* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 155px; }
body { margin: 0; background: var(--bg); color: var(--fg); font: var(--type-body); -webkit-font-smoothing: antialiased; }
a { color: inherit; text-underline-offset: 4px; }
button { font: inherit; color: inherit; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--activity); outline-offset: 5px; }
::selection { background: color-mix(in srgb, var(--activity) 20%, var(--bg)); }
.wrap { width: min(1120px, calc(100% - 80px)); margin-inline: auto; }
.site-header { position: sticky; top: 0; z-index: 10; background: var(--bg); }
.top { min-height: 96px; }
.skip-link { position: fixed; top: -100px; left: 12px; padding: 12px; background: var(--bg); z-index: 30; }
.skip-link:focus { top: 12px; }
.hero { padding: 64px 0 40px; }
.eyebrow { color: var(--text-muted); font: var(--type-eyebrow); letter-spacing: var(--ls-eyebrow); text-transform: uppercase; margin: 0 0 20px; }
h1 { font: var(--type-hero); font-size: clamp(34px, 6vw, var(--fs-hero)); letter-spacing: var(--ls-hero); line-height: 1.08; margin: 0; }
h1 em { color: var(--activity); font-style: normal; }
.hero-bottom { display: flex; align-items: baseline; justify-content: space-between; gap: 24px; margin-top: 24px; }
.hero-bottom p { margin: 0; font: var(--type-prose); color: var(--text-note); }
.down-link { font: var(--type-meta); text-decoration: none; white-space: nowrap; }
.down-link span { margin-left: 14px; color: var(--activity); }
.chapter-nav { display: flex; gap: 34px; border-bottom: 1px solid var(--rule); background: var(--bg); position: sticky; top: 96px; z-index: 9; }
.chapter-nav a { text-decoration: none; padding: 18px 0; color: var(--text-muted); border-bottom: 2px solid transparent; }
.chapter-nav a span { font: 11px var(--font-mono); margin-right: 12px; }
.chapter-nav a[aria-current] { color: var(--fg); border-color: var(--activity); }
.chapter { padding-top: 46px; padding-bottom: 58px; scroll-margin-top: 0; }
.chapter-heading { display: flex; justify-content: space-between; align-items: flex-end; gap: 32px; margin-bottom: 28px; }
.chapter-heading .eyebrow { margin-bottom: 13px; }
h2 { font: var(--type-title); letter-spacing: var(--ls-title); margin: 0; line-height: 1.16; }
.chapter-heading > p { margin: 0 0 2px; color: var(--text-muted); font: var(--type-body); }
.scene { margin: 0; border: 1px solid var(--rule); border-radius: var(--r-card); overflow: hidden; background: var(--bg); }
.diagram-toolbar { display: flex; justify-content: space-between; align-items: center; gap: 14px; padding: 17px 22px 0; }
[hidden] { display: none !important; }
.focus-controls, .zoom-controls { display: inline-flex; align-items: center; gap: 4px; }
.diagram-toolbar button { background: transparent; border: 1px solid transparent; padding: 6px 12px; border-radius: var(--r-sm); color: var(--text-muted); font: var(--type-meta); cursor: pointer; min-height: 32px; }
.diagram-toolbar button:hover { color: var(--fg); border-color: var(--rule); }
.focus-controls button[aria-pressed="true"] { background: var(--surface); color: var(--fg); border-color: var(--rule); }
.zoom-controls button { min-width: 32px; padding-inline: 8px; }
.zoom-controls button[data-zoom="in"], .zoom-controls button[data-zoom="out"] { font-size: 20px; line-height: 1; }
.diagram-viewport { overflow: hidden; }
.diagram-svg { display: block; width: 100%; height: auto; color: var(--fg); touch-action: pan-y; }
.diagram-svg.is-zoomed { cursor: grab; }
.diagram-svg.is-zoomed:active { cursor: grabbing; }
.mobile-diagram { display: none; }
