:root {
  --viewer-bg: #f8f9fa;
  --viewer-surface: rgba(255, 255, 255, 0.97);
  --viewer-surface-muted: #f8f9fa;
  --viewer-text: #102535;
  --viewer-text-muted: rgba(16, 37, 53, 0.78);
  --viewer-accent: #7f888e;
  --viewer-accent-hover: #7f888e;
  --viewer-active: #2f8f5b;
  --viewer-border: rgba(38, 75, 102, 0.14);
  --viewer-canvas-border: rgba(38, 75, 102, 0.1);
  --viewer-toolbar-shadow: 0 4px 14px rgba(17, 24, 39, 0.08);
  --viewer-canvas-shadow: 0 8px 24px rgba(17, 24, 39, 0.12);
  --viewer-radius: 0.5rem;
  --viewer-transition: 0.2s ease;
}

body.viewer-body {
  margin: 0;
  background: var(--viewer-bg);
  color: var(--viewer-text);
  font-family: Arial, sans-serif;
}

.viewer-toolbar {
  position: sticky;
  top: 0;
  z-index: 20;
  padding: 0.65rem 0.75rem;
  background: var(--viewer-surface);
  border-bottom: 1px solid var(--viewer-border);
  box-shadow: var(--viewer-toolbar-shadow);
  backdrop-filter: blur(8px);
}

.viewer-toolbar-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.viewer-extra-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.viewer-btn {
  min-height: 2.1rem;
  padding: 0.35rem 0.7rem;
  font-weight: 600;
  line-height: 1.2;
  white-space: nowrap;
}

.viewer-btn.is-active {
  background: var(--viewer-active);
  border-color: var(--viewer-active);
  color: #ffffff;
}

.viewer-btn-secondary {
  background: var(--viewer-accent);
  border-color: var(--viewer-accent);
  color: #ffffff;
}

.viewer-btn-secondary:hover:not(:disabled),
.viewer-btn-secondary:focus-visible:not(:disabled) {
  background: var(--viewer-accent-hover);
  border-color: var(--viewer-accent-hover);
  color: #ffffff;
}

.viewer-toggle-label {
  pointer-events: none;
}

.viewer-toggle-icon {
  display: inline-block;
  width: 0.65rem;
  height: 0.65rem;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(-135deg);
  transition: transform var(--viewer-transition);
  pointer-events: none;
}

.viewer-toggle-icon-left {
  margin-right: 0.45rem;
}

.viewer-toggle-icon-right {
  margin-left: 0.45rem;
}

#toggle-controls.is-collapsed .viewer-toggle-icon {
  transform: rotate(45deg);
}

.viewer-toolbar-status {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  min-height: 2.1rem;
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--viewer-border);
  border-radius: var(--viewer-radius);
  background: var(--viewer-surface-muted);
  font-size: 0.92rem;
  font-weight: 600;
  text-align: center;
  white-space: nowrap;
}

.viewer-status-label {
  color: var(--viewer-text-muted);
}

.viewer-page-jump {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  margin: 0;
}

.viewer-page-input {
  width: 4.75rem;
  min-height: 2.1rem;
}

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

.viewer-wrap {
  padding: 1rem;
  width: 100%;
  min-height: calc(100vh - 7rem);
  overflow: auto;
  touch-action: pan-x pan-y;
  box-sizing: border-box;
}

.viewer-wrap.is-pinching {
  touch-action: none;
}

.viewer-stage {
  width: fit-content;
  max-width: 100%;
  margin: 0 auto;
}

#pdf-canvas {
  display: block;
  background: #ffffff;
  border: 1px solid var(--viewer-canvas-border);
  border-radius: var(--viewer-radius);
  box-shadow: var(--viewer-canvas-shadow);
}

@media (max-width: 991.98px) {
  .viewer-toolbar {
    padding: 0.6rem;
  }

  .viewer-toolbar-row {
    justify-content: stretch;
  }

  .viewer-toolbar-row > .viewer-btn,
  .viewer-toolbar-row > .viewer-toolbar-status,
  .viewer-toolbar-row > .viewer-page-jump,
  .viewer-toolbar-row > .viewer-extra-controls,
  .viewer-toolbar-row > .d-lg-none {
    flex: 1 1 calc(50% - 0.5rem);
  }

  .viewer-toolbar-status,
  .viewer-page-jump,
  .viewer-extra-controls {
    justify-content: center;
  }

  .viewer-page-jump {
    width: 100%;
  }

  .viewer-page-input {
    flex: 1 1 auto;
    width: auto;
  }

  .viewer-extra-controls {
    width: 100%;
  }

  .viewer-wrap {
    min-height: calc(100vh - 10rem);
    padding: 0.75rem;
  }
}

@media (max-width: 575.98px) {
  .viewer-toolbar {
    padding: 0;
  }

  .viewer-toolbar .container-fluid {
    padding-right: 0 !important;
    padding-left: 0 !important;
  }

  .viewer-btn,
  .viewer-toolbar-status,
  .viewer-page-input {
    min-height: 2.4rem;
    font-size: 0.9rem;
  }

  #toggle-controls {
    display: block;
    width: 100%;
    margin: 0;
    border-radius: 0;
    text-align: center;
  }

  #viewer-collapsible-controls {
    padding: 0.6rem;
  }

  .viewer-toolbar-row > .viewer-btn,
  .viewer-toolbar-row > .viewer-toolbar-status,
  .viewer-toolbar-row > .viewer-page-jump,
  .viewer-toolbar-row > .viewer-extra-controls,
  .viewer-toolbar-row > .d-lg-none {
    flex-basis: 100%;
  }

  .viewer-extra-controls {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.5rem;
  }

  .viewer-extra-controls > .viewer-btn {
    width: 100%;
  }

  .viewer-extra-controls #zoom-out,
  .viewer-extra-controls #zoom-in,
  .viewer-extra-controls #fit-width,
  .viewer-extra-controls #fit-height {
    grid-column: span 1;
  }

  .viewer-extra-controls #reset-fit {
    grid-column: 1/-1;
  }
}

@media print {
  .viewer-toolbar {
    display: none !important;
  }

  #pdf-canvas {
    filter: blur(12px);
  }

  body::before {
    content: "Printing from the viewer is disabled. If you have purchased this resource, please use the download button and print the downloaded PDF.";
    display: block;
    padding: 40px;
    font-size: 18px;
    line-height: 1.5;
    text-align: center;
  }
}