/* Shared stylesheet for every lesson and reference sheet in this course.
   Colours and type: green accent, cool greys, Roboto, square corners. */
:root {
  --paper: #ffffff;
  --ink: #404547;
  --muted: #666a6c;
  --rule: #cdd3d6;
  --panel: #f4f8fa;
  --head: #ebeef0;
  --brand: #00893d;
  --brand-dark: #005f14;
  --accent: #00893d;
  --accent-hover: #00702b;
  --warn: #c9a400;
  --sig: #404547;
  --sig-soft: #dde3e6;
  --tick: #a9b1b6;
  --msb: #ce0000;
  --lsb: #00893d;
  --good: #00893d;
  --good-soft: #e0f1e7;
  --bad: #ce0000;
  --bad-soft: #fbe5e5;
  --mono: "Roboto Mono", "JetBrains Mono", "DejaVu Sans Mono", Menlo, Consolas, monospace;
  --sans: Roboto, Arial, Helvetica, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #1c1f20;
    --ink: #e8ecee;
    --muted: #a9b1b6;
    --rule: #4a5053;
    --panel: #26292b;
    --head: #2f3335;
    --accent: #4cc383;
    --accent-hover: #7bd6a4;
    --warn: #dad55e;
    --sig: #cdd3d6;
    --sig-soft: #3d4447;
    --tick: #777d7f;
    --msb: #ff7b7b;
    --lsb: #4cc383;
    --good: #4cc383;
    --good-soft: #173524;
    --bad: #ff7b7b;
    --bad-soft: #452020;
  }
}
/* learn-hub: the same rules when the visitor chose dark */
@media screen {
  :root[data-theme="dark"] {
    --paper: #1c1f20;
    --ink: #e8ecee;
    --muted: #a9b1b6;
    --rule: #4a5053;
    --panel: #26292b;
    --head: #2f3335;
    --accent: #4cc383;
    --accent-hover: #7bd6a4;
    --warn: #dad55e;
    --sig: #cdd3d6;
    --sig-soft: #3d4447;
    --tick: #777d7f;
    --msb: #ff7b7b;
    --lsb: #4cc383;
    --good: #4cc383;
    --good-soft: #173524;
    --bad: #ff7b7b;
    --bad-soft: #452020;
  }
}

* { box-sizing: border-box; }
html { font-size: 17px; }
body {
  margin: 0;
  border-top: 4px solid var(--brand);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  letter-spacing: 0.02em;
  line-height: 1.5;
}
main {
  max-width: 44rem;
  margin: 0 auto;
  padding: 2.5rem 1rem 5rem;
}

.kicker {
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0;
}
h1, h2, h3 { letter-spacing: 0.04em; }
h1 {
  font-weight: 400;
  font-size: 2.1rem;
  line-height: 1.2;
  margin: 0.3rem 0 0.6rem;
  text-wrap: balance;
}
h2 {
  font-weight: 400;
  font-size: 1.45rem;
  line-height: 1.2;
  margin: 2.6rem 0 0.5rem;
}
h3 {
  font-weight: 500;
  font-size: 1.05rem;
  line-height: 1.3;
  margin: 1.6rem 0 0.3rem;
}
p { margin: 0 0 0.9rem; }
.lede { font-size: 1.1rem; color: var(--muted); }
a { color: var(--accent); text-decoration: none; transition: color 0.3s ease-in-out; }
a:hover { color: var(--accent-hover); text-decoration: underline; text-underline-offset: 2px; }
code, kbd, .mono { font-family: var(--mono); font-size: 0.85em; letter-spacing: 0; }
code { background: var(--head); padding: 0.05em 0.3em; }
hr { border: 0; border-top: 1px solid var(--rule); margin: 2.5rem 0; }
small, .small { font-size: 0.8rem; color: var(--muted); }

