/* ============================================================
   CodePass
   A graphite keyboard case, porcelain keycaps, and one aqua
   backlight. Porcelain means "press this". Aqua is light: it
   marks keystrokes leaving the phone and the step you are on.
   Radii by role come from the app (dimens.xml).
   ============================================================ */

:root{
  /* light: brushed aluminium */
  --chassis:#EEEFF0;
  --plate:#FFFFFF;
  --plate-edge:rgba(255,255,255,1);
  --well:#E4E6E9;
  --cap:#F5F6F7;
  --cap-edge:#C8CCD1;
  --legend:#111315;
  --legend-body:#2D3136;
  --legend-soft:#555B62;
  --legend-faint:#737980;
  --rule:#D5D8DC;
  --rule-soft:#E6E8EB;
  --hover:rgba(17,19,21,.04);

  --key:#1D2024;
  --key-hi:#2D3136;
  --key-lo:#15171A;
  --key-edge:#000000;
  --key-ink:#F4F5F2;

  --signal:#0B7D67;
  --signal-text:#0A6B58;
  --signal-ink:#FFFFFF;
  --signal-soft:rgba(11,125,103,.10);
  --signal-line:rgba(11,125,103,.42);
  --signal-glow:rgba(11,125,103,.26);
  --signal-wash:rgba(11,125,103,.07);

  --well-shadow:rgba(17,19,21,.12);
  --panel-shadow:rgba(17,19,21,.10);
  --glow:rgba(255,255,255,.7);

  --r-plate:20px;
  --r-well:6px;
  --r-key:12px;

  --sans:"IBM Plex Sans","Segoe UI",system-ui,-apple-system,Helvetica,Arial,sans-serif;
  --mono:"IBM Plex Mono","SFMono-Regular",Consolas,"Liberation Mono",monospace;

  --shell:1120px;
  --gutter:clamp(18px,5vw,40px);
  --section:clamp(56px,7.5vw,104px);
}

@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --chassis:#0F1012;
    --plate:#17191C;
    --plate-edge:rgba(255,255,255,.06);
    --well:#0A0B0D;
    --cap:#202327;
    --cap-edge:#08090A;
    --legend:#F3F4F2;
    --legend-body:#D3D6D4;
    --legend-soft:#A3A8AD;
    --legend-faint:#7A8086;
    --rule:#2A2D32;
    --rule-soft:#1D2024;
    --hover:rgba(255,255,255,.04);

    --key:#E9EAE6;
    --key-hi:#F8F8F5;
    --key-lo:#D5D7D2;
    --key-edge:#8C908D;
    --key-ink:#0F1012;

    --signal:#7CDCC4;
    --signal-text:#8FE3CE;
    --signal-ink:#05211A;
    --signal-soft:rgba(124,220,196,.12);
    --signal-line:rgba(124,220,196,.45);
    --signal-glow:rgba(124,220,196,.34);
    --signal-wash:rgba(124,220,196,.075);

    --well-shadow:rgba(0,0,0,.6);
    --panel-shadow:rgba(0,0,0,.55);
    --glow:rgba(255,255,255,.035);
  }
}

:root[data-theme="dark"]{
  --chassis:#0F1012;
  --plate:#17191C;
  --plate-edge:rgba(255,255,255,.06);
  --well:#0A0B0D;
  --cap:#202327;
  --cap-edge:#08090A;
  --legend:#F3F4F2;
  --legend-body:#D3D6D4;
  --legend-soft:#A3A8AD;
  --legend-faint:#7A8086;
  --rule:#2A2D32;
  --rule-soft:#1D2024;
  --hover:rgba(255,255,255,.04);

  --key:#E9EAE6;
  --key-hi:#F8F8F5;
  --key-lo:#D5D7D2;
  --key-edge:#8C908D;
  --key-ink:#0F1012;

