:root {
  --bg: #0f0f0f;
  --surface: #1a1a1a;
  --surface-elevated: #252525;
  --surface-hover: #2a2a2a;
  --primary: #6366f1;
  --primary-hover: #818cf8;
  --primary-dim: rgba(99, 102, 241, 0.15);
  --accent: #22d3ee;
  --accent-dim: rgba(34, 211, 238, 0.15);
  --text: #f5f5f5;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --border: #333333;
  --border-light: #404040;
  --danger: #ef4444;
  --danger-hover: #f87171;
  --success: #22c55e;
  --warning: #f59e0b;
  
  --font: 'DM Sans', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  
  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;
  
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
  
  --transition: 200ms ease;
  --sidebar-width: 280px;
  --list-width: 380px;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

/* ==================== LOGIN PAGE ==================== */

.login-page {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: 
    radial-gradient(ellipse at 20% 0%, rgba(99, 102, 241, 0.12) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 100%, rgba(34, 211, 238, 0.08) 0%, transparent 50%),
    var(--bg);
}

.login-container {
  width: 100%;
  max-width: 420px;
  padding: 20px;
}

.login-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 48px 40px;
  box-shadow: var(--shadow-lg);
  animation: fadeIn 400ms ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.login-logo {
  display: flex;
  justify-content: center;
  margin-bottom: 24px;
  color: var(--primary);
}

.login-title {
  font-size: 28px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 8px;
  background: linear-gradient(135deg, var(--text) 0%, var(--primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.login-subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 15px;
  margin-bottom: 32px;
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea {
  background: var(--surface-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  font-family: var(--font);
  font-size: 15px;
  color: var(--text);
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-dim);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--text-muted);
}

.error-message {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid var(--danger);
  color: var(--danger);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  display: none;
  animation: shake 400ms ease;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-8px); }
  40%, 80% { transform: translateX(8px); }
}

.error-message.show {
  display: block;
}

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  font-family: var(--font);
  font-size: 14px;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
  background: var(--surface-elevated);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--surface-hover);
  border-color: var(--border-light);
}

.btn-danger {
  background: rgba(239, 68, 68, 0.1);
  color: var(--danger);
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.btn-danger:hover {
  background: var(--danger);
  color: white;
}

.btn-icon {
  padding: 10px;
  background: transparent;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
}

.btn-icon:hover {
  background: var(--surface-elevated);
  color: var(--text);
}

.btn-full {
  width: 100%;
  padding: 16px;
  font-size: 15px;
}

.btn-compose {
  width: 100%;
  margin: 20px 0;
  padding: 16px;
  background: linear-gradient(135deg, var(--primary) 0%, #8b5cf6 100%);
  color: white;
  font-size: 15px;
}

.btn-compose:hover {
  box-shadow: 0 4px 20px rgba(99, 102, 241, 0.5);
  transform: translateY(-2px);
}

/* Loading spinner */

.btn-loader {
  display: none;
  width: 18px;
  height: 18px;
  border: 2px solid transparent;
  border-top-color: currentColor;
  border-radius: 50%;
  animation: spin 600ms linear infinite;
}

.btn.loading .btn-text {
  display: none;
}

.btn.loading .btn-loader {
  display: block;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.login-hint {
  text-align: center;
  margin-top: 24px;
  font-size: 13px;
  color: var(--text-muted);
}

/* ==================== DASHBOARD ==================== */

.dashboard {
  height: 100vh;
  overflow: hidden;
}

.app-layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) var(--list-width) 1fr;
  height: 100%;
}

/* Sidebar */

.sidebar {
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sidebar-header {
  padding: 20px;
  border-bottom: 1px solid var(--border);
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
}

.folder-list {
  flex: 1;
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.folder-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-family: var(--font);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
  width: 100%;
}

.folder-item:hover {
  background: var(--surface-elevated);
  color: var(--text);
}

.folder-item.active {
  background: var(--primary-dim);
  color: var(--primary);
}

.folder-item .badge {
  margin-left: auto;
  background: var(--primary);
  color: white;
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 10px;
}

.sidebar-footer {
  padding: 16px;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-info {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 16px;
}

