/* ============================================================
   A WORLD IN 640K — shared stylesheet
   Machine-room brutalism, 1994: dark bitplane-blue console,
   amber phosphor signal color, DOS text-mode chrome. Categorical
   chart palette validated (7 slots) against --surface #121826.
   Follows the almanac house conventions (cf. costa-concordia).
   ============================================================ */

:root {
  --bg:        #0b0e14;   /* powered-down monitor */
  --surface:   #121826;   /* panels / figure surface (palette validated vs this) */
  --surface-2: #182136;   /* raised panel */
  --surface-3: #223048;   /* control chrome */
  --ink:       #e6e2d6;   /* warm paper white */
  --ink-2:     #b8bcc4;   /* secondary */
  --muted:     #7d8794;   /* captions, axes */
  --line:      rgba(230, 226, 214, 0.12);
  --line-2:    rgba(230, 226, 214, 0.05);

  --amber:     #f0a132;   /* phosphor signal accent — headings, brand, highlights */
  --amber-hi:  #ffc35c;
  --amber-dim: #9a6a1e;
  --cyan:      #5ad7e6;   /* links, live values */
  --dosblue:   #16244f;   /* EDIT.COM blue for code chips */

  --good:      #4cc26e;
  --warn:      #e0a63c;
  --danger:    #e05252;

  /* categorical chart series — validated 7-slot fixed order on --surface */
  --s1: #4f8fe0; --s2: #bd8b16; --s3: #22916b; --s4: #7d86ef;
  --s5: #d466a8; --s6: #d47c2e; --s7: #3399ba;

  --serif: Georgia, "Iowan Old Style", "Times New Roman", serif;
  --dos:   "VT323", "Cascadia Mono", "Consolas", monospace;
  --mono:  ui-monospace, "Cascadia Mono", "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  /* faint memory-cell dot grid */
  background-image:
    radial-gradient(rgba(230,226,214,0.022) 1px, transparent 1px);
  background-size: 26px 26px;
  color: var(--ink);
  font: 17px/1.65 var(--serif);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: rgba(240, 161, 50, 0.35); }

a { color: var(--cyan); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- masthead & chapter tabs ---------- */

.masthead {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(11, 14, 20, 0.93);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.masthead-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 10px 20px 0;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 18px;
}
.masthead .brand {
  font-family: var(--dos);
  font-size: 22px;
  letter-spacing: 0.14em;
  color: var(--amber);
  white-space: nowrap;
  text-shadow: 0 0 12px rgba(240, 161, 50, 0.35);
}
.masthead .brand a { color: inherit; text-decoration: none; }
.masthead .strap {
  font-family: var(--dos);
  font-size: 15px;
  letter-spacing: 0.05em;
  color: var(--muted);
}
.tabs {
  max-width: 1100px;
  margin: 0 auto;
  padding: 6px 14px 0;
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
  overflow-x: auto;
}
.tabs a {
  font-family: var(--dos);
  font-size: 16px;
  letter-spacing: 0.04em;
  color: var(--ink-2);
  padding: 5px 10px 7px;
  border: 1px solid transparent;
  border-bottom: none;
  white-space: nowrap;
}
.tabs a:hover { color: var(--amber-hi); text-decoration: none; }
.tabs a[aria-current="page"] {
  color: var(--amber);
  background: var(--surface);
  border-color: var(--line);
  border-radius: 4px 4px 0 0;
}

/* ---------- page & hero ---------- */

.page {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px 90px;
}

.hero { padding: 58px 0 8px; position: relative; }
.hero .kicker {
  font-family: var(--dos);
  font-size: 17px;
  letter-spacing: 0.12em;
  color: var(--cyan);
  margin: 0 0 10px;
}
.hero h1 {
  font-family: var(--dos);
  font-weight: 400;
  font-size: clamp(44px, 7vw, 76px);
  line-height: 0.95;
  letter-spacing: 0.01em;
  margin: 0 0 18px;
  color: var(--ink);
  text-shadow: 0 0 24px rgba(240, 161, 50, 0.18);
}
.hero h1 .amber { color: var(--amber); }
.hero .standfirst {
  font-size: 20px;
  line-height: 1.6;
  color: var(--ink-2);
  max-width: 760px;
  margin: 0;
}
/* scanline veil on hero only — decorative, very quiet */
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    to bottom, transparent 0 3px, rgba(0, 0, 0, 0.14) 3px 4px);
  mask-image: linear-gradient(to bottom, rgba(0,0,0,.8), transparent 85%);
  -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,.8), transparent 85%);
}

