/* Geist Font */
@font-face {
  font-family: 'Geist';
  src: url('/css/geist/Geist-Regular.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Geist';
  src: url('/css/geist/Geist-Medium.woff2') format('woff2');
  font-weight: 500;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Geist';
  src: url('/css/geist/Geist-SemiBold.woff2') format('woff2');
  font-weight: 600;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Geist';
  src: url('/css/geist/Geist-Bold.woff2') format('woff2');
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

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

/* ---- Login Form ---- */
.login-container {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: #ffffff;
  font-family: 'Geist', -apple-system, BlinkMacSystemFont, sans-serif;
}

.login-box {
  text-align: center;
  max-width: 340px;
  width: 100%;
  padding: 0 24px;
}

.login-box h1 {
  font-size: 20px;
  font-weight: 700;
  color: #111827;
  margin-bottom: 6px;
  letter-spacing: -0.02em;
}

.login-box p {
  font-size: 14px;
  color: #6b7280;
  margin-bottom: 28px;
}

.login-box input[type="password"] {
  width: 100%;
  padding: 10px 14px;
  font-size: 15px;
  font-family: 'Geist', sans-serif;
  background: #ffffff;
  color: #111827;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  outline: none;
  transition: border-color 0.15s;
  box-sizing: border-box;
}

.login-box input[type="password"]:focus {
  border-color: #f97316;
}

.login-box input[type="password"]::placeholder {
  color: #9ca3af;
}

.login-box button {
  width: 100%;
  margin-top: 10px;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 600;
  font-family: 'Geist', sans-serif;
  color: #ffffff;
  background: #f97316;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s;
  letter-spacing: -0.01em;
}

.login-box button:hover {
  background: #ea580c;
}

.login-box .error {
  color: #ef4444;
  font-size: 13px;
  margin-top: 12px;
  display: none;
}

/* ---- Landing Page ---- */
.landing {
  min-height: 100vh;
  background: #ffffff;
  background-image:
    linear-gradient(to right, rgba(0, 0, 0, 0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0, 0, 0, 0.04) 1px, transparent 1px);
  background-size: 32px 32px;
  font-family: 'Geist', -apple-system, BlinkMacSystemFont, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  padding: 80px 24px 60px;
  position: relative;
}

.landing::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at center, transparent 40%, #ffffff 75%);
  pointer-events: none;
}

.landing-header,
.deck-grid,
.resources-section {
  position: relative;
  z-index: 1;
}

.landing-header {
  text-align: center;
  margin-bottom: 32px;
}

.landing-pill {
  display: inline-block;
  background: #fff7ed;
  color: #ea580c;
  font-weight: 600;
  font-size: 12px;
  padding: 6px 18px;
  border-radius: 100px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 24px;
  border: 1px solid #fed7aa;
}

.landing-header h1 {
  font-size: 48px;
  font-weight: 700;
  color: #111827;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin: 0 0 16px 0;
}

.landing-header p {
  font-size: 18px;
  color: #6b7280;
  font-weight: 400;
  margin: 0;
}

.deck-grid {
  display: flex;
  gap: 24px;
  max-width: 1100px;
  width: 100%;
}

.deck-card {
  flex: 1;
  background: linear-gradient(135deg, #ffffff 0%, #fff7ed 100%);
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  padding: 24px 24px;
  text-decoration: none;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
  display: flex;
  flex-direction: column;
}

.deck-card:hover {
  border-color: #f97316;
  box-shadow: 0 4px 24px rgba(249, 115, 22, 0.1);
  transform: translateY(-4px);
}

.deck-number {
  font-size: 13px;
  font-weight: 700;
  color: #f97316;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.deck-card h2 {
  font-size: 22px;
  font-weight: 700;
  color: #111827;
  letter-spacing: -0.02em;
  margin: 0 0 8px 0;
  line-height: 1.2;
}

.deck-card .deck-meta {
  font-size: 13px;
  color: #9ca3af;
  margin-bottom: 16px;
}

.deck-card .deck-desc {
  font-size: 14px;
  color: #6b7280;
  line-height: 1.5;
  flex: 1;
}

.deck-card .deck-topics {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 20px;
}

.deck-card .deck-topic {
  font-size: 11px;
  font-weight: 600;
  color: #6b7280;
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  padding: 4px 10px;
  border-radius: 4px;
}

/* ---- Resources Section ---- */
.resources-section {
  margin-top: 40px;
  max-width: 1100px;
  width: 100%;
}

