/* =========================================================
   SELF-GROWING PERSONAL CURRICULUM — shared stylesheet
   Design goals: comfortable reading on a phone, large touch
   targets, no external fonts or CDNs, and layout/navigation that
   work without JavaScript (JS only adds progress tracking).
   ========================================================= */

:root {
  /* ---- Brand theme (default: Patitos Fortune). Change these to rebrand.
     See docs/customizing.md. Keep text/accent contrast at WCAG AA (4.5:1). ---- */
  --color-bg:        #faf6ee;
  --color-bg-raised: #ffffff;
  --color-text:      #2b2620;
  --color-text-soft: #55493c;
  --color-border:    #ddd0ba;
  --color-accent:    #aa5f1b;   /* warm accessible accent */
  --color-accent-dark: #8a4a12;
  --color-accent-soft: #f3e3c8;
  --color-tier1:     #3f7a4e;   /* green   - foundations */
  --color-tier2:     #a3661a;   /* amber   - intermediate */
  --color-tier3:     #6b4d99;   /* violet  - deep dive */
  --color-focus:     #1c5fa8;
  --color-done:      #2f6b3e;   /* read / completed */
  --color-done-soft: #e3f0e5;

  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-head: Georgia, "Times New Roman", Times, serif;

  --max-width: 46rem;
  --radius: 10px;
}

/* ---------- Reset-ish basics ---------- */
* { box-sizing: border-box; }

html {
  font-size: 112.5%; /* ~18px base, scales up below for readability */
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 1.15rem;
  line-height: 1.65;
  min-height: 100vh;
}

/* Ordinary prose wraps at word boundaries by default, which is what we
   want for table headers like "Position" (breaking those mid-letter, as
   word-break:break-word would, is worse than the problem it solves). Only
   elements likely to carry one long unbroken token — links and inline
   code such as repository paths or function signatures — get permission
   to break mid-word, and only as a last resort. */
/* General safety net: prose can contain an unbroken slash-joined compound
   (e.g. "Undo/Redo/Replay", "KernelExplainer/Explainer") with no ordinary
   space to wrap at, which would otherwise be clipped by overflow-x:hidden
   on a narrow screen. Table cells are deliberately excluded and reset back
   to normal breaking just below: a wide table already scrolls within its
   own .table-scroll box, and breaking a short header word like "Position"
   mid-letter to avoid that scroll would look far worse than the problem
   it solves. */
p, li, span, a, code, dt, dd, figcaption {
  overflow-wrap: break-word;
  word-break: break-word;
}
.diagram-table th, .diagram-table td,
table.data-table th, table.data-table td {
  overflow-wrap: normal;
  word-break: normal;
}

img { max-width: 100%; display: block; }

h1, h2, h3, h4 {
  font-family: var(--font-head);
  color: var(--color-text);
  line-height: 1.25;
  margin-top: 1.6em;
  margin-bottom: 0.5em;
  /* A lesson title can contain a slash-joined compound ("Undo/Redo/Replay")
     that a narrow screen has no ordinary space to wrap at. */
  overflow-wrap: break-word;
  word-break: break-word;
}

h1 { font-size: 2rem; margin-top: 0; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.2rem; }

p, ul, ol { margin: 0 0 1.1em 0; }
ul, ol { padding-left: 1.4em; }

a {
  color: var(--color-accent-dark);
  text-decoration: underline;
  text-underline-offset: 0.15em;
}
a:hover { color: var(--color-accent); }

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
  border-radius: 4px;
}

code, pre {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.95em;
}

code {
  background: var(--color-accent-soft);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

pre {
  background: #2b2620;
  color: #f3ead9;
  padding: 1em 1.1em;
  border-radius: var(--radius);
  overflow-x: auto;
  line-height: 1.5;
}
pre code { background: none; padding: 0; color: inherit; }

hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 2em 0;
}

/* ---------- Layout shell ---------- */
.page {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.25rem 1.25rem 3rem;
}

.site-header {
  border-bottom: 3px solid var(--color-accent-soft);
  background: var(--color-bg-raised);
}

.site-header .page {
  padding-top: 1.4rem;
  padding-bottom: 1.4rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--color-text);
}

.brand:hover { color: var(--color-accent-dark); }

.brand-logo { width: 2.4rem; height: 2.4rem; flex-shrink: 0; }
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-byline {
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-accent-dark);
  letter-spacing: 0.02em;
}
.brand-byline:empty, .hero-byline:has(.brand-byline:empty) { display: none; }

.brand-name {
  font-family: var(--font-head);
  font-size: 1.4rem;
  font-weight: bold;
}

.crumb {
  font-size: 1rem;
  color: var(--color-text-soft);
}

.site-footer {
  border-top: 3px solid var(--color-accent-soft);
  background: var(--color-bg-raised);
  margin-top: 3rem;
  color: var(--color-text-soft);
  font-size: 0.95rem;
}

