/* ========================================
   VERTEX4D - Arquitetura CSS
   ======================================== */

/* ========================================
   1. Propriedades do CSS (Variáveis)
   ======================================== */

:root {
  /* Colors */
  --primary-blue: #035184;
  --primary-blue-dark: #013d6b;
  --primary-blue-light: #0284c7;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-light: #94a3b8;
  --background-white: #ffffff;
  --background-light: #f8fafc;
  --background-gray: #e2e8f0;
  --background-dark: #0f172a;
  --background-dark-light: #1e293b;

  /* Typography */
  --font-primary: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-brand: "Teorema", sans-serif;
  --font-size-xs: 0.875rem;
  --font-size-sm: 1rem;
  --font-size-base: 1.25rem;
  --font-size-lg: 1.6rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 2.5rem;
  --font-size-4xl: 3rem;
  --font-size-hero: 3.70rem;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 0.8rem;
  --space-md: 1.5rem;
  --space-lg: 1.4rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;

  /* Layout */
  --container-max-width: 1200px;
  --navbar-height: 76px;
  --border-radius: 8px;
  --border-radius-lg: 12px;
  --border-radius-xl: 20px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  --shadow-hero: 0 32px 80px 0 rgba(1, 84, 140, 0.22);

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.6s ease;
}

/* ========================================
     2. Declaração Font-Face
     ======================================== */
@font-face {
  font-family: "Teorema";
  src: local("Teorema Light"), local("Teorema-Light"), url("../fonts/TeoremaLight.woff2") format("woff2"),
    url("../fonts/TeoremaLight.woff") format("woff"), url("../fonts/TeoremaLight.ttf") format("truetype");
  font-weight: 300;
  font-style: normal;
  font-display: swap;
}

/* ========================================
     3. RESET e BASE STYLES
     ======================================== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--background-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* ========================================
     4. LAYOUT
     ======================================== */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  width: 100%;
}

/* ========================================
     5. NAVIGATION
     ======================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
  z-index: 1000;
  transition: all var(--transition-base);
}

.nav-container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: var(--navbar-height);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  cursor: pointer;
}

.nav-brand a {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
}

.logo {
  height: 32px;
  width: auto;
  transition: transform var(--transition-base);
}

.logo:hover {
  transform: scale(1.05);
}

.brand-text {
  font-family: var(--font-brand);
  font-size: var(--font-size-xl);
  font-weight: 300;
  color: var(--primary-blue);
  text-decoration: none;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
  list-style: none;
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-weight: 500;
  transition: all var(--transition-base);
  position: relative;
  padding: var(--space-xs) 0;
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary-blue);
  transform: translateY(-1px);
}

.nav-link::after {
  content: "";
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -2px;
  left: 50%;
  background-color: var(--primary-blue);
  transition: all var(--transition-base);
  transform: translateX(-50%);
}

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

.platform-btn {
  text-decoration: none;
  background: var(--primary-blue);
  color: var(--background-white) !important;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--border-radius);
  font-weight: 620;
  transition: all var(--transition-base);
  border: none;
  outline: none;
}

.platform-btn::after {
  display: none;
}

.platform-btn:hover,
.platform-btn:focus {
  background: var(--primary-blue-dark);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(1, 84, 140, 0.3);
}

/* ========================================
     6. MOBILE NAVIGATION
     ======================================== */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 4px;
  z-index: 1001;
  background: none;
  border: none;
  padding: var(--space-xs);
}

.mobile-menu-toggle span {
  width: 25px;
  height: 3px;
  background: var(--text-primary);
  transition: var(--transition-base);
  border-radius: 2px;
}

.mobile-menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -6px);
}

.mobile-sidebar {
  position: fixed;
  top: 0;
  right: -100%;
  width: min(320px, 85vw);
  height: 100vh;
  background: var(--background-white);
  box-shadow: -4px 0 20px rgba(0, 0, 0, 0.15);
  z-index: 1000;
  transition: right var(--transition-base);
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--background-gray);
}