.resources-label {
  font-size: 11px;
  font-weight: 700;
  color: #9ca3af;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 16px;
  padding-left: 4px;
}

.resources-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-auto-flow: column;
  grid-template-rows: 1fr 1fr 1fr;
  gap: 8px;
}

.resource-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  background: #ffffff;
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  text-decoration: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.resource-item:hover {
  border-color: #f97316;
  box-shadow: 0 2px 12px rgba(249, 115, 22, 0.08);
}

.resource-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  color: #6b7280;
  flex-shrink: 0;
}

.resource-item:hover .resource-icon {
  color: #f97316;
  border-color: #fed7aa;
  background: #fff7ed;
}

.resource-text {
  flex: 1;
  min-width: 0;
}

.resource-name {
  font-size: 14px;
  font-weight: 600;
  color: #111827;
  letter-spacing: -0.01em;
}

.resource-url {
  font-size: 12px;
  color: #9ca3af;
  margin-top: 1px;
}

.resource-badge {
  font-size: 10px;
  font-weight: 600;
  color: #9ca3af;
  background: #f3f4f6;
  border: 1px solid #e5e7eb;
  padding: 3px 10px;
  border-radius: 100px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  flex-shrink: 0;
}

.resource-code {
  font-size: 12px;
  font-weight: 600;
  font-family: 'SF Mono', 'Fira Code', monospace;
  color: #ea580c;
  background: #fff7ed;
  border: 1px solid #fed7aa;
  padding: 4px 12px;
  border-radius: 6px;
  flex-shrink: 0;
}

.resource-arrow {
  color: #d1d5db;
  flex-shrink: 0;
  transition: color 0.2s;
}

.resource-item:hover .resource-arrow {
  color: #f97316;
}

.landing-footer {
  position: fixed;
  top: 14px;
  right: 20px;
  font-size: 10px;
  color: #d1d5db;
  z-index: 100;
  letter-spacing: 0.04em;
}

.landing-footer a {
  color: #d1d5db;
  text-decoration: none;
}

.landing-footer a:hover {
  color: #9ca3af;
}

/* ---- Pillar Navigation Bar ---- */
#pillar-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 40px;
  background: #ffffff;
  border-bottom: 1px solid #f0f0f0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2px;
  z-index: 200;
  padding: 0 60px;
  font-family: 'Geist', sans-serif;
}

#pillar-nav .pillar-link {
  font-size: 11px;
  font-weight: 500;
  color: #a3a3a3;
  text-decoration: none;
  padding: 6px 12px;
  border-radius: 4px;
  cursor: pointer;
  transition: color 0.15s, background 0.15s;
  white-space: nowrap;
  letter-spacing: -0.01em;
}

#pillar-nav .pillar-link:hover {
  color: #404040;
  background: #f5f5f5;
}

#pillar-nav .pillar-link.active {
  color: #ea580c;
  background: #fff7ed;
  font-weight: 600;
}

#pillar-nav .nav-back {
  position: absolute;
  left: 16px;
  font-size: 12px;
  font-weight: 500;
  color: #a3a3a3;
  text-decoration: none;
  transition: color 0.15s;
}

#pillar-nav .nav-back:hover {
  color: #f97316;
}

/* ---- Reveal.js Theme ---- */
.reveal-viewport {
  background: #ffffff;
}

.reveal {
  font-family: 'Geist', -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 28px;
  font-weight: 400;
  color: #171717;
  -webkit-font-smoothing: antialiased;
}

/* Offset slides for pillar nav */
.reveal .slides {
  margin-top: 10px;
}

.reveal h1, .reveal h2, .reveal h3, .reveal h4 {
  font-family: 'Geist', -apple-system, BlinkMacSystemFont, sans-serif;
  font-weight: 700;
  color: #000000;
  text-transform: none;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 0.4em;
}

.reveal h1 {
  font-size: 2.4em;
}

.reveal h2 {
  font-size: 1.8em;
}

.reveal h3 {
  font-size: 1em;
  font-weight: 600;
  color: #525252;
  letter-spacing: -0.02em;
}

.reveal p {
  line-height: 1.4;
  margin-bottom: 0.4em;
  color: #404040;
  max-width: 960px;
  margin-left: auto;
  margin-right: auto;
}

.reveal ul, .reveal ol {
  display: inline-block;
  margin-left: 0;
  text-align: left;
  list-style: none;
  padding: 0;
  max-width: 960px;
}

