/* ============================================
   SEPUEDOHACERESTO.ES - CSS Optimizado SEO
   Peso: ~6KB | Sin dependencias externas | Modo oscuro incluido
   ============================================ */

/* VARIABLES CSS - Modo claro (por defecto) */
:root {
  --color-bg: #f6f7f8;
  --color-bg-card: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-bg-answer: #f0fdf4;
  --color-text: #1f2933;
  --color-text-secondary: #475569;
  --color-text-tertiary: #64748b;
  --color-text-muted: #94a3b8;
  --color-heading: #0f172a;
  --color-border: #e2e8f0;
  --color-border-light: #e4e7eb;
  --color-primary: #3b82f6;
  --color-primary-hover: #2563eb;
  --color-success: #10b981;
  --color-success-bg: #f0fdf4;
  --color-success-border: #86efac;
  --color-success-text: #065f46;
  --color-ad-bg: #f1f5f9;
  --color-ad-border: #cbd5e1;
  --color-ad-text: #94a3b8;
  --color-shadow: rgba(0,0,0,.08);
  --color-shadow-hover: rgba(59,130,246,.15);
}

/* MODO OSCURO - Variables */
[data-theme="dark"] {
  --color-bg: #0f172a;
  --color-bg-card: #1e293b;
  --color-bg-alt: #334155;
  --color-bg-answer: #065f46;
  --color-text: #e2e8f0;
  --color-text-secondary: #cbd5e1;
  --color-text-tertiary: #94a3b8;
  --color-text-muted: #64748b;
  --color-heading: #f1f5f9;
  --color-border: #334155;
  --color-border-light: #475569;
  --color-primary: #60a5fa;
  --color-primary-hover: #3b82f6;
  --color-success: #34d399;
  --color-success-bg: #064e3b;
  --color-success-border: #065f46;
  --color-success-text: #d1fae5;
  --color-ad-bg: #1e293b;
  --color-ad-border: #334155;
  --color-ad-text: #64748b;
  --color-shadow: rgba(0,0,0,.3);
  --color-shadow-hover: rgba(96,165,250,.2);
}

/* Auto modo oscuro según preferencia del sistema */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-bg: #0f172a;
    --color-bg-card: #1e293b;
    --color-bg-alt: #334155;
    --color-bg-answer: #065f46;
    --color-text: #e2e8f0;
    --color-text-secondary: #cbd5e1;
    --color-text-tertiary: #94a3b8;
    --color-text-muted: #64748b;
    --color-heading: #f1f5f9;
    --color-border: #334155;
    --color-border-light: #475569;
    --color-primary: #60a5fa;
    --color-primary-hover: #3b82f6;
    --color-success: #34d399;
    --color-success-bg: #064e3b;
    --color-success-border: #065f46;
    --color-success-text: #d1fae5;
    --color-ad-bg: #1e293b;
    --color-ad-border: #334155;
    --color-ad-text: #64748b;
    --color-shadow: rgba(0,0,0,.3);
    --color-shadow-hover: rgba(96,165,250,.2);
  }
}

/* RESET Y BASE */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  font-size: 16px;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* CONTENEDOR PRINCIPAL */
.container {
  max-width: 760px;
  margin: 0 auto;
  padding: 20px;
}

/* HEADER */
.header {
  background: var(--color-bg-card);
  border-bottom: 1px solid var(--color-border-light);
  padding: 32px 0;
  margin-bottom: 32px;
  position: relative;
}

.header-simple {
  padding: 16px 0;
  margin-bottom: 24px;
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-heading);
  margin-bottom: 8px;
}

.tagline {
  font-size: 1rem;
  color: var(--color-text-tertiary);
  font-weight: 400;
}

.back-link {
  color: var(--color-primary);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s;
}

.back-link:hover {
  color: var(--color-primary-hover);
  text-decoration: underline;
}

/* BOTÓN MODO OSCURO */
.theme-toggle {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: 50%;
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  font-size: 1.2rem;
  flex-shrink: 0;
  margin-left: 16px;
}

.theme-toggle:hover {
  background: var(--color-primary);
  border-color: var(--color-primary);
  transform: rotate(180deg);
}

