/* ============================================
   Aprende HTML y CSS desde cero
   Hoja de estilos compartida por todo el curso
   ============================================ */

:root {
  --color-bg: #faf8f5;
  --color-bg-alt: #ffffff;
  --color-text: #2b2620;
  --color-text-soft: #5b5346;
  --color-primary: #d9622b;
  --color-primary-dark: #b74e1e;
  --color-primary-light: #ffe7d6;
  --color-accent: #2b6e63;
  --color-accent-light: #e2f2ee;
  --color-border: #e7e0d6;
  --color-code-bg: #2b2620;
  --color-code-text: #f5efe6;
  --color-warning-bg: #fff3cd;
  --color-warning-border: #f0c766;
  --color-group-a: var(--color-primary);
  --color-group-a-light: var(--color-primary-light);
  --color-group-b: var(--color-accent);
  --color-group-b-light: var(--color-accent-light);
  --color-group-c: #c23b7a;
  --color-group-c-light: #fbe3ef;
  --color-group-d: #6a4fc0;
  --color-group-d-light: #ece5fb;
  --sidebar-width: 280px;
  --radius: 14px;
  --shadow: 0 4px 16px rgba(43, 38, 32, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-bg: #1c1a17;
    --color-bg-alt: #262320;
    --color-text: #f1ece3;
    --color-text-soft: #c8bfae;
    --color-primary: #f38a4e;
    --color-primary-dark: #ffab72;
    --color-primary-light: #3a2a1c;
    --color-accent: #6fc4b3;
    --color-accent-light: #1f322e;
    --color-border: #3a352d;
    --color-code-bg: #100f0d;
    --color-code-text: #f1ece3;
    --color-warning-bg: #3a3319;
    --color-warning-border: #9c853a;
    --color-group-a: var(--color-primary);
    --color-group-a-light: var(--color-primary-light);
    --color-group-b: var(--color-accent);
    --color-group-b-light: var(--color-accent-light);
    --color-group-c: #f0a8cf;
    --color-group-c-light: #3a2030;
    --color-group-d: #b3a0f2;
    --color-group-d-light: #2a2245;
  }
}

:root[data-theme="dark"] {
  --color-bg: #1c1a17;
  --color-bg-alt: #262320;
  --color-text: #f1ece3;
  --color-text-soft: #c8bfae;
  --color-primary: #f38a4e;
  --color-primary-dark: #ffab72;
  --color-primary-light: #3a2a1c;
  --color-accent: #6fc4b3;
  --color-accent-light: #1f322e;
  --color-border: #3a352d;
  --color-code-bg: #100f0d;
  --color-code-text: #f1ece3;
  --color-warning-bg: #3a3319;
  --color-warning-border: #9c853a;
  --color-group-a: var(--color-primary);
  --color-group-a-light: var(--color-primary-light);
  --color-group-b: var(--color-accent);
  --color-group-b-light: var(--color-accent-light);
  --color-group-c: #f0a8cf;
  --color-group-c-light: #3a2030;
  --color-group-d: #b3a0f2;
  --color-group-d-light: #2a2245;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

html, body {
  overflow-x: hidden;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: "Trebuchet MS", "Segoe UI", Verdana, sans-serif;
  line-height: 1.65;
}

h1, h2, h3, h4 {
  font-family: Georgia, "Times New Roman", serif;
  line-height: 1.25;
  color: var(--color-text);
}

a {
  color: var(--color-primary-dark);
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--color-primary);
  color: #fff;
  padding: 0.6rem 1rem;
  z-index: 999;
}
.skip-link:focus {
  left: 0.5rem;
  top: 0.5rem;
}

/* ---------- Layout general con barra lateral ---------- */

.app-shell {
  display: flex;
  min-height: 100vh;
}

.topbar {
  display: none;
  align-items: center;
  justify-content: space-between;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
  padding: 0.8rem 1rem;
  position: sticky;
  top: 0;
  z-index: 20;
}

.topbar .brand {
  font-weight: bold;
  color: var(--color-primary-dark);
  text-decoration: none;
  font-size: 1.05rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 0;
}

