/*!
 * Enhanced Features Styles for TVXL Blog
 * Lazy loading, scroll to top, reading progress bar
 */

/* ===========================
   Lazy Loading Images
   =========================== */

/* Image while loading */
img[data-src] {
  filter: blur(5px);
  transition: filter 0.3s ease;
}

img.lazy-loading {
  opacity: 0.6;
}

img.lazy-loaded {
  filter: blur(0);
  opacity: 1;
}

img.lazy-error {
  opacity: 0.3;
  filter: grayscale(100%);
}

/* ===========================
   Scroll to Top Button
   =========================== */

.scroll-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background-color: var(--link-hover, #0085A1);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
  z-index: 999;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}

.scroll-to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

.scroll-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.scroll-to-top i {
  pointer-events: none;
}

/* Dark mode support */
[data-theme="dark"] .scroll-to-top {
  background-color: var(--link-hover, #4db8d8);
  box-shadow: 0 4px 12px rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .scroll-to-top:hover {
  box-shadow: 0 6px 16px rgba(255, 255, 255, 0.15);
}

/* Mobile adjustments */
@media (max-width: 768px) {
  .scroll-to-top {
    bottom: 20px;
    right: 20px;
    width: 45px;
    height: 45px;
    font-size: 18px;
  }
}

/* ===========================
   Reading Progress Bar
   =========================== */

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 3px;
  background: linear-gradient(to right, #0085A1, #00A8CC);
  z-index: 1000;
  transition: width 0.1s ease;
}

/* Dark mode support */
[data-theme="dark"] .reading-progress {
  background: linear-gradient(to right, #4db8d8, #5dcfe0);
}

/* Ensure it's above navbar when navbar is fixed */
.navbar-custom.is-fixed ~ .reading-progress {
  top: 0;
}

/* ===========================
   Loading Placeholder
   =========================== */

.image-placeholder {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: loading 1.5s ease-in-out infinite;
}

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

[data-theme="dark"] .image-placeholder {
  background: linear-gradient(90deg, #2a2a2a 25%, #353535 50%, #2a2a2a 75%);
  background-size: 200% 100%;
}