.mobile-sidebar.active {
  right: 0;
}

.mobile-sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-lg);
  border-bottom: 1px solid var(--background-gray);
}

.mobile-sidebar-brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.mobile-sidebar-brand .logo {
  height: 28px;
  width: auto;
}

.mobile-sidebar-brand .brand-text {
  font-family: var(--font-brand);
  font-size: var(--font-size-lg);
  font-weight: 300;
  color: var(--primary-blue);
}

.mobile-sidebar-close {
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-xs);
  border-radius: var(--border-radius);
  transition: background-color var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.mobile-sidebar-close:hover {
  background-color: var(--background-light);
}

.mobile-sidebar-close svg {
  width: 20px;
  height: 20px;
  color: var(--text-secondary);
}

.mobile-sidebar-nav {
  flex: 1;
  padding: var(--space-lg) 0;
}

.mobile-sidebar-nav a {
  display: flex;
  align-items: center;
  padding: var(--space-md) var(--space-lg);
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 500;
  transition: all var(--transition-fast);
  border-left: 3px solid transparent;
}

.mobile-sidebar-nav a:hover,
.mobile-sidebar-nav a.active {
  background-color: var(--background-light);
  color: var(--primary-blue);
  border-left-color: var(--primary-blue);
}

.mobile-sidebar-nav .platform-btn {
  margin: var(--space-lg);
  background: var(--primary-blue);
  color: var(--background-white) !important;
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--border-radius);
  text-align: center;
  font-weight: 600;
  border-left: none !important;
}

.mobile-sidebar-nav .platform-btn:hover {
  background: var(--primary-blue-dark);
  border-left: none !important;
}

.mobile-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.mobile-overlay.active {
  opacity: 1;
  visibility: visible;
}

/* ========================================
     7. HERO SECTION (Principal)
     ======================================== */
.hero {
  min-height: 100vh;
  padding: 0;
  display: flex;
  align-items: center;
  background: var(--background-light);
}

.hero-container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
  width: 100%;
}

.hero-content {
  animation: fadeInUp 0.8s ease;
}

.hero-title {
  font-size: var(--font-size-hero);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: var(--space-sm);
  color: var(--text-primary);
}

.highlight-word {
  background: linear-gradient(135deg, #425263 0%, #576a7e 25%, #808f9e 55%, #657483 75%, #2a3b4d 100%);
  color: transparent;
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
  font-weight: inherit;
}

.hero-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  margin-bottom: var(--space-2xl);
  line-height: 1.6;
  max-width: 750px;
}

.cta-button {
  display: inline-block;
  background: var(--primary-blue);
  color: var(--background-white);
  padding: var(--space-md) var(--space-xl);
  border-radius: var(--border-radius-lg);
  text-decoration: none;
  font-weight: 600;
  font-size: var(--font-size-base);
  transition: all var(--transition-base);
  border: none;
  cursor: pointer;
  outline: none;
}

.cta-button:hover,
.cta-button:focus {
  background: var(--primary-blue-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(1, 84, 140, 0.3);
}

.hero-video {
  position: relative;
  border-radius: var(--border-radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-hero), var(--shadow-lg);
  animation: fadeInRight 0.8s ease;
  background: var(--background-white);
  aspect-ratio: 4 / 3;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-video video {
  width: 100%;
  height: 100%;
  display: block;
  border-radius: var(--border-radius-xl);
  background: #000;
  object-fit: cover;
}

/* ========================================
     8. SECTIONS & CONTENT
     ======================================== */
.about {
  padding: var(--space-3xl) 0;
}

.about-box-large {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-blue-dark) 100%);
  color: var(--background-white);
  padding: var(--space-3xl) var(--space-2xl);
  border-radius: var(--border-radius-xl);
  box-shadow: 0 20px 40px rgba(1, 84, 140, 0.2);
}