  --signal:#7CDCC4;
  --signal-text:#8FE3CE;
  --signal-ink:#05211A;
  --signal-soft:rgba(124,220,196,.12);
  --signal-line:rgba(124,220,196,.45);
  --signal-glow:rgba(124,220,196,.34);
  --signal-wash:rgba(124,220,196,.075);

  --well-shadow:rgba(0,0,0,.6);
  --panel-shadow:rgba(0,0,0,.55);
  --glow:rgba(255,255,255,.035);
}

*{box-sizing:border-box}
[hidden]{display:none !important}

body{
  margin:0;
  background:radial-gradient(1100px 520px at 50% -8%, var(--glow), transparent 68%), var(--chassis);
  background-attachment:fixed;
  color:var(--legend);
  font-family:var(--sans);
  font-size:16px;
  line-height:1.68;
  -webkit-font-smoothing:antialiased;
}

.shell{
  width:100%;
  max-width:var(--shell);
  margin:0 auto;
  padding-inline:var(--gutter);
}

h1,h2,h3{margin:0;text-wrap:balance;letter-spacing:-.02em;font-weight:600;line-height:1.15}
p{margin:0}
a{color:inherit}
strong{font-weight:600;color:var(--legend)}

.sr-only{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;
}

:focus-visible{outline:2px solid var(--signal);outline-offset:3px;border-radius:4px}

.mono{font-family:var(--mono);font-variant-numeric:tabular-nums}

/* a button name on the phone, drawn as a small key */
kbd{
  font-family:var(--sans);font-size:.875em;font-weight:500;line-height:1;
  display:inline-block;padding:4px 8px 5px;margin-inline:1px;
  color:var(--legend);background:var(--cap);
  border:1px solid var(--rule);border-bottom-width:2px;border-radius:6px;
  white-space:nowrap;vertical-align:1px;
}

.textlink{
  color:var(--legend);text-decoration:none;font-weight:500;
  background-image:linear-gradient(var(--signal),var(--signal));
  background-size:100% 2px;background-repeat:no-repeat;background-position:0 100%;
  padding-bottom:3px;transition:color .2s ease;
}
.textlink:hover{color:var(--signal-text)}

/* ---------- masthead ---------- */

.masthead{
  display:flex;align-items:center;justify-content:space-between;
  gap:20px;padding-block:26px 0;
}
.wordmark{font-size:1.0625rem;font-weight:600;letter-spacing:-.015em}
.masthead .textlink{font-size:.9375rem}

/* ---------- hero ---------- */

.hero{
  display:grid;grid-template-columns:minmax(0,1.02fr) minmax(0,1fr);
  gap:clamp(36px,5vw,64px);align-items:center;
  padding-block:clamp(40px,6vw,72px) var(--section);
}
.hero h1{
  font-size:clamp(2.1rem,1.25rem + 2.9vw,3.35rem);
  line-height:1.04;letter-spacing:-.032em;
}
.deck{
  margin-top:20px;max-width:42ch;
  font-size:1.0625rem;color:var(--legend-soft);
}

/* the one filled control on the page: a porcelain keycap */
.keycap{
  position:relative;display:inline-block;padding-bottom:5px;
  text-decoration:none;border-radius:var(--r-key);
}
.keycap__edge{
  position:absolute;left:0;right:0;top:5px;bottom:0;
  background:var(--key-edge);border-radius:var(--r-key);
}
.keycap__face{
  position:relative;display:block;
  background:linear-gradient(180deg,var(--key-hi) 0%,var(--key) 55%,var(--key-lo) 100%);
  color:var(--key-ink);
  border-radius:var(--r-key);
  padding:15px 30px;
  font-size:1.0625rem;font-weight:600;letter-spacing:-.01em;
  box-shadow:inset 0 1px 0 rgba(255,255,255,.22), inset 0 -1px 0 rgba(0,0,0,.14);
  transform:translateY(0);transition:transform 90ms ease-out;
}
.keycap:active .keycap__face{transform:translateY(5px);transition-duration:40ms}
.keycap:focus-visible{outline:none}
.keycap:focus-visible .keycap__face{outline:2px solid var(--signal);outline-offset:4px}

