/* ============================================================
   Observability Course — shared stylesheet
   Same design language as the Kafka (red), Go (cyan), gRPC
   (indigo), Postgres (elephant-blue), Airflow (green),
   Containers (amber), Kubernetes (blue), Helm (violet),
   Istio (teal) & CI/CD (orange) courses; themed in magenta.
   Sixth of the deployment/infra course family.
   Tufte-inspired: long measure, quiet palette, real hierarchy.
   Theme-aware (light/dark) + print-friendly.
   ============================================================ */

:root {
  --measure: 43rem;

  --ink:        #1e1219;
  --ink-soft:   #4e3a47;
  --ink-faint:  #7c6472;
  --paper:      #fefbfd;
  --paper-2:    #f9ecf4;
  --rule:       #f0d4e4;

  --accent:     #b02a7d;   /* Observability magenta — eyebrows, emphasis */
  --accent-2:   #971e6b;   /* link magenta */
  --code-bg:    #f9ecf4;
  --code-ink:   #8a1a63;

  --ok:         #1c6b3c;
  --ok-bg:      #e6f4ec;
  --warn:       #8a5a00;
  --warn-bg:    #fbf1dc;
  --key-bg:     #f8e8f2;
  --key-border: #b02a7d;

  --shadow:     0 1px 2px rgba(0,0,0,.05), 0 4px 14px rgba(0,0,0,.05);
  --serif:      "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
  --sans:       -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono:       "SF Mono", "JetBrains Mono", "Fira Code", ui-monospace, Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink:        #f0e4ec;
    --ink-soft:   #ccb4c4;
    --ink-faint:  #9b8090;
    --paper:      #171014;
    --paper-2:    #20161d;
    --rule:       #3a2833;
    --accent:     #ec8fc7;
    --accent-2:   #f0a0d0;
    --code-bg:    #20161d;
    --code-ink:   #efa2d0;
    --ok:         #7fd6a0;
    --ok-bg:      #16281d;
    --warn:       #e6c072;
    --warn-bg:    #2a2312;
    --key-bg:     #2a1122;
    --key-border: #ec8fc7;
    --shadow:     0 1px 2px rgba(0,0,0,.3), 0 4px 14px rgba(0,0,0,.4);
  }
}
:root[data-theme="dark"]  { color-scheme: dark; }
:root[data-theme="light"] { color-scheme: light; }

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  padding: 0 1.4rem 6rem;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.14rem;
  line-height: 1.62;
  letter-spacing: .1px;
}

.wrap { max-width: var(--measure); margin: 0 auto; }
.wide { max-width: 58rem; margin: 0 auto; }

/* ---- Top bar / nav ------------------------------------------------ */
.topbar {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 1.5rem 0 .6rem;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  font-family: var(--sans);
  font-size: .82rem;
  border-bottom: 1px solid var(--rule);
}
.topbar a { color: var(--ink-faint); text-decoration: none; border: 0; }
.topbar a:hover { color: var(--accent-2); }
.topbar .crumbs { letter-spacing: .04em; text-transform: uppercase; }

/* ---- Headings ----------------------------------------------------- */
h1, h2, h3 { font-family: var(--sans); line-height: 1.22; color: var(--ink); }
h1 {
  font-size: 2.1rem;
  font-weight: 800;
  letter-spacing: -.5px;
  margin: 2.2rem 0 .3rem;
}
.eyebrow {
  font-family: var(--sans);
  font-size: .74rem;
  font-weight: 700;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 2rem 0 0;
}
.subtitle {
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.2rem;
  color: var(--ink-soft);
  margin: .1rem 0 1.6rem;
}
h2 {
  font-size: 1.42rem;
  font-weight: 700;
  margin: 2.6rem 0 .5rem;
  padding-top: .4rem;
}
h3 {
  font-size: 1.12rem;
  font-weight: 700;
  margin: 1.8rem 0 .3rem;
  color: var(--ink-soft);
}

p { margin: .7rem 0; }

a {
  color: var(--accent-2);
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, var(--accent-2) 35%, transparent);
}
a:hover { border-bottom-color: var(--accent-2); }

