/* ==========================================================================
   Google Developer Groups • Professional 16:9 Keynote Presentation Deck
   Follows Google Material Design 3 tokens, WCAG AA 2.2, and Antislop rules.
   ========================================================================== */

:root {
  /* Light & Dark Palette Tokens (WCAG AA verified via contrast-check.py) */
  --bg-backdrop-light: #eef3fc;
  --bg-backdrop-dark: #0d0e11;

  --bg-slide-light: #ffffff;
  --bg-slide-dark: #131314;

  --bg-surface-light: #f8fafd;
  --bg-surface-dark: #1e1f20;

  --bg-surface-alt-light: #edf2fa;
  --bg-surface-alt-dark: #282a2c;

  --text-primary-light: #1f1f1f;
  --text-primary-dark: #e3e3e3;

  --text-secondary-light: #444746;
  --text-secondary-dark: #c4c7c5;

  /* Core Color 1: Google Material 3 Primary Blue */
  --color-primary-light: #0b57d0;
  --color-primary-dark: #a8c7fa;

  --color-on-primary-light: #ffffff;
  --color-on-primary-dark: #062e6f;

  --color-primary-tint-light: #e8f0fe;
  --color-primary-tint-dark: #0842a0;

  --color-on-primary-tint-light: #0b57d0;
  --color-on-primary-tint-dark: #d3e3fd;

  /* Core Color 2: Google Material 3 Functional Green */
  --color-success-light: #137333;
  --color-success-dark: #81c995;

  --color-success-tint-light: #e6f4ea;
  --color-success-tint-dark: #0d5223;

  /* Deliberate Accent: Google Amber */
  --color-accent-light: #754200;
  --color-accent-dark: #fdd663;

  --color-accent-tint-light: #fef7e0;
  --color-accent-tint-dark: #422c00;

  /* Borders (3:1+ contrast for interactive boundaries) */
  --border-strong-light: #747775;
  --border-strong-dark: #8e918f;

  --border-subtle-light: #c4c7c5;
  --border-subtle-dark: #444746;

  /* Fallback Assignments */
  --bg-backdrop: var(--bg-backdrop-light);
  --bg-page: var(--bg-slide-light);
  --bg-surface: var(--bg-surface-light);
  --bg-surface-alt: var(--bg-surface-alt-light);
  --text-primary: var(--text-primary-light);
  --text-secondary: var(--text-secondary-light);
  --color-primary: var(--color-primary-light);
  --color-on-primary: var(--color-on-primary-light);
  --color-primary-tint: var(--color-primary-tint-light);
  --color-on-primary-tint: var(--color-on-primary-tint-light);
  --color-success: var(--color-success-light);
  --color-success-tint: var(--color-success-tint-light);
  --color-accent: var(--color-accent-light);
  --color-accent-tint: var(--color-accent-tint-light);
  --border-strong: var(--border-strong-light);
  --border-subtle: var(--border-subtle-light);

  /* Radii Hierarchy (R-11) */
  --radius-slide: 20px;
  --radius-card: 14px;
  --radius-control: 8px;

  --font-sans: "Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  color-scheme: light dark;
  accent-color: var(--color-primary);

  @media (prefers-color-scheme: dark) {
    --bg-backdrop: var(--bg-backdrop-dark);
    --bg-page: var(--bg-slide-dark);
    --bg-surface: var(--bg-surface-dark);
    --bg-surface-alt: var(--bg-surface-alt-dark);
    --text-primary: var(--text-primary-dark);
    --text-secondary: var(--text-secondary-dark);
    --color-primary: var(--color-primary-dark);
    --color-on-primary: var(--color-on-primary-dark);
    --color-primary-tint: var(--color-primary-tint-dark);
    --color-on-primary-tint: var(--color-on-primary-tint-dark);
    --color-success: var(--color-success-dark);
    --color-success-tint: var(--color-success-tint-dark);
    --color-accent: var(--color-accent-dark);
    --color-accent-tint: var(--color-accent-tint-dark);
    --border-strong: var(--border-strong-dark);
    --border-subtle: var(--border-subtle-dark);
  }