.cta-row{display:flex;flex-wrap:wrap;align-items:center;gap:18px 28px;margin-top:34px}
.cta-note{margin-top:14px;font-size:.875rem;color:var(--legend-faint);max-width:44ch}

/* spec strip: machine data, so it is monospaced */
.spec{
  margin:26px 0 0;display:flex;flex-wrap:wrap;gap:10px 30px;
  padding:14px 18px;background:var(--well);border-radius:var(--r-well);
  box-shadow:inset 0 1px 3px var(--well-shadow);
}
.spec div{display:flex;gap:9px;align-items:baseline;font-size:.8125rem}
.spec dt{color:var(--legend-faint)}
.spec dd{margin:0;font-family:var(--mono);font-variant-numeric:tabular-nums;color:var(--legend)}

/* ---------- the live demo ---------- */

.demo{margin:0;display:flex;flex-direction:column;gap:12px;min-width:0}

.screen{
  background:var(--well);border-radius:var(--r-well);
  box-shadow:inset 0 1px 4px var(--well-shadow);
  overflow:hidden;
}
.screen__bar{
  display:flex;align-items:center;justify-content:space-between;
  padding:9px 14px;border-bottom:1px solid var(--rule-soft);
  font-family:var(--mono);font-size:.75rem;color:var(--legend-faint);
}
.screen__page{
  height:206px;padding:16px 18px;overflow:hidden;
  font-family:var(--mono);font-size:.8125rem;line-height:1.78;
  color:var(--legend);white-space:pre-wrap;word-break:break-word;
}
.caret{
  display:inline-block;width:7px;height:1.05em;margin-left:1px;
  background:var(--signal);vertical-align:-.18em;
}
.caret.blink{animation:blink 1.06s step-end infinite}
@keyframes blink{0%,49%{opacity:1}50%,100%{opacity:0}}

.wire{
  display:grid;grid-template-columns:auto 1fr auto;align-items:center;
  gap:8px 12px;padding:13px 16px;
  background:var(--plate);border:1px solid var(--rule);border-radius:var(--r-plate);
}
.dot{width:9px;height:9px;border-radius:50%;background:var(--signal);box-shadow:0 0 10px var(--signal-glow)}
.dot.pulsing{animation:pulse 1.5s ease-in-out infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.35}}
.dot.idle{background:var(--legend-faint);box-shadow:none}
.wire__state{font-size:.875rem;color:var(--signal-text)}
.wire__state.idle{color:var(--legend-soft)}
.wire__count{font-size:.8125rem;color:var(--legend-soft)}
.bar{
  grid-column:1/-1;height:3px;border-radius:2px;
  background:var(--rule);overflow:hidden;
}
.bar i{display:block;height:100%;background:var(--signal);width:0%;transition:width .18s linear}
.wire__addr{
  grid-column:1/-1;font-size:.75rem;color:var(--legend-faint);
  display:flex;justify-content:space-between;gap:12px;
}

/* ---------- plain sections ---------- */

section{border-top:1px solid var(--rule);padding-block:var(--section)}
.lede{max-width:62ch;margin-top:16px;color:var(--legend-soft)}
h2{font-size:clamp(1.45rem,1.15rem + 1vw,1.95rem)}

.facts{
  display:grid;grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(24px,3vw,40px);margin-top:44px;
}
.fact{border-top:1px solid var(--rule);padding-top:18px}
.fact h3{font-size:1rem;margin-bottom:8px}
.fact p{color:var(--legend-soft);font-size:.9375rem}

