/*
 * statuscodechecker.org, direction "Forwarding Office".
 * A redirect is mail forwarding: each hop is a gummed forwarding label pasted
 * over the last address and stamped with its code; the final answer is the
 * delivery postmark. Light only (a desk in daytime office light).
 * Shapes are label stock, rubber stamps and type. Flat inks, no boxes.
 */

/* ── fonts (self-hosted, OFL; licences in fonts/) ───────────────────── */

@font-face {
  font-family: "Archivo Variable";
  font-style: normal;
  font-display: swap;
  font-weight: 100 900;
  font-stretch: 62% 125%;
  src: url("../fonts/archivo-latin-wdth-normal.woff2") format("woff2-variations"),
       url("../fonts/archivo-latin-wdth-normal.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

@font-face {
  font-family: "Courier Prime";
  font-style: normal;
  font-display: swap;
  font-weight: 400;
  src: url("../fonts/courier-prime-latin-400-normal.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* ── tokens ─────────────────────────────────────────────────────────── */

:root {
  color-scheme: light;

  /* stocks */
  --kraft: #c89f6e;              /* the envelope: carbon on it is 7.2:1 */
  --kraft-rule: #8c6a43;
  --paper: #ffffff;              /* address labels and the reading sheet */
  --paper-rule: #dacdb9;

  /* inks */
  --carbon: #1a1a1a;
  --carbon-soft: #3b3b3b;
  --ink-brown: #3f2c1a;          /* secondary text on kraft: 5.4:1 */
  --ink-faded: #6e5a44;          /* secondary text on paper: 6.6:1 */
  --label-yellow: #ffd21f;       /* 3xx forwarding label */
  --stamp-red: #d2232a;          /* 4xx, on paper only: 5.2:1 */
  --delivered-green: #1e7a3e;    /* 2xx postmark, on paper only: 5.4:1 */
  --route-violet: #5b2a86;       /* reserved: the forwarding path and focus */

  /* type */
  --font-office: "Archivo Variable", "Archivo", "Arial Narrow", sans-serif;
  --font-typed: "Courier Prime", "Courier New", monospace;
  --width-condensed: 62%;
  --width-semi: 80%;
  --width-normal: 100%;

  --text-xs: 0.8125rem;
  --text-sm: 0.9375rem;
  --text-base: 1.0625rem;
  --text-md: 1.1875rem;
  --text-lg: 1.375rem;
  --text-xl: 1.75rem;
  --text-code: 2rem;
  --text-h2: clamp(2.25rem, 1rem + 3.4vw, 4.25rem);
  --text-display: clamp(3.25rem, 1.5rem + 5.5vw, 6rem);

  /* space */
  --space-2xs: 0.25rem;
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2.5rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;
  --section-gap: clamp(3.5rem, 7vw, 6rem);
  --topic-gap: clamp(2.75rem, 5.5vw, 4.5rem);

  /* page */
  --page-max: 82.5rem;
  --gutter: clamp(1rem, 4vw, 3.5rem);
  --header-h: 4.5rem;
  --flap: clamp(1.5rem, 4vw, 3.5rem);
  --label-inset: 1.25rem;

  /* rules and stamp frames */
  --focus-ring: 3px;
  --rule-thin: 1px;
  --rule-heavy: 2px;
  --frame-double: 5px;
  --frame-double-sm: 4px;
  --frame-bar: 7px;
  --frame-bar-sm: 5px;

  /* the result: label stack and forwarding path */
  --route-gutter: 1.75rem;
  --route-x: 0.5rem;
  --route-w: 3px;
  --route-node: 9px;
  --label-pad: 1rem;
  --stamp-slot: 3.75rem;
  --label-overlap: 0.75rem;
  --label-pad-under: 1.75rem;    /* label pad + the overlap the next label covers */
  --label-shift: 1.5rem;
  --tab-w: 1.75rem;
  --tab-gap: 3px;
  --tab-shoulder: 0.375rem;

  /* motion */
  --ease-settle: cubic-bezier(0.16, 1, 0.3, 1);
  --paste-ms: 220ms;
  --paste-stagger: 70ms;
  --press-ms: 170ms;
  --fade-ms: 160ms;