  &:has(> head > meta[name="color-scheme"][content="dark"]) {
    color-scheme: dark;
    --bg-backdrop: var(--bg-backdrop-dark);
    --bg-page: var(--bg-slide-dark);
    --bg-surface: var(--bg-surface-dark);
    --bg-surface-alt: var(--bg-surface-alt-dark);
    --text-primary: var(--text-primary-dark);
    --text-secondary: var(--text-secondary-dark);
    --color-primary: var(--color-primary-dark);
    --color-on-primary: var(--color-on-primary-dark);
    --color-primary-tint: var(--color-primary-tint-dark);
    --color-on-primary-tint: var(--color-on-primary-tint-dark);
    --color-success: var(--color-success-dark);
    --color-success-tint: var(--color-success-tint-dark);
    --color-accent: var(--color-accent-dark);
    --color-accent-tint: var(--color-accent-tint-dark);
    --border-strong: var(--border-strong-dark);
    --border-subtle: var(--border-subtle-dark);
  }

  &:has(> head > meta[name="color-scheme"][content="light"]) {
    color-scheme: light;
    --bg-backdrop: var(--bg-backdrop-light);
    --bg-page: var(--bg-slide-light);
    --bg-surface: var(--bg-surface-light);
    --bg-surface-alt: var(--bg-surface-alt-light);
    --text-primary: var(--text-primary-light);
    --text-secondary: var(--text-secondary-light);
    --color-primary: var(--color-primary-light);
    --color-on-primary: var(--color-on-primary-light);
    --color-primary-tint: var(--color-primary-tint-light);
    --color-on-primary-tint: var(--color-on-primary-tint-light);
    --color-success: var(--color-success-light);
    --color-success-tint: var(--color-success-tint-light);
    --color-accent: var(--color-accent-light);
    --color-accent-tint: var(--color-accent-tint-light);
    --border-strong: var(--border-strong-light);
    --border-subtle: var(--border-subtle-light);
  }

  @supports (color: light-dark(white, black)) {
    --bg-backdrop: light-dark(var(--bg-backdrop-light), var(--bg-backdrop-dark));
    --bg-page: light-dark(var(--bg-slide-light), var(--bg-slide-dark));
    --bg-surface: light-dark(var(--bg-surface-light), var(--bg-surface-dark));
    --bg-surface-alt: light-dark(var(--bg-surface-alt-light), var(--bg-surface-alt-dark));
    --text-primary: light-dark(var(--text-primary-light), var(--text-primary-dark));
    --text-secondary: light-dark(var(--text-secondary-light), var(--text-secondary-dark));
    --color-primary: light-dark(var(--color-primary-light), var(--color-primary-dark));
    --color-on-primary: light-dark(var(--color-on-primary-light), var(--color-on-primary-dark));
    --color-primary-tint: light-dark(var(--color-primary-tint-light), var(--color-primary-tint-dark));
    --color-on-primary-tint: light-dark(var(--color-on-primary-tint-light), var(--color-on-primary-tint-dark));
    --color-success: light-dark(var(--color-success-light), var(--color-success-dark));
    --color-success-tint: light-dark(var(--color-success-tint-light), var(--color-success-tint-dark));
    --color-accent: light-dark(var(--color-accent-light), var(--color-accent-dark));
    --color-accent-tint: light-dark(var(--color-accent-tint-light), var(--color-accent-tint-dark));
    --border-strong: light-dark(var(--border-strong-light), var(--border-strong-dark));
    --border-subtle: light-dark(var(--border-subtle-light), var(--border-subtle-dark));
  }
}

/* Theme Toggle State Branching */
.theme-option-light {
  display: none;
}
.theme-option-dark {
  display: inline;
}

@media (prefers-color-scheme: dark) {
  :root:not(:has(> head > meta[name="color-scheme"][content="light"])) .theme-option-dark {
    display: none;
  }
  :root:not(:has(> head > meta[name="color-scheme"][content="light"])) .theme-option-light {
    display: inline;
  }
}

:root:has(> head > meta[name="color-scheme"][content="dark"]) .theme-option-dark {
  display: none;
}
:root:has(> head > meta[name="color-scheme"][content="dark"]) .theme-option-light {
  display: inline;
}

/* ==========================================================================
   Reset & Base Layer Affordances (R-39, R-32)
   ========================================================================== */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100dvh;
  background-color: var(--bg-backdrop);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
}

/* Base-layer pointer cursor for all enabled interactive controls (R-39) */
a[href],
button:not(:disabled),
summary,
select:not(:disabled),
label[for],
input:not(:disabled),
[role="button"]:not([aria-disabled="true"]),
[role="tab"]:not([aria-disabled="true"]) {
  cursor: pointer;
}

button:disabled,
select:disabled,
input:disabled,
[aria-disabled="true"] {
  cursor: not-allowed;
  opacity: 0.55;
}

