/* ==========================================================================
   papel.bond — Estilos principales
   Mobile-first. Sin frameworks. Optimizado para Lighthouse.
   Paleta: blanco papel, azul tinta, gris plomo, acento verde hoja.
   ========================================================================== */

/* --- Variables y reset --- */
:root {
  --color-ink: #1a1a2e;
  --color-ink-soft: #3d3d56;
  --color-paper: #fafaf7;
  --color-paper-warm: #f4f1eb;
  --color-accent: #2563eb;
  --color-accent-dark: #1d4ed8;
  --color-accent-muted: #dbeafe;
  --color-green: #16a34a;
  --color-border: #e5e2d9;
  --color-muted: #6b7280;

  --font-display: 'Fraunces', Georgia, 'Times New Roman', serif;
  --font-body: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'DM Mono', 'Courier New', monospace;

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --max-width: 720px;
  --max-width-wide: 900px;

  --transition: 160ms ease;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  background-color: var(--color-paper);
  color: var(--color-ink);
  line-height: 1.65;
  font-size: 1rem;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--color-accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* --- Tipografía base --- */
h1, h2, h3 {
  font-family: var(--font-display);
  line-height: 1.2;
  color: var(--color-ink);
}

h1 { font-size: clamp(2rem, 5vw, 2.75rem); font-weight: 700; }
h2 { font-size: clamp(1.4rem, 3.5vw, 1.9rem); font-weight: 600; }
h3 { font-size: clamp(1.1rem, 2.5vw, 1.3rem); font-weight: 600; }

p {
  max-width: 65ch;
  color: var(--color-ink-soft);
}

/* --- Layout principal --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-sm);
}

.container--wide {
  max-width: var(--max-width-wide);
}

section {
  padding: var(--space-xl) 0;
}

/* Separador visual entre secciones */
section + section {
  border-top: 1px solid var(--color-border);
}

/* --- Header mínimo --- */
.site-header {
  background: var(--color-paper);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-xs) 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
}

.site-logo {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-ink);
  letter-spacing: -0.02em;
}

.site-logo span {
  color: var(--color-accent);
}

/* --- Hero --- */
.hero {
  padding: var(--space-xl) 0 var(--space-lg);
  background: linear-gradient(160deg, #f0f4ff 0%, var(--color-paper) 60%);
  border-top: none;
}

.hero__eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  background: var(--color-accent-muted);
  padding: 4px 10px;
  border-radius: 99px;
  margin-bottom: var(--space-sm);
}

.hero__title {
  margin-bottom: var(--space-sm);
}

.hero__subtitle {
  font-size: 1.15rem;
  color: var(--color-ink-soft);
  margin-bottom: var(--space-md);
  max-width: 58ch;
}

.hero__intro {
  margin-bottom: var(--space-lg);
}

.hero__cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  align-items: center;
}

/* --- Botones --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 12px 22px;
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  white-space: nowrap;
  text-decoration: none;
}

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

.btn--primary:hover {
  background: var(--color-accent-dark);
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

.btn--secondary {
  background: transparent;
  color: var(--color-accent);
  border: 1.5px solid var(--color-accent);
}

.btn--secondary:hover {
  background: var(--color-accent-muted);
  text-decoration: none;
}

.btn--sm {
  font-size: 0.8rem;
  padding: 7px 14px;
}

/* Icono de flecha inline en botones */
.btn__arrow {
  font-style: normal;
  font-size: 1em;
}

/* --- Nota de contexto (debajo del hero CTA) --- */
.hero__note {
  font-size: 0.8rem;
  color: var(--color-muted);
  margin-top: var(--space-xs);
}

/* --- Sección: Definición --- */
.definition__content {
  display: grid;
  gap: var(--space-md);
}

.definition__highlight {
  background: var(--color-paper-warm);
  border-left: 3px solid var(--color-accent);
  padding: var(--space-sm) var(--space-md);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 1.05rem;
  color: var(--color-ink);
  font-style: italic;
}

/* --- Sección: Tabla gramajes --- */
.table-wrapper {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  margin: var(--space-md) 0;
}

/* H2: Tabla de gramajes — clave para H2 (CTR) */
.gramos-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  min-width: 520px;
}

.gramos-table thead {
  background: var(--color-ink);
  color: #fff;
}

.gramos-table thead th {
  padding: 12px 14px;
  text-align: left;
  font-weight: 600;
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.gramos-table tbody tr {
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition);
}

.gramos-table tbody tr:last-child {
  border-bottom: none;
}

.gramos-table tbody tr:hover {
  background: var(--color-accent-muted);
}

.gramos-table td {
  padding: 12px 14px;
  vertical-align: middle;
  color: var(--color-ink-soft);
}

.gramos-table td:first-child {
  font-weight: 700;
  color: var(--color-ink);
  font-family: var(--font-display);
  font-size: 1rem;
}

.badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 99px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.badge--popular {
  background: #dcfce7;
  color: #166534;
}

.badge--office {
  background: var(--color-accent-muted);
  color: #1e40af;
}

.badge--pro {
  background: #fef9c3;
  color: #854d0e;
}

/* --- Sección: Usos --- */
.uses-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  margin-top: var(--space-md);
}

@media (min-width: 540px) {
  .uses-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.use-card {
  background: var(--color-paper-warm);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.use-card__icon {
  font-size: 1.75rem;
  line-height: 1;
}

.use-card h3 {
  font-size: 1.05rem;
  margin-top: var(--space-xs);
}

.use-card p {
  font-size: 0.875rem;
  flex-grow: 1;
}

.use-card__cta {
  margin-top: var(--space-xs);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-accent);
}

.use-card__cta:hover {
  text-decoration: underline;
}

/* --- Sección: Comparativa --- */
.comparison-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  margin-top: var(--space-md);
}

@media (min-width: 600px) {
  .comparison-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.comparison-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.comparison-card__header {
  padding: var(--space-xs) var(--space-sm);
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.comparison-card--bond .comparison-card__header {
  background: var(--color-ink);
  color: #fff;
}

.comparison-card--other .comparison-card__header {
  background: var(--color-paper-warm);
  color: var(--color-muted);
}

.comparison-card__body {
  padding: var(--space-sm);
}

.comparison-card__body ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.comparison-card__body ul li {
  font-size: 0.875rem;
  color: var(--color-ink-soft);
  padding-left: 1.2em;
  position: relative;
}

.comparison-card--bond .comparison-card__body ul li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-green);
  font-weight: 700;
}

.comparison-card--other .comparison-card__body ul li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--color-muted);
}

/* --- Sección: FAQ --- */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  margin-top: var(--space-md);
}

.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.faq-item__question {
  width: 100%;
  background: #fff;
  border: none;
  padding: var(--space-sm) var(--space-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
  cursor: pointer;
  text-align: left;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-ink);
  transition: background var(--transition);
}

.faq-item__question:hover {
  background: var(--color-paper-warm);
}

.faq-item__icon {
  font-size: 1.2rem;
  line-height: 1;
  flex-shrink: 0;
  transition: transform var(--transition);
  color: var(--color-accent);
}

.faq-item[open] .faq-item__icon,
.faq-item.is-open .faq-item__icon {
  transform: rotate(45deg);
}

.faq-item__answer {
  padding: 0 var(--space-md) var(--space-sm);
  font-size: 0.9rem;
  color: var(--color-ink-soft);
  background: #fff;
  display: none;
}

.faq-item.is-open .faq-item__answer {
  display: block;
}

.faq-item__answer p + p {
  margin-top: 0.5em;
}

/* --- Footer --- */
.site-footer {
  background: var(--color-ink);
  color: rgba(255,255,255,0.65);
  padding: var(--space-lg) 0;
  margin-top: var(--space-xl);
  border-top: none;
}

.site-footer .container {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

@media (min-width: 600px) {
  .site-footer .container {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.footer-logo {
  font-family: var(--font-display);
  color: #fff;
  font-size: 1rem;
  font-weight: 700;
}

.footer-logo span { color: #93c5fd; }

.footer-note {
  font-size: 0.75rem;
  max-width: 45ch;
}

.footer-links {
  display: flex;
  gap: var(--space-sm);
  list-style: none;
}

.footer-links a {
  color: rgba(255,255,255,0.55);
  font-size: 0.8rem;
  transition: color var(--transition);
}

.footer-links a:hover {
  color: #fff;
  text-decoration: none;
}

/* --- Utilidades --- */
.section__intro {
  color: var(--color-ink-soft);
  margin-bottom: var(--space-md);
  max-width: 60ch;
}

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

.mt-sm { margin-top: var(--space-xs); }
.mt-md { margin-top: var(--space-sm); }

/* --- Accesibilidad --- */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: 3px;
}

/* Saltar al contenido (accesibilidad) */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-accent);
  color: #fff;
  padding: 8px 16px;
  z-index: 9999;
  font-size: 0.875rem;
  transition: top 0.1s;
}

.skip-link:focus {
  top: 0;
}

/* --- Animación de entrada suave --- */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero__eyebrow,
.hero__title,
.hero__subtitle,
.hero__intro,
.hero__cta-group {
  animation: fadeUp 0.45s ease both;
}

.hero__eyebrow  { animation-delay: 0.05s; }
.hero__title    { animation-delay: 0.12s; }
.hero__subtitle { animation-delay: 0.18s; }
.hero__intro    { animation-delay: 0.24s; }
.hero__cta-group{ animation-delay: 0.30s; }

/* Reducir movimiento para usuarios que lo prefieran */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}