/* =========================================================
   SysLab — style.css
   Sistema de diseño único para todo el sitio.
   No añadas estilos "inline" en las páginas: todo vive aquí
   para poder cambiar el aspecto global desde un solo archivo.
   ========================================================= */

/* ---------- 1. TOKENS ---------- */
:root {
  /* Paleta — inspirada en paneles de red y manuales técnicos */
  --color-bg:        #F6F7F5;
  --color-bg-panel:  #FFFFFF;
  --color-bg-sunken: #EFF1EE;
  --color-border:    #DDE1DC;
  --color-border-strong: #C3C9C1;

  --color-ink:       #12181A;
  --color-ink-soft:  #4B5560;
  --color-ink-faint: #77828B;

  --color-accent:        #0F7B6C; /* teal señal — enlaces, CTAs, éxito */
  --color-accent-dark:   #0B5C51;
  --color-accent-bg:     #E4F1EE;

  --color-warn:      #9A5B12; /* ámbar — advertencias */
  --color-warn-bg:   #FBF0DE;

  --color-danger:    #A32B1F; /* rojo apagado — errores */
  --color-danger-bg: #FBEAE7;

  --color-linux:    #0F7B6C;
  --color-redes:    #1D5FA8;
  --color-ciber:    #A32B1F;
  --color-servidores: #7A4FBF;

  --font-sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "IBM Plex Mono", Menlo, Consolas, "Liberation Mono", monospace;

  --radius-sm: 4px;
  --radius-md: 8px;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4.5rem;

  --container: 1180px;
  --shadow-sm: 0 1px 2px rgba(18,24,26,0.06);
  --shadow-md: 0 6px 20px rgba(18,24,26,0.08);

  color-scheme: light;
}

[data-theme="dark"] {
  color-scheme: dark;
  --color-bg:        #0E1416;
  --color-bg-panel:  #151D20;
  --color-bg-sunken: #0B1012;
  --color-border:    #263034;
  --color-border-strong: #354044;

  --color-ink:       #E9EEEE;
  --color-ink-soft:  #AEBABE;
  --color-ink-faint: #79868B;

  --color-accent:      #35C4A8;
  --color-accent-dark: #7FE0CB;
  --color-accent-bg:   #12302B;

  --color-warn:     #E3A748;
  --color-warn-bg:  #322616;

  --color-danger:     #E6685A;
  --color-danger-bg:  #341A17;

  --color-linux: #35C4A8;
  --color-redes: #5B9BE0;
  --color-ciber: #E6685A;
  --color-servidores: #B79CF0;
}

/* ---------- 2. RESET ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-ink);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}
img, svg { max-width: 100%; display: block; }
a { color: var(--color-accent); text-decoration-thickness: 1.5px; text-underline-offset: 2px; }
a:hover { color: var(--color-accent-dark); }
ul, ol { padding-left: 1.25em; }
h1, h2, h3, h4 { line-height: 1.25; letter-spacing: -0.01em; font-weight: 700; margin: 0 0 var(--space-3); }
h1 { font-size: clamp(1.9rem, 1.5rem + 1.8vw, 2.75rem); }
h2 { font-size: clamp(1.4rem, 1.2rem + 1vw, 1.9rem); margin-top: var(--space-7); }
h3 { font-size: 1.2rem; margin-top: var(--space-5); }
p { margin: 0 0 var(--space-4); color: var(--color-ink-soft); }
code, pre, kbd { font-family: var(--font-mono); }
code { background: var(--color-bg-sunken); border: 1px solid var(--color-border); padding: 0.1em 0.4em; border-radius: var(--radius-sm); font-size: 0.9em; color: var(--color-ink); }
:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 2px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; }
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
}

.container { max-width: var(--container); margin: 0 auto; padding: 0 var(--space-5); }
main { display: block; }
.section { padding: var(--space-7) 0; }
.section--tight { padding: var(--space-6) 0; }
.section-head { max-width: 640px; margin-bottom: var(--space-6); }
.section-head p { margin-bottom: 0; }
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent-dark);
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
}
.eyebrow::before { content: "//"; color: var(--color-ink-faint); }

/* ---------- 3. HEADER / NAV ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-5);
  max-width: var(--container);
  margin: 0 auto;
  gap: var(--space-4);
}
.nav-brand {
  display: flex;
  align-items: baseline;
  gap: 0.4rem;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--color-ink);
  text-decoration: none;
}
.nav-brand .dot { color: var(--color-accent); }
.nav-brand:hover { color: var(--color-ink); }