.about-box-large h2 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--space-lg);
}

.about-box-large p {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-2xl);
  opacity: 0.9;
  line-height: 1.6;
}

.about-button-large {
  display: inline-block;
  background: var(--background-white);
  color: var(--primary-blue);
  padding: var(--space-lg) var(--space-2xl);
  border-radius: var(--border-radius-lg);
  text-decoration: none;
  font-weight: 700;
  font-size: var(--font-size-lg);
  transition: all var(--transition-base);
  border: none;
  cursor: pointer;
}

.about-button-large:hover {
  background: var(--background-light);
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(255, 255, 255, 0.3);
}

/* ========================================
     9. FEATURES SECTION
     ======================================== */
.features {
  padding: var(--space-3xl) 0;
}

.feature {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
  margin-bottom: var(--space-3xl);
  min-height: 400px;
}

.feature#interatividade {
  direction: ltr;
}

.feature#interatividade > * {
  direction: ltr;
}

.feature-content h2 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--space-lg);
  color: var(--text-primary);
}

.feature-content p {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  margin-bottom: var(--space-xl);
  line-height: 1.7;
}

.feature-btn {
  background: transparent;
  color: var(--primary-blue);
  border: 2px solid var(--primary-blue);
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--border-radius);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-base);
  outline: none;
  display: inline-block;
  text-decoration: none;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.feature-btn:hover,
.feature-btn:focus {
  background: var(--primary-blue);
  color: var(--background-white);
  transform: translateY(-2px);
}

.feature-media {
  border-radius: var(--border-radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-hero), var(--shadow-lg);
  background: var(--background-white);
  aspect-ratio: 4 / 3;
  display: flex;
  align-items: center;
  justify-content: center;
}

.feature-media video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: var(--border-radius-xl);
  background: #000;
}

/* ========================================
     10. HOW IT WORKS SECTION
     ======================================== */
.how-it-works {
  padding: var(--space-3xl) 0;
  background: var(--background-light);
}

.section-title {
  text-align: center;
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--space-3xl);
  color: var(--text-primary);
}

.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-3xl);
}

.step {
  text-align: center;
  animation: fadeInUp 0.6s ease;
}

.step:nth-child(2) {
  animation-delay: 0.2s;
}

.step:nth-child(3) {
  animation-delay: 0.4s;
}

.step-image {
  margin-bottom: var(--space-lg);
}

.step-image img {
  width: 100%;
  max-width: 300px;
  height: 300px;
  border-radius: var(--border-radius-xl);
  object-fit: cover;
  box-shadow: var(--shadow-lg);
  transition: transform var(--transition-base);
}

.step-image img:hover {
  transform: scale(1.05);
}

.step h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: var(--space-md);
  color: var(--text-primary);
}

.step p {
  color: var(--text-secondary);
  font-size: var(--font-size-base);
  line-height: 1.6;
}

/* ========================================
     11. ACCESS SECTION
     ======================================== */
.access-section {
  padding: var(--space-3xl) 0;
}

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

.access-box {
  background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-blue-dark) 100%);
  color: var(--background-white);
  padding: var(--space-3xl) var(--space-2xl);
  border-radius: var(--border-radius-xl);
  box-shadow: 0 20px 40px rgba(1, 84, 140, 0.2);
}

.access-title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--space-lg);
}

.access-description {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-2xl);
  opacity: 0.9;
  line-height: 1.6;
}

.access-button {
  display: inline-block;
  background: var(--background-white);
  color: var(--primary-blue);
  padding: var(--space-lg) var(--space-2xl);
  border-radius: var(--border-radius-lg);
  text-decoration: none;
  font-weight: 700;
  font-size: var(--font-size-lg);
  transition: all var(--transition-base);
  border: none;
  cursor: pointer;
}

.access-button:hover {
  background: var(--background-light);
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(255, 255, 255, 0.3);
}

