/* ============================================================
   INTRODUCTION TO DIGITAL COMPUTATION
   Main Stylesheet
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Roboto+Slab:wght@300;400;600;700&family=Source+Sans+3:ital,wght@0,300;0,400;0,600;1,400&family=JetBrains+Mono:wght@400;600&display=swap');

/* ── CSS Variables ──────────────────────────────────────────── */
:root {
  --bg:           #F5F2EB;
  --bg-alt:       #EDE9DF;
  --bg-card:      #FDFAF4;
  --ink:          #1A1814;
  --ink-mid:      #4A4640;
  --ink-light:    #8A857C;
  --accent:       #C1440E;        /* burnt orange — warm, technical */
  --accent-light: #F0E6DF;
  --accent-dark:  #8C3009;
  --green:        #2E6B4F;
  --green-light:  #E0EDE7;
  --blue:         #1D4E7A;
  --blue-light:   #DDE8F2;
  --border:       #D8D2C6;
  --border-dark:  #B8B0A4;

  --font-head:    'Roboto Slab', Georgia, serif;
  --font-body:    'Source Sans 3', 'Gill Sans', sans-serif;
  --font-mono:    'JetBrains Mono', 'Courier New', monospace;

  --col-width:    820px;
  --sidebar-w:    260px;
  --radius:       6px;
  --radius-lg:    12px;
}

/* ── Reset & Base ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 18px; scroll-behavior: smooth; }

body {
  background-color: var(--bg);
  background-image:
    radial-gradient(circle at 1px 1px, var(--border) 1px, transparent 0);
  background-size: 28px 28px;
  color: var(--ink);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.75;
  min-height: 100vh;
}

/* ── Layout ─────────────────────────────────────────────────── */
.site-wrapper {
  display: flex;
  min-height: 100vh;
}

/* ── Sidebar ────────────────────────────────────────────────── */
.sidebar {
  width: var(--sidebar-w);
  min-height: 100vh;
  background: var(--ink);
  color: #E8E3DA;
  position: fixed;
  top: 0; left: 0;
  overflow-y: auto;
  z-index: 100;
  display: flex;
  flex-direction: column;
}

.sidebar-logo {
  padding: 28px 24px 20px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.sidebar-logo .book-title {
  font-family: var(--font-head);
  font-size: 0.85rem;
  font-weight: 700;
  color: #fff;
  line-height: 1.3;
  letter-spacing: 0.01em;
  text-decoration: none;
  display: block;
}

.sidebar-logo .book-subtitle {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  color: var(--accent);
  margin-top: 6px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.sidebar-logo .book-author {
  font-size: 0.72rem;
  color: rgba(255,255,255,0.4);
  margin-top: 8px;
}

.nav-unit {
  padding: 20px 0 8px;
}

.nav-unit-label {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.3);
  padding: 0 24px;
  margin-bottom: 4px;
}

.nav-chapter {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 7px 24px;
  text-decoration: none;
  color: rgba(255,255,255,0.6);
  font-size: 0.82rem;
  line-height: 1.3;
  transition: all 0.15s ease;
  border-left: 3px solid transparent;
}

.nav-chapter:hover {
  color: #fff;
  background: rgba(255,255,255,0.05);
  border-left-color: rgba(193,68,14,0.5);
}

.nav-chapter.active {
  color: #fff;
  background: rgba(193,68,14,0.15);
  border-left-color: var(--accent);
}

.nav-chapter .ch-num {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--accent);
  opacity: 0.8;
  min-width: 28px;
  flex-shrink: 0;
}

.nav-chapter.active .ch-num { opacity: 1; }

.sidebar-footer {
  margin-top: auto;
  padding: 20px 24px;
  border-top: 1px solid rgba(255,255,255,0.08);
  font-size: 0.7rem;
  color: rgba(255,255,255,0.25);
  line-height: 1.5;
}

/* ── Main Content Area ──────────────────────────────────────── */
.main-content {
  margin-left: var(--sidebar-w);
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 0 40px 80px;
}

/* ── Chapter Header ─────────────────────────────────────────── */
.chapter-header {
  width: 100%;
  max-width: var(--col-width);
  padding: 64px 0 48px;
  border-bottom: 2px solid var(--ink);
  margin-bottom: 56px;
  position: relative;
  overflow: hidden;
}

.chapter-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
}

.chapter-title {
  font-family: var(--font-head);
  font-size: 2.8rem;
  font-weight: 700;
  line-height: 1.1;
  color: var(--ink);
  letter-spacing: -0.02em;
}

.chapter-deco {
  position: absolute;
  right: -10px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 4.5rem;
  font-weight: 600;
  color: var(--border);
  letter-spacing: -0.05em;
  line-height: 1;
  pointer-events: none;
  user-select: none;
  z-index: 0;
  opacity: 0.6;
}

.chapter-header > *:not(.chapter-deco) {
  position: relative;
  z-index: 1;
}

.chapter-intro {
  margin-top: 24px;
  font-size: 1.1rem;
  color: var(--ink-mid);
  line-height: 1.7;
  max-width: 600px;
}

/* ── Prose ──────────────────────────────────────────────────── */
.prose {
  width: 100%;
  max-width: var(--col-width);
}

