:root {
  --ink: #172026;
  --muted: #526169;
  --line: #d9e1e4;
  --paper: #ffffff;
  --soft: #f3f7f7;
  --teal: #155e75;
  --teal-dark: #0e4658;
  --coral: #c2413a;
  --focus: #f3b61f;
  --calibration-pixels: 189;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.6; }
button, select { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
a { color: var(--teal-dark); }
a:hover { color: var(--coral); }
[hidden] { display: none !important; }
.visually-hidden { position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
.skip-link { position: fixed; left: 1rem; top: 1rem; z-index: 100; padding: .65rem .9rem; color: #fff; background: var(--ink); transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }
.site-header { border-bottom: 1px solid var(--line); background: rgba(255, 255, 255, .96); }
.header-inner, .footer-inner, .footer-bottom, .content-wide, .content-narrow, .tool-shell, .ad-wrap { width: min(100% - 2rem, 1120px); margin-inline: auto; }
.content-narrow { max-width: 820px; }
.header-inner { min-height: 68px; display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.brand { display: inline-flex; align-items: center; gap: .7rem; color: var(--ink); font-weight: 780; text-decoration: none; }
.brand-logo-mark { width: 52px; height: 38px; display: block; object-fit: contain; }
.site-header nav, .site-footer nav { display: flex; align-items: center; gap: 1.2rem; }
.site-header nav a, .site-footer nav a { color: var(--ink); text-decoration: none; }
.intro-band { padding: 4.5rem 0 3.5rem; background: var(--soft); border-bottom: 1px solid var(--line); }
.eyebrow { margin: 0 0 .4rem; color: var(--teal); font-size: .78rem; font-weight: 800; letter-spacing: 0; text-transform: uppercase; }
h1, h2 { margin-top: 0; font-family: Georgia, "Times New Roman", serif; line-height: 1.12; letter-spacing: 0; }
h1 { max-width: 760px; margin-bottom: 1rem; font-size: 4.6rem; }
h2 { margin-bottom: .75rem; font-size: 1.7rem; }
p { margin-top: 0; }
.lede { max-width: 730px; color: var(--muted); font-size: 1.16rem; }
.medical-notice { max-width: 760px; margin-top: 1.5rem; padding: 1rem 1.15rem; border-left: 4px solid var(--coral); background: #fff; }
.intro-actions { margin-top: 1.5rem; display: flex; flex-wrap: wrap; align-items: center; gap: .8rem 1.2rem; }
.primary-link { display: inline-flex; min-height: 48px; align-items: center; padding: .65rem 1.15rem; border: 1px solid var(--teal); border-radius: 4px; color: #fff; background: var(--teal); font-weight: 750; text-decoration: none; }
.primary-link:hover { border-color: var(--teal-dark); color: #fff; background: var(--teal-dark); }
.quiet-link, .inline-action { color: var(--teal-dark); font-weight: 750; text-underline-offset: 4px; }
.quiet-link:hover, .inline-action:hover { color: var(--coral); }
.tool-band { padding: 3rem 0; }
.tool-band, #calibrate, .how-band, .faq-band, #compare-glasses { scroll-margin-top: 1rem; }
.tool-shell { max-width: 900px; border: 1px solid var(--line); border-radius: 8px; padding: clamp(1.2rem, 4vw, 2.5rem); box-shadow: 0 16px 45px rgba(23, 32, 38, .08); }
.step-heading { display: grid; grid-template-columns: 42px 1fr; gap: 1rem; align-items: start; }
.step-heading p { margin-bottom: 0; color: var(--muted); }
.step-number { width: 38px; height: 38px; display: grid; place-items: center; border-radius: 50%; color: #fff; background: var(--teal); font-weight: 800; }
.step-divider { height: 1px; margin: 2.4rem 0; background: var(--line); }
.calibration-area { margin: 1.7rem 0 0 58px; padding: 1.5rem; text-align: center; background: var(--soft); }
#calBar { width: calc(var(--calibration-pixels) * 1px); max-width: 100%; height: 8px; margin: .6rem auto .75rem; background: #111; }
.calibration-controls { min-height: 48px; margin-top: 1.25rem; display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: .55rem; }
.calibration-controls button { width: 54px; min-height: 44px; border: 1px solid #aebbc0; border-radius: 4px; color: var(--ink); background: #fff; cursor: pointer; }
.calibration-controls button:hover { border-color: var(--teal); background: #e7f0f2; }
.pixel-readout { min-width: 88px; font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-weight: 700; }
.test-options { margin: 1.5rem 0 0 58px; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
.test-options label { color: var(--muted); font-size: .86rem; font-weight: 750; }