/* ========================================
     12. FOOTER CTA SECTION
     ======================================== */
.footer-cta {
  padding: var(--space-3xl) 0;
  background: linear-gradient(90deg, var(--primary-blue) -50%, var(--primary-blue-dark) 0%);
  color: var(--background-white);
}

.cta-content {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
}

.cta-text h2 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  margin-bottom: var(--space-lg);
}

.cta-text p {
  font-size: var(--font-size-base);
  opacity: 0.9;
  line-height: 1.6;
}

.cta-contact {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: var(--space-lg);
}

.contact-info {
  text-align: right;
}

.contact-info h3 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-md);
}

.contact-item {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  margin-bottom: var(--space-sm);
  justify-content: flex-end;
}

.contact-icon {
  width: 20px;
  height: 20px;
  color: rgba(255, 255, 255, 0.8);
  flex-shrink: 0;
}

.contact-social {
  display: flex;
  gap: var(--space-xs);
  justify-content: flex-end;
  margin-top: var(--space-xs);
}

.social-link {
  color: rgba(255, 255, 255, 0.8);
  transition: all var(--transition-base);
  text-decoration: none;
  padding: var(--space-xs);
  border-radius: var(--border-radius);
}

.social-link:hover {
  color: var(--background-white);
  transform: translateY(-2px);
  background: rgba(255, 255, 255, 0.1);
}

.contact-btn {
  background: var(--background-white);
  color: var(--background-dark-light);
  padding: var(--space-md) var(--space-xl);
  border-radius: var(--border-radius);
  border: none;
  font-size: medium;
  color: var(--text-primary);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  display: inline-block;
  align-self: flex-end;
}

.contact-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(255, 255, 255, 0.2);
}

/* ========================================
     13. FOOTER
     ======================================== */
.footer {
  padding: var(--space-2xl) 0;
  background: var(--background-dark);
  color: var(--background-white);
}

.footer-content {
  text-align: center;
}

.footer-center {
  text-align: center;
  opacity: 0.8;
}

/* ========================================
     14. PAGE-SPECIFIC STYLES
     ======================================== */
.page-header {
  padding: calc(var(--navbar-height) + var(--space-3xl)) 0 var(--space-xl);
  background: linear-gradient(135deg, var(--background-light) 0%, var(--background-gray) 100%);
  text-align: center;
}

.breadcrumb {
  margin-bottom: var(--space-lg);
  font-size: var(--font-size-xs);
  color: var(--text-secondary);
}

.breadcrumb a {
  color: var(--primary-blue);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.page-header h1 {
  font-size: var(--font-size-4xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-md);
}

.page-subtitle {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  max-width: 800px;
  margin: 0 auto;
  line-height: 1.6;
}

.page-content {
  padding: var(--space-3xl) 0;
}

.content-centered {
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}

.content-block {
  margin-bottom: var(--space-xl);
}

.content-block h2 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-lg);
}

.content-block p {
  font-size: var(--font-size-base);
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-md);
}

.content-block p:last-child {
  margin-bottom: 0;
}

.video-container {
  position: relative;
  width: 100%;
  margin: var(--space-xl) 0;
  border-radius: var(--border-radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-hero), var(--shadow-lg);
  background: var(--background-white);
  aspect-ratio: 16 / 9;
  display: flex;
  align-items: center;
  justify-content: center;
}

.video-container video {
  width: 100%;
  height: 100%;
  display: block;
  background: #000;
  object-fit: cover;
}

.video-caption {
  font-size: var(--font-size-xs);
  color: var(--text-secondary);
  text-align: center;
  margin-top: var(--space-sm);
  font-style: italic;
}

.page-cta {
  padding: 0 0 var(--space-3xl);
}

.cta-box-large {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-blue-dark) 100%);
  color: var(--background-white);
  padding: var(--space-xl) var(--space-xl);
  border-radius: var(--border-radius-xl);
  box-shadow: 0 20px 40px rgba(1, 84, 140, 0.2);
}