/* ============================================================
   The guide: the one lit panel on the page
   ============================================================ */

section.guide{border-top:none;padding-block:clamp(8px,2vw,24px) var(--section)}

.guide__panel{
  display:grid;grid-template-columns:minmax(0,280px) minmax(0,1fr);
  gap:clamp(32px,5vw,72px);
  padding:clamp(24px,4.5vw,60px);
  background:
    radial-gradient(620px 380px at 0% 0%, var(--signal-wash), transparent 72%),
    radial-gradient(520px 420px at 100% 100%, var(--signal-wash), transparent 70%),
    var(--plate);
  border:1px solid var(--rule);
  border-radius:var(--r-plate);
  box-shadow:inset 0 1px 0 var(--plate-edge), 0 40px 90px -50px var(--panel-shadow);
}

.guide__intro{position:sticky;top:28px;align-self:start}

.chip{
  display:inline-flex;align-items:center;gap:9px;
  padding:5px 13px 5px 11px;margin-bottom:20px;border-radius:999px;
  background:var(--signal-soft);color:var(--signal-text);
  font-size:.8125rem;font-weight:500;
}
.chip__dot{
  width:7px;height:7px;border-radius:50%;background:var(--signal);
  box-shadow:0 0 0 3px var(--signal-soft), 0 0 12px var(--signal-glow);
}

.guide h2{
  font-size:clamp(1.85rem,1.2rem + 2vw,2.6rem);
  line-height:1.06;letter-spacing:-.032em;
}
.guide__lede{margin-top:14px;color:var(--legend-body);font-size:1.0625rem;max-width:30ch}

.index{list-style:none;margin:30px 0 0;padding:0;display:flex;flex-direction:column;gap:2px}
.index a{
  display:flex;align-items:center;gap:12px;
  padding:8px 10px;margin-inline:-10px;border-radius:9px;
  text-decoration:none;color:var(--legend-soft);font-size:.9375rem;
  transition:background-color .25s ease,color .25s ease;
}
.index a:hover{color:var(--legend);background:var(--hover)}
.index__n{
  flex:none;width:24px;height:24px;display:grid;place-items:center;
  border:1px solid var(--rule);border-radius:7px;
  font-family:var(--mono);font-size:.75rem;color:var(--legend-faint);
  transition:background-color .25s ease,border-color .25s ease,color .25s ease;
}
.index a.is-on{color:var(--legend);background:var(--signal-soft)}
.index a.is-on .index__n{background:var(--signal);border-color:var(--signal);color:var(--signal-ink)}

/* steps and their rail */
.track{position:relative}
.rail{
  position:absolute;left:22px;top:22px;bottom:80px;width:2px;
  transform:translateX(-1px);background:var(--rule);border-radius:2px;overflow:hidden;
}
.rail i{
  position:absolute;inset:0;background:var(--signal);
  transform-origin:top;transform:scaleY(0);transition:transform .14s linear;
}

.steps{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:44px}
.step{display:grid;grid-template-columns:44px minmax(0,1fr);gap:0 22px;scroll-margin-top:90px}

.step__key{grid-row:1/-1;position:relative;width:44px;height:48px;z-index:1}
.step__key::before{
  content:"";position:absolute;left:0;right:0;top:4px;bottom:0;
  border-radius:11px;background:var(--cap-edge);
}
.step__face{
  position:absolute;left:0;right:0;top:0;height:44px;
  display:grid;place-items:center;border-radius:11px;
  background-color:var(--cap);border:1px solid var(--rule);
  box-shadow:inset 0 1px 0 var(--plate-edge);
  font-family:var(--mono);font-size:.9375rem;font-weight:500;color:var(--signal-text);
  transition:background-color .35s ease,border-color .35s ease,color .35s ease,box-shadow .35s ease,transform .2s ease;
}
.step.is-past .step__face{border-color:var(--signal-line)}
.step.is-lit .step__face{
  background-color:var(--signal);border-color:var(--signal);color:var(--signal-ink);
  box-shadow:0 0 0 4px var(--signal-soft), 0 0 34px var(--signal-glow);
  transform:translateY(2px);
}

