/* ============================================================
   KUROKO Introduction Website — Stylesheet
   ============================================================ */

/* ---------- CSS Custom Properties ---------- */
:root {
  /* Colors — KUROKO Design System */
  --color-navy-dark: #0e1125;
  --color-navy: #11142a;
  --color-navy-mid: #1a1f36;
  --color-teal: #5ce0c2;
  --color-teal-light: #7aedcf;
  --color-purple-blue: #7b8cde;
  --color-orange: #f5a623;
  --color-pink: #e080d0;
  --color-white: #ffffff;
  --color-text-light: rgba(255, 255, 255, 0.7);
  --color-text-lighter: rgba(255, 255, 255, 0.5);
  --color-text-dark: #1a1f36;
  --color-text-secondary: #555b6e;
  --color-bg-light: #f5f6f8;
  --color-card-bg: #ffffff;

  /* Glass morphism */
  --glass-bg: rgba(255, 255, 255, 0.04);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-border-hover: rgba(255, 255, 255, 0.15);
  --glass-blur: blur(12px);

  /* Shadows */
  --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.12);
  --shadow-glow-teal: 0 0 60px rgba(92, 224, 194, 0.1);

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-section: 96px;
  --space-section-mobile: 64px;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', 'Noto Sans JP', 'Segoe UI', sans-serif;
  --font-size-hero: 3rem;
  --font-size-section-title: 1.75rem;
  --font-size-card-title: 1.125rem;
  --font-size-body: 0.9375rem;
  --font-size-small: 0.8125rem;
  --line-height-body: 1.6;
  --line-height-heading: 1.3;

  /* Layout */
  --container-width: 960px;
  --container-wide: 1080px;
  --nav-height: 56px;

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-pill: 100px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
  -webkit-text-size-adjust: 100%;
}

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

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

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

button {
  background: none;
  border: none;
  cursor: pointer;
  font: inherit;
  color: inherit;
}

/* Focus visible */
:focus-visible {
  outline: 2px solid var(--color-teal);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0ms !important;
    animation-delay: 0ms !important;
    transition-duration: 0ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}

/* ---------- Utility: Container ---------- */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

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

/* ---------- Utility: Animations ---------- */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(8px); }
}

@keyframes cursorBlink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.anim-fade-in {
  opacity: 0;
  transition: opacity 0.6s ease-out;
}

.anim-fade-in.is-visible {
  opacity: 1;
}

.anim-fade-in-up {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
  will-change: opacity, transform;
}

.anim-fade-in-up.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.delay-1 { transition-delay: 0.15s; }
.delay-2 { transition-delay: 0.30s; }
.delay-3 { transition-delay: 0.45s; }
.delay-4 { transition-delay: 0.60s; }

/* ============================================================
   NAVIGATION
   ============================================================ */
.global-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  transition: background 0.3s ease, box-shadow 0.3s ease;
  background: transparent;
}

.global-nav.is-scrolled {
  background: rgba(17, 20, 42, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.05);
}

.nav-inner {
  max-width: var(--container-wide);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
}

.nav-logo-svg {
  width: 120px;
  height: auto;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav-link {
  font-size: var(--font-size-small);
  color: var(--color-text-lighter);
  transition: color 0.25s ease;
  position: relative;
  padding: 4px 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--color-teal);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-teal);
}

.nav-link.active::after {
  transform: scaleX(1);
}

.nav-link--cta {
  background: var(--color-teal);
  color: var(--color-navy) !important;
  padding: 6px 18px;
  border-radius: var(--radius-pill);
  font-weight: 600;
  transition: background 0.25s ease, transform 0.25s ease;
}

.nav-link--cta::after {
  display: none;
}

.nav-link--cta:hover {
  background: var(--color-teal-light);
  transform: translateY(-1px);
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 36px;
  height: 36px;
  position: relative;
  z-index: 1100;
}

.hamburger-line {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-white);
  border-radius: 1px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.hamburger-line--1 {
  margin-bottom: 4px;
}

.hamburger-line--3 {
  margin-top: 4px;
}

.hamburger.is-active .hamburger-line--1 {
  transform: translateY(6px) rotate(45deg);
}