.cta-box-large h2 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  margin-bottom: var(--space-lg);
}

.cta-box-large p {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-2xl);
  opacity: 0.9;
  line-height: 1.6;
}

.cta-button-large {
  display: inline-block;
  background: var(--background-white);
  color: var(--primary-blue);
  padding: var(--space-lg) var(--space-2xl);
  border-radius: var(--border-radius-lg);
  text-decoration: none;
  font-weight: 700;
  font-size: var(--font-size-lg);
  transition: all var(--transition-base);
  border: none;
  cursor: pointer;
}

.cta-button-large:hover {
  background: var(--background-light);
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(255, 255, 255, 0.3);
}

/* ========================================
     15. ANIMATIONS
     ======================================== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.page-animate {
  opacity: 0;
  transform: translateY(30px);
  transition: all var(--transition-slow);
}

.page-animate.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Ripple effect for buttons */
.ripple {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.6);
  transform: scale(0);
  animation: ripple-animation 0.6s linear;
  pointer-events: none;
}

@keyframes ripple-animation {
  to {
    transform: scale(4);
    opacity: 0;
  }
}

/* ========================================
     16. 404 ERROR PAGE STYLES
     ======================================== */
.error-404 {
  height: 100vh;
  padding: calc(var(--navbar-height) + var(--space-3xl)) 0 var(--space-3xl);
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--background-light) 0%, var(--background-gray) 100%);
}

.error-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
  max-width: 1000px;
  margin: 0 auto;
}

.error-visual {
  text-align: center;
  position: relative;
}

.error-number {
  font-size: 8rem;
  font-weight: 900;
  color: var(--primary-blue);
  line-height: 1;
  margin-bottom: var(--space-lg);
  opacity: 0.1;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1;
}

.error-icon {
  position: relative;
  z-index: 2;
  color: var(--primary-blue);
  margin-bottom: var(--space-lg);
}

.error-text {
  text-align: left;
}

.error-text h1 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-lg);
}

.error-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  line-height: 1.45;
  margin-bottom: var(--space-2xl);
}

.error-actions {
  display: flex;
  gap: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

.error-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--border-radius-lg);
  text-decoration: none;
  font-weight: 600;
  font-size: var(--font-size-base);
  transition: all var(--transition-base);
  border: none;
  cursor: pointer;
}

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

.error-btn.primary:hover {
  background: var(--primary-blue-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(1, 84, 140, 0.3);
}

.error-btn.secondary {
  background: transparent;
  color: var(--primary-blue);
  border: 2px solid var(--primary-blue);
}

.error-btn.secondary:hover {
  background: var(--primary-blue);
  color: var(--background-white);
  transform: translateY(-2px);
}

/* ========================================
     17. RESPONSIVE DESIGN - MOBILE FIRST
     ======================================== */

/* Tablet styles */
@media (max-width: 1024px) {
  :root {
    --font-size-hero: 3rem;
    --font-size-4xl: 2.5rem;
    --font-size-3xl: 2rem;
    --space-3xl: 4rem;
  }

  .hero-container {
    gap: var(--space-2xl);
  }

  .feature {
    gap: var(--space-2xl);
    min-height: 350px;
  }

  .cta-content {
    gap: var(--space-2xl);
  }

  .error-content {
    gap: var(--space-2xl);
  }
}

/* Mobile styles */
@media (max-width: 768px) {
  :root {
    --font-size-hero: 2.5rem;
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.75rem;
    --font-size-2xl: 1.5rem;
    --space-3xl: 3rem;
    --space-2xl: 2rem;
  }

  .container {
    padding: 0 var(--space-md);
  }

  .nav-container {
    padding: 0 var(--space-md);
  }

  /* Show mobile menu */
  .mobile-menu-toggle {
    display: flex;
  }

  .nav-menu {
    display: none;
  }

  /* Hero section mobile */
  .hero {
    min-height: 90vh;
    padding: var(--space-lg) 0;
  }

