/**
 * ╔══════════════════════════════════════════════════════════╗
 * ║  KLUE DIGITAL — iframe-optimizations.css                 ║
 * ║  Performance otimizada para iframes pesados              ║
 * ║  Lazy loading, skeleton, preconnect                      ║
 * ╚══════════════════════════════════════════════════════════╝
 */

/* ────────────────────────────────────────
   IFRAME CONTAINER OPTIMIZATION
   ──────────────────────────────────────── */

iframe {
  /* Prevenire parser blocking */
  display: block;
  border: none;
  
  /* Lazy load nativo */
  loading: lazy;
  
  /* Evitar reflow durante load */
  contain: layout style paint;
}

/* Dimensões pré-definidas para evitar layout shift */
.hero-browser-iframe {
  width: 100%;
  max-width: 600px;
  height: 360px;
  aspect-ratio: 16 / 9;
}

.km-frame-iframe {
  width: 100%;
  max-width: 800px;
  height: 500px;
  aspect-ratio: 16 / 10;
}

.site-preview-iframe {
  width: 100%;
  max-width: 900px;
  height: 600px;
  aspect-ratio: 3 / 2;
}

/* ────────────────────────────────────────
   SKELETON LOADING (Placeholder)
   ──────────────────────────────────────── */

iframe.loading::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    rgba(145, 43, 255, 0.05),
    rgba(145, 43, 255, 0.1),
    rgba(145, 43, 255, 0.05)
  );
  background-size: 200% 100%;
  animation: skeleton-loading 2s infinite;
  z-index: 1;
}

@keyframes skeleton-loading {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}

/* Loading indicator */
.iframe-container {
  position: relative;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(145, 43, 255, 0.1);
  border-radius: 8px;
  overflow: hidden;
}

.iframe-container.loading::after {
  content: 'Carregando...';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: rgba(145, 43, 255, 0.5);
  font-size: 14px;
  z-index: 2;
  pointer-events: none;
}

/* ────────────────────────────────────────
   IFRAME PERFORMANCE OPTIMIZATION
   ──────────────────────────────────────── */

.hero-browser-frame {
  /* Container do iframe no hero */
  position: relative;
  width: 100%;
  height: 300px;
  max-height: 400px;
  overflow: hidden;
  border-radius: 12px;
  background: linear-gradient(
    135deg,
    rgba(145, 43, 255, 0.05),
    rgba(145, 43, 255, 0.02)
  );
  border: 1px solid rgba(145, 43, 255, 0.1);
}

@media (min-width: 768px) {
  .hero-browser-frame {
    height: 400px;
  }
}

/* ────────────────────────────────────────
   LAZY LOAD DETECTION
   ──────────────────────────────────────── */

/* Mostrar loading enquanto carrega */
iframe:not([data-loaded="true"]) {
  opacity: 0.7;
  filter: blur(1px);
  transition: opacity 0.3s, filter 0.3s;
}

iframe[data-loaded="true"] {
  opacity: 1;
  filter: blur(0);
}

/* ────────────────────────────────────────
   SANDBOXING SEGURO (Performance + Security)
   ──────────────────────────────────────── */

/* Atributos de segurança não removem loading, 
   mas reduzem parsing overhead */
iframe {
  /* já adicionado via HTML sandbox attribute */
}

/* ────────────────────────────────────────
   MOBILE OPTIMIZATION
   ──────────────────────────────────────── */

@media (max-width: 768px) {
  .hero-browser-iframe {
    height: 240px;
  }

  .km-frame-iframe {
    height: 320px;
  }

  .site-preview-iframe {
    height: 350px;
  }

  /* Reduzir altura no mobile para economizar banda */
  .iframe-container {
    margin: 20px 0;
  }
}

/* ────────────────────────────────────────
   INTERSECTION OBSERVER READY
   ──────────────────────────────────────── */

/* Será controlado via JavaScript */
iframe {
  /* Placeholder até visible */
  background-image: linear-gradient(
    135deg,
    rgba(145, 43, 255, 0.05),
    rgba(145, 43, 255, 0.1)
  );
}

/* ────────────────────────────────────────
   FADE IN EFFECT
   ──────────────────────────────────────── */

@keyframes iframe-fade-in {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

iframe[data-loaded="true"] {
  animation: iframe-fade-in 0.6s ease-out;
}

/* ────────────────────────────────────────
   REDUCE CUMULATIVE LAYOUT SHIFT (CLS)
   ──────────────────────────────────────── */

/* Pré-alocar espaço para iframes */
.klue-menu-preview {
  aspect-ratio: 16 / 10;
}

.hero-browser-frame {
  aspect-ratio: 16 / 9;
}

.site-modal-frame {
  aspect-ratio: 3 / 2;
}

/* ────────────────────────────────────────
   PRINT OPTIMIZATION
   ──────────────────────────────────────── */

@media print {
  iframe {
    display: none;
  }
}

/* ────────────────────────────────────────
   DARKMODE IFRAME OVERLAY
   ──────────────────────────────────────── */

iframe {
  /* Filtro leve para melhor integração com dark mode */
  filter: brightness(0.95);
}

@media (prefers-color-scheme: light) {
  iframe {
    filter: brightness(1);
  }
}

/* ────────────────────────────────────────
   ACCESSIBILITY
   ──────────────────────────────────────── */

/* Screen readers devem ignorar iframes vazios */
iframe[src=""] {
  display: none;
}

/* ────────────────────────────────────────
   HIGH CONTRAST MODE
   ──────────────────────────────────────── */

@media (prefers-contrast: more) {
  .iframe-container {
    border-width: 2px;
    border-color: currentColor;
  }
}