.prose h2 {
  font-family: var(--font-head);
  font-size: 1.55rem;
  font-weight: 700;
  color: var(--ink);
  margin: 56px 0 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
  letter-spacing: -0.01em;
  scroll-margin-top: 24px;
}

.prose h3 {
  font-family: var(--font-head);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--ink);
  margin: 36px 0 14px;
  scroll-margin-top: 24px;
}

.prose p {
  margin-bottom: 1.25em;
  color: var(--ink);
}

.prose p:last-child { margin-bottom: 0; }

.prose strong {
  font-weight: 600;
  color: var(--ink);
}

.prose em {
  font-style: italic;
}

.prose ul, .prose ol {
  margin: 1em 0 1.25em 1.5em;
}

.prose li {
  margin-bottom: 0.4em;
}

.prose a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-color: rgba(193,68,14,0.35);
  text-underline-offset: 3px;
  transition: color 0.15s;
}

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

/* Inline code / mono values */
.prose code, code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 0.1em 0.35em;
  color: var(--accent-dark);
}

/* Binary values get special treatment */
.bin {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--accent-dark);
  background: var(--accent-light);
  border: 1px solid rgba(193,68,14,0.2);
  border-radius: 3px;
  padding: 0.05em 0.3em;
  font-size: 0.9em;
}

.dec {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--blue);
  background: var(--blue-light);
  border: 1px solid rgba(29,78,122,0.2);
  border-radius: 3px;
  padding: 0.05em 0.3em;
  font-size: 0.9em;
}

.hex {
  font-family: var(--font-mono);
  font-weight: 600;
  color: #1a6b4a;
  background: #e0f2ea;
  border: 1px solid rgba(26,107,74,0.22);
  border-radius: 3px;
  padding: 0.05em 0.3em;
  font-size: 0.9em;
}

.uni {
  font-family: var(--font-mono);
  font-weight: 600;
  color: #5b2d8e;
  background: #ede4f7;
  border: 1px solid rgba(91,45,142,0.22);
  border-radius: 3px;
  padding: 0.05em 0.3em;
  font-size: 0.9em;
}

/* ── Definition Callout ─────────────────────────────────────── */
.definition {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin: 28px 0;
}

.definition .def-term {
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent-dark);
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.definition .def-term::before {
  content: 'DEF';
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.1em;
  background: var(--accent);
  color: white;
  padding: 2px 6px;
  border-radius: 3px;
}

.definition p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--ink-mid);
}

/* ── Chapter Photo ──────────────────────────────────────────── */
.chapter-photo {
  margin: 36px 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 2px 10px rgba(26,24,20,0.07);
}
.chapter-photo img {
  width: 100%;
  height: auto;
  display: block;
  border-bottom: 1px solid var(--border);
}
.chapter-photo figcaption {
  padding: 12px 18px 14px;
  font-size: 0.8rem;
  color: var(--ink-mid);
  font-family: var(--font-body);
  line-height: 1.55;
}
.chapter-photo .photo-credit {
  display: block;
  margin-top: 5px;
  font-size: 0.73rem;
  color: var(--border-dark);
  font-style: italic;
}
.chapter-photo .photo-credit a {
  color: var(--ink-light);
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* ── Video Embed ────────────────────────────────────────────── */
.video-wrap {
  display: block;
  margin: 28px 0;
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 2px 10px rgba(26,24,20,0.07);
  text-decoration: none;
  transition: box-shadow 0.15s;
}
.video-wrap:hover {
  box-shadow: 0 4px 20px rgba(26,24,20,0.14);
}
.video-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  background: var(--ink);
}
.video-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #fff;
  background: var(--accent);
  padding: 1px 7px 2px;
  border-radius: 3px;
  flex-shrink: 0;
}
.video-title {
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  color: #F0EDE8;
}
.video-frame {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
}
.video-frame iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}
.video-body {
  background: #111;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px 24px;
  gap: 24px;
}
.video-play {
  width: 64px;
  height: 44px;
  background: #FF0000;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.video-watch {
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 600;
  color: white;
  margin-bottom: 6px;
}
.video-url {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: rgba(255,255,255,0.45);
}
.video-caption {
  padding: 10px 16px 12px;
  font-size: 0.8rem;
  color: var(--ink-mid);
  font-family: var(--font-body);
  line-height: 1.55;
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
}

/* ── Data Table ─────────────────────────────────────────────── */
.data-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin: 24px 0;
  font-family: var(--font-body);
  font-size: 0.875rem;
  box-shadow: 0 2px 8px rgba(26,24,20,0.06);
}
.data-table thead tr { background: var(--ink); }
.data-table thead th {
  padding: 10px 16px;
  text-align: left;
  font-size: 0.71rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #F0EDE8;
  border-right: 1px solid rgba(255,255,255,0.1);
  white-space: nowrap;
}
.data-table thead th:last-child { border-right: none; }
.data-table tbody tr { border-top: 1px solid var(--border); }
.data-table tbody tr:nth-child(odd)  { background: var(--bg-card); }
.data-table tbody tr:nth-child(even) { background: var(--bg-alt); }
.data-table tbody td {
  padding: 9px 16px;
  color: var(--ink-mid);
  border-right: 1px solid var(--border);
  border-top: 1px solid var(--border);
  vertical-align: middle;
  line-height: 1.4;
}
.data-table tbody td:last-child  { border-right: none; }
.data-table tbody td:first-child  { font-weight: 700; color: var(--ink); }