.step__body{padding-top:7px;max-width:58ch}
.step__body h3{
  font-size:clamp(1.125rem,1rem + .45vw,1.3125rem);
  letter-spacing:-.022em;margin-bottom:9px;color:var(--legend);
}
.step__body > p{color:var(--legend-body);font-size:1.0625rem;line-height:1.72}

.tip{
  margin-top:14px;display:flex;gap:12px;align-items:baseline;
  padding:12px 15px;border-radius:var(--r-well);
  background:var(--well);box-shadow:inset 0 1px 3px var(--well-shadow);
  font-size:.9375rem;color:var(--legend-soft);line-height:1.6;
}
.tip b{flex:none;font-weight:600;color:var(--signal-text)}

.callouts{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin-top:52px}
.callout{
  padding:20px 22px;border-radius:14px;
  background:var(--chassis);border:1px solid var(--rule);
}
.callout h3{font-size:1rem;margin-bottom:8px}
.callout p{color:var(--legend-body);font-size:.9375rem;line-height:1.7}

/* ---------- after the guide ---------- */

.pairs{
  display:grid;grid-template-columns:repeat(2,minmax(0,1fr));
  gap:clamp(26px,3vw,40px);margin-top:44px;
}
.pair{border-top:1px solid var(--rule);padding-top:18px;max-width:48ch}
.pair h3{font-size:1rem;margin-bottom:8px}
.pair p{color:var(--legend-soft);font-size:.9375rem}

.fix{margin:44px 0 0;display:flex;flex-direction:column;gap:0}
.fix > div{
  display:grid;grid-template-columns:minmax(0,22ch) minmax(0,1fr);
  gap:6px 32px;padding-block:20px;border-top:1px solid var(--rule-soft);
}
.fix > div:first-child{border-top:none;padding-top:0}
.fix dt{font-weight:500}
.fix dd{margin:0;color:var(--legend-soft);font-size:.9375rem;max-width:58ch}

.limits{list-style:none;margin:36px 0 0;padding:0;max-width:62ch;
  display:flex;flex-direction:column;gap:14px}
.limits li{display:grid;grid-template-columns:14px 1fr;gap:12px;
  color:var(--legend-soft);font-size:.9375rem}
.limits li::before{content:"";width:14px;height:1px;background:var(--rule);margin-top:.85em}

.closing{
  display:flex;flex-wrap:wrap;align-items:center;gap:20px 32px;
  margin-top:48px;
}
.closing .cta-note{margin-top:0;max-width:30ch}

footer{
  border-top:1px solid var(--rule);padding-block:30px 44px;
  display:flex;flex-wrap:wrap;gap:8px 28px;align-items:baseline;
  font-size:.875rem;color:var(--legend-faint);
}
footer .mono{font-size:.8125rem}
footer nav{display:flex;flex-wrap:wrap;gap:6px 22px}
footer nav a{color:var(--legend-soft);text-decoration:none}
footer nav a:hover{color:var(--signal-text)}

/* ---------- nav ---------- */

a.wordmark{text-decoration:none}
.nav{display:flex;flex-wrap:wrap;align-items:center;gap:6px 26px}
.nav .textlink{font-size:.9375rem}

.hero .chip{margin-bottom:18px}
.section-link{display:inline-block;margin-top:32px}

/* ---------- tables: measured figures and the comparison ---------- */

.table-wrap{
  margin-top:40px;overflow-x:auto;
  background:var(--plate);border:1px solid var(--rule);border-radius:14px;
}
.table{width:100%;min-width:600px;border-collapse:collapse;font-size:.9375rem;line-height:1.5}
.table th,.table td{padding:13px 18px;text-align:left;vertical-align:top;border-top:1px solid var(--rule-soft)}
.table thead th{border-top:none;background:var(--chassis);font-size:.8125rem;font-weight:500;color:var(--legend-faint)}
.table tbody th{font-weight:500;color:var(--legend)}
.table td{color:var(--legend-soft)}
.table td.us{color:var(--legend);font-weight:500;background:var(--signal-wash)}
.table thead th.us{color:var(--signal-text);background:var(--signal-soft)}
.table .num{font-family:var(--mono);font-variant-numeric:tabular-nums}
.table-note{margin-top:12px;max-width:70ch;font-size:.8125rem;color:var(--legend-faint)}

