/* css/app.css */

.app-body {
  margin: 0;
  padding: 0;
  overflow: hidden;
}

.app-shell {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

.sidebar {
  width: var(--sidebar-width);
  background: var(--sidebar-bg);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  overflow-y: auto;
  z-index: 100;
  transition: transform var(--transition);
}

.sidebar-header {
  padding: var(--space-6);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.sidebar-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: white;
  font-weight: 700;
  font-size: var(--text-lg);
}
.sidebar-close-btn {
  background: transparent;
  border: none;
  color: var(--sidebar-text);
  cursor: pointer;
  font-size: var(--text-lg);
}

.sidebar-due-card {
  margin: var(--space-6);
  padding: var(--space-6);
  background: rgba(255,255,255,0.05);
  border-radius: var(--radius-md);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  border: 1px solid rgba(255,255,255,0.1);
  transition: var(--transition);
}
.sidebar-due-card.has-due {
  background: rgba(239, 68, 68, 0.1);
  border-color: rgba(239, 68, 68, 0.3);
}
.sidebar-due-card .due-number {
  font-size: var(--text-3xl);
  font-weight: 800;
  color: white;
}
.sidebar-due-card .due-label {
  font-size: var(--text-xs);
  color: var(--sidebar-text);
}
.sidebar-due-card .study-now-btn {
  width: 100%;
}

.sidebar-nav {
  flex: 1;
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  color: var(--sidebar-text);
  text-decoration: none;
  font-size: var(--text-sm);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}
.nav-item:hover {
  background: rgba(255,255,255,0.08);
  color: white;
}
.nav-item.active {
  background: var(--sidebar-active);
  color: white;
  font-weight: 600;
}
.nav-icon {
  font-size: 16px;
  width: 20px;
  text-align: center;
}
.nav-divider {
  height: 1px;
  background: rgba(255,255,255,0.1);
  margin: var(--space-6) 0;
}

.sidebar-footer {
  padding: var(--space-6);
  border-top: 1px solid rgba(255,255,255,0.1);
}
.pro-badge {
  background: linear-gradient(45deg, #F59E0B, #EF4444);
  color: white;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 700;
  text-align: center;
}
.pro-expiry {
  font-size: 10px;
  color: var(--sidebar-text);
  text-align: center;
  margin-top: 4px;
}
.free-usage-bar {
  background: rgba(255,255,255,0.05);
  padding: var(--space-4);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-4);
}
.free-usage-label {
  display: flex;
  justify-content: space-between;
  font-size: var(--text-xs);
  color: var(--sidebar-text);
  margin-bottom: 6px;
}
.usage-track {
  height: 4px;
  background: rgba(255,255,255,0.1);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.usage-fill {
  height: 100%;
  background: var(--color-primary);
  transition: width 0.3s ease;
}

.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.app-topbar {
  height: 64px;
  padding: 0 var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--color-border);
  background: white;
}
.sidebar-toggle-btn {
  background: transparent;
  border: none;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: var(--space-2);
}
.sidebar-toggle-btn span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-text);
  transition: var(--transition);
}
.topbar-title {
  font-size: var(--text-lg);
  font-weight: 700;
  margin: 0;
}
.view-container {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-6);
  background: var(--color-bg);
}

.loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--color-text-secondary);
}
.loading-spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: var(--space-4);
}
@keyframes spin { to { transform: rotate(360deg); } }

@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    transform: translateX(-100%);
  }
  .sidebar.open {
    transform: translateX(0);
    box-shadow: var(--shadow-lg);
  }
  .app-topbar {
    display: flex;
  }
}
@media (min-width: 769px) {
  .app-topbar { display: none; }
  .sidebar-close-btn { display: none; }
}

/* Study View Specifics */
.rating-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
  margin-top: var(--space-6);
}
.rating-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-4);
  border-radius: var(--radius-md);
  border: 2px solid var(--color-border);
  cursor: pointer;
  transition: var(--transition);
  font-size: var(--text-base);
  font-weight: 600;
  background: white;
}
.rating-btn .interval-preview {
  font-size: var(--text-xs);
  font-weight: 400;
  color: var(--color-text-secondary);
  margin-top: 4px;
}
.rating-btn.again { border-color: var(--color-danger); color: var(--color-danger); }
.rating-btn.again:hover { background: var(--color-danger); color: white; }
.rating-btn.hard { border-color: var(--color-warning); color: var(--color-warning); }
.rating-btn.hard:hover { background: var(--color-warning); color: white; }
.rating-btn.good { border-color: var(--color-primary); color: var(--color-primary); }
.rating-btn.good:hover { background: var(--color-primary); color: white; }
.rating-btn.easy { border-color: var(--color-success); color: var(--color-success); }
.rating-btn.easy:hover { background: var(--color-success); color: white; }

@keyframes slideIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Markdown content styles */
.markdown-content h1, .markdown-content h2, .markdown-content h3 { margin-top: 0; }
.markdown-content p { margin-bottom: var(--space-4); line-height: 1.6; }
.markdown-content ul, .markdown-content ol { margin-bottom: var(--space-4); padding-left: var(--space-6); }
.markdown-content li { margin-bottom: var(--space-2); }
/* ... previous content ... */
.markdown-content code { background: var(--color-surface-2); padding: 2px 4px; border-radius: 4px; font-family: var(--font-mono); font-size: var(--text-xs); }

.sidebar-all-caught {
  font-size: 12px;
  color: #10B981;
  font-weight: 600;
  margin-top: 4px;
  text-align: center;
}

.deck-card {
  background: white;
  border: 1.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  cursor: pointer;
  transition: all 200ms ease;
  position: relative;
  overflow: hidden;
}
.deck-card:hover {
  border-color: #93C5FD;
  box-shadow: 0 4px 20px rgba(37,99,235,0.1);
  transform: translateY(-2px);
}
.deck-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--deck-color, #2563EB);
}
.deck-card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}
.deck-icon { font-size: 24px; }
.deck-name { font-size: 16px; font-weight: 700; color: #0F172A; }
.deck-description { font-size: 13px; color: #94A3B8; margin-top: 2px; }
.deck-syllabus {
  font-size: 11px;
  color: #2563EB;
  background: #DBEAFE;
  padding: 2px 8px;
  border-radius: 9999px;
  display: inline-block;
  margin-bottom: 16px;
}
.deck-stats {
  display: flex;
  gap: 16px;
  margin-bottom: 16px;
}
.deck-stat { font-size: 12px; color: #64748B; }
.deck-stat strong { color: #0F172A; }
.deck-actions {
  display: flex;
  gap: 8px;
}
.deck-actions .btn {
  flex: 1;
  justify-content: center;
  font-size: 13px;
}
.deck-due-badge {
  position: absolute;
  top: 16px;
  right: 16px;
  background: #2563EB;
  color: white;
  font-size: 11px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 9999px;
}

.autosave-status {
  font-size: 12px;
  font-weight: 500;
  margin-left: 12px;
  transition: all 200ms;
}
.autosave-status.saving { color: #F59E0B; }
.autosave-status.saved { color: #10B981; }
.autosave-status.error { color: #EF4444; }