/* ── Note / Aside ───────────────────────────────────────────── */
.note {
  background: var(--blue-light);
  border: 1px solid rgba(29,78,122,0.2);
  border-left: 4px solid var(--blue);
  border-radius: var(--radius);
  padding: 18px 24px;
  margin: 28px 0;
  font-size: 0.92rem;
  color: var(--blue);
}

.note strong { color: var(--blue); }

/* ── Place Value Table ──────────────────────────────────────── */
.place-table {
  border-collapse: collapse;
  margin: 24px auto;
  font-family: var(--font-mono);
}

.place-table td, .place-table th {
  border: 1px solid var(--border-dark);
  padding: 10px 18px;
  text-align: center;
  min-width: 52px;
}

.place-table .row-digit td {
  font-size: 1.2rem;
  font-weight: 600;
  background: var(--bg-card);
  color: var(--ink);
}

.place-table .row-digit td.bit-1 {
  background: var(--accent-light);
  color: var(--accent-dark);
}

.place-table .row-place td {
  font-size: 0.78rem;
  background: var(--bg-alt);
  color: var(--ink-mid);
}

.place-table .row-power td {
  font-size: 0.72rem;
  background: var(--bg-alt);
  color: var(--ink-light);
}

/* ── Widget Card ────────────────────────────────────────────── */
.widget-card {
  background: var(--bg-card);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  margin: 40px 0;
  box-shadow: 0 2px 12px rgba(26,24,20,0.07), 0 1px 3px rgba(26,24,20,0.05);
  position: relative;
}

.widget-card::before {
  content: attr(data-widget-name);
  position: absolute;
  top: -1px; right: 20px;
  background: var(--accent);
  color: white;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 3px 10px;
  border-radius: 0 0 6px 6px;
}

.widget-title {
  font-family: var(--font-head);
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--ink);
}

.widget-desc {
  font-size: 0.88rem;
  color: var(--ink-light);
  margin-bottom: 20px;
}

/* ── Binary Converter Widget ────────────────────────────────── */
.converter-grid {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 16px;
  align-items: center;
}

.converter-side label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-light);
  margin-bottom: 6px;
}

.converter-side input {
  width: 100%;
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 600;
  padding: 12px 16px;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--ink);
  outline: none;
  transition: border-color 0.15s;
}

.converter-side input:focus {
  border-color: var(--accent);
}

.converter-side.binary input { color: var(--accent-dark); }
.converter-side.decimal input { color: var(--blue); }

.converter-arrow {
  font-size: 1.4rem;
  color: var(--border-dark);
  text-align: center;
  margin-top: 22px;
}

.converter-steps {
  margin-top: 20px;
  padding: 16px 18px;
  background: var(--bg-alt);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  line-height: 1.7;
  color: var(--ink-mid);
  min-height: 48px;
  border: 1px solid var(--border);
}

.converter-steps .step-line { display: block; }
.converter-steps .step-line.highlight { color: var(--accent-dark); font-weight: 600; }

.converter-error {
  color: #c0392b;
  font-size: 0.82rem;
  margin-top: 8px;
  font-family: var(--font-mono);
}

/* ── Quiz / Practice Problems ───────────────────────────────── */
.practice-block {
  background: var(--blue-light);
  border: 1px solid rgba(29,78,122,0.2);
  border-left: 4px solid var(--blue);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin: 40px 0;
}

.practice-block .practice-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
}

.practice-block .practice-label {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  background: var(--blue);
  color: white;
  padding: 3px 9px;
  border-radius: 3px;
}

.practice-block .practice-title {
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 700;
  color: var(--blue);
}

.quiz-question {
  margin-bottom: 20px;
  padding-bottom: 20px;
  border-bottom: 1px solid rgba(29,78,122,0.15);
}

.quiz-question:last-of-type { border-bottom: none; margin-bottom: 0; }

.quiz-question .q-text {
  font-size: 0.97rem;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 12px;
}

.quiz-question .q-input-row {
  display: flex;
  gap: 10px;
  align-items: center;
}

.quiz-question input[type="text"] {
  font-family: var(--font-mono);
  font-size: 1rem;
  padding: 8px 14px;
  border: 2px solid rgba(46,107,79,0.3);
  border-radius: var(--radius);
  background: white;
  color: var(--ink);
  outline: none;
  min-width: 160px;
  transition: border-color 0.15s;
}

.quiz-question input[type="text"]:focus {
  border-color: var(--green);
}

.btn {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 9px 18px;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.15s;
}

.btn-check {
  background: var(--green);
  color: white;
}

.btn-check:hover { background: #245940; }

.btn-accent {
  background: var(--accent);
  color: white;
}

.btn-accent:hover { background: var(--accent-dark); }

.btn-ghost {
  background: transparent;
  color: var(--ink-mid);
  border: 1px solid var(--border-dark);
}

.btn-ghost:hover { background: var(--bg-alt); }

.q-feedback {
  margin-top: 10px;
  font-size: 0.88rem;
  padding: 8px 14px;
  border-radius: var(--radius);
  font-family: var(--font-mono);
  display: none;
}

