:root {
    --clr-slate-900: #0f172a;
    --clr-slate-800: #1e293b;
    --clr-slate-700: #334155;
    --clr-slate-600: #475569;
    --clr-slate-100: #f1f5f9;
    --clr-slate-50: #f8fafc;
    
    --clr-wood-600: #d97706;
    --clr-wood-500: #f59e0b;
    --clr-wood-800: #92400e;
    
    --clr-bg: var(--clr-slate-50);
    --clr-surface: #ffffff;
    --clr-text: var(--clr-slate-700);
    --clr-heading: var(--clr-slate-900);
    --clr-border: var(--clr-slate-100);
    
    --font-sans: 'Outfit', system-ui, -apple-system, sans-serif;
    
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 8rem;
    
    --container-width: 1200px;
    --header-height: 80px;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }
body { 
    line-height: 1.6; 
    -webkit-font-smoothing: antialiased; 
    font-family: var(--font-sans);
    color: var(--clr-text);
    background-color: var(--clr-bg);
    overflow-x: hidden;
}
img, picture, video, canvas, svg { display: block; max-width: 100%; height: auto; }
input, button, textarea, select { font: inherit; }
p, h1, h2, h3, h4, h5, h6 { overflow-wrap: break-word; }

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--clr-heading);
    line-height: 1.1;
    font-weight: 700;
}
h1 { font-size: clamp(2.5rem, 5vw, 4.5rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(2rem, 4vw, 3rem); letter-spacing: -0.01em; }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: 1.25rem; }
p { font-size: 1.125rem; margin-bottom: 1.5rem; max-width: 70ch; }
.lead { font-size: 1.25rem; color: var(--clr-slate-600); font-weight: 300; }

a { color: inherit; text-decoration: none; }

/* Structural Elements */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--space-sm);
}

section {
    padding: var(--space-xl) 0;
}

/* Layout Utilities */
.grid { display: grid; }
.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }

.grid-cols-2 { grid-template-columns: 1fr; }
.grid-cols-3 { grid-template-columns: 1fr; }
.grid-cols-4 { grid-template-columns: 1fr; }

@media (min-width: 768px) {
    .grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
    .grid-cols-3 { grid-template-columns: repeat(2, 1fr); }
    .grid-cols-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
    .grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
    .grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
}

/* Header & Nav */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--clr-border);
    height: var(--header-height);
    display: flex;
    align-items: center;
}
.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--clr-slate-900);
    letter-spacing: -0.05em;
    text-transform: uppercase;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.logo span { color: var(--clr-wood-600); }

.nav-links {
    display: none;
    list-style: none;
    gap: 2rem;
}
.nav-links a {
    font-weight: 600;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--clr-slate-700);
    transition: color 0.2s;
}
.nav-links a:hover, .nav-links a.active {
    color: var(--clr-wood-600);
}

.mobile-nav-toggle {
    display: block;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}
.mobile-nav-toggle span {
    display: block;
    width: 25px;
    height: 2px;
    background-color: var(--clr-slate-900);
    margin: 5px 0;
    transition: 0.3s;
}

@media (min-width: 1024px) {
    .nav-links { display: flex; }
    .mobile-nav-toggle { display: none; }
}

/* Mobile Nav Overlay */
.mobile-nav-overlay {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--clr-surface);
    z-index: 99;
    padding: var(--space-md);
    transform: translateX(100%);
    transition: transform 0.3s ease-in-out;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}
.mobile-nav-overlay.active {
    transform: translateX(0);
}
.mobile-nav-overlay a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--clr-slate-900);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    transition: all 0.2s;
    cursor: pointer;
    border: 2px solid transparent;
}
.btn-primary {
    background-color: var(--clr-wood-600);
    color: white;
}
.btn-primary:hover {
    background-color: var(--clr-wood-800);
}
.btn-outline {
    background-color: transparent;
    border-color: var(--clr-slate-900);
    color: var(--clr-slate-900);
}
.btn-outline:hover {
    background-color: var(--clr-slate-900);
    color: white;
}
.btn-light {
    background-color: white;
    color: var(--clr-slate-900);
}
.btn-light:hover {
    background-color: var(--clr-slate-100);
}

/* Hero Sections */
.hero {
    position: relative;
    padding: calc(var(--space-xl) + 2rem) 0;
    background-color: var(--clr-slate-900);
    color: white;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(to right, rgba(15, 23, 42, 0.9), rgba(15, 23, 42, 0.4));
    z-index: 1;
}
.hero-img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 0;
}
.hero .container {
    position: relative;
    z-index: 2;
}
.hero h1 {
    color: white;
    max-width: 15ch;
    margin-bottom: var(--space-md);
}
.hero p {
    color: var(--clr-slate-100);
    font-size: 1.25rem;
}

