2{font-size:var(--text-3xl)}
h3{font-size:var(--text-2xl)}
h4{font-size:var(--text-xl)}
p{margin-bottom:var(--spacing-md)}

/* Header Styles - CRITICAL */
header{background-color:var(--background-primary);box-shadow:var(--shadow-sm);position:sticky;top:0;z-index:1000;transition:box-shadow var(--transition-base)}
.header-content{display:flex;justify-content:space-between;align-items:center;padding:var(--spacing-md) 0}
.logo{display:flex;align-items:center;gap:var(--spacing-sm)}
.logo img{width:auto;height:40px}
.logo-text{font-size:var(--text-lg);font-weight:700;color:var(--primary-blue)}

/* Focus Styles for Keyboard Navigation - Accessibility Enhancement */
a:focus,
button:focus,
input:focus,
select:focus,
textarea:focus,
[tabindex]:focus {
    outline: 3px solid var(--accent-blue);
    outline-offset: 2px;
}

a:focus:not(:focus-visible),
button:focus:not(:focus-visible),
input:focus:not(:focus-visible),
select:focus:not(:focus-visible),
textarea:focus:not(:focus-visible),
[tabindex]:focus:not(:focus-visible) {
    outline: none;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
    outline: 3px solid var(--accent-blue);
    outline-offset: 2px;
}

/* Navigation - CRITICAL */
nav{position:relative}
.mobile-menu-toggle{display:none;flex-direction:column;gap:4px;padding:var(--spacing-sm);cursor:pointer;border-radius:var(--border-radius);transition:background-color var(--transition-base)}
.mobile-menu-toggle:hover{background-color:var(--gray-100)}
.mobile-menu-toggle:focus{outline:3px solid var(--accent-blue);outline-offset:2px}
.hamburger,.hamburger::before,.hamburger::after{width:24px;height:2px;background-color:var(--text-primary);transition:all var(--transition-base)}
.hamburger{position:relative}
.hamburger::before,.hamburger::after{content:'';position:absolute;left:0}
.hamburger::before{top:-8px}
.hamburger::after{top:8px}
.nav-menu{display:flex;gap:var(--spacing-xl);align-items:center}
.nav-menu li a{color:var(--text-secondary);font-weight:500;font-size:var(--text-base);padding:var(--spacing-sm) 0;position:relative;transition:color var(--transition-base);border-radius:var(--border-radius)}
.nav-menu li a::after{content:'';position:absolute;bottom:0;left:0;width:0;height:2px;background-color:var(--primary-blue);transition:width var(--transition-base)}
.nav-menu li a:hover,.nav-menu li a:focus{color:var(--primary-blue)}
.nav-menu li a:hover::after,.nav-menu li a:focus::after{width:100%}

/* Hero Section - CRITICAL */
.hero{position:relative;min-height:600px;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,var(--primary-blue) 0%,var(--primary-blue-dark) 100%);color:var(--background-primary);padding:var(--spacing-3xl) 0;overflow:hidden}
.hero-background{position:absolute;top:0;left:0;width:100%;height:100%;background-image:url('images/hero-bg.jpg');background-size:cover;background-position:center;opacity:.15;z-index:0}
.hero-content{position:relative;z-index:1;text-align:center;max-width:800px;margin:0 auto}
.hero h1{color:var(--background-primary);font-size:var(--text-5xl);margin-bottom:var(--spacing-lg);text-shadow:0 2px 4px rgba(0,0,0,.3)}
.hero-subtitle{font-size:var(--text-xl);margin-bottom:var(--spacing-2xl);color:var(--gray-100);line-height:1.8}
.hero-cta{display:flex;gap:var(--spacing-md);justify-content:center;flex-wrap:wrap}

