:root {
  --color-white: #FFFFFF;
  --color-graphite: #1F2933;
  --color-gray: #6B7280;
  --color-blue: #2563EB;
  --color-mint: #22C55E;
  --color-bg: #F9FAFB;
  
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;
  
  --max-width: 1200px;
  --grid-gap: 2rem;
}

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

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

body {
  font-family: var(--font-sans);
  color: var(--color-graphite);
  background-color: var(--color-white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.2;
  color: var(--color-graphite);
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  margin-bottom: var(--spacing-md);
}

h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: var(--spacing-md);
}

h3 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: var(--spacing-sm);
}

p {
  margin-bottom: var(--spacing-sm);
  font-size: 1.125rem;
}

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

a:hover {
  color: var(--color-graphite);
}

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Header */
header {
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 100;
}

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-md);
  max-width: var(--max-width);
  margin: 0 auto;
}

.logo {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-graphite);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: var(--spacing-md);
  align-items: center;
}

.nav-links a {
  color: var(--color-graphite);
  font-size: 0.9375rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.nav-links a:hover {
  color: var(--color-blue);
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--color-graphite);
}

.menu-close {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--color-graphite);
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-md);
}

/* Hero Sections */
.hero {
  padding: var(--spacing-xl) var(--spacing-md);
  min-height: 60vh;
  display: flex;
  align-items: center;
}

.hero-content {
  max-width: var(--max-width);
  margin: 0 auto;
  width: 100%;
}

.hero-left {
  text-align: left;
  max-width: 700px;
}

.hero-center {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.hero-right {
  text-align: right;
  max-width: 700px;
  margin-left: auto;
}

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

.hero p {
  font-size: 1.25rem;
  color: var(--color-gray);
  margin-bottom: var(--spacing-md);
}

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

.section-alt {
  background-color: var(--color-bg);
}

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

/* Grid Systems */
.grid {
  display: grid;
  gap: var(--grid-gap);
}

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

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

/* Horizontal Scroll */
.horizontal-scroll {
  display: flex;
  gap: var(--spacing-md);
  overflow-x: auto;
  padding: var(--spacing-md) 0;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.horizontal-scroll-item {
  flex: 0 0 400px;
  scroll-snap-align: start;
  background: var(--color-white);
  padding: var(--spacing-md);
  border: 1px solid var(--color-bg);
}

/* Timeline */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: var(--spacing-md);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-blue);
}

.timeline-item {
  position: relative;
  padding-bottom: var(--spacing-lg);
  padding-left: var(--spacing-lg);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -6px;
  top: 0;
  width: 12px;
  height: 12px;
  background: var(--color-blue);
  border-radius: 50%;
}

.timeline-item h3 {
  margin-bottom: var(--spacing-xs);
}

/* Forms */
form {
  max-width: 600px;
  margin: 0 auto;
}

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

label {
  display: block;
  margin-bottom: var(--spacing-xs);
  font-weight: 500;
  color: var(--color-graphite);
}

input[type="text"],
input[type="email"],
select,
textarea {
  width: 100%;
  padding: var(--spacing-sm);
  border: 1px solid var(--color-gray);
  border-radius: 4px;
  font-family: var(--font-sans);
  font-size: 1rem;
  transition: border-color 0.2s ease;
}

input[type="text"]:focus,
input[type="email"]:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--color-blue);
}

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

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

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

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

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

/* Footer */
footer {
  background-color: var(--color-graphite);
  color: var(--color-white);
  padding: var(--spacing-lg) var(--spacing-md);
  margin-top: var(--spacing-xl);
}

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

.footer-section h3 {
  color: var(--color-white);
  margin-bottom: var(--spacing-sm);
  font-size: 1.125rem;
}

.footer-section a {
  color: var(--color-gray);
  display: block;
  margin-bottom: var(--spacing-xs);
}

.footer-section a:hover {
  color: var(--color-white);
}

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

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--color-white);
    flex-direction: column;
    padding: var(--spacing-md);
    padding-top: 3rem;
    border-bottom: 1px solid var(--color-bg);
    display: none;
    z-index: 1000;
  }

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

  .menu-toggle {
    display: block;
  }

  .menu-close {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--color-graphite);
  }

  .menu-close.active {
    display: block;
    position: fixed;
    top: var(--spacing-xl);
    right: var(--spacing-md);
    z-index: 1001;
  }
  
  nav.active .menu-close {
    display: block;
    position: fixed;
    top: var(--spacing-xl);
    right: var(--spacing-md);
    z-index: 1001;
  }

  .hero {
    min-height: 50vh;
    padding: var(--spacing-lg) var(--spacing-md);
  }

  .section {
    padding: var(--spacing-lg) var(--spacing-md);
  }

  .horizontal-scroll-item {
    flex: 0 0 300px;
  }
}

@media (max-width: 320px) {
  html {
    font-size: 14px;
  }

  nav {
    padding: var(--spacing-xs) var(--spacing-sm);
  }

  .logo {
    font-size: 1rem;
  }

  .nav-links {
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
  }

  .nav-links a {
    font-size: 0.8125rem;
  }

  .hero {
    padding: var(--spacing-md) var(--spacing-sm);
    min-height: 40vh;
  }

  .hero h1 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-sm);
  }

  .hero p {
    font-size: 1rem;
  }

  .section {
    padding: var(--spacing-md) var(--spacing-sm);
  }

  h2 {
    font-size: 1.5rem;
  }

  h3 {
    font-size: 1.25rem;
  }

  p {
    font-size: 1rem;
  }

  .container {
    padding: 0 var(--spacing-sm);
  }

  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }

  .horizontal-scroll-item {
    flex: 0 0 280px;
    padding: var(--spacing-sm);
  }

  .timeline {
    padding-left: var(--spacing-sm);
  }

  .timeline-item {
    padding-left: var(--spacing-md);
  }

  form {
    max-width: 100%;
  }

  .btn {
    width: 100%;
    padding: var(--spacing-sm);
    font-size: 0.9375rem;
  }

  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }

  .footer-section {
    margin-bottom: var(--spacing-md);
  }

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

/* Utility Classes */
.text-center {
  text-align: center;
}

.text-muted {
  color: var(--color-gray);
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.mb-lg {
  margin-bottom: var(--spacing-lg);
}