/**
 * Premium 3D PDF Flipbook - FlipHTML5 Style
 * Dark cinematic theme, glass-morphism, production-ready
 */

:root {
  --bg-from: #0f0f0f;
  --bg-to: #1c1c1c;
  --glow-color: rgba(80, 120, 200, 0.15);
  --glass-bg: rgba(255, 255, 255, 0.06);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-hover: rgba(255, 255, 255, 0.12);
  --text-primary: rgba(255, 255, 255, 0.95);
  --text-secondary: rgba(255, 255, 255, 0.6);
  --accent: #5b9cf5;
  --accent-hover: #7ab3ff;
  --shadow-dark: rgba(0, 0, 0, 0.6);
  --max-book-width: 1400px;
}

/* Reset */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background: linear-gradient(135deg, var(--bg-from) 0%, var(--bg-to) 50%, #151515 100%);
  color: var(--text-primary);
  overflow-x: hidden;
  user-select: none;
  -webkit-user-select: none;
  -webkit-tap-highlight-color: transparent;
}

/* Radial glow behind book */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 50%, var(--glow-color) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

/* Particles */
.particles {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  overflow: hidden;
}

.particle {
  position: absolute;
  width: 4px;
  height: 4px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 50%;
  animation: float 20s infinite ease-in-out;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); opacity: 0.3; }
  25% { transform: translate(30px, -50px) scale(1.2); opacity: 0.5; }
  50% { transform: translate(-20px, 30px) scale(0.8); opacity: 0.2; }
  75% { transform: translate(40px, 20px) scale(1.1); opacity: 0.4; }
}

/* Loading */
.loading-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--bg-from) 0%, var(--bg-to) 100%);
  z-index: 9999;
  transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loading-overlay.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.loading-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.loading-spinner {
  width: 48px;
  height: 48px;
  border: 3px solid rgba(255, 255, 255, 0.1);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.loading-text {
  font-size: 0.95rem;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* App fade-in */
.app {
  position: relative;
  z-index: 2;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem 1rem;
  animation: fadeIn 0.8s ease-out;
}

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

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Pan viewport */
.pan-viewport {
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  flex: 1;
  min-height: 300px;
  cursor: grab;
  touch-action: none;
}

.pan-viewport.panning {
  cursor: grabbing;
}

.pan-viewport.zoom-1 {
  cursor: default;
}

/* Flipbook container */
.flipbook-container {
  position: relative;
  perspective: 2000px;
  padding: 2rem 0;
  transform-origin: center center;
  max-width: var(--max-book-width);
  transition: transform 0.15s ease-out;
}

.flipbook-container.panning {
  transition: none;
}

/* 3D Book - ortada çizgi yok, sayfalar birleşik */
.flipbook {
  position: relative;
  transform-style: preserve-3d;
  transform: rotateX(4deg) rotateY(-2deg);
  background: #fff;
  border-radius: 4px;
  overflow: visible;
  transition: transform 0.4s ease, box-shadow 0.4s ease;
  box-shadow:
    0 4px 8px var(--shadow-dark),
    0 20px 40px var(--shadow-dark),
    0 60px 120px rgba(0, 0, 0, 0.5);
}

.flipbook:hover {
  transform: rotateX(3deg) rotateY(-1deg);
  box-shadow:
    0 8px 16px var(--shadow-dark),
    0 30px 60px var(--shadow-dark),
    0 80px 160px rgba(0, 0, 0, 0.6);
}

.flipbook .shadow {
  display: none !important;
}

/* Pages - sıfır boşluk, sayfalar bitişik */
.flipbook .page {
  background: #fff !important;
  overflow: hidden !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  backface-visibility: hidden;
  margin: 0 !important;
  padding: 0 !important;
}

.flipbook .page-wrapper {
  background: #fff !important;
  margin: 0 !important;
  padding: 0 !important;
  box-sizing: border-box !important;
  isolation: isolate;
}

