:root {
  /* Material-driven color palette */
  --color-dark-walnut: #3A2F2A;
  --color-warm-oak: #B89B72;
  --color-soft-linen: #EFE9E2;
  --color-brushed-steel: #8C8F8E;
  --color-aged-brass: #C2A46D;
  
  /* Typography */
  --font-serif: 'Georgia', 'Times New Roman', serif;
  --font-sans: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  
  /* Spacing (craft-inspired) */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;
  
  /* Transitions */
  --transition-smooth: 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-dark-walnut);
  background-color: var(--color-soft-linen);
  line-height: 1.7;
  font-size: 1rem;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: var(--spacing-sm);
}

h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
}

h2 {
  font-size: clamp(1.5rem, 4vw, 2.5rem);
}

h3 {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
}

p {
  margin-bottom: var(--spacing-sm);
  max-width: 65ch;
}

a {
  color: var(--color-dark-walnut);
  text-decoration: none;
  transition: color var(--transition-smooth);
}

a:hover {
  color: var(--color-warm-oak);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Header */
header {
  background-color: var(--color-dark-walnut);
  color: var(--color-soft-linen);
  padding: var(--spacing-sm) var(--spacing-md);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--color-soft-linen);
}

.logo:hover {
  color: var(--color-warm-oak);
}

nav ul {
  list-style: none;
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

nav a {
  color: var(--color-soft-linen);
  font-size: 0.95rem;
  letter-spacing: 0.5px;
}

nav a:hover {
  color: var(--color-warm-oak);
}

.burger-menu {
  display: none;
  background: none;
  border: none;
  color: var(--color-soft-linen);
  font-size: 1.5rem;
  cursor: pointer;
  padding: var(--spacing-xs);
}

/* Main content */
main {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--spacing-md);
}

/* Hero section */
.hero {
  min-height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-dark-walnut) 0%, var(--color-brushed-steel) 100%);
  color: var(--color-soft-linen);
  padding: var(--spacing-xl) var(--spacing-md);
  margin: var(--spacing-md) 0;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    repeating-linear-gradient(45deg, transparent, transparent 2px, rgba(255,255,255,0.03) 2px, rgba(255,255,255,0.03) 4px);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 800px;
}

.hero h1 {
  color: var(--color-soft-linen);
  margin-bottom: var(--spacing-md);
}

.hero p {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-soft-linen);
  opacity: 0.95;
  max-width: 100%;
}

/* Section styles */
.section {
  margin: var(--spacing-xl) 0;
  padding: var(--spacing-lg) 0;
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  margin-bottom: var(--spacing-md);
  color: var(--color-dark-walnut);
  position: relative;
  padding-left: var(--spacing-md);
  border-left: 4px solid var(--color-warm-oak);
}

/* Grid layouts */
.grid {
  display: grid;
  gap: var(--spacing-md);
  margin: var(--spacing-md) 0;
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

/* Card styles */
.card {
  background-color: white;
  padding: var(--spacing-md);
  border: 1px solid rgba(58, 47, 42, 0.1);
  transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}

.card img {
  width: 100%;
  height: 250px;
  object-fit: cover;
  margin-bottom: var(--spacing-sm);
}

/* Asymmetric layouts */
.asymmetric-layout {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--spacing-lg);
  align-items: start;
}

.asymmetric-layout.reverse {
  grid-template-columns: 2fr 1fr;
}

/* Vertical composition blocks */
.vertical-block {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.vertical-block img {
  width: 100%;
  height: auto;
  border: 1px solid rgba(58, 47, 42, 0.1);
}

/* Technical layout */
.technical-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-md);
  margin: var(--spacing-md) 0;
}

.technical-item {
  padding: var(--spacing-md);
  background: white;
  border-left: 3px solid var(--color-warm-oak);
}

/* Diagram-style presentation */
.diagram-container {
  background: white;
  padding: var(--spacing-lg);
  margin: var(--spacing-md) 0;
  border: 2px solid var(--color-dark-walnut);
}

.diagram-item {
  margin: var(--spacing-md) 0;
  padding: var(--spacing-sm);
  border-bottom: 1px solid var(--color-soft-linen);
}

/* Gallery grid */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-md);
  margin: var(--spacing-md) 0;
}

.gallery-item {
  position: relative;
  overflow: hidden;
  aspect-ratio: 4/3;
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-smooth);
}

.gallery-item:hover img {
  transform: scale(1.05);
}

/* Contact form */
.contact-form {
  max-width: 600px;
  margin: var(--spacing-md) auto;
  background: white;
  padding: var(--spacing-lg);
  border: 1px solid rgba(58, 47, 42, 0.1);
}

.form-group {
  margin-bottom: var(--spacing-md);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-xs);
  font-weight: 500;
  color: var(--color-dark-walnut);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: var(--spacing-sm);
  border: 1px solid var(--color-brushed-steel);
  background-color: var(--color-soft-linen);
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--color-dark-walnut);
  transition: border-color var(--transition-smooth);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--color-warm-oak);
}

.form-group textarea {
  min-height: 150px;
  resize: vertical;
}

.checkbox-group {
  display: flex;
  align-items: start;
  gap: var(--spacing-xs);
  margin: var(--spacing-md) 0;
}

