@font-face { font-family: "Big Shoulders Stencil Display"; src: url("/fonts/big-shoulders-stencil-display.woff2") format("woff2"); font-weight: 100 900; font-display: swap; }
@font-face { font-family: "IBM Plex Sans"; src: url("/fonts/ibm-plex-sans.woff2") format("woff2"); font-weight: 100 700; font-style: normal; font-display: swap; }
@font-face { font-family: "IBM Plex Sans"; src: url("/fonts/ibm-plex-sans-400-italic.woff2") format("woff2"); font-weight: 400; font-style: italic; font-display: swap; }
@font-face { font-family: "IBM Plex Mono"; src: url("/fonts/ibm-plex-mono-400.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "IBM Plex Mono"; src: url("/fonts/ibm-plex-mono-500.woff2") format("woff2"); font-weight: 500; font-display: swap; }

/* Layout: a drawing set. A fixed drawing border and title block frame the
   viewport; each section is one sheet whose spec panel sticks on the left
   while the 3D technical drawing on the right advances with the scroll. */
:root {
  --ground: #123763;       /* cyanotype paper */
  --ground-deep: #0a2346;
  --chalk: #e9f1fb;        /* line work and text */
  --chalk-dim: rgba(233, 241, 251, 0.64);
  --hair: rgba(233, 241, 251, 0.2);
  --amber: #ffb547;        /* sanitizer warnings, the one accent */
  --redline: #ff8a73;      /* revision redlines, used once */
  --stencil: "Big Shoulders Stencil Display", "Arial Narrow", Impact, sans-serif;
  --sans: "IBM Plex Sans", "Helvetica Neue", Arial, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --frame: 12px;
  --gutter: max(40px, env(safe-area-inset-left, 0px));
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  min-height: 100%;
  background-color: var(--ground);
  background-image:
    radial-gradient(120% 90% at 70% 40%, rgba(255, 255, 255, 0.06), rgba(0, 0, 0, 0) 60%),
    linear-gradient(rgba(233, 241, 251, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(233, 241, 251, 0.07) 1px, transparent 1px),
    linear-gradient(rgba(233, 241, 251, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(233, 241, 251, 0.035) 1px, transparent 1px);
  background-size: 100% 100%, 120px 120px, 120px 120px, 24px 24px, 24px 24px;
  background-attachment: fixed;
  color: var(--chalk);
  font: 400 1.0625rem/1.6 var(--sans);
  overflow-x: hidden;
}
body::after { /* cyanotype paper tooth */
  content: ""; position: fixed; inset: 0; pointer-events: none; z-index: 0; opacity: 0.07; mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
a { color: var(--chalk); text-decoration-color: var(--amber); text-underline-offset: 3px; text-decoration-thickness: 1px; }
a:hover { color: var(--amber); }
:focus-visible { outline: 2px solid var(--amber); outline-offset: 3px; }
.mono { font-family: var(--mono); }
.skip { position: absolute; left: -999px; top: 16px; z-index: 50; background: var(--amber); color: var(--ground-deep); padding: 8px 14px; font: 500 0.85rem var(--mono); }
.skip:focus { left: 24px; }

/* ------------------------------------------------------------ the drawing */
#drawing { position: fixed; inset: 0; width: 100vw; height: 100vh; z-index: 1; display: block; }
#annotations { position: fixed; inset: 0; z-index: 2; pointer-events: none; overflow: hidden; }
.anno { position: absolute; left: 0; top: 0; white-space: nowrap; font: 500 11px/1.2 var(--mono); letter-spacing: 0.06em; color: var(--chalk); opacity: 0; will-change: transform, opacity; }
.anno.warn { color: var(--amber); }
.anno.ghost { color: var(--chalk-dim); }

/* drawing border with zone references */
.frame { position: fixed; inset: var(--frame); z-index: 3; pointer-events: none; border: 1.5px solid var(--chalk-dim); }
.frame::after { content: ""; position: absolute; inset: 14px; border: 1px solid var(--hair); }
.zones { position: absolute; display: flex; font: 500 9px var(--mono); color: var(--chalk-dim); letter-spacing: 0.1em; }
.zones-top { left: 14px; right: 14px; top: 0; height: 14px; align-items: center; justify-content: space-around; }
.zones-side { top: 14px; bottom: 14px; left: 0; width: 14px; flex-direction: column; align-items: center; justify-content: space-around; }