.theme-toggle:active {
  transform: rotate(180deg) scale(0.95);
}

.header-content {
  flex: 1;
}

/* CARDS */
.card {
  background: var(--color-bg-card);
  border-radius: 12px;
  padding: 28px;
  box-shadow: 0 1px 3px var(--color-shadow);
  margin-bottom: 24px;
  transition: background-color 0.3s ease;
}

.intro-card {
  border-left: 4px solid var(--color-primary);
}

.answer-card {
  border-left: 4px solid var(--color-success);
}

/* RESPUESTA DIRECTA */
.direct-answer {
  background: var(--color-success-bg);
  border: 1px solid var(--color-success-border);
  border-radius: 8px;
  padding: 20px;
  margin: 20px 0;
}

.direct-answer p {
  font-size: 1.1rem;
  line-height: 1.7;
  color: var(--color-success-text);
}

/* TIPOGRAFÍA */
h1 {
  font-size: 1.85rem;
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-heading);
  margin-bottom: 16px;
}

h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-top: 32px;
  margin-bottom: 16px;
  color: var(--color-heading);
}

h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--color-text);
}

.section-title {
  margin-top: 48px;
  margin-bottom: 24px;
  font-size: 1.6rem;
}

p {
  margin-bottom: 16px;
  color: var(--color-text-secondary);
}

strong {
  font-weight: 600;
  color: var(--color-text);
}

ul {
  margin-left: 24px;
  margin-bottom: 16px;
}

li {
  margin-bottom: 8px;
  color: var(--color-text-secondary);
}

/* CATEGORÍAS */
.categories {
  margin-top: 48px;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.category-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 24px 20px;
  text-align: center;
  transition: all 0.3s ease;
  cursor: pointer;
}

.category-card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 4px 12px var(--color-shadow-hover);
  transform: translateY(-2px);
}

.category-icon {
  font-size: 2.5rem;
  margin-bottom: 12px;
}

.category-card h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
  color: var(--color-heading);
}

.category-card p {
  font-size: 0.9rem;
  color: var(--color-text-tertiary);
  margin-bottom: 0;
}

/* LISTA DE PREGUNTAS */
.questions-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 20px;
}

.question-item {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  text-decoration: none;
  color: var(--color-text);
  transition: all 0.2s ease;
}

.question-item:hover {
  border-color: var(--color-primary);
  background: var(--color-bg-alt);
  transform: translateX(4px);
}

.question-text {
  font-size: 1rem;
  font-weight: 500;
}

.question-arrow {
  color: var(--color-primary);
  font-size: 1.2rem;
  font-weight: 700;
}

/* SECCIONES DE CONTENIDO */
.content-section {
  margin-top: 32px;
  margin-bottom: 32px;
}

/* FACTORES */
.factors-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-top: 20px;
}

.factor-item {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 16px;
}

.factor-item h3 {
  font-size: 1rem;
  margin-bottom: 8px;
  color: var(--color-heading);
}

.factor-item p {
  font-size: 0.9rem;
  color: var(--color-text-tertiary);
  margin-bottom: 0;
}

/* FAQ */
.faq-section {
  background: var(--color-bg-card);
  border-radius: 12px;
  padding: 28px;
  box-shadow: 0 1px 3px var(--color-shadow);
  margin-top: 40px;
}

.faq-item {
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-item h3 {
  font-size: 1.05rem;
  color: var(--color-heading);
  margin-bottom: 8px;
}

.faq-item p {
  font-size: 0.95rem;
  color: var(--color-text-tertiary);
  margin-bottom: 0;
}

/* PREGUNTAS RELACIONADAS */
.related-questions {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 2px solid #e2e8f0;
}

/* ESPACIOS ADSENSE */
.ad-space {
  background: var(--color-ad-bg);
  border: 1px dashed var(--color-ad-border);
  border-radius: 8px;
  padding: 80px 20px;
  text-align: center;
  margin: 32px 0;
  min-height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ad-space-center {
  margin: 48px 0;
}

.ad-label {
  color: var(--color-ad-text);
  font-size: 0.85rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* FOOTER */
.footer {
  background: var(--color-bg-card);
  border-top: 1px solid var(--color-border-light);
  margin-top: 64px;
  padding: 32px 0;
  text-align: center;
}

.footer p {
  font-size: 0.9rem;
  color: var(--color-text-tertiary);
  margin-bottom: 8px;
}