.nav-list {
  list-style: none;
  display: flex;
  align-items: center;
  gap: var(--space-5);
  margin: 0;
  padding: 0;
}
.nav-list a {
  color: var(--color-ink-soft);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 600;
  padding: var(--space-2) 0;
  border-bottom: 2px solid transparent;
  transition: color 0.12s ease, border-color 0.12s ease;
}
.nav-list a:hover, .nav-list a[aria-current="page"] {
  color: var(--color-ink);
  border-bottom-color: var(--color-accent);
}

.nav-tools { display: flex; align-items: center; gap: var(--space-3); }

.btn-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px; height: 40px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: var(--color-bg-panel);
  color: var(--color-ink-soft);
  cursor: pointer;
}
.btn-icon:hover { color: var(--color-ink); border-color: var(--color-border-strong); }

.nav-toggle { display: none; }

/* Menú móvil */
@media (max-width: 860px) {
  .nav-toggle {
    display: inline-flex;
  }
  .nav-list {
    position: fixed;
    inset: 64px 0 auto 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--color-bg-panel);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-4) var(--space-5) var(--space-6);
    gap: 0;
    transform: translateY(-8px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.15s ease, transform 0.15s ease;
    max-height: calc(100vh - 64px);
    overflow-y: auto;
  }
  .nav-list.is-open { opacity: 1; transform: translateY(0); pointer-events: auto; }
  .nav-list li { border-bottom: 1px solid var(--color-border); }
  .nav-list a { display: block; padding: var(--space-4) 0; border-bottom: none; }
}

/* ---------- 4. BUSCADOR ---------- */
.search-box { position: relative; }
.search-input {
  width: 100%;
  font: inherit;
  padding: var(--space-4) var(--space-5);
  padding-right: 3rem;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  background: var(--color-bg-panel);
  color: var(--color-ink);
}
.search-input::placeholder { color: var(--color-ink-faint); }
.search-hero .search-input { font-size: 1.05rem; padding: var(--space-5); }
.search-submit {
  position: absolute;
  right: var(--space-2);
  top: 50%;
  transform: translateY(-50%);
  border: none;
  background: var(--color-accent);
  color: #fff;
  width: 40px; height: 40px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
}
.search-submit:hover { background: var(--color-accent-dark); }

.search-results {
  margin-top: var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-panel);
  overflow: hidden;
  display: none;
}
.search-results.is-visible { display: block; }
.search-results ul { list-style: none; margin: 0; padding: 0; }
.search-results li { border-bottom: 1px solid var(--color-border); }
.search-results li:last-child { border-bottom: none; }
.search-results a { display: block; padding: var(--space-4) var(--space-5); text-decoration: none; }
.search-results a:hover { background: var(--color-bg-sunken); }
.result-title { color: var(--color-ink); font-weight: 700; margin-bottom: 2px; }
.result-desc { color: var(--color-ink-soft); font-size: 0.9rem; margin: 0; }
.result-tag { font-family: var(--font-mono); font-size: 0.72rem; color: var(--color-accent-dark); text-transform: uppercase; letter-spacing: 0.05em; }
.search-empty, .search-hint { padding: var(--space-4) var(--space-5); color: var(--color-ink-faint); font-size: 0.9rem; }
.search-page-input { margin-bottom: var(--space-6); }

/* ---------- 5. HERO ---------- */
.hero {
  padding: var(--space-8) 0 var(--space-7);
  border-bottom: 1px solid var(--color-border);
}
.hero-prompt {
  font-family: var(--font-mono);
  color: var(--color-accent);
  font-size: 0.95rem;
  margin-bottom: var(--space-4);
  word-break: break-word;
}
.hero-prompt .cursor {
  display: inline-block;
  width: 0.55em;
  background: var(--color-accent);
  margin-left: 2px;
  animation: blink 1.1s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }
.hero h1 { max-width: 18ch; }
.hero-sub { max-width: 56ch; font-size: 1.08rem; }
.hero .search-box { max-width: 640px; margin-top: var(--space-6); }

@media (max-width: 480px) {
  .hero-prompt { font-size: 0.82rem; }
}

/* ---------- 6. TARJETAS DE TEMAS ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: var(--space-4);
}
.topic-card {
  display: block;
  text-decoration: none;
  background: var(--color-bg-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  transition: border-color 0.12s ease, transform 0.12s ease;
  border-top: 3px solid var(--topic-color, var(--color-accent));
}
.topic-card:hover { border-color: var(--color-border-strong); transform: translateY(-2px); }
.topic-card .topic-icon { font-size: 1.6rem; margin-bottom: var(--space-3); }
.topic-card h3 { margin: 0 0 var(--space-2); color: var(--color-ink); }
.topic-card p { margin: 0; font-size: 0.92rem; }
.topic-card--linux { --topic-color: var(--color-linux); }
.topic-card--redes { --topic-color: var(--color-redes); }
.topic-card--ciberseguridad { --topic-color: var(--color-ciber); }
.topic-card--servidores { --topic-color: var(--color-servidores); }