.hamburger.is-active .hamburger-line--2 {
  opacity: 0;
}

.hamburger.is-active .hamburger-line--3 {
  transform: translateY(-6px) rotate(-45deg);
}

/* Mobile Overlay */
.mobile-overlay {
  position: fixed;
  inset: 0;
  background: rgba(17, 20, 42, 0.97);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 1050;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.mobile-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}

.mobile-nav-links {
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.mobile-nav-link {
  font-size: 1.25rem;
  color: var(--color-white);
  font-weight: 600;
  transition: color 0.25s ease;
}

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

/* ============================================================
   SECTION: HERO
   ============================================================ */
.section-hero {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: linear-gradient(160deg, #1a1f36 0%, #11142a 50%, #0e1125 100%);
  overflow: hidden;
  padding: var(--space-2xl);
}

.hero-bg-decoration {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero-gradient-circle {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
}

.hero-gradient-circle--tr {
  top: -20%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(92, 224, 194, 0.06) 0%, transparent 70%);
}

.hero-gradient-circle--bl {
  bottom: -20%;
  left: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(92, 224, 194, 0.03) 0%, transparent 70%);
}

.hero-noise {
  position: absolute;
  inset: 0;
  opacity: 0.03;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  background-size: 200px 200px;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 720px;
}

.hero-logo {
  margin-bottom: var(--space-lg);
}

.hero-logo svg {
  width: 240px;
  max-width: 100%;
  margin: 0 auto;
}

.hero-subtitle {
  font-size: var(--font-size-small);
  letter-spacing: 2px;
  color: var(--color-text-lighter);
  margin-bottom: var(--space-2xl);
  opacity: 0;
  animation: fadeIn 0.8s ease-out 0.3s forwards;
}

.hero-heading {
  font-size: var(--font-size-hero);
  font-weight: 700;
  color: var(--color-white);
  line-height: var(--line-height-heading);
  margin-bottom: var(--space-lg);
  min-height: 1.3em;
}

.hero-heading-inner .char {
  display: inline-block;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.hero-heading-inner .char.is-visible {
  opacity: 1;
}

.hero-cursor {
  display: inline-block;
  font-weight: 300;
  color: var(--color-teal);
  animation: cursorBlink 0.8s infinite;
  margin-left: 2px;
}

.hero-cursor.is-hidden {
  display: none;
}

.hero-sub-catch {
  font-size: 1.125rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-xl);
  opacity: 0;
  transition: opacity 0.6s ease-out;
}

.hero-sub-catch.is-visible {
  opacity: 1;
}

.hero-cta {
  opacity: 0;
  transition: opacity 0.6s ease-out;
}

.hero-cta.is-visible {
  opacity: 1;
}

/* Primary Button */
.btn-primary {
  display: inline-block;
  background: var(--color-teal);
  color: var(--color-navy);
  padding: 14px 40px;
  border-radius: var(--radius-pill);
  font-size: 1rem;
  font-weight: 600;
  transition: background 0.25s ease, transform 0.25s ease, box-shadow 0.25s ease;
  cursor: pointer;
  border: none;
}

.btn-primary:hover {
  background: var(--color-teal-light);
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(92, 224, 194, 0.25);
}

/* Scroll Indicator */
.scroll-indicator {
  position: absolute;
  bottom: var(--space-xl);
  left: 50%;
  transform: translateX(-50%);
  color: rgba(255, 255, 255, 0.3);
  animation: bounce 2s ease-in-out infinite;
  transition: opacity 0.3s ease;
}

.scroll-indicator.is-hidden {
  opacity: 0;
}

/* ============================================================
   SECTION: PROBLEM
   ============================================================ */
.section-light {
  background: var(--color-bg-light);
  padding: var(--space-section) 0;
}

.section-title {
  font-size: var(--font-size-section-title);
  font-weight: 700;
  text-align: center;
  line-height: var(--line-height-heading);
  margin-bottom: var(--space-md);
}

.section-title--dark {
  color: var(--color-text-dark);
}

.section-title--light {
  color: var(--color-white);
}

.section-title-bar {
  width: 48px;
  height: 3px;
  background: var(--color-teal);
  border-radius: 2px;
  margin: 0 auto var(--space-2xl);
}