:where(a:any-link, button, input, select, textarea, summary, [tabindex="0"]):focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 3px;
}

.visually-hidden:where(:not(:focus-within, :active)) {
  position: absolute !important;
  clip-path: inset(50%) !important;
  overflow: hidden !important;
  width: 1px !important;
  height: 1px !important;
  margin: -1px !important;
  padding: 0 !important;
  border: 0 !important;
  white-space: nowrap !important;
}

.skip-link:focus-visible {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 1000;
  background: var(--color-primary);
  color: var(--color-on-primary);
  padding: 10px 16px;
  border-radius: var(--radius-control);
  font-weight: 600;
  text-decoration: none;
}

/* ==========================================================================
   Directional Navigation View Transitions (modern-web-guidance)
   ========================================================================== */

@keyframes slide-to-left {
  to {
    transform: translateX(-40px);
    opacity: 0;
  }
}

@keyframes slide-from-right {
  from {
    transform: translateX(40px);
    opacity: 0;
  }
}

@keyframes slide-to-right {
  to {
    transform: translateX(40px);
    opacity: 0;
  }
}

@keyframes slide-from-left {
  from {
    transform: translateX(-40px);
    opacity: 0;
  }
}

::view-transition-group(root) {
  animation: 0.32s cubic-bezier(0.22, 1, 0.36, 1) both;
}

html:active-view-transition-type(forward)::view-transition-old(root) {
  animation-name: slide-to-left;
}

html:active-view-transition-type(forward)::view-transition-new(root) {
  animation-name: slide-from-right;
}

html:active-view-transition-type(backward)::view-transition-old(root) {
  animation-name: slide-to-right;
}

html:active-view-transition-type(backward)::view-transition-new(root) {
  animation-name: slide-from-left;
}

@media (prefers-reduced-motion: reduce) {
  ::view-transition-group(root) {
    animation: none !important;
  }
}

/* ==========================================================================
   Centered 16:9 Presentation Stage & Fixed Logical 1600x900 Canvas
   ========================================================================== */

.presentation-stage-shell {
  width: 100%;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: 16px 24px;
}

.slide-frame-16x9 {
  position: relative;
  width: var(--frame-w, min(100%, 1360px));
  height: var(--frame-h, auto);
  aspect-ratio: 16 / 9;
  background-color: var(--bg-page);
  border: 1.5px solid var(--border-strong);
  border-radius: var(--radius-slide);
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.14);
  flex-shrink: 0;
}

/* Subtle Google 4-color top accent strip inside the 16:9 slide */
.slide-frame-16x9::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  z-index: 10;
  background: linear-gradient(
    90deg,
    #4285f4 0% 25%,
    #ea4335 25% 50%,
    #fbbc04 50% 75%,
    #34a853 75% 100%
  );
}

.slide-canvas-inner {
  width: 1600px;
  height: 900px;
  transform: scale(var(--slide-scale, 0.85));
  transform-origin: top left;
  padding: 44px 56px 40px 56px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background-color: var(--bg-page);
}

/* Top Watermark inside Slide */
.slide-top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

.gdg-badge {
  display: flex;
  align-items: center;
  gap: 12px;
}

.gdg-badge-text {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-secondary);
  letter-spacing: -0.01em;
}

.slide-page-pill {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-on-primary-tint);
  background-color: var(--color-primary-tint);
  padding: 6px 16px;
  border-radius: var(--radius-control);
}

/* Main 2-Column Slide Grid inside 1600x900 */
.slide-body-grid {
  flex: 1;
  min-height: 0;
  padding-top: 28px;
  display: grid;
  grid-template-columns: 1.28fr 0.92fr;
  gap: 44px;
  align-items: stretch;
}

.slides-content-area {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-width: 0;
}

.slide {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 22px;
}

.slide[hidden] {
  display: none !important;
}

/* ==========================================================================
   Keynote Slide Typography (Big, Scannable, Effortless to Read)
   ========================================================================== */

.slide-kicker {
  display: inline-block;
  align-self: flex-start;
  font-size: 0.96rem;
  font-weight: 700;
  color: var(--color-primary);
  background-color: var(--color-primary-tint);
  padding: 6px 14px;
  border-radius: var(--radius-control);
  white-space: nowrap;
}

.display-title {
  margin: 0;
  font-size: 3.15rem;
  line-height: 1.12;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  text-wrap: balance;
}