/* ---------- 7. RUTAS DE APRENDIZAJE ---------- */
.path-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-5);
}
.path-card {
  background: var(--color-bg-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  display: flex;
  flex-direction: column;
  transition: border-color 0.12s ease, box-shadow 0.12s ease;
}
.path-card:hover { border-color: var(--color-border-strong); box-shadow: var(--shadow-sm); }
.path-card h3 { margin-top: 0; }
.path-card .path-meta { font-family: var(--font-mono); font-size: 0.78rem; color: var(--color-ink-faint); margin-bottom: var(--space-3); }
.path-progress {
  height: 6px;
  border-radius: 999px;
  background: var(--color-bg-sunken);
  overflow: hidden;
  margin: var(--space-3) 0 var(--space-4);
}
.path-progress > span { display: block; height: 100%; background: var(--color-accent); width: 0%; }
.path-steps { list-style: none; margin: 0 0 var(--space-4); padding: 0; font-size: 0.9rem; }
.path-steps li {
  display: flex; align-items: center; gap: var(--space-3);
  padding: var(--space-2) 0;
  border-bottom: 1px dashed var(--color-border);
  color: var(--color-ink-soft);
}
.path-steps li:last-child { border-bottom: none; }
.path-steps .step-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-ink-faint);
  width: 1.6em;
}
.path-steps li[data-active="true"] { color: var(--color-ink); font-weight: 600; }
.path-steps a { text-decoration: none; color: inherit; }
.path-steps a:hover { color: var(--color-accent); }
.path-card .btn { margin-top: auto; }

/* ---------- 8. BOTONES ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font: inherit;
  font-weight: 600;
  font-size: 0.92rem;
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background-color 0.12s ease, border-color 0.12s ease, transform 0.08s ease;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--color-accent); color: #fff; }
.btn-primary:hover { background: var(--color-accent-dark); color: #fff; }
.btn-outline { background: transparent; border-color: var(--color-border-strong); color: var(--color-ink); }
.btn-outline:hover { border-color: var(--color-ink); }
.btn-sm { padding: var(--space-2) var(--space-3); font-size: 0.82rem; }

/* ---------- 9. LISTAS / ÍNDICES (guías, problemas, herramientas) ---------- */
.item-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-4);
}
.item-card {
  background: var(--color-bg-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-4) var(--space-5);
  text-decoration: none;
  display: block;
  transition: border-color 0.12s ease, transform 0.12s ease, box-shadow 0.12s ease;
}
.item-card:hover { border-color: var(--color-border-strong); transform: translateY(-2px); box-shadow: var(--shadow-sm); }
.item-card h3, .item-card h4 { margin: var(--space-1) 0 var(--space-2); color: var(--color-ink); font-size: 1.02rem; }
.item-card p { margin: 0; font-size: 0.88rem; }

.status-dot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; background: var(--dot-color, var(--color-accent)); margin-right: 6px; }
.tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-ink-faint);
}

.category-block { margin-bottom: var(--space-7); }
.category-block h2 { display: flex; align-items: center; margin-top: var(--space-6); }

/* ---------- 10. LISTA DE PROBLEMAS (inicio) ---------- */
.problem-cols {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-6);
}
.problem-cols h3 { margin-top: 0; }
.problem-cols ul { list-style: none; margin: 0; padding: 0; }
.problem-cols li { border-bottom: 1px solid var(--color-border); }
.problem-cols li:last-child { border-bottom: none; }
.problem-cols a {
  display: flex; align-items: center;
  padding: var(--space-3) 0;
  text-decoration: none;
  color: var(--color-ink-soft);
  font-size: 0.95rem;
}
.problem-cols a:hover { color: var(--color-accent); }
.problem-cols a::before { content: "›"; margin-right: var(--space-2); color: var(--color-ink-faint); font-weight: 700; }

