@font-face { font-family: Gellix; src: url('assets/gellix-semibold.otf') format('opentype'); font-weight: 600; font-display: swap; }
@font-face { font-family: 'Helvetica Now'; src: url('assets/helvetica-now-text.ttf') format('truetype'); font-weight: 400; font-display: swap; }
:root {
  color-scheme: light;
  --navy: oklch(18% .045 282); --purple: oklch(54% .235 294); --purple-deep: oklch(42% .17 294);
  --paper: oklch(99% .003 285); --wash: oklch(97% .012 292); --lavender: oklch(94% .035 295);
  --ink: oklch(24% .04 280); --muted: oklch(46% .035 270); --line: oklch(87% .022 285);
  --success: oklch(39% .08 175); --error: oklch(43% .16 22);
  --space-sm: .5rem; --space-md: 1rem; --space-lg: 1.5rem; --space-xl: 2rem; --space-section: 5rem;
  font-family: 'Helvetica Now', sans-serif; font-size: 16px; color: var(--ink); background: var(--paper); line-height: 1.65;
}
* { box-sizing: border-box; }
body { margin: 0; }
a { color: var(--purple-deep); text-underline-offset: .25em; }
button, input { font: inherit; }
button, .button { cursor: pointer; }
button:disabled { cursor: wait; opacity: .55; }
button:focus-visible, a:focus-visible, input:focus-visible, summary:focus-visible { outline: 3px solid var(--purple); outline-offset: 4px; }
[hidden] { display: none !important; }
h1, h2, h3 { font-family: Gellix, sans-serif; font-weight: 600; line-height: 1.1; margin: 0; text-wrap: balance; }
h1 { font-size: clamp(3.5rem, 6.3vw, 6rem); letter-spacing: -.055em; }
h2 { font-size: clamp(2rem, 3.1vw, 3rem); letter-spacing: -.035em; }
h3 { font-size: 1.65rem; letter-spacing: -.02em; }
p { margin: 0; max-width: 70ch; }
code, pre { font-family: 'SFMono-Regular', Consolas, monospace; overflow-wrap: anywhere; }
.shell { max-width: 1248px; margin-inline: auto; padding-inline: clamp(1.25rem, 4vw, 3.5rem); }
.masthead { min-height: 100px; display: flex; gap: 2rem; align-items: center; border-bottom: 1px solid var(--line); }
.brand { display: flex; flex-shrink: 0; }
.brand img { width: 113px; height: auto; }
.lab-label { font-size: .95rem; line-height: 1.4; border-left: 1px solid var(--line); padding-left: 2rem; }
.lab-label span { display: block; font-size: .75rem; color: var(--muted); }
.header-link { margin-left: auto; font-size: .875rem; text-decoration: none; }
.intro { padding-block: 4.5rem 4rem; display: grid; grid-template-columns: 1.5fr 1fr; gap: 5rem; align-items: center; }
.eyebrow { font-size: .75rem; letter-spacing: .12em; text-transform: uppercase; font-weight: 600; color: var(--purple-deep); margin-bottom: 1rem; }
.intro-copy { font-size: 1.125rem; color: var(--muted); max-width: 46ch; margin-top: 1.5rem; }
.setup-line { font-size: .8rem; margin-top: 1.5rem; }
.setup-line span { color: var(--success); margin-right: .4rem; }
.question-note { padding: 2rem 0 2rem 2.5rem; border-left: 1px solid var(--line); }
.question-note p { font-family: Gellix, sans-serif; font-size: 1.5rem; line-height: 1.4; margin-block: 1rem 1.5rem; }
.question-note strong { color: var(--purple-deep); font-weight: 600; }
.question-note a { font-size: .875rem; }
.small-label, .step-label { display: block; font-size: .72rem; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
.section-heading { display: flex; gap: 1rem; align-items: end; justify-content: space-between; }
.time-note { color: var(--muted); font-size: .85rem; }
.tour-instructions { color: var(--muted); margin-block: 1rem 1.75rem; font-size: .95rem; }
.journey { display: grid; grid-template-columns: repeat(5, 1fr); border-bottom: 1px solid var(--line); margin-bottom: 1.5rem; }
.journey a { color: var(--muted); text-decoration: none; display: flex; align-items: center; gap: .7rem; padding: 1rem .75rem; border-bottom: 3px solid transparent; font-size: .875rem; }
.journey a[aria-current='step'] { border-bottom-color: var(--purple); color: var(--purple-deep); background: var(--wash); }
.journey .step-number { border: 1px solid var(--line); border-radius: 50%; width: 1.7rem; height: 1.7rem; display: grid; place-items: center; font-size: .75rem; flex-shrink: 0; }
.journey a[aria-current='step'] .step-number { background: var(--purple); color: var(--paper); border-color: var(--purple); }