/* Citation to a spec requirement */
.cite {
  font-family: var(--sans);
  font-size: 0.68rem;
  color: var(--muted);
  white-space: nowrap;
}
.cite a { color: inherit; }

blockquote {
  margin: 1rem 0;
  padding: 0.1rem 0 0.1rem 1rem;
  border-left: 3px solid var(--brand);
  color: var(--muted);
}
blockquote footer { font-style: normal; margin-top: 0.3rem; }

.note, .win, .ask {
  background: var(--panel);
  border-left: 3px solid var(--rule);
  padding: 0.7rem 1rem;
  margin: 1.2rem 0;
  font-size: 0.92rem;
}
.note > :last-child, .win > :last-child, .ask > :last-child { margin-bottom: 0; }
.win { border-left-color: var(--good); }
.ask { border-left-color: var(--brand); }

/* Panels that hold interactive widgets */
.panel {
  border: 1px solid var(--rule);
  background: var(--panel);
  padding: 1rem;
  margin: 1.2rem 0;
}
.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem 1.2rem;
  align-items: end;
  margin-bottom: 0.9rem;
}
.controls label {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  font-family: var(--sans);
  font-size: 0.68rem;
  color: var(--muted);
}
input[type="number"], input[type="text"], select, button {
  font: inherit;
  font-family: var(--sans);
  font-size: 0.8rem;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--rule);
  padding: 0.3rem 0.5rem;
}
input[type="number"] { width: 5.2rem; }
button { cursor: pointer; padding: 0.35rem 0.9rem; transition: background-color 0.3s ease-in-out, border-color 0.3s ease-in-out; }
button:hover { border-color: var(--accent); }
button.primary { background: var(--brand); color: #fff; border-color: var(--brand); }
button.primary:hover { background: var(--brand-dark); border-color: var(--brand-dark); }
button:focus-visible, input:focus-visible, select:focus-visible, .pdu td:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}
.readout {
  font-family: var(--mono);
  font-size: 0.8rem;
  margin: 0.7rem 0 0;
  overflow-wrap: anywhere;
}
.feedback { font-family: var(--sans); font-size: 0.8rem; margin: 0.7rem 0 0; min-height: 1.3em; }
.feedback.good { color: var(--good); }
.feedback.bad { color: var(--bad); }

/* Tables */
.table-wrap { overflow-x: auto; }
table.data { border-collapse: collapse; width: 100%; font-size: 0.88rem; margin: 1rem 0; border: 1px solid var(--rule); }
table.data th, table.data td {
  text-align: left;
  vertical-align: top;
  padding: 0.4rem 0.6rem;
  border-bottom: 1px solid var(--rule);
}
table.data th {
  font-family: var(--sans);
  font-weight: 700;
  font-size: 0.8rem;
  color: var(--ink);
  background: var(--head);
}