  /* drawn marks (masks, filled with an ink) */
  --mark-caution: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2.25' stroke-linejoin='miter'%3E%3Cpath d='M12 2.5 22.5 21h-21z'/%3E%3Cpath d='M12 9v6M12 16.75v2'/%3E%3C/svg%3E");
  --mark-node: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 9 9'%3E%3Crect width='9' height='9'/%3E%3C/svg%3E");
  --mark-arrowhead: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 7 9'%3E%3Cpath d='M0 0 7 4.5 0 9z'/%3E%3C/svg%3E");
  --mark-rule: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1 1' preserveAspectRatio='none'%3E%3Crect width='1' height='1'/%3E%3C/svg%3E");
}

/* ── base ───────────────────────────────────────────────────────────── */

*,
*::before,
*::after {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  background: var(--kraft);
  scrollbar-color: var(--carbon) var(--kraft);
}

body {
  margin: 0;
  background: var(--kraft);
  color: var(--carbon);
  font-family: var(--font-office);
  font-stretch: var(--width-normal);
  font-size: var(--text-base);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: var(--label-yellow);
  color: var(--carbon);
}

a {
  color: inherit;
  text-decoration-thickness: 2px;
  text-underline-offset: 0.22em;
}

a:hover {
  text-decoration-thickness: 3px;
}

:focus-visible {
  outline: var(--focus-ring) solid var(--route-violet);
  outline-offset: 3px;
}

button,
input {
  font: inherit;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

.wrap {
  width: min(100% - 2 * var(--gutter), var(--page-max));
  margin-inline: auto;
}

/* ── header strip on kraft ──────────────────────────────────────────── */

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  min-height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  font-weight: 800;
  font-stretch: var(--width-condensed);
  font-size: var(--text-lg);
  line-height: 1;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  text-decoration: none;
}

.brand-mark {
  display: block;
  flex: none;
  width: 2rem;
  height: 2rem;
}

.brand-mark .mark-paper { fill: var(--paper); }
.brand-mark .mark-label { fill: var(--label-yellow); }
.brand-mark .mark-ink { stroke: var(--carbon); }

.site-nav a {
  font-weight: 700;
  font-stretch: var(--width-condensed);
  font-size: var(--text-md);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* ── first viewport: the envelope ───────────────────────────────────── */

.hero {
  display: grid;
  grid-template-columns: minmax(0, 11fr) minmax(0, 9fr);
  grid-template-rows: auto auto auto 1fr;
  column-gap: clamp(2.5rem, 5vw, 4.5rem);
  align-items: start;
  min-height: calc(100svh - var(--header-h));
  padding-block: clamp(2rem, 4.5vw, 3.5rem) clamp(3.5rem, 6vw, 5rem);
}

.hero > h1 {
  grid-column: 1;
  margin: 0;
  font-weight: 850;
  font-stretch: var(--width-condensed);
  font-size: var(--text-display);
  line-height: 0.88;
  letter-spacing: -0.01em;
  word-spacing: 0.08em;
  text-transform: uppercase;
  text-wrap: balance;
}

.lede {
  grid-column: 1;
  max-width: 40ch;
  margin: var(--space-lg) 0 0;
  font-size: 1.25rem;
  line-height: 1.5;
}

.hero > .check {
  grid-column: 1;
  margin-top: var(--space-xl);
}

.hero > .result {
  grid-column: 2;
  grid-row: 1 / -1;
}

/* ── the form: an address label with a postmark button ──────────────── */

.check {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  max-width: 40rem;
}

.check::before {
  content: "";
  grid-column: 1;
  grid-row: 1 / 3;
  background: var(--paper);
}

.check label {
  grid-column: 1;
  grid-row: 1;
  padding: var(--space-md) var(--label-inset) 0;
  color: var(--ink-faded);
  font-weight: 700;
  font-stretch: var(--width-semi);
  font-size: var(--text-xs);
  line-height: 1.2;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.check-row {
  display: contents;
}

.check-row input {
  grid-column: 1;
  grid-row: 2;
  min-width: 0;
  margin: 0.375rem var(--label-inset) 1.125rem;
  padding: 0.25rem 0 0.375rem;
  border: 0;
  border-bottom: var(--rule-thin) solid var(--carbon);
  border-radius: 0;
  background: var(--paper);
  color: var(--carbon);
  caret-color: var(--carbon);
  font-family: var(--font-typed);
  font-size: 1.25rem;
  line-height: 1.3;
  appearance: none;
}

.check-row input::placeholder {
  color: var(--ink-faded);
  opacity: 1;
}

.check-row input:focus-visible {
  outline-offset: 5px;
}

.button {
  margin: 0;
  border: 0;
  border-radius: 0;
  cursor: pointer;
  appearance: none;
}