/* Buttons - CRITICAL with Enhanced Focus Styles */
.btn{display:inline-flex;align-items:center;justify-content:center;padding:var(--spacing-md) var(--spacing-xl);font-size:var(--text-base);font-weight:600;border-radius:var(--border-radius);transition:all var(--transition-base);cursor:pointer;text-align:center;white-space:nowrap;border:2px solid transparent}
.btn:focus{outline:3px solid var(--accent-blue);outline-offset:3px}
.btn-primary{background-color:var(--background-primary);color:var(--primary-blue);box-shadow:var(--shadow-md);border-color:var(--background-primary)}
.btn-primary:hover,.btn-primary:focus{background-color:var(--gray-100);transform:translateY(-2px);box-shadow:var(--shadow-lg)}
.btn-secondary{background-color:transparent;color:var(--background-primary);border:2px solid var(--background-primary)}
.btn-secondary:hover,.btn-secondary:focus{background-color:var(--background-primary);color:var(--primary-blue)}
.btn-small{padding:var(--spacing-sm) var(--spacing-lg);font-size:var(--text-sm)}
.btn-block{width:100%}

/* =================================================================
   END CRITICAL CSS
   Below-the-fold styles loaded after initial render
   ================================================================= */

/* Section Styles */
section{padding:var(--spacing-3xl) 0}
.section-header{text-align:center;margin-bottom:var(--spacing-3xl)}
.section-subtitle{color:var(--text-secondary);font-size:var(--text-lg);margin-top:var(--spacing-sm)}

/* About Section */
.about{background-color:var(--background-secondary)}
.about-content{display:grid;grid-template-columns:1fr;gap:var(--spacing-3xl)}
.about-text h3{color:var(--primary-blue);margin-top:var(--spacing-xl);margin-bottom:var(--spacing-md)}
.about-text h3:first-child{margin-top:0}
.about-text p{color:var(--text-secondary);line-height:1.8}
.about-features{display:grid;grid-template-columns:1fr;gap:var(--spacing-xl)}
.feature-card{background-color:var(--background-primary);padding:var(--spacing-xl);border-radius:var(--border-radius-lg);box-shadow:var(--shadow-base);transition:transform var(--transition-base),box-shadow var(--transition-base);will-change:transform;border:2px solid transparent}
.feature-card:hover,.feature-card:focus-within{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:var(--accent-blue)}
.feature-icon{color:var(--primary-blue);margin-bottom:var(--spacing-md)}
.feature-card h4{color:var(--primary-blue);margin-bottom:var(--spacing-sm)}
.feature-card p{color:var(--text-secondary);line-height:1.7;margin-bottom:0}

/* Products Section - Optimized for performance */
.products{background-color:var(--background-primary)}
.products-grid{display:grid;grid-template-columns:1fr;gap:var(--spacing-2xl)}
.product-card{background-color:var(--background-primary);border-radius:var(--border-radius-lg);overflow:hidden;box-shadow:var(--shadow-base);transition:transform var(--transition-base),box-shadow var(--transition-base),border-color var(--transition-base);border:2px solid var(--border-color);will-change:transform}
.product-card:hover,.product-card:focus-within{transform:translateY(-6px) translateZ(0);box-shadow:var(--shadow-xl);border-color:var(--primary-blue-light)}
.product-image{position:relative;overflow:hidden;aspect-ratio:4/3;background-color:var(--gray-100)}
.product-image img{width:100%;height:100%;object-fit:cover;transition:transform var(--transition-slow);backface-visibility:hidden}
.product-image img[loading="lazy"]{opacity:0;transition:opacity .3s ease-in-out,transform var(--transition-slow)}
.product-image img[loading="lazy"].loaded{opacity:1}
.product-card:hover .product-image img,.product-card:focus-within .product-image img{transform:scale(1.08) translateZ(0)}
.product-badge{position:absolute;top:var(--spacing-md);right:var(--spacing-md);background-color:var(--primary-blue);color:var(--background-primary);padding:var(--spacing-xs) var(--spacing-md);border-radius:var(--border-radius);font-size:var(--text-sm);font-weight:600;z-index:10;box-shadow:var(--shadow-md)}
.product-info{padding:var(--spacing-xl)}
.product-info h3{color:var(--text-primary);margin-bottom:var(--spacing-sm);font-size:var(--text-xl)}
.product-description{color:var(--text-secondary);font-size:var(--text-base);line-height:1.7;margin-bottom:var(--spacing-lg)}
.product-details{display:flex;justify-content:space-between;align-items:center;margin-top:var(--spacing-lg)}
.product-price{font-size:var(--text-2xl);font-weight:700;color:var(--primary-blue)}