.q-feedback.correct {
  display: block;
  background: #d4edda;
  color: #155724;
  border: 1px solid #c3e6cb;
}

.q-feedback.incorrect {
  display: block;
  background: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
}

.q-feedback.hint {
  display: block;
  background: var(--blue-light);
  color: var(--blue);
  border: 1px solid rgba(29,78,122,0.2);
}

/* ── Chapter Nav Footer ─────────────────────────────────────── */
.chapter-nav-footer {
  width: 100%;
  max-width: var(--col-width);
  margin-top: 72px;
  padding-top: 32px;
  border-top: 2px solid var(--ink);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.chapter-nav-footer a {
  display: flex;
  flex-direction: column;
  gap: 4px;
  text-decoration: none;
  color: var(--ink);
  transition: color 0.15s;
}

.chapter-nav-footer a:hover { color: var(--accent); }

.chapter-nav-footer .nav-direction {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-light);
}

.chapter-nav-footer .nav-title {
  font-family: var(--font-head);
  font-size: 0.95rem;
  font-weight: 600;
}

.chapter-nav-footer a.next { text-align: right; }

/* ── Index / Landing Page ───────────────────────────────────── */
.index-hero {
  width: 100%;
  max-width: var(--col-width);
  padding: 80px 0 56px;
  border-bottom: 2px solid var(--ink);
  margin-bottom: 56px;
}

.index-hero .hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
}

.index-hero h1 {
  font-family: var(--font-head);
  font-size: 3.2rem;
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.025em;
  color: var(--ink);
  margin-bottom: 8px;
}

.index-hero .subtitle {
  font-family: var(--font-head);
  font-size: 1.35rem;
  font-weight: 300;
  color: var(--ink-mid);
  margin-bottom: 24px;
}

.index-hero .author-line {
  font-size: 0.88rem;
  color: var(--ink-light);
}

.index-hero .author-line strong {
  color: var(--ink-mid);
  font-weight: 600;
}

.unit-section {
  width: 100%;
  max-width: var(--col-width);
  margin-bottom: 48px;
}

.unit-label {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-light);
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

.chapter-card {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  padding: 18px 0;
  border-bottom: 1px solid var(--border);
  text-decoration: none;
  color: var(--ink);
  transition: all 0.15s;
}

.chapter-card:hover { color: var(--accent); }
.chapter-card:hover .card-num { color: var(--accent); border-color: var(--accent); }

.card-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--ink-light);
  border: 1px solid var(--border-dark);
  border-radius: 4px;
  padding: 4px 8px;
  flex-shrink: 0;
  margin-top: 2px;
  transition: all 0.15s;
  min-width: 44px;
  text-align: center;
}

.card-body .card-title {
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.3;
}

.card-body .card-desc {
  font-size: 0.83rem;
  color: var(--ink-light);
  margin-top: 4px;
  line-height: 1.4;
}

/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 900px) {
  :root { --sidebar-w: 0px; }

  .sidebar {
    width: 100%;
    min-height: auto;
    position: relative;
  }

  .site-wrapper { flex-direction: column; }
  .main-content { margin-left: 0; padding: 0 20px 60px; }
  .chapter-deco { display: none; }
  .converter-grid { grid-template-columns: 1fr; }
  .converter-arrow { transform: rotate(90deg); }
}

/* ── Multiple Choice ────────────────────────────────────────── */
.mc-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 12px;
}

.mc-option {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 10px 14px;
  background: white;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.15s;
  text-align: left;
  font-family: var(--font-body);
  font-size: 0.92rem;
  line-height: 1.45;
  color: var(--ink);
  width: 100%;
}

.mc-option:hover:not(:disabled) {
  border-color: var(--green);
  background: var(--green-light);
}

.mc-option .mc-letter {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  background: var(--bg-alt);
  border: 1px solid var(--border-dark);
  border-radius: 3px;
  padding: 2px 7px;
  flex-shrink: 0;
  margin-top: 1px;
  transition: all 0.15s;
  color: var(--ink-mid);
}

.mc-option:hover:not(:disabled) .mc-letter {
  background: var(--green);
  border-color: var(--green);
  color: white;
}

.mc-option.correct {
  border-color: var(--green);
  background: var(--green-light);
  cursor: default;
}

.mc-option.correct .mc-letter {
  background: var(--green);
  border-color: var(--green);
  color: white;
}

.mc-option.incorrect {
  border-color: #c0392b;
  background: #fdf0f0;
  cursor: default;
}

.mc-option.incorrect .mc-letter {
  background: #c0392b;
  border-color: #c0392b;
  color: white;
}

.mc-option.revealed {
  border-color: var(--green);
  background: var(--green-light);
  cursor: default;
  opacity: 0.75;
}

.mc-option:disabled {
  cursor: default;
}

.mc-feedback {
  margin-top: 10px;
  font-size: 0.88rem;
  padding: 8px 14px;
  border-radius: var(--radius);
  display: none;
  line-height: 1.5;
}

.mc-feedback.correct {
  display: block;
  background: #d4edda;
  color: #155724;
  border: 1px solid #c3e6cb;
}

.mc-feedback.incorrect {
  display: block;
  background: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
}