.check .button {
  grid-column: 2;
  grid-row: 1 / 3;
  display: grid;
  place-items: center;
  padding: 0 clamp(1.25rem, 2.5vw, 2rem);
  background: var(--carbon);
  color: var(--paper);
  font-weight: 850;
  font-stretch: var(--width-condensed);
  font-size: var(--text-xl);
  line-height: 1;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
}

.check .button:hover:not(:disabled) {
  background: var(--carbon-soft);
}

.check .button:disabled {
  background: var(--ink-faded);
  cursor: not-allowed;
}

.captcha {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
}

.alert {
  position: relative;
  grid-column: 1 / -1;
  margin: var(--space-xs) 0 0;
  padding: var(--space-sm) var(--label-inset) var(--space-sm) 3rem;
  background: var(--paper);
  color: var(--stamp-red);
  font-weight: 650;
  line-height: 1.4;
}

.alert::before {
  content: "";
  position: absolute;
  top: 0.85rem;
  left: var(--label-inset);
  width: 1.125rem;
  height: 1.125rem;
  background: var(--stamp-red);
  -webkit-mask: var(--mark-caution) center / contain no-repeat;
  mask: var(--mark-caution) center / contain no-repeat;
}

.allowance {
  grid-column: 1 / -1;
  margin: var(--space-sm) 0 0;
  color: var(--ink-brown);
  font-weight: 500;
  font-size: var(--text-sm);
}

.allowance:empty {
  display: none;
}

/* ── the result: a stack of mail ────────────────────────────────────── */

.result {
  position: relative;
  transition: opacity var(--fade-ms) ease-out;
}

.result[aria-busy="true"] {
  opacity: 0.5;
}

.result > :is(.result-head, .note, .facts, .chips, .result-foot) {
  margin-inline: var(--route-gutter) var(--label-shift);
}

.result-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-sm) var(--space-md);
}

.result-reason {
  font-weight: 800;
  font-stretch: var(--width-condensed);
  font-size: var(--text-xl);
  line-height: 1;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.example-tag {
  margin-left: auto;
  padding: 0.375rem 0.5rem 0.3rem 0.625rem;
  border: var(--frame-double-sm) double var(--carbon);
  font-weight: 800;
  font-stretch: var(--width-condensed);
  font-size: var(--text-xs);
  line-height: 1;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  rotate: -0.8deg;
}

.result-summary {
  flex-basis: 100%;
  margin: var(--space-2xs) 0 0;
  font-weight: 500;
}

/* Stamps. The element is the stock the stamp lands on; ::before is the inked
   frame; the text is the code. Every class keeps the same shape everywhere. */

.result-code,
.code {
  position: relative;
  isolation: isolate;
  display: inline-grid;
  flex: none;
  place-items: center;
  color: var(--carbon);
  font-weight: 900;
  font-stretch: var(--width-condensed);
  line-height: 1;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums lining-nums;
}

.result-code::before,
.code::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
}

.c-2xx, .code-2xx { color: var(--delivered-green); }
.c-4xx, .code-4xx { color: var(--stamp-red); }
.c-3xx, .code-3xx { background: var(--label-yellow); }

.c-2xx::before,
.code-2xx::before {
  border: var(--frame-double) double var(--delivered-green);
  border-radius: 50%;
}

.c-3xx::before,
.code-3xx::before {
  border: var(--frame-double) double var(--carbon);
}

.c-4xx::before,
.code-4xx::before {
  border: var(--frame-double) double var(--stamp-red);
}

.c-5xx::before,
.code-5xx::before {
  border-block: var(--frame-bar) solid var(--carbon);
}

.c-none::before {
  border: var(--rule-heavy) solid var(--carbon);
}

.c-none::after {
  content: "";
  position: absolute;
  inset: 0.45rem;
  z-index: -1;
  background: var(--carbon);
  clip-path: polygon(0 calc(100% - 3px), calc(100% - 3px) 0, 100% 0, 100% 3px, 3px 100%, 0 100%);
}

/* the head's mark sits on its own scrap of label stock */
.result-code {
  min-width: 5.25rem;
  height: 3.75rem;
  padding: 0 1rem;
  background-color: var(--paper);
  font-size: var(--text-code);
}

.result-code.c-3xx { background-color: var(--label-yellow); }

.result-code::before { inset: 0.45rem; }
.result-code.c-5xx::before { inset: 0.6rem 0.45rem; }

.result-code.c-2xx {
  width: 4.5rem;
  height: 4.5rem;
  min-width: 0;
  padding: 0;
  font-size: 1.625rem;
}

