/* =============================================================
   DEVFLUENTIA — SECTION 4.2: REPLACING INFORMAL EXPRESSIONS
   ELEGANT UNIVERSITY PRESENTATION DESIGN SYSTEM (PDF-BASED)
   Scope: .rie-pres-wrapper
   ============================================================= */

/* ── 01. WRAPPER & SUBTLE AMBIENT BACKGROUND ── */
.rie-pres-wrapper {
  position: relative;
  min-height: calc(100vh - 80px);
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  align-items: center;
  padding: 24px 20px 80px;
  background-color: #F8FAFC;
  font-family: var(--font-sans, 'Inter', -apple-system, BlinkMacSystemFont, sans-serif);
  color: #1E293B;
  box-sizing: border-box;
}

.rie-pres-wrapper *,
.rie-pres-wrapper *::before,
.rie-pres-wrapper *::after {
  box-sizing: border-box;
}

/* Subtle Animated Academic Background */
.rie-pres-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
  background: #F8FAFC;
}

.rie-pres-subtle-grid {
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(to right, rgba(30, 58, 138, 0.03) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30, 58, 138, 0.03) 1px, transparent 1px);
  background-size: 36px 36px;
}

.rie-pres-ambient-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  pointer-events: none;
  opacity: 0.85;
  will-change: transform;
}

.rie-glow-orb-1 {
  width: 580px;
  height: 580px;
  top: -80px;
  right: -60px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.07) 0%, rgba(37, 99, 235, 0.02) 60%, transparent 75%);
  animation: rieOrbFloat1 24s ease-in-out infinite alternate;
}

.rie-glow-orb-2 {
  width: 520px;
  height: 520px;
  bottom: -60px;
  left: -80px;
  background: radial-gradient(circle, rgba(217, 119, 6, 0.05) 0%, rgba(184, 154, 98, 0.02) 60%, transparent 75%);
  animation: rieOrbFloat2 28s ease-in-out infinite alternate;
}

.rie-glow-orb-3 {
  width: 440px;
  height: 440px;
  top: 40%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle, rgba(30, 58, 138, 0.03) 0%, transparent 70%);
  animation: rieOrbFloat3 20s ease-in-out infinite alternate;
}

@keyframes rieOrbFloat1 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-30px, 40px) scale(1.08); }
  100% { transform: translate(25px, -20px) scale(0.95); }
}

@keyframes rieOrbFloat2 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(40px, -35px) scale(1.06); }
  100% { transform: translate(-20px, 20px) scale(0.96); }
}

@keyframes rieOrbFloat3 {
  0% { transform: translate(-50%, -50%) scale(1); }
  50% { transform: translate(-45%, -55%) scale(1.1); }
  100% { transform: translate(-55%, -45%) scale(0.92); }
}

/* ── 02. MAIN CONTAINER & TOP HEADER ── */
.rie-pres-container {
  position: relative;
  z-index: 10;
  width: 100%;
  max-width: 1080px;
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

.rie-top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 20px;
  margin-bottom: 24px;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(226, 232, 240, 0.8);
  border-radius: 14px;
  box-shadow: 0 4px 18px rgba(15, 23, 42, 0.04);
}

.rie-top-breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  font-weight: 500;
  color: #64748B;
}

.rie-top-link {
  color: #475569;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  transition: color 0.18s ease;
}

.rie-top-link:hover {
  color: #1E3A8A;
}

.rie-top-sep {
  color: #CBD5E1;
}

.rie-top-current {
  color: #1E3A8A;
  font-weight: 700;
}

.rie-progress-pill {
  display: flex;
  align-items: center;
  gap: 12px;
}

.rie-progress-text {
  font-family: 'Manrope', sans-serif;
  font-size: 0.85rem;
  font-weight: 700;
  color: #1E3A8A;
  letter-spacing: 0.04em;
}

.rie-progress-track {
  width: 100px;
  height: 6px;
  background: #E2E8F0;
  border-radius: 999px;
  overflow: hidden;
}

.rie-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #2563EB 0%, #1E3A8A 100%);
  border-radius: 999px;
  transition: width 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ── 03. SCREEN VIEWPORT & SLIDES ── */
.rie-screen-viewport {
  width: 100%;
  min-height: 580px;
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 24px;
  padding: 44px 48px;
  box-shadow: 0 12px 40px rgba(15, 23, 42, 0.05);
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.animate-fade-in {
  animation: rieFadeIn 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes rieFadeIn {
  0% { opacity: 0; transform: translateY(14px); }
  100% { opacity: 1; transform: translateY(0); }
}

/* ── 04. INTRO SLIDE (SCREEN 0) ── */
.rie-slide-intro {
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