.diagram-svg text { fill: var(--fg); font-family: var(--font-app); }
.diagram-svg .label { font-size: 20px; font-weight: 500; letter-spacing: -.35px; }
.diagram-svg .small { font-size: 14px; fill: var(--text-muted); }
.diagram-svg .boundary-label { font-size: 19px; font-weight: 500; fill: var(--text-muted); letter-spacing: -.3px; }
.diagram-svg .boundary { fill: var(--surface); stroke: var(--rule); stroke-width: 1; }
.diagram-svg .node-box { fill: var(--bg); stroke: var(--dash); stroke-width: 1.2; }
.diagram-svg .wire { fill: none; stroke: var(--text-muted); stroke-width: 1.4; stroke-linejoin: round; }
.diagram-svg .dashed { stroke-dasharray: 4 5; }
.diagram-svg .arrow-tip { fill: var(--text-muted); }
.diagram-svg .icon { stroke: var(--fg); stroke-width: 1.4; fill: var(--bg); stroke-linecap: round; stroke-linejoin: round; }
.diagram-svg .icon path { fill: none; }
.diagram-svg .model .node-box, .diagram-svg .pilot-shape { fill: color-mix(in srgb, var(--activity) 7%, var(--bg)); stroke: var(--activity); stroke-width: 1.5; }
.diagram-svg .model .label, .diagram-svg .model .small { fill: var(--activity); }
.diagram-svg .network-link { stroke: var(--dash); stroke-width: 1.4; fill: none; }
.diagram-svg .network-node { fill: var(--bg); stroke: var(--fg); stroke-width: 1.8; }
.diagram-svg .network-node.entity { fill: var(--fg); }
.diagram-svg .network-label { font-size: 20px; fill: var(--text-note); }
.diagram-svg [data-part="network"] .part { transition: opacity .25s; }
.diagram-svg [data-part="network"] .part:hover .network-node { stroke-width: 3; }
.diagram-svg .camera > .part { transition: opacity .3s; }
.diagram-svg.has-focus .camera > .part:not(.is-focused):not([data-part="boundary"]) { opacity: .25; }
.diagram-svg.has-focus .camera > .wire { opacity: .3; }
.diagram-svg [data-part="external-clients"] .label { font-size: 18px; }
figcaption { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin: 0 22px; padding: 18px 0; border-top: 1px solid var(--rule); color: var(--text-muted); font: var(--type-meta); }
figcaption a { text-decoration: none; color: var(--fg); }
figcaption a span { margin-left: 10px; color: var(--activity); }
.model-key, .node-key, .node-key > span { display: inline-flex; align-items: center; gap: 8px; }
.model-key i { width: 7px; height: 7px; border-radius: 50%; background: var(--activity); }
.node-key { gap: 20px; }
.node-key i { display: inline-block; width: 9px; height: 9px; border: 1.3px solid var(--fg); }
.node-key .circle { border-radius: 50%; }
.node-key .diamond { transform: rotate(45deg); }
footer { display: flex; justify-content: space-between; padding: 28px 0 40px; border-top: 1px solid var(--rule); color: var(--text-muted); font: var(--type-meta); }
footer a { text-decoration: none; }
@media (max-width: 700px) {
 .wrap { width: calc(100% - 36px); }
 .top { min-height: 88px; gap: 16px; }
 .lockup { font-size: 22px; }
 .palette-picker { max-width: 148px; }
 .palette { width: 26px; height: 28px; padding: 5px; }
 .hero { padding: 38px 0 28px; }
 .hero-bottom { display: block; margin-top: 18px; }
 .hero-bottom p { font-size: 18px; }
 .down-link { display: inline-block; margin-top: 18px; }
 .chapter-nav { top: 88px; gap: 22px; font-size: 13px; }
 .chapter-nav a span { margin-right: 6px; }
 .chapter { padding: 32px 0; }
 .chapter-heading { display: block; margin-bottom: 22px; }
 h2 { font-size: 29px; }
 .chapter-heading > p { margin-top: 14px; font-size: 15px; }
 .desktop-break { display: none; }
 .diagram-toolbar { padding: 12px 10px 0; gap: 4px; }
