/* Enhanced DoubtGuru Styles with User Profile Dropdown and Mobile Optimizations */
:root {
  /* Brand Colors */
  --primary-color: #2563eb;
  --primary-dark: #1d4ed8;
  --secondary-color: #10b981;
  --accent-color: #f59e0b;
  --success-color: #059669;
  --error-color: #dc2626;
  --warning-color: #d97706;

  /* Neutral Colors */
  --background: #f8fafc;
  --surface: #ffffff;
  --surface-hover: #f1f5f9;
  --border: #e2e8f0;
  --border-light: #f1f5f9;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;

  /* Transitions */
  --transition: all 0.2s ease-in-out;
  --transition-slow: all 0.3s ease-in-out;
}

[data-theme="dark"] {
  --background: #0f172a;
  --surface: #1e293b;
  --surface-hover: #334155;
  --border: #334155;
  --border-light: #475569;
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
}

/* Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--background);
  color: var(--text-primary);
  line-height: 1.6;
  font-size: 14px;
  transition: var(--transition);
}

/* Header */
.header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  height: 60px;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.logo i {
  font-size: 1.5rem;
  color: var(--primary-color);
}

.logo-text h1 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-color);
  line-height: 1;
}

.tagline {
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

/* User Profile Dropdown */
.user-profile-dropdown {
  position: relative;
}

.profile-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-xs) var(--spacing-sm);
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
}

.profile-btn:hover {
  background: var(--surface-hover);
  border-color: var(--primary-color);
}

.user-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  object-fit: cover;
}

.user-name {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-primary);
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: var(--spacing-xs);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  min-width: 280px;
  z-index: 1000;
  display: none;
}

.dropdown-menu.show {
  display: block;
}

.dropdown-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--border);
}

.dropdown-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  object-fit: cover;
}

.dropdown-user-info {
  flex: 1;
}

.dropdown-name {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-xs);
}

.dropdown-email {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.dropdown-divider {
  height: 1px;
  background: var(--border);
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  width: 100%;
  padding: var(--spacing-md) var(--spacing-lg);
  background: none;
  border: none;
  text-align: left;
  cursor: pointer;
  transition: var(--transition);
  color: var(--text-primary);
  font-size: 0.875rem;
}

.dropdown-item:hover {
  background: var(--surface-hover);
}

.logout-item {
  color: var(--error-color);
}

.logout-item:hover {
  background: rgba(220, 38, 38, 0.1);
}

.control-btn {
  width: 36px;
  height: 36px;
  border: 1px solid var(--border);
  background: var(--surface);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  color: var(--text-secondary);
}

.control-btn:hover {
  background: var(--surface-hover);
  border-color: var(--primary-color);
  color: var(--primary-color);
}

.login-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--primary-color);
  background: var(--primary-color);
  color: white;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 500;
  transition: var(--transition);
}

.login-btn:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

/* Free Questions Counter */
.free-questions-counter {
  background: linear-gradient(135deg, var(--accent-color), var(--warning-color));
  color: white;
  padding: var(--spacing-sm) 0;
  text-align: center;
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow);
}

.counter-content {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
}

.counter-content i {
  font-size: 1rem;
}

/* Main Container */
.main-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-lg) var(--spacing-md);
  min-height: calc(100vh - 140px);
}

/* Subjects Section */
.subjects-section {
  margin-bottom: var(--spacing-xl);
}

.subjects-container {
  position: relative;
}

.subjects-grid {
  display: flex;
  gap: var(--spacing-sm);
  overflow-x: auto;
  padding: var(--spacing-sm) 0;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.subjects-grid::-webkit-scrollbar {
  display: none;
}

.subject-btn {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-md);
  min-width: 80px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.subject-btn:hover {
  background: var(--surface-hover);
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.subject-btn.active {
  background: var(--primary-color);
  border-color: var(--primary-color);
  color: white;
  box-shadow: var(--shadow-md);
}

.subject-btn i {
  font-size: 1.25rem;
}

.subject-btn span {
  font-size: 0.75rem;
  font-weight: 500;
  line-height: 1.2;
}

/* Question Section */
.question-section {
  margin-bottom: var(--spacing-xl);
}

.question-container {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow);
}

.question-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-lg);
}

.question-header h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
}

.image-upload-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--accent-color);
  color: white;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 500;
  transition: var(--transition);
}

.image-upload-btn:hover {
  background: var(--warning-color);
  transform: translateY(-1px);
}

.question-input-container {
  margin-bottom: var(--spacing-lg);
}

#questionInput {
  width: 100%;
  min-height: 100px;
  padding: var(--spacing-md);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--background);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.875rem;
  resize: vertical;
  transition: var(--transition);
}