.display-subtitle {
  margin: 0;
  font-size: 1.25rem;
  line-height: 1.48;
  color: var(--text-secondary);
  max-width: 56ch;
}

/* Fun Fact Callout on Slide 1 */
.fun-fact-banner {
  display: flex;
  align-items: center;
  gap: 14px;
  background-color: var(--color-primary-tint);
  border: 1.5px solid var(--color-primary);
  border-radius: var(--radius-card);
  padding: 12px 18px;
}

.fun-fact-badge {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  padding: 5px 10px;
  border-radius: 6px;
  white-space: nowrap;
  flex-shrink: 0;
}

.fun-fact-text {
  margin: 0;
  font-size: 1.02rem;
  line-height: 1.42;
  color: var(--color-on-primary-tint);
}

.slide-title {
  margin: 0;
  font-size: 2.5rem;
  line-height: 1.16;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  text-wrap: balance;
}

.slide-lead {
  margin: 0;
  font-size: 1.2rem;
  line-height: 1.5;
  color: var(--text-secondary);
  max-width: 60ch;
}

/* 3D Perspective Tilt Effect on Slide Cards */
.tilt-card {
  transform: perspective(900px) rotateX(var(--tilt-x, 0deg)) rotateY(var(--tilt-y, 0deg));
  transition: transform 0.18s ease-out, border-color 0.18s ease;
}

.tilt-card:hover {
  border-color: var(--color-primary);
}

/* ==========================================================================
   Slide Components (Spacious & Visual)
   ========================================================================== */

/* Slide 1: 3 Pillars */
.cover-pillars {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-top: 2px;
}

.mini-pillar {
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 18px 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.pillar-num {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-primary);
  white-space: nowrap;
}

.mini-pillar strong {
  font-size: 1.08rem;
  color: var(--text-primary);
  white-space: nowrap;
}

.mini-pillar span:last-child {
  font-size: 0.94rem;
  line-height: 1.42;
  color: var(--text-secondary);
}

/* Slide 2: Compare Cards */
.compare-cards-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
  margin-top: 6px;
}

.compare-card {
  border-radius: var(--radius-card);
  padding: 28px 26px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.compare-card.is-muted {
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-subtle);
}

.compare-card.is-featured {
  background-color: var(--color-primary-tint);
  border: 2px solid var(--color-primary);
}

.card-tag {
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 6px;
  background-color: var(--bg-page);
  color: var(--text-primary);
  white-space: nowrap;
}

.compare-card h3 {
  margin: 0;
  font-size: 1.38rem;
  color: var(--text-primary);
  white-space: nowrap;
}

.compare-card p {
  margin: 0;
  font-size: 1.06rem;
  line-height: 1.5;
  color: var(--text-secondary);
}

.compare-card.is-featured h3,
.compare-card.is-featured p {
  color: var(--color-on-primary-tint);
}

/* Slide 3: Benefit Switcher & 3 Cards */
.interactive-switch-row {
  display: flex;
  gap: 12px;
}

.switch-pill {
  min-block-size: 48px;
  padding: 10px 24px;
  border-radius: var(--radius-control);
  border: 1.5px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 1.05rem;
  font-weight: 700;
  white-space: nowrap;
}

.switch-pill.is-active {
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  border-color: var(--color-primary);
}

.benefit-cards-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.benefit-cards-grid[hidden] {
  display: none !important;
}

.point-card {
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.point-card strong {
  font-size: 1.14rem;
  color: var(--text-primary);
  white-space: nowrap;
}

.point-card p {
  margin: 0;
  font-size: 1rem;
  line-height: 1.46;
  color: var(--text-secondary);
}

/* Slide 4: 3 Steps of Vibe Coding */
.step-cards-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.step-card {
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 26px 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.step-badge {
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--color-primary);
  background-color: var(--color-primary-tint);
  padding: 4px 10px;
  border-radius: 6px;
  white-space: nowrap;
}

.step-card h3 {
  margin: 0;
  font-size: 1.22rem;
  color: var(--text-primary);
  white-space: nowrap;
}

.step-card p {
  margin: 0;
  font-size: 1.02rem;
  line-height: 1.48;
  color: var(--text-secondary);
}

/* Slide 5: 3 Layer Buttons of Gemini Canvas */
.layer-buttons-stack {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.layer-select-btn {
  width: 100%;
  text-align: left;
  padding: 18px 22px;
  border-radius: var(--radius-card);
  border: 1.5px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  font-family: var(--font-sans);
  display: flex;
  align-items: center;
  gap: 18px;
}