 .diagram-toolbar button { padding: 6px 9px; }
 .focus-controls, .zoom-controls { gap: 0; }
 .desktop-diagram { display: none; }
 .mobile-diagram { display: block; }
 .mobile-diagram .label { font-size: 23px; }
 .mobile-diagram .small { font-size: 20px; }
 .mobile-diagram [data-part="external-clients"] .label { font-size: 23px; }
 .mobile-diagram .network-label { font-size: 24px; }
 figcaption { margin: 0 14px; font-size: 11px; gap: 16px; flex-wrap: wrap; }
 .node-key { gap: 14px; }
}
@media (prefers-reduced-motion: reduce) {
 html { scroll-behavior: auto; }
 *, *::before, *::after { transition: none !important; animation: none !important; }
}
/* Scroll narrative. The diagram is a fixed reading companion; the document
   keeps normal scroll mechanics. No content is hidden without enhancement. */
.chapter-nav { display: block; }
.chapter-nav > .wrap { display: flex; align-items: center; gap: 34px; }
.chapter-count { margin-left: auto; color: var(--text-muted); font: 11px var(--font-mono); }
.story-shell { width: min(1440px, calc(100% - 80px)); margin-inline: auto; }
.story-step { padding: 65px 0; border-bottom: 1px solid var(--rule); }
.step-copy { max-width: 620px; }
.step-prose { font: var(--type-prose); color: var(--text-note); }
.step-prose p { margin: 22px 0 0; }
.step-prose strong { color: var(--fg); font-weight: 600; }
.step-prose blockquote { margin: 26px 0 0; padding: 1px 0 1px 22px; border-left: 2px solid var(--activity); font-size: 18px; line-height: 1.5; }
.step-prose blockquote p { margin: 8px 0; }
.story-visual { min-width: 0; }
.visual-header, .visual-footer { display: flex; align-items: center; justify-content: space-between; gap: 14px; padding: 18px 22px; }
.visual-title { font: var(--type-meta); color: var(--text-muted); }
.visual-header .model-key { font: var(--type-meta); color: var(--text-muted); }
.visual-footer { border-top: 1px solid var(--rule); }
.step-index { display: flex; gap: 4px; flex-wrap: wrap; }
.step-index a { display: grid; place-items: center; width: 24px; height: 28px; text-decoration: none; color: var(--text-muted); font: 10px var(--font-mono); border-radius: 3px; position: relative; }
.step-index a::after { content: ''; position: absolute; bottom: 0; width: 12px; height: 2px; background: var(--rule); }
.step-index a[aria-current] { color: var(--fg); background: var(--surface); }
.step-index a[aria-current]::after { background: var(--activity); }
.step-controls { display: flex; gap: 4px; }
.step-controls button { width: 32px; height: 32px; border: 1px solid var(--rule); background: var(--bg); border-radius: var(--r-sm); cursor: pointer; }
.step-controls button:hover { border-color: var(--fg); }
.step-controls button:disabled { opacity: .3; cursor: default; }
.motion-note { text-align: center; margin: 10px 0 0; font: var(--type-meta); color: var(--text-muted); }
.motion-note span { margin-left: 8px; }
.story-canvas .scene { border: none; border-radius: 0; }
.story-canvas { overflow: hidden; }
.story-visual { border: 1px solid var(--rule); border-radius: var(--r-card); background: var(--bg); }
.story-visual > .motion-note { padding-bottom: 12px; }
.story-enhanced .story-shell { display: grid; grid-template-columns: minmax(280px, .92fr) minmax(0, 2fr); gap: 60px; align-items: start; position: relative; }
.story-enhanced .story-visual { grid-column: 2; grid-row: 1; position: sticky; top: 178px; height: calc(100svh - 206px); min-height: 360px; max-height: 820px; display: flex; flex-direction: column; margin-top: 26px; }
.story-enhanced .story-steps { grid-column: 1; grid-row: 1; }