select { width: 100%; min-height: 48px; margin-top: .35rem; padding: .6rem .75rem; border: 1px solid #aebbc0; border-radius: 4px; color: var(--ink); background: #fff; }
.start-row { margin: 1.5rem 0 0 58px; display: flex; align-items: center; gap: 1rem; }
.start-row p { margin: 0; color: var(--muted); font-size: .82rem; }
.primary-button { min-height: 48px; padding: .7rem 1.2rem; border: 1px solid var(--teal); border-radius: 4px; color: #fff; background: var(--teal); font-weight: 750; cursor: pointer; }
.primary-button:hover { border-color: var(--teal-dark); background: var(--teal-dark); }
.text-button { padding: .5rem; border: 0; color: var(--teal-dark); background: transparent; text-decoration: underline; cursor: pointer; }
button:focus-visible, select:focus-visible, a:focus-visible, summary:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
.test-status { display: flex; flex-wrap: wrap; justify-content: center; gap: .5rem 1rem; color: var(--muted); font-size: .82rem; }
.test-status span { white-space: nowrap; }
#optotypeBox { min-height: 360px; display: flex; align-items: center; justify-content: center; overflow: hidden; }
#eSvg { display: block; fill: #070a0b; }
.direction-title { margin-bottom: 1rem; text-align: center; font-size: 1.3rem; }
.direction-buttons { min-height: 62px; display: flex; justify-content: center; gap: .7rem; }
.direction-buttons button { width: 62px; height: 58px; padding: 0; border: 1px solid #aebbc0; border-radius: 4px; color: var(--ink); background: #fff; font-size: 2rem; line-height: 1; cursor: pointer; }
.direction-buttons button:hover { border-color: var(--teal); background: #e7f0f2; }
.direction-buttons button:disabled { opacity: .45; cursor: not-allowed; }
.keyboard-hint { margin: .9rem 0 1.5rem; color: var(--muted); font-size: .85rem; text-align: center; }
.result-panel { max-width: 600px; margin: 1.5rem auto; padding: 1.4rem; border: 1px solid #a8ced8; border-radius: 8px; background: #edf7f8; text-align: center; }
.result-label { margin-bottom: .2rem; color: var(--muted); font-size: .82rem; font-weight: 800; text-transform: uppercase; }
.result-value { margin-bottom: .5rem; font-family: Georgia, serif; font-size: 2rem; font-weight: 800; line-height: 1.15; }
.result-caution { color: var(--muted); font-size: .9rem; }
.ad-wrap { min-height: 100px; margin-block: 1rem 3rem; display: grid; place-items: center; overflow: hidden; }
.ad-label { color: #718087; font-size: .68rem; text-align: center; text-transform: uppercase; }
.responsive-ad { width: 100%; display: block; }
.how-band { padding: 4.5rem 0; border-top: 1px solid var(--line); background: #fff; }
.how-page-title { max-width: none; margin-bottom: 0; font-size: 2.4rem; }
.section-heading { margin-bottom: 2.25rem; display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(280px, .8fr); gap: 2rem; align-items: end; }
.section-heading h2 { margin-bottom: 0; font-size: 2.4rem; }
.section-heading > p { max-width: 420px; margin: 0; color: var(--muted); }
.how-steps { margin: 0 0 2rem; padding: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); list-style: none; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.how-steps li { min-height: 260px; padding: 1.5rem 1.3rem 1.5rem 0; display: flex; flex-direction: column; gap: 1.2rem; }
.how-steps li + li { padding-left: 1.3rem; border-left: 1px solid var(--line); }
.how-number { width: 36px; height: 36px; display: grid; place-items: center; border-radius: 50%; color: #fff; background: var(--teal); font-weight: 800; }
.how-steps h3, .related-item h3 { margin: 0 0 .55rem; font-family: Georgia, "Times New Roman", serif; font-size: 1.25rem; line-height: 1.2; }
.how-steps p, .related-item p { margin: 0; color: var(--muted); font-size: .93rem; }
.info-band { padding: 4.5rem 0; color: #f7fbfc; background: #17343d; }
.info-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: clamp(2rem, 7vw, 5.5rem); }
.info-grid .eyebrow { color: #75d1d4; }
.info-grid p:not(.eyebrow) { color: #c8d9dd; }
.privacy-band { padding: 4.5rem 0; border-bottom: 1px solid var(--line); background: #eaf4f4; }
.privacy-layout { display: grid; grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr); gap: clamp(2.5rem, 8vw, 6rem); align-items: center; }
.privacy-copy h2 { max-width: 500px; font-size: 2.4rem; }
.privacy-copy > p:not(.eyebrow) { max-width: 530px; color: var(--muted); }