.result-code.c-2xx::before { inset: 0.3rem; }

/* the hops: forwarding labels pasted one over the other */

.trace {
  margin: var(--space-lg) 0 0;
  padding: 0 0 0 var(--route-gutter);
  list-style: none;
}

.hop {
  --shift: 0rem;
  --tilt: -0.5deg;
  --i: 0;
  position: relative;
  display: grid;
  grid-template-columns: var(--stamp-slot) minmax(0, 1fr);
  row-gap: var(--space-xs);
  width: calc(100% - var(--label-shift));
  margin-left: var(--shift);
  padding: var(--label-pad) var(--label-pad) var(--label-pad-under);
  outline: var(--rule-heavy) solid var(--kraft);
  background: var(--paper);
  rotate: var(--tilt);
  transform-origin: 30% 50%;
  transition: opacity var(--fade-ms) ease-out;
}

.hop:has(.code-3xx) {
  background: var(--label-yellow);
}

.hop + .hop {
  margin-top: calc(-1 * var(--label-overlap));
}

.hop:nth-child(even) {
  --shift: var(--label-shift);
  --tilt: 0.6deg;
}

.hop:last-child {
  padding-bottom: var(--label-pad);
}

.hop:last-child:nth-child(odd) { --tilt: -0.3deg; }

.hop:nth-child(2) { --i: 1; }
.hop:nth-child(3) { --i: 2; }
.hop:nth-child(4) { --i: 3; }
.hop:nth-child(5) { --i: 4; }
.hop:nth-child(6) { --i: 5; }
.hop:nth-child(7) { --i: 6; }
.hop:nth-child(8) { --i: 7; }
.hop:nth-child(9) { --i: 8; }
.hop:nth-child(10) { --i: 9; }
.hop:nth-child(n + 11) { --i: 10; }

.hop .code {
  grid-column: 1;
  grid-row: 1;
  width: var(--stamp-slot);
  height: var(--stamp-slot);
  font-size: 1.5rem;
}

.hop .code-3xx { background: transparent; }
.hop .code-3xx::before,
.hop .code-4xx::before { inset: 0.5rem 0; }
.hop .code-5xx::before { inset: 0.6rem 0; }
.hop .code-2xx { font-size: 1.375rem; }

.hop-url {
  grid-column: 1 / -1;
  grid-row: 2;
  font-family: var(--font-typed);
  font-size: var(--text-sm);
  line-height: 1.35;
  overflow-wrap: anywhere;
}

.hop-reason {
  position: absolute;
  top: var(--label-pad);
  right: var(--label-pad);
  left: calc(var(--label-pad) + var(--stamp-slot) + var(--space-md));
  display: flex;
  align-items: center;
  height: var(--stamp-slot);
  font-family: var(--font-office);
  font-weight: 800;
  font-stretch: var(--width-condensed);
  font-size: var(--text-lg);
  line-height: 1.05;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

/* the live forwarding path: a node on the route and an arrow into each stamp */
.hop::before {
  content: "";
  position: absolute;
  top: calc(var(--label-pad) + var(--stamp-slot) / 2 - var(--route-node) / 2);
  left: calc(var(--route-x) - var(--route-gutter) - var(--shift) - var(--route-node) / 2);
  width: calc(var(--route-gutter) + var(--shift) - var(--route-x) + var(--route-node) / 2 + var(--label-pad) - 3px);
  height: var(--route-node);
  background: var(--route-violet);
  -webkit-mask:
    var(--mark-node) left center / var(--route-node) var(--route-node) no-repeat,
    var(--mark-arrowhead) right center / 7px var(--route-node) no-repeat,
    var(--mark-rule) center / 100% var(--route-w) no-repeat;
  mask:
    var(--mark-node) left center / var(--route-node) var(--route-node) no-repeat,
    var(--mark-arrowhead) right center / 7px var(--route-node) no-repeat,
    var(--mark-rule) center / 100% var(--route-w) no-repeat;
}

.hop:not(:last-child)::after {
  content: "";
  position: absolute;
  top: calc(var(--label-pad) + var(--stamp-slot) / 2);
  bottom: calc(var(--label-overlap) - var(--label-pad) - var(--stamp-slot) / 2);
  left: calc(var(--route-x) - var(--route-gutter) - var(--shift) - var(--route-w) / 2);
  width: var(--route-w);
  background: var(--route-violet);
}

/* one leg at a time */
.trace:has(.hop:hover) .hop:not(:hover) {
  opacity: 0.45;
}

