/* Design Tokens strictly following the specified palette:
   #36ADA3 (Teal Accent)
   #2F578A (Slate Blue)
   #232F72 (Deep Navy)
   #121358 (Midnight Base)
   NO glow effects, NO glass effects, NO generic AI gradients.
*/
:root {
  --color-accent: #36ADA3;
  --color-accent-hover: #2c938b;
  --color-accent-subtle: #19464e;
  --color-slate-blue: #2F578A;
  --color-slate-blue-light: #4172af;
  --color-navy-deep: #232F72;
  --color-midnight: #121358;
  --color-midnight-dark: #0a0b33;
  --color-surface-card: #181b61;
  --color-surface-inset: #101247;
  
  --border-subtle: #242c75;
  --border-strong: #323d94;
  --border-accent: #36ADA3;

  --text-primary: #FFFFFF;
  --text-secondary: #B4BEE0;
  --text-tertiary: #7884B3;
  --text-accent: #36ADA3;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI Variable Display", "Segoe UI", Inter, Roboto, "Helvetica Neue", sans-serif;
  --font-mono: "Cascadia Code", Consolas, "SF Mono", Menlo, monospace;
  
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --container-max: 1180px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--color-midnight-dark);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: #55c7be;
}

/* Container */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* Solid Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  font-size: 14px;
  padding: 10px 18px;
  border-radius: var(--radius-md);
  cursor: pointer;
  text-decoration: none;
  transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
  white-space: nowrap;
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--color-accent);
  color: #082422;
  border-color: var(--color-accent);
}

.btn-primary:hover {
  background-color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  color: #041413;
}

.btn-secondary {
  background-color: var(--color-navy-deep);
  color: var(--text-primary);
  border-color: var(--border-strong);
}

.btn-secondary:hover {
  background-color: #2b3a8a;
  border-color: var(--color-slate-blue);
  color: var(--text-primary);
}

.btn-outline {
  background-color: transparent;
  color: var(--text-secondary);
  border-color: var(--border-subtle);
}

.btn-outline:hover {
  background-color: var(--color-midnight);
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.btn-sm {
  padding: 6px 12px;
  font-size: 13px;
}

.btn-lg {
  padding: 12px 24px;
  font-size: 15px;
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.3px;
  text-transform: uppercase;
}

.badge-accent {
  background-color: var(--color-accent-subtle);
  color: var(--color-accent);
  border: 1px solid var(--color-accent);
}

.badge-neutral {
  background-color: var(--color-midnight);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
}

/* Navbar */
.navbar {
  background-color: var(--color-midnight);
  border-bottom: 1px solid var(--border-subtle);
  position: sticky;
  top: 0;
  z-index: 100;
}

.navbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
  flex-shrink: 0;
  min-width: 0;
}

.brand-logo {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background-color: var(--color-surface-inset);
  display: block;
  flex-shrink: 0;
}

.brand-text {
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.3px;
  white-space: nowrap;
}

.brand-tag {
  font-size: 11px;
  font-weight: 600;
  color: var(--color-accent);
  background-color: var(--color-surface-inset);
  border: 1px solid var(--border-subtle);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

/* Mobile Hamburger Button */
.mobile-menu-btn {
  display: none;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background-color: var(--color-navy-deep);
  border: 1px solid var(--border-strong);
  color: var(--text-primary);
  font-size: 15px;
  cursor: pointer;
  transition: background-color 0.15s ease, border-color 0.15s ease;
}

.mobile-menu-btn:hover {
  background-color: var(--color-slate-blue);
  border-color: var(--color-accent);
}

/* Mobile Navigation Dropdown */
.mobile-nav-menu {
  display: none;
  background-color: var(--color-midnight);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-strong);
  padding: 14px 20px 18px 20px;
  flex-direction: column;
  gap: 14px;
}

.mobile-nav-menu.open {
  display: flex;
}

.mobile-nav-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.mobile-nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 14px;
  font-weight: 500;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.mobile-nav-link i {
  width: 18px;
  color: var(--color-accent);
  font-size: 13px;
}

.mobile-nav-link:hover {
  background-color: var(--color-surface-card);
  color: var(--color-accent);
}

.mobile-nav-actions {
  padding-top: 10px;
  border-top: 1px solid var(--border-subtle);
}

/* Hero Section */
.hero {
  padding: 64px 0 56px 0;
  border-bottom: 1px solid var(--border-subtle);
  background-color: var(--color-midnight);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hero-title {
  font-size: 40px;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.8px;
  color: var(--text-primary);
}

.hero-title span {
  color: var(--color-accent);
}

.hero-description {
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  margin-top: 8px;
}

.hero-spec-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--border-subtle);
  font-size: 13px;
  color: var(--text-tertiary);
}