.section-title-bar--center {
  margin-left: auto;
  margin-right: auto;
}

.problem-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

.problem-card {
  background: var(--color-card-bg);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  padding: var(--space-xl);
  text-align: center;
}

.problem-icon {
  font-size: 48px;
  line-height: 1;
  display: block;
  margin-bottom: var(--space-md);
}

.problem-card-title {
  font-size: var(--font-size-card-title);
  font-weight: 600;
  color: var(--color-text-dark);
  margin-bottom: var(--space-sm);
  line-height: var(--line-height-heading);
}

.problem-card-text {
  font-size: var(--font-size-body);
  color: var(--color-text-secondary);
  line-height: var(--line-height-body);
}

.problem-closing {
  text-align: center;
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
}

/* ============================================================
   SECTION: FEATURES
   ============================================================ */
.section-dark {
  background: var(--color-navy);
  padding: var(--space-section) 0;
}

.section-dark--mid {
  background: var(--color-navy-mid);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

.feature-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-radius: var(--radius-lg);
  padding: 36px;
  border-left: 3px solid;
  transition: border-color 0.25s ease, transform 0.25s ease, background 0.25s ease;
}

.feature-card:hover {
  border-right-color: var(--glass-border-hover);
  border-top-color: var(--glass-border-hover);
  border-bottom-color: var(--glass-border-hover);
  transform: scale(1.02);
  background: rgba(255, 255, 255, 0.06);
}

.feature-icon-wrap {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-md);
}

.feature-card-title {
  font-size: var(--font-size-card-title);
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: var(--space-sm);
  line-height: var(--line-height-heading);
}

.feature-card-text {
  font-size: var(--font-size-body);
  color: var(--color-text-light);
  line-height: var(--line-height-body);
}

/* ============================================================
   SECTION: HOW IT WORKS (Timeline)
   ============================================================ */
.timeline {
  position: relative;
  padding: var(--space-xl) 0;
}

.timeline-line {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  background: var(--color-teal);
  opacity: 0.3;
}

.timeline-item {
  position: relative;
  display: flex;
  align-items: flex-start;
  margin-bottom: var(--space-2xl);
  width: 50%;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-item--left {
  margin-right: auto;
  padding-right: 40px;
  justify-content: flex-end;
}

.timeline-item--right {
  margin-left: auto;
  padding-left: 40px;
}

.timeline-badge {
  position: absolute;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--color-teal);
  color: var(--color-navy);
  font-size: 14px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2;
  flex-shrink: 0;
}

.timeline-item--left .timeline-badge {
  right: -16px;
}

.timeline-item--right .timeline-badge {
  left: -16px;
}

.timeline-card {
  background: var(--color-card-bg);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  padding: var(--space-lg);
  max-width: 400px;
  width: 100%;
}

.timeline-card-title {
  font-size: var(--font-size-card-title);
  font-weight: 600;
  color: var(--color-text-dark);
  margin-bottom: var(--space-sm);
  line-height: var(--line-height-heading);
}

.timeline-card-text {
  font-size: var(--font-size-body);
  color: var(--color-text-secondary);
  line-height: var(--line-height-body);
}

/* ============================================================
   SECTION: DEMO
   ============================================================ */
.demo-mockup {
  margin-bottom: var(--space-2xl);
}

.mockup-frame {
  background: var(--color-navy-dark);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg), var(--shadow-glow-teal);
  max-width: 800px;
  margin: 0 auto;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.mockup-header {
  display: flex;
  align-items: center;
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.04);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  gap: 12px;
}

.mockup-dots {
  display: flex;
  gap: 6px;
}

.mockup-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.mockup-dot--red { background: #ff5f57; }
.mockup-dot--yellow { background: #febc2e; }
.mockup-dot--green { background: #28c840; }

.mockup-title {
  font-size: var(--font-size-small);
  color: var(--color-text-lighter);
  flex: 1;
  text-align: center;
}

