:root {
  --color-primary: #3b82f6;
  --color-primary-dark: #2563eb;
  --color-primary-light: #60a5fa;
  --color-secondary: #8b5cf6;
  --color-accent: #06b6d4;
  --color-text: #1f2937;
  --color-text-light: #6b7280;
  --color-text-muted: #9ca3af;
  --color-bg: #ffffff;
  --color-bg-alt: #f9fafb;
  --color-bg-dark: #111827;
  --color-border: #e5e7eb;
  --color-success: #10b981;
  --color-error: #ef4444;
  --color-warning: #f59e0b;
  
  --font-primary: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
  
  --max-width: 1200px;
  --max-width-narrow: 800px;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  --border-radius: 0.5rem;
  --border-radius-lg: 1rem;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;
}

/* Reset and Base Styles */
*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
}

input,
button,
textarea,
select {
  font: inherit;
}

p,
h1,
h2,
h3,
h4,
h5,
h6 {
  overflow-wrap: break-word;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-text);
}

h1 {
  font-size: clamp(2rem, 4vw, 3.5rem);
}

h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
}

h3 {
  font-size: clamp(1.25rem, 2.5vw, 1.75rem);
}

p {
  font-size: clamp(1rem, 1.5vw, 1.125rem);
  color: var(--color-text-light);
}

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

.container--narrow {
  max-width: var(--max-width-narrow);
}

/* Header and Navigation */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  transition: var(--transition-normal);
}

.nav__container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.nav__brand {
  display: flex;
  align-items: center;
}

.nav__logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-primary);
  text-decoration: none;
}

.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 2.5rem;
  height: 2.5rem;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  position: relative;
}

.nav__hamburger,
.nav__hamburger::before,
.nav__hamburger::after {
  width: 1.5rem;
  height: 2px;
  background-color: var(--color-text);
  transition: var(--transition-normal);
}

.nav__hamburger {
  position: relative;
}

.nav__hamburger::before,
.nav__hamburger::after {
  content: '';
  position: absolute;
  left: 0;
}

.nav__hamburger::before {
  top: -0.5rem;
}

.nav__hamburger::after {
  top: 0.5rem;
}

.nav__toggle[aria-expanded="true"] .nav__hamburger {
  background-color: transparent;
}

.nav__toggle[aria-expanded="true"] .nav__hamburger::before {
  transform: rotate(45deg);
  top: 0;
}

.nav__toggle[aria-expanded="true"] .nav__hamburger::after {
  transform: rotate(-45deg);
  top: 0;
}

.nav__list {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
  margin: 0;
  padding: 0;
}

.nav__link {
  text-decoration: none;
  color: var(--color-text);
  font-weight: 500;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius);
  transition: var(--transition-fast);
  position: relative;
}

.nav__link:hover,
.nav__link:focus {
  color: var(--color-primary);
  background-color: rgba(59, 130, 246, 0.1);
  outline: none;
}

.nav__link:focus {
  box-shadow: 0 0 0 2px var(--color-primary);
}

/* Hero Section */
.hero {
  padding: calc(4rem + var(--spacing-3xl)) var(--spacing-md) var(--spacing-3xl);
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.1);
  z-index: 1;
}

.hero__container {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-3xl);
  align-items: center;
  position: relative;
  z-index: 2;
}

.hero__content {
  max-width: 600px;
}

.hero__title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--spacing-lg);
  color: white;
}

.hero__subtitle {
  font-size: clamp(1.125rem, 2vw, 1.25rem);
  line-height: 1.6;
  margin-bottom: var(--spacing-xl);
  color: rgba(255, 255, 255, 0.9);
}

.hero__cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md) var(--spacing-xl);
  background-color: white;
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 1.125rem;
  border-radius: var(--border-radius-lg);
  border: none;
  cursor: pointer;
  transition: var(--transition-normal);
  box-shadow: var(--shadow-lg);
  min-width: 160px;
}

.hero__cta:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
  background-color: var(--color-bg-alt);
}

.hero__cta:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.5), var(--shadow-xl);
  background-color: var(--color-bg-alt);
}

.hero__cta:active {
  transform: translateY(0);
}

.hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero__graphic {
  position: relative;
  width: 300px;
  height: 300px;
}

.hero__circle {
  position: absolute;
  border-radius: 50%;
  animation: float 6s ease-in-out infinite;
}

.hero__circle--primary {
  width: 200px;
  height: 200px;
  background: rgba(255, 255, 255, 0.2);
  top: 50px;
  left: 50px;
  animation-delay: 0s;
}

.hero__circle--secondary {
  width: 120px;
  height: 120px;
  background: rgba(255, 255, 255, 0.15);
  top: 20px;
  right: 20px;
  animation-delay: 2s;
}

.hero__circle--accent {
  width: 80px;
  height: 80px;
  background: rgba(255, 255, 255, 0.1);
  bottom: 30px;
  left: 30px;
  animation-delay: 4s;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-20px);
  }
}

/* Features Section */
.features {
  padding: var(--spacing-3xl) var(--spacing-md);
  background-color: var(--color-bg-alt);
}

.features__container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.features__header {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
}

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

.features__subtitle {
  font-size: 1.125rem;
  color: var(--color-text-light);
  max-width: 600px;
  margin: 0 auto;
}