.story-enhanced .story-step { min-height: 95svh; display: flex; align-items: center; border: none; padding: 65px 0; scroll-margin-top: 10px; }
.story-enhanced .step-copy { transition: opacity .45s, transform .45s; opacity: .35; transform: translateY(8px); }
.story-enhanced .story-step.is-active .step-copy { opacity: 1; transform: none; }
.story-enhanced .story-step h2 { font-size: clamp(29px, 2.8vw, 42px); line-height: 1.06; }
.story-enhanced .step-prose { font-size: clamp(18px, 1.65vw, 22px); line-height: 1.5; }
.story-enhanced .story-canvas { position: relative; flex: 1; min-height: 0; }
.story-enhanced .story-canvas .scene { position: absolute; inset: 0; opacity: 0; visibility: hidden; transition: opacity .55s, visibility .55s; background: transparent; }
.story-enhanced .story-canvas .scene.is-active { opacity: 1; visibility: visible; }
.story-enhanced .diagram-svg { height: 100%; }
.story-enhanced .diagram-svg .part, .story-enhanced .diagram-svg .connection, .story-enhanced [data-network] { transition: opacity .45s; }
.story-enhanced .diagram-svg .is-hidden { opacity: 0 !important; pointer-events: none; }
.story-enhanced .diagram-svg .is-muted { opacity: .18; }
.story-enhanced .diagram-svg .is-spotlit > .node-box,
.story-enhanced .diagram-svg .is-spotlit > .pilot-shape { stroke-width: 2; filter: drop-shadow(0 0 7px color-mix(in srgb, var(--fg) 12%, transparent)); }
.story-enhanced .diagram-svg .model.is-spotlit > .node-box,
.story-enhanced .diagram-svg .model.is-spotlit > .pilot-shape { filter: drop-shadow(0 0 9px color-mix(in srgb, var(--activity) 25%, transparent)); }
.story-enhanced .diagram-svg .network-highlight .network-node { stroke-width: 3; filter: drop-shadow(0 0 6px color-mix(in srgb, var(--fg) 30%, transparent)); }
.story-enhanced .diagram-svg .is-flowing .wire { stroke-dasharray: 6 10; animation: flow 1.4s linear 3; }
.story-enhanced .diagram-svg .is-flowing .arrow-tip { opacity: 1; }
.diagram-svg [data-effect] { opacity: 0; pointer-events: none; }
.diagram-svg .projection-beam { fill: color-mix(in srgb, var(--fg) 5%, transparent); stroke: color-mix(in srgb, var(--fg) 10%, transparent); stroke-width: .5; }
.story-enhanced .diagram-svg.projecting [data-effect="projection"] { opacity: 1; animation: projection 2.2s ease-in-out 2; }
.story-enhanced .diagram-svg.model-focus .model > .node-box { animation: model-glow 2.2s ease-in-out 2; }
.story-enhanced .diagram-svg.private-focus .boundary { stroke: var(--fg); stroke-width: 2; }
@keyframes flow { to { stroke-dashoffset: -32; } }
@keyframes projection { 0%,100% { opacity: .35; } 50% { opacity: 1; } }
@keyframes model-glow { 0%,100% { filter: drop-shadow(0 0 2px color-mix(in srgb, var(--activity) 10%, transparent)); } 50% { filter: drop-shadow(0 0 12px color-mix(in srgb, var(--activity) 35%, transparent)); } }
@media (max-width: 1050px) and (min-width: 701px) {
 .story-shell { width: calc(100% - 44px); }
 .story-enhanced .story-shell { gap: 26px; grid-template-columns: minmax(230px, .85fr) minmax(0, 1.8fr); }
 .step-index { gap: 0; }
 .step-index a { width: 19px; }
 .visual-header, .visual-footer { padding-inline: 12px; }
 .step-controls { display: none; }
}
@media (max-width: 700px) {
 html { scroll-padding-top: 150px; }
 .chapter-nav > .wrap { gap: 20px; }
 .chapter-nav a { font-size: 12px; }
 .chapter-nav a span { font-size: 9px; }
 .chapter-count { font-size: 9px; }
 .story-shell { width: calc(100% - 36px); }
 .story-enhanced .story-shell { display: block; }