.rie-intro-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  align-self: flex-start;
  background: rgba(30, 58, 138, 0.06);
  border: 1px solid rgba(30, 58, 138, 0.16);
  color: #1E3A8A;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 6px 14px;
  border-radius: 20px;
  margin-bottom: 20px;
}

.rie-intro-title {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: clamp(2.2rem, 4vw, 3.2rem);
  font-weight: 700;
  color: #0F172A;
  line-height: 1.2;
  margin: 0 0 28px;
  letter-spacing: -0.02em;
}

.rie-title-highlight {
  color: #1E3A8A;
  font-style: italic;
  font-weight: 600;
}

.rie-intro-card {
  border-radius: 14px;
  padding: 22px 26px;
  margin-bottom: 18px;
  box-shadow: 0 4px 14px rgba(15, 23, 42, 0.02);
}

.rie-intro-def-card {
  background: #F8FAFC;
  border-left: 4px solid #2563EB;
  border-top: 1px solid #E2E8F0;
  border-right: 1px solid #E2E8F0;
  border-bottom: 1px solid #E2E8F0;
}

.rie-intro-matter-card {
  background: #FFFDF9;
  border-left: 4px solid #B45309;
  border-top: 1px solid #FDE68A;
  border-right: 1px solid #FDE68A;
  border-bottom: 1px solid #FDE68A;
}

.rie-card-badge {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.rie-intro-def-card .rie-card-badge { color: #1E3A8A; }
.rie-intro-matter-card .rie-card-badge { color: #B45309; }

.rie-intro-def-text {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 1.18rem;
  line-height: 1.6;
  color: #1E293B;
  margin: 0;
}

.rie-intro-matter-text {
  font-size: 1.02rem;
  line-height: 1.65;
  color: #334155;
  margin: 0;
}

.rie-characteristics-section {
  margin: 18px 0 26px;
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 16px;
  padding: 22px 26px;
}

.rie-section-subhead {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: 'Manrope', sans-serif;
  font-size: 0.88rem;
  font-weight: 800;
  color: #0F172A;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.rie-char-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px 24px;
}

.rie-char-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.94rem;
  line-height: 1.5;
  color: #334155;
}

.rie-char-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #2563EB;
  margin-top: 7px;
  flex-shrink: 0;
}

.rie-char-label {
  color: #0F172A;
  font-weight: 700;
  margin-right: 4px;
}

.rie-intro-example-banner {
  background: #F1F5F9;
  border: 1px solid #CBD5E1;
  border-radius: 14px;
  padding: 16px 20px;
  margin-bottom: 28px;
}

.rie-ex-pill {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #475569;
  margin-bottom: 10px;
}

.rie-intro-ex-duo {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.rie-ex-side {
  flex: 1;
  padding: 12px 16px;
  border-radius: 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.rie-ex-informal {
  background: #FEF2F2;
  border: 1px solid #FECACA;
}

.rie-ex-formal {
  background: #EFF6FF;
  border: 1px solid #BFDBFE;
}

.rie-side-tag {
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.rie-ex-informal .rie-side-tag { color: #DC2626; }
.rie-ex-formal .rie-side-tag { color: #2563EB; }

.rie-side-sentence {
  font-family: 'Playfair Display', serif;
  font-size: 1.05rem;
  font-style: italic;
  color: #0F172A;
}

.rie-ex-arrow {
  color: #94A3B8;
  font-size: 1.2rem;
}

.rie-intro-cta-box {
  display: flex;
  justify-content: center;
}

.rie-btn-hero {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: linear-gradient(135deg, #1E3A8A 0%, #0F172A 100%);
  color: #FFFFFF;
  border: none;
  padding: 15px 36px;
  border-radius: 40px;
  font-family: 'Manrope', sans-serif;
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  cursor: pointer;
  box-shadow: 0 8px 24px rgba(30, 58, 138, 0.25);
  transition: all 0.22s ease;
}

.rie-btn-hero:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 30px rgba(30, 58, 138, 0.35);
}

/* ── 05. CATEGORY SLIDES (SCREENS 1 TO 7) ── */
.rie-slide-category {
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

.rie-cat-header-strip {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.rie-cat-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: #EFF6FF;
  border: 1px solid #BFDBFE;
  color: #1E3A8A;
  font-size: 0.74rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 4px 12px;
  border-radius: 20px;
}

.rie-cat-nav-indicator {
  font-size: 0.8rem;
  color: #94A3B8;
  font-weight: 600;
}

.rie-category-heading {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: clamp(2rem, 3.5vw, 2.7rem);
  font-weight: 700;
  color: #0F172A;
  line-height: 1.2;
  margin: 0 0 20px;
}