.checkbox-group input[type="checkbox"] {
  width: auto;
  margin-top: 4px;
}

.btn {
  display: inline-block;
  padding: var(--spacing-sm) var(--spacing-md);
  background-color: var(--color-dark-walnut);
  color: var(--color-soft-linen);
  border: none;
  font-family: var(--font-sans);
  font-size: 1rem;
  cursor: pointer;
  transition: background-color var(--transition-smooth);
  letter-spacing: 0.5px;
}

.btn:hover {
  background-color: var(--color-warm-oak);
}

/* Footer */
footer {
  background-color: var(--color-dark-walnut);
  color: var(--color-soft-linen);
  padding: var(--spacing-lg) var(--spacing-md);
  margin-top: var(--spacing-xl);
}

.footer-container {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.footer-section h3 {
  color: var(--color-warm-oak);
  margin-bottom: var(--spacing-sm);
  font-size: 1.1rem;
}

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

.footer-section a {
  color: var(--color-soft-linen);
  opacity: 0.9;
}

.footer-section a:hover {
  opacity: 1;
  color: var(--color-warm-oak);
}

.footer-bottom {
  text-align: center;
  margin-top: var(--spacing-lg);
  padding-top: var(--spacing-md);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  opacity: 0.8;
}

/* Back to top button */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-md);
  right: var(--spacing-md);
  background-color: var(--color-dark-walnut);
  color: var(--color-soft-linen);
  width: 50px;
  height: 50px;
  border-radius: 50%;
  display: none;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background-color var(--transition-smooth);
  z-index: 999;
  border: none;
  font-size: 1.5rem;
}

.back-to-top:hover {
  background-color: var(--color-warm-oak);
}

.back-to-top.visible {
  display: flex;
}

/* Responsive design */
@media (max-width: 768px) {
  .burger-menu {
    display: block;
  }
  
  nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-dark-walnut);
    padding: var(--spacing-md);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
  }
  
  nav.active {
    display: block;
  }
  
  nav ul {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
  
  .asymmetric-layout,
  .asymmetric-layout.reverse {
    grid-template-columns: 1fr;
  }
  
  .hero {
    min-height: 50vh;
    padding: var(--spacing-lg) var(--spacing-md);
  }
  
  .section {
    margin: var(--spacing-lg) 0;
    padding: var(--spacing-md) 0;
  }
  
  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  main {
    padding: var(--spacing-sm);
  }
  
  .hero {
    min-height: 40vh;
  }
  
  .contact-form {
    padding: var(--spacing-md);
  }
}

/* 320px and below - extra small devices */
@media (max-width: 320px) {
  header {
    padding: var(--spacing-xs) var(--spacing-sm);
  }
  
  .logo {
    font-size: 1.2rem;
  }
  
  .burger-menu {
    font-size: 1.2rem;
    padding: 0.25rem;
  }
  
  nav {
    padding: var(--spacing-sm);
  }
  
  nav ul {
    gap: var(--spacing-xs);
  }
  
  nav a {
    font-size: 0.85rem;
  }
  
  main {
    padding: var(--spacing-xs);
  }
  
  .hero {
    min-height: 35vh;
    padding: var(--spacing-md) var(--spacing-sm);
  }
  
  .hero h1 {
    font-size: 1.5rem;
  }
  
  .hero p {
    font-size: 0.9rem;
  }
  
  .section {
    margin: var(--spacing-md) 0;
    padding: var(--spacing-sm) 0;
  }
  
  .section-title {
    font-size: 1.5rem;
    padding-left: var(--spacing-sm);
    border-left-width: 3px;
  }
  
  h1 {
    font-size: 1.75rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  h3 {
    font-size: 1.25rem;
  }
  
  p {
    font-size: 0.9rem;
    line-height: 1.6;
  }
  
  .card {
    padding: var(--spacing-sm);
  }
  
  .card img {
    height: 200px;
  }
  
  .technical-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
  }
  
  .technical-item {
    padding: var(--spacing-sm);
  }
  
  .diagram-container {
    padding: var(--spacing-sm);
  }
  
  .diagram-item {
    padding: var(--spacing-xs);
    margin: var(--spacing-sm) 0;
  }
  
  .gallery-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
  }
  
  .contact-form {
    padding: var(--spacing-sm);
  }
  
  .form-group {
    margin-bottom: var(--spacing-sm);
  }
  
  .form-group input,
  .form-group textarea,
  .form-group select {
    padding: var(--spacing-xs);
    font-size: 0.9rem;
  }
  
  .form-group textarea {
    min-height: 120px;
  }
  
  .btn {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.9rem;
  }
  
  footer {
    padding: var(--spacing-md) var(--spacing-sm);
  }
  
  .footer-container {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }
  
  .footer-section h3 {
    font-size: 1rem;
  }
  
  .footer-section p,
  .footer-section a {
    font-size: 0.85rem;
  }
  
  .back-to-top {
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
    bottom: var(--spacing-sm);
    right: var(--spacing-sm);
  }
  
  .grid-2,
  .grid-3 {
    gap: var(--spacing-sm);
  }
}

/* Print styles */
@media print {
  header,
  footer,
  .back-to-top {
    display: none;
  }
  
  body {
    background: white;
    color: black;
  }
}