 .story-enhanced .story-visual { top: 145px; height: 43svh; min-height: 250px; max-height: 440px; z-index: 5; margin-top: 18px; box-shadow: 0 14px 20px -16px var(--bg); }
 .story-enhanced .story-step { min-height: 82svh; padding: 40px 6px 65px; align-items: flex-start; scroll-margin-top: 44svh; }
 .story-enhanced .story-step h2 { font-size: 32px; max-width: 330px; }
 .story-enhanced .step-prose { font-size: 19px; }
 .story-enhanced .step-copy { max-width: none; }
 .step-prose blockquote { font-size: 17px; }
 .visual-header { padding: 10px 13px 0; }
 .visual-header .model-key, .visual-title { font-size: 10px; }
 .visual-footer { padding: 5px 10px; }
 .step-index { gap: 1px; justify-content: space-between; width: 100%; }
 .step-index a { width: 17px; height: 25px; font-size: 8px; }
 .step-controls { display: none; }
 .story-visual > .motion-note { display: none; }
}
@media (prefers-reduced-motion: reduce) {
 .story-enhanced .step-copy { transform: none; }
 .story-enhanced .diagram-svg .is-flowing .wire { stroke-dasharray: none; }
}

html:not(.story-enhanced) [data-link^="intro-"], html:not(.story-enhanced) [data-link^="direct-"] { display: none; }
.story-enhanced .scene:not(.is-active) * { animation-play-state: paused !important; }
/* Match the vault box to its interior scene, rather than crossfading two
   unrelated frames. The scene transform is temporary and cancellation-safe. */
.story-enhanced .story-canvas .scene.is-portal {
  z-index: 3;
  opacity: 1;
  visibility: visible;
  transition: none;
  transform-origin: 0 0;
  background: var(--bg);
  border-radius: 8px;
}
.diagram-svg [data-part="external-services"] .label,
.diagram-svg [data-part="external-services"] .small { font-size: 17px; }
.mobile-diagram [data-part="external-services"] .label,
.mobile-diagram [data-part="external-services"] .small { font-size: 22px; }
.step-prose > :first-child { margin-top: 0; }
.story-enhanced .scene.portal-settled,
.story-enhanced .scene.setting-state * { transition: none !important; }
/* The same tint identifies the vault at both scales. */
.diagram-svg {
  --vault-fill: color-mix(in srgb, var(--activity) 10%, var(--bg));
  --vault-edge: color-mix(in srgb, var(--activity) 55%, var(--bg));
}
.diagram-svg [data-part="vault"] .node-box,
.diagram-svg[data-scene="vault"] .boundary { fill: var(--vault-fill); stroke: var(--vault-edge); }
.diagram-svg [data-part="vault"] .icon { fill: var(--vault-fill); }
.diagram-svg [data-part="vault"] .label,
.diagram-svg[data-scene="vault"] .boundary-label { fill: var(--activity); }
.story-enhanced .diagram-svg[data-scene="vault"].private-focus .boundary { stroke: var(--activity); }

.power-user { position: relative; display: inline-block; color: var(--activity); white-space: nowrap; }
.sparkle { position: absolute; pointer-events: none; opacity: 0; font-style: normal; line-height: 1; transform: scale(.2); }
.sparkle-one { left: -11px; top: -8px; font-size: 12px; }
.sparkle-two { right: -10px; top: -5px; font-size: 10px; }
.sparkle-three { right: 9px; bottom: -7px; font-size: 9px; }
.story-step.is-active .sparkle { animation: power-sparkle 1.6s ease-in-out 2; }
.story-step.is-active .sparkle-two { animation-delay: .2s; }
.story-step.is-active .sparkle-three { animation-delay: .4s; }
@keyframes power-sparkle {
  0%, 100% { opacity: 0; transform: translateY(2px) rotate(-25deg) scale(.2); }
  35%, 60% { opacity: .85; transform: translateY(-2px) rotate(15deg) scale(1); }
}
@media (prefers-reduced-motion: reduce) {
  .sparkle { display: none; }
}

.story-cta { display: flex; justify-content: center; padding: 72px 0 96px; }