.menu-toggle {
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text);
  border-radius: 8px;
  padding: 0.4rem 0.7rem;
  font-size: 1.1rem;
  cursor: pointer;
  flex-shrink: 0;
}

.sidebar {
  width: var(--sidebar-width);
  flex-shrink: 0;
  background: var(--color-bg-alt);
  border-right: 1px solid var(--color-border);
  padding: 1.5rem 1.2rem 3rem;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.sidebar .brand {
  display: block;
  text-decoration: none;
  font-size: 1.2rem;
  font-weight: bold;
  color: var(--color-primary-dark);
  margin-bottom: 0.2rem;
}

.sidebar .brand-sub {
  display: block;
  color: var(--color-text-soft);
  font-size: 0.85rem;
  margin-bottom: 1.6rem;
}

.nav-group-title {
  text-transform: uppercase;
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--color-text-soft);
  margin: 1.3rem 0 0.5rem;
  font-weight: bold;
}

.nav-group-title--a { color: var(--color-group-a); }
.nav-group-title--b { color: var(--color-group-b); }
.nav-group-title--c { color: var(--color-group-c); }
.nav-group-title--d { color: var(--color-group-d); }

.sidebar nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.sidebar nav li {
  margin-bottom: 0.15rem;
}

.sidebar nav a {
  display: flex;
  gap: 0.55rem;
  align-items: baseline;
  text-decoration: none;
  color: var(--color-text);
  padding: 0.45rem 0.6rem;
  border-radius: 10px;
  font-size: 0.93rem;
}

.sidebar nav a .num {
  color: var(--color-text-soft);
  font-variant-numeric: tabular-nums;
  font-size: 0.8rem;
  min-width: 1.4em;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.sidebar nav a:hover {
  background: var(--color-primary-light);
}

.sidebar nav a.active {
  background: var(--color-primary);
  color: #fff;
  font-weight: bold;
}

.sidebar nav a.active .num {
  color: #fff;
}

/* Colorea el numerito de cada enlace según el bloque al que pertenece */
.nav-group--a li a .num { color: var(--color-group-a); }
.nav-group--b li a .num { color: var(--color-group-b); }
.nav-group--c li a .num { color: var(--color-group-c); }
.nav-group--d li a .num { color: var(--color-group-d); }

.nav-group--a li a.active { background: var(--color-group-a); }
.nav-group--b li a.active { background: var(--color-group-b); }
.nav-group--c li a.active { background: var(--color-group-c); }
.nav-group--d li a.active { background: var(--color-group-d); }

.nav-group--a li a.active .num,
.nav-group--b li a.active .num,
.nav-group--c li a.active .num,
.nav-group--d li a.active .num {
  color: #fff;
}

main.content {
  flex: 1;
  min-width: 0;
  padding: 2.5rem clamp(1.2rem, 4vw, 4rem) 6rem;
}

.content-inner {
  max-width: 780px;
  margin: 0 auto;
}

@media (max-width: 900px) {
  .topbar {
    display: flex;
  }
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    height: 100vh;
    padding-top: 4.5rem;
    transform: translateX(-105%);
    transition: transform 0.2s ease;
    z-index: 15;
    box-shadow: var(--shadow);
  }
  .sidebar.open {
    transform: translateX(0);
  }
  main.content {
    padding: 1.4rem 1.1rem 4rem;
  }
}

/* ---------- Encabezado de lección ---------- */

.lesson-kicker {
  display: inline-block;
  background: var(--color-accent-light);
  color: var(--color-accent);
  font-weight: bold;
  font-size: 0.8rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  padding: 0.25rem 0.7rem;
  border-radius: 999px;
  margin-bottom: 0.8rem;
}

.lesson-title {
  font-size: clamp(1.6rem, 4vw, 2.3rem);
  margin: 0 0 0.6rem;
}

.lesson-intro {
  font-size: 1.08rem;
  color: var(--color-text-soft);
  margin-bottom: 1.6rem;
}

.objectives {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.1rem 1.4rem;
  margin-bottom: 2rem;
}

.objectives h2 {
  margin-top: 0;
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--color-text-soft);
}