.reveal li {
  margin-bottom: 0.5em;
  line-height: 1.4;
  color: #404040;
  padding-left: 1.6em;
  position: relative;
}

.reveal li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.45em;
  width: 6px;
  height: 6px;
  background: #f97316;
  border-radius: 2px;
}

.reveal ol {
  counter-reset: list-counter;
}

.reveal ol li {
  counter-increment: list-counter;
}

.reveal ol li::before {
  content: counter(list-counter);
  background: #f97316;
  color: #ffffff;
  width: 24px;
  height: 24px;
  font-size: 14px;
  font-weight: 700;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  top: 7px;
  left: 0;
}

.reveal strong {
  font-weight: 700;
  color: #000000;
}

.reveal em {
  color: #737373;
  font-style: italic;
}

.reveal a {
  color: #000000;
  text-decoration: underline;
  text-decoration-color: #f97316;
  text-underline-offset: 3px;
  text-decoration-thickness: 2px;
}

.reveal .slide-number a {
  text-decoration: none;
}

.reveal blockquote {
  background: transparent;
  border-left: 4px solid #f97316;
  padding: 8px 16px;
  margin: 16px auto;
  font-style: normal;
  font-size: 0.75em;
  font-weight: 500;
  color: #737373;
  width: auto;
  max-width: 700px;
  box-sizing: border-box;
  text-align: left;
}

.reveal code {
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 0.8em;
  background: #f5f5f5;
  padding: 2px 6px;
  border-radius: 3px;
  color: #000000;
}

.reveal pre {
  width: 90%;
  max-width: 960px;
  margin: 12px auto;
  font-size: 0.55em;
}

.reveal pre code {
  padding: 14px 18px;
  line-height: 1.5;
  background: #0a0a0a;
  color: #e5e5e5;
  border-radius: 8px;
  display: block;
  overflow-x: auto;
}

/* ---- Section numbers ---- */
.reveal .section-number {
  font-size: 0.5em;
  font-weight: 700;
  color: #f97316;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 0.2em;
  display: block;
}

/* ---- Orange accent bar for section titles ---- */
.reveal hr {
  border: none;
  height: 3px;
  background: #f97316;
  width: 50px;
  margin: 0 auto 0.8em auto;
}

/* ---- Tables ---- */
.reveal table {
  border-collapse: collapse;
  width: auto;
  max-width: 95%;
  margin: 10px auto;
  font-size: 0.55em;
}

.reveal table th {
  background: #18181b;
  color: #ffffff;
  font-weight: 600;
  padding: 7px 12px;
  text-align: left;
  letter-spacing: -0.01em;
}

.reveal table td {
  padding: 5px 12px;
  border-bottom: 1px solid #e5e5e5;
  text-align: left;
  color: #404040;
}

.reveal table tr:nth-child(even) td {
  background: #fafafa;
}

/* ---- Images & SVGs ---- */
.reveal img, .reveal svg {
  max-width: 95%;
  max-height: 65vh;
  margin: 10px auto;
  display: block;
  border: none;
  box-shadow: none;
}

/* ---- Controls ---- */
.reveal .controls {
  color: #d4d4d4;
}

/* ---- Progress bar ---- */
.reveal .progress {
  color: #f97316;
  height: 4px;
}

/* ---- Footer Branding ---- */
#apek-footer {
  position: fixed;
  bottom: 14px;
  right: 20px;
  font-family: 'Geist', sans-serif;
  font-size: 10px;
  color: #d4d4d4;
  z-index: 100;
  letter-spacing: 0.04em;
}

#apek-footer a {
  color: #d4d4d4;
  text-decoration: none;
}

#apek-footer a:hover {
  color: #a3a3a3;
}

/* ---- Slide spacing ---- */
.reveal section {
  padding: 10px 0;
}

/* ---- Keyword pill ---- */
.reveal .pill {
  display: inline-block;
  background: #f97316;
  color: #ffffff;
  font-weight: 700;
  font-size: 0.55em;
  padding: 3px 10px;
  border-radius: 4px;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  margin-right: 4px;
}

/* ---- Large stat number ---- */
.reveal .stat {
  font-size: 2.6em;
  font-weight: 700;
  color: #000000;
  letter-spacing: -0.04em;
  line-height: 1;
}

.reveal .stat-label {
  font-size: 0.7em;
  color: #737373;
  font-weight: 400;
}

/* ---- Hero title slide (white) ---- */
.reveal .hero {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
}