.rie-category-guidance-card {
  background: #F8FAFC;
  border-left: 4px solid #1E3A8A;
  border-top: 1px solid #E2E8F0;
  border-right: 1px solid #E2E8F0;
  border-bottom: 1px solid #E2E8F0;
  border-radius: 12px;
  padding: 18px 22px;
  margin-bottom: 30px;
}

.rie-guidance-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #1E3A8A;
  margin-bottom: 6px;
}

.rie-guidance-text {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 1.15rem;
  line-height: 1.6;
  color: #1E293B;
  margin: 0;
  font-style: italic;
}

/* Pair Comparisons */
.rie-pairs-container {
  display: flex;
  flex-direction: column;
  gap: 18px;
  margin-bottom: 26px;
}

.rie-pairs-header-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #94A3B8;
  padding: 0 10px;
}

.rie-comparison-row {
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 16px;
  padding: 20px;
  box-shadow: 0 4px 18px rgba(15, 23, 42, 0.03);
}

.rie-row-context {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
}

.rie-context-dot {
  background: #1E3A8A;
  color: #FFFFFF;
  font-size: 0.7rem;
  font-weight: 800;
  padding: 2px 7px;
  border-radius: 6px;
}

.rie-context-label {
  font-size: 0.8rem;
  font-weight: 700;
  color: #64748B;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.rie-row-cards-split {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 16px;
}

.rie-pair-card {
  border-radius: 12px;
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.rie-card-informal {
  background: #FFF5F5;
  border: 1px solid #FED7D7;
}

.rie-card-formal {
  background: #F0F7FF;
  border: 1px solid #BAE6FD;
}

.rie-card-top-tag {
  display: flex;
  align-items: center;
}

.rie-card-informal .rie-tag-label {
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #C53030;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.rie-card-formal .rie-tag-label {
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #0369A1;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.rie-card-sentence {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 1.15rem;
  line-height: 1.5;
  color: #0F172A;
  font-weight: 600;
}

.rie-pair-connector {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  color: #94A3B8;
}

.rie-conn-line {
  width: 2px;
  height: 12px;
  background: #E2E8F0;
}

.rie-conn-arrow {
  font-size: 1.1rem;
  color: #64748B;
}

.rie-category-footnote {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.84rem;
  color: #64748B;
  background: #F8FAFC;
  padding: 12px 18px;
  border-radius: 10px;
  border: 1px solid #E2E8F0;
}

/* ── 06. SUMMARY SLIDE (SCREEN 8) ── */
.rie-slide-summary {
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

.rie-summary-prose-card {
  background: #F8FAFC;
  border: 1px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px 28px;
  margin-bottom: 24px;
}

.rie-sum-paragraph {
  font-size: 1.05rem;
  line-height: 1.7;
  color: #1E293B;
  margin: 0 0 12px;
}

.rie-sum-paragraph:last-child {
  margin-bottom: 0;
}

.rie-summary-categories-map {
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 16px;
  padding: 22px 26px;
  margin-bottom: 24px;
}

.rie-map-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: 'Manrope', sans-serif;
  font-size: 0.85rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #1E3A8A;
  margin-bottom: 16px;
}

.rie-map-chips-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 10px;
}

.rie-map-chip {
  background: #F1F5F9;
  border: 1px solid #CBD5E1;
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 0.88rem;
  color: #334155;
  font-weight: 500;
}

.rie-map-chip strong {
  color: #1E3A8A;
}

.rie-summary-golden-box {
  background: #FFFBEB;
  border-left: 4px solid #D97706;
  border-top: 1px solid #FDE68A;
  border-right: 1px solid #FDE68A;
  border-bottom: 1px solid #FDE68A;
  border-radius: 14px;
  padding: 22px 26px;
}

.rie-golden-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.74rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #B45309;
  margin-bottom: 8px;
}

.rie-golden-quote {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 1.25rem;
  line-height: 1.6;
  color: #78350F;
  margin: 0;
  font-style: italic;
  font-weight: 600;
}

/* ── 07. CLOSING SLIDE (SCREEN 9) ── */
.rie-slide-closing {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 30px 10px;
}

.rie-closing-crown {
  width: 68px;
  height: 68px;
  border-radius: 50%;
  background: #EFF6FF;
  border: 1px solid #BFDBFE;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: #1E3A8A;
  margin-bottom: 24px;
  box-shadow: 0 6px 20px rgba(30, 58, 138, 0.1);
}

.rie-closing-title {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: clamp(2.4rem, 4.5vw, 3.4rem);
  font-weight: 700;
  color: #0F172A;
  margin: 0 0 12px;
  letter-spacing: -0.02em;
}

.rie-closing-subtitle {
  font-size: 1.1rem;
  color: #64748B;
  margin: 0 0 32px;
}