.objectives ul {
  margin: 0;
  padding-left: 1.2rem;
}

/* ---------- Bloques de contenido ---------- */

.section-block {
  margin: 2.4rem 0;
}

.section-block h2 {
  font-size: 1.4rem;
  border-bottom: 3px solid var(--color-primary-light);
  padding-bottom: 0.4rem;
}

.section-block h3 {
  font-size: 1.1rem;
  color: var(--color-primary-dark);
}

.tag {
  font-family: "SFMono-Regular", Consolas, Menlo, monospace;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  padding: 0.1rem 0.4rem;
  border-radius: 6px;
  font-size: 0.92em;
  white-space: nowrap;
}

.analogy {
  background: var(--color-accent-light);
  border-left: 5px solid var(--color-accent);
  border-radius: 0 10px 10px 0;
  padding: 1rem 1.2rem;
  margin: 1.2rem 0;
}

.analogy strong {
  color: var(--color-accent);
}

.callout {
  border-radius: var(--radius);
  padding: 1rem 1.3rem;
  margin: 1.2rem 0;
  border: 1px solid var(--color-border);
}

.callout-tip {
  background: var(--color-accent-light);
  border-color: var(--color-accent);
}

.callout-warning {
  background: var(--color-warning-bg);
  border-color: var(--color-warning-border);
}

.callout-exercise {
  background: var(--color-primary-light);
  border-color: var(--color-primary);
}

.callout p:first-child {
  margin-top: 0;
}
.callout p:last-child {
  margin-bottom: 0;
}

.callout-label {
  display: block;
  font-weight: bold;
  text-transform: uppercase;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  margin-bottom: 0.4rem;
}

.callout-tip .callout-label { color: var(--color-accent); }
.callout-warning .callout-label { color: #8a6d1d; }
.callout-exercise .callout-label { color: var(--color-primary-dark); }

/* ---------- Glosario (palabras nuevas explicadas) ---------- */

.glossary {
  background: var(--color-bg-alt);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius);
  padding: 1rem 1.3rem;
  margin: 1.2rem 0;
}

.glossary-label {
  display: block;
  font-weight: bold;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-soft);
  margin-bottom: 0.6rem;
}

.glossary dl {
  margin: 0;
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.5rem 1rem;
}

.glossary dt {
  font-weight: bold;
  color: var(--color-primary-dark);
  white-space: nowrap;
}

.glossary dd {
  margin: 0;
  color: var(--color-text);
}

@media (max-width: 560px) {
  .glossary dl {
    grid-template-columns: 1fr;
    gap: 0.15rem 0;
  }
  .glossary dd {
    margin-bottom: 0.5rem;
  }
}

/* ---------- Pasos numerados grandes (para procedimientos en el ordenador) ---------- */

.steps {
  list-style: none;
  counter-reset: step-counter;
  padding: 0;
  margin: 1.2rem 0;
}

.steps li {
  counter-increment: step-counter;
  position: relative;
  padding: 0.3rem 0 0.3rem 2.6rem;
  margin-bottom: 0.9rem;
}

.steps li::before {
  content: counter(step-counter);
  position: absolute;
  left: 0;
  top: 0.2rem;
  width: 1.9rem;
  height: 1.9rem;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  font-weight: bold;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
}

/* ---------- Bloques de código ---------- */

pre.code-block {
  background: var(--color-code-bg);
  color: var(--color-code-text);
  padding: 1rem 1.2rem;
  border-radius: 10px;
  overflow-x: auto;
  font-size: 0.88rem;
  margin: 1rem 0;
}

pre.code-block code {
  font-family: "SFMono-Regular", Consolas, Menlo, monospace;
  white-space: pre;
}

code:not(pre code) {
  font-family: "SFMono-Regular", Consolas, Menlo, monospace;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  padding: 0.1rem 0.35rem;
  border-radius: 6px;
  font-size: 0.9em;
}

.code-caption {
  font-size: 0.8rem;
  color: var(--color-text-soft);
  margin: -0.6rem 0 1rem;
}