/* ---------- stat grid ---------- */

.statgrid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 10px;
  margin: 34px 0 8px;
}
.stat {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 14px 14px 12px;
}
.stat .v {
  font-family: var(--dos);
  font-size: 34px;
  line-height: 1;
  color: var(--amber);
}
.stat .v.bad  { color: var(--danger); }
.stat .v.warn { color: var(--warn); }
.stat .v.good { color: var(--good); }
.stat .l {
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.5;
  letter-spacing: 0.03em;
  color: var(--muted);
  margin-top: 7px;
}

/* ---------- prose ---------- */

.prose { max-width: 760px; }
.prose.wide { max-width: none; }

h2 {
  font-family: var(--dos);
  font-weight: 400;
  font-size: 34px;
  letter-spacing: 0.02em;
  color: var(--amber);
  margin: 54px 0 12px;
}
h2::before { content: "▚ "; color: var(--amber-dim); }
h3 {
  font-family: var(--dos);
  font-weight: 400;
  font-size: 24px;
  color: var(--ink);
  margin: 34px 0 8px;
}
p { margin: 0 0 16px; }
.prose li { margin: 0 0 8px; }
em { color: var(--ink); }
strong { color: var(--amber-hi); font-weight: 600; }
hr { border: none; border-top: 1px solid var(--line); margin: 40px 0; }

/* inline code — EDIT.COM chip */
code, kbd {
  font-family: var(--mono);
  font-size: 0.82em;
  background: var(--dosblue);
  color: #cfe3ff;
  border-radius: 3px;
  padding: 1px 5px 2px;
  white-space: nowrap;
}
pre {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 14px 16px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.55;
  color: var(--ink-2);
}
pre code { background: none; color: inherit; padding: 0; white-space: pre; }

/* hex address / segment:offset marginal token */
.addr {
  font-family: var(--mono);
  font-size: 0.8em;
  color: var(--cyan);
  letter-spacing: 0.02em;
}

/* callout asides */
.aside {
  border-left: 3px solid var(--amber-dim);
  background: var(--surface);
  border-radius: 0 6px 6px 0;
  padding: 14px 18px 6px;
  margin: 22px 0;
  font-size: 15.5px;
  color: var(--ink-2);
}
.aside .tag {
  display: inline-block;
  font-family: var(--dos);
  font-size: 15px;
  letter-spacing: 0.1em;
  color: var(--amber);
  margin-bottom: 6px;
}
.aside.danger { border-left-color: var(--danger); }
.aside.danger .tag { color: var(--danger); }

/* ---------- figures: DOS program windows ---------- */

.fig {
  margin: 30px 0 36px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow: hidden;
}
.fig.wide { margin-left: 0; margin-right: 0; }
@media (min-width: 1120px) {
  .fig.wide { margin-left: -140px; margin-right: -140px; }
}
.fig-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 4px 16px;
  padding: 8px 14px;
  background: var(--surface-2);
  border-bottom: 1px solid var(--line);
}
.fig-head .t {
  font-family: var(--dos);
  font-size: 18px;
  letter-spacing: 0.06em;
  color: var(--amber);
}
.fig-head .t::before { content: "■ "; color: var(--amber-dim); }
.fig-head .hint {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
}
.fig-body { position: relative; }
.fig-body canvas { display: block; width: 100%; }
.fig-note {
  padding: 9px 14px 11px;
  border-top: 1px solid var(--line-2);
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.6;
  color: var(--muted);
}
.fig-note a { color: var(--cyan); }

/* event log line under interactive figs */
.evlog {
  padding: 8px 14px;
  border-top: 1px solid var(--line-2);
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-2);
  min-height: 1.6em;
}
.evlog .t { color: var(--amber); }

/* ---------- figure controls ---------- */

.fig-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  background: var(--surface-2);
}
.btn {
  font-family: var(--dos);
  font-size: 17px;
  letter-spacing: 0.05em;
  color: var(--ink);
  background: var(--surface-3);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 4px 14px 6px;
  cursor: pointer;
}
.btn:hover { border-color: var(--amber-dim); color: var(--amber-hi); }
.btn.primary { color: #14100a; background: var(--amber); border-color: var(--amber); }
.btn.primary:hover { background: var(--amber-hi); }
.btn:disabled { opacity: 0.45; cursor: default; }
.ctl {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
}
.ctl output { color: var(--cyan); font-size: 12px; min-width: 46px; }
input[type="range"] { accent-color: var(--amber); }
.seg {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow: hidden;
}
.seg button {
  font-family: var(--dos);
  font-size: 15px;
  color: var(--ink-2);
  background: var(--surface);
  border: none;
  padding: 4px 12px 6px;
  cursor: pointer;
}
.seg button + button { border-left: 1px solid var(--line); }
.seg button[aria-pressed="true"] { background: var(--amber); color: #14100a; }

