/* Nguyenvinhcypher.com — overlay được bật ngay từ đầu tài liệu và mở khóa khi lượt tải đầu ổn định. */
.ngvc-page-loader {
  position: fixed;
  inset: 0;
  z-index: 2147483647;
  display: none !important;
  align-items: center;
  justify-content: center;
  box-sizing: border-box;
  width: 100%;
  min-height: 100vh;
  padding: 24px;
  margin: 0;
  border: 0;
  background: rgba(0, 0, 0, .75);
  color: transparent;
  font: inherit;
  letter-spacing: normal;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  cursor: progress;
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
  transition: opacity .18s ease, visibility .18s ease;
}
/* A loader can appear only when JS explicitly adds ngvc-loader-visible. */
html.ngvc-loader-visible .ngvc-page-loader {
  display: flex !important;
  opacity: 1;
  visibility: visible;
  pointer-events: auto !important;
}
html.ngvc-loader-visible,
html.ngvc-loader-visible body {
  overflow: hidden !important;
  overscroll-behavior: none !important;
  touch-action: none !important;
  scroll-behavior: auto !important;
}
/* Older style.css versions set body pointer-events:none for this class;
   explicitly override it while the real overlay captures the input. */
html.ngvc-page-loading body,
html.ngvc-loader-visible body {
  pointer-events: auto !important;
}
html.ngvc-loader-visible.ngvc-loader-finished .ngvc-page-loader {
  opacity: 0;
  visibility: hidden;
  pointer-events: none !important;
}
.ngvc-loader-logo {
  position: relative;
  width: 140px;
  height: 140px;
  flex: 0 0 auto;
  animation: ngvcLoaderGroupSpin 2.5s cubic-bezier(.4, 0, .2, 1) infinite;
}
.ngvc-loader-triangle-svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
}
.ngvc-loader-path-left { animation: ngvcLoaderGatherLeft 2.5s cubic-bezier(.4, 0, .2, 1) infinite; }
.ngvc-loader-path-right { animation: ngvcLoaderGatherRight 2.5s cubic-bezier(.4, 0, .2, 1) infinite; }
.ngvc-loader-path-bottom { animation: ngvcLoaderGatherBottom 2.5s cubic-bezier(.4, 0, .2, 1) infinite; }
@keyframes ngvcLoaderGroupSpin {
  0% { transform: rotate(0deg); }
  50% { transform: rotate(180deg); }
  100% { transform: rotate(360deg); }
}
@keyframes ngvcLoaderGatherLeft {
  0% { transform: translate(-8px, -4.5px); }
  50% { transform: translate(0, 0); }
  100% { transform: translate(-8px, -4.5px); }
}
@keyframes ngvcLoaderGatherRight {
  0% { transform: translate(8px, -4.5px); }
  50% { transform: translate(0, 0); }
  100% { transform: translate(8px, -4.5px); }
}
@keyframes ngvcLoaderGatherBottom {
  0% { transform: translate(0, 9px); }
  50% { transform: translate(0, 0); }
  100% { transform: translate(0, 9px); }
}
img.ngvc-image-retrying,
img.ngvc-image-unavailable { visibility: hidden !important; }
@media (max-width: 420px) {
  .ngvc-loader-logo { width: 128px; height: 128px; }
}
@media (prefers-reduced-motion: reduce) {
  .ngvc-loader-logo,
  .ngvc-loader-path-left,
  .ngvc-loader-path-right,
  .ngvc-loader-path-bottom { animation: none; }
  .ngvc-page-loader { transition: none; }
}