/* a caution slip pasted on */
.note {
  position: relative;
  margin-block: var(--space-md) 0;
  padding: var(--space-sm) var(--space-md) var(--space-sm) 2.75rem;
  background: var(--paper);
  font-weight: 650;
  line-height: 1.4;
}

.note::before {
  content: "";
  position: absolute;
  top: 0.85rem;
  left: var(--space-md);
  width: 1.125rem;
  height: 1.125rem;
  background: var(--carbon);
  -webkit-mask: var(--mark-caution) center / contain no-repeat;
  mask: var(--mark-caution) center / contain no-repeat;
}

/* the delivery receipt */
.facts {
  display: grid;
  grid-template-columns: max-content minmax(0, 1fr);
  column-gap: var(--space-lg);
  margin-block: var(--space-lg) 0;
  padding: var(--space-2xs) var(--label-inset);
  background: var(--paper);
}

.facts dt,
.facts dd {
  padding: 0.625rem 0;
  border-top: var(--rule-thin) solid var(--paper-rule);
  line-height: 1.5rem;
}

.facts dt:first-of-type,
.facts dt:first-of-type + dd {
  border-top: 0;
}

.facts dt {
  color: var(--ink-faded);
  font-weight: 700;
  font-stretch: var(--width-semi);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.facts dd {
  margin: 0;
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

.facts dd.mono {
  font-family: var(--font-typed);
  font-size: var(--text-sm);
  overflow-wrap: anywhere;
}

/* noindex and nofollow: two stamped instructions */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm) var(--space-xl);
  margin-block: var(--space-lg) 0;
  padding: 0;
  list-style: none;
}

.chip {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-xs) var(--space-sm);
}

.chip strong {
  padding: 0.5rem 0.625rem 0.45rem;
  border: var(--frame-double-sm) double var(--carbon);
  font-weight: 800;
  font-stretch: var(--width-condensed);
  font-size: var(--text-base);
  line-height: 1;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
}

.chip span {
  color: var(--ink-brown);
  font-weight: 500;
  font-size: var(--text-sm);
}

.chip-set strong {
  border-color: var(--stamp-red);
  background: var(--stamp-red);
  color: var(--paper);
}

.chip:not(.chip-set, .chip-clear) strong {
  padding: 0.625rem 0.75rem 0.575rem;
  border: var(--rule-heavy) dashed var(--carbon);
}

.result-foot {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-xs) var(--space-lg);
  margin-block: var(--space-lg) 0;
}

.button-quiet {
  padding: var(--space-2xs) 0;
  background: transparent;
  color: var(--carbon);
  font-weight: 800;
  font-stretch: var(--width-condensed);
  font-size: var(--text-md);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 0.28em;
}

.button-quiet:hover {
  text-decoration-thickness: 4px;
}

.result-foot p {
  margin: 0;
  color: var(--ink-brown);
  font-size: var(--text-sm);
}

/* ── the reading sheet ──────────────────────────────────────────────── */

/* Each topic is its own grid, so its title stays pinned only while that
   topic is on screen. Topics alternate sides: title left, then title right. */

.topics {
  padding-block: clamp(4rem, 9vw, 7.5rem) calc(clamp(4.5rem, 9vw, 8rem) + var(--flap));
  background: var(--paper);
}

.topic {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 46rem);
  column-gap: clamp(2.5rem, 6vw, 6rem);
  align-items: start;
}

.topic + .topic {
  margin-top: var(--topic-gap);
  padding-top: var(--topic-gap);
  border-top: var(--rule-thin) solid var(--paper-rule);
}

.topic > h2 {
  position: sticky;
  top: var(--space-xl);
  grid-column: 1;
  grid-row: 1;
  max-width: 12ch;
  margin: 0;
  font-weight: 850;
  font-stretch: var(--width-condensed);
  font-size: var(--text-h2);
  line-height: 0.92;
  letter-spacing: -0.005em;
  word-spacing: 0.06em;
  text-transform: uppercase;
  text-wrap: balance;
}

.topic-body {
  grid-column: 2;
  grid-row: 1;
  min-width: 0;
}

.topic:nth-child(even) {
  grid-template-columns: minmax(0, 46rem) minmax(0, 1fr);
}

.topic:nth-child(even) > h2 {
  grid-column: 2;
  justify-self: end;
  text-align: right;
}

.topic:nth-child(even) > .topic-body {
  grid-column: 1;
}

.reading p {
  max-width: 62ch;
  margin: 1.25rem 0 0;
  font-size: var(--text-md);
  line-height: 1.65;
}