.mc-feedback.hint {
  display: block;
  background: var(--blue-light);
  color: var(--blue);
  border: 1px solid rgba(29,78,122,0.2);
}

/* ── Comparison Table ───────────────────────────────────────── */
.comparison-table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 0.88rem;
}

.comparison-table th {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: var(--ink);
  color: #fff;
  padding: 10px 14px;
  text-align: left;
  font-weight: 600;
}

.comparison-table td {
  padding: 11px 14px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
  line-height: 1.45;
  color: var(--ink-mid);
}

.comparison-table td strong {
  color: var(--ink);
}

.comparison-table tr:nth-child(even) td {
  background: var(--bg-alt);
}

.comparison-table tr:last-child td {
  border-bottom: none;
}

/* ── Shell Simulator Widget ─────────────────────────────────── */
.shell-sim {
  background: #1e1e1e;
  border-radius: var(--radius-lg);
  overflow: hidden;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  cursor: text;
  border: 1px solid #3a3a3a;
}

.shell-titlebar {
  background: #2d2d2d;
  padding: 8px 14px;
  display: flex;
  align-items: center;
  gap: 6px;
  border-bottom: 1px solid #3a3a3a;
}

.shell-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  display: inline-block;
  flex-shrink: 0;
}

.shell-title {
  margin-left: 8px;
  color: #888;
  font-size: 0.75rem;
  letter-spacing: 0.02em;
}

.shell-output {
  padding: 14px 18px 8px;
  min-height: 180px;
  max-height: 380px;
  overflow-y: auto;
  color: #d4d4d4;
  line-height: 1.55;
}

.shell-line {
  white-space: pre-wrap;
  word-break: break-all;
  min-height: 1em;
}

.shell-line.shell-echo   { color: #6cb6ff; }
.shell-line.shell-result { color: #d4d4d4; }
.shell-line.shell-info   { color: #666; font-style: italic; }

.shell-input-row {
  display: flex;
  align-items: center;
  padding: 6px 18px 10px;
  border-top: 1px solid #2d2d2d;
}

.shell-ps1 {
  color: #28c840;
  white-space: nowrap;
  flex-shrink: 0;
  user-select: none;
}

.shell-input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: #d4d4d4;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  caret-color: #28c840;
  min-width: 0;
}

/* ── Linux Permissions Widget ───────────────────────────────── */
.perm-widget {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.perm-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.perm-group {
  background: var(--bg-alt);
  border-radius: var(--radius);
  padding: 1rem 0.75rem;
  text-align: center;
}

.perm-group-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-mid);
  margin-bottom: 0.75rem;
}

.perm-toggles {
  display: flex;
  justify-content: center;
  gap: 6px;
  margin-bottom: 0.6rem;
}

.perm-btn {
  width: 36px;
  height: 36px;
  border-radius: 6px;
  border: 2px solid var(--border-dark);
  background: var(--bg-card);
  color: var(--ink-mid);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.1s, border-color 0.1s, color 0.1s;
}

.perm-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.perm-btn:not(.active):hover {
  border-color: var(--accent);
  color: var(--accent);
}

.perm-octal-val {
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--ink);
}

.perm-output {
  background: var(--bg-alt);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin-bottom: 1rem;
}

.perm-notations {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-bottom: 0.75rem;
}

.perm-notation {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.perm-label-sm {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--ink-light);
}

.perm-symbolic,
.perm-octal-code {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--accent);
  background: transparent;
  padding: 0;
}

.perm-desc {
  font-size: 0.88rem;
  color: var(--ink-mid);
  line-height: 1.55;
}

.perm-presets {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
}

.perm-presets-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-light);
}

.perm-preset {
  padding: 0.28rem 0.85rem;
  border-radius: 20px;
  border: 1px solid var(--border-dark);
  background: var(--bg-card);
  color: var(--ink-mid);
  font-size: 0.8rem;
  cursor: pointer;
  transition: border-color 0.1s, color 0.1s;
  font-family: var(--font-body);
}

.perm-preset:hover {
  border-color: var(--accent);
  color: var(--accent);
}

@media (max-width: 560px) {
  .perm-grid { grid-template-columns: 1fr; }
}

/* ── Filesystem Tree Widget ─────────────────────────────────── */
.fst-widget {
  display: grid;
  grid-template-columns: 220px 1fr;
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-lg);
  overflow: hidden;
  min-height: 300px;
}

.fst-tree-panel {
  background: #1e1e1e;
  padding: 10px 0;
  overflow-y: auto;
  max-height: 440px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  border-right: 1px solid #3a3a3a;
}

.fst-node { display: block; }

.fst-label {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 4px 14px;
  cursor: pointer;
  user-select: none;
  transition: background 0.1s;
}

.fst-label:hover  { background: #2a2a2a; }
.fst-label.active { background: #1d3d5c; }

.fst-toggle {
  font-size: 0.55rem;
  color: #666;
  width: 10px;
  flex-shrink: 0;
  line-height: 1;
}

.fst-name { color: #6cb6ff; font-size: 0.82rem; }
.fst-label.active .fst-name { color: #fff; }

.fst-detail {
  background: var(--bg-card);
  padding: 22px 24px;
}

.fst-detail-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
}

.fst-hint {
  color: var(--ink-light);
  font-size: 0.88rem;
  font-style: italic;
}