/* ---------- 11. HERRAMIENTAS: tarjetas + UI funcional ---------- */
.tool-panel {
  background: var(--color-bg-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  margin: var(--space-6) 0;
}
.tool-form { display: grid; gap: var(--space-4); max-width: 480px; }
.field { display: grid; gap: var(--space-2); }
.field label { font-weight: 600; font-size: 0.9rem; }
.field .hint { font-size: 0.8rem; color: var(--color-ink-faint); }
input[type="text"], input[type="number"], select {
  font: inherit;
  padding: var(--space-3);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-ink);
  width: 100%;
}
.field-error { color: var(--color-danger); font-size: 0.85rem; display: none; }
.field.has-error input { border-color: var(--color-danger); }
.field.has-error .field-error { display: block; }

.tool-result {
  margin-top: var(--space-6);
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-5);
  display: none;
  overflow-x: auto;
}
.tool-result.is-visible { display: block; }
.result-table { width: 100%; min-width: 380px; border-collapse: collapse; font-family: var(--font-mono); font-size: 0.92rem; }
.result-table th, .result-table td { text-align: left; padding: var(--space-3); border-bottom: 1px solid var(--color-border); }
.result-table th { color: var(--color-ink-faint); font-weight: 600; width: 45%; }

/* ---------- 12. ARTÍCULO (guías / problemas) ---------- */
.breadcrumbs {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--color-ink-faint);
  margin: var(--space-5) 0;
}
.breadcrumbs a { color: var(--color-ink-faint); text-decoration: none; }
.breadcrumbs a:hover { color: var(--color-accent); }
.breadcrumbs .sep { margin: 0 var(--space-2); }

.article-head { max-width: 760px; }
.article-meta {
  display: flex; flex-wrap: wrap; gap: var(--space-4);
  font-size: 0.85rem; color: var(--color-ink-faint);
  margin: var(--space-3) 0 var(--space-5);
  font-family: var(--font-mono);
}
.article-lede { font-size: 1.1rem; color: var(--color-ink-soft); }

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: var(--space-7);
  align-items: start;
}
@media (max-width: 960px) {
  .article-layout { grid-template-columns: 1fr; }
}
.article-body { max-width: 760px; }
.article-body > *:first-child { margin-top: 0; }
.article-body ul, .article-body ol { color: var(--color-ink-soft); }
.article-body li { margin-bottom: var(--space-2); }

.toc {
  position: sticky;
  top: 88px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  background: var(--color-bg-panel);
}
.toc h2 { margin: 0 0 var(--space-3); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--color-ink-faint); }
.toc ol { list-style: none; margin: 0; padding: 0; font-size: 0.9rem; }
.toc li { margin-bottom: var(--space-2); }
.toc a { color: var(--color-ink-soft); text-decoration: none; }
.toc a:hover { color: var(--color-accent); }

.code-block {
  position: relative;
  background: #14181C;
  color: #E9EEEE;
  border-radius: var(--radius-md);
  margin: var(--space-5) 0;
  overflow: hidden;
  border: 1px solid #262E33;
  box-shadow: var(--shadow-md);
}
[data-theme="dark"] .code-block { background: #05080A; border-color: #1B2226; }

/* Terminal variant: estilo inspirado en terminales Linux (bash) */
.code-block.terminal {
  background: linear-gradient(180deg, #071018 0%, #041014 100%);
  color: #c8f5c8;
  border-color: #052126;
}
.code-block.terminal .code-block-bar { background: rgba(255,255,255,0.02); border-bottom-color: rgba(255,255,255,0.03); }
.code-block.terminal .code-block-label { color: rgba(200,245,200,0.85); }
.code-block.terminal pre { color: #dff6d8; }
.code-block.terminal .prompt-symbol { color: #7ee08a; }


/* Barra de ventana de terminal */
.code-block-bar {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3) var(--space-2) var(--space-4);
  background: rgba(255,255,255,0.035);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.code-block-dots { display: inline-flex; gap: 7px; flex-shrink: 0; }
.code-block-dot { width: 11px; height: 11px; border-radius: 50%; display: inline-block; }
.code-block-dot:nth-child(1) { background: var(--color-danger); opacity: 0.75; }
.code-block-dot:nth-child(2) { background: var(--color-warn); opacity: 0.75; }
.code-block-dot:nth-child(3) { background: var(--color-accent); opacity: 0.75; }
.code-block-label {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: rgba(233,238,238,0.45);
  letter-spacing: 0.03em;
  flex: 1;
  text-align: center;
  user-select: none;
}

.code-block pre { margin: 0; padding: var(--space-5); overflow-x: auto; font-size: 0.88rem; line-height: 1.65; scrollbar-width: thin; scrollbar-color: rgba(255,255,255,0.25) transparent; }
.code-block pre::-webkit-scrollbar { height: 8px; }
.code-block pre::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.2); border-radius: 999px; }
.code-block pre::-webkit-scrollbar-thumb:hover { background: rgba(255,255,255,0.35); }