.topic-body > :first-child {
  margin-top: 0;
}

.reading strong {
  font-weight: 700;
}

.reading code {
  font-family: var(--font-typed);
  font-size: 0.95em;
}

/* the status codes: a sorting rack with class divider tabs */

.table-scroll {
  overflow-x: auto;
  scrollbar-color: var(--carbon) var(--paper);
  scrollbar-width: thin;
}

.codes {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  font-size: var(--text-base);
  font-variant-numeric: tabular-nums;
}

.codes thead th,
.codes .rack-corner {
  padding: 0 var(--space-md) var(--space-sm);
  border-bottom: var(--rule-heavy) solid var(--carbon);
  color: var(--ink-faded);
  font-weight: 700;
  font-stretch: var(--width-semi);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-align: left;
  text-transform: uppercase;
  vertical-align: bottom;
}

.codes .rack-corner {
  width: var(--tab-w);
  padding: 0;
}

.codes tbody th[scope="row"],
.codes td {
  padding: var(--space-sm) var(--space-md);
  border-bottom: var(--rule-thin) solid var(--paper-rule);
  font-weight: 400;
  line-height: 1.5;
  text-align: left;
  vertical-align: middle;
}

.codes tbody th[scope="row"] {
  width: 1%;
  white-space: nowrap;
}

.codes td.name {
  width: 12rem;
  font-weight: 650;
}

/* a divider tab at the top of each class group, carrying the class name;
   the group below it is marked only by its stamps */
.codes .rack-tab {
  width: var(--tab-w);
  padding: var(--tab-gap) 0 0;
  vertical-align: top;
}

.rack-label {
  display: block;
  width: var(--tab-w);
  padding: 0.875rem 0;
  background: var(--tab-ink);
  color: var(--tab-text);
  font-weight: 850;
  font-stretch: var(--width-condensed);
  font-size: var(--text-sm);
  line-height: 1;
  letter-spacing: 0.08em;
  text-align: center;
  text-transform: uppercase;
  writing-mode: vertical-rl;
  rotate: 180deg;
  clip-path: polygon(0 0, 100% var(--tab-shoulder), 100% calc(100% - var(--tab-shoulder)), 0 100%);
}

.rack-2xx { --tab-ink: var(--delivered-green); --tab-text: var(--paper); }
.rack-3xx { --tab-ink: var(--label-yellow); --tab-text: var(--carbon); }
.rack-4xx { --tab-ink: var(--stamp-red); --tab-text: var(--paper); }
.rack-5xx { --tab-ink: var(--carbon); --tab-text: var(--paper); }

.codes .code {
  min-width: 3.25rem;
  height: 2.25rem;
  padding: 0 0.5rem;
  font-size: var(--text-base);
}

.codes .code::before {
  border-width: var(--frame-double-sm);
}

.codes .code-5xx::before {
  inset: 0.2rem 0;
  border-width: var(--frame-bar-sm) 0;
}

.codes .code-2xx {
  width: 2.75rem;
  height: 2.75rem;
  min-width: 0;
  padding: 0;
}

/* questions: change-of-address card entries */

.faq {
  border-top: var(--rule-heavy) solid var(--carbon);
}

.faq details {
  border-bottom: var(--rule-thin) solid var(--paper-rule);
}

.faq summary {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 1.5rem;
  align-items: center;
  gap: var(--space-md);
  padding: 1.125rem 0;
  font-weight: 650;
  font-size: var(--text-md);
  line-height: 1.35;
  list-style: none;
  cursor: pointer;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::after {
  content: "";
  width: 1.5rem;
  height: 1.5rem;
  background: var(--carbon);
  -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2.5' stroke-linecap='square'%3E%3Cpath d='M5 3.5v8.5a4 4 0 0 0 4 4h10'/%3E%3Cpath d='M15 11.5l4.5 4.5-4.5 4.5'/%3E%3C/svg%3E") center / contain no-repeat;
  mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2.5' stroke-linecap='square'%3E%3Cpath d='M5 3.5v8.5a4 4 0 0 0 4 4h10'/%3E%3Cpath d='M15 11.5l4.5 4.5-4.5 4.5'/%3E%3C/svg%3E") center / contain no-repeat;
}

.faq details[open] > summary::after {
  rotate: 90deg;
}

.faq summary:hover {
  text-decoration: underline;
  text-decoration-thickness: 1.5px;
  text-underline-offset: 0.25em;
}