.hero-spec-strip span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.hero-spec-strip i {
  color: var(--color-accent);
  font-size: 12px;
}

/* Hero App Mockup Frame (Crisp Solid Native Window) */
.app-frame {
  background-color: var(--color-surface-inset);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.45);
}

.app-frame-header {
  background-color: var(--color-midnight);
  border-bottom: 1px solid var(--border-subtle);
  padding: 10px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.app-frame-branding {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
}

.app-frame-pill {
  background-color: var(--color-navy-deep);
  border: 1px solid var(--border-subtle);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  font-size: 11px;
  color: var(--color-accent);
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.app-frame-controls {
  display: flex;
  gap: 8px;
  color: var(--text-tertiary);
  font-size: 11px;
}

.app-frame-body {
  display: grid;
  grid-template-columns: 140px 1fr;
  min-height: 290px;
  background-color: var(--color-surface-inset);
}

.app-frame-sidebar {
  background-color: var(--color-midnight);
  border-right: 1px solid var(--border-subtle);
  padding: 12px 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 11px;
}

.app-sidebar-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
}

.app-sidebar-item.active {
  background-color: var(--color-navy-deep);
  color: var(--text-primary);
  font-weight: 600;
  border-left: 2px solid var(--color-accent);
}

.app-sidebar-divider {
  height: 1px;
  background-color: var(--border-subtle);
  margin: 6px 0;
}

.app-frame-main {
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.app-stat-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.app-stat-card {
  background-color: var(--color-surface-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
}

.app-stat-label {
  font-size: 10px;
  color: var(--text-tertiary);
  text-transform: uppercase;
  font-weight: 600;
}

.app-stat-val {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 2px;
}

.app-vis-preview {
  background-color: var(--color-surface-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 12px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.app-vis-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 11px;
  color: var(--text-secondary);
}

.app-vis-chart-bars {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-top: 6px;
}

.vis-bar-item {
  display: grid;
  grid-template-columns: 80px 1fr 60px;
  align-items: center;
  gap: 8px;
  font-size: 11px;
}

.vis-progress {
  height: 6px;
  background-color: var(--color-surface-inset);
  border-radius: 3px;
  overflow: hidden;
}

.vis-fill {
  height: 100%;
  border-radius: 3px;
}

/* Section Structure */
.section {
  padding: 72px 0;
  border-bottom: 1px solid var(--border-subtle);
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 48px auto;
}

.section-tag {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--color-accent);
  margin-bottom: 8px;
}

.section-title {
  font-size: 30px;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-primary);
  line-height: 1.25;
  margin-bottom: 12px;
}

.section-desc {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background-color: var(--color-midnight);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: border-color 0.15s ease, background-color 0.15s ease;
}

.feature-card:hover {
  border-color: var(--border-strong);
  background-color: #161966;
}

.feature-icon-box {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background-color: var(--color-navy-deep);
  border: 1px solid var(--border-strong);
  color: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
}

.feature-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.2px;
}

.feature-body {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Visualization Deep Dive */
.vis-compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.vis-card {
  background-color: var(--color-midnight);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.vis-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 700;
  color: var(--color-accent);
}

.vis-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-primary);
}

.vis-diagram-box {
  background-color: var(--color-surface-inset);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  height: 170px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.vis-feature-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 14px;
  color: var(--text-secondary);
}

.vis-feature-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.vis-feature-list i {
  color: var(--color-accent);
  margin-top: 3px;
  font-size: 13px;
}

/* Comparison / Spec Table */
.specs-table-wrapper {
  background-color: var(--color-midnight);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow-x: auto;
}

.specs-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 14px;
}

.specs-table th {
  background-color: var(--color-surface-inset);
  padding: 14px 18px;
  font-weight: 700;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-strong);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.specs-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-secondary);
}

.specs-table tr:last-child td {
  border-bottom: none;
}

.specs-table tr:hover td {
  background-color: var(--color-surface-card);
  color: var(--text-primary);
}

.specs-table .col-highlight {
  color: var(--color-accent);
  font-weight: 600;
  font-family: var(--font-mono);
  font-size: 13px;
}

/* Download Section */
.download-section {
  background-color: var(--color-midnight);
}

.download-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  max-width: 900px;
  margin: 0 auto 36px auto;
}

.download-card {
  background-color: var(--color-surface-card);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  text-align: center;
  align-items: center;
  position: relative;
}

.download-card.featured {
  border-color: var(--color-accent);
  background-color: #19206c;
}

.download-card-tag {
  position: absolute;
  top: -11px;
  background-color: var(--color-accent);
  color: #061f1d;
  font-size: 11px;
  font-weight: 700;
  padding: 2px 10px;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.download-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background-color: var(--color-navy-deep);
  border: 1px solid var(--border-subtle);
  color: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
}