/* ---------- Playground interactivo ---------- */

.playground {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 1.4rem 0;
  background: var(--color-bg-alt);
  box-shadow: var(--shadow);
}

.playground-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  background: var(--color-primary);
  color: #fff;
  padding: 0.6rem 1rem;
  font-size: 0.9rem;
  font-weight: bold;
}

.playground-header .dots {
  display: inline-flex;
  gap: 0.3rem;
}
.playground-header .dots span {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: rgba(255,255,255,0.55);
  display: inline-block;
}

.playground-body {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

@media (max-width: 720px) {
  .playground-body {
    grid-template-columns: 1fr;
  }
}

.playground-pane {
  min-width: 0;
}

.playground-pane + .playground-pane {
  border-left: 1px solid var(--color-border);
}

@media (max-width: 720px) {
  .playground-pane + .playground-pane {
    border-left: none;
    border-top: 1px solid var(--color-border);
  }
}

.playground-pane-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-soft);
  padding: 0.5rem 0.9rem 0;
  display: block;
}

.playground-input {
  width: 100%;
  min-height: 220px;
  border: none;
  resize: vertical;
  padding: 0.6rem 0.9rem 1rem;
  font-family: "SFMono-Regular", Consolas, Menlo, monospace;
  font-size: 0.86rem;
  background: var(--color-code-bg);
  color: var(--color-code-text);
  margin-top: 0.4rem;
  outline: none;
}

.playground-output {
  width: 100%;
  min-height: 220px;
  border: none;
  background: #fff;
  margin-top: 0.4rem;
}

.playground-footer {
  display: flex;
  gap: 0.6rem;
  padding: 0.7rem 0.9rem;
  border-top: 1px solid var(--color-border);
  flex-wrap: wrap;
}

/* ---------- Botones ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  border-radius: 999px;
  padding: 0.5rem 1.1rem;
  font-size: 0.88rem;
  font-weight: bold;
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text);
  cursor: pointer;
  text-decoration: none;
}

.btn-primary {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

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

.btn-ghost:hover {
  background: var(--color-primary-light);
}

/* ---------- Checklist ---------- */

.checklist {
  list-style: none;
  padding: 0;
  margin: 1rem 0;
}

.checklist li {
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
  padding: 0.4rem 0;
  border-bottom: 1px dashed var(--color-border);
}

.checklist li:last-child {
  border-bottom: none;
}

.checklist input[type="checkbox"] {
  margin-top: 0.3rem;
  width: 1.05rem;
  height: 1.05rem;
  accent-color: var(--color-primary);
}

/* ---------- Navegación entre lecciones (pie) ---------- */

.lesson-pager {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-border);
  flex-wrap: wrap;
}

.lesson-pager a {
  flex: 1;
  min-width: 200px;
  text-decoration: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.9rem 1.1rem;
  color: var(--color-text);
  background: var(--color-bg-alt);
}

.lesson-pager a:hover {
  border-color: var(--color-primary);
}

.lesson-pager .pager-dir {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--color-text-soft);
  margin-bottom: 0.2rem;
}

.lesson-pager .pager-next {
  text-align: right;
}

/* ---------- Portada (index.html) ---------- */

.hero {
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-accent-light));
  border-radius: 24px;
  padding: clamp(2rem, 5vw, 3.5rem);
  margin-bottom: 2.5rem;
}

.hero h1 {
  font-size: clamp(1.9rem, 5vw, 2.8rem);
  margin-top: 0;
}

.hero p {
  font-size: 1.1rem;
  color: var(--color-text-soft);
  max-width: 60ch;
}

.hero-actions {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
  margin-top: 1.3rem;
}

.module-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.1rem;
  margin: 1.5rem 0 2.5rem;
}

.module-card {
  display: block;
  text-decoration: none;
  color: var(--color-text);
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.2rem 1.3rem;
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.module-card:hover {
  transform: translateY(-3px);
  border-color: var(--color-primary);
}

.module-card .module-num {
  display: inline-block;
  background: var(--color-primary);
  color: #fff;
  font-weight: bold;
  font-size: 0.78rem;
  border-radius: 999px;
  padding: 0.15rem 0.65rem;
  margin-bottom: 0.6rem;
}