.brand-footer {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.4rem;
  font-weight: 600;
  color: var(--color-text);
}
.brand-footer .brand-name { font-size: 1rem; }
.brand-footer-logo { width: 1.5rem; height: 1.5rem; }

/* ---------- Home hero ---------- */
.home-hero {
  text-align: center;
  padding: 1.5rem 0 1rem;
}

.hero-logo { width: 5.5rem; height: 5.5rem; margin: 0 auto 0.5rem; }
.home-hero h1 { margin-bottom: 0.3rem; }
.home-hero h1 .brand-name { font-size: inherit; }
.hero-byline { margin: 0 0 1rem; }
.hero-byline .brand-byline {
  display: inline-block;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  border: 1px solid var(--color-accent);
  border-radius: 999px;
  padding: 0.15em 0.8em;
  background: var(--color-bg-raised);
}

.home-hero h1 { font-size: 2.4rem; }

.home-subtitle {
  font-size: 1.25rem;
  color: var(--color-text-soft);
  max-width: 34rem;
  margin: 0 auto 1rem;
}

/* ---------- Course card (home page) ---------- */
.course-card {
  display: block;
  background: var(--color-bg-raised);
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin: 1.5rem 0;
  text-decoration: none;
  color: var(--color-text);
  min-height: 44px;
}

.course-card:hover,
.course-card:focus-visible {
  border-color: var(--color-accent);
}

.course-card h2 {
  margin-top: 0;
  font-size: 1.6rem;
}

.course-meta {
  color: var(--color-text-soft);
  font-size: 1.05rem;
  margin-bottom: 0.75rem;
}

.course-path {
  font-size: 1.05rem;
  color: var(--color-text-soft);
}

.course-card .btn { margin-top: 1rem; }

/* ---------- Section heading for tiers ---------- */
.tier-heading {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  margin-top: 2.2rem;
  padding-top: 0.4rem;
}

.tier-heading h2 { margin: 0; }

.tier-badge {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  padding: 0.25em 0.65em;
  border-radius: 999px;
  color: #fff;
  white-space: nowrap;
}

.tier-badge.tier-1 { background: var(--color-tier1); }
.tier-badge.tier-2 { background: var(--color-tier2); }
.tier-badge.tier-3 { background: var(--color-tier3); }

.tier-intro {
  color: var(--color-text-soft);
  margin-top: -0.4rem;
}

/* ---------- Lesson list card (course index) ---------- */
.lesson-list {
  list-style: none;
  margin: 0 0 1rem 0;
  padding: 0;
}

.lesson-card {
  display: block;
  background: var(--color-bg-raised);
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  margin-bottom: 1rem;
  text-decoration: none;
  color: var(--color-text);
}

.lesson-card:hover,
.lesson-card:focus-visible {
  border-color: var(--color-accent);
}

.lesson-card-top {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.lesson-number {
  font-family: var(--font-head);
  font-weight: bold;
  font-size: 1.5rem;
  color: var(--color-accent-dark);
  min-width: 2.2ch;
}

.lesson-title {
  font-size: 1.2rem;
  font-weight: 600;
  flex: 1 1 12rem;
}

.lesson-duration {
  font-size: 0.95rem;
  color: var(--color-text-soft);
  white-space: nowrap;
}

.lesson-desc {
  margin: 0.5rem 0 0;
  color: var(--color-text-soft);
}

/* ---------- Lesson page header ---------- */
.lesson-header {
  border-bottom: 2px solid var(--color-accent-soft);
  padding-bottom: 1rem;
  margin-bottom: 1.5rem;
}

.lesson-header .lesson-number {
  font-size: 2.2rem;
}

.lesson-header h1 {
  margin-top: 0.2rem;
  margin-bottom: 0.4rem;
}

.lesson-tagline {
  font-size: 1.15rem;
  color: var(--color-text-soft);
  font-style: italic;
  margin-bottom: 0;
}

.lesson-meta-row {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  align-items: center;
  margin-top: 0.7rem;
}

.duration-badge,
.source-badge {
  display: inline-block;
  font-size: 0.95rem;
  color: var(--color-text-soft);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 0.2em 0.75em;
  max-width: 100%;
  /* A source badge may carry a long unbroken token such as a
     slash-joined repository name; let it wrap on narrow screens. */
  overflow-wrap: break-word;
  word-break: break-word;
}

/* ---------- Lesson body sections ---------- */
.lesson-section {
  margin: 2rem 0;
}

.lesson-section > h2 {
  border-left: 5px solid var(--color-accent);
  padding-left: 0.6rem;
}

.callout {
  background: var(--color-accent-soft);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  margin: 1.2rem 0;
}

.callout h3 { margin-top: 0; }

/* ---------- Simple diagram / state-table helpers ---------- */
/* .table-scroll wraps each table so a wide one (many columns) scrolls
   horizontally within its own small box on a narrow screen, instead of
   either forcing the whole page to scroll sideways or being clipped by
   html/body's page-level overflow-x:hidden below. The <table> itself keeps
   its normal display:table so header and body columns stay aligned. */
.table-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  max-width: 100%;
  margin: 1.2rem 0;
}
.diagram-table,
table.data-table {
  border-collapse: collapse;
  margin: 0;
  font-size: 1rem;
}

.diagram-table caption,
table.data-table caption {
  text-align: left;
  color: var(--color-text-soft);
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}

.diagram-table th, .diagram-table td,
table.data-table th, table.data-table td {
  border: 1px solid var(--color-border);
  padding: 0.55rem 0.7rem;
  text-align: left;
  vertical-align: top;
}

.diagram-table th, table.data-table th {
  background: var(--color-accent-soft);
}

.state-flow {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  margin: 1.2rem 0;
}

.state-chip {
  display: inline-block;
  border: 2px solid var(--color-border);
  border-radius: 999px;
  padding: 0.4em 0.9em;
  background: var(--color-bg-raised);
  font-weight: 600;
}

.state-chip.is-current { border-color: var(--color-accent); color: var(--color-accent-dark); }

.state-arrow { font-size: 1.3rem; color: var(--color-text-soft); }

/* ---------- Exercise / reveal ---------- */
.exercise {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  margin: 1.2rem 0;
  background: var(--color-bg-raised);
}

.exercise h3 { margin-top: 0; }

details {
  margin-top: 0.9rem;
  border-top: 1px solid var(--color-border);
  padding-top: 0.8rem;
}

summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--color-accent-dark);
  padding: 0.4rem 0.2rem;
  min-height: 44px;
  display: list-item;
}

details[open] summary { margin-bottom: 0.6rem; }

/* ---------- Takeaways ---------- */
.takeaways {
  background: var(--color-bg-raised);
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
}

.takeaways h2 { margin-top: 0; }
.takeaways ul { margin-bottom: 0; }
.takeaways li { margin-bottom: 0.5em; }

/* ---------- Navigation buttons ---------- */
.btn {
  display: inline-block;
  min-height: 56px;
  min-width: 44px;
  padding: 0.9rem 1.3rem;
  border-radius: var(--radius);
  border: 2px solid var(--color-accent);
  background: var(--color-accent);
  color: #fff !important;
  text-decoration: none !important;
  font-weight: 700;
  font-size: 1.05rem;
  text-align: center;
  line-height: 1.3;
}

.btn:hover, .btn:focus-visible { background: var(--color-accent-dark); border-color: var(--color-accent-dark); }

.btn-secondary {
  background: var(--color-bg-raised);
  color: var(--color-accent-dark) !important;
}

.btn-secondary:hover, .btn-secondary:focus-visible {
  background: var(--color-accent-soft);
}

.btn-disabled {
  background: var(--color-bg-raised);
  border-color: var(--color-border);
  color: var(--color-text-soft) !important;
  cursor: default;
}

.lesson-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin: 2rem 0 1rem;
}

.lesson-nav .btn { width: 100%; }

.lesson-nav-index {
  grid-column: 1 / -1;
}

.home-link-row {
  text-align: center;
  margin-top: 0.5rem;
}

/* ---------- Responsive ---------- */
@media (min-width: 700px) {
  html { font-size: 118.75%; } /* ~19px */
  .home-hero h1 { font-size: 2.8rem; }
}

@media (max-width: 480px) {
  .lesson-nav { grid-template-columns: 1fr; }
  .lesson-header .lesson-number { font-size: 1.8rem; }
  .home-hero h1 { font-size: 2rem; }
}

/* ---------- Reading progress (assets/js/progress.js) ---------- */
.progress-row { margin: 2rem 0 1rem; }
.progress-row .btn { width: 100%; }
.btn[aria-pressed="true"] {
  background: var(--color-done-soft);
  border-color: var(--color-done);
  color: var(--color-done) !important;
}
.lesson-card.is-complete { border-color: var(--color-done); }
.lesson-card.is-complete .lesson-number::after,
.course-card.is-complete h2::after {
  content: " \2713";
  color: var(--color-done);
}
.progress-count:empty { display: none; }
.progress-note {
  font-size: 0.95rem;
  color: var(--color-text-soft);
}
.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 1rem 0;
}
.button-row .btn, .button-row label.btn { flex: 1 1 12rem; cursor: pointer; }
label.btn:focus-within { outline: 3px solid var(--color-focus); outline-offset: 2px; }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap;
}
.status-message { min-height: 1.6em; font-weight: 600; }
.header-link { margin-left: auto; font-size: 0.95rem; }
.example-flag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  border: 1px dashed var(--color-text-soft);
  color: var(--color-text-soft);
  border-radius: 999px;
  padding: 0.1em 0.6em;
  vertical-align: middle;
}

/* No horizontal scroll anywhere */
html, body { max-width: 100%; overflow-x: hidden; }