#questionInput:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.image-preview {
  margin-top: var(--spacing-md);
  position: relative;
  display: inline-block;
}

.image-preview img {
  max-width: 200px;
  max-height: 200px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.remove-image-btn {
  position: absolute;
  top: -8px;
  right: -8px;
  width: 24px;
  height: 24px;
  background: var(--error-color);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  box-shadow: var(--shadow);
}

.question-actions {
  display: flex;
  gap: var(--spacing-md);
  align-items: center;
}

/* Small Clear Button */
.clear-btn-small {
  width: 40px;
  height: 40px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: var(--transition);
  flex-shrink: 0;
}

.clear-btn-small:hover {
  background: var(--error-color);
  border-color: var(--error-color);
  color: white;
}

.submit-btn {
  flex: 1;
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  font-size: 0.875rem;
  font-weight: 600;
  transition: var(--transition);
}

.submit-btn:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.submit-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

/* Loading Section */
.loading-section {
  text-align: center;
  padding: var(--spacing-2xl);
}

.loading-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-lg);
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border);
  border-top: 3px solid var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

/* Answer Section */
.answer-section {
  margin-bottom: var(--spacing-xl);
}

.answer-container {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow);
}

.answer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--border);
}

.answer-header h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--primary-color);
}

.answer-actions {
  display: flex;
  gap: var(--spacing-xs);
}

.action-btn {
  width: 36px;
  height: 36px;
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: var(--transition);
}

.action-btn:hover {
  background: var(--primary-color);
  border-color: var(--primary-color);
  color: white;
}

.answer-content {
  line-height: 1.7;
  font-size: 0.875rem;
}

.answer-content h1,
.answer-content h2,
.answer-content h3 {
  margin: var(--spacing-lg) 0 var(--spacing-md) 0;
  color: var(--primary-color);
}

.answer-content p {
  margin-bottom: var(--spacing-md);
}

.answer-content ul,
.answer-content ol {
  margin: var(--spacing-md) 0;
  padding-left: var(--spacing-xl);
}

.answer-content li {
  margin-bottom: var(--spacing-xs);
}

.answer-content code {
  background: var(--background);
  padding: 0.125rem 0.25rem;
  border-radius: var(--radius-sm);
  font-family: "Courier New", monospace;
  font-size: 0.8125rem;
  border: 1px solid var(--border);
}

.answer-content pre {
  background: var(--background);
  padding: var(--spacing-md);
  border-radius: var(--radius);
  overflow-x: auto;
  border: 1px solid var(--border);
  margin: var(--spacing-md) 0;
}

/* History Section */
.history-section {
  margin-bottom: var(--spacing-xl);
}

.history-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-lg);
}

.history-header h3 {
  font-size: 1.125rem;
  font-weight: 600;
}

.history-container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.history-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  cursor: pointer;
  transition: var(--transition);
  position: relative;
}

.history-item:hover {
  background: var(--surface-hover);
  border-color: var(--primary-color);
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

.history-item-content {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--spacing-md);
}

.history-question {
  font-weight: 500;
  margin-bottom: var(--spacing-xs);
  color: var(--text-primary);
  font-size: 0.875rem;
  flex: 1;
}

.history-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
}

.history-subject {
  background: var(--primary-color);
  color: white;
  padding: 0.125rem var(--spacing-xs);
  border-radius: var(--radius-sm);
  font-size: 0.6875rem;
  font-weight: 500;
}

.delete-history-btn {
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  width: 24px;
  height: 24px;
  background: var(--error-color);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  opacity: 0;
  transition: var(--transition);
}

.history-item:hover .delete-history-btn {
  opacity: 1;
}

.delete-history-btn:hover {
  background: #b91c1c;
  transform: scale(1.1);
}

.no-history {
  text-align: center;
  padding: var(--spacing-2xl);
  color: var(--text-muted);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
}

.no-history i {
  font-size: 2rem;
  margin-bottom: var(--spacing-md);
  opacity: 0.5;
}

.history-login-warning {
  text-align: center;
  padding: var(--spacing-xl);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
}

.history-login-warning i {
  font-size: 2rem;
  color: var(--warning-color);
  margin-bottom: var(--spacing-md);
}

.history-login-warning p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
}

.history-login-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 500;
  transition: var(--transition);
}

.history-login-btn:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

/* Reviews Section */
.reviews-section {
  margin-bottom: var(--spacing-xl);
}

.reviews-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-lg);
}

.reviews-header h3 {
  font-size: 1.125rem;
  font-weight: 600;
}

.add-review-btn {
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--secondary-color);
  color: white;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: 0.8125rem;
  font-weight: 500;
  transition: var(--transition);
}