/* Specific Niche Sections */
/* Architectural Blueprint Background */
.bg-blueprint {
    background-color: var(--clr-slate-900);
    background-image: 
        linear-gradient(rgba(255,255,255,0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.05) 1px, transparent 1px);
    background-size: 50px 50px;
    color: white;
}
.bg-blueprint h2, .bg-blueprint h3 { color: white; }
.bg-blueprint p { color: var(--clr-slate-100); }

/* Structural Cards */
.card {
    background: var(--clr-surface);
    border: 1px solid var(--clr-border);
    padding: var(--space-md);
    transition: transform 0.3s, box-shadow 0.3s;
    position: relative;
}
.card::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background-color: var(--clr-wood-600);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s;
}
.card:hover::after {
    transform: scaleX(1);
}
.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}
.card-img {
    width: 100%;
    height: 250px;
    object-fit: cover;
    margin-bottom: var(--space-sm);
    background-color: var(--clr-slate-100);
}
.card-title {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

/* Service Details Layout */
.service-header {
    padding: var(--space-xl) 0;
    background-color: var(--clr-slate-100);
    border-bottom: 1px solid var(--clr-border);
}
.service-content {
    display: grid;
    gap: var(--space-lg);
}
@media (min-width: 1024px) {
    .service-content {
        grid-template-columns: 2fr 1fr;
    }
}
.sidebar {
    background-color: var(--clr-slate-50);
    padding: var(--space-md);
    border: 1px solid var(--clr-border);
    align-self: start;
    position: sticky;
    top: calc(var(--header-height) + var(--space-md));
}
.sidebar-list {
    list-style: none;
}
.sidebar-list li {
    margin-bottom: 0.5rem;
}
.sidebar-list a {
    display: block;
    padding: 0.75rem 1rem;
    background-color: var(--clr-surface);
    border: 1px solid var(--clr-border);
    font-weight: 600;
    transition: all 0.2s;
}
.sidebar-list a:hover, .sidebar-list a.active {
    background-color: var(--clr-wood-600);
    color: white;
    border-color: var(--clr-wood-600);
}

/* Process Steps */
.process-steps {
    list-style: none;
    counter-reset: process-counter;
}
.process-step {
    position: relative;
    padding-left: 4rem;
    margin-bottom: var(--space-md);
}
.process-step::before {
    counter-increment: process-counter;
    content: counter(process-counter);
    position: absolute;
    left: 0;
    top: 0;
    width: 3rem;
    height: 3rem;
    background-color: var(--clr-slate-900);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
    border-radius: 50%;
}
.process-step::after {
    content: '';
    position: absolute;
    left: 1.5rem;
    top: 3.5rem;
    bottom: -1rem;
    width: 2px;
    background-color: var(--clr-slate-100);
}
.process-step:last-child::after {
    display: none;
}

/* Image Grid */
.masonry-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    grid-auto-rows: 10px;
    gap: var(--space-sm);
}
.masonry-item {
    width: 100%;
}
.masonry-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 4px;
}
.span-2 { grid-row-end: span 30; }
.span-3 { grid-row-end: span 45; }

/* Contact Form */
.form-group {
    margin-bottom: 1.5rem;
}
.form-label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--clr-slate-900);
}
.form-control {
    width: 100%;
    padding: 1rem;
    border: 1px solid var(--clr-slate-600);
    background-color: var(--clr-surface);
    font-family: var(--font-sans);
    transition: border-color 0.2s;
}
.form-control:focus {
    outline: none;
    border-color: var(--clr-wood-600);
    box-shadow: 0 0 0 3px rgba(217, 119, 6, 0.1);
}

/* Footer */
.site-footer {
    background-color: var(--clr-slate-900);
    color: var(--clr-slate-100);
    padding: var(--space-xl) 0 var(--space-md);
}
.site-footer h4 {
    color: white;
    margin-bottom: 1.5rem;
}
.footer-links {
    list-style: none;
}
.footer-links li {
    margin-bottom: 0.75rem;
}
.footer-links a {
    color: var(--clr-slate-100);
    transition: color 0.2s;
}
.footer-links a:hover {
    color: var(--clr-wood-500);
}
.footer-bottom {
    margin-top: var(--space-lg);
    padding-top: var(--space-md);
    border-top: 1px solid rgba(255,255,255,0.1);
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
    color: var(--clr-slate-600);
}

/* Feature highlight */
.highlight-box {
    background-color: var(--clr-wood-600);
    color: white;
    padding: var(--space-lg);
}
.highlight-box h2, .highlight-box h3 { color: white; }

/* Trust Badges */
.trust-badges {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
    align-items: center;
    margin-top: var(--space-md);
}
.badge {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    color: var(--clr-slate-900);
    background: var(--clr-slate-100);
    padding: 0.5rem 1rem;
    border-radius: 4px;
}

/* Responsive utilities */
@media (max-width: 767px) {
    .hide-on-mobile { display: none !important; }
    .text-center-mobile { text-align: center; }
}