:root {
  --ink: #050505;
  --muted: #545961;
  --line: #c8ccd2;
  --paper: #f1f2f4;
  --panel: #ffffff;
  --soft: #ededed;
  --blue: #3d8dff;
  --blue-dark: #1b63ce;
  --shadow: 0 18px 50px rgba(22, 30, 42, 0.12);
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

a {
  color: var(--blue-dark);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button:focus-visible,
a:focus-visible {
  outline: 3px solid rgba(61, 141, 255, 0.45);
  outline-offset: 3px;
}

.site-shell {
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.topbar {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 14px 28px;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.94);
}

.brand {
  display: grid;
  gap: 2px;
  color: var(--ink);
  text-decoration: none;
  line-height: 1.1;
}

.brand-kicker,
.index-label,
.slide-kicker {
  color: var(--blue);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.brand strong {
  font-size: 18px;
}

.top-links {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 18px;
  font-size: 14px;
  font-weight: 700;
}

.top-links a {
  color: var(--ink);
  text-decoration: none;
}

.top-links a:hover {
  color: var(--blue-dark);
}

.download-link {
  padding: 10px 13px;
  border: 1px solid var(--ink);
}

.deck-workspace {
  min-width: 0;
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: 26px;
  padding: 26px 28px 20px;
}

.slide-index {
  min-width: 0;
  align-self: start;
  position: sticky;
  top: 20px;
  max-height: calc(100vh - 138px);
  overflow: auto;
  padding-right: 12px;
}

.index-label {
  margin: 0 0 12px;
}

.slide-index ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
}

.slide-index button {
  width: 100%;
  display: grid;
  grid-template-columns: 26px 1fr;
  gap: 8px;
  align-items: start;
  padding: 9px 8px;
  border: 0;
  border-left: 2px solid transparent;
  background: transparent;
  color: var(--muted);
  text-align: left;
  cursor: pointer;
  font: inherit;
  font-size: 13px;
  line-height: 1.25;
}

.slide-index button:hover {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.65);
}

.slide-index button.active {
  border-left-color: var(--blue);
  color: var(--ink);
  background: var(--panel);
  font-weight: 700;
}

.slide-number {
  color: var(--blue);
  font-variant-numeric: tabular-nums;
}

.stage-column {
  min-width: 0;
  display: grid;
  align-content: start;
  gap: 14px;
}

.slide-stage {
  width: 100%;
  aspect-ratio: 16 / 9;
  min-height: 540px;
  position: relative;
  overflow: auto;
  padding: clamp(30px, 4vw, 62px);
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.slide-stage h1 {
  max-width: 1120px;
  margin: 0;
  font-size: clamp(38px, 4.2vw, 68px);
  line-height: 0.98;
  letter-spacing: -0.04em;
}

.slide-stage h2 {
  margin: 0;
  font-size: clamp(34px, 3.4vw, 54px);
  line-height: 1.02;
  letter-spacing: -0.035em;
}

.slide-stage h3 {
  margin: 0;
  font-size: clamp(22px, 2vw, 32px);
  line-height: 1.1;
}

.slide-stage p {
  font-size: clamp(18px, 1.55vw, 25px);
  line-height: 1.35;
}

.slide-stage .small {
  font-size: clamp(15px, 1.15vw, 19px);
}

.slide-kicker {
  margin: 0 0 26px;
}

.cover-layout,
.message-layout {
  min-height: 100%;
  display: grid;
  align-content: end;
  gap: 18px;
}

.cover-meta {
  position: absolute;
  inset: 40px 44px auto;
  display: flex;
  justify-content: space-between;
  gap: 30px;
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.cover-subtitle {
  margin: 0;
  font-size: clamp(30px, 3.5vw, 56px) !important;
  line-height: 1 !important;
}

.message-layout {
  align-content: center;
  max-width: 1050px;
}

.message-layout h2 {
  font-size: clamp(46px, 6vw, 86px);
  line-height: 0.95;
}

.message-layout p:last-child {
  max-width: 720px;
}

.intro-copy {
  max-width: 1120px;
  margin: 20px 0 0;
}

.three-grid,
.four-grid,
.two-grid,
.metric-grid,
.link-grid {
  display: grid;
  gap: clamp(22px, 3vw, 48px);
}

.three-grid,
.metric-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.four-grid,
.link-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.two-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.lower-grid {
  margin-top: clamp(80px, 12vh, 165px);
}

.mid-grid {
  margin-top: clamp(50px, 8vh, 100px);
}

.text-column p,
.link-block p {
  margin: 12px 0 0;
}

.soft-panel {
  min-height: 210px;
  display: grid;
  align-content: end;
  gap: 18px;
  padding: 30px;
  background: var(--soft);
}

.soft-panel p {
  margin: 0;
}

.compare-card {
  display: grid;
  gap: 20px;
}

.compare-heading {
  min-height: 110px;
  display: flex;
  align-items: center;
  padding: 26px 30px;
  background: var(--soft);
}