  .hero-container {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
    text-align: center;
    padding-top: var(--navbar-height);
  }

  .hero-title {
    font-size: var(--font-size-hero);
    line-height: 1.2;
  }

  .hero-description {
    font-size: var(--font-size-base);
    max-width: 100%;
  }

  .hero-video {
    width: 100%;
    max-width: 100%;
  }

  /* Features mobile */
  .feature {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
    text-align: center;
    min-height: auto;
  }

  .feature.reverse {
    direction: ltr;
  }

  .feature-content h2 {
    font-size: var(--font-size-2xl);
  }

  .feature-content p {
    font-size: var(--font-size-base);
  }

  /* Steps mobile */
  .steps {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }

  .step-image img {
    width: 100%;
    max-width: 280px;
    height: 280px;
  }

  /* Footer CTA mobile */
  .cta-content {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
    text-align: center;
  }

  .cta-contact {
    align-items: center;
  }

  .contact-info {
    text-align: center;
  }

  .contact-social {
    justify-content: center;
  }

  .contact-btn {
    align-self: center;
  }

  /* Page header mobile */
  .page-header {
    padding: calc(var(--navbar-height) + var(--space-2xl)) 0 var(--space-lg);
  }

  .page-header h1 {
    font-size: var(--font-size-3xl);
  }

  .page-subtitle {
    font-size: var(--font-size-base);
  }

  /* Content blocks mobile */
  .content-block h2 {
    font-size: var(--font-size-xl);
  }

  .about-box-large,
  .access-box,
  .cta-box-large {
    padding: var(--space-xl) var(--space-lg);
  }

  .about-box-large h2,
  .access-title,
  .cta-box-large h2 {
    font-size: var(--font-size-xl);
  }

  .about-box-large p,
  .access-description,
  .cta-box-large p {
    font-size: var(--font-size-base);
  }

  /* 404 Error mobile */
  .error-404 {
    padding: calc(var(--navbar-height) + var(--space-2xl)) 0 var(--space-2xl);
  }

  .error-content {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
    text-align: center;
  }

  .error-text {
    text-align: center;
  }

  .error-text h1 {
    font-size: var(--font-size-3xl);
  }

  .error-actions {
    flex-direction: column;
    align-items: center;
  }

  .error-btn {
    width: 100%;
    max-width: 300px;
    justify-content: center;
  }

  .suggestion-links {
    justify-content: center;
  }
}

/* Small mobile styles */
@media (max-width: 480px) {
  :root {
    --font-size-hero: 2rem;
    --font-size-3xl: 1.5rem;
    --font-size-2xl: 1.25rem;
    --space-2xl: 1.5rem;
    --space-xl: 2rem;
  }

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

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

  .hero-title {
    font-size: var(--font-size-hero);
  }

  .mobile-sidebar {
    width: min(280px, 90vw);
  }

  .step-image img {
    max-width: 250px;
    height: 250px;
  }

  .about-box-large,
  .access-box,
  .cta-box-large {
    padding: var(--space-xl) var(--space-md);
  }

  .error-number {
    font-size: 6rem;
  }

  .error-actions {
    gap: var(--space-md);
  }
}

/* ========================================
     YOUTUBE IFRAME STYLES
     ======================================== */
.hero-video iframe,
.feature-media iframe,
.video-container iframe {
  border: none;
  border-radius: var(--border-radius-xl);
  box-shadow: var(--shadow-hero), var(--shadow-lg);
}

.feature-media {
  position: relative;
  overflow: hidden;
}

.feature-media iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* ========================================
     18. UTILITY CLASSES
     ======================================== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

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

.hidden {
  display: none;
}

.visible {
  display: block;
}

/* Focus styles for accessibility */
button:focus-visible,
a:focus-visible {
  outline: 2px solid var(--primary-blue);
  outline-offset: 2px;
}