body {
  margin: 0;
  font-family: 'Inter', Arial, sans-serif;
  background: #f7f8fa;
  color: #222;
}
#pdf-turner-root {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  justify-content: center;
  align-items: center;
}
#viewer-container {
  position: relative;
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 4px 32px rgba(0,0,0,0.10);
  margin-top: 40px;
  margin-bottom: 24px;
  width: 90vw;
  max-width: 900px;
  height: 70vh;
  min-height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
}
#pdf-viewer {
  width: 100%;
  height: 100%;
  overflow: hidden;
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}
.center-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 10;
  padding: 18px 48px;
  font-size: 1.2rem;
  background: #222;
  color: #fff;
  border: none;
  border-radius: 32px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  cursor: pointer;
  opacity: 0.95;
  transition: background 0.2s, box-shadow 0.2s;
}
.center-btn:hover {
  background: #444;
  box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}
.nav-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 10;
  width: 48px;
  height: 48px;
  background: rgba(34,34,34,0.85);
  color: #fff;
  border: none;
  border-radius: 50%;
  font-size: 2rem;
  cursor: pointer;
  opacity: 0.85;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s, box-shadow 0.2s;
}
.nav-arrow.left { left: 16px; }
.nav-arrow.right { right: 16px; }
.nav-arrow:hover {
  background: #111;
  opacity: 1;
}
#bottom-bar {
  width: 90vw;
  max-width: 900px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #fff;
  border-radius: 0 0 16px 16px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
  padding: 12px 24px;
  margin-bottom: 24px;
}
#attribution a {
  color: #1a73e8;
  text-decoration: none;
  font-size: 1rem;
  font-weight: 500;
  transition: color 0.2s;
}
#attribution a:hover {
  color: #0d47a1;
  text-decoration: underline;
}
#zoom-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}
#zoom-controls button {
  background: #f0f0f0;
  border: none;
  border-radius: 8px;
  font-size: 1.2rem;
  width: 36px;
  height: 36px;
  cursor: pointer;
  color: #222;
  transition: background 0.2s;
}
#zoom-controls button:hover {
  background: #e0e0e0;
}
#zoom-slider {
  width: 120px;
  accent-color: #1a73e8;
}
@media (max-width: 600px) {
  #viewer-container, #bottom-bar {
    width: 98vw;
    max-width: 100vw;
    padding: 0 2vw;
  }
  #bottom-bar {
    padding: 8px 8px;
  }
}