.footer-copyright {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.footer a {
  color: var(--color-primary);
  text-decoration: none;
}

.footer a:hover {
  text-decoration: underline;
}

/* RESPONSIVE */
@media (max-width: 640px) {
  .container {
    padding: 16px;
  }

  h1 {
    font-size: 1.5rem;
  }

  h2 {
    font-size: 1.25rem;
  }

  .header {
    padding: 24px 0;
  }
  
  .header .container {
    flex-wrap: wrap;
    gap: 16px;
  }
  
  .header-content {
    flex: 1;
    min-width: 200px;
  }

  .logo {
    font-size: 1.4rem;
    margin-bottom: 4px;
  }
  
  .tagline {
    font-size: 0.9rem;
  }
  
  .theme-toggle {
    width: 38px;
    height: 38px;
    font-size: 1rem;
  }

  .card {
    padding: 20px;
  }

  .category-grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .factors-list {
    grid-template-columns: 1fr;
  }

  .direct-answer p {
    font-size: 1rem;
  }

  .ad-space {
    padding: 60px 16px;
  }
}

/* NUEVAS SECCIONES DE CONTENIDO */
.detailed-info h2,
.practical-cases h2 {
  color: var(--primary-color);
  margin-bottom: 16px;
}

.detailed-content,
.cases-content {
  line-height: 1.8;
  font-size: 1rem;
}

.detailed-content p,
.cases-content p {
  margin-bottom: 16px;
}

.detailed-content strong,
.cases-content strong {
  color: var(--text-primary);
  font-weight: 600;
}

.detailed-content ul,
.detailed-content ol,
.cases-content ul,
.cases-content ol {
  margin: 16px 0;
  padding-left: 24px;
}

.detailed-content li,
.cases-content li {
  margin-bottom: 12px;
  line-height: 1.7;
}

/* Referencias y enlaces externos */
.references {
  margin-top: 32px;
  padding: 24px;
  background: var(--bg-color);
  border-radius: 8px;
  border-left: 4px solid var(--primary-color);
}

.references h3 {
  color: var(--primary-color);
  margin-bottom: 16px;
  font-size: 1.1rem;
}

.references-content {
  line-height: 1.8;
}

.references-content a {
  color: var(--primary-color);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: all 0.2s ease;
  font-weight: 500;
}

.references-content a:hover {
  border-bottom-color: var(--primary-color);
}

.references-content p {
  margin-bottom: 12px;
}

.references-content ul {
  list-style: none;
  padding-left: 0;
}

.references-content li {
  padding: 8px 0;
  padding-left: 24px;
  position: relative;
}

.references-content li::before {
  content: "🔗";
  position: absolute;
  left: 0;
}

/* ARTICLE META (fecha actualización) */
.article-meta {
  margin-top: 48px;
  padding: 20px;
  background: var(--bg-color);
  border-left: 4px solid var(--primary-color);
  border-radius: 8px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.article-meta p {
  margin: 8px 0;
  line-height: 1.6;
}

.article-meta time {
  color: var(--text-primary);
}

/* BREADCRUMBS */
.breadcrumbs {
  margin: 0 0 32px 0;
  padding: 12px 20px;
  background: var(--card-bg);
  border-radius: 8px;
  border: 1px solid var(--border-color);
  font-size: 0.875rem;
}

.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  list-style: none;
  padding: 0;
  margin: 0;
  color: var(--text-secondary);
}

.breadcrumbs li {
  display: flex;
  align-items: center;
}

.breadcrumbs li:not(:last-child)::after {
  content: "›";
  margin-left: 8px;
  color: var(--text-tertiary);
  font-size: 1.1rem;
  opacity: 0.5;
}

.breadcrumbs a {
  color: var(--primary-color);
  text-decoration: none;
  transition: all 0.2s ease;
  padding: 4px 8px;
  border-radius: 4px;
}

.breadcrumbs a:hover {
  background: var(--bg-color);
  color: var(--primary-hover);
}

.breadcrumbs li:last-child {
  color: var(--text-primary);
  font-weight: 500;
  padding: 4px 8px;
  background: var(--bg-color);
  border-radius: 4px;
}

/* OPTIMIZACIONES PERFORMANCE */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* PRINT */
@media print {
  .ad-space,
  .related-questions,
  .back-link,
  .footer {
    display: none;
  }
}