:root {
    --paper: #EFEAE0;
    --paper-2: #FFFDF8;
    --paper-card: #FFFFFF;
    --ink: #221D17;
    --ink-soft: #5B5145;
    --ink-muted: #84796B;
    --line: #DBD3C1;
    --line-subtle: #E8E2D5;
    --espresso: #3C2A1E;
    --ember: #C85A28;
    --ember-soft: #F4E2D5;
    --moss: #3E5B42;
    --moss-soft: #D7E3D3;
    --gold: #B4862F;
    --gold-soft: #F9F1DF;
    --unah-blue: #0E3866;
    --unah-blue-soft: #E5EEF8;
    
    /* Code Highlighting Palette */
    --code-bg: #121417;
    --code-header-bg: #1A1D23;
    --code-border: #2B313A;
    --code-text: #E6EDF3;
    --code-kw: #FF7B72;
    --code-type: #79C0FF;
    --code-str: #A5D6FF;
    --code-num: #FFA657;
    --code-comment: #8B949E;
    --code-fn: #D2A8FF;
    --code-esc: #7EE787;

    --shadow: 0 2px 8px rgba(34, 29, 23, 0.06);
    --shadow-md: 0 6px 16px rgba(34, 29, 23, 0.08);
    --sidebar-w: 300px;
    --transition-speed: 0.28s;
  }

  [data-theme="dark"] {
    --paper: #15181C;
    --paper-2: #1C2128;
    --paper-card: #22272E;
    --ink: #F0F6FC;
    --ink-soft: #ADBAC7;
    --ink-muted: #768390;
    --line: #373E47;
    --line-subtle: #2D333B;
    --espresso: #EFE6D6;
    --ember: #F0883E;
    --ember-soft: #382417;
    --moss: #7CE38B;
    --moss-soft: #1E3324;
    --gold: #E3B341;
    --gold-soft: #332B19;
    --unah-blue: #539BF5;
    --unah-blue-soft: #14253D;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
  }

  * { box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  body {
    margin: 0;
    padding: 0;
    background: var(--paper);
    color: var(--ink);
    font-family: "Work Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
  }

  h1, h2, h3, h4 {
    font-family: "Fraunces", "Georgia", serif;
    font-weight: 600;
    line-height: 1.25;
    margin: 0;
    color: var(--ink);
  }
  p { margin: 0 0 14px 0; }
  p:last-child { margin-bottom: 0; }
  a { color: var(--ember); text-decoration: none; }
  a:hover { text-decoration: underline; }
  .mono { font-family: "IBM Plex Mono", Consolas, monospace; }

  /* APP SHELL & SIDEBAR */
  .app-layout {
    display: flex;
    min-height: 100vh;
    position: relative;
    transition: all var(--transition-speed) ease;
  }

  .sidebar-toggle-btn {
    position: fixed;
    bottom: 24px;
    left: 24px;
    z-index: 100;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--espresso);
    color: var(--paper-2);
    border: 1px solid var(--line);
    box-shadow: 0 4px 14px rgba(0,0,0,0.25);
    padding: 10px 16px;
    border-radius: 30px;
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.8rem;
    cursor: pointer;
    transition: transform 0.2s ease, background 0.2s ease;
  }
  .sidebar-toggle-btn:hover {
    transform: translateY(-2px);
    background: var(--ember);
  }
  .sidebar-toggle-btn svg { width: 18px; height: 18px; stroke: currentColor; fill: none; stroke-width: 2; }

  aside.sidebar {
    width: var(--sidebar-w);
    min-width: var(--sidebar-w);
    height: 100vh;
    position: sticky;
    top: 0;
    background: var(--paper-2);
    border-right: 1px solid var(--line);
    display: flex;
    flex-direction: column;
    z-index: 50;
    transition: margin-left var(--transition-speed) cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow var(--transition-speed) ease;
    overflow-y: auto;
  }

  body.sidebar-collapsed aside.sidebar {
    margin-left: calc(-1 * var(--sidebar-w));
  }

  .sidebar-header {
    padding: 20px 18px 16px;
    border-bottom: 1px solid var(--line);
    background: var(--paper-2);
    position: sticky;
    top: 0;
    z-index: 2;
  }
  .univ-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: var(--gold-soft);
    color: var(--gold);
    border: 1px solid var(--gold);
    border-radius: 4px;
    padding: 3px 8px;
    font-size: 0.65rem;
    font-family: "IBM Plex Mono", monospace;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    margin-bottom: 8px;
  }
  .brand-title {
    font-family: "Fraunces", serif;
    font-size: 1.15rem;
    font-weight: 700;
    line-height: 1.2;
    color: var(--ink);
  }
  .brand-sub {
    font-size: 0.76rem;
    color: var(--ink-soft);
    margin-top: 4px;
  }
  .teacher-chip {
    margin-top: 10px;
    padding: 6px 10px;
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: 6px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.75rem;
  }
  .teacher-chip .avatar {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--unah-blue);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.7rem;
  }
  .teacher-chip .info { line-height: 1.2; }
  .teacher-chip .info .role { font-size: 0.65rem; color: var(--ink-muted); text-transform: uppercase; font-family: "IBM Plex Mono", monospace; }
  .teacher-chip .info .name { font-weight: 600; color: var(--ink); }

  .sidebar-nav {
    padding: 16px 12px 50px;
    display: flex;
    flex-direction: column;
    gap: 14px;
  }
  .nav-group-title {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--gold);
    padding-left: 8px;
    margin-bottom: 6px;
    font-weight: 600;
  }
  .module-group {
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: 10px;
    overflow: hidden;
  }
  .module-group-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 12px;
    font-weight: 600;
    font-size: 0.82rem;
    background: var(--paper-2);
    border-bottom: 1px solid var(--line-subtle);
  }
  .module-badge {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.65rem;
    color: var(--ember);
    background: var(--ember-soft);
    padding: 2px 6px;
    border-radius: 4px;
    margin-right: 6px;
  }
  .module-group ul {
    list-style: none;
    margin: 0;
    padding: 6px 6px;
    display: flex;
    flex-direction: column;
    gap: 2px;
  }
  .module-group li a {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 10px;
    border-radius: 6px;
    font-size: 0.77rem;
    color: var(--ink-soft);
    transition: all 0.15s ease;
  }
  .module-group li a:hover {
    background: var(--paper-card);
    color: var(--ink);
    text-decoration: none;
  }
  .module-group li a.active {
    background: var(--ember);
    color: #ffffff !important;
    font-weight: 600;
  }
  .module-group li a .dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--ink-muted);
    flex-shrink: 0;
  }
  .module-group li a.active .dot { background: #fff; }

  .sidebar-footer {
    margin-top: auto;
    padding: 14px 18px;
    border-top: 1px solid var(--line);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--paper-2);
    font-size: 0.75rem;
    font-family: "IBM Plex Mono", monospace;
  }
  .theme-btn {
    background: none;
    border: 1px solid var(--line);
    padding: 4px 10px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.78rem;
    color: var(--ink);
    display: flex;
    align-items: center;
    gap: 6px;
  }

  /* CONTENT AREA */
  .content-area {
    flex: 1;
    min-width: 0;
    max-width: 100%;
    display: flex;
    flex-direction: column;
  }

  .top-bar {
    position: sticky;
    top: 0;
    z-index: 40;
    background: var(--paper);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--line);
    padding: 12px 36px;
    display: flex;
    align-items: center;
    justify-content: space-between;
  }
  @media (max-width: 768px) {
    .top-bar { padding: 12px 18px; }
  }
  .bar-meta {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.74rem;
    color: var(--ink-soft);
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
  }
  .badge-tag {
    padding: 2px 8px;
    border-radius: 4px;
    background: var(--moss-soft);
    color: var(--moss);
    font-weight: 600;
  }
  .badge-unah {
    padding: 2px 8px;
    border-radius: 4px;
    background: var(--unah-blue-soft);
    color: var(--unah-blue);
    font-weight: 600;
  }

  main {
    max-width: 980px;
    margin-inline: auto;
    padding: 24px 36px 120px;
    width: 100%;
  }
  @media (max-width: 768px) {
    main { padding: 18px 16px 100px; }
  }

  section {
    padding-block: 52px;
    border-bottom: 1px solid var(--line);
    scroll-margin-top: 80px;
  }
  section:last-of-type { border-bottom: none; }

  .eyebrow {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.74rem;
    letter-spacing: 0.08em;
    color: var(--gold);
    text-transform: uppercase;
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 12px;
  }
  .eyebrow .n {
    background: var(--espresso);
    color: #fff;
    border-radius: 4px;
    padding: 2px 7px;
    font-size: 0.7rem;
  }
  .section-badge-mod {
    background: var(--ember);
    color: #fff;
    border-radius: 4px;
    padding: 2px 8px;
    font-size: 0.72rem;
    font-family: "IBM Plex Mono", monospace;
  }

  h2 { font-size: clamp(1.6rem, 1.2rem + 1.8vw, 2.3rem); margin-bottom: 14px; }
  h3 { font-size: 1.25rem; margin-top: 26px; margin-bottom: 12px; }
  h4 { font-size: 1.05rem; margin-top: 18px; margin-bottom: 8px; }
  .lede { font-size: 1.08rem; color: var(--ink-soft); max-width: 70ch; margin-bottom: 26px; line-height: 1.65; }

  /* Banners & Cards */
  .sub-module-banner {
    display: flex;
    align-items: center;
    gap: 14px;
    background: var(--paper-2);
    border-left: 4px solid var(--ember);
    border-top: 1px solid var(--line);
    border-right: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    border-radius: 0 10px 10px 0;
    padding: 16px 20px;
    margin-top: 36px;
    margin-bottom: 22px;
  }
  .sub-icon {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    background: var(--ember-soft);
    color: var(--ember);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    flex-shrink: 0;
  }
  .sub-info h3 { margin: 0; font-size: 1.15rem; }
  .sub-info span { font-size: 0.78rem; font-family: "IBM Plex Mono", monospace; color: var(--ink-soft); }

  .pedagogical-box {
    background: var(--paper-card);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 22px;
    margin-block: 22px;
    box-shadow: var(--shadow);
  }
  .pedagogical-box.rule {
    border-left: 5px solid var(--ember);
    background: var(--paper-2);
  }
  .pedagogical-box.tip {
    border-left: 5px solid var(--moss);
    background: var(--paper-2);
  }
  .pedagogical-box.warning {
    border-left: 5px solid #d9534f;
    background: var(--paper-2);
  }
  .pedagogical-box.unah {
    border-left: 5px solid var(--unah-blue);
    background: var(--paper-2);
  }
  .box-title {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 10px;
  }
  .pedagogical-box.rule .box-title { color: var(--ember); }
  .pedagogical-box.tip .box-title { color: var(--moss); }
  .pedagogical-box.warning .box-title { color: #d9534f; }
  .pedagogical-box.unah .box-title { color: var(--unah-blue); }

  /* Tables */
  .table-wrapper {
    overflow-x: auto;
    margin-block: 22px;
    border-radius: 10px;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
  }
  table.content-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--paper-card);
    font-size: 0.88rem;
    text-align: left;
  }
  table.content-table th {
    background: var(--paper-2);
    color: var(--espresso);
    padding: 12px 16px;
    border-bottom: 2px solid var(--line);
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.76rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }
  table.content-table td {
    padding: 12px 16px;
    border-bottom: 1px solid var(--line-subtle);
    color: var(--ink);
  }
  table.content-table tr:last-child td { border-bottom: none; }
  table.content-table tr:hover td { background: var(--paper-2); }
  table.content-table code {
    background: var(--paper);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.82rem;
    color: var(--ember);
    border: 1px solid var(--line);
  }

  /* Grid Layouts */
  .grid-2 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 16px;
    margin-block: 20px;
  }
  .grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 16px;
    margin-block: 20px;
  }
  .card-concept {
    background: var(--paper-card);
    border: 1px solid var(--line);
    border-radius: 10px;
    padding: 18px;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 8px;
  }
  .card-concept .concept-badge {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.68rem;
    color: var(--gold);
    text-transform: uppercase;
    font-weight: 600;
  }
  .card-concept h4 { margin: 0; font-size: 1.08rem; }
  .card-concept p { font-size: 0.88rem; color: var(--ink-soft); }

  /* CODE CONTAINERS */
  .code-container {
    background: var(--code-bg);
    border: 1px solid var(--code-border);
    border-radius: 12px;
    margin-block: 20px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  }
  .code-header {
    background: var(--code-header-bg);
    padding: 10px 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--code-border);
  }
  .code-filename {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.78rem;
    color: #A0AEC0;
    display: flex;
    align-items: center;
    gap: 8px;
  }
  .code-filename .file-icon { color: var(--ember); font-size: 0.95rem; }
  .copy-btn {
    background: transparent;
    border: 1px solid #3E4652;
    color: #C9D1D9;
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 0.72rem;
    font-family: "IBM Plex Mono", monospace;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 5px;
    transition: all 0.2s;
  }
  .copy-btn:hover {
    background: #2D333B;
    border-color: #58A6FF;
    color: #58A6FF;
  }
  pre.code-content {
    margin: 0;
    padding: 18px 20px;
    font-family: "IBM Plex Mono", Consolas, Menlo, monospace;
    font-size: 0.84rem;
    line-height: 1.65;
    color: var(--code-text);
    overflow-x: auto;
    background: var(--code-bg);
  }
  pre.code-content code {
    font-family: inherit;
    background: transparent !important;
    padding: 0 !important;
    border: none !important;
  }
  .j-kw { color: var(--code-kw); font-weight: 600; }
  .j-type { color: var(--code-type); font-weight: 500; }
  .j-fn { color: var(--code-fn); }
  .j-str { color: var(--code-str); }
  .j-num { color: var(--code-num); }
  .j-com { color: var(--code-comment); font-style: italic; }
  .j-esc { color: var(--code-esc); font-weight: bold; }

  /* HERO HEADER */
  .hero-header {
    padding: 36px 0 24px;
  }
  .docente-banner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--paper-2);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 18px 22px;
    margin-bottom: 30px;
    gap: 16px;
    flex-wrap: wrap;
  }
  .docente-meta-left { display: flex; align-items: center; gap: 14px; }
  .docente-badge-icon {
    width: 48px;
    height: 48px;
    background: var(--espresso);
    color: var(--paper-2);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
  }
  .docente-text-name { font-size: 1rem; font-weight: 700; color: var(--ink); }
  .docente-text-dept { font-size: 0.78rem; color: var(--ink-soft); font-family: "IBM Plex Mono", monospace; }
  .docente-badges-right { display: flex; gap: 8px; flex-wrap: wrap; }
  .pill-badge {
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.72rem;
    font-family: "IBM Plex Mono", monospace;
    font-weight: 600;
  }
  .pill-unah { background: var(--unah-blue-soft); color: var(--unah-blue); border: 1px solid var(--unah-blue); }
  .pill-term { background: var(--gold-soft); color: var(--gold); border: 1px solid var(--gold); }

  /* INTERACTIVE QUIZ & CLASSIFIER */
  .interactive-container {
    background: var(--paper-card);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 24px;
    margin-block: 26px;
    box-shadow: var(--shadow);
  }
  .quiz-option {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--paper-2);
    border: 1px solid var(--line);
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 10px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.9rem;
  }
  .quiz-option:hover {
    border-color: var(--ember);
    background: var(--paper);
  }
  .quiz-option.correct {
    border-color: var(--moss);
    background: var(--moss-soft);
    color: var(--moss);
    font-weight: 600;
  }
  .quiz-option.wrong {
    border-color: #d9534f;
    background: #fdf2f2;
    color: #b91c1c;
    font-weight: 600;
  }

  .interactive-classify-item {
    background: var(--paper-2);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 14px 18px;
    margin-bottom: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
  }
  .classify-buttons {
    display: flex;
    gap: 8px;
  }
  .btn-choice {
    padding: 6px 14px;
    border-radius: 6px;
    border: 1px solid var(--line);
    background: var(--paper-card);
    color: var(--ink);
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
  }
  .btn-choice:hover {
    border-color: var(--ember);
    color: var(--ember);
  }
  .btn-choice.selected-correct {
    background: var(--moss);
    border-color: var(--moss);
    color: #fff;
  }
  .btn-choice.selected-wrong {
    background: #d9534f;
    border-color: #d9534f;
    color: #fff;
  }

  /* DETAILS ACCORDION */
  details.hint-accordion {
    background: var(--paper-2);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 12px 16px;
    margin-top: 14px;
    font-size: 0.88rem;
  }
  details.hint-accordion summary {
    cursor: pointer;
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.8rem;
    color: var(--ember);
    font-weight: 600;
  }
  details.hint-accordion .hint-body {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px dashed var(--line);
    color: var(--ink-soft);
  }

  .mark-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--espresso);
    color: var(--paper-2);
    border: none;
    border-radius: 8px;
    padding: 10px 18px;
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.82rem;
    font-weight: 600;
    cursor: pointer;
    margin-top: 20px;
    transition: background 0.2s ease, transform 0.15s ease;
  }
  .mark-btn:hover { background: var(--ember); transform: translateY(-1px); }
  .mark-btn.done { background: var(--moss); color: #fff; }

  /* TIMELINE COMPONENT */
  .timeline {
    position: relative;
    padding-left: 28px;
    margin-block: 26px;
    border-left: 2px solid var(--line);
  }
  .timeline-item {
    position: relative;
    margin-bottom: 26px;
  }
  .timeline-item:last-child { margin-bottom: 0; }
  .timeline-dot {
    position: absolute;
    left: -35px;
    top: 4px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--ember);
    border: 2px solid var(--paper);
  }
  .timeline-year {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.74rem;
    font-weight: 600;
    color: var(--ember);
    text-transform: uppercase;
  }
  .timeline-content h4 { margin: 4px 0 6px 0; }

  footer {
    border-top: 1px solid var(--line);
    padding: 30px 36px;
    text-align: center;
    font-size: 0.82rem;
    color: var(--ink-soft);
    background: var(--paper-2);
    font-family: "IBM Plex Mono", monospace;
  }

  /* EJERCICIOS DE AUTOEVALUACIÓN */
  .exercise-card {
    border-top: 1px dashed var(--line);
    padding-top: 16px;
    margin-top: 16px;
  }
  .box-title + .exercise-card { border-top: none; margin-top: 0; padding-top: 0; }
  .exercise-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 12px;
  }
  .exercise-title { font-weight: 600; color: var(--ink); }
  .difficulty-badge {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.68rem;
    font-weight: 600;
    text-transform: uppercase;
    padding: 3px 8px;
    border-radius: 12px;
    white-space: nowrap;
  }
  .diff-basico { background: var(--moss-soft); color: var(--moss); }
  .diff-intermedio { background: var(--gold-soft); color: var(--gold); }
  .hint-body .code-container { margin-block: 6px 0; }

  /* MÓDULO 03 · BLOQUES DE CÓDIGO OCULTOS POR DEFECTO */
  .grid-2 > .code-collapsible { align-self: start; }
  .code-actions { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
  .code-collapsible.is-collapsed pre.code-content { display: none; }
  .code-collapsible.is-collapsed .copy-btn { display: none; }
  .code-collapsible.is-collapsed .code-header { border-bottom: none; }
  .code-toggle-btn, .code-toggle-all-btn {
    border-radius: 6px;
    font-family: "IBM Plex Mono", monospace;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
  }
  .code-toggle-btn {
    background: var(--ember);
    border: 1px solid var(--ember);
    color: #fff;
    padding: 4px 10px;
    font-size: 0.72rem;
  }
  .code-toggle-btn:hover { filter: brightness(1.1); }
  .code-toggle-btn[aria-expanded="true"] {
    background: transparent;
    border-color: #3E4652;
    color: #C9D1D9;
  }
  .code-toggle-all-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    flex-wrap: wrap;
    background: var(--paper-2);
    border: 1px dashed var(--line);
    border-radius: 10px;
    padding: 12px 16px;
    margin-block: 18px;
    font-size: 0.88rem;
    color: var(--ink-soft);
  }
  .code-toggle-all-btn {
    background: var(--espresso);
    border: none;
    color: var(--paper-2);
    padding: 8px 14px;
    font-size: 0.78rem;
  }
  .code-toggle-all-btn:hover { background: var(--ember); }

  /* ===== SITIO MULTIPÁGINA ===== */
  .home-link {
    display: block;
    margin: 0 4px 14px;
    padding: 10px 12px;
    border-radius: 8px;
    border: 1px solid var(--line);
    background: var(--paper-card);
    color: var(--ink);
    font-weight: 600;
    font-size: 0.86rem;
  }
  .home-link:hover, .home-link.current { border-color: var(--ember); color: var(--ember); }
  a.module-group-header { color: var(--ink); text-decoration: none; }
  a.module-group-header:hover { color: var(--ember); }
  .module-group.current { border-color: var(--ember); box-shadow: 0 0 0 1px var(--ember); }
  /* Solo se despliegan los temas del módulo que se está viendo */
  .sidebar-nav .module-group:not(.current) ul { display: none; }
  .sidebar-nav .module-group:not(.current) .module-group-header { border-bottom: none; }

  .module-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 16px;
    margin-block: 20px;
  }
  .module-card {
    display: flex;
    flex-direction: column;
    gap: 8px;
    background: var(--paper-card);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow);
    color: var(--ink);
    text-decoration: none;
    transition: transform 0.15s ease, border-color 0.2s ease;
  }
  .module-card:hover { transform: translateY(-2px); border-color: var(--ember); }
  .module-card h4 { margin: 0; font-size: 1.1rem; }
  .module-card p { font-size: 0.88rem; color: var(--ink-soft); flex: 1; }
  .module-card-top { display: flex; justify-content: space-between; align-items: center; }
  .module-card-done {
    display: none;
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--moss);
    background: var(--moss-soft);
    padding: 2px 8px;
    border-radius: 10px;
  }
  .module-card.done .module-card-done { display: inline-block; }
  .module-card-cta { font-family: "IBM Plex Mono", monospace; font-size: 0.78rem; font-weight: 600; color: var(--ember); }

  .page-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-top: 48px;
    padding-top: 24px;
    border-top: 1px solid var(--line);
  }
  .page-nav-link {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding: 16px 18px;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: var(--paper-card);
    color: var(--ink);
    text-decoration: none;
    transition: border-color 0.2s ease;
  }
  .page-nav-link:hover { border-color: var(--ember); }
  .page-nav-link span { font-family: "IBM Plex Mono", monospace; font-size: 0.74rem; color: var(--ember); font-weight: 600; }
  .page-nav-link.next { text-align: right; }
  @media (max-width: 600px) { .page-nav { grid-template-columns: 1fr; } }