/* Optimized shimmer loading animation */
.product-image::before{content:'';position:absolute;top:0;left:0;width:100%;height:100%;background:linear-gradient(90deg,var(--gray-200) 0%,var(--gray-100) 50%,var(--gray-200) 100%);background-size:200% 100%;animation:shimmer 1.5s infinite;z-index:1}
.product-image img.loaded~.product-image::before,.product-image img:not([loading="lazy"])~.product-image::before{display:none}
@keyframes shimmer{0%{background-position:200% 0}100%{background-position:-200% 0}}

/* Contact Section */
.contact{background-color:var(--background-secondary)}
.contact-content{display:grid;grid-template-columns:1fr;gap:var(--spacing-3xl)}
.contact-info{display:flex;flex-direction:column;gap:var(--spacing-xl)}
.contact-item{display:flex;gap:var(--spacing-lg);align-items:flex-start}
.contact-icon{flex-shrink:0;width:48px;height:48px;display:flex;align-items:center;justify-content:center;background-color:var(--primary-blue);color:var(--background-primary);border-radius:var(--border-radius)}
.contact-details h3{font-size:var(--text-lg);margin-bottom:var(--spacing-xs)}
.contact-details p,.contact-details address{color:var(--text-secondary);font-style:normal;line-height:1.8}
.contact-details a{color:var(--primary-blue);transition:color var(--transition-base);border-radius:var(--border-radius)}
.contact-details a:hover,.contact-details a:focus{color:var(--primary-blue-light);text-decoration:underline}
.contact-note{font-size:var(--text-sm);color:var(--text-light)}
.hours-list{display:grid;grid-template-columns:auto 1fr;gap:var(--spacing-xs) var(--spacing-md)}
.hours-list dt{font-weight:600;color:var(--text-primary)}
.hours-list dd{color:var(--text-secondary)}

/* Contact Form - Optimized */
.contact-form-container{background-color:var(--background-primary);padding:var(--spacing-2xl);border-radius:var(--border-radius-lg);box-shadow:var(--shadow-base)}
.contact-form{display:flex;flex-direction:column;gap:var(--spacing-lg)}
.form-group{display:flex;flex-direction:column;gap:var(--spacing-xs)}
.form-group label{font-weight:600;color:var(--text-primary);font-size:var(--text-base)}
.required{color:#ef4444}
.form-group input,.form-group select,.form-group textarea{padding:var(--spacing-md);border:2px solid var(--border-color);border-radius:var(--border-radius);font-size:var(--text-base);font-family:inherit;transition:border-color var(--transition-base),box-shadow var(--transition-base);background-color:var(--background-primary)}
.form-group input:hover,.form-group select:hover,.form-group textarea:hover{border-color:var(--gray-400)}
.form-group input:focus,.form-group select:focus,.form-group textarea:focus{outline:none;border-color:var(--primary-blue);box-shadow:0 0 0 3px rgba(30,58,138,.1)}
.form-group textarea{resize:vertical;min-height:120px}
.form-group select{cursor:pointer}
.contact-form-container h3{font-size:var(--text-xl);margin-bottom:var(--spacing-lg);color:var(--text-primary)}

/* Contact Map - Lazy loaded */
.contact-map{margin-top:var(--spacing-xl)}
.contact-map h3{font-size:var(--text-lg);margin-bottom:var(--spacing-md);color:var(--text-primary)}
.map-container{position:relative;width:100%;padding-bottom:75%;height:0;overflow:hidden;border-radius:var(--border-radius-lg);box-shadow:var(--shadow-base)}
.map-container iframe{position:absolute;top:0;left:0;width:100%;height:100%;border-radius:var(--border-radius-lg)}

/* Form Validation States */
.form-group.has-error input,.form-group.has-error select,.form-group.has-error textarea{border-color:#ef4444}
.form-group .error-message{color:#ef4444;font-size:var(--text-sm);margin-top:var(--spacing-xs);display:block}

/* Success Message - Optimized animation */
.success-message{background-color:#10b981;color:var(--background-primary);padding:var(--spacing-md);border-radius:var(--border-radius);margin-bottom:var(--spacing-lg);text-align:center;font-weight:600;animation:slideDown .3s ease-in-out}
@keyframes slideDown{from{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}

