/* Archivo (variable: weight 100–900, width 62–125%) and Fragment Mono, both
   OFL-1.1, self-hosted from @fontsource 5.3.0; licences beside the files. */
@font-face {
  font-family: "Archivo"; font-style: normal; font-display: swap;
  font-weight: 100 900; font-stretch: 62% 125%;
  src: url(/assets/fonts/archivo-latin-ext-standard-normal.woff2) format("woff2-variations");
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: "Archivo"; font-style: normal; font-display: swap;
  font-weight: 100 900; font-stretch: 62% 125%;
  src: url(/assets/fonts/archivo-latin-standard-normal.woff2) format("woff2-variations");
  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: "Fragment Mono"; font-style: normal; font-display: swap; font-weight: 400;
  src: url(/assets/fonts/fragment-mono-latin-ext-400-normal.woff2) format("woff2");
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: "Fragment Mono"; font-style: normal; font-display: swap; font-weight: 400;
  src: url(/assets/fonts/fragment-mono-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;
}

:root {
  color-scheme: light dark;
  --cloud: #eef0f2; --cloud-2: #e2e6e9; --cloud-3: #d3d8dc;
  --ink: #1b1f22; --ink-2: #3c4247; --ink-3: #5c636a; --ink-4: #a7aeb4;
  --forest: #006400; --forest-wash: #dcebdc;
  --blood: #660000; --blood-wash: #f2dede;
  --skin-1: #f3d6c2; --skin-2: #dcae8e; --skin-3: #c68a64; --skin-4: #a0643f; --skin-5: #7e4a2c;
  --brush: var(--skin-1); --rest: var(--skin-2); --hold: var(--skin-3);
  --press: var(--skin-4); --on-press: #ffffff; --grip: var(--skin-5);
  --rule: 1px solid var(--ink); --rule-soft: 1px solid var(--ink-4);
  --face: "Archivo", system-ui, sans-serif;
  --wire: "Fragment Mono", ui-monospace, monospace;
  --display: var(--face); --display-w: 300; --display-s: 62%;
  --door: var(--face); --door-w: 600; --door-s: 125%;
  --lede-w: 300; --lede-s: 87%;
  --rail: 88px;
  --edge: clamp(1.25rem, 5vw, 4.5rem);
  --ease: cubic-bezier(.16, 1, .3, 1);
}
@media (prefers-color-scheme: dark) {
  :root {
    --cloud: #16191c; --cloud-2: #1f2327; --cloud-3: #2e3439;
    --ink: #e6e9ec; --ink-2: #b8bec3; --ink-3: #868f96; --ink-4: #4a5157;
    --forest: #7fc07f; --forest-wash: #15291a;
    --blood: #e06666; --blood-wash: #3a1a1a;
    --brush: rgb(126 74 44 / .4); --rest: var(--skin-5); --hold: var(--skin-4);
    --press: var(--skin-3); --on-press: #16191c; --grip: var(--skin-2);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 1.5rem; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0; background: var(--cloud); color: var(--ink);
  font: 400 1rem/1.6 var(--face); font-stretch: 100%;
  -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
}
::selection { background: var(--rest); color: var(--ink); }
:where(a, button, summary, [tabindex]):focus-visible { outline: 2px solid var(--grip); outline-offset: 2px; }
a { color: var(--blood); text-decoration-thickness: 1px; text-underline-offset: .2em; }
a:hover { background: var(--brush); box-shadow: 0 0 0 .2em var(--brush); color: var(--ink); text-decoration-color: var(--hold); }
code, pre, kbd { font-family: var(--wire); font-size: .875em; font-variant-ligatures: none; }
html { scrollbar-color: var(--ink-4) transparent; scrollbar-width: thin; }

.skip { position: absolute; left: .75rem; top: .75rem; z-index: 10; padding: .5rem .75rem; background: var(--ink); color: var(--cloud); font: .8125rem var(--wire); clip-path: inset(50%); }
.skip:focus { clip-path: none; }