/* PDU bit grid (assets/pdu-grid.js) */
.pdu-wrap { overflow-x: auto; }
table.pdu { border-collapse: collapse; font-family: var(--mono); font-size: 0.68rem; margin: 0 auto; }
table.pdu th { font-weight: 400; color: var(--muted); padding: 0.15rem 0.45rem; white-space: nowrap; }
table.pdu td {
  width: 2.6rem;
  height: 2.6rem;
  min-width: 2.6rem;
  border: 1px solid var(--rule);
  background: var(--paper);
  text-align: center;
  vertical-align: middle;
  padding: 0;
  line-height: 1.15;
  position: relative;
}
table.pdu td .pos { display: block; color: var(--muted); font-size: 0.6rem; }
table.pdu td .val { display: block; font-size: 0.85rem; min-height: 1em; }
table.pdu td .sbit { display: block; font-size: 0.55rem; min-height: 1em; }
table.pdu td.sig { background: var(--sig-soft); border-color: var(--sig); }
table.pdu td.sig .sbit { color: var(--sig); }
table.pdu td.msb { box-shadow: inset 0 0 0 2px var(--msb); }
table.pdu td.lsb { box-shadow: inset 0 0 0 2px var(--lsb); }
table.pdu td.msb.lsb { box-shadow: inset 0 0 0 2px var(--msb), inset 0 0 0 4px var(--lsb); }
table.pdu.clickable td { cursor: pointer; }
table.pdu td.picked { background: var(--sig-soft); border-color: var(--sig); }
table.pdu td.right { background: var(--good-soft); border-color: var(--good); }
table.pdu td.wrong { background: var(--bad-soft); border-color: var(--bad); }
table.pdu td.missed { box-shadow: inset 0 0 0 2px var(--bad); }
table.pdu td.hex { border: 0; background: none; width: auto; padding-left: 0.7rem; font-size: 0.8rem; }
.legend { font-family: var(--sans); font-size: 0.68rem; color: var(--muted); margin: 0.6rem 0 0; }
.legend .sw {
  display: inline-block; width: 0.8rem; height: 0.8rem; vertical-align: -0.12rem;
  margin: 0 0.25rem 0 0.7rem; border: 1px solid var(--rule); background: var(--paper);
}
.legend .sw:first-child { margin-left: 0; }
.legend .sw.sig { background: var(--sig-soft); border-color: var(--sig); }
.legend .sw.msb { box-shadow: inset 0 0 0 2px var(--msb); }
.legend .sw.lsb { box-shadow: inset 0 0 0 2px var(--lsb); }

/* Quiz (assets/quiz.js) */
.quiz .q { margin: 1.4rem 0; }
.quiz .q p.prompt { margin-bottom: 0.5rem; }
.quiz .opts { display: grid; gap: 0.4rem; }
.quiz .opts button {
  text-align: left;
  font-family: var(--sans);
  font-size: 0.8rem;
  padding: 0.5rem 0.7rem;
}
.quiz .opts button.right { background: var(--good-soft); border-color: var(--good); }
.quiz .opts button.wrong { background: var(--bad-soft); border-color: var(--bad); }
.quiz .opts button:disabled { cursor: default; color: var(--ink); opacity: 1; }
.quiz .why { font-size: 0.88rem; margin: 0.5rem 0 0; }
.quiz .score { font-family: var(--sans); font-size: 0.8rem; }

nav.course {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  font-family: var(--sans);
  font-size: 0.72rem;
  border-top: 1px solid var(--rule);
  padding-top: 0.8rem;
  margin-top: 3rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

@media (max-width: 34rem) {
  html { font-size: 16px; }
  table.pdu td { width: 2.1rem; height: 2.3rem; min-width: 2.1rem; }
}

@media print {
  html { font-size: 11pt; }
  body { background: #fff; color: #000; border-top: 0; }
  main { max-width: none; padding: 0; }
  .no-print, nav.course { display: none; }
  .panel, .note, .win, .ask { break-inside: avoid; }
  h2, h3 { break-after: avoid; }
  a { color: inherit; text-decoration: none; }
  table.pdu td.sig { -webkit-print-color-adjust: exact; print-color-adjust: exact; }
}

/* Flow diagram: boxes joined by arrows */
.flow { display: flex; align-items: stretch; gap: 0.3rem; flex-wrap: wrap; margin: 1.2rem 0; font-family: var(--sans); font-size: 0.72rem; }
.flow .box { flex: 1 1 7rem; border: 1px solid var(--rule); background: var(--panel); padding: 0.6rem 0.7rem; }
.flow .box strong { display: block; font-size: 0.85rem; margin-bottom: 0.2rem; }
.flow .box.main { border-color: var(--sig); background: var(--sig-soft); }
.flow .arrow { align-self: center; color: var(--muted); font-size: 1rem; }

/* Word cards: one plain-language definition each */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); gap: 0.7rem; margin: 1rem 0; }
.card { border: 1px solid var(--rule); padding: 0.7rem 0.9rem; background: var(--panel); }
.card h3 { margin: 0 0 0.2rem; font-family: var(--sans); font-size: 0.85rem; font-weight: 600; }
.card p { margin: 0; font-size: 0.92rem; }
.card .tag { font-family: var(--sans); font-size: 0.62rem; letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); }