/* Button States - Optimized */
.btn-primary:active{transform:translateY(0);box-shadow:var(--shadow-md)}
.btn-primary:disabled{opacity:.6;cursor:not-allowed;transform:none}

/* Footer */
footer{background-color:var(--gray-900);color:var(--gray-300);padding:var(--spacing-3xl) 0 var(--spacing-xl)}
.footer-content{display:grid;grid-template-columns:1fr;gap:var(--spacing-2xl);margin-bottom:var(--spacing-2xl)}
.footer-section h3{color:var(--background-primary);font-size:var(--text-lg);margin-bottom:var(--spacing-lg)}
.footer-section p{line-height:1.8;margin-bottom:var(--spacing-lg)}
.social-links{display:flex;gap:var(--spacing-md)}
.social-links a{display:flex;align-items:center;justify-content:center;width:40px;height:40px;background-color:var(--gray-800);border-radius:var(--border-radius);transition:background-color var(--transition-base),transform var(--transition-base)}
.social-links a:hover,.social-links a:focus{background-color:var(--primary-blue);transform:translateY(-2px)}
.footer-links,.footer-contact{display:flex;flex-direction:column;gap:var(--spacing-sm)}
.footer-links a,.footer-contact a{color:var(--gray-300);transition:color var(--transition-base);border-radius:var(--border-radius);padding:var(--spacing-xs) 0}
.footer-links a:hover,.footer-contact a:hover,.footer-links a:focus,.footer-contact a:focus{color:var(--primary-blue-light);text-decoration:underline}
.footer-bottom{padding-top:var(--spacing-xl);border-top:1px solid var(--gray-800);display:flex;flex-direction:column;gap:var(--spacing-md);align-items:center;text-align:center}
.copyright{color:var(--gray-400);font-size:var(--text-sm);margin:0}
.footer-legal{display:flex;flex-wrap:wrap;gap:var(--spacing-md);justify-content:center}
.footer-legal a{color:var(--gray-400);font-size:var(--text-sm);transition:color var(--transition-base);padding:var(--spacing-xs);border-radius:var(--border-radius)}
.footer-legal a:hover,.footer-legal a:focus{color:var(--primary-blue-light);text-decoration:underline}

/* Responsive Design - Mobile-First Tablet (min-width: 640px) */
@media (min-width:640px){
:root{--text-4xl:2.5rem;--text-5xl:3.5rem}
.container{padding:0 var(--spacing-xl)}
.about-features{grid-template-columns:repeat(2,1fr)}
.products-grid{grid-template-columns:repeat(2,1fr);gap:var(--spacing-xl)}
.footer-content{grid-template-columns:repeat(2,1fr)}
}

/* Tablet Landscape (min-width: 768px) */
@media (min-width:768px){
.header-content{padding:var(--spacing-lg) 0}
.logo img{height:50px}
.about-content{grid-template-columns:1fr 1fr;align-items:start}
.contact-content{grid-template-columns:1fr 1fr}
.footer-bottom{flex-direction:row;justify-content:space-between;text-align:left}
}

/* Desktop (min-width: 1024px) */
@media (min-width:1024px){
:root{--text-5xl:4rem}
.hero{min-height:700px}
.about-features{grid-template-columns:repeat(3,1fr)}
.products-grid{grid-template-columns:repeat(3,1fr);gap:var(--spacing-2xl)}
.footer-content{grid-template-columns:repeat(4,1fr)}
}

/* Large Desktop (min-width: 1280px) */
@media (min-width:1280px){
.container{padding:0 var(--spacing-2xl)}
.products-grid{grid-template-columns:repeat(4,1fr)}
}