.journey a[data-visited='true'] .step-number { border-color: var(--success); color: var(--success); }
.workbench { display: grid; grid-template-columns: 1fr 1fr; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.context-panel, .result-panel { padding: clamp(1.25rem, 3vw, 2rem); min-width: 0; }
.context-panel { background: var(--wash); }
.context-heading { display: flex; gap: .75rem; align-items: center; justify-content: space-between; margin-bottom: 1rem; }
.context-kind { color: var(--purple-deep); font-size: .72rem; }
.context-panel h3 { font-size: 2rem; margin-bottom: .75rem; }
#step-description { font-size: .9rem; color: var(--muted); min-height: 3rem; }
.address { margin-block: 1.5rem 1rem; }
.address code { font-size: .75rem; display: block; margin-top: .4rem; }
.frame-wrap { border: 1px solid var(--line); border-radius: 6px; background: var(--paper); overflow: hidden; }
.frame-caption { display: flex; gap: .5rem; flex-wrap: wrap; justify-content: space-between; background: var(--lavender); padding: .6rem .9rem; font-size: .65rem; color: var(--purple-deep); }
.frame-caption strong { font-weight: 400; }
iframe { width: 100%; height: 270px; border: 0; display: block; }
.caption { font-size: .75rem; color: var(--muted); line-height: 1.6; }
.context-panel > .caption { margin-top: .75rem; }
.result-panel { display: flex; flex-direction: column; gap: 1rem; }
#result-title { font-size: 2rem; }
#result-description { margin-top: .65rem; font-size: .9rem; color: var(--muted); }
.result-panel[data-comparison='different'] #result-title, .result-panel[data-state='error'] #result-title { color: var(--error); }
.fingerprint-block { padding-block: 1rem; border-block: 1px solid var(--line); }
#fingerprint { display: block; font-size: .88rem; letter-spacing: .015em; margin-block: .65rem .25rem; line-height: 1.8; }
.text-button { background: none; color: var(--purple-deep); border: 0; padding: .5rem 0; text-decoration: underline; text-underline-offset: .25em; font-size: .8rem; min-height: 44px; }
#copy-status { margin-left: .5rem; }
.checks { padding: 0; margin: 0; list-style: none; font-size: .8rem; color: var(--muted); display: grid; gap: .35rem; }
.checks li[data-pass='true'] { color: var(--success); }
.actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: auto; }
.button { border-radius: 5px; display: inline-flex; align-items: center; justify-content: center; gap: .8rem; text-decoration: none; padding: .75rem 1.1rem; font-size: .875rem; min-height: 48px; border: 1px solid var(--purple); }
.primary { background: var(--purple); color: var(--paper); }
.secondary { background: transparent; color: var(--purple-deep); border-color: var(--line); }
.button:hover { background: var(--purple-deep); color: var(--paper); }
.button[aria-disabled='true'] { opacity: .45; cursor: wait; pointer-events: none; }
.notice { background: var(--lavender); padding: 1rem; margin-bottom: 1rem; border-radius: 4px; font-size: .875rem; }
.tour-results { display: grid; grid-template-columns: .8fr 1fr; gap: 3rem; margin-top: 2.5rem; padding-top: 2rem; border-top: 1px solid var(--line); }
.tour-results p:not(.eyebrow) { font-size: .9rem; color: var(--muted); margin-top: .8rem; }
.table-scroll { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; text-align: left; font-size: .8rem; }
th { font-weight: 400; color: var(--muted); font-size: .72rem; }
th, td { padding: .75rem .5rem; border-bottom: 1px solid var(--line); }
.below-tools { display: flex; align-items: center; gap: 1.5rem; margin-block: 1rem .5rem; font-size: .8rem; flex-wrap: wrap; }
.technical { margin-top: 1.75rem; border-block: 1px solid var(--line); }
summary { cursor: pointer; padding: 1.2rem 0; font-family: Gellix, sans-serif; font-weight: 600; font-size: 1.05rem; }
.details-content { padding-bottom: 1.5rem; }
#context { font-size: .8rem; overflow-wrap: anywhere; margin-bottom: 1rem; }
label { display: block; font-size: .9rem; }
input { display: block; width: 100%; padding: .75rem; border: 1px solid var(--line); background: var(--paper); border-radius: 4px; margin-block: .5rem; color: var(--ink); }