.reveal .hero h1 {
  font-size: 2.8em;
  font-weight: 700;
  color: #000000;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 0.3em;
  text-wrap: balance;
}

.reveal .hero-pill {
  display: inline-block;
  background: #fff7ed;
  color: #ea580c;
  font-weight: 600;
  font-size: 0.45em;
  padding: 6px 18px;
  border-radius: 100px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 1.5em;
  border: 1px solid #fed7aa;
}

.reveal .hero-sub {
  font-size: 0.65em;
  color: #737373;
  font-weight: 400;
  line-height: 1.5;
  max-width: 700px;
  text-wrap: balance;
}

/* Hero with photo background - white text */
.reveal .hero-photo h1 {
  color: #ffffff;
  text-shadow: 0 2px 20px rgba(0,0,0,0.5);
}

.reveal .hero-photo .hero-pill {
  background: rgba(255,255,255,0.2);
  color: #ffffff;
  border-color: rgba(255,255,255,0.3);
  backdrop-filter: blur(4px);
}

.reveal .hero-photo .hero-sub {
  color: rgba(255,255,255,0.85);
  text-shadow: 0 1px 10px rgba(0,0,0,0.4);
}

/* ---- Two-column layout ---- */
.reveal .columns {
  display: flex;
  gap: 32px;
  align-items: flex-start;
  text-align: left;
  max-width: 1100px;
  margin: 0 auto;
}

.reveal .columns .col {
  flex: 1;
  min-width: 0;
}

.reveal .columns .col-narrow {
  flex: 0 0 40%;
}

.reveal .columns .col-wide {
  flex: 0 0 58%;
}

/* ---- Three-column layout ---- */
.reveal .cols-3 {
  display: flex;
  gap: 28px;
  text-align: left;
  max-width: 1100px;
  margin: 32px auto 0;
}

.reveal .cols-3 > div {
  flex: 1;
  min-width: 0;
}

/* ---- 2×2 grid layout ---- */
.reveal .grid-2x2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  max-width: 960px;
  margin: 24px auto 0;
}

.reveal .grid-2x2 > .card {
  margin-bottom: 0;
}

/* ---- Card / box ---- */
.reveal .card {
  background: #fafafa;
  border: 1px solid #e5e5e5;
  border-top: 3px solid #f97316;
  border-radius: 8px;
  padding: 28px 24px;
  margin-bottom: 12px;
  text-align: left;
}

.reveal .card h4 {
  font-size: 0.9em;
  font-weight: 700;
  margin-bottom: 0.4em;
  color: #f97316;
}

.reveal .card p, .reveal .card li {
  font-size: 0.75em;
  margin-bottom: 0.3em;
  line-height: 1.4;
}

/* ---- Image card ---- */
.reveal .image-card {
  background: #fafafa;
  border: 1px solid #e5e5e5;
  border-radius: 10px;
  overflow: hidden;
  text-align: left;
}

.reveal .image-card .image-card-img {
  width: 100%;
  height: 140px;
  background-size: cover;
  background-position: center;
}

.reveal .image-card .image-card-body {
  padding: 20px 22px;
}

.reveal .image-card .image-card-body h4 {
  font-size: 0.9em;
  font-weight: 700;
  margin-bottom: 0.3em;
  color: #f97316;
}

.reveal .image-card .image-card-body p {
  font-size: 0.7em;
  margin-bottom: 0.25em;
  line-height: 1.4;
}

/* ---- Diagram container (ASCII art) ---- */
.reveal .diagram {
  background: #0a0a0a;
  color: #a3e635;
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 0.48em;
  line-height: 1.4;
  padding: 18px 24px;
  border-radius: 8px;
  text-align: left;
  white-space: pre;
  overflow-x: auto;
  max-width: 95%;
  margin: 10px auto;
}

/* ---- Flow / pipeline steps ---- */
.reveal .flow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  margin: 16px auto;
  flex-wrap: wrap;
}

.reveal .flow-step {
  background: #f5f5f5;
  border: 1px solid #e5e5e5;
  border-radius: 6px;
  padding: 8px 14px;
  font-size: 0.7em;
  font-weight: 600;
  color: #18181b;
  text-align: center;
}

.reveal .flow-arrow {
  font-size: 0.8em;
  color: #f97316;
  padding: 0 8px;
  font-weight: 700;
}

/* ---- Accent box / callout ---- */
.reveal .callout {
  background: #fff7ed;
  border-left: 4px solid #f97316;
  padding: 10px 16px;
  margin: 12px auto;
  max-width: 800px;
  text-align: left;
  border-radius: 0 6px 6px 0;
}