.download-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
}

.download-meta {
  font-size: 13px;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
}

.download-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.checksum-box {
  max-width: 900px;
  margin: 0 auto;
  background-color: var(--color-surface-inset);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  font-size: 12px;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.checksum-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  word-break: break-all;
  background-color: var(--color-midnight-dark);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

/* FAQ Section */
.faq-list {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  background-color: var(--color-midnight);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-question {
  padding: 18px 20px;
  font-weight: 600;
  font-size: 16px;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-question:hover {
  background-color: var(--color-surface-card);
}

.faq-question i {
  color: var(--color-accent);
  font-size: 14px;
  transition: transform 0.2s ease;
}

.faq-item.open .faq-question i {
  transform: rotate(180deg);
}

.faq-answer {
  display: none;
  padding: 0 20px 18px 20px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
  border-top: 1px solid var(--border-subtle);
  padding-top: 14px;
}

.faq-item.open .faq-answer {
  display: block;
}

/* Footer */
.footer {
  background-color: var(--color-midnight-dark);
  border-top: 1px solid var(--border-subtle);
  padding: 48px 0 32px 0;
  font-size: 13px;
  color: var(--text-tertiary);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 36px;
  margin-bottom: 36px;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col-title {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-links a {
  color: var(--text-secondary);
}

.footer-links a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

/* Responsive */
@media (max-width: 900px) {
  .nav-desktop {
    display: none;
  }
  .mobile-menu-btn {
    display: inline-flex;
  }
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }
  .features-grid {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }
  .vis-compare-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .download-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 640px) {
  .container {
    padding: 0 16px;
  }
  .hero {
    padding: 40px 0 36px 0;
  }
  .hero-title {
    font-size: 28px;
    line-height: 1.2;
    letter-spacing: -0.4px;
  }
  .hero-description {
    font-size: 15px;
    line-height: 1.55;
  }
  .hero-actions {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
  }
  .hero-actions .btn {
    width: 100%;
    justify-content: center;
  }
  .hero-spec-strip {
    gap: 10px 14px;
    font-size: 12px;
  }
  .app-frame-body {
    grid-template-columns: 1fr;
  }
  .app-frame-sidebar {
    display: none;
  }
  .app-frame-main {
    padding: 14px;
    gap: 10px;
  }
  .app-stat-row {
    grid-template-columns: 1fr;
    gap: 8px;
  }
  .section {
    padding: 52px 0;
  }
  .section-header {
    margin-bottom: 32px;
  }
  .section-title {
    font-size: 24px;
    line-height: 1.25;
  }
  .section-desc {
    font-size: 15px;
  }
  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .feature-card {
    padding: 20px 18px;
  }
  .vis-card {
    padding: 22px 18px;
  }
  .vis-title {
    font-size: 20px;
  }
  .specs-table-wrapper {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  .specs-table {
    min-width: 520px;
    font-size: 13px;
  }
  .download-card {
    padding: 28px 18px;
  }
  .checksum-box {
    padding: 14px 16px;
    font-size: 11px;
  }
  .checksum-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
    padding: 10px 12px;
    word-break: break-all;
  }
  .faq-question {
    padding: 16px 18px;
    font-size: 15px;
  }
  .faq-answer {
    padding: 0 18px 16px 18px;
    font-size: 14px;
  }
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
}

/* Small mobile devices (e.g. 360px - 440px phones) */
@media (max-width: 480px) {
  .navbar-inner {
    height: 58px;
  }
  .brand-tag {
    display: none;
  }
  .brand-text {
    font-size: 16px;
  }
  .brand-logo {
    width: 28px;
    height: 28px;
  }
  .nav-actions {
    gap: 6px;
  }
  .nav-btn-github .nav-btn-text {
    display: none;
  }
  .nav-btn-github {
    padding: 7px 10px;
    font-size: 13px;
  }
  .nav-btn-download {
    padding: 7px 10px;
    font-size: 12px;
  }
  .mobile-menu-btn {
    width: 34px;
    height: 34px;
    font-size: 13px;
  }
  .hero-title {
    font-size: 24px;
    line-height: 1.22;
    letter-spacing: -0.3px;
  }
  .badge {
    font-size: 10.5px;
    padding: 4px 8px;
  }
  .vis-diagram-box {
    height: 130px;
  }
  .vis-diagram-box svg {
    max-width: 100%;
    height: auto;
    max-height: 110px;
  }
  .vis-bar-item {
    grid-template-columns: 75px 1fr 45px;
    font-size: 10.5px;
    gap: 6px;
  }
}