.privacy-points { margin: 0; padding: 0; list-style: none; border-top: 1px solid #b9d2d5; }
.privacy-points li { padding: 1.2rem 0; display: grid; grid-template-columns: 150px 1fr; gap: 1rem; border-bottom: 1px solid #b9d2d5; }
.privacy-points strong { color: var(--teal-dark); }
.privacy-points span { color: var(--muted); }
.guidance-band { padding: 4rem 0; background: var(--soft); }
.guidance-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; }
.urgent-note { padding-left: 1.5rem; border-left: 4px solid var(--coral); }
.faq-band { padding: 4rem 0; }
.faq-band > div > h2 { margin-bottom: 1.5rem; }
details { border-top: 1px solid var(--line); }
details:last-child { border-bottom: 1px solid var(--line); }
summary { padding: 1.1rem 2rem 1.1rem 0; font-weight: 750; cursor: pointer; }
details p { max-width: 700px; padding: 0 0 1.2rem; color: var(--muted); }
.related-band { padding: 4.5rem 0; border-top: 1px solid var(--line); background: var(--soft); }
.related-heading { margin-bottom: 1.8rem; }
.related-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
.related-item { min-height: 310px; padding: 1.35rem; display: flex; flex-direction: column; border: 1px solid var(--line); border-radius: 8px; color: var(--ink); background: #fff; text-decoration: none; transition: border-color 160ms ease, transform 160ms ease, box-shadow 160ms ease; }
.related-item:hover { border-color: #8eb9c2; color: var(--ink); transform: translateY(-2px); box-shadow: 0 12px 25px rgba(23, 32, 38, .08); }
.related-symbol { width: 48px; height: 48px; margin-bottom: 1.5rem; display: grid; place-items: center; border: 1px solid #a8ced8; border-radius: 4px; color: var(--teal-dark); background: #edf7f8; font-size: .9rem; font-weight: 850; }
.related-e { font-family: Georgia, serif; font-size: 1.6rem; }
.related-kicker { margin-bottom: .45rem; color: var(--teal); font-size: .72rem; font-weight: 850; text-transform: uppercase; }
.related-action { margin-top: auto; padding-top: 1.5rem; color: var(--teal-dark); font-weight: 750; text-decoration: underline; text-underline-offset: 4px; }
.site-footer { padding: 3rem 0 0; border-top: 1px solid var(--line); background: var(--soft); }
.footer-inner { display: flex; justify-content: space-between; gap: 2rem; }
.footer-inner p { margin: .8rem 0 0; color: var(--muted); }
.footer-logo-link { display: inline-block; color: inherit; }
.footer-logo { width: 185px; height: auto; display: block; }
.footer-link { padding: 0; border: 0; color: var(--ink); background: transparent; cursor: pointer; }
.footer-bottom { margin-top: 2.5rem; padding-block: 1rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .78rem; }
.legal-main { min-height: 65vh; padding: 4rem 0; }
.legal-main h1 { font-size: 3rem; }
.legal-main h2 { margin-top: 2.4rem; font-size: 1.45rem; }
.legal-main li { margin-bottom: .6rem; }
.legal-main .updated { color: var(--muted); font-size: .85rem; }
.legal-main .callout { margin: 2rem 0; padding: 1rem 1.2rem; border-left: 4px solid var(--teal); background: var(--soft); }
@media (max-width: 720px) {
  .site-header .nav-optional { display: none; }
  .intro-band { padding: 3rem 0 2.5rem; }
  h1 { font-size: 2.65rem; }
  .tool-band { padding: 1.5rem 0 2.5rem; }
  .tool-shell { width: min(100% - 1rem, 900px); padding: 1.2rem; }
  .calibration-area, .test-options, .start-row { margin-left: 0; }
  .calibration-area { padding-inline: .6rem; }
  .test-options, .info-grid, .guidance-grid, .privacy-layout, .related-grid { grid-template-columns: 1fr; }
  .section-heading { grid-template-columns: 1fr; gap: .75rem; }
  .section-heading h2, .privacy-copy h2 { font-size: 2rem; }
  .how-steps { grid-template-columns: 1fr; }
  .how-steps li { min-height: 0; padding: 1.3rem 0; display: grid; grid-template-columns: 40px 1fr; gap: 1rem; }
  .how-steps li + li { padding-left: 0; border-top: 1px solid var(--line); border-left: 0; }
  .privacy-points li { grid-template-columns: 1fr; gap: .15rem; }
  .related-item { min-height: 270px; }
  .start-row { align-items: stretch; flex-direction: column; }
  #optotypeBox { min-height: 310px; }
  .direction-buttons { gap: .4rem; }
  .direction-buttons button { width: 56px; }
  .guidance-grid { gap: 2rem; }
  .footer-inner { flex-direction: column; }
  .site-footer nav { flex-wrap: wrap; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }