/* ============================================================
   learn.appcafe.in — design system
   Token system: paper + ink + teal accent + amber highlight.
   Signature element: the "trail" — a spine of numbered nodes
   that visualizes progress through a topic (see .trail).
   ============================================================ */

:root {
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 20px;
  --maxw: 880px;
  --font-display: 'Space Grotesk', 'Segoe UI', system-ui, sans-serif;
  --font-body: 'Inter', 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, monospace;
}

/* ---------- theme colors ----------
   Same mechanism as tools.appcafe.in / appcafe.in: a data-theme attribute
   on <html>, toggled by a cookie shared across *.appcafe.in so switching
   theme on one AppCafe app carries over to the others. Dark is the
   default look (matches the rest of the AppCafe suite) — the bare :root
   block below supplies dark values so the page never flashes unstyled,
   and [data-theme="dark"] repeats them explicitly for symmetry with the
   "light" override block beneath it. */
:root,
[data-theme="dark"] {
  --paper: #0F172A;
  --paper-translucent: rgba(15,23,42,0.88);
  --panel: #1E293B;
  --ink: #F1F5F9;
  --ink-soft: #CBD5E1;
  --ink-faint: #94A3B8;
  --accent: #14B8A6;
  --accent-dark: #2DD4BF;
  --accent-soft: rgba(20,184,166,0.14);
  --highlight: #FFC94D;
  --highlight-soft: rgba(255,201,77,0.14);
  --warn: #F87171;
  --warn-soft: rgba(248,113,113,0.14);
  --border: #334155;
  --code-bg: #0B1120;
  --code-text: #BEF2E4;
  --code-keyword: #FFC94D;
  --shadow: 0 2px 10px rgba(0,0,0,0.3);
  --shadow-lift: 0 10px 30px rgba(0,0,0,0.45);
}
[data-theme="light"] {
  --paper: #F7F8FA;
  --paper-translucent: rgba(247,248,250,0.92);
  --panel: #FFFFFF;
  --ink: #132540;
  --ink-soft: #4B5A70;
  --ink-faint: #8492A6;
  --accent: #0EA394;
  --accent-dark: #0B7F73;
  --accent-soft: #E3F6F3;
  --highlight: #FFC94D;
  --highlight-soft: #FFF3D9;
  --warn: #E2574C;
  --warn-soft: #FBE7E5;
  --border: #DCE3EA;
  --code-bg: #1B2130;
  --code-text: #BEF2E4;
  --code-keyword: #FFC94D;
  --shadow: 0 2px 10px rgba(19, 37, 64, 0.06);
  --shadow-lift: 0 10px 30px rgba(19, 37, 64, 0.12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  line-height: 1.65;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  transition: background 0.15s ease, color 0.15s ease;
}
img { max-width: 100%; display: block; }
a { color: var(--accent-dark); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible {
  outline: 3px solid var(--highlight);
  outline-offset: 2px;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--ink);
  line-height: 1.2;
  margin: 0 0 0.5em;
}
h1 { font-size: clamp(1.9rem, 5vw, 2.7rem); font-weight: 700; letter-spacing: -0.01em; }
h2 { font-size: clamp(1.4rem, 3.4vw, 1.8rem); font-weight: 700; margin-top: 2em; }
h3 { font-size: 1.15rem; font-weight: 700; }
p { margin: 0 0 1.1em; color: var(--ink-soft); }
strong { color: var(--ink); }
.mark { background: linear-gradient(transparent 60%, var(--highlight-soft) 60%); padding: 0 2px; color: var(--ink); font-weight: 600; }

code {
  font-family: var(--font-mono);
  background: var(--accent-soft);
  color: var(--accent-dark);
  padding: 0.1em 0.4em;
  border-radius: 5px;
  font-size: 0.88em;
}
pre {
  background: var(--code-bg);
  color: var(--code-text);
  padding: 18px 20px;
  border-radius: var(--radius);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.6;
  margin: 0 0 1.4em;
  box-shadow: var(--shadow);
}
pre code { background: none; color: inherit; padding: 0; }

/* ---------- layout shell ---------- */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.wide { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: var(--paper-translucent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.site-header .bar {
  max-width: 1100px; margin: 0 auto; padding: 14px 20px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
/* Logo: icon dot + two-tone wordmark, same layout pattern as tools.appcafe.in's
   "App"/"Cafe" split — here rendered as "AppCafe" (two-tone) + "Learn" (accent). */
.brand { display: flex; align-items: center; gap: 9px; font-family: var(--font-display); font-weight: 700; font-size: 1.15rem; color: var(--ink); }
.brand .dot { width: 10px; height: 10px; border-radius: 50%; background: var(--accent); display: inline-block; flex-shrink: 0; }
.brand .logo-word { display: flex; align-items: baseline; gap: 5px; }
.brand .logo-app { color: var(--ink); }
.brand .logo-cafe { color: var(--ink-faint); }
.brand .logo-product { color: var(--accent-dark); }
.brand small { font-family: var(--font-body); font-weight: 500; color: var(--ink-faint); font-size: 0.7rem; letter-spacing: 0.04em; text-transform: uppercase; }

nav.primary { display: flex; align-items: center; gap: 22px; }
nav.primary a { color: var(--ink-soft); font-weight: 600; font-size: 0.94rem; }
nav.primary a.active { color: var(--accent-dark); }
nav.primary a:hover { text-decoration: none; color: var(--accent-dark); }

/* ---------- category dropdown nav (desktop) ----------
   Generated by build.js from data/topics.json's category/subCategory/
   patternGroup fields (see ARCHITECTURE.md §2b) — never hand-edit the
   markup this produces inside partials/header.html; edit topics.json and
   re-run node build.js instead. */
.nav-cat { position: relative; }
.nav-cat-btn {
  display: flex; align-items: center; gap: 4px;
  background: none; border: none; cursor: pointer;
  font-family: var(--font-body); font-size: 0.94rem; font-weight: 600;
  color: var(--ink-soft); padding: 6px 4px;
  transition: color 0.15s;
}
.nav-cat-btn:hover, .nav-cat.open .nav-cat-btn { color: var(--accent-dark); }
.nav-chevron { width: 12px; height: 12px; flex-shrink: 0; transition: transform 0.2s; }
.nav-cat.open .nav-chevron { transform: rotate(180deg); }

.nav-cat-menu {
  display: none;
  position: absolute; top: calc(100% + 12px); left: 0;
  background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: var(--shadow-lift);
  min-width: 220px; padding: 6px 0;
  z-index: 200;
}
.nav-cat.open .nav-cat-menu { display: block; }

.nav-cat-item {
  display: block; padding: 9px 16px;
  font-size: 0.9rem; font-weight: 500; color: var(--ink-soft);
  white-space: nowrap; transition: background 0.12s, color 0.12s;
}
.nav-cat-item:hover { background: var(--accent-soft); color: var(--accent-dark); text-decoration: none; }

/* second-level flyout, e.g. Design Principles → SOLID / Design Patterns (All) / Individual Patterns */
.nav-cat-group { position: relative; }
.nav-cat-group-btn {
  display: flex; align-items: center; justify-content: space-between; gap: 10px;
  width: 100%; background: none; border: none; cursor: pointer; text-align: left;
  padding: 9px 16px; font-family: var(--font-body);
  font-size: 0.9rem; font-weight: 600; color: var(--ink-soft);
  transition: background 0.12s, color 0.12s;
}
.nav-cat-group-btn:hover, .nav-cat-group.open > .nav-cat-group-btn { background: var(--accent-soft); color: var(--accent-dark); }
.nav-subchevron { width: 11px; height: 11px; flex-shrink: 0; transition: transform 0.15s; }
.nav-cat-group.open > .nav-cat-group-btn .nav-subchevron { transform: rotate(-90deg); }

.nav-cat-submenu {
  display: none;
  position: absolute; top: -6px; left: 100%; margin-left: 2px;
  background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: var(--shadow-lift);
  min-width: 210px; max-height: 340px; overflow-y: auto;
  padding: 6px 0;
  z-index: 201;
}
.nav-cat-group.open > .nav-cat-submenu { display: block; }
/* third-level grouping inside a submenu, e.g. Individual Patterns → Creational/Structural/Behavioral */
.nav-subgroup-label {
  padding: 8px 16px 4px; font-family: var(--font-display);
  font-size: 0.7rem; font-weight: 700; color: var(--ink-faint);
  text-transform: uppercase; letter-spacing: 0.05em;
}

@media (hover: hover) {
  .nav-cat:hover > .nav-cat-menu { display: block; }
  .nav-cat-group:hover > .nav-cat-submenu { display: block; }
  .nav-cat-group:hover > .nav-cat-group-btn { background: var(--accent-soft); color: var(--accent-dark); }
}

/* Theme toggle button — same show/hide-by-data-theme technique as tools.appcafe.in */
.theme-toggle {
  display: flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; border-radius: 50%;
  background: none; border: 1px solid var(--border); cursor: pointer;
  font-size: 1rem; line-height: 1; flex-shrink: 0;
  transition: background 0.15s, border-color 0.15s;
}
.theme-toggle:hover { background: var(--accent-soft); border-color: var(--accent); }
.theme-toggle .theme-icon-light { display: none; }
[data-theme="light"] .theme-toggle .theme-icon-dark { display: none; }
[data-theme="light"] .theme-toggle .theme-icon-light { display: inline; }

.menu-toggle {
  display: none; background: none; border: 1px solid var(--border); border-radius: var(--radius-sm);
  width: 40px; height: 40px; cursor: pointer; align-items: center; justify-content: center;
}
.menu-toggle span, .menu-toggle span::before, .menu-toggle span::after {
  content: ""; display: block; width: 18px; height: 2px; background: var(--ink); position: relative; transition: 0.2s;
}
.menu-toggle span::before { position: absolute; top: -6px; }
.menu-toggle span::after { position: absolute; top: 6px; }

@media (max-width: 720px) {
  nav.primary {
    position: absolute; top: 100%; left: 0; right: 0; background: var(--panel);
    flex-direction: column; align-items: stretch; gap: 0; border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-lift);
    max-height: 0; overflow: hidden; overflow-y: auto; transition: max-height 0.25s ease;
  }
  /* generous cap so the full nested category list (30+ topics) can scroll within the panel
     instead of being clipped — actual visible height is limited by the viewport, not this number */
  nav.primary.open { max-height: 80vh; }
  nav.primary > a { width: 100%; padding: 14px 20px; border-top: 1px solid var(--border); }
  nav.primary .theme-toggle { margin: 10px 20px; }
  .menu-toggle { display: flex; }

  /* collapse the desktop flyout/hover behavior into a mobile accordion:
     each level toggles open via the .open class (added by JS on tap), not hover */
  .nav-cat-btn { width: 100%; justify-content: space-between; padding: 14px 20px; border-top: 1px solid var(--border); }
  .nav-cat-menu {
    display: none; position: static; box-shadow: none; border: none; border-radius: 0;
    background: var(--paper); width: 100%; min-width: 0; padding: 0;
  }
  .nav-cat.open .nav-cat-menu { display: block; }
  .nav-cat-item { padding: 12px 20px 12px 32px; border-top: 1px solid var(--border); }
  .nav-cat-group-btn { padding: 12px 20px 12px 32px; border-top: 1px solid var(--border); }
  .nav-cat-submenu {
    display: none; position: static; box-shadow: none; border: none; border-radius: 0;
    background: var(--panel); width: 100%; min-width: 0; max-height: none; padding: 0;
  }
  .nav-cat-group.open > .nav-cat-submenu { display: block; }
  .nav-cat-group.open > .nav-cat-group-btn .nav-subchevron { transform: rotate(90deg); }
  .nav-cat-submenu .nav-cat-item { padding-left: 44px; }
  .nav-subgroup-label { padding-left: 44px; }
}

/* ---------- footer ---------- */
.site-footer { border-top: 1px solid var(--border); margin-top: 80px; padding: 40px 0 50px; color: var(--ink-faint); }
.site-footer .wide { display: flex; flex-wrap: wrap; gap: 30px; justify-content: space-between; }
.site-footer h4 { color: var(--ink); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 10px; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: 6px; }
.site-footer a { color: var(--ink-faint); }
.site-footer a:hover { color: var(--accent-dark); }
.footer-bottom { max-width: 1100px; margin: 30px auto 0; padding: 20px 20px 0; border-top: 1px solid var(--border); font-size: 0.85rem; }

/* "Powered by AppCafe.in" bar — same content/link pattern as tools.appcafe.in's
   fixed bottom bar, but kept in-flow (not position:fixed) since lesson pages
   here scroll much longer than a single-screen calculator and a fixed bar
   would need bottom-padding compensation added to every one of this site's
   90+ pages. Placed directly under .site-footer's link columns. */
.powered-bar {
  border-top: 1px solid var(--border);
  padding: 14px 20px;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 12px;
  max-width: 1100px; margin: 0 auto;
}
.powered-pages { display: flex; align-items: center; gap: 18px; }
.powered-pages a { font-size: 0.8rem; color: var(--ink-faint); }
.powered-pages a:hover { color: var(--accent-dark); }
.powered-link { display: inline-flex; align-items: center; gap: 7px; color: inherit; flex-shrink: 0; }
.powered-icon { border-radius: 4px; display: block; }
.powered-label { font-size: 0.68rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-faint); }
.powered-brand { font-size: 0.85rem; font-weight: 700; color: var(--accent-dark); transition: color 0.15s; }
.powered-link:hover .powered-brand { color: var(--accent); }

/* ---------- hero / catalog ---------- */
.hero { padding: 56px 0 20px; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; background: var(--accent-soft); color: var(--accent-dark);
  font-weight: 700; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; padding: 6px 12px; border-radius: 999px; margin-bottom: 18px; }

/* ---------- topic search ---------- */
.search-bar { margin: 22px 0 8px; }
.search-bar input[type="search"] {
  width: 100%; max-width: 420px; font-family: var(--font-body); font-size: 0.98rem;
  padding: 12px 18px; border: 1.5px solid var(--border); border-radius: 999px;
  background: var(--panel); color: var(--ink); box-shadow: var(--shadow);
}
.search-bar input[type="search"]:focus { border-color: var(--accent); outline: none; box-shadow: 0 0 0 4px var(--accent-soft); }
.search-bar input[type="search"]::placeholder { color: var(--ink-faint); }
.search-empty { color: var(--ink-faint); font-size: 0.95rem; margin: 24px 0; }

.topic-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 20px; margin: 30px 0 60px; }
.topic-card { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 26px; box-shadow: var(--shadow); transition: transform 0.15s ease, box-shadow 0.15s ease; position: relative; }
.topic-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lift); }
.topic-card .icon { font-size: 2rem; margin-bottom: 10px; }
.topic-card .category-pill { position: absolute; top: 22px; right: 22px; background: var(--accent-soft); color: var(--accent-dark); font-size: 0.7rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.03em; padding: 3px 10px; border-radius: 999px; }
.topic-card h3 { margin-bottom: 6px; padding-right: 90px; }
.topic-card .level { font-size: 0.8rem; color: var(--ink-faint); font-weight: 600; text-transform: uppercase; letter-spacing: 0.03em; margin-bottom: 10px; }
.topic-card p { margin-bottom: 16px; font-size: 0.95rem; }
.topic-card .progress-mini { height: 6px; border-radius: 4px; background: var(--border); overflow: hidden; margin-bottom: 14px; }
.topic-card .progress-mini > i { display: block; height: 100%; background: var(--accent); }
.btn { display: inline-flex; align-items: center; gap: 8px; background: var(--ink); color: #fff; font-weight: 700; padding: 10px 18px; border-radius: 999px; font-size: 0.92rem; border: none; cursor: pointer; }
.btn:hover { background: var(--accent-dark); text-decoration: none; }
.btn.ghost { background: transparent; color: var(--ink); border: 1.5px solid var(--border); }
.btn.ghost:hover { border-color: var(--accent); color: var(--accent-dark); background: var(--accent-soft); }
.btn.accent { background: var(--accent); }
.btn.accent:hover { background: var(--accent-dark); }

/* ---------- lesson layout ---------- */
.lesson-shell { display: grid; grid-template-columns: 64px 1fr; gap: 36px; max-width: 1020px; margin: 0 auto; padding: 30px 20px 100px; align-items: start; }
@media (max-width: 820px) { .lesson-shell { grid-template-columns: 1fr; padding-top: 14px; } }

.breadcrumb { font-size: 0.85rem; color: var(--ink-faint); margin-bottom: 18px; }
.breadcrumb a { color: var(--ink-faint); font-weight: 600; }
.breadcrumb a:hover { color: var(--accent-dark); }

/* trail: signature progress spine */
.trail { position: sticky; top: 90px; display: flex; flex-direction: column; align-items: center; }
.trail .seg { width: 2px; flex: 1; background: var(--border); min-height: 30px; }
.trail .seg.done { background: var(--accent); }
.trail .node {
  width: 34px; height: 34px; border-radius: 50%; border: 2px solid var(--border); background: var(--panel);
  display: flex; align-items: center; justify-content: center; font-family: var(--font-display); font-weight: 700; font-size: 0.8rem; color: var(--ink-faint);
  flex-shrink: 0;
}
.trail .node.done { background: var(--accent); border-color: var(--accent); color: #fff; }
.trail .node.current { border-color: var(--accent); color: var(--accent-dark); box-shadow: 0 0 0 4px var(--accent-soft); }
@media (max-width: 820px) {
  .trail { display: none; }
  .progress-top { display: block !important; }
}
.progress-top { display: none; margin-bottom: 26px; }
.progress-top .track { height: 8px; background: var(--border); border-radius: 6px; overflow: hidden; }
.progress-top .track > i { display: block; height: 100%; background: var(--accent); }
.progress-top .label { font-size: 0.8rem; color: var(--ink-faint); margin-top: 6px; font-weight: 600; }

/* ---------- callout boxes ---------- */
.box { border-radius: var(--radius); padding: 20px 22px; margin: 26px 0; border: 1.5px solid; }
.box h4 { font-family: var(--font-display); margin: 0 0 8px; font-size: 0.98rem; display: flex; align-items: center; gap: 8px; }
.box p:last-child { margin-bottom: 0; }
.box.bottom-line { background: var(--accent-soft); border-color: #BEE7E1; }
.box.bottom-line h4 { color: var(--accent-dark); }
.box.watch { background: var(--warn-soft); border-color: #F3C5C0; }
.box.watch h4 { color: var(--warn); }
.box.dumb { background: #F3F1FB; border-color: #DCD5F5; }
.box.dumb h4 { color: #6C4FCE; }
.box.tryit { background: var(--panel); border: 1.5px dashed var(--ink-faint); }
.box.tryit h4 { color: var(--ink); }

/* ---------- quiz ---------- */
.quiz { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px 24px; margin: 26px 0; box-shadow: var(--shadow); }
.quiz h4 { font-family: var(--font-display); margin-bottom: 14px; }
.quiz .opt { display: block; width: 100%; text-align: left; background: var(--paper); border: 1.5px solid var(--border); border-radius: var(--radius-sm); padding: 12px 14px; margin-bottom: 8px; cursor: pointer; font-size: 0.95rem; color: var(--ink); font-family: var(--font-body); }
.quiz .opt:hover { border-color: var(--accent); }
.quiz .opt.correct { background: var(--accent-soft); border-color: var(--accent); }
.quiz .opt.wrong { background: var(--warn-soft); border-color: var(--warn); }
.quiz .feedback { margin-top: 10px; font-weight: 600; font-size: 0.92rem; min-height: 1.2em; }
.quiz .feedback.ok { color: var(--accent-dark); }
.quiz .feedback.no { color: var(--warn); }

/* ---------- lesson footer nav ---------- */
.lesson-nav { display: flex; justify-content: space-between; align-items: center; margin-top: 50px; padding-top: 26px; border-top: 1px solid var(--border); gap: 16px; flex-wrap: wrap; }
.lesson-nav .side { display: flex; flex-direction: column; gap: 4px; }
.lesson-nav .side small { color: var(--ink-faint); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.04em; font-weight: 700; }
.complete-btn { display: flex; align-items: center; gap: 8px; }
.complete-btn.done { background: var(--accent-dark); }

.badge-done { display: inline-flex; align-items: center; gap: 6px; background: var(--accent-soft); color: var(--accent-dark); font-weight: 700; font-size: 0.8rem; padding: 5px 12px; border-radius: 999px; }

/* ---------- share button + toast ---------- */
.share-btn { padding: 10px 16px; }
.share-btn svg { width: 16px; height: 16px; }

.share-toast { position: fixed; bottom: 1.5rem; left: 50%; transform: translateX(-50%); background: var(--ink); color: #fff; padding: 0.6rem 1.25rem; border-radius: 999px; font-size: 0.85rem; font-weight: 600; z-index: 9999; opacity: 0; pointer-events: none; transition: opacity 0.2s; }
.share-toast.show { opacity: 1; }

/* ---------- side-by-side comparison (transition guides) ---------- */
.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 2px; margin: 0 0 1.4em; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
.compare .col { background: var(--code-bg); padding: 0; display: flex; flex-direction: column; }
.compare .col-label { font-family: var(--font-display); font-weight: 700; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; padding: 10px 20px; color: var(--code-text); background: rgba(255,255,255,0.06); }
.compare .col pre { margin: 0; border-radius: 0; box-shadow: none; flex: 1; }
@media (max-width: 700px) { .compare { grid-template-columns: 1fr; } }

.box.gotcha { background: var(--warn-soft); border-color: #F3C5C0; }
.box.gotcha h4 { color: var(--warn); }

.box.keydiff { background: #F3F1FB; border-color: #DCD5F5; }
.box.keydiff h4 { color: #6C4FCE; }
.box.keydiff ul { margin: 0; padding-left: 1.2em; }
.box.keydiff li { margin-bottom: 6px; color: var(--ink-soft); }
.box.keydiff li:last-child { margin-bottom: 0; }

/* ---------- design pattern lessons ---------- */
.box.problem { background: var(--warn-soft); border-color: #F3C5C0; }
.box.problem h4 { color: var(--warn); }
.box.solution { background: var(--accent-soft); border-color: #BEE7E1; }
.box.solution h4 { color: var(--accent-dark); }

.example-block { margin: 0 0 1.4em; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); border: 1px solid var(--border); }
.example-block .example-label { font-family: var(--font-display); font-weight: 700; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; padding: 12px 20px; color: var(--ink-faint); background: var(--panel); border-bottom: 1px solid var(--border); }
.example-block pre { margin: 0; border-radius: 0; box-shadow: none; }

.box.usewhen { background: var(--accent-soft); border-color: #BEE7E1; }
.box.usewhen h4 { color: var(--accent-dark); }
.box.usewhen ul, .box.avoidwhen ul { margin: 0; padding-left: 1.2em; }
.box.usewhen li, .box.avoidwhen li { margin-bottom: 6px; color: var(--ink-soft); }
.box.usewhen li:last-child, .box.avoidwhen li:last-child { margin-bottom: 0; }
.box.avoidwhen { background: var(--warn-soft); border-color: #F3C5C0; }
.box.avoidwhen h4 { color: var(--warn); }

.faq { margin: 26px 0; }
.faq-item { border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: 10px; background: var(--panel); box-shadow: var(--shadow); overflow: hidden; }
.faq-item summary { font-family: var(--font-display); font-weight: 700; font-size: 0.95rem; padding: 16px 20px; cursor: pointer; color: var(--ink); list-style: none; display: flex; align-items: center; gap: 10px; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::before { content: "+"; color: var(--accent-dark); font-weight: 700; font-size: 1.1rem; flex-shrink: 0; width: 1em; }
.faq-item[open] summary::before { content: "–"; }
.faq-item .faq-answer { padding: 0 20px 18px 46px; color: var(--ink-soft); }
.faq-item .faq-answer p:last-child { margin-bottom: 0; }

.pattern-pill { display: inline-block; font-size: 0.75rem; font-weight: 700; padding: 3px 10px; border-radius: 999px; text-transform: uppercase; letter-spacing: 0.03em; margin-bottom: 12px; }
.pattern-pill.creational { background: var(--accent-soft); color: var(--accent-dark); }
.pattern-pill.structural { background: var(--highlight-soft); color: #8a6400; }
.pattern-pill.behavioral { background: #F3F1FB; color: #6C4FCE; }

/* ---------- misc ---------- */
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
@media (max-width: 700px) { .two-col { grid-template-columns: 1fr; } }
hr.rule { border: none; border-top: 1px solid var(--border); margin: 40px 0; }
.center { text-align: center; }
.tag { display: inline-block; background: var(--accent-soft); color: var(--accent-dark); font-size: 0.75rem; font-weight: 700; padding: 3px 10px; border-radius: 999px; text-transform: uppercase; letter-spacing: 0.03em; }

/* ---------- cross-links (complementary tools.appcafe.in tools) ----------
   Generated by build.js's buildCrossLinks() from a topic's relatedTools
   array in topics.json, matched against the live tools.appcafe.in catalog
   (see ARCHITECTURE.md §5e). Only rendered on topics that set relatedTools. */
.cross-links { display: flex; flex-direction: column; gap: 12px; margin-top: 16px; }
.cross-link-card {
  display: flex; align-items: flex-start; gap: 14px;
  padding: 16px 18px; border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--accent-soft); text-decoration: none; transition: border-color 0.15s;
}
.cross-link-card:hover { border-color: var(--accent); text-decoration: none; }
.cross-link-icon { font-size: 1.6rem; line-height: 1; flex-shrink: 0; }
.cross-link-title { font-family: var(--font-display); font-weight: 700; color: var(--ink); font-size: 0.95rem; margin: 0 0 4px; }
.cross-link-desc { color: var(--ink-soft); font-size: 0.88rem; margin: 0 0 6px; }
.cross-link-cta { color: var(--accent-dark); font-weight: 700; font-size: 0.85rem; }