/* ---------- data tables ---------- */

table.data {
  border-collapse: collapse;
  width: 100%;
  margin: 20px 0 28px;
  font-size: 14px;
}
table.data caption {
  caption-side: top;
  text-align: left;
  font-family: var(--dos);
  font-size: 18px;
  letter-spacing: 0.05em;
  color: var(--amber);
  padding-bottom: 8px;
}
table.data th {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: left;
  color: var(--muted);
  border-bottom: 1px solid var(--line);
  padding: 6px 12px 6px 0;
}
table.data td {
  border-bottom: 1px solid var(--line-2);
  padding: 6px 12px 6px 0;
  color: var(--ink-2);
  vertical-align: top;
}
table.data td.num, table.data th.num { text-align: right; font-family: var(--mono); font-size: 13px; }
table.data td:first-child { color: var(--ink); }
table.data tr.total td { border-top: 1px solid var(--line); color: var(--amber); font-weight: 600; }

/* ---------- chapter footer nav ---------- */

.chapnav {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  margin-top: 70px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.chapnav a {
  font-family: var(--dos);
  font-size: 18px;
  color: var(--ink-2);
  max-width: 46%;
}
.chapnav a:hover { color: var(--amber-hi); text-decoration: none; }
.chapnav .dir {
  display: block;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 3px;
}
.chapnav a.next { text-align: right; margin-left: auto; }

/* ---------- chapter cards (index) ---------- */

.chapters {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
  margin: 30px 0;
}
.chapcard {
  display: block;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 16px 16px 14px;
  color: var(--ink-2);
  transition: border-color 120ms ease, transform 120ms ease;
}
.chapcard:hover {
  text-decoration: none;
  border-color: var(--amber-dim);
  transform: translateY(-2px);
}
.chapcard .num {
  font-family: var(--dos);
  font-size: 15px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}
.chapcard .name {
  font-family: var(--dos);
  font-size: 24px;
  color: var(--amber);
  margin: 2px 0 8px;
}
.chapcard .blurb { font-size: 14px; line-height: 1.55; }

/* ---------- screenshots ---------- */

.shot {
  margin: 26px 0;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow: hidden;
}
.shot img {
  display: block;
  width: 100%;
  image-rendering: pixelated;
}
.shot figcaption {
  padding: 8px 14px 10px;
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.6;
  color: var(--muted);
}
.shotrow {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 14px;
  margin: 26px 0;
}
.shotrow .shot { margin: 0; }

/* ---------- legend chips (shared by canvas figures) ---------- */

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  padding: 9px 14px;
  border-top: 1px solid var(--line-2);
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-2);
}
.legend .key {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.legend .sw {
  width: 10px; height: 10px;
  border-radius: 2px;
  display: inline-block;
}

/* ---------- site footer ---------- */

.sitefoot {
  max-width: 1100px;
  margin: 0 auto;
  padding: 26px 20px 50px;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.7;
  color: var(--muted);
}
.sitefoot a { color: var(--cyan); }

/* ---------- motion ---------- */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
}

/* staggered load-in for hero + statgrid */
@keyframes rise {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: none; }
}
.hero .kicker, .hero h1, .hero .standfirst { animation: rise 500ms ease-out backwards; }
.hero h1 { animation-delay: 90ms; }
.hero .standfirst { animation-delay: 180ms; }
.statgrid .stat { animation: rise 450ms ease-out backwards; }
.statgrid .stat:nth-child(2) { animation-delay: 60ms; }
.statgrid .stat:nth-child(3) { animation-delay: 120ms; }
.statgrid .stat:nth-child(4) { animation-delay: 180ms; }
.statgrid .stat:nth-child(5) { animation-delay: 240ms; }
.statgrid .stat:nth-child(6) { animation-delay: 300ms; }

/* blinking cursor for hero / boot lines */
.cursor::after {
  content: "▌";
  color: var(--amber);
  animation: blink 1.06s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }

@media (max-width: 640px) {
  body { font-size: 16px; }
  .hero { padding-top: 36px; }
  .fig-head .hint { display: none; }
}


/* Clear the fixed "← Almanac" pill. /almanac-back.js pins it to the viewport's
   top-left, [0,0 109x41], with a z-index no document can beat, so a control
   underneath is not merely obscured -- it is untappable, and the tap navigates
   to the catalog instead (ALM-BUG-KILN-00039). A masthead wordmark lands there
   naturally. Unconditional, because the pill sits in the same place at every
   width. Guarded by tests/responsive.test.mjs. */
.masthead-inner { padding-left: 112px; }