#comparison { font-size: .9rem; margin-bottom: .5rem; }
pre { white-space: pre-wrap; font-size: .75rem; padding: 1.25rem; background: var(--wash); max-height: 28rem; overflow: auto; }
.explanation { background: var(--navy); color: var(--paper); margin-top: var(--space-section); padding-block: var(--space-section); }
.explanation-grid { display: grid; grid-template-columns: 1fr 1.2fr; gap: 5rem; }
.explanation .eyebrow { color: oklch(80% .12 294); }
.section-intro { color: oklch(83% .03 285); margin-top: 1.5rem; font-size: 1rem; }
.concepts { display: grid; gap: 2rem; }
.concepts article { display: flex; gap: 1.25rem; }
.concept-number { color: oklch(80% .12 294); font-size: .8rem; padding-top: .25rem; }
.concepts h3 { font-size: 1.3rem; line-height: 1.3; }
.concepts p { color: oklch(83% .03 285); font-size: .9rem; margin-top: .75rem; }
.reading-section { display: grid; grid-template-columns: .8fr 1.2fr; gap: 5rem; padding-block: var(--space-section); }
.reading-section > div > p:last-child { margin-top: 1.25rem; color: var(--muted); }
.faq details { border-bottom: 1px solid var(--line); }
.faq details:first-child summary { padding-top: 0; }
.faq p { font-size: .9rem; margin-bottom: 1.25rem; color: var(--muted); }
.footer { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 1rem; border-top: 1px solid var(--line); padding-block: 1.75rem; font-size: .75rem; color: var(--muted); }
.embedded { padding: 1rem; background: var(--paper); }
.embedded-heading { display: flex; gap: .6rem; align-items: center; color: var(--purple-deep); }
.embedded h2 { font-size: 1.1rem; letter-spacing: -.01em; }
.embedded #status { font-size: .85rem; margin-block: .8rem; overflow-wrap: anywhere; }
.embedded-origin { display: block; font-size: .65rem; margin-bottom: .65rem; color: var(--muted); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.skip-link { position: absolute; top: -100px; left: 1rem; background: var(--paper); padding: 1rem; z-index: 5; }
.skip-link:focus { top: 1rem; }
@media (max-width: 850px) {
  .intro { gap: 2rem; } .question-note { padding-left: 1.5rem; }
  .workbench, .explanation-grid, .reading-section { grid-template-columns: 1fr; }
  .explanation-grid, .reading-section { gap: 2.5rem; }
  .journey a { flex-direction: column; gap: .5rem; text-align: center; padding-inline: .25rem; font-size: .75rem; }
  .context-panel { border-bottom: 1px solid var(--line); }
  #step-description { min-height: 0; }
  iframe { height: 270px; }
  .tour-results { gap: 1.5rem; }
}
@media (max-width: 600px) {
  :root { --space-section: 3rem; }
  .masthead { min-height: 80px; gap: 1rem; }.lab-label { padding-left: 1rem; font-size: .8rem; }.header-link { display: none; }
  .brand img { width: 92px; }
  .intro { grid-template-columns: 1fr; gap: 2rem; padding-block: 2.5rem; }
  .question-note { padding: 1.5rem 0 0; border-left: 0; border-top: 1px solid var(--line); }
  .question-note p { font-size: 1.25rem; }
  .time-note { white-space: nowrap; font-size: .75rem; }
  .tour-results { grid-template-columns: 1fr; }
  .actions .button { flex: 1; }
  #result-title { font-size: 1.75rem; }
  .context-kind { max-width: 50%; text-align: right; }
}
@media (prefers-reduced-motion: no-preference) {
  .button, a { transition: background-color .15s ease-out, color .15s ease-out; }
}

.embedded #status[data-state='different'], .embedded #status[data-state='error'] { color: var(--error); font-weight: 600; }
.embedded #status[data-state='same'] { color: var(--success); font-weight: 600; }
.embedded #key-action { margin-bottom: .8rem; }

.mode-selector { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 24px; }
.mode-selector a { padding: 12px 18px; border: 1px solid var(--line); border-radius: 8px; }
.mode-selector a[aria-current] { background: var(--navy); color: white; }
#shared-instructions { margin-bottom: 28px; }
#shared-instructions li { margin-bottom: 10px; }
body[data-mode="shared"] #frame { height: 390px; }
#request-access { margin: 10px 0; }
[hidden] { display: none !important; }
.prepare { max-width: 720px; margin: 60px auto; padding: 24px; }