/* Running timeline (assets/timeline.js) */
.timeline svg { width: 100%; height: auto; display: block; }
.timeline .lane-label { font-family: var(--sans); font-size: 11px; fill: var(--ink); }
.timeline .lane-line { stroke: var(--rule); stroke-width: 1; }
.timeline .cursor { stroke: var(--accent); stroke-width: 1.5; }
.timeline .mark { fill: var(--sig); }
.timeline .mark.bus { fill: var(--good); }
.timeline .mark.tick { fill: var(--tick); }
.timeline .mark.wait { fill: var(--paper); stroke: var(--sig); stroke-width: 2; }
.timeline .mark-text { font-family: var(--sans); font-size: 10px; fill: var(--muted); text-anchor: middle; }
.timeline .buttons { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 0.8rem 0 0; }

/* Stepper (assets/stepper.js) */
.step-text { min-height: 3.2em; margin: 0.8rem 0; }
.stack { display: grid; gap: 0.25rem; margin: 0 0 0.8rem; font-family: var(--sans); font-size: 0.75rem; }
.stack .layer { border: 1px solid var(--rule); background: var(--paper); padding: 0.45rem 0.7rem; }
.stack .layer.active { border-color: var(--sig); background: var(--sig-soft); }
.stack .layer small { font-family: var(--sans); }

/* A packet drawn as a row of signal cells */
.pkt { display: flex; flex-wrap: wrap; gap: 0.3rem; margin: 0.4rem 0; font-family: var(--mono); font-size: 0.75rem; }
.pkt .cell { border: 1px solid var(--rule); background: var(--paper); padding: 0.3rem 0.6rem; min-width: 5rem; }
.pkt .cell b { display: block; font-size: 1rem; font-weight: 600; }
.pkt .cell.new { border-color: var(--good); background: var(--good-soft); }
.pkt .cell.bad { border-color: var(--bad); background: var(--bad-soft); }
.pkt .cell.dim { color: var(--muted); }
.pkt-label { font-family: var(--sans); font-size: 0.68rem; color: var(--muted); margin: 0.8rem 0 0; }

/* Small running log and result lists */
.log { list-style: none; padding: 0; margin: 0.6rem 0 0; font-family: var(--mono); font-size: 0.75rem; }
.log li { padding: 0.2rem 0; border-top: 1px solid var(--rule); }
.ok { color: var(--good); }
.no { color: var(--bad); }
.bigval { font-family: var(--mono); font-size: 1.3rem; }
ol.pipeline { list-style: none; padding: 0; margin: 0.6rem 0 0; display: grid; gap: 0.25rem; font-size: 0.88rem; }
ol.pipeline li { border: 1px solid var(--rule); background: var(--paper); padding: 0.4rem 0.7rem; }
ol.pipeline li.done { border-color: var(--good); background: var(--good-soft); }
ol.pipeline li.stop { border-color: var(--bad); background: var(--bad-soft); }
ol.pipeline li.skip { color: var(--muted); }

/* Contents list on the course home page */
ol.toc { padding-left: 1.6rem; margin: 0.3rem 0 0; }
ol.toc li { padding: 0.15rem 0; }

/* Plain word -> AUTOSAR word table at the end of a lesson */
.words { font-size: 0.85rem; }

/* Configuration tree */
ul.tree, ul.tree ul { list-style: none; margin: 0; padding-left: 1.1rem; border-left: 1px solid var(--rule); }
ul.tree { padding-left: 0; border-left: 0; font-family: var(--mono); font-size: 0.78rem; margin: 1rem 0; }
ul.tree li { padding: 0.15rem 0 0.15rem 0.6rem; }
ul.tree li span { font-family: var(--sans); color: var(--muted); font-size: 0.85rem; }
.chips { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 0.9rem; }
.chips button[aria-pressed="true"] { background: var(--brand); color: #fff; border-color: var(--brand); }
.bits { font-family: var(--mono); font-size: 0.95rem; letter-spacing: 0.08em; overflow-wrap: anywhere; }
.bits .copy { color: var(--msb); }
.bits .sign { color: var(--msb); font-weight: 700; text-decoration: underline; }