/* Variantes de color por bloque temático, para una portada más viva */
.module-card--a { border-top: 4px solid var(--color-group-a); }
.module-card--a .module-num { background: var(--color-group-a); }
.module-card--a:hover { border-color: var(--color-group-a); }

.module-card--b { border-top: 4px solid var(--color-group-b); }
.module-card--b .module-num { background: var(--color-group-b); }
.module-card--b:hover { border-color: var(--color-group-b); }

.module-card--c { border-top: 4px solid var(--color-group-c); }
.module-card--c .module-num { background: var(--color-group-c); }
.module-card--c:hover { border-color: var(--color-group-c); }

.module-card--d { border-top: 4px solid var(--color-group-d); }
.module-card--d .module-num { background: var(--color-group-d); }
.module-card--d:hover { border-color: var(--color-group-d); }

.module-card h3 {
  margin: 0 0 0.4rem;
  font-size: 1.08rem;
  color: var(--color-text);
}

.module-card p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--color-text-soft);
}

.activity-card {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-top: 4px solid var(--color-group-c);
  border-radius: var(--radius);
  padding: 1.4rem 1.6rem;
  margin-bottom: 1.4rem;
  box-shadow: var(--shadow);
}

.activity-card h3 {
  margin-top: 0;
}

/* ---------- Acordeón de bloques de módulos (portada) ---------- */

.details-group {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  margin: 1.2rem 0;
  overflow: hidden;
  background: var(--color-bg-alt);
}

.details-group summary {
  list-style: none;
  cursor: pointer;
  padding: 1rem 1.3rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.15rem;
  font-weight: bold;
}

.details-group summary::-webkit-details-marker {
  display: none;
}

.details-group summary::after {
  content: "▾";
  font-family: inherit;
  font-size: 1rem;
  transition: transform 0.15s ease;
  color: var(--color-text-soft);
  flex-shrink: 0;
}

.details-group[open] summary::after {
  transform: rotate(180deg);
}

.details-group summary .summary-count {
  font-family: "Trebuchet MS", "Segoe UI", Verdana, sans-serif;
  font-weight: normal;
  font-size: 0.82rem;
  color: var(--color-text-soft);
  margin-right: auto;
  margin-left: 0.6rem;
}

.details-group .details-body {
  padding: 0 1.3rem 1.3rem;
}

.details-group--a { border-top: 4px solid var(--color-group-a); }
.details-group--a summary { color: var(--color-group-a); }
.details-group--b { border-top: 4px solid var(--color-group-b); }
.details-group--b summary { color: var(--color-group-b); }

/* ---------- Barra de progreso (portada) ---------- */

.progress-widget {
  background: rgba(255, 255, 255, 0.6);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.9rem 1.2rem;
  margin-top: 1.4rem;
  max-width: 420px;
}

:root[data-theme="dark"] .progress-widget {
  background: rgba(0, 0, 0, 0.15);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .progress-widget {
    background: rgba(0, 0, 0, 0.15);
  }
}

.progress-widget-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  font-weight: bold;
  margin-bottom: 0.5rem;
}

.progress-track {
  height: 10px;
  border-radius: 999px;
  background: var(--color-border);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-group-c));
  transition: width 0.4s ease;
}

.pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0.8rem 0;
}

.pill {
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  border-radius: 999px;
  padding: 0.25rem 0.7rem;
  font-size: 0.8rem;
  font-weight: bold;
}

footer.site-footer {
  text-align: center;
  color: var(--color-text-soft);
  font-size: 0.85rem;
  padding: 2rem 1rem;
}

table.ref-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.92rem;
}

table.ref-table th,
table.ref-table td {
  border: 1px solid var(--color-border);
  padding: 0.5rem 0.7rem;
  text-align: left;
  vertical-align: top;
}

table.ref-table th {
  background: var(--color-bg-alt);
}

.font-demo-system {
  font-family: Georgia, "Times New Roman", serif;
}

.font-demo-google {
  font-family: "Patrick Hand", cursive;
}