.fst-detail-path {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 10px;
}

.fst-detail-desc {
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--ink);
  margin-bottom: 14px;
}

.fst-detail-section {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink-light);
  margin-bottom: 6px;
}

.fst-detail-examples {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--green);
  background: var(--bg-alt);
  padding: 9px 13px;
  border-radius: var(--radius);
  line-height: 1.65;
}

@media (max-width: 580px) {
  .fst-widget { grid-template-columns: 1fr; grid-template-rows: auto auto; }
  .fst-tree-panel { max-height: 200px; border-right: none; border-bottom: 1px solid #3a3a3a; }
}

/* ── Layer Explorer widget ──────────────────────────────────── */
.le-widget { display:grid; grid-template-columns:188px 1fr; border:1px solid var(--border-dark); border-radius:var(--radius-lg); overflow:hidden; min-height:290px; }
.le-stack { background:#1e1e1e; padding:6px 0; }
.le-layer { display:flex; align-items:center; gap:10px; padding:13px 15px; cursor:pointer; border-left:4px solid transparent; }
.le-layer:hover { background:rgba(255,255,255,0.06); }
.le-layer.active { background:rgba(255,255,255,0.09); border-left-color:rgba(255,255,255,0.35); }
.le-num { width:22px; height:22px; border-radius:50%; display:flex; align-items:center; justify-content:center; font-size:10px; font-weight:700; flex-shrink:0; color:#fff; }
.le-layer-name { font-size:0.85rem; font-weight:600; color:#d4d4d4; }
.le-detail { background:var(--bg-card); padding:18px 22px; overflow-y:auto; }
.le-detail-placeholder { display:flex; align-items:center; justify-content:center; color:var(--ink-light); font-style:italic; font-size:0.88rem; }
.le-detail-header { margin-bottom:10px; }
.le-detail-title { font-size:1.05rem; font-weight:700; margin-bottom:5px; }
.le-detail-pdu { display:inline-block; padding:2px 10px; border-radius:12px; font-family:var(--font-mono); font-size:0.72rem; font-weight:600; }
.le-detail-role { font-size:0.88rem; color:var(--ink); line-height:1.6; margin:12px 0 4px; }
.le-detail-section { font-size:0.68rem; font-weight:700; text-transform:uppercase; letter-spacing:0.08em; color:var(--ink-light); margin:12px 0 3px; }
.le-detail-value { font-size:0.86rem; color:var(--ink-mid); line-height:1.5; }
.le-detail-example { font-size:0.84rem; font-style:italic; color:var(--ink-mid); background:var(--bg-alt); border-radius:var(--radius); padding:8px 12px; margin-top:6px; line-height:1.55; }
@media (max-width:540px) { .le-widget { grid-template-columns:1fr; } .le-stack { border-bottom:1px solid #3a3a3a; max-height:200px; overflow-y:auto; } }

/* ── DNS Records widget ─────────────────────────────────────── */
.dr-widget { display:grid; grid-template-columns:188px 1fr; border:1px solid var(--border-dark); border-radius:var(--radius-lg); overflow:hidden; min-height:290px; }
.dr-stack { background:#1e1e1e; padding:6px 0; }
.dr-item { display:flex; align-items:center; gap:10px; padding:11px 15px; cursor:pointer; border-left:4px solid transparent; }
.dr-item:hover { background:rgba(255,255,255,0.06); }
.dr-item.active { background:rgba(255,255,255,0.09); border-left-color:rgba(255,255,255,0.35); }
.dr-badge { min-width:46px; height:22px; border-radius:3px; display:flex; align-items:center; justify-content:center; font-family:var(--font-mono); font-size:0.72rem; font-weight:700; flex-shrink:0; color:#fff; padding:0 5px; }
.dr-name { font-size:0.82rem; font-weight:500; color:#b0b0b0; line-height:1.3; }
.dr-detail { background:var(--bg-card); padding:18px 22px; overflow-y:auto; }
.dr-placeholder { display:flex; align-items:center; justify-content:center; color:var(--ink-light); font-style:italic; font-size:0.88rem; }
.dr-detail-header { display:flex; align-items:baseline; gap:12px; margin-bottom:10px; }
.dr-detail-type { font-family:var(--font-mono); font-size:1.35rem; font-weight:700; line-height:1; }
.dr-detail-full { font-size:0.95rem; font-weight:600; color:var(--ink-mid); }
.dr-detail-purpose { font-size:0.88rem; color:var(--ink); line-height:1.6; margin:10px 0 4px; }
.dr-detail-section { font-size:0.68rem; font-weight:700; text-transform:uppercase; letter-spacing:0.08em; color:var(--ink-light); margin:12px 0 3px; }
.dr-detail-example { font-family:var(--font-mono); font-size:0.82rem; color:#4ec94e; background:#1a1a1a; border-radius:var(--radius); padding:10px 14px; margin-top:4px; line-height:1.6; white-space:pre; overflow-x:auto; }
.dr-detail-notes { font-size:0.85rem; font-style:italic; color:var(--ink-mid); background:var(--bg-alt); border-radius:var(--radius); padding:8px 12px; margin-top:4px; line-height:1.55; }
@media (max-width:540px) { .dr-widget { grid-template-columns:1fr; } .dr-stack { border-bottom:1px solid #3a3a3a; max-height:200px; overflow-y:auto; } }

/* ── Crypto Explorer widget ─────────────────────────────────── */
.cx-widget { display:flex; flex-direction:column; gap:20px; }
.cx-section { border:1px solid var(--border-dark); border-radius:var(--radius-lg); overflow:hidden; }
.cx-section-hd { background:#1e1e1e; padding:10px 18px; font-family:var(--font-mono); font-size:0.78rem; font-weight:700; color:#d4d4d4; letter-spacing:0.06em; text-transform:uppercase; }
.cx-section-bd { padding:18px 22px; background:var(--bg-card); }
.cx-row { display:flex; flex-direction:column; gap:5px; margin-bottom:12px; }
.cx-row label { font-size:0.72rem; font-weight:700; text-transform:uppercase; letter-spacing:0.07em; color:var(--ink-light); }
.cx-row input, .cx-row textarea { font-family:var(--font-body); font-size:0.88rem; padding:8px 12px; border:1px solid var(--border-dark); border-radius:var(--radius); background:var(--bg-alt); color:var(--ink); width:100%; box-sizing:border-box; }
.cx-row textarea { min-height:72px; resize:vertical; }
.cx-row input:focus, .cx-row textarea:focus { outline:2px solid var(--accent); outline-offset:1px; }
.cx-hash-output { font-family:var(--font-mono); font-size:0.82rem; padding:10px 14px; background:#0f1a0f; border-radius:var(--radius); margin-bottom:6px; min-height:38px; word-break:break-all; }
.cx-hash-value { color:#4ec94e; }
.cx-hash-placeholder { color:#555; font-style:italic; }
.cx-hash-meta { font-size:0.72rem; color:var(--ink-light); margin-bottom:16px; }
.cx-avalanche { margin-top:4px; }
.cx-av-label { font-size:0.72rem; font-weight:700; text-transform:uppercase; letter-spacing:0.07em; color:var(--ink-light); margin-bottom:8px; }
.cx-av-grid { display:grid; grid-template-columns:1fr 1fr; gap:10px; }
.cx-av-item { background:var(--bg-alt); border-radius:var(--radius); padding:10px 12px; }
.cx-av-input { font-size:0.85rem; font-weight:600; color:var(--ink); margin-bottom:6px; }
.cx-av-hash { font-family:var(--font-mono); font-size:0.7rem; color:#4ec94e; word-break:break-all; line-height:1.5; }
.cx-enc-grid { display:grid; grid-template-columns:1fr 1fr; gap:20px; }
.cx-btn { display:inline-flex; align-items:center; justify-content:center; padding:8px 18px; background:var(--accent); color:#fff; border:none; border-radius:var(--radius); font-family:var(--font-body); font-size:0.88rem; font-weight:600; cursor:pointer; margin-bottom:10px; }
.cx-btn:hover { background:#a83a0c; }
.cx-cipher-out, .cx-plain-out { font-family:var(--font-mono); font-size:0.72rem; padding:10px 12px; background:#0f1a0f; border-radius:var(--radius); word-break:break-all; min-height:44px; line-height:1.6; color:#4ec94e; margin-bottom:6px; }
.cx-plain-out { background:var(--bg-alt); color:var(--ink); }
.cx-enc-note { font-size:0.75rem; color:var(--ink-light); font-style:italic; line-height:1.5; }
.cx-error { color:#c14040; font-size:0.82rem; }
@media (max-width:600px) { .cx-enc-grid { grid-template-columns:1fr; } .cx-av-grid { grid-template-columns:1fr; } }

/* ── Cloud Responsibility widget ────────────────────────────── */
.cr-widget { }
.cr-tabs { display:flex; gap:8px; margin-bottom:16px; flex-wrap:wrap; }
.cr-tab { padding:7px 22px; border-radius:var(--radius); border:1.5px solid var(--border-dark); background:var(--bg-card); font-size:0.88rem; font-weight:600; font-family:var(--font-body); cursor:pointer; color:var(--ink-mid); transition:border-color 0.15s,color 0.15s,background 0.15s; }
.cr-tab:hover { border-color:var(--accent); color:var(--accent); }
.cr-tab.active { background:var(--accent); border-color:var(--accent); color:#fff; }
.cr-stack { display:flex; flex-direction:column; gap:5px; margin-bottom:14px; }
.cr-layer { display:flex; align-items:center; justify-content:space-between; padding:11px 16px; border-radius:var(--radius); cursor:pointer; transition:background 0.25s; user-select:none; border:1.5px solid transparent; }
.cr-layer[data-owner="provider"] { background:#1A2F5E; }
.cr-layer[data-owner="customer"] { background:var(--bg-alt); border-color:var(--border-dark); }
.cr-layer.selected { outline:2px solid var(--accent); outline-offset:2px; }
.cr-layer-label { font-weight:600; font-size:0.88rem; }
.cr-layer[data-owner="provider"] .cr-layer-label { color:#fff; }
.cr-layer[data-owner="customer"] .cr-layer-label { color:var(--ink); }
.cr-badge { font-size:0.68rem; font-weight:700; padding:2px 10px; border-radius:10px; white-space:nowrap; }
.cr-layer[data-owner="provider"] .cr-badge { background:rgba(255,255,255,0.15); color:#fff; }
.cr-layer[data-owner="customer"] .cr-badge { background:var(--accent); color:#fff; }
.cr-detail { background:var(--bg-card); border:1px solid var(--border); border-radius:var(--radius-lg); padding:16px 20px; }
.cr-placeholder { color:var(--ink-light); font-style:italic; font-size:0.88rem; display:flex; align-items:center; justify-content:center; min-height:64px; }
.cr-detail-layer { font-size:1rem; font-weight:700; color:var(--ink); margin-bottom:4px; }
.cr-detail-desc { font-size:0.86rem; color:var(--ink-mid); line-height:1.6; margin-bottom:10px; }
.cr-detail-owner-label { font-size:0.68rem; font-weight:700; text-transform:uppercase; letter-spacing:0.08em; color:var(--ink-light); margin-bottom:4px; }
.cr-detail-note { font-size:0.86rem; color:var(--ink); line-height:1.6; background:var(--bg-alt); border-radius:var(--radius); padding:10px 14px; }
.cr-legend { display:flex; gap:18px; margin-top:12px; flex-wrap:wrap; }
.cr-legend-item { display:flex; align-items:center; gap:7px; font-size:0.78rem; color:var(--ink-mid); }
.cr-legend-swatch { width:14px; height:14px; border-radius:3px; flex-shrink:0; }