.faq details > p {
  max-width: 64ch;
  margin: 0 0 var(--space-lg);
  padding-right: var(--space-xl);
}

/* ── footer: the envelope's back flap ───────────────────────────────── */

.site-footer {
  position: relative;
  margin-top: calc(-1 * var(--flap));
  padding: calc(var(--flap) + var(--space-xl)) 0 var(--space-2xl);
  background: var(--kraft);
  clip-path: polygon(0 var(--flap), 50% 0, 100% var(--flap), 100% 100%, 0 100%);
}

.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-sm) var(--space-xl);
}

.footer-name {
  margin-right: auto;
  font-weight: 850;
  font-stretch: var(--width-condensed);
  font-size: var(--text-xl);
  line-height: 1;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.site-footer a {
  font-weight: 600;
}

.site-footer .wrap > span:last-child {
  font-family: var(--font-typed);
}

/* ── inner pages: the test index, privacy, 404 ──────────────────────── */

.page-head {
  padding-block: clamp(2rem, 5vw, 3.5rem) clamp(3rem, 6vw, 4.5rem);
}

.page-head h1 {
  margin: 0;
  font-weight: 850;
  font-stretch: var(--width-condensed);
  font-size: var(--text-h2);
  line-height: 0.92;
  letter-spacing: -0.005em;
  word-spacing: 0.06em;
  text-transform: uppercase;
  text-wrap: balance;
}

.page-head .lede {
  max-width: 52ch;
}

.page-sheet {
  padding-block: clamp(3rem, 7vw, 5.5rem) calc(clamp(4rem, 8vw, 6.5rem) + var(--flap));
  background: var(--paper);
}

.page-sheet .reading {
  max-width: 46rem;
}

.page-sheet .reading > :first-child {
  margin-top: 0;
}

.page-sheet .reading h2 {
  margin: var(--space-2xl) 0 0;
  font-weight: 850;
  font-stretch: var(--width-condensed);
  font-size: var(--text-xl);
  line-height: 1;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.page-sheet .reading h2 + p {
  margin-top: var(--space-sm);
}

/* the test index: one forwarding label per test page */

.tests {
  margin: 0;
  padding: 0;
  border-top: var(--rule-heavy) solid var(--carbon);
  list-style: none;
}

.tests li {
  display: grid;
  grid-template-columns: var(--stamp-slot) minmax(0, 1fr) auto;
  align-items: center;
  gap: var(--space-md) var(--space-lg);
  padding: var(--space-md) 0;
  border-bottom: var(--rule-thin) solid var(--paper-rule);
}

.tests .code {
  justify-self: start;
  min-width: 3.25rem;
  height: 2.25rem;
  padding: 0 0.5rem;
  font-size: var(--text-base);
}

.tests .code::before {
  border-width: var(--frame-double-sm);
}

.tests .code-5xx::before {
  inset: 0.2rem 0;
  border-width: var(--frame-bar-sm) 0;
}

.tests .code-2xx {
  width: 2.75rem;
  height: 2.75rem;
  min-width: 0;
  padding: 0;
}

.test-path {
  display: block;
  width: fit-content;
  font-family: var(--font-typed);
  font-size: var(--text-md);
  overflow-wrap: anywhere;
}

.test-expect {
  display: block;
  margin-top: var(--space-2xs);
  color: var(--ink-faded);
  font-size: var(--text-sm);
}

.tests + .reading {
  margin-top: var(--space-2xl);
}

.button-link {
  display: inline-grid;
  place-items: center;
  min-height: 2.75rem;
  padding: 0 var(--space-md);
  background: var(--carbon);
  color: var(--paper);
  font-weight: 800;
  font-stretch: var(--width-condensed);
  font-size: var(--text-md);
  line-height: 1;
  letter-spacing: 0.04em;
  text-decoration: none;
  text-transform: uppercase;
  white-space: nowrap;
}

.button-link:hover {
  background: var(--carbon-soft);
}

.page-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin: var(--space-xl) 0 0;
}

/* the 404 page and the test fixtures: one large stamp */

.fixture-code {
  position: relative;
  isolation: isolate;
  display: inline-grid;
  place-items: center;
  min-width: 8.5rem;
  height: 5.5rem;
  margin: 0 0 var(--space-lg);
  padding: 0 1.5rem;
  background: var(--paper);
  color: var(--carbon);
  font-weight: 900;
  font-stretch: var(--width-condensed);
  font-size: 3rem;
  line-height: 1;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums lining-nums;
  rotate: -1.5deg;
}