/* Sol sayfa (even) sağa doğru genişleyerek sağ sayfayla üst üste biner - sadece masaüstü */
@media (min-width: 769px) {
  .flipbook .page-wrapper:has(.page.even) {
    width: calc(50% + 30px) !important;
    left: 0 !important;
    right: auto !important;
  }
}

.flipbook .page canvas {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 0;
  padding: 0;
}

/* Glass panel - top right */
.glass-panel {
  position: fixed;
  top: 1.5rem;
  right: 1.5rem;
  z-index: 1000;
  padding-top: env(safe-area-inset-top);
}

.glass-panel-inner {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.5rem 0.75rem;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.glass-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  border-radius: 10px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

.glass-btn:hover {
  background: var(--glass-hover);
  color: var(--accent);
  transform: scale(1.05);
}

.glass-btn:active {
  transform: scale(0.98);
}

.glass-btn svg {
  width: 20px;
  height: 20px;
}

.glass-divider {
  width: 1px;
  height: 24px;
  background: var(--glass-border);
  margin: 0 0.25rem;
}

.page-indicator {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  min-width: 3.5rem;
  text-align: center;
  letter-spacing: 0.02em;
}

/* Page nav - bottom center */
.page-nav {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 0.5rem;
  z-index: 1000;
  padding-bottom: env(safe-area-inset-bottom);
}

.nav-btn {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.2);
}

.nav-btn:hover:not(:disabled) {
  background: var(--glass-hover);
  color: var(--accent);
  transform: scale(1.05);
}

.nav-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
  transform: none;
}

.nav-btn svg {
  width: 20px;
  height: 20px;
}

/* Thumbnail modal */
.thumbnail-modal {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.thumbnail-modal.visible {
  opacity: 1;
  visibility: visible;
}

.thumbnail-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(8px);
}

.thumbnail-content {
  position: relative;
  width: 100%;
  max-width: 900px;
  max-height: 85vh;
  background: rgba(26, 26, 26, 0.95);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.5);
  transform: scale(0.95);
  transition: transform 0.3s ease;
}

.thumbnail-modal.visible .thumbnail-content {
  transform: scale(1);
}

.thumbnail-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--glass-border);
}

.thumbnail-header h2 {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.thumbnail-loading {
  grid-column: 1 / -1;
  padding: 3rem;
  text-align: center;
  color: var(--text-secondary);
}

.thumbnail-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: 0.75rem;
  padding: 1.5rem;
  max-height: 70vh;
  overflow-y: auto;
}

.thumbnail-item {
  aspect-ratio: 3/4;
  background: #2a2a2a;
  border: 2px solid transparent;
  border-radius: 8px;
  overflow: hidden;
  cursor: pointer;
  transition: all 0.2s ease;
}

.thumbnail-item:hover {
  border-color: var(--accent);
  transform: scale(1.02);
}

.thumbnail-item.active {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent);
}

.thumbnail-item canvas,
.thumbnail-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* sr-only */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Responsive */
@media (max-width: 768px) {
  .glass-panel {
    top: 1rem;
    right: 1rem;
  }

  .glass-panel-inner {
    padding: 0.4rem 0.5rem;
    gap: 0.2rem;
  }

  .glass-btn {
    width: 36px;
    height: 36px;
  }

  .glass-btn svg {
    width: 18px;
    height: 18px;
  }

  .page-indicator {
    font-size: 0.8rem;
    min-width: 3rem;
  }

  .flipbook {
    transform: none;
  }

  .page-nav {
    bottom: 1rem;
  }

  .nav-btn {
    width: 44px;
    height: 44px;
  }

  .thumbnail-grid {
    grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
  }
}

@media (max-width: 380px) {
  .glass-btn {
    width: 32px;
    height: 32px;
  }

  .nav-btn {
    width: 40px;
    height: 40px;
  }
}