.layer-select-btn.is-active {
  background-color: var(--color-primary-tint);
  color: var(--color-on-primary-tint);
  border-color: var(--color-primary);
}

.layer-dot {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.layer-select-btn strong {
  display: block;
  font-size: 1.18rem;
  margin-bottom: 4px;
}

.layer-select-btn span:last-child {
  display: block;
  font-size: 1rem;
  color: var(--text-secondary);
}

.layer-select-btn.is-active span:last-child {
  color: var(--color-on-primary-tint);
}

/* Slide 6: .html Features & Download Button */
.html-feature-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.html-feature-item {
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 24px 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.html-feature-item strong {
  font-size: 1.25rem;
  color: var(--text-primary);
}

.html-feature-item p {
  margin: 0;
  font-size: 1.05rem;
  color: var(--text-secondary);
}

.slide-action-strip {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.action-btn-secondary {
  min-block-size: 48px;
  padding: 12px 22px;
  border-radius: var(--radius-control);
  border: 1.5px solid var(--color-primary);
  background-color: var(--color-primary-tint);
  color: var(--color-on-primary-tint);
  font-family: var(--font-sans);
  font-size: 1.02rem;
  font-weight: 700;
}

.status-inline {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--color-success);
}

/* Slide 7: 4 Recipe Cards */
.recipe-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.recipe-card {
  text-align: left;
  padding: 18px 16px;
  border-radius: var(--radius-card);
  border: 1.5px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  font-family: var(--font-sans);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.recipe-card.is-active {
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  border-color: var(--color-primary);
}

.recipe-num {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
}

.recipe-card strong {
  font-size: 1.15rem;
}

.recipe-card span:last-child {
  font-size: 0.92rem;
  opacity: 0.88;
}

.prompt-preview-banner {
  background-color: var(--bg-surface);
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-card);
  padding: 20px 24px;
}

.prompt-banner-label {
  display: block;
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 6px;
}

.prompt-preview-banner p {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 1.08rem;
  color: var(--text-primary);
}

/* Slide 8: Clean Interactive Mini Demo */
.demo-Interactive-box {
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.demo-preset-bar {
  display: flex;
  align-items: center;
  gap: 14px;
}

.demo-select-label {
  font-weight: 700;
  font-size: 1.02rem;
}

.demo-select {
  min-block-size: 44px;
  padding: 8px 16px;
  border-radius: var(--radius-control);
  border: 1.5px solid var(--border-strong);
  background-color: var(--bg-page);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
}

.demo-split-cards {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 18px;
}

.demo-prompt-side,
.demo-app-side {
  background-color: var(--bg-page);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 18px;
}

.side-label {
  display: block;
  font-size: 0.86rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.mono-prompt-text {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.96rem;
  line-height: 1.55;
  color: var(--text-primary);
}

.mini-calc-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 12px;
}

.mini-calc-row label {
  display: block;
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

.mini-calc-row input {
  width: 100%;
  min-block-size: 40px;
  padding: 6px 10px;
  border-radius: 6px;
  border: 1px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.96rem;
  font-weight: 600;
}

.mini-calc-result {
  background-color: var(--color-success-tint);
  color: var(--color-success);
  padding: 12px 14px;
  border-radius: 8px;
  font-weight: 700;
  font-size: 1rem;
}

/* Slide 9: Iterative Steps */
.iter-pills-row {
  display: flex;
  gap: 12px;
}

.iter-pill {
  min-block-size: 48px;
  padding: 10px 22px;
  border-radius: var(--radius-control);
  border: 1.5px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 1.02rem;
  font-weight: 700;
}

.iter-pill.is-active {
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  border-color: var(--color-primary);
}

.iter-detail-card {
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 28px 26px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.iter-kicker {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-primary);
}

.iter-detail-card h3 {
  margin: 0;
  font-size: 1.45rem;
}

.iter-detail-card p {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 1.08rem;
  color: var(--text-secondary);
  background-color: var(--bg-page);
  padding: 14px 18px;
  border-radius: 8px;
  border: 1px solid var(--border-subtle);
}

/* Slide 10: CanvasCraft Sprint Themes */
.sprint-themes-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.sprint-theme-card {
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* Deliberate Amber Award Tag */
.sprint-tag {
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  background-color: var(--color-accent-tint);
  color: var(--color-accent);
  padding: 4px 10px;
  border-radius: 6px;
}

