:root {
  --bg-primary: #0f1923;
  --bg-secondary: #1a2733;
  --bg-tertiary: #243447;
  --bg-card: #1e2d3d;
  --text-primary: #e8edf2;
  --text-secondary: #8899aa;
  --text-muted: #5a6d7e;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --accent-dim: rgba(59, 130, 246, 0.15);
  --danger: #ef4444;
  --success: #22c55e;
  --warning: #f59e0b;
  --border: #2a3a4a;
  --sidebar-width: 240px;
  --topbar-height: 56px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Inter', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }

/* Layout */
.app-layout {
  display: flex;
  min-height: 100vh;
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 100;
  transition: transform 0.3s;
}

.sidebar-brand {
  padding: 20px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 12px;
}

.sidebar-brand svg { flex-shrink: 0; }

.sidebar-brand h1 {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.5px;
  color: var(--text-primary);
}

.sidebar-brand span {
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.sidebar-nav {
  flex: 1;
  padding: 12px 0;
  overflow-y: auto;
}

.nav-section {
  padding: 8px 20px 4px;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  font-weight: 600;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 20px;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
  transition: all 0.15s;
  border-left: 3px solid transparent;
}

.nav-link:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.nav-link.active {
  color: var(--accent);
  background: var(--accent-dim);
  border-left-color: var(--accent);
}

.nav-link svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

/* Main content */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Top bar */
.topbar {
  height: var(--topbar-height);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  position: sticky;
  top: 0;
  z-index: 50;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.topbar-title {
  font-size: 16px;
  font-weight: 600;
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  color: var(--text-secondary);
}

.user-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 13px;
  color: white;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  border: none;
  cursor: pointer;
  transition: all 0.15s;
  text-decoration: none;
}

.btn-primary { background: var(--accent); color: white; }
.btn-primary:hover { background: var(--accent-hover); color: white; }
.btn-danger { background: var(--danger); color: white; }
.btn-danger:hover { background: #dc2626; color: white; }
.btn-outline {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}
.btn-outline:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}
.btn-sm { padding: 5px 10px; font-size: 12px; }
.btn-ghost { background: transparent; color: var(--text-secondary); }
.btn-ghost:hover { color: var(--text-primary); background: var(--bg-tertiary); }

/* Content area */
.content {
  flex: 1;
  padding: 24px;
}

.page-header {
  margin-bottom: 24px;
}

.page-header h2 {
  font-size: 22px;
  font-weight: 700;
}

.page-header p {
  color: var(--text-secondary);
  font-size: 14px;
  margin-top: 4px;
}

/* Cards */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px;
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.card-header h3 {
  font-size: 15px;
  font-weight: 600;
}

/* Stats grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.stat-icon {
  width: 42px;
  height: 42px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.stat-icon.blue { background: rgba(59,130,246,0.15); color: var(--accent); }
.stat-icon.green { background: rgba(34,197,94,0.15); color: var(--success); }
.stat-icon.amber { background: rgba(245,158,11,0.15); color: var(--warning); }
.stat-icon.red { background: rgba(239,68,68,0.15); color: var(--danger); }

.stat-info h4 {
  font-size: 24px;
  font-weight: 700;
  line-height: 1;
}

.stat-info p {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 4px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* Table */
.table-wrap {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  padding: 10px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
}

th {
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 11px;
  letter-spacing: 0.5px;
}

td { color: var(--text-secondary); }

tr:hover td { background: rgba(255,255,255,0.02); }

.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
}

.badge-admin { background: rgba(59,130,246,0.2); color: var(--accent); }
.badge-member { background: rgba(34,197,94,0.2); color: var(--success); }

/* Forms */
.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.form-control {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-primary);
  font-size: 14px;
  transition: border-color 0.15s;
}

.form-control:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-dim);
}

select.form-control {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%238899aa' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
}

.alert {
  padding: 12px 16px;
  border-radius: 6px;
  font-size: 13px;
  margin-bottom: 16px;
}

.alert-error { background: rgba(239,68,68,0.15); color: #fca5a5; border: 1px solid rgba(239,68,68,0.3); }
.alert-success { background: rgba(34,197,94,0.15); color: #86efac; border: 1px solid rgba(34,197,94,0.3); }

/* Chat */
.chat-container {
  display: flex;
  flex-direction: column;
  height: calc(100vh - var(--topbar-height) - 48px);
}

.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.chat-message {
  max-width: 80%;
  padding: 12px 16px;
  border-radius: 12px;
  font-size: 14px;
  line-height: 1.5;
  white-space: pre-wrap;
  word-wrap: break-word;
}

.chat-message.user {
  align-self: flex-end;
  background: var(--accent);
  color: white;
  border-bottom-right-radius: 4px;
}

.chat-message.assistant {
  align-self: flex-start;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border-bottom-left-radius: 4px;
}

.chat-message.system {
  align-self: center;
  background: transparent;
  color: var(--text-muted);
  font-size: 12px;
  padding: 4px 8px;
  white-space: pre-line;
}

.chat-message.thinking {
  color: var(--text-muted);
  font-style: italic;
  animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 0.5; }
  50% { opacity: 1; }
}

.chat-input-area {
  padding: 16px;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 10px;
}

.chat-input-area input {
  flex: 1;
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 14px;
}

.chat-input-area input:focus {
  outline: none;
  border-color: var(--accent);
}

.chat-input-area button {
  padding: 12px 20px;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s;
}

.chat-input-area button:hover { background: var(--accent-hover); }
.chat-input-area button:disabled { opacity: 0.5; cursor: not-allowed; }

.chat-status {
  text-align: center;
  padding: 4px;
  font-size: 11px;
  color: var(--text-muted);
}

.chat-status.connected { color: var(--success); }
.chat-status.error { color: var(--danger); }

/* Login page */
.login-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-primary);
}

.login-box {
  width: 100%;
  max-width: 400px;
  padding: 40px;
}

.login-box .brand {
  text-align: center;
  margin-bottom: 32px;
}

.login-box .brand h1 {
  font-size: 24px;
  font-weight: 700;
  margin-top: 12px;
}

.login-box .brand p {
  color: var(--text-muted);
  font-size: 13px;
  margin-top: 4px;
}

/* Placeholder page styling */
.placeholder-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 300px;
  text-align: center;
  color: var(--text-muted);
}

.placeholder-content svg { margin-bottom: 16px; opacity: 0.5; }
.placeholder-content h3 { font-size: 18px; margin-bottom: 8px; color: var(--text-secondary); }
.placeholder-content p { font-size: 14px; }

/* File size display */
.file-size {
  color: var(--text-muted);
  font-size: 12px;
}

/* Responsive */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  padding: 4px;
}

@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .main-content {
    margin-left: 0;
  }
  .menu-toggle {
    display: block;
  }
  .stats-grid {
    grid-template-columns: 1fr;
  }
  .chat-message {
    max-width: 95%;
  }
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* Modal */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: 200;
  align-items: center;
  justify-content: center;
}

.modal-overlay.active { display: flex; }

.modal {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px;
  width: 90%;
  max-width: 440px;
}

.modal h3 { margin-bottom: 16px; }