.reveal .callout p {
  font-size: 0.8em;
  margin: 0;
  color: #78350f;
}

/* ---- Badge grid ---- */
.reveal .badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin: 12px auto;
}

.reveal .badge {
  background: #f5f5f5;
  border: 1px solid #e5e5e5;
  border-radius: 6px;
  padding: 6px 14px;
  font-size: 0.65em;
  font-weight: 600;
  color: #18181b;
}

.reveal .badge-orange {
  background: #fff7ed;
  border-color: #fed7aa;
  color: #c2410c;
}

/* ---- Badge grid (fixed 4-col) ---- */
.reveal .badge-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  max-width: 880px;
  margin: 16px auto;
}

.reveal .badge-grid .badge {
  text-align: center;
  padding: 10px 8px;
}

/* ---- Big quote / story slide ---- */
.reveal .story {
  max-width: 820px;
  margin: 0 auto;
  text-align: left;
}

.reveal .story p {
  font-size: 1em;
  line-height: 1.6;
  color: #404040;
}

.reveal .story .highlight {
  color: #f97316;
  font-weight: 600;
}

/* ---- Story slide with side image ---- */
.reveal .story-with-image {
  display: flex;
  align-items: center;
  gap: 48px;
  max-width: 1050px;
  margin: 0 auto;
  text-align: left;
}

.reveal .story-with-image .story-text {
  flex: 1;
  min-width: 0;
}

.reveal .story-with-image .story-text p {
  font-size: 0.95em;
  line-height: 1.6;
  color: #404040;
  margin: 0;
}

.reveal .story-with-image .story-img {
  flex: 0 0 320px;
  max-width: 320px;
}

.reveal .story-with-image .story-img img {
  width: 100%;
  height: auto;
  border-radius: 12px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.1);
  margin: 0;
}

/* ---- Impact slide with background image ---- */
.reveal .impact-with-image {
  text-align: center;
  max-width: 900px;
  margin: 0 auto;
  position: relative;
}

.reveal .impact-with-image .impact-bg {
  width: 280px;
  height: auto;
  border-radius: 16px;
  opacity: 0.15;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 0;
  filter: blur(2px);
  margin: 0;
}

.reveal .impact-with-image .impact-content {
  position: relative;
  z-index: 1;
}

.reveal .impact-with-image .impact-content p {
  font-size: 1.1em;
  line-height: 1.5;
}

/* ---- Centered impact text ---- */
.reveal .impact {
  text-align: center;
  max-width: 900px;
  margin: 0 auto;
}

.reveal .impact h2 {
  font-size: 2em;
  margin-bottom: 0.6em;
}

.reveal .impact p {
  font-size: 1.1em;
  line-height: 1.5;
}

/* ---- Highlight line (big inline focus text) ---- */
.reveal .highlight-line {
  display: inline-block;
  font-size: 1.3em;
  font-weight: 700;
  color: #000000;
  background: #fff7ed;
  border-bottom: 3px solid #f97316;
  padding: 6px 18px;
  margin-top: 0.4em;
  letter-spacing: -0.02em;
}

/* ---- Section intro slide ---- */
.reveal .section-intro {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 50vh;
}

.reveal .section-intro h2 {
  font-size: 2.6em;
  margin-bottom: 0.2em;
}

.reveal .section-intro p {
  font-size: 0.85em;
  color: #737373;
}

/* ---- Icon card with emoji ---- */
.reveal .icon-card {
  text-align: center;
  padding: 20px;
}

.reveal .icon-card .icon {
  font-size: 2em;
  margin-bottom: 8px;
}

/* ---- Formula / equation styling ---- */
.reveal .formula {
  font-size: 1.4em;
  font-weight: 700;
  color: #000000;
  text-align: center;
  padding: 20px 0;
  letter-spacing: -0.02em;
}

.reveal .formula .operator {
  color: #f97316;
  padding: 0 8px;
}

/* ---- Table of Contents ---- */
.reveal .toc {
  text-align: left;
  max-width: 1050px;
  margin: 0 auto;
}

.reveal .toc-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 20px;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.reveal .toc-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 20px;
  background: #fafafa;
  border: 1px solid #e5e5e5;
  border-radius: 10px;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
  text-decoration: none;
}