/* Configuration help (config/*.html, assets/com-config.js) */
fieldset.ask-set { border: 0; border-top: 1px solid var(--rule); margin: 1.1rem 0 0; padding: 0.7rem 0 0; min-width: 0; }
fieldset.ask-set:first-of-type { border-top: 0; margin-top: 0; padding-top: 0; }
fieldset.ask-set legend { font-family: var(--sans); font-size: 0.68rem; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); padding: 0 0.5rem 0 0; }
fieldset.ask-set legend a { text-transform: none; letter-spacing: 0; }
.ask-row { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 0.3rem 1rem; padding: 0.3rem 0; font-size: 0.92rem; }
.ask-row > span:first-child { flex: 1 1 14rem; }
.ask-row .field { display: flex; align-items: center; gap: 0.4rem; font-family: var(--sans); font-size: 0.72rem; color: var(--muted); }
.ask-row input[type="text"] { width: 9rem; }
.ask-row select { max-width: 19rem; }
.ask-row input[type="checkbox"] { width: 1.05rem; height: 1.05rem; accent-color: var(--accent); }
.ask-row small { display: block; }
ul.issues { list-style: none; padding: 0; margin: 0.8rem 0; display: grid; gap: 0.3rem; font-size: 0.9rem; }
ul.issues li { border-left: 3px solid var(--rule); background: var(--panel); padding: 0.4rem 0.7rem; }
ul.issues li.error { border-left-color: var(--bad); background: var(--bad-soft); }
ul.issues li.warn { border-left-color: var(--warn); }
ul.issues li.fine { border-left-color: var(--good); background: var(--good-soft); }
ul.issues .rule { font-family: var(--sans); font-size: 0.62rem; color: var(--muted); white-space: nowrap; }
pre.code { font-family: var(--mono); font-size: 0.66rem; line-height: 1.45; background: var(--panel); border: 1px solid var(--rule); padding: 0.8rem; margin: 0.6rem 0; overflow: auto; max-height: 26rem; }
details.more { margin: 0.8rem 0; }
details.more > summary { cursor: pointer; font-family: var(--sans); font-size: 0.75rem; color: var(--accent); }
table.data.settings td:first-child { font-size: 0.66rem; color: var(--muted); min-width: 6.5rem; }
table.data.settings tr.first td { border-top: 1px solid var(--muted); }
table.data.settings td:nth-child(3) { white-space: nowrap; }
table.pdu.small-grid { margin: 0; }
table.pdu.small-grid td { width: 2rem; height: 2rem; min-width: 2rem; }
.legend .sw.ub { background: var(--good-soft); border-color: var(--good); }
.buttons-row { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 0.8rem 0; }
section.recipe, section.symptom { border-top: 1px solid var(--rule); margin-top: 2rem; padding-top: 0.2rem; }
section.recipe h3, section.symptom h3 { font-size: 1.1rem; margin-top: 1rem; }
section.recipe .want { color: var(--muted); }
.search { width: 100%; max-width: 24rem; }
input.search[type="text"] { width: 100%; }
ol.checks { padding-left: 1.3rem; }
ol.checks li { margin-bottom: 0.5rem; }
@media print {
  pre.code { max-height: none; overflow: visible; white-space: pre-wrap; }
  section.recipe, section.symptom { break-inside: avoid; }
}
[hidden] { display: none !important; }
ul#contents { list-style: none; padding-left: 0; font-size: 0.92rem; }
ul#contents li { padding: 0.1rem 0; }