.rie-closing-card {
  background: #F8FAFC;
  border: 1px solid #E2E8F0;
  border-radius: 18px;
  padding: 28px 36px;
  max-width: 680px;
  margin-bottom: 38px;
  box-shadow: 0 6px 24px rgba(15, 23, 42, 0.03);
}

.rie-closing-takeaway {
  font-family: 'Playfair Display', serif;
  font-size: 1.25rem;
  font-style: italic;
  color: #1E293B;
  line-height: 1.6;
  margin: 0 0 16px;
}

.rie-closing-meta {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 10px;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #94A3B8;
}

.rie-closing-actions-row {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
}

.rie-btn-final {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 30px;
  font-family: 'Manrope', sans-serif;
  font-size: 0.92rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: all 0.2s ease;
}

.rie-btn-final-primary {
  background: linear-gradient(135deg, #1E3A8A 0%, #0F172A 100%);
  color: #FFFFFF;
  border: none;
  box-shadow: 0 6px 20px rgba(30, 58, 138, 0.2);
}

.rie-btn-final-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 26px rgba(30, 58, 138, 0.3);
}

.rie-btn-final-secondary {
  background: #FFFFFF;
  color: #334155;
  border: 1px solid #CBD5E1;
}

.rie-btn-final-secondary:hover {
  background: #F1F5F9;
  border-color: #94A3B8;
  transform: translateY(-2px);
}

/* ── 08. BOTTOM NAVIGATION ACTIONS ── */
.rie-bottom-nav {
  margin-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 20px;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(226, 232, 240, 0.8);
  border-radius: 16px;
  box-shadow: 0 4px 18px rgba(15, 23, 42, 0.03);
}

.rie-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: 30px;
  font-family: 'Manrope', sans-serif;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: all 0.2s ease;
}

.rie-nav-btn-prev {
  background: #FFFFFF;
  color: #334155;
  border: 1px solid #CBD5E1;
}

.rie-nav-btn-prev:hover {
  background: #F1F5F9;
  border-color: #94A3B8;
  transform: translateX(-2px);
}

.rie-nav-btn-primary {
  background: linear-gradient(135deg, #1E3A8A 0%, #0F172A 100%);
  color: #FFFFFF;
  border: none;
  box-shadow: 0 4px 14px rgba(30, 58, 138, 0.2);
}

.rie-nav-btn-primary:hover {
  background: linear-gradient(135deg, #2563EB 0%, #1E3A8A 100%);
  transform: translateX(2px);
  box-shadow: 0 6px 20px rgba(30, 58, 138, 0.3);
}

.rie-nav-btn-secondary {
  background: #EFF6FF;
  color: #1E3A8A;
  border: 1px solid #BFDBFE;
}

.rie-nav-btn-secondary:hover {
  background: #DBEAFE;
}

.rie-nav-hint {
  font-size: 0.8rem;
  color: #94A3B8;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.rie-slide-dots {
  display: flex;
  align-items: center;
  gap: 8px;
}

.rie-dot-btn {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #CBD5E1;
  border: none;
  cursor: pointer;
  padding: 0;
  transition: all 0.22s ease;
}

.rie-dot-btn.active {
  width: 28px;
  border-radius: 10px;
  background: #1E3A8A;
  box-shadow: 0 2px 8px rgba(30, 58, 138, 0.35);
}

.rie-dot-btn:hover:not(.active) {
  background: #94A3B8;
}

/* ── 09. RESPONSIVE DESIGN & ACCESSIBILITY ── */
@media (max-width: 900px) {
  .rie-screen-viewport {
    padding: 32px 24px;
    min-height: auto;
  }
  .rie-row-cards-split {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .rie-pair-connector {
    transform: rotate(90deg);
    margin: 4px 0;
  }
  .rie-char-grid {
    grid-template-columns: 1fr;
  }
  .rie-intro-ex-duo {
    flex-direction: column;
  }
  .rie-ex-arrow {
    transform: rotate(90deg);
  }
}

@media (max-width: 640px) {
  .rie-pres-wrapper {
    padding: 16px 10px 60px;
  }
  .rie-top-bar {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding: 10px 14px;
  }
  .rie-screen-viewport {
    padding: 24px 16px;
  }
  .rie-bottom-nav {
    flex-direction: column;
    gap: 14px;
  }
  .rie-nav-btn {
    width: 100%;
    justify-content: center;
  }
  .rie-slide-dots {
    order: -1;
  }
}

/* Reduced Motion Mode */
@media (prefers-reduced-motion: reduce) {
  .rie-pres-ambient-glow {
    animation: none !important;
  }
  .animate-fade-in {
    animation: none !important;
  }
}