/* ---------- FAQ ---------- */

.faq{margin-top:36px;max-width:78ch;border-top:1px solid var(--rule)}
.faq details{border-bottom:1px solid var(--rule)}
.faq summary{
  display:flex;align-items:baseline;justify-content:space-between;gap:20px;
  padding-block:18px;cursor:pointer;list-style:none;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary h3{font-size:1.0625rem;font-weight:500;letter-spacing:-.01em;transition:color .2s ease}
.faq summary:hover h3{color:var(--signal-text)}
.faq summary::after{
  content:"+";flex:none;font-family:var(--mono);font-size:1.125rem;line-height:1;
  color:var(--signal-text);transition:transform .2s ease;
}
.faq details[open] summary::after{transform:rotate(45deg)}
.faq details p{max-width:66ch;padding-bottom:20px;color:var(--legend-soft)}

/* ---------- guide pages ---------- */

.crumbs{padding-block:clamp(36px,5vw,56px) 0;font-size:.875rem;color:var(--legend-faint)}
.crumbs ol{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:6px}
.crumbs li + li::before{content:"/";margin-right:6px;color:var(--legend-faint)}
.crumbs a{color:var(--legend-soft);text-decoration:none}
.crumbs a:hover{color:var(--signal-text)}

.article-head{padding-block:20px clamp(44px,6vw,72px)}
.article-head h1{
  max-width:22ch;
  font-size:clamp(2rem,1.2rem + 2.6vw,3.1rem);
  line-height:1.06;letter-spacing:-.032em;
}
.article-head .deck{max-width:60ch}

.article section{padding-block:clamp(44px,5.5vw,72px)}
.prose{max-width:68ch}
.prose > p,.prose > ul,.prose > ol{margin-top:16px;color:var(--legend-body);font-size:1.0625rem;line-height:1.72}
.prose ul,.prose ol{padding-left:1.25em}
.prose li{margin-top:8px}
.prose li::marker{color:var(--signal)}
.prose h3{margin-top:30px;font-size:1.125rem}
.prose .textlink{font-weight:500}

@media (max-width:980px){
  .guide__panel{grid-template-columns:minmax(0,1fr);gap:36px}
  .guide__intro{position:static}
  .guide__lede{max-width:46ch}
  .index{display:none}
  .callouts{grid-template-columns:minmax(0,1fr)}
}
@media (max-width:900px){
  .hero{grid-template-columns:minmax(0,1fr);gap:44px}
  .deck{max-width:52ch}
  .facts{grid-template-columns:minmax(0,1fr);gap:26px}
  .pairs{grid-template-columns:minmax(0,1fr)}
}
@media (max-width:560px){
  .masthead{flex-wrap:wrap}
  .nav{gap:6px 20px}
  .table th,.table td{padding:11px 14px}
  .screen__page{height:240px;font-size:.78125rem}
  .fix > div{grid-template-columns:minmax(0,1fr);gap:6px}
  .keycap{display:block}
  .keycap__face{text-align:center;padding-inline:22px}
  .cta-row{gap:16px}
  .guide__panel{padding:22px 18px 28px;border-radius:16px}
  .step{grid-template-columns:40px minmax(0,1fr);gap:0 16px}
  .step__key{width:40px;height:44px}
  .step__face{height:40px}
  .rail{left:20px}
  .step__body > p{font-size:1rem}
  .tip{flex-direction:column;gap:2px}
}

@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
}
@media (prefers-reduced-motion: no-preference){
  html{scroll-behavior:smooth}
}