.mockup-body {
  display: flex;
  min-height: 300px;
}

.mockup-sidebar {
  width: 50%;
  border-right: 1px solid rgba(255, 255, 255, 0.06);
  padding: var(--space-md);
}

.mockup-status {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.mockup-status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #ff4444;
  animation: cursorBlink 1.5s infinite;
}

.mockup-status-text {
  font-size: var(--font-size-small);
  color: #ff6b6b;
  font-weight: 600;
}

.mockup-log {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.mockup-log-entry {
  padding: 8px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.03);
}

.mockup-log-entry--interim {
  opacity: 0.5;
}

.mockup-log-time {
  font-size: 10px;
  color: var(--color-text-lighter);
  display: block;
  margin-bottom: 2px;
  font-family: monospace;
}

.mockup-log-text {
  font-size: 12px;
  color: var(--color-text-light);
  line-height: 1.5;
}

.mockup-main {
  width: 50%;
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.mockup-assist-card {
  border-radius: var(--radius-md);
  padding: 14px;
  border-left: 3px solid;
  background: rgba(255, 255, 255, 0.04);
}

.mockup-assist-card--teal {
  border-left-color: var(--color-teal);
}

.mockup-assist-card--purple {
  border-left-color: var(--color-purple-blue);
}

.mockup-assist-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.mockup-assist-badge {
  font-size: 11px;
  font-weight: 600;
  color: var(--color-white);
}

.mockup-assist-confidence {
  font-size: 10px;
  color: var(--color-teal);
  font-family: monospace;
}

.mockup-assist-answer {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 4px;
}

.mockup-assist-source {
  font-size: 11px;
  color: var(--color-text-lighter);
}

/* Scenario */
.demo-scenario {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.scenario-item {
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  max-width: 85%;
}

.scenario-item--user {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
  align-self: flex-start;
}

.scenario-item--kuroko {
  background: rgba(92, 224, 194, 0.08);
  border: 1px solid rgba(92, 224, 194, 0.15);
  align-self: flex-end;
}

.scenario-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 4px;
}

.scenario-item--user .scenario-label {
  color: var(--color-text-lighter);
}

.scenario-item--kuroko .scenario-label {
  color: var(--color-teal);
}

.scenario-text {
  font-size: var(--font-size-body);
  color: var(--color-text-light);
  line-height: var(--line-height-body);
}

/* ============================================================
   SECTION: ARCHITECTURE
   ============================================================ */
.arch-diagram {
  margin-bottom: var(--space-2xl);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.arch-svg {
  width: 100%;
  max-width: 900px;
  height: auto;
  margin: 0 auto;
  display: block;
}

/* Tech Stack */
.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xl);
  justify-content: center;
  margin-bottom: var(--space-2xl);
}

.tech-category {
  text-align: center;
  flex: 1;
  min-width: 200px;
}

.tech-category-title {
  font-size: var(--font-size-body);
  font-weight: 600;
  color: var(--color-text-dark);
  margin-bottom: var(--space-sm);
}

.tech-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: center;
}

.tech-badge {
  display: inline-block;
  background: rgba(92, 224, 194, 0.1);
  color: var(--color-teal);
  border: 1px solid rgba(92, 224, 194, 0.2);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  font-size: var(--font-size-small);
  font-weight: 500;
}

/* Tech Highlights */
.tech-highlights {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.tech-highlight {
  text-align: center;
  padding: var(--space-lg);
}

.tech-highlight-icon {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(92, 224, 194, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-md);
}

.tech-highlight-title {
  font-size: var(--font-size-card-title);
  font-weight: 600;
  color: var(--color-text-dark);
  margin-bottom: var(--space-sm);
  line-height: var(--line-height-heading);
}

.tech-highlight-text {
  font-size: var(--font-size-body);
  color: var(--color-text-secondary);
  line-height: var(--line-height-body);
}

/* ============================================================
   SECTION: USE CASES
   ============================================================ */
.usecases-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

.usecase-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-radius: var(--radius-lg);
  padding: 36px;
  transition: border-color 0.25s ease, transform 0.25s ease, background 0.25s ease;
}

.usecase-card:hover {
  border-color: var(--glass-border-hover);
  transform: scale(1.02);
  background: rgba(255, 255, 255, 0.06);
}

