:root {
  /* Brand Colours */
  --color-midnight-navy: #14223C;
  --color-steel-blue: #30517C;
  --color-modern-taupe: #868072;
  --color-background: #F4F5F7;
  --color-white: #FFFFFF;
  --color-off-black: #1A1A1A;

  /* Typography */
  --font-heading: 'Montserrat', sans-serif;
  --font-body: 'Inter', sans-serif;

  /* Spacing system */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;
  
  /* Radii & Shadows */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --shadow-subtle: 0 4px 20px rgba(20, 34, 60, 0.05);
  --shadow-hover: 0 10px 30px rgba(20, 34, 60, 0.1);
  
  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background-color: var(--color-background);
  color: var(--color-off-black);
  line-height: 1.6;
  overflow-x: hidden;
}

/* Typography styles */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--color-midnight-navy);
  margin-bottom: var(--spacing-sm);
  font-weight: 700;
  line-height: 1.2;
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
}

h2 {
  font-size: clamp(2rem, 3.5vw, 3rem);
  font-weight: 600;
  color: var(--color-steel-blue);
}

h3 {
  font-size: 1.5rem;
}

p {
  font-size: 1.05rem;
  margin-bottom: var(--spacing-sm);
  color: var(--color-off-black);
  max-width: 70ch;
}

a {
  color: var(--color-steel-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-midnight-navy);
}

/* UI Components */
.btn {
  display: inline-block;
  padding: 1rem 2rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-weight: 600;
  letter-spacing: 0.5px;
  cursor: pointer;
  transition: all var(--transition-smooth);
  text-align: center;
}

.btn-primary {
  background-color: var(--color-midnight-navy);
  color: var(--color-white);
  border: 2px solid var(--color-midnight-navy);
}

.btn-primary:hover {
  background-color: transparent;
  color: var(--color-midnight-navy);
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-midnight-navy);
  border: 2px solid var(--color-midnight-navy);
}

.btn-secondary:hover {
  background-color: var(--color-midnight-navy);
  color: var(--color-white);
  transform: translateY(-2px);
}

/* Layout constraints */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: var(--spacing-sm) 0;
  z-index: 1000;
  transition: all var(--transition-smooth);
  background: transparent;
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-subtle);
  padding: calc(var(--spacing-sm) * 0.5) 0;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  position: relative;
  display: flex;
  align-items: center;
}

.nav-brand img,
.nav-brand svg {
  width: auto;
  transition: all var(--transition-smooth);
}

.nav-brand .logo-light {
  height: 72px;
  opacity: 1;
}

.nav-brand .logo-dark {
  position: absolute;
  left: 0;
  height: 72px;
  opacity: 0;
  pointer-events: none;
}

.navbar.scrolled .nav-brand .logo-light {
  height: 50px;
  opacity: 0;
}

.navbar.scrolled .nav-brand .logo-dark {
  height: 50px;
  opacity: 1;
}

.nav-links {
  display: flex;
  gap: var(--spacing-md);
  align-items: center;
}

.nav-links nav a {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  color: var(--color-midnight-navy);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-separator {
  color: var(--color-midnight-navy);
  margin: 0 calc(var(--spacing-md) / 2);
  font-weight: 300;
  opacity: 0.5;
  transition: color var(--transition-fast);
}

.navbar:not(.scrolled) .nav-links nav a,
.navbar:not(.scrolled) .nav-separator {
  color: var(--color-white);
}

.nav-links nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-steel-blue);
  transition: width var(--transition-fast);
}

.navbar:not(.scrolled) .nav-links nav a::after {
  background-color: var(--color-white);
}

.nav-links nav a:hover::after {
  width: 100%;
}

.mobile-menu-toggle {
  display: none;
  font-size: 1.5rem;
  color: var(--color-midnight-navy);
  cursor: pointer;
}

/* Sections */
section {
  padding: var(--spacing-xl) 0;
}

/* Hero Section */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: calc(80px + var(--spacing-lg));
  background-image: url('./assets/hero_background.png');
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
}

.hero::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(20, 34, 60, 0.85) 0%, rgba(48, 81, 124, 0.4) 100%);
  z-index: 1;
}