.reveal .toc-item:hover {
  border-color: #f97316;
  background: #fff7ed;
}

.reveal .toc-num {
  font-size: 0.5em;
  font-weight: 700;
  color: #ffffff;
  background: #f97316;
  min-width: 28px;
  height: 28px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.reveal .toc-text {
  flex: 1;
  text-align: left;
  min-width: 0;
}

.reveal .toc-label {
  font-size: 0.6em;
  font-weight: 700;
  color: #18181b;
  letter-spacing: -0.01em;
}

.reveal .toc-desc {
  font-size: 0.48em;
  color: #737373;
  font-weight: 400;
  margin-top: 2px;
}

.reveal .toc-slides {
  font-size: 0.45em;
  color: #a3a3a3;
  font-weight: 500;
  flex-shrink: 0;
  white-space: nowrap;
}

/* ---- Back link ---- */
.back-link {
  position: fixed;
  top: 14px;
  left: 20px;
  font-family: 'Geist', sans-serif;
  font-size: 12px;
  font-weight: 500;
  color: #a3a3a3;
  text-decoration: none;
  z-index: 100;
  letter-spacing: 0.01em;
  transition: color 0.15s;
}

.back-link:hover {
  color: #f97316;
}

/* ---- Spacing utilities (Tailwind-style, scoped for specificity) ---- */
.reveal .mt-1 { margin-top: 4px !important; }
.reveal .mt-2 { margin-top: 8px !important; }
.reveal .mt-3 { margin-top: 12px !important; }
.reveal .mt-4 { margin-top: 16px !important; }
.reveal .mt-5 { margin-top: 20px !important; }
.reveal .mt-6 { margin-top: 24px !important; }
.reveal .mt-8 { margin-top: 32px !important; }
.reveal .mt-10 { margin-top: 40px !important; }
.reveal .mt-12 { margin-top: 48px !important; }
.reveal .mt-16 { margin-top: 64px !important; }

.reveal .mb-1 { margin-bottom: 4px !important; }
.reveal .mb-2 { margin-bottom: 8px !important; }
.reveal .mb-3 { margin-bottom: 12px !important; }
.reveal .mb-4 { margin-bottom: 16px !important; }
.reveal .mb-5 { margin-bottom: 20px !important; }
.reveal .mb-6 { margin-bottom: 24px !important; }
.reveal .mb-8 { margin-bottom: 32px !important; }
.reveal .mb-10 { margin-bottom: 40px !important; }
.reveal .mb-12 { margin-bottom: 48px !important; }
.reveal .mb-16 { margin-bottom: 64px !important; }

.reveal .my-2 { margin-top: 8px !important; margin-bottom: 8px !important; }
.reveal .my-4 { margin-top: 16px !important; margin-bottom: 16px !important; }
.reveal .my-6 { margin-top: 24px !important; margin-bottom: 24px !important; }
.reveal .my-8 { margin-top: 32px !important; margin-bottom: 32px !important; }
.reveal .my-10 { margin-top: 40px !important; margin-bottom: 40px !important; }
.reveal .my-12 { margin-top: 48px !important; margin-bottom: 48px !important; }

.reveal .pt-2 { padding-top: 8px !important; }
.reveal .pt-4 { padding-top: 16px !important; }
.reveal .pt-6 { padding-top: 24px !important; }
.reveal .pt-8 { padding-top: 32px !important; }

.reveal .pb-2 { padding-bottom: 8px !important; }
.reveal .pb-4 { padding-bottom: 16px !important; }
.reveal .pb-6 { padding-bottom: 24px !important; }
.reveal .pb-8 { padding-bottom: 32px !important; }

.reveal .py-2 { padding-top: 8px !important; padding-bottom: 8px !important; }
.reveal .py-4 { padding-top: 16px !important; padding-bottom: 16px !important; }
.reveal .py-6 { padding-top: 24px !important; padding-bottom: 24px !important; }
.reveal .py-8 { padding-top: 32px !important; padding-bottom: 32px !important; }

.reveal .px-4 { padding-left: 16px !important; padding-right: 16px !important; }
.reveal .px-6 { padding-left: 24px !important; padding-right: 24px !important; }
.reveal .px-8 { padding-left: 32px !important; padding-right: 32px !important; }

.reveal .gap-2 { gap: 8px !important; }
.reveal .gap-4 { gap: 16px !important; }
.reveal .gap-6 { gap: 24px !important; }
.reveal .gap-8 { gap: 32px !important; }

.reveal .text-center { text-align: center !important; }
.reveal .text-left { text-align: left !important; }

/* ---- Print styles ---- */
@media print {
  .reveal table th {
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }
}