body {
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
  color: #f5f7fb;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  margin: 0;
}

.card {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 12px;
  padding: 28px 32px;
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.25);
  backdrop-filter: blur(6px);
  max-width: 420px;
  width: 90%;
  text-align: center;
}

h1 {
  margin-top: 0;
  margin-bottom: 12px;
  font-size: 28px;
  letter-spacing: 0.5px;
}

p {
  margin: 0 0 20px;
  color: #e4e8f0;
  line-height: 1.5;
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 8px;
  text-align: left;
}

fieldset {
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 10px;
  padding: 14px 16px;
  margin-bottom: 18px;
  text-align: left;
}

legend {
  padding: 0 6px;
  font-weight: 700;
}

select {
  width: 100%;
  padding: 10px 12px;
  border-radius: 8px;
  border: none;
  margin-bottom: 18px;
  font-size: 15px;
}

button {
  background: #fbd38d;
  color: #1b2541;
  border: none;
  border-radius: 8px;
  padding: 12px 18px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.25);
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

#start-button {
  display: none;
  align-items: center;
  justify-content: center;
  margin: 12px auto 0;
}

.selectors {
  margin-top: 8px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 14px;
  padding: 14px;
  background: rgba(255, 255, 255, 0.04);
}

.accordion-toggle {
  width: 100%;
  background: transparent;
  color: #f5f7fb;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 10px;
  padding: 10px 12px;
  text-align: left;
  font-weight: 700;
  cursor: pointer;
  margin-bottom: 12px;
}

.accordion-toggle:hover {
  border-color: rgba(255, 255, 255, 0.3);
}

.selectors.collapsed #selectors-content {
  display: none;
}

.selectors fieldset {
  margin-bottom: 12px;
}

.selectors fieldset:last-of-type {
  margin-bottom: 0;
}

.hint {
  font-size: 12px;
  color: #d6e2f7;
  opacity: 0.85;
  margin-top: 4px;
}

.question-card {
  margin-top: 14px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 12px;
  padding: 16px;
  background: rgba(255, 255, 255, 0.05);
}

.question-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 1em;
}

#question-title, #answer-title {
  margin: 0;
  line-height: 1;
}

.question-subline {
  display: flex;
  justify-content: flex-start;
  align-items: center;
  margin-top: 0;
  margin-bottom: 6px;
}

.question-reference {
  display: inline-block;
  margin-top: 0;
  font-weight: 600;
  color: #d6e2f7;
}

.question-points {
  font-weight: 700;
  color: #fbd38d;
  font-size: 14px;
}

.question-text {
  margin: 8px 0 12px;
  line-height: 1.6;
  color: #f5f7fb;
}

.question-actions {
  display: flex;
  justify-content: space-between;
  gap: 8px;
}

.question-actions button {
  flex: 1;
}

.chapter-status {
  margin-left: 6px;
  font-size: 12px;
  color: #d6e2f7;
  opacity: 0.85;
}

.chapter-status.ready {
  color: #bbf7d0;
}

.chapter-status.downloading {
  color: #fbd38d;
}

.chapter-status.error {
  color: #f87171;
}

.chapter-status.not-downloaded {
  color: #d6e2f7;
}

.blanked-word {
  text-decoration: underline;
  font-weight: bold;
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

.hint-button {
  background: #68a9e8;
  color: #1b2541;
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 600;
  border-radius: 6px;
  white-space: nowrap;
}

.hint-button:hover {
  background: #7bb7f0;
}

.hint-button:disabled {
  background: #4a5568;
  color: #a0aec0;
}