strong { font-weight: 700; }
em { font-style: italic; }

hr {
  border: 0;
  border-top: 1px solid var(--rule);
  margin: 2.4rem 0;
}

ul, ol { padding-left: 1.3rem; }
li { margin: .35rem 0; }

/* ---- Inline + block code ----------------------------------------- */
code {
  font-family: var(--mono);
  font-size: .86em;
  background: var(--code-bg);
  color: var(--code-ink);
  padding: .1em .38em;
  border-radius: 4px;
}
pre {
  font-family: var(--mono);
  font-size: .82rem;
  line-height: 1.5;
  background: var(--code-bg);
  color: var(--ink);
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 1rem 1.1rem;
  overflow-x: auto;
  margin: 1.1rem 0;
}
pre code { background: none; color: inherit; padding: 0; font-size: 1em; }
pre .cmt { color: var(--ink-faint); font-style: italic; }
pre .kw  { color: var(--accent); font-weight: 600; }
pre .str { color: var(--ok); }
pre .typ { color: var(--code-ink); font-weight: 600; }

.filepath {
  display: inline-block;
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--ink-faint);
  background: var(--paper-2);
  border: 1px solid var(--rule);
  border-radius: 5px;
  padding: .06em .5em;
  margin-bottom: .3rem;
}

/* ---- Callouts ----------------------------------------------------- */
.callout {
  border-left: 3px solid var(--rule);
  background: var(--paper-2);
  border-radius: 0 8px 8px 0;
  padding: .85rem 1.1rem;
  margin: 1.3rem 0;
  font-size: 1rem;
}
.callout .label {
  font-family: var(--sans);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  display: block;
  margin-bottom: .25rem;
}
.callout.key  { background: var(--key-bg);  border-left-color: var(--key-border); }
.callout.key  .label { color: var(--key-border); }
.callout.note { background: var(--paper-2); border-left-color: var(--ink-faint); }
.callout.note .label { color: var(--ink-faint); }
.callout.warn { background: var(--warn-bg); border-left-color: var(--warn); }
.callout.warn .label { color: var(--warn); }
.callout.repo { background: var(--ok-bg); border-left-color: var(--ok); }
.callout.repo .label { color: var(--ok); }

/* ---- Cards / grid ------------------------------------------------- */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin: 1.4rem 0;
}
.card {
  background: var(--paper-2);
  border: 1px solid var(--rule);
  border-radius: 10px;
  padding: 1rem 1.1rem;
  box-shadow: var(--shadow);
}
.card h3 { margin-top: 0; font-family: var(--sans); color: var(--ink); }

/* ---- Tables ------------------------------------------------------- */
.table-scroll { overflow-x: auto; margin: 1.2rem 0; }
table {
  border-collapse: collapse;
  width: 100%;
  font-family: var(--sans);
  font-size: .9rem;
}
th, td {
  text-align: left;
  padding: .55rem .7rem;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}
th { font-weight: 700; color: var(--ink); border-bottom: 2px solid var(--ink-faint); }
tbody tr:hover { background: var(--paper-2); }
td code { font-size: .82em; }

/* ---- Pills / tags ------------------------------------------------- */
.pill {
  display: inline-block;
  font-family: var(--sans);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .04em;
  padding: .12em .6em;
  border-radius: 999px;
  background: var(--key-bg);
  color: var(--key-border);
  border: 1px solid color-mix(in srgb, var(--key-border) 40%, transparent);
}
.pill.new  { background: var(--warn-bg); color: var(--warn); border-color: color-mix(in srgb, var(--warn) 40%, transparent); }
.pill.done { background: var(--ok-bg);  color: var(--ok);  border-color: color-mix(in srgb, var(--ok) 40%, transparent); }

/* ---- ASCII / mono diagrams --------------------------------------- */
.diagram {
  font-family: var(--mono);
  font-size: .8rem;
  line-height: 1.35;
  white-space: pre;
  overflow-x: auto;
  background: var(--paper-2);
  border: 1px dashed var(--rule);
  border-radius: 8px;
  padding: 1rem 1.1rem;
  margin: 1.2rem 0;
  color: var(--ink-soft);
}