/* ---------- the frame: a depth rail and a page ---------- */
.frame { display: grid; grid-template-columns: var(--rail) minmax(0, 1fr); min-height: 100vh; }
.rail {
  position: sticky; top: 0; height: 100vh; border-right: var(--rule);
  display: grid; grid-template-rows: 4.5rem repeat(3, 1fr); font: .75rem/1.2 var(--wire);
}
.rail a {
  position: relative; display: flex; align-items: flex-end; padding: 1rem 0; justify-content: center;
  border-top: var(--rule); color: var(--ink-2); text-decoration: none; overflow: hidden;
}
.rail a:hover { box-shadow: none; }
.rail .home { border-top: 0; align-items: center; font-size: .8125rem; color: var(--ink); }
.rail a[data-door="1"] { background: var(--cloud); }
.rail a[data-door="2"] { background: var(--cloud-2); }
.rail a[data-door="3"] { background: var(--cloud-3); }
.rail a span { writing-mode: vertical-rl; transform: rotate(180deg); position: relative; z-index: 1; transition: color .5s var(--ease); white-space: nowrap; }
.rail a span b { font: var(--door-w) .8125rem var(--door); font-stretch: var(--door-s); letter-spacing: .04em; margin-inline-start: .6rem; }
.rail a::before {
  content: ""; position: absolute; inset: 0; background: var(--press);
  clip-path: inset(100% 0 0 0); transition: clip-path .6s var(--ease);
}
.rail a:hover::before { clip-path: inset(92% 0 0 0); background: var(--hold); }
.rail a[aria-current="true"]::before { clip-path: inset(0 0 0 0); background: var(--press); }
.rail a[aria-current="true"] span { color: var(--on-press); }
@media (prefers-reduced-motion: reduce) { .rail a::before, .rail a span { transition: none; } }

.page { min-width: 0; padding: 0 var(--edge) 0; }
.bar {
  height: 4.5rem; display: flex; align-items: center; gap: 1.5rem; border-bottom: var(--rule-soft);
  font: .8125rem var(--wire);
}
.bar .host { color: var(--ink); margin-right: auto; }
.bar a { color: var(--ink-2); text-decoration: none; }
.bar a:hover { color: var(--ink); }

/* ---------- opening ---------- */
.opening {
  display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); gap: clamp(2rem, 5vw, 4.5rem);
  padding: clamp(2.5rem, 6vh, 4rem) 0 clamp(2.5rem, 5vh, 3.5rem); border-bottom: var(--rule); align-items: end;
}
h1 {
  margin: 0; font-family: var(--display); font-weight: var(--display-w); font-stretch: var(--display-s); text-transform: lowercase;
  font-size: clamp(3.5rem, 8.4vw, 6rem); line-height: .9; letter-spacing: -.01em; text-wrap: balance;
}
.rule { margin: 0; font-size: clamp(1.25rem, 2vw, 1.5rem); font-weight: var(--lede-w); font-stretch: var(--lede-s); line-height: 1.3; text-wrap: pretty; }
.rule em { font-style: normal; color: var(--forest); }
.rule + p { margin: 1rem 0 0; color: var(--ink-2); max-width: 58ch; text-wrap: pretty; }

/* the ground rules: a definition list, not a card grid */
.ground { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); border-bottom: var(--rule-soft); margin: 0; }
.ground div { padding: 1.25rem 1.5rem 1.25rem 0; }
.ground div + div { padding-left: 1.5rem; border-left: var(--rule-soft); }
.ground dt { font: var(--door-w) .75rem var(--door); font-stretch: var(--door-s); letter-spacing: .05em; text-transform: lowercase; color: var(--ink-2); }
.ground dd { margin: .35rem 0 0; font-size: .9375rem; line-height: 1.5; }