.user-details {
  display: flex;
  flex-direction: column;
}

.user-name {
  font-size: 14px;
  font-weight: 600;
}

.user-email {
  font-size: 12px;
  color: var(--text-muted);
}

/* Email List Panel */

.email-list-panel {
  background: var(--bg);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.panel-header {
  padding: 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.panel-title {
  font-size: 18px;
  font-weight: 600;
}

.btn-refresh {
  color: var(--text-muted);
}

.btn-refresh:hover {
  color: var(--primary);
}

.email-list {
  flex: 1;
  overflow-y: auto;
}

.loading-state,
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--text-muted);
  gap: 16px;
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 800ms linear infinite;
}

.email-item {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.email-item:hover {
  background: var(--surface);
}

.email-item.selected {
  background: var(--primary-dim);
  border-left: 3px solid var(--primary);
}

.email-item.unread {
  background: rgba(99, 102, 241, 0.05);
}

.email-item.unread .email-sender {
  font-weight: 700;
  color: var(--text);
}

.email-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.email-sender {
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.email-date {
  font-size: 12px;
  color: var(--text-muted);
  white-space: nowrap;
}

.email-subject-preview {
  font-size: 13px;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Reading Pane */

.reading-pane {
  background: var(--surface);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.welcome-state {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  gap: 16px;
}

.welcome-state h2 {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-secondary);
}

.welcome-state p {
  font-size: 14px;
}

.email-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.email-header {
  padding: 24px;
  border-bottom: 1px solid var(--border);
}

.email-meta {
  margin-bottom: 16px;
}

.meta-row {
  display: flex;
  gap: 12px;
  font-size: 14px;
  margin-bottom: 8px;
}

.meta-label {
  color: var(--text-muted);
  min-width: 50px;
}

.meta-value {
  color: var(--text);
  word-break: break-all;
}

.email-actions {
  display: flex;
  gap: 8px;
}

.email-actions .btn {
  padding: 10px 16px;
  font-size: 13px;
}

.email-subject {
  padding: 20px 24px;
  font-size: 20px;
  font-weight: 600;
  border-bottom: 1px solid var(--border);
}

.email-body {
  flex: 1;
  padding: 24px;
  overflow-y: auto;
  font-size: 15px;
  line-height: 1.7;
  white-space: pre-wrap;
  word-wrap: break-word;
}

/* Modal */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
}

.modal-overlay.show {
  opacity: 1;
  visibility: visible;
}

.modal {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 600px;
  max-height: 90vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transform: scale(0.95);
  transition: var(--transition);
}

.modal-overlay.show .modal {
  transform: scale(1);
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-header h3 {
  font-size: 18px;
  font-weight: 600;
}

.compose-form {
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.compose-form .form-group textarea {
  resize: vertical;
  min-height: 200px;
  font-family: var(--font);
  line-height: 1.6;
}

.modal-actions {
  display: flex;
  gap: 12px;
  justify-content: flex-end;
  padding-top: 8px;
}

/* Toast notifications */

.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 2000;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  background: var(--surface-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 20px;
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 12px;
  box-shadow: var(--shadow-lg);
  animation: slideIn 300ms ease;
}

.toast.success {
  border-color: var(--success);
}

.toast.error {
  border-color: var(--danger);
}

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

/* Scrollbar */

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--border-light);
}

/* Responsive */

@media (max-width: 1024px) {
  .app-layout {
    grid-template-columns: 220px 300px 1fr;
  }
}

/* AI Features */
.ai-summary {
  background: var(--surface-elevated);
  border-radius: var(--radius);
  padding: 16px;
  margin: 16px;
  border-left: 3px solid var(--accent);
}

.ai-badge {
  display: inline-block;
  background: var(--accent-dim);
  color: var(--accent);
  font-size: 11px;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: 4px;
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.ai-summary p {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.6;
  margin: 0;
}

.btn.loading {
  opacity: 0.7;
  pointer-events: none;
}

.btn.loading::after {
  content: '';
  display: inline-block;
  width: 12px;
  height: 12px;
  border: 2px solid transparent;
  border-top-color: currentColor;
  border-radius: 50%;
  margin-left: 6px;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

@media (max-width: 768px) {
  .app-layout {
    grid-template-columns: 1fr;
  }
  
  .sidebar {
    display: none;
  }
  
  .email-list-panel {
    display: none;
  }
  
  .reading-pane {
    width: 100%;
  }
}