/* ---- Citations / source strip ------------------------------------ */
.cite { font-size: .82rem; color: var(--ink-faint); }
sup.ref a {
  font-family: var(--sans);
  font-size: .7rem;
  border: 0;
  padding: 0 .1em;
}
.primary-source {
  border: 1px solid var(--key-border);
  border-radius: 10px;
  padding: 1rem 1.1rem;
  margin: 1.6rem 0;
  background: var(--key-bg);
}
.primary-source .label {
  font-family: var(--sans);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--key-border);
}
.primary-source h3 { margin: .2rem 0 .3rem; }

/* ---- Lesson footer nav ------------------------------------------- */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: .9rem;
}
.lesson-nav a { border: 0; }
.ask-teacher {
  font-family: var(--sans);
  font-size: .92rem;
  text-align: center;
  color: var(--ink-soft);
  background: var(--paper-2);
  border: 1px dashed var(--rule);
  border-radius: 10px;
  padding: .9rem 1.1rem;
  margin: 2.6rem 0 0;
}
.ask-teacher strong { color: var(--accent-2); }

/* ---- Quiz widget (styles; behaviour in quiz.js) ------------------- */
.quiz {
  border: 1px solid var(--rule);
  border-radius: 10px;
  padding: 1.1rem 1.2rem;
  margin: 1.6rem 0;
  background: var(--paper-2);
  box-shadow: var(--shadow);
}
.quiz .q {
  font-family: var(--sans);
  font-weight: 700;
  font-size: 1rem;
  margin: 0 0 .8rem;
}
.quiz .q .qn {
  color: var(--accent);
  margin-right: .4rem;
}
.quiz-opt {
  display: block;
  width: 100%;
  text-align: left;
  font-family: var(--sans);
  font-size: .95rem;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: .6rem .8rem;
  margin: .45rem 0;
  cursor: pointer;
  transition: border-color .12s, background .12s;
}
.quiz-opt:hover:not(:disabled) { border-color: var(--accent-2); }
.quiz-opt:disabled { cursor: default; }
.quiz-opt.correct {
  background: var(--ok-bg);
  border-color: var(--ok);
  color: var(--ok);
  font-weight: 600;
}
.quiz-opt.wrong {
  background: var(--warn-bg);
  border-color: var(--warn);
  color: var(--warn);
}
.quiz-explain {
  display: none;
  font-family: var(--serif);
  font-size: .98rem;
  margin-top: .7rem;
  padding-top: .7rem;
  border-top: 1px dashed var(--rule);
  color: var(--ink-soft);
}
.quiz-explain.show { display: block; }
.quiz-explain .verdict { font-weight: 700; font-family: var(--sans); }
.quiz-explain .verdict.right { color: var(--ok); }
.quiz-explain .verdict.nope  { color: var(--warn); }

/* ---- Flashcard (retrieval practice) ------------------------------ */
.flashcard {
  border: 1px solid var(--key-border);
  border-radius: 10px;
  padding: 1rem 1.2rem;
  margin: 1.3rem 0;
  background: var(--key-bg);
  cursor: pointer;
}
.flashcard .fc-front { font-family: var(--sans); font-weight: 700; }
.flashcard .fc-hint {
  font-family: var(--sans); font-size: .78rem; color: var(--ink-faint);
  margin-top: .3rem;
}
.flashcard .fc-back {
  display: none;
  margin-top: .7rem; padding-top: .7rem;
  border-top: 1px dashed var(--key-border);
}
.flashcard.revealed .fc-back { display: block; }
.flashcard.revealed .fc-hint { display: none; }

/* ---- Print -------------------------------------------------------- */
@media print {
  :root { --paper: #fff; --paper-2: #fafafa; --ink: #000; }
  body { font-size: 11pt; padding: 0; }
  .quiz-explain { display: block !important; }
  .flashcard .fc-back { display: block !important; }
  a { color: #000; border: 0; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: .8em; color: #555; }
  .card, .quiz, .callout { break-inside: avoid; }
}

/* ---- Small screens ------------------------------------------------ */
@media (max-width: 640px) {
  body { font-size: 1.06rem; padding: 0 1rem 4rem; }
  h1 { font-size: 1.7rem; }
}