.add-review-btn:hover {
  background: var(--success-color);
}

.reviews-container {
  display: flex;
  gap: var(--spacing-md);
  overflow-x: auto;
  padding: var(--spacing-sm) 0;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.reviews-container::-webkit-scrollbar {
  display: none;
}

.review-card {
  flex-shrink: 0;
  width: 280px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.review-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.review-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-md);
}

.review-name {
  font-weight: 600;
  font-size: 0.875rem;
}

.review-class {
  font-size: 0.75rem;
  color: var(--text-secondary);
  background: var(--background);
  padding: 0.125rem var(--spacing-xs);
  border-radius: var(--radius-sm);
}

.review-rating {
  color: var(--accent-color);
  font-size: 0.875rem;
}

.review-message {
  color: var(--text-secondary);
  font-size: 0.8125rem;
  line-height: 1.5;
  margin-bottom: var(--spacing-md);
}

.review-date {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-align: right;
}

.loading-reviews {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  padding: var(--spacing-2xl);
  color: var(--text-secondary);
}

/* Footer */
.footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  margin-top: auto;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-lg) var(--spacing-md) var(--spacing-md);
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-md);
}

.footer-links {
  display: flex;
  gap: var(--spacing-lg);
}

.footer-links a {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.8125rem;
  font-weight: 500;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--primary-color);
}

.footer-links i {
  font-size: 0.875rem;
}

.developer-credit {
  text-align: right;
  font-size: 0.8125rem;
  color: var(--text-secondary);
}

.developer-credit strong {
  color: var(--primary-color);
  font-weight: 600;
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Modal Styles */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  backdrop-filter: blur(4px);
}

.modal-no-close {
  pointer-events: none;
}

.modal-no-close .modal-content {
  pointer-events: all;
}

.modal-content {
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  max-width: 480px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--border);
}

.modal-header h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--primary-color);
}

.close-modal {
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: var(--transition);
}

.close-modal:hover {
  background: var(--background);
  color: var(--text-primary);
}

/* Login Required Modal Styles */
.login-content {
  text-align: center;
}

.login-message {
  margin-bottom: var(--spacing-xl);
}

.login-message i {
  font-size: 3rem;
  color: var(--warning-color);
  margin-bottom: var(--spacing-md);
}

.login-message h4 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

.login-message p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
}

.premium-features {
  list-style: none;
  text-align: left;
  margin: var(--spacing-lg) 0;
}

.premium-features li {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) 0;
  color: var(--text-secondary);
}

.premium-features i {
  color: var(--success-color);
  font-size: 1rem;
}

.google-login-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  background: #4285f4;
  color: white;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 1rem;
  font-weight: 600;
  transition: var(--transition);
  margin-bottom: var(--spacing-md);
}

.google-login-btn:hover {
  background: #3367d6;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.login-note {
  color: var(--text-muted);
  font-size: 0.75rem;
  margin: 0;
}

/* Form Styles */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-sm);
  font-weight: 500;
  font-size: 0.875rem;
  color: var(--text-primary);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: var(--spacing-md);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--background);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.875rem;
  transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group textarea {
  min-height: 80px;
  resize: vertical;
}

.star-rating {
  display: flex;
  gap: var(--spacing-xs);
  margin: var(--spacing-sm) 0;
}

.star {
  font-size: 1.5rem;
  cursor: pointer;
  transition: var(--transition);
  opacity: 0.3;
}

.star.active,
.star:hover {
  opacity: 1;
  transform: scale(1.1);
}

.setup-submit-btn,
.settings-save-btn,
.review-submit-btn,
.suggestion-submit-btn {
  width: 100%;
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-weight: 600;
  font-size: 0.875rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  transition: var(--transition);
}

.setup-submit-btn:hover,
.settings-save-btn:hover,
.review-submit-btn:hover,
.suggestion-submit-btn:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* Video Modal */
.video-container {
  margin-bottom: var(--spacing-lg);
}

#howToUseVideo {
  width: 100%;
  max-height: 300px;
  border-radius: var(--radius);
}

.video-description h4 {
  margin-bottom: var(--spacing-md);
  color: var(--primary-color);
  font-size: 1rem;
}

.video-description ol {
  padding-left: var(--spacing-lg);
}

.video-description li {
  margin-bottom: var(--spacing-sm);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* Toast Notification */
.toast {
  position: fixed;
  bottom: var(--spacing-lg);
  right: var(--spacing-lg);
  background: var(--surface);
  color: var(--text-primary);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
  transform: translateX(100%);
  transition: var(--transition-slow);
  z-index: 2000;
  max-width: 320px;
  font-size: 0.875rem;
  font-weight: 500;
}

