/* ═══════════════════════════════════════════════════════════════════════════
   FLIPBOOK VIEWER STYLES
   Uses CSS custom properties from styles.css
   ═══════════════════════════════════════════════════════════════════════════ */

/* Full-viewport layout */
html, body {
  margin: 0;
  padding: 0;
  overflow: hidden;
  height: 100%;
}

.flipbook-app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  background: var(--bg);
  background-image: var(--bg-gradient);
  color: var(--text);
  font-family: var(--font-body);
}

/* ── Top Bar ── */
.flipbook-topbar {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.625rem 1rem;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  z-index: 10;
  flex-shrink: 0;
}

.flipbook-back {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  color: var(--brand);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.875rem;
  white-space: nowrap;
  transition: opacity var(--transition-fast);
}

.flipbook-back:hover {
  opacity: 0.8;
}

.flipbook-title {
  flex: 1;
  text-align: center;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1rem;
  color: var(--text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* ── Shared Button Style ── */
.flipbook-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--glass-border);
  border-radius: 0.5rem;
  background: var(--surface-2);
  color: var(--text);
  cursor: pointer;
  font-size: 0.875rem;
  font-family: var(--font-body);
  transition: background var(--transition-fast), border-color var(--transition-fast);
  text-decoration: none;
}

.flipbook-btn:hover {
  background: var(--surface-3);
  border-color: var(--brand);
}

.flipbook-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.flipbook-btn:disabled:hover {
  background: var(--surface-2);
  border-color: var(--glass-border);
}

/* ── Loading State ── */
.flipbook-loading {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 2rem;
}

.flipbook-spinner {
  width: 48px;
  height: 48px;
  border: 3px solid var(--surface-3);
  border-top-color: var(--brand);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.flipbook-loading p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

.flipbook-progress-bar {
  width: 240px;
  max-width: 80%;
  height: 4px;
  background: var(--surface-3);
  border-radius: 2px;
  overflow: hidden;
}

.flipbook-progress-fill {
  height: 100%;
  width: 0%;
  background: var(--brand);
  border-radius: 2px;
  transition: width 200ms ease;
}

.flipbook-loading-percent {
  font-size: 0.8125rem;
  color: var(--muted);
}

/* ── Error State ── */
.flipbook-error[hidden] {
  display: none !important;
}

.flipbook-error {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 2rem;
  text-align: center;
  color: var(--text-secondary);
}

.flipbook-error svg {
  color: var(--muted);
}

.flipbook-error h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: var(--text);
}

.flipbook-error p {
  margin: 0;
  max-width: 400px;
}

/* ── Hidden attribute support (base styles.css may override) ── */
.flipbook-viewer[hidden],
.flipbook-controls[hidden] {
  display: none !important;
}

/* ── Viewer ── */
.flipbook-viewer {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
  min-height: 0;
}

.flipbook-container {
  display: flex;
  align-items: center;
  justify-content: center;
}

/* StPageFlip page styling */
.flipbook-container .stf__parent {
  margin: 0 auto;
}

.flipbook-page {
  background: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.flipbook-page canvas {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

/* ── Bottom Controls ── */
.flipbook-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.625rem 1rem;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-top: 1px solid var(--glass-border);
  z-index: 10;
  flex-shrink: 0;
}

.flipbook-page-display {
  min-width: 100px;
  text-align: center;
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-variant-numeric: tabular-nums;
}

/* ── Fullscreen ── */
.flipbook-app:fullscreen,
.flipbook-app:-webkit-full-screen {
  background: var(--bg);
  background-image: var(--bg-gradient);
}

/* ── Responsive ── */
@media (max-width: 640px) {
  .flipbook-topbar {
    padding: 0.5rem 0.75rem;
  }

  .flipbook-back span,
  .flipbook-back {
    font-size: 0.8125rem;
  }

  .flipbook-title {
    font-size: 0.875rem;
  }

  .flipbook-controls {
    gap: 0.25rem;
    padding: 0.5rem 0.5rem;
  }

  .flipbook-btn {
    padding: 0.4rem 0.5rem;
    font-size: 0.8125rem;
  }

  .flipbook-page-display {
    font-size: 0.8125rem;
    min-width: 80px;
  }
}