/* title block, the page's persistent navigation state */
.titleblock {
  position: fixed; z-index: 4; right: calc(var(--frame) + 14px); bottom: calc(var(--frame) + 14px);
  width: min(360px, calc(100vw - 2 * var(--frame) - 28px));
  background: var(--ground-deep); border: 1.5px solid var(--chalk-dim);
  font-size: 10.5px; letter-spacing: 0.06em; color: var(--chalk);
}
.tb-row { display: flex; gap: 10px; padding: 6px 10px; border-top: 1px solid var(--hair); align-items: baseline; }
.tb-row:first-child { border-top: 0; }
.tb-org { font-weight: 500; letter-spacing: 0.14em; }
.tb-k { color: var(--chalk-dim); font-size: 9px; }
.tb-v { transition: opacity 0.25s ease; }
.tb-split { justify-content: space-between; }
.tb-split > span + span { border-left: 1px solid var(--hair); padding-left: 10px; }

/* ------------------------------------------------------------ sheets */
main { position: relative; z-index: 5; }
.sheet { position: relative; padding-left: var(--gutter); padding-right: max(40px, env(safe-area-inset-right, 0px)); }
#general { min-height: 175vh; }
#spec { min-height: 240vh; }
#roster { min-height: 210vh; }
#catalog { min-height: 210vh; }
#overflow { min-height: 0; }
.panel {
  position: sticky; top: max(13vh, 76px);
  width: min(36rem, 46vw); padding: 26px 28px 28px;
  background: rgba(10, 35, 70, 0.72); border: 1px solid var(--hair);
  backdrop-filter: blur(3px); -webkit-backdrop-filter: blur(3px);
  display: flex; flex-direction: column; gap: 14px;
}
.panel > * { margin: 0; min-width: 0; }
.panel.hero { background: transparent; border: 0; backdrop-filter: none; -webkit-backdrop-filter: none; padding-left: 0; top: max(16vh, 90px); width: min(38rem, 44vw); }
.sheet + .sheet { padding-top: 34vh; }
.stick-wrap { min-height: 150vh; }
.panel.handler { position: relative; top: auto; margin-top: 20vh; margin-bottom: 30vh; }

.eyebrow { font-size: 0.72rem; letter-spacing: 0.18em; color: var(--chalk-dim); }
.stencil { font-family: var(--stencil); font-weight: 800; text-transform: uppercase; letter-spacing: 0.01em; line-height: 0.86; text-wrap: balance; }
h1.stencil { font-size: clamp(3.2rem, 7.4vw, 7.6rem); display: flex; flex-wrap: wrap; gap: 0 0.22em; }
h1 .rec { color: transparent; -webkit-text-stroke: 1.6px var(--chalk); }
h2.stencil { font-size: clamp(2.6rem, 5vw, 4.2rem); }
.lede { font-size: 1.2rem; max-width: 34ch; }
.code { margin: 0; padding: 14px 16px; border-left: 2px solid var(--amber); background: rgba(10, 35, 70, 0.6); font-size: 0.92rem; line-height: 1.6; white-space: pre-wrap; max-width: 30rem; }
.code .kw { color: #9cc4ff; } .code .num { color: var(--amber); } .code .cm { color: var(--chalk-dim); }
.code output { color: var(--amber); font-weight: 500; }
.scrollhint { font-size: 0.7rem; letter-spacing: 0.2em; color: var(--chalk-dim); margin-top: 18px !important; }

/* the clause, set like a standards document */
.clause { display: grid; gap: 10px; }
.clause-no { font-weight: 500; font-size: 1rem; }
.clause-term { margin: 0; font: 500 1.7rem/1.15 var(--sans); }
.clause-term dfn { font-style: normal; }
.clause-def { font-size: 1.15rem; margin: 0; }
.note { margin: 0; font-size: 0.95rem; color: var(--chalk-dim); }
.note .mono { color: var(--chalk); font-size: 0.78rem; letter-spacing: 0.08em; margin-right: 8px; }