.toast.show {
  transform: translateX(0);
}

.toast.success {
  border-left: 4px solid var(--success-color);
}

.toast.error {
  border-left: 4px solid var(--error-color);
}

.toast.warning {
  border-left: 4px solid var(--warning-color);
}

/* Mobile Responsive Design */
@media (max-width: 768px) {
  .main-container {
    padding: var(--spacing-md) 0;
  }

  .header-content {
    padding: 0 var(--spacing-sm);
  }

  .header-controls {
    gap: var(--spacing-xs);
  }

  .user-name {
    display: none;
  }

  .login-btn span {
    display: none;
  }

  .login-btn {
    width: 36px;
    height: 36px;
    padding: 0;
    justify-content: center;
  }

  .logo-text h1 {
    font-size: 1.125rem;
  }

  .tagline {
    font-size: 0.6875rem;
  }

  .subjects-grid {
    gap: var(--spacing-xs);
    padding: var(--spacing-sm);
  }

  .subject-btn {
    min-width: 70px;
    padding: var(--spacing-sm);
  }

  .subject-btn i {
    font-size: 1.125rem;
  }

  .subject-btn span {
    font-size: 0.6875rem;
  }

  /* Mobile Question Container - Full Width */
  .question-container {
    margin: 0 -1rem;
    border-radius: 0;
    border-left: none;
    border-right: none;
  }

  .question-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-md);
  }

  .question-header h2 {
    font-size: 1.125rem;
  }

  #questionInput {
    min-height: 80px;
    font-size: 0.8125rem;
  }

  .question-actions {
    flex-direction: row;
    align-items: center;
  }

  .clear-btn-small {
    width: 36px;
    height: 36px;
  }

  /* Mobile Answer Container - Full Width */
  .answer-container {
    margin: 0 -1rem;
    border-radius: 0;
    border-left: none;
    border-right: none;
  }

  .answer-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-md);
  }

  .review-card {
    width: 240px;
  }

  .footer-content {
    flex-direction: column;
    gap: var(--spacing-md);
    text-align: center;
  }

  .footer-links {
    justify-content: center;
    gap: var(--spacing-md);
  }

  .developer-credit {
    text-align: center;
  }

  .modal-content {
    padding: var(--spacing-lg);
    margin: var(--spacing-md);
  }

  .premium-features {
    font-size: 0.875rem;
  }

  .toast {
    right: var(--spacing-sm);
    left: var(--spacing-sm);
    max-width: none;
  }

  .dropdown-menu {
    min-width: 260px;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 16px;
  }

  .header {
    height: 56px;
  }

  .header-content {
    height: 56px;
  }

  .logo-text h1 {
    font-size: 1rem;
  }

  .control-btn {
    width: 32px;
    height: 32px;
  }

  .user-avatar {
    width: 28px;
    height: 28px;
  }

  .free-questions-counter {
    font-size: 0.75rem;
    padding: var(--spacing-xs) 0;
  }

  .subjects-grid {
    padding: var(--spacing-xs);
  }

  .subject-btn {
    min-width: 60px;
    padding: var(--spacing-xs);
  }

  .subject-btn i {
    font-size: 1rem;
  }

  .subject-btn span {
    font-size: 0.625rem;
  }

  .question-container {
    padding: var(--spacing-md);
  }

  .question-header h2 {
    font-size: 1rem;
  }

  .image-upload-btn {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.75rem;
  }

  #questionInput {
    min-height: 70px;
    padding: var(--spacing-sm);
    font-size: 0.75rem;
  }

  .clear-btn-small {
    width: 32px;
    height: 32px;
  }

  .submit-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.75rem;
  }

  .answer-container {
    padding: var(--spacing-md);
  }

  .answer-content {
    font-size: 0.75rem;
  }

  .history-item {
    padding: var(--spacing-sm);
  }

  .review-card {
    width: 200px;
    padding: var(--spacing-sm);
  }

  .footer-container {
    padding: var(--spacing-md) var(--spacing-sm) var(--spacing-sm);
  }

  .footer-links {
    gap: var(--spacing-sm);
  }

  .footer-links a {
    font-size: 0.75rem;
  }

  .footer-links i {
    font-size: 0.75rem;
  }

  .dropdown-menu {
    min-width: 240px;
  }
}

/* Animations */
.fade-in {
  animation: fadeIn 0.3s ease-in;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

@media (prefers-contrast: high) {
  :root {
    --border: #000000;
    --text-secondary: #000000;
  }

  [data-theme="dark"] {
    --border: #ffffff;
    --text-secondary: #ffffff;
  }
}