.usecase-icon {
  font-size: 40px;
  line-height: 1;
  display: block;
  margin-bottom: var(--space-md);
}

.usecase-card-title {
  font-size: var(--font-size-card-title);
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: var(--space-sm);
  line-height: var(--line-height-heading);
}

.usecase-card-text {
  font-size: var(--font-size-body);
  color: var(--color-text-light);
  line-height: var(--line-height-body);
}

/* ============================================================
   SECTION: CTA
   ============================================================ */
.section-cta {
  position: relative;
  background: linear-gradient(160deg, #1a1f36 0%, #11142a 50%, #0e1125 100%);
  padding: var(--space-section) 0;
  overflow: hidden;
}

.cta-bg-decoration {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.cta-content {
  position: relative;
  z-index: 1;
  text-align: center;
}

.cta-heading {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-white);
  line-height: var(--line-height-heading);
  margin-bottom: var(--space-lg);
}

.cta-sub {
  font-size: 1rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-xl);
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
  line-height: var(--line-height-body);
}

.cta-btn {
  margin-bottom: var(--space-lg);
  padding: 16px 48px;
}

.cta-link {
  display: inline-block;
  font-size: var(--font-size-body);
  color: var(--color-text-lighter);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.25s ease;
}

.cta-link:hover {
  color: var(--color-teal);
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--color-navy-dark);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding: var(--space-xl) 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer-logo svg {
  width: 100px;
}

.footer-copy {
  font-size: 12px;
  color: var(--color-text-lighter);
}

.footer-links {
  display: flex;
  gap: var(--space-md);
}

.footer-link {
  font-size: 12px;
  color: var(--color-text-lighter);
  transition: color 0.25s ease;
}

.footer-link:hover {
  color: var(--color-teal);
}

/* ============================================================
   RESPONSIVE: TABLET (< 1080px)
   ============================================================ */
@media (max-width: 1079px) {
  :root {
    --font-size-hero: 2.25rem;
  }

  .problem-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .tech-highlights {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ============================================================
   RESPONSIVE: MOBILE (< 768px)
   ============================================================ */
@media (max-width: 767px) {
  :root {
    --font-size-hero: 1.75rem;
    --space-section: var(--space-section-mobile);
  }

  /* Nav */
  .nav-links {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  /* Hero */
  .hero-subtitle {
    font-size: 10px;
    letter-spacing: 1px;
  }

  .hero-logo svg {
    width: 180px;
  }

  /* Grids → 1 column */
  .problem-grid,
  .features-grid,
  .usecases-grid,
  .tech-highlights {
    grid-template-columns: 1fr;
  }

  /* Timeline: single column, left-aligned */
  .timeline-line {
    left: 16px;
    transform: none;
  }

  .timeline-item {
    width: 100%;
    padding-left: 48px;
    padding-right: 0;
  }

  .timeline-item--left {
    justify-content: flex-start;
  }

  .timeline-item--left,
  .timeline-item--right {
    margin-left: 0;
    margin-right: 0;
    padding-left: 48px;
  }

  .timeline-badge {
    left: 0 !important;
    right: auto !important;
  }

  .timeline-card {
    max-width: 100%;
  }

  /* Demo mockup */
  .mockup-body {
    flex-direction: column;
  }

  .mockup-sidebar,
  .mockup-main {
    width: 100%;
  }

  .mockup-sidebar {
    border-right: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .scenario-item {
    max-width: 100%;
  }

  /* Architecture diagram */
  .arch-diagram {
    padding-bottom: var(--space-md);
  }

  .arch-svg {
    min-width: 600px;
  }

  /* CTA */
  .cta-heading {
    font-size: 1.5rem;
  }

  /* Footer */
  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

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

/* ---------- Logo as external image ---------- */
.nav-logo-svg {
  width: 120px;
  height: auto;
  display: block;
}

.hero-logo-img {
  width: 240px;
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
}

.footer-logo-img {
  width: 100px;
  height: auto;
  display: block;
  opacity: 0.5;
}

@media (max-width: 767px) {
  .hero-logo-img {
    width: 180px;
  }
}