/* ── Network Topology widget ────────────────────────────────── */
.nt-widget { display:flex; flex-direction:column; gap:16px; }
.nt-diagram { display:flex; justify-content:center; }
.nt-node { cursor:pointer; }
.nt-node:hover .nd-bg { opacity:0.85; }
.nt-detail { background:var(--bg-card); border:1px solid var(--border); border-radius:var(--radius-lg); padding:18px 22px; }
.nt-placeholder { display:flex; align-items:center; justify-content:center; color:var(--ink-light); font-style:italic; font-size:0.88rem; min-height:80px; }
.nt-detail-header { display:flex; align-items:baseline; gap:12px; margin-bottom:10px; flex-wrap:wrap; }
.nt-detail-title { font-size:1.05rem; font-weight:700; }
.nt-detail-role { font-size:0.88rem; color:var(--ink); line-height:1.6; margin-bottom:4px; }
.nt-detail-section { font-size:0.68rem; font-weight:700; text-transform:uppercase; letter-spacing:0.08em; color:var(--ink-light); margin:12px 0 3px; }
.nt-detail-value { font-size:0.86rem; color:var(--ink-mid); line-height:1.5; }
.nt-detail-examples { font-size:0.84rem; font-style:italic; color:var(--ink-mid); background:var(--bg-alt); border-radius:var(--radius); padding:8px 12px; margin-top:6px; line-height:1.55; }

/* ── Journey Map widget ─────────────────────────────────────── */
.jm-widget { display:flex; flex-direction:column; gap:16px; }
.jm-flow { display:flex; align-items:center; overflow-x:auto; padding-bottom:6px; }
.jm-node { display:flex; flex-direction:column; align-items:center; cursor:pointer; flex-shrink:0; }
.jm-node-box { width:62px; height:52px; border-radius:var(--radius); border:2px solid var(--border-dark); background:var(--bg-card); display:flex; flex-direction:column; align-items:center; justify-content:center; gap:3px; transition:border-color 0.15s,background 0.15s; padding:4px; box-sizing:border-box; }
.jm-node-abbr { font-family:var(--font-mono); font-size:0.78rem; font-weight:700; color:var(--ink-mid); line-height:1; }
.jm-node-label { font-size:0.58rem; font-weight:600; text-transform:uppercase; letter-spacing:0.04em; color:var(--ink-light); text-align:center; line-height:1.2; }
.jm-node:hover .jm-node-box { border-color:var(--accent); background:rgba(193,68,14,0.06); }
.jm-node.active .jm-node-box { border-color:var(--accent); background:rgba(193,68,14,0.1); }
.jm-node.active .jm-node-abbr { color:var(--accent); }
.jm-arrow { color:var(--ink-light); font-size:0.9rem; padding:0 5px; flex-shrink:0; user-select:none; line-height:52px; }
.jm-detail { background:var(--bg-card); border:1px solid var(--border); border-radius:var(--radius-lg); padding:18px 22px; min-height:88px; }
.jm-placeholder { color:var(--ink-light); font-style:italic; font-size:0.88rem; display:flex; align-items:center; justify-content:center; min-height:52px; }
.jm-detail-title { font-size:1rem; font-weight:700; color:var(--ink); margin-bottom:8px; }
.jm-detail-chapters { display:flex; gap:6px; flex-wrap:wrap; margin-bottom:10px; }
.jm-detail-ch { font-family:var(--font-mono); font-size:0.72rem; font-weight:700; padding:2px 10px; border-radius:10px; background:var(--accent); color:#fff; }
.jm-detail-desc { font-size:0.88rem; color:var(--ink); line-height:1.65; }

/* ── Utility ────────────────────────────────────────────────── */
.mt-0 { margin-top: 0; }
.text-center { text-align: center; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); }