/* ===== CSS Variables ===== */
:root {
  --color-primary: #2d5a47;
  --color-primary-light: #3d7a5f;
  --color-secondary: #8b7355;
  --color-accent: #c4a77d;
  --color-background: #faf9f7;
  --color-surface: #ffffff;
  --color-text: #2c2c2c;
  --color-text-muted: #666666;
  --color-border: #e5e5e5;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif: 'Playfair Display', Georgia, serif;

  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;

  --max-width: 1200px;
  --header-height: 80px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-background);
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--color-primary-light);
}

/* ===== Typography ===== */
h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 500;
  line-height: 1.3;
  color: var(--color-text);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
  margin-bottom: var(--spacing-sm);
}

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

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

/* ===== Header ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

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

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

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text);
  padding: var(--spacing-xs) 0;
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width 0.2s ease;
}

.nav-link:hover {
  color: var(--color-primary);
}

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

/* Mobile Nav Toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
}

.hamburger {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  position: relative;
}

.hamburger::before,
.hamburger::after {
  content: '';
  position: absolute;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  left: 0;
}

.hamburger::before { top: -7px; }
.hamburger::after { top: 7px; }

/* ===== Main Content ===== */
main {
  margin-top: var(--header-height);
}

/* ===== Hero Section ===== */
.hero {
  min-height: calc(100vh - var(--header-height));
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--color-background) 0%, #f0ebe4 100%);
  padding: var(--spacing-xl) 0;
}

.hero-content {
  max-width: 700px;
}

.hero h1 {
  font-size: 3.5rem;
  margin-bottom: var(--spacing-md);
  color: var(--color-primary);
}

.hero .tagline {
  font-size: 1.35rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-lg);
  line-height: 1.7;
}

.btn {
  display: inline-block;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: 4px;
  font-weight: 500;
  font-size: 1rem;
  transition: all 0.2s ease;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--color-primary);
  color: white;
}

.btn-primary:hover {
  background: var(--color-primary-light);
  color: white;
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
  margin-left: var(--spacing-sm);
}

.btn-secondary:hover {
  background: var(--color-primary);
  color: white;
}

/* ===== About Section ===== */
#about {
  background: var(--color-surface);
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-lg);
}

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

.section-header p {
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto;
}

.about-content {
  max-width: 800px;
  margin: 0 auto;
  font-size: 1.1rem;
  line-height: 1.8;
}

/* ===== Projects Section ===== */
#projects {
  background: var(--color-background);
}

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

.project-card {
  background: var(--color-surface);
  border-radius: 8px;
  padding: var(--spacing-md);
  border: 1px solid var(--color-border);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

.project-card h3 {
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary);
}

.project-card p {
  color: var(--color-text-muted);
}

.project-card .btn {
  margin-left: 0;
  margin-top: var(--spacing-sm);
}

/* ===== Contact Section ===== */
#contact {
  background: var(--color-surface);
}

.contact-content {
  text-align: center;
  max-width: 600px;
  margin: 0 auto;
}

/* ===== Contact Form ===== */
.contact-form {
  margin-top: var(--spacing-md);
  text-align: left;
}

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

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

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-family: var(--font-sans);
  font-size: 1rem;
  background: var(--color-background);
  color: var(--color-text);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(45, 90, 71, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.contact-form .btn {
  margin-top: var(--spacing-sm);
  width: 100%;
}

/* ===== Footer ===== */
.site-footer {
  background: var(--color-primary);
  color: white;
  padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: var(--spacing-md);
}

.footer-brand .logo-text {
  color: white;
}

.footer-tagline {
  color: rgba(255, 255, 255, 0.8);
  font-size: 0.9rem;
  margin-top: var(--spacing-xs);
  max-width: 300px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.8);
  font-size: 0.9rem;
}

.footer-links a:hover {
  color: white;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  padding-top: var(--spacing-md);
  text-align: center;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
}

/* ===== Single Page ===== */
.page-hero {
  background: linear-gradient(135deg, var(--color-background) 0%, #f0ebe4 100%);
  padding: var(--spacing-xl) 0;
  text-align: center;
}

.page-hero h1 {
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
}

.page-subtitle {
  font-size: 1.25rem;
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto;
}

.page-content {
  background: var(--color-surface);
  padding: var(--spacing-lg) 0;
}

.page-content .container {
  max-width: 800px;
}

.page-content h2 {
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary);
}

.page-content h2:first-child {
  margin-top: 0;
}

.page-content p {
  font-size: 1.1rem;
  line-height: 1.8;
}

.page-content ul, .page-content ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-md);
}

.page-content li {
  margin-bottom: var(--spacing-xs);
  line-height: 1.7;
}

/* Feature Cards for subpages */
.page-features {
  background: var(--color-background);
  padding: var(--spacing-xl) 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-md);
}

.feature-card {
  background: var(--color-surface);
  border-radius: 8px;
  padding: var(--spacing-md);
  border: 1px solid var(--color-border);
  text-align: center;
}

.feature-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-sm);
}

.feature-card h3 {
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
}

.feature-card p {
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-sm);
}

.feature-card .btn {
  margin-top: var(--spacing-sm);
}

/* Back link */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: var(--spacing-md);
  font-size: 0.95rem;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  :root {
    --header-height: 70px;
  }

  h1 { font-size: 2.25rem; }
  h2 { font-size: 1.75rem; }

  .nav-toggle {
    display: block;
  }

  .main-nav {
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-md);
    display: none;
  }

  .main-nav.active {
    display: block;
  }

  .main-nav .nav-list {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .hero h1 {
    font-size: 2.5rem;
  }

  .hero .tagline {
    font-size: 1.15rem;
  }

  .btn-secondary {
    margin-left: 0;
    margin-top: var(--spacing-sm);
    display: block;
    text-align: center;
  }

  .footer-content {
    flex-direction: column;
    gap: var(--spacing-md);
  }
}