/* Mobile Menu - Max-width: 767px */
@media (max-width:767px){
.mobile-menu-toggle{display:flex}
.nav-menu{position:absolute;top:100%;right:0;background-color:var(--background-primary);flex-direction:column;width:250px;padding:var(--spacing-lg);box-shadow:var(--shadow-lg);border-radius:var(--border-radius);margin-top:var(--spacing-sm);transform:translateX(100%);opacity:0;visibility:hidden;transition:all var(--transition-base)}
.nav-menu.active{transform:translateX(0);opacity:1;visibility:visible}
.nav-menu li{width:100%}
.nav-menu li a{display:block;padding:var(--spacing-md)}
.hero h1{font-size:var(--text-3xl)}
.hero-subtitle{font-size:var(--text-lg)}
.hero-cta{flex-direction:column;align-items:stretch}
.btn{width:100%}
.products-grid{gap:var(--spacing-xl)}
.product-card{margin:0 auto;max-width:400px}
}

/* Performance Optimizations - Reduced motion support */
@media (prefers-reduced-motion:reduce){
*,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important;scroll-behavior:auto!important}
.skip-link:focus{transition:none}
}

/* High Contrast Mode Support - Accessibility Enhancement */
@media (prefers-contrast:high){
:root{
--border-color:#000;
--text-primary:#000;
--text-secondary:#000;
--background-primary:#fff;
--primary-blue:#0000cc;
}
.btn{border:2px solid currentColor}
.product-card{border:3px solid var(--text-primary)}
.feature-card{border:2px solid var(--text-primary)}
a:focus,button:focus,input:focus,select:focus,textarea:focus{outline:4px solid #000;outline-offset:3px}
}

/* Dark Mode Support */
@media (prefers-color-scheme:dark){
:root{
--text-primary:#f3f4f6;
--text-secondary:#d1d5db;
--text-light:#9ca3af;
--background-primary:#1f2937;
--background-secondary:#111827;
--border-color:#374151;
--gray-900:#f9fafb;
--gray-800:#f3f4f6;
--gray-700:#e5e7eb;
--gray-600:#d1d5db;
--gray-500:#9ca3af;
--gray-400:#6b7280;
--gray-300:#4b5563;
--gray-200:#374151;
--gray-100:#1f2937;
--gray-50:#111827;
}
.hero-background{opacity:.3}
}

/* Print Styles - Optimized */
@media print{
*,*::before,*::after{background:transparent!important;color:#000!important;box-shadow:none!important;text-shadow:none!important}
header,footer,.hero-cta,.contact-form-container,.mobile-menu-toggle,.skip-link{display:none!important}
body{color:#000;background:#fff;font-size:12pt;line-height:1.5}
h1,h2,h3,h4,h5,h6{page-break-after:avoid;page-break-inside:avoid}
p,ul,ol{orphans:3;widows:3}
a{text-decoration:underline;word-wrap:break-word}
a[href^="http"]:after{content:" (" attr(href) ")"}
img{max-width:100%!important;page-break-inside:avoid}
.product-card{page-break-inside:avoid;border:1px solid #000;margin-bottom:1cm}
.container{max-width:100%;padding:0}
section{padding:1cm 0}
.hero{min-height:auto;padding:2cm 0}
.hero h1{color:#000!important;text-shadow:none!important;font-size:24pt}
.products-grid{grid-template-columns:repeat(2,1fr);gap:1cm}
.about-content{grid-template-columns:1fr}
}

/* Cross-Browser Compatibility Fixes */
/* Firefox specific fixes */
@-moz-document url-prefix(){
.product-image img{image-rendering:-moz-crisp-edges}
}

/* Safari/WebKit specific fixes */
@supports (-webkit-appearance:none){
input[type="text"],input[type="email"],input[type="tel"],select,textarea{-webkit-appearance:none;-moz-appearance:none;appearance:none}
}

/* Edge/IE specific fixes */
@supports (-ms-ime-align:auto){
.product-card{transform:none}
.feature-card{transform:none}
}

/* Text Zoom Support - Ensure readable at 200% zoom */
@media screen and (min-width:768px){
html{font-size:calc(16px + 0.2vw)}
}

/* Ensure focus indicators work in all browsers */
*:focus {
    outline-width: 3px;
    outline-style: solid;
    outline-color: var(--accent-blue);
}

/* Enhanced keyboard navigation support */
[role="button"]:focus,
[role="menuitem"]:focus,
[role="link"]:focus {
    outline: 3px solid var(--accent-blue);
    outline-offset: 2px;
}