/* Prompt ($ o #) resaltado al inicio de línea, y líneas de comentario atenuadas */
.prompt-symbol { color: var(--color-accent); font-weight: 700; user-select: none; }
.code-comment { color: rgba(233,238,238,0.4); font-style: italic; }

.copy-btn {
  font-family: var(--font-sans);
  font-size: 0.76rem;
  font-weight: 600;
  background: rgba(255,255,255,0.06);
  color: rgba(233,238,238,0.85);
  border: 1px solid rgba(255,255,255,0.16);
  border-radius: var(--radius-sm);
  padding: 5px 10px;
  cursor: pointer;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}
.copy-btn:hover { background: rgba(255,255,255,0.14); color: #fff; }
.copy-btn[data-copied="true"] { color: var(--color-accent); border-color: var(--color-accent); background: var(--color-accent-bg); }

.callout {
  border-left: 3px solid var(--color-accent);
  background: var(--color-accent-bg);
  padding: var(--space-4) var(--space-5);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: var(--space-5) 0;
}
.callout p:last-child { margin-bottom: 0; }
.callout-title { font-weight: 700; margin-bottom: var(--space-1); color: var(--color-ink); }
.callout--warn { border-color: var(--color-warn); background: var(--color-warn-bg); }
.callout--danger { border-color: var(--color-danger); background: var(--color-danger-bg); }

.faq-item { border-bottom: 1px solid var(--color-border); padding: var(--space-4) 0; }
.faq-item summary { cursor: pointer; font-weight: 700; color: var(--color-ink); list-style: none; display: flex; justify-content: space-between; gap: var(--space-3); }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; color: var(--color-accent); font-size: 1.2rem; }
.faq-item[open] summary::after { content: "–"; }
.faq-item p { margin-top: var(--space-3); }

.related-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: var(--space-4); margin-top: var(--space-4); }

/* Flujo problema → causas → comprobar → soluciones → prevención */
.problem-flow { list-style: none; margin: var(--space-5) 0; padding: 0; display: grid; gap: var(--space-3); }
.problem-flow li {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-ink-faint);
  display: flex; align-items: center; gap: var(--space-3);
}
.problem-flow li.is-current { color: var(--color-accent-dark); border-color: var(--color-accent); font-weight: 700; }

/* ---------- 13. AD SLOT (placeholder, sin código real de AdSense) ---------- */
.ad-slot {
  border: 1px dashed var(--color-border-strong);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  text-align: center;
  color: var(--color-ink-faint);
  font-size: 0.8rem;
  font-family: var(--font-mono);
  margin: var(--space-6) 0;
  background: var(--color-bg-sunken);
}

/* ---------- 14. FORMULARIOS (contacto) ---------- */
.form-grid { display: grid; gap: var(--space-4); max-width: 560px; }
textarea {
  font: inherit;
  padding: var(--space-3);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-ink);
  min-height: 140px;
  resize: vertical;
}

/* ---------- 15. FOOTER ---------- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-7) 0 var(--space-6);
  margin-top: var(--space-8);
  background: var(--color-bg-sunken);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: var(--space-6);
}
@media (max-width: 760px) { .footer-grid { grid-template-columns: repeat(2, 1fr); } }
.footer-grid h4 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--color-ink-faint); margin-bottom: var(--space-3); }
.footer-grid ul { list-style: none; margin: 0; padding: 0; }
.footer-grid li { margin-bottom: var(--space-2); }
.footer-grid a { color: var(--color-ink-soft); text-decoration: none; font-size: 0.9rem; }
.footer-grid a:hover { color: var(--color-accent); }
.footer-brand { font-family: var(--font-mono); font-weight: 700; color: var(--color-ink); margin-bottom: var(--space-2); }
.footer-bottom {
  margin-top: var(--space-6);
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-border);
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: var(--space-3);
  font-size: 0.82rem; color: var(--color-ink-faint);
}

/* ---------- 16. UTILIDADES ---------- */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.stack { display: grid; gap: var(--space-4); }
.hidden { display: none !important; }

/* Skip link (mejora accesibilidad: salta al contenido principal) */
.skip-link {
  position: absolute;
  left: 0;
  top: -48px;
  background: var(--color-accent);
  color: #ffffff;
  padding: 0.6rem 0.9rem;
  z-index: 60;
  border-bottom-right-radius: 6px;
  border-bottom-left-radius: 6px;
  text-decoration: none;
  font-weight: 700;
}
.skip-link:focus {
  top: 12px;
  outline: 2px solid #fff;
  outline-offset: 2px;
}