.fixture-code::before {
  content: "";
  position: absolute;
  inset: 0.55rem;
  z-index: -1;
  border: var(--frame-double) double currentcolor;
}

.fixture-code.c-4xx {
  color: var(--stamp-red);
}

.fixture {
  max-width: 40rem;
  margin: clamp(2.5rem, 8vw, 5rem) auto;
  padding: 0 var(--gutter);
}

.fixture h1 {
  margin: 0;
  font-weight: 850;
  font-stretch: var(--width-condensed);
  font-size: var(--text-h2);
  line-height: 0.92;
  text-transform: uppercase;
}

.fixture p:not(.fixture-code) {
  max-width: 52ch;
  font-size: var(--text-md);
}

.fixture a {
  margin-right: var(--space-lg);
  font-weight: 700;
}

/* ── motion: labels pasted in order, then the postmark ─────────────── */

@keyframes paste {
  from { scale: 1.06; }
  to { scale: 1; }
}

@keyframes press {
  from { scale: 1.15; }
  to { scale: 1; }
}

@media (prefers-reduced-motion: no-preference) {
  .result.is-fresh .hop {
    animation: paste var(--paste-ms) var(--ease-settle) both;
    animation-delay: calc(var(--i) * var(--paste-stagger));
  }

  .result.is-fresh .hop:last-child .code {
    animation: press var(--press-ms) var(--ease-settle) both;
    animation-delay: calc(var(--i) * var(--paste-stagger) + var(--paste-ms));
  }

  .result.is-fresh:not(:has(.trace)) .result-code {
    animation: press var(--press-ms) var(--ease-settle) both;
  }

  .faq summary::after {
    transition: rotate 200ms var(--ease-settle);
  }
}

@media (prefers-reduced-motion: reduce) {
  .result,
  .hop {
    transition: none;
  }
}

/* ── narrower screens ───────────────────────────────────────────────── */

@media (max-width: 62rem) {
  .hero {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: none;
    min-height: 0;
  }

  .hero > .result {
    grid-column: 1;
    grid-row: auto;
    margin-top: var(--space-2xl);
  }

  .topic,
  .topic:nth-child(even) {
    grid-template-columns: minmax(0, 1fr);
  }

  .topic > h2,
  .topic:nth-child(even) > h2 {
    position: static;
    grid-column: 1;
    grid-row: 1;
    justify-self: start;
    max-width: 18ch;
    text-align: left;
  }

  .topic > .topic-body,
  .topic:nth-child(even) > .topic-body {
    grid-column: 1;
    grid-row: 2;
    margin-top: var(--space-lg);
  }
}

@media (max-width: 35rem) {
  :root {
    --route-gutter: 1.25rem;
    --route-x: 0.3rem;
    --label-shift: 0.75rem;
    --label-pad: 0.875rem;
    --label-pad-under: 1.625rem;
    --stamp-slot: 3.5rem;
    --label-inset: 1rem;
  }

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

  .check .button {
    grid-column: 1;
    grid-row: 3;
    padding: var(--space-md);
  }

  .check-row input {
    font-size: 1.125rem;
  }

  .hop-reason {
    font-size: var(--text-md);
  }

  .result-reason {
    font-size: var(--text-lg);
  }

  .codes {
    font-size: var(--text-sm);
  }

  .codes thead th {
    padding-inline: 0.5rem;
  }

  .codes tbody th[scope="row"],
  .codes td {
    padding: 0.625rem 0.5rem;
    line-height: 1.4;
  }

  .codes tbody th[scope="row"] {
    padding-left: 0.625rem;
  }

  .codes td.name {
    width: auto;
  }

  .codes .code {
    min-width: 2.875rem;
    height: 2rem;
    padding: 0 0.375rem;
    font-size: var(--text-sm);
  }

  .codes .code-2xx {
    width: 2.5rem;
    height: 2.5rem;
  }

  .hop-url,
  .facts dd.mono {
    font-size: 0.875rem;
  }

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

  .facts dt {
    padding-bottom: 0;
  }

  .facts dd {
    padding-top: 0.125rem;
    border-top: 0;
  }

  .faq details > p {
    padding-right: 0;
  }

  .tests li {
    grid-template-columns: var(--stamp-slot) minmax(0, 1fr);
  }

  .tests .button-link {
    grid-column: 2;
    justify-self: start;
  }

  .fixture-code {
    min-width: 7rem;
    height: 4.75rem;
    font-size: 2.5rem;
  }
}