/* ---------- a door ---------- */
.door { padding: clamp(3rem, 8vh, 5rem) 0 clamp(2.5rem, 6vh, 4rem); border-bottom: var(--rule); }
.door-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: .5rem 1.25rem; }
h2 { margin: 0; font-size: clamp(1.75rem, 3.4vw, 2.5rem); font-family: var(--display); font-weight: var(--display-w); font-stretch: var(--display-s); line-height: 1; text-transform: lowercase; }
h2 b { font-family: var(--door); font-weight: var(--door-w); font-stretch: var(--door-s); font-size: .45em; letter-spacing: .06em; vertical-align: .35em; margin-right: .75rem; color: var(--ink-2); }
.door-head .terms { font: .8125rem var(--wire); color: var(--ink-3); }
/* what a call through this door carries: one ruled strip under each door's title */
.cred { display: grid; grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr) minmax(0, 1fr); margin: 1.25rem 0 0; border-top: var(--rule); border-bottom: var(--rule-soft); }
.cred div { padding: .85rem 1.25rem .9rem 0; min-width: 0; }
.cred div + div { padding-left: 1.25rem; border-left: var(--rule-soft); }
.cred dt { font: var(--door-w) .75rem var(--door); font-stretch: var(--door-s); letter-spacing: .05em; text-transform: lowercase; color: var(--ink-3); }
.cred dd { margin: .3rem 0 0; font-size: .9375rem; line-height: 1.45; color: var(--ink-2); overflow-wrap: anywhere; }
.cred dd strong { font-weight: 600; color: var(--ink); }
.door > p, .door .lead { margin: 1rem 0 0; max-width: 66ch; color: var(--ink-2); text-wrap: pretty; }
h3 { margin: 2.75rem 0 .75rem; font: var(--door-w) .8125rem var(--door); font-stretch: var(--door-s); letter-spacing: .06em; text-transform: lowercase; color: var(--ink-2); }

/* calls: one ruled line each; open one to read its wire */
.calls { margin-top: 1.75rem; border-top: var(--rule); }
.call { border-bottom: var(--rule-soft); }
.call summary {
  list-style: none; cursor: pointer; display: grid; grid-template-columns: 4.25rem minmax(0, 19rem) minmax(0, 1fr) 1.25rem;
  gap: 1rem; align-items: baseline; padding: .95rem 0;
}
.call summary::-webkit-details-marker { display: none; }
.call summary:hover { background: var(--brush); box-shadow: -.5rem 0 0 var(--brush), .5rem 0 0 var(--brush); }
.verb { font: .75rem var(--wire); color: var(--ink-3); }
.path { font: .875rem var(--wire); overflow-wrap: anywhere; }
.what { font-size: .9375rem; color: var(--ink-2); }
.tick { width: 12px; height: 12px; align-self: center; justify-self: end; color: var(--ink-3); transition: transform .4s var(--ease); }
.call[open] .tick { transform: rotate(45deg); }
.call[open] summary { background: none; box-shadow: none; }
.call[open] .path { color: var(--ink); }
.wire {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.25fr); gap: 1px; background: var(--ink-4);
  border: var(--rule-soft); margin: 0 0 1.5rem;
}
.wire > div { background: var(--cloud-2); padding: 1rem 1.15rem; min-width: 0; }
.wire .label { display: flex; justify-content: space-between; gap: 1rem; font: .75rem var(--wire); color: var(--ink-3); margin-bottom: .6rem; }
.wire pre { margin: 0; font-size: .8125rem; line-height: 1.7; color: var(--ink-2); white-space: pre; overflow-x: auto; scrollbar-width: thin; }
.wire .note { grid-column: 1 / -1; font-size: .875rem; color: var(--ink-2); padding-block: .75rem; }
.k { color: var(--ink); }
.lin { color: var(--forest); }
.err { color: var(--blood); }
.st { font: .75rem var(--wire); color: var(--ink-3); }
@media (prefers-reduced-motion: no-preference) {
  .call[open] .wire { animation: unfold .45s var(--ease); }
  @keyframes unfold { from { clip-path: inset(0 0 100% 0); } to { clip-path: inset(0 0 0 0); } }
}

/* the pass, as three steps that really are a sequence */
.steps { list-style: none; padding: 0; margin: 1.75rem 0 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border-top: var(--rule); counter-reset: s; }
.steps li { padding: 1rem 1.5rem 1.25rem 0; counter-increment: s; }
.steps li + li { padding-left: 1.5rem; border-left: var(--rule-soft); }
.steps li::before { content: "step " counter(s); display: block; font: .75rem var(--wire); color: var(--ink-3); margin-bottom: .4rem; }
.steps code { display: block; margin-bottom: .35rem; color: var(--ink); }
.steps p { margin: 0; font-size: .9375rem; color: var(--ink-2); }