.sprint-theme-card h3 {
  margin: 0;
  font-size: 1.32rem;
}

.sprint-theme-card p {
  margin: 0;
  font-size: 1.02rem;
  color: var(--text-secondary);
}

.sprint-journey-bar {
  display: flex;
  align-items: center;
  gap: 16px;
  background-color: var(--color-primary-tint);
  color: var(--color-on-primary-tint);
  padding: 14px 20px;
  border-radius: var(--radius-card);
}

.journey-title {
  font-size: 1.02rem;
  font-weight: 800;
  white-space: nowrap;
  flex-shrink: 0;
}

.journey-steps-list {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  min-width: 0;
}

.journey-step-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  flex: 1 1 0;
  justify-content: center;
  background-color: var(--bg-page);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-control);
  padding: 8px 10px;
  font-size: 0.94rem;
  font-weight: 600;
  white-space: nowrap;
}

.journey-step-pill strong {
  color: var(--color-primary);
  font-family: var(--font-mono);
}

/* ==========================================================================
   Right Column inside Slide: 3D Decorative & Interactive Stage
   ========================================================================== */

.slide-visual-3d {
  height: 100%;
  min-height: 0;
  display: flex;
  flex-direction: column;
}

.visual-3d-card {
  flex: 1;
  min-height: 0;
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 12px;
}

.visual-3d-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.visual-3d-badge {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--color-primary);
}

.canvas-3d-holder {
  flex: 1;
  min-height: 0;
  background-color: var(--bg-page);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  overflow: hidden;
  position: relative;
}

#canvas-3d {
  width: 100%;
  height: 100%;
  display: block;
  cursor: grab;
  touch-action: pan-y;
}

#canvas-3d:active {
  cursor: grabbing;
}

.visual-3d-hint {
  margin: 0;
  font-size: 0.92rem;
  color: var(--text-secondary);
  text-align: center;
}

/* ==========================================================================
   Bottom Navigation Bar Directly Underneath the 16:9 Slide Frame
   ========================================================================== */

.deck-bottom-bar {
  width: var(--frame-w, min(100%, 1360px));
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  background-color: var(--bg-page);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 8px 14px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.06);
  flex-shrink: 0;
}

.nav-pill-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-block-size: 44px;
  min-inline-size: 44px;
  padding: 8px 18px;
  border-radius: var(--radius-control);
  border: 1px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 700;
}

.nav-pill-btn:hover:not([aria-disabled="true"]) {
  background-color: var(--color-primary-tint);
  color: var(--color-on-primary-tint);
  border-color: var(--color-primary);
}

.nav-pill-primary {
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  border-color: var(--color-primary);
}

.nav-pill-primary:hover:not([aria-disabled="true"]) {
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  filter: brightness(1.08);
}

.bottom-center-status {
  display: flex;
  align-items: center;
  gap: 14px;
}

.mini-dots {
  display: flex;
  align-items: center;
  gap: 6px;
}

.dot-btn {
  width: 24px;
  height: 24px;
  padding: 0;
  border: 0;
  background: transparent;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.dot-btn::after {
  content: "";
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background-color: var(--border-strong);
  transition: transform 0.15s ease, background-color 0.15s ease;
}

.dot-btn.is-active::after {
  background-color: var(--color-primary);
  transform: scale(1.35);
}

.slide-num-text {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.bottom-right-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.icon-util-btn {
  min-block-size: 44px;
  padding: 8px 12px;
  border-radius: var(--radius-control);
  border: 1px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 600;
}

.icon-util-btn:hover {
  border-color: var(--color-primary);
}

.deck-bottom-bar {
  flex-wrap: nowrap;
}

.slide-num-text {
  white-space: nowrap;
}

.nav-pill-btn {
  white-space: nowrap;
}

/* Phones (portrait) and short landscape screens: compact single-row controls */
@media (max-width: 768px), (max-height: 560px) {
  .presentation-stage-shell {
    padding: 8px;
    gap: 8px;
  }

  .mini-dots,
  .icon-util-btn {
    display: none;
  }

  .deck-bottom-bar {
    padding: 4px 8px;
    gap: 8px;
  }

  .bottom-center-status {
    flex: 1;
    justify-content: center;
  }

  .nav-pill-btn {
    min-block-size: 40px;
    padding: 6px 14px;
    font-size: 0.84rem;
  }
}

@media (max-height: 560px) and (orientation: landscape) {
  .presentation-stage-shell {
    padding: 6px 8px;
    gap: 6px;
  }
}