/* parts list and revision table */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; border: 1.5px solid var(--chalk-dim); font-size: 0.92rem; font-variant-numeric: tabular-nums; }
th { font: 500 0.68rem var(--mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--chalk-dim); text-align: left; padding: 8px 10px; border-bottom: 1.5px solid var(--chalk-dim); }
td { padding: 10px; border-top: 1px solid var(--hair); vertical-align: top; }
td + td, th + th { border-left: 1px solid var(--hair); }
td.mono { font-size: 0.8rem; white-space: nowrap; }
tr.uninit td { color: rgba(233, 241, 251, 0.42); }
.pill { display: inline-block; padding: 1px 6px; border: 1px solid var(--amber); color: var(--amber); font-size: 0.7rem; letter-spacing: 0.1em; }
.fine { font-size: 0.72rem; color: var(--chalk-dim); letter-spacing: 0.04em; }
.links { display: flex; flex-wrap: wrap; gap: 10px; }

.btn { display: inline-flex; align-items: center; gap: 8px; padding: 10px 14px; border: 1.5px solid var(--chalk); color: var(--chalk); text-decoration: none; font: 500 0.78rem var(--mono); letter-spacing: 0.1em; text-transform: uppercase; background: transparent; transition: background 0.15s ease, color 0.15s ease; }
.btn:hover { background: var(--chalk); color: var(--ground-deep); }
.btn.ghost { border-style: dashed; border-color: var(--chalk-dim); }

/* the sanitizer */
.ubsan { margin: 0; padding: 14px 16px; background: rgba(5, 18, 38, 0.82); border: 1px solid rgba(255, 138, 115, 0.5); color: var(--chalk); font-size: 0.82rem; line-height: 1.55; white-space: pre-wrap; overflow-wrap: anywhere; }
.ubsan .file { color: var(--chalk-dim); } .ubsan .err { color: var(--redline); font-weight: 500; }
.contact { font-size: clamp(1rem, 2.4vw, 1.35rem); overflow-wrap: anywhere; user-select: all; }
.footnote { font-size: 0.82rem; color: var(--chalk-dim); border-top: 1px solid var(--hair); padding-top: 10px; }
.footnote .mono { color: var(--chalk); margin-right: 6px; }
sup a { text-decoration: none; color: var(--amber); font-family: var(--mono); font-size: 0.75em; }

footer { position: relative; z-index: 5; display: flex; flex-wrap: wrap; gap: 6px 26px; padding: 32px var(--gutter) calc(150px + env(safe-area-inset-bottom, 0px)); font-size: 0.7rem; letter-spacing: 0.08em; color: var(--chalk-dim); }

/* ------------------------------------------------------------ narrow screens */
@media (max-width: 820px) {
  :root { --frame: 6px; --gutter: max(24px, env(safe-area-inset-left, 0px)); }
  .zones { display: none; }
  .frame::after { inset: 8px; }
  .sheet { padding-right: max(24px, env(safe-area-inset-right, 0px)); }
  .panel, .panel.hero { width: 100%; }
  .panel { top: auto; position: relative; margin-top: 62vh; }
  .panel.hero { position: relative; margin-top: 0; padding-top: 34vh; gap: 10px; }
  h1.stencil { font-size: clamp(2.6rem, 13vw, 3.6rem); }
  .scrollhint { display: none; }
  .contact { font-size: 3.5vw; }
  #general { min-height: 120vh; }
  #spec, #roster, #catalog { min-height: 0; padding-bottom: 50vh; }
  #overflow { min-height: 0; padding-bottom: 20vh; }
  .panel.handler { margin-top: 40vh; margin-bottom: 10vh; }
  .sheet + .sheet { padding-top: 0; }
  .stick-wrap { min-height: 0; }
  .titleblock { right: calc(var(--frame) + 10px); left: calc(var(--frame) + 10px); bottom: calc(var(--frame) + 10px + env(safe-area-inset-bottom, 0px)); width: auto; font-size: 9.5px; }
  .tb-org { display: none; }
  footer { padding-bottom: calc(120px + env(safe-area-inset-bottom, 0px)); }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .tb-v, .btn { transition: none; }
}
html.no-webgl #drawing { display: none; }
html.ub .titleblock { border-color: var(--redline); }
.hero .lede { max-width: none; text-wrap: pretty; }