/* elements: the agents, named, not routed */
.elements { width: 100%; border-collapse: collapse; margin-top: 1.75rem; border-top: var(--rule); }
.elements th, .elements td { text-align: left; vertical-align: baseline; padding: .9rem 1.25rem .9rem 0; border-bottom: var(--rule-soft); }
.elements th { font: var(--display-w) 1.75rem/1 var(--display); font-stretch: var(--display-s); width: 9rem; }
.elements td:nth-child(2) { font: .8125rem var(--wire); color: var(--ink-2); width: 8rem; }
.elements td:last-child { color: var(--ink-2); font-size: .9375rem; }
.elements tr.later th, .elements tr.later td { color: var(--ink-3); }
.keyline { margin-top: 2rem; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(1.5rem, 4vw, 3rem); }
.keyline > div { border-top: var(--rule-soft); padding-top: 1rem; }
.keyline p { margin: 0; color: var(--ink-2); font-size: .9375rem; max-width: 52ch; }
.keyline p + p { margin-top: .6rem; }
.never { color: var(--ink); }

/* errors */
.codes { width: 100%; border-collapse: collapse; margin-top: 1.5rem; font-variant-numeric: tabular-nums; }
.codes th, .codes td { text-align: left; padding: .7rem 1.25rem .7rem 0; border-bottom: var(--rule-soft); vertical-align: baseline; }
.codes thead th { font: var(--door-w) .75rem var(--door); font-stretch: var(--door-s); letter-spacing: .05em; color: var(--ink-2); border-bottom: var(--rule); }
.codes td:first-child { font: .8125rem var(--wire); color: var(--ink-3); width: 4rem; }
.codes td:nth-child(2) { font: .8125rem var(--wire); color: var(--blood); width: 14rem; }
.codes td:last-child { color: var(--ink-2); font-size: .9375rem; }

.close { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 2rem; padding: 3rem 0 4rem; align-items: end; }
.close p { margin: 0; font-size: clamp(1.25rem, 2vw, 1.5rem); font-weight: var(--lede-w); font-stretch: var(--lede-s); max-width: 40ch; }
.close nav { display: flex; gap: 1.5rem; font: .8125rem var(--wire); flex-wrap: wrap; }
.synthetic { font: .75rem var(--wire); color: var(--ink-3); }

/* ---------- one breakpoint ---------- */
@media (max-width: 800px) {
  .frame { grid-template-columns: 1fr; }
  .rail {
    position: sticky; top: 0; z-index: 5; height: auto; border-right: 0; border-bottom: var(--rule);
    grid-template-rows: none; grid-template-columns: auto repeat(3, 1fr);
  }
  .rail a { border-top: 0; border-left: var(--rule); padding: .8rem .5rem; min-height: 44px; align-items: center; }
  .rail .home { border-left: 0; padding-inline: .9rem; }
  .rail a span { writing-mode: horizontal-tb; transform: none; }
  .rail a span b { display: none; }
  .rail a::before { clip-path: inset(0 100% 0 0); }
  .rail a:hover::before { clip-path: inset(0 100% 0 0); }
  .rail a[aria-current="true"]::before { clip-path: inset(0); }
  html { scroll-padding-top: 4rem; }
  .bar { height: auto; padding: 1rem 0; flex-wrap: wrap; gap: .5rem 1.25rem; }
  .bar .host { width: 100%; }
  .opening { grid-template-columns: 1fr; }
  .ground { grid-template-columns: 1fr 1fr; }
  .ground div, .ground div + div { padding: 1rem 1rem 1rem 0; border-left: 0; }
  .ground div:nth-child(even) { padding-left: 1rem; border-left: var(--rule-soft); }
  .ground div:nth-child(n+3) { border-top: var(--rule-soft); }
  .call summary { grid-template-columns: 3.25rem minmax(0, 1fr) 1.25rem; }
  .call .what { grid-column: 2; grid-row: 2; font-size: .875rem; }
  .call .tick { grid-column: 3; grid-row: 1; }
  .wire { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .cred { grid-template-columns: 1fr; }
  .cred div, .cred div + div { padding: .75rem 0; border-left: 0; }
  .cred div + div { border-top: var(--rule-soft); }
  .steps li, .steps li + li { padding: 1rem 0; border-left: 0; border-bottom: var(--rule-soft); }
  .elements th { width: 6rem; font-size: 1.5rem; }
  .elements td:nth-child(2) { display: none; }
  .keyline { grid-template-columns: 1fr; }
  .codes td:nth-child(2) { width: auto; }
  .codes td:first-child { width: 3rem; }
  .close { grid-template-columns: 1fr; }
}
.elements caption { caption-side: bottom; text-align: left; padding-top: .75rem; }