/**
 * DuplexDot - Double Stairs Preloader Stylesheet
 * Strictly Isolated Vanilla CSS
 * All selectors scoped under .duplex-loader
 * Zero generic tags (*, body, html, h1, etc.) outside .duplex-loader.
 */

/* 1. Main Fullscreen Preloader Container */
.duplex-loader {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100vh;
  z-index: 9999999;
  overflow: hidden;
  pointer-events: auto;
  user-select: none;
  background-color: #FFFFFF;
  box-sizing: border-box;
  opacity: 1;
  transition: opacity 0.5s ease;
}

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

/* 2. Inner Wrapper */
.duplex-loader .duplex-loader-inner {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

/* 3. Center Typography Stage & Background */
.duplex-loader .duplex-loader-center {
  position: absolute;
  inset: 0;
  z-index: 20;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  padding: 1.5rem;
  background-color: #FFFFFF;
  transition: opacity 0.35s cubic-bezier(0.76, 0, 0.24, 1);
}

.duplex-loader .duplex-loader-stage {
  position: relative;
  overflow: hidden;
  width: 100%;
  max-width: 900px;
  height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
}

@media (min-width: 640px) {
  .duplex-loader .duplex-loader-stage {
    height: 120px;
  }
}

@media (min-width: 1024px) {
  .duplex-loader .duplex-loader-stage {
    height: 140px;
  }
}

.duplex-loader .duplex-loader-text,
.duplex-loader .duplex-loader-word {
  position: absolute;
  font-family: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: clamp(2.2rem, 7vw, 5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  text-transform: uppercase;
  color: #1A6BFF;
  text-align: center;
  line-height: 1;
  user-select: none;
  white-space: nowrap;
  will-change: transform, opacity, filter;
  transition: transform 0.4s cubic-bezier(0.76, 0, 0.24, 1),
              opacity 0.4s cubic-bezier(0.76, 0, 0.24, 1),
              filter 0.4s cubic-bezier(0.76, 0, 0.24, 1);
}

.duplex-loader .duplex-loader-word-incoming {
  transform: translateY(110%);
  opacity: 0;
  filter: blur(6px);
  pointer-events: none;
}

.duplex-loader .duplex-loader-word-active {
  transform: translateY(0%);
  opacity: 1;
  filter: blur(0px);
  pointer-events: auto;
}

.duplex-loader .duplex-loader-word-outgoing {
  transform: translateY(-110%);
  opacity: 0;
  filter: blur(6px);
  pointer-events: none;
}

/* 4. Bottom Minimalist Progress Counter */
.duplex-loader .duplex-loader-progress {
  position: absolute;
  bottom: 2.5rem;
  left: 0;
  right: 0;
  z-index: 25;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  pointer-events: none;
  transition: opacity 0.35s ease;
}

.duplex-loader .duplex-loader-progress-track {
  width: 120px;
  height: 2px;
  background-color: rgba(26, 107, 255, 0.15);
  border-radius: 999px;
  overflow: hidden;
  position: relative;
}

.duplex-loader .duplex-loader-progress-fill {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 0%;
  background-color: #1A6BFF;
  transition: width 0.08s linear;
}

.duplex-loader .duplex-loader-progress-num {
  font-family: 'JetBrains Mono', ui-monospace, SFMono-Regular, monospace;
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: #1A6BFF;
  font-variant-numeric: tabular-nums;
}

/* 5. Dual Staircase Panels (Top & Bottom) */
.duplex-loader .duplex-loader-stairs-group {
  position: absolute;
  left: 0;
  right: 0;
  width: 100%;
  height: 50.5%;
  overflow: hidden;
  pointer-events: none;
  z-index: 10;
}

.duplex-loader .duplex-loader-stairs-top {
  top: 0;
}

.duplex-loader .duplex-loader-stairs-bottom {
  bottom: 0;
}

.duplex-loader .duplex-loader-panel {
  position: absolute;
  top: 0;
  bottom: 0;
  background-color: #1A6BFF;
  border-right: 1px solid rgba(255, 255, 255, 0.15);
  will-change: transform;
  transform: translateY(0%);
  transition-property: transform;
  transition-duration: 0.85s;
  transition-timing-function: cubic-bezier(0.76, 0, 0.24, 1);
}

/* Staircase Stagger Delays (5 Panels) */
.duplex-loader .duplex-loader-panel:nth-child(1) { --dd-stagger-exit: 0.00s; }
.duplex-loader .duplex-loader-panel:nth-child(2) { --dd-stagger-exit: 0.08s; }
.duplex-loader .duplex-loader-panel:nth-child(3) { --dd-stagger-exit: 0.16s; }
.duplex-loader .duplex-loader-panel:nth-child(4) { --dd-stagger-exit: 0.24s; }
.duplex-loader .duplex-loader-panel:nth-child(5) { --dd-stagger-exit: 0.32s; }

/* 6. Reveal & Exit State */
.duplex-loader.duplex-loader-revealing .duplex-loader-center {
  opacity: 0;
}

.duplex-loader.duplex-loader-revealing .duplex-loader-progress {
  opacity: 0;
}

.duplex-loader.duplex-loader-revealing .duplex-loader-stairs-top .duplex-loader-panel {
  transform: translateY(-100%);
  transition-delay: var(--dd-stagger-exit, 0s);
}

.duplex-loader.duplex-loader-revealing .duplex-loader-stairs-bottom .duplex-loader-panel {
  transform: translateY(100%);
  transition-delay: var(--dd-stagger-exit, 0s);
}

.duplex-loader.duplex-loader-hidden {
  opacity: 0;
  pointer-events: none;
}

/* 7. Reduced Motion Accessibility */
@media (prefers-reduced-motion: reduce) {
  .duplex-loader .duplex-loader-panel {
    transition: opacity 0.3s ease !important;
    transform: none !important;
  }
  .duplex-loader.duplex-loader-revealing .duplex-loader-panel {
    opacity: 0 !important;
    transform: none !important;
  }
  .duplex-loader .duplex-loader-word {
    transition: opacity 0.2s ease !important;
    transform: none !important;
    filter: none !important;
  }
}