body {
  background-color: #1a1a1a;
  color: #ffffff;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  text-align: center;
}

.container {
  background-color: #242424;
  padding: 2rem 3rem;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.25);
}

h1 {
  margin-top: 0;
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 2rem;
}

.button-container {
  display: flex;
  gap: 1rem;
}

button {
  font-size: 1.2rem;
  padding: 0.8rem 1.5rem;
  border-radius: 8px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color 0.2s, border-color 0.2s;
  background-color: #3f3f3f;
  color: #ffffff;
  font-weight: 500;
}

button:hover {
  background-color: #535353;
  border-color: #747474;
}

button:active {
  transform: scale(0.98);
}

/* Main App Layout */
#main-app-container {
  display: none;
  flex-direction: column;
  width: 100%;
  height: 100%;
  max-width: 1200px;
  margin: 0 auto;
  background-color: #1a1a1a;
}

.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background-color: #242424;
  border-bottom: 1px solid #3f3f3f;
  width: 100%;
  box-sizing: border-box;
}

.app-title {
  font-size: 1.5rem;
  margin: 0;
}

.user-info {
  font-size: 1rem;
  font-weight: 500;
}

.app-main {
  flex-grow: 1;
  padding: 2rem;
  overflow-y: auto;
  text-align: left;
}

.app-main h2 {
    margin-top: 0;
}

.book-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1.5rem;
}

.app-footer {
  padding: 1rem 2rem;
  background-color: #242424;
  border-top: 1px solid #3f3f3f;
  text-align: center;
  font-size: 0.9rem;
  color: #888;
  width: 100%;
  box-sizing: border-box;
}

/* Book Card Styling */
.book-card {
  background-color: #242424;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  transition: transform 0.2s, box-shadow 0.2s;
  cursor: pointer;
  display: flex;
  flex-direction: column;
}

.book-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 12px rgba(0,0,0,0.2);
}

.book-card img {
  width: 100%;
  height: auto;
  aspect-ratio: 200 / 280;
  background-color: #3f3f3f;
}

.book-card .book-title {
  font-size: 1rem;
  font-weight: 600;
  margin: 0.75rem 0.75rem 0.25rem;
  color: #ffffff;
  flex-grow: 1;
}

.book-card .book-category {
  font-size: 0.8rem;
  margin: 0 0.75rem 0.75rem;
  color: #a0a0a0;
}

/* Quiz View Styling */
#quiz-container {
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem;
  background-color: #242424;
  border-radius: 12px;
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
}

.quiz-header h2 {
  font-size: 1.5rem;
  margin: 0;
  text-align: center;
  flex-grow: 1;
}

#quiz-timer {
  font-size: 1.2rem;
  font-weight: bold;
  color: #ffc107;
}

.quiz-question {
  font-size: 1.5rem;
  font-weight: 500;
  margin-bottom: 2rem;
  text-align: center;
}

.quiz-options {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.quiz-option {
  width: 100%;
  text-align: left;
  padding: 1rem;
  background-color: #3f3f3f;
  border: 1px solid #535353;
}

.quiz-option:hover {
  background-color: #535353;
  border-color: #747474;
}

.quiz-result {
  text-align: center;
}

.quiz-result h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.quiz-result p {
  font-size: 1.2rem;
  margin-bottom: 2rem;
}

#back-to-list {
  font-size: 1.2rem;
  padding: 0.8rem 2rem;
}

/* Vero Toast Styling */
.vero-toast {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background-color: rgba(0, 0, 0, 0.85);
  color: white;
  padding: 1rem 1.5rem;
  border-radius: 12px;
  display: flex;
  align-items: center;
  gap: 1rem;
  z-index: 1000;
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
  border: 1px solid #444;
}

#vero-face {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  object-fit: cover;
}

#vero-message {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 500;
}