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

.feature-card {
  background-color: white;
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  transition: var(--transition-normal);
  text-align: center;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.feature-card__icon {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 4rem;
  height: 4rem;
  background-color: rgba(59, 130, 246, 0.1);
  border-radius: 50%;
  margin: 0 auto var(--spacing-lg);
  color: var(--color-primary);
}

.feature-card__title {
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

.feature-card__description {
  color: var(--color-text-light);
  line-height: 1.6;
}

/* About Section */
.about {
  padding: var(--spacing-3xl) var(--spacing-md);
}

.about__container {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: var(--spacing-3xl);
  align-items: center;
}

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

.about__text {
  margin-bottom: var(--spacing-lg);
  font-size: 1.125rem;
  line-height: 1.7;
}

.about__text:last-child {
  margin-bottom: 0;
}

.about__stats {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.stat {
  text-align: center;
  padding: var(--spacing-lg);
  background-color: var(--color-bg-alt);
  border-radius: var(--border-radius-lg);
}

.stat__number {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: var(--spacing-sm);
}

.stat__label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Contact Section */
.contact {
  padding: var(--spacing-3xl) var(--spacing-md);
  background-color: var(--color-bg-alt);
}

.contact__container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.contact__header {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
}

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

.contact__subtitle {
  font-size: 1.125rem;
  color: var(--color-text-light);
  max-width: 600px;
  margin: 0 auto;
}

.contact__content {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: var(--spacing-3xl);
}

.contact__form {
  background-color: white;
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
}

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

.form-label {
  display: block;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
}

.form-input,
.form-textarea {
  width: 100%;
  padding: var(--spacing-md);
  border: 2px solid var(--color-border);
  border-radius: var(--border-radius);
  font-size: 1rem;
  transition: var(--transition-fast);
  background-color: white;
}

.form-input:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

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

.form-error {
  display: block;
  color: var(--color-error);
  font-size: 0.875rem;
  margin-top: var(--spacing-xs);
  min-height: 1.25rem;
}

.form-submit {
  width: 100%;
  padding: var(--spacing-md) var(--spacing-xl);
  background-color: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--border-radius);
  font-size: 1.125rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-normal);
}

.form-submit:hover {
  background-color: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.form-submit:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.3);
}

.form-submit:active {
  transform: translateY(0);
}

.contact__info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.contact-item {
  padding: var(--spacing-lg);
  background-color: white;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
}

.contact-item__title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
}

.contact-item__text {
  color: var(--color-text-light);
  font-size: 1rem;
}

/* Footer */
.footer {
  background-color: var(--color-bg-dark);
  color: white;
  padding: var(--spacing-3xl) var(--spacing-md) var(--spacing-lg);
}

.footer__container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.footer__content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer__logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-primary-light);
  margin-bottom: var(--spacing-sm);
}

.footer__tagline {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.875rem;
}

.footer__nav {
  justify-self: end;
}

.footer__links {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
  margin: 0;
  padding: 0;
}

.footer__link {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  font-size: 0.875rem;
  transition: var(--transition-fast);
}

.footer__link:hover,
.footer__link:focus {
  color: var(--color-primary-light);
  outline: none;
}

.footer__bottom {
  padding-top: var(--spacing-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
}

.footer__copyright {
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.875rem;
}

/* Responsive Design */
@media (max-width: 768px) {
  .nav__toggle {
    display: flex;
  }
  
  .nav__list {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: white;
    border-top: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    flex-direction: column;
    padding: var(--spacing-md);
    gap: 0;
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-normal);
  }
  
  .nav__list.nav__list--open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .nav__item {
    width: 100%;
  }
  
  .nav__link {
    display: block;
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
    border-radius: 0;
  }
  
  .nav__link:last-child {
    border-bottom: none;
  }
  
  .hero__container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--spacing-xl);
  }
  
  .hero__visual {
    order: -1;
  }
  
  .hero__graphic {
    width: 250px;
    height: 250px;
  }
  
  .about__container {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }
  
  .about__stats {
    flex-direction: row;
    justify-content: space-around;
  }
  
  .contact__content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }
  
  .footer__content {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--spacing-lg);
  }
  
  .footer__nav {
    justify-self: center;
  }
  
  .footer__links {
    justify-content: center;
    flex-wrap: wrap;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: calc(4rem + var(--spacing-xl)) var(--spacing-md) var(--spacing-xl);
  }
  
  .features__grid {
    grid-template-columns: 1fr;
  }
  
  .about__stats {
    flex-direction: column;
  }
  
  .footer__links {
    flex-direction: column;
    gap: var(--spacing-md);
  }
}

/* Accessibility Enhancements */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  html {
    scroll-behavior: auto;
  }
}

/* Focus visible for better keyboard navigation */
.nav__link:focus-visible,
.hero__cta:focus-visible,
.form-input:focus-visible,
.form-textarea:focus-visible,
.form-submit:focus-visible,
.footer__link:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --color-text: #000000;
    --color-text-light: #333333;
    --color-border: #000000;
  }
  
  .hero {
    background: #000000;
  }
  
  .feature-card,
  .contact__form,
  .contact-item {
    border: 2px solid var(--color-border);
  }
}