.hero .container {
  position: relative;
  z-index: 2;
}

.hero-content {
  max-width: 800px;
}

.hero-content h1, .hero-content p {
  color: var(--color-white);
}

.hero-content h1 {
  margin-bottom: var(--spacing-md);
  text-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.hero-content p {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-md);
  opacity: 0.9;
  font-weight: 300;
}

.hero-content .border-divider {
  width: 60px;
  height: 4px;
  background-color: var(--color-modern-taupe);
  margin-bottom: var(--spacing-md);
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-sm);
}

.hero-buttons .btn-primary:hover {
  background-color: var(--color-white);
  color: var(--color-midnight-navy);
  border-color: var(--color-white);
}

.hero-buttons .btn-secondary {
  color: var(--color-white);
  border-color: var(--color-white);
}

.hero-buttons .btn-secondary:hover {
  background-color: var(--color-white);
  color: var(--color-midnight-navy);
}

/* Services Section */
.bg-light {
  background-color: var(--color-white);
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-lg);
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.section-header h2 {
  margin-bottom: var(--spacing-xs);
}

.section-header .sub-marker {
  color: var(--color-modern-taupe);
  font-family: var(--font-heading);
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 0.85rem;
  font-weight: 600;
  display: block;
  margin-bottom: var(--spacing-sm);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-md);
}

.service-card {
  background: var(--color-background);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
  border-top: 4px solid transparent;
}

.service-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
  border-top-color: var(--color-steel-blue);
  background: var(--color-white);
}

.service-icon {
  width: 48px;
  height: 48px;
  margin-bottom: var(--spacing-sm);
  background: rgba(48, 81, 124, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--color-steel-blue);
}

.service-icon svg {
  width: 24px;
  height: 24px;
  stroke: currentColor;
  stroke-width: 2;
  fill: none;
}

/* Approach Section */
.approach-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.approach-item {
  text-align: center;
}

.approach-number {
  font-family: var(--font-heading);
  font-size: 3rem;
  font-weight: 700;
  color: var(--color-modern-taupe);
  opacity: 0.3;
  line-height: 1;
  margin-bottom: var(--spacing-xs);
}

.approach-item h3 {
  color: var(--color-midnight-navy);
  margin-bottom: var(--spacing-xs);
}

.approach-item p {
  margin: 0 auto;
}

/* CTA Section */
.cta-section {
  background-color: var(--color-midnight-navy);
  color: var(--color-white);
  text-align: center;
  padding: var(--spacing-xl) 0;
}

.cta-section h2 {
  color: var(--color-white);
}

.cta-section p {
  color: var(--color-white);
  opacity: 0.9;
  margin: 0 auto var(--spacing-md);
}

/* Footer */
footer {
  background-color: var(--color-off-black);
  color: var(--color-white);
  padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.footer-brand {
  max-width: 400px;
}

.footer-brand img {
  height: 40px;
  filter: brightness(0) invert(1);
  margin-bottom: var(--spacing-sm);
}

.footer-brand p {
  color: rgba(255, 255, 255, 0.7);
}

.footer-links h4 {
  color: var(--color-white);
  margin-bottom: var(--spacing-sm);
}

.footer-links ul {
  list-style: none;
}

.footer-links li {
  margin-bottom: var(--spacing-xs);
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
}

.footer-links a:hover {
  color: var(--color-modern-taupe);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.9rem;
}

/* Utilities */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 900px) {
  .approach-features {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
}

@media (max-width: 768px) {
  .nav-links nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--color-white);
    flex-direction: column;
    padding: var(--spacing-md) 0;
    box-shadow: var(--shadow-subtle);
  }

  .nav-links nav.active {
    display: flex;
  }

  .navbar:not(.scrolled) .nav-links nav.active a {
    color: var(--color-midnight-navy);
  }

  .navbar:not(.scrolled) .nav-links nav.active a::after {
    background-color: var(--color-midnight-navy);
  }

  .nav-links nav a {
    padding: var(--spacing-xs) var(--spacing-md);
  }

  .nav-separator {
    display: none;
  }

  .mobile-menu-toggle {
    display: block;
    color: var(--color-midnight-navy);
  }
  
  .navbar:not(.scrolled) .mobile-menu-toggle {
    color: var(--color-white);
  }

  .hero-buttons {
    flex-direction: column;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }
  
  .footer-bottom {
    flex-direction: column;
    gap: var(--spacing-sm);
    text-align: center;
  }
}