.compare-card ul,
.decision-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
  font-size: clamp(17px, 1.35vw, 22px);
  line-height: 1.3;
}

.timeline {
  margin-top: clamp(78px, 12vh, 150px);
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 48px;
}

.timeline::before {
  content: "";
  position: absolute;
  top: 33px;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--ink);
}

.timeline-step {
  position: relative;
  padding-top: 70px;
}

.timeline-step::before {
  content: "";
  position: absolute;
  top: 27px;
  left: 0;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--ink);
}

.timeline-label {
  position: absolute;
  top: 0;
  color: var(--blue);
  font-size: 15px;
  font-weight: 800;
  text-transform: uppercase;
}

.timeline-step p {
  margin: 12px 0 0;
}

.review-link {
  display: inline-block;
  margin-top: 18px;
  font-size: clamp(18px, 1.4vw, 22px);
}

.grader-table {
  width: 100%;
  margin-top: 26px;
  border-collapse: collapse;
  table-layout: fixed;
  font-size: clamp(12px, 1.05vw, 17px);
}

.grader-table th,
.grader-table td {
  padding: 9px 10px;
  border: 1px solid var(--ink);
  text-align: left;
  vertical-align: top;
}

.grader-table th {
  color: #fff;
  background: var(--ink);
}

.big-number {
  font-size: clamp(48px, 5vw, 76px);
  font-weight: 800;
  line-height: 1;
}

.link-grid {
  margin-top: clamp(70px, 11vh, 140px);
}

.link-block a {
  font-size: clamp(18px, 1.45vw, 23px);
}

.deck-controls {
  display: grid;
  grid-template-columns: auto minmax(220px, 1fr) auto;
  gap: 20px;
  align-items: center;
}

.control-group {
  display: flex;
  gap: 8px;
}

.deck-controls button {
  min-height: 42px;
  padding: 0 15px;
  border: 1px solid var(--ink);
  background: var(--panel);
  color: var(--ink);
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.deck-controls button:hover {
  color: #fff;
  background: var(--ink);
}

.progress-wrap {
  display: grid;
  grid-template-columns: 62px 1fr;
  gap: 12px;
  align-items: center;
  color: var(--muted);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
}

.progress-track {
  height: 4px;
  overflow: hidden;
  background: #d7d9dd;
}

#progress {
  display: block;
  height: 100%;
  background: var(--blue);
  transition: width 180ms ease;
}

.keyboard-hint {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.review-footer {
  min-height: 46px;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
  padding: 10px 28px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  background: var(--panel);
  font-size: 12px;
}

.review-footer a {
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
}

.review-footer a:hover {
  color: var(--blue-dark);
}

@media (max-width: 1100px) {
  .top-links a:not(.download-link) {
    display: none;
  }

  .deck-workspace {
    grid-template-columns: 190px minmax(0, 1fr);
    gap: 18px;
    padding-inline: 18px;
  }

  .slide-stage {
    min-height: 500px;
  }
}

@media (max-width: 780px) {
  .topbar {
    padding-inline: 16px;
  }

  .brand strong {
    font-size: 15px;
  }

  .deck-workspace {
    display: block;
    padding: 14px;
  }

  .slide-index {
    display: none;
  }

  .slide-stage {
    aspect-ratio: auto;
    min-height: calc(100vh - 205px);
    padding: 28px 24px;
  }

  .cover-meta {
    position: static;
    display: grid;
    margin-bottom: 120px;
  }

  .three-grid,
  .four-grid,
  .two-grid,
  .metric-grid,
  .link-grid,
  .timeline {
    grid-template-columns: 1fr;
  }

  .lower-grid,
  .mid-grid,
  .link-grid,
  .timeline {
    margin-top: 42px;
  }

  .timeline {
    gap: 34px;
  }

  .timeline::before {
    left: 6px;
    top: 0;
    bottom: 0;
    right: auto;
    width: 1px;
    height: auto;
  }

  .timeline-step {
    padding: 0 0 0 34px;
  }

  .timeline-step::before {
    top: 4px;
    left: 0;
  }

  .timeline-label {
    position: static;
  }

  .soft-panel {
    min-height: 160px;
  }

  .grader-table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
  }

  .deck-controls {
    grid-template-columns: 1fr auto;
  }

  .progress-wrap {
    grid-column: 1 / -1;
    grid-row: 2;
  }

  .keyboard-hint {
    display: none;
  }

  .review-footer {
    display: grid;
    padding-inline: 16px;
  }
}

@media print {
  .topbar,
  .slide-index,
  .deck-controls,
  .review-footer {
    display: none !important;
  }

  .deck-workspace {
    display: block;
    padding: 0;
  }

  .slide-stage {
    min-height: auto;
    border: 0;
    box-shadow: none;
  }
}