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

:root {
  --primary: #3b82f6;
  --primary-dark: #2563eb;
  --success: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  --bg: #f5f7fa;
  --card: #ffffff;
  --border: #e5e7eb;
  --text: #1f2937;
  --text-secondary: #6b7280;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-lg: 0 4px 12px rgba(0,0,0,0.15);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
    'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  font-size: 14px;
  line-height: 1.5;
}

.screen { min-height: 100vh; }
.hidden { display: none !important; }

/* ─── Login ─── */
#login-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.login-box {
  background: var(--card);
  padding: 2.5rem;
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  width: 90%;
  max-width: 400px;
}

.login-box h1 { font-size: 1.5rem; margin-bottom: 0.5rem; }
.login-box .subtitle { color: var(--text-secondary); margin-bottom: 1.5rem; }
.login-box input {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 1rem;
  margin-bottom: 1rem;
  transition: border-color 0.2s;
}
.login-box input:focus { outline: none; border-color: var(--primary); }
.login-box button { width: 100%; padding: 0.75rem; font-size: 1rem; }

/* ─── Main Layout ─── */
#main-screen {
  display: grid;
  grid-template-columns: 240px 1fr;
  grid-template-rows: 56px 1fr;
  grid-template-areas: "header header" "sidebar content";
  height: 100vh;
}

header {
  grid-area: header;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 1.5rem;
}
.header-content { display: flex; align-items: center; justify-content: space-between; width: 100%; }
.header-content h1 { font-size: 1.1rem; }
.header-actions { display: flex; align-items: center; gap: 1rem; }
.breadcrumb { color: var(--text-secondary); font-size: 0.9rem; }

/* ─── Sidebar ─── */
.sidebar {
  grid-area: sidebar;
  background: var(--card);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 1rem 0;
  display: flex;
  flex-direction: column;
}
.sidebar-section { margin-bottom: 1.5rem; }
.sidebar-bottom { margin-top: auto; margin-bottom: 0; }

.sidebar-title {
  padding: 0 1rem 0.5rem;
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-list { list-style: none; }
.nav-item {
  padding: 0.6rem 1rem;
  cursor: pointer;
  border-left: 3px solid transparent;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: background 0.15s;
  font-size: 0.9rem;
}
.nav-item:hover { background: var(--bg); }
.nav-item.active {
  background: #eff6ff;
  border-left-color: var(--primary);
  color: var(--primary-dark);
  font-weight: 500;
}
.nav-icon { flex-shrink: 0; }

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}
.status-dot.ready { background: var(--success); }
.status-dot.not-ready { background: var(--danger); }

.content {
  grid-area: content;
  overflow-y: auto;
  padding: 1.5rem;
}

/* ─── Buttons ─── */
.btn {
  padding: 0.5rem 1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--card);
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.15s;
  color: var(--text);
}
.btn:hover { background: var(--bg); }

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

.btn-danger {
  background: var(--danger);
  color: white;
  border-color: var(--danger);
}
.btn-danger:hover { background: #dc2626; }

.btn-ghost { background: transparent; border: none; color: var(--text-secondary); }
.btn-ghost:hover { color: var(--text); background: var(--bg); }

.btn-sm { padding: 0.35rem 0.75rem; font-size: 0.85rem; }

.btn-icon {
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0.2rem 0.4rem;
  font-size: 1rem;
  color: var(--text-secondary);
  border-radius: 4px;
}
.btn-icon:hover { background: var(--bg); color: var(--text); }

/* ─── Cards ─── */
.card {
  background: var(--card);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 1.25rem;
  margin-bottom: 1rem;
}
.card-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* ─── Tables ─── */
.table { width: 100%; border-collapse: collapse; }
.table th, .table td {
  padding: 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.table th {
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 0.85rem;
  background: var(--bg);
}
.table tbody tr:hover { background: var(--bg); }

/* ─── Badges ─── */
.badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 500;
}
.badge-success { background: #d1fae5; color: #065f46; }
.badge-danger { background: #fee2e2; color: #991b1b; }
.badge-warning { background: #fef3c7; color: #92400e; }
.badge-info { background: #dbeafe; color: #1e40af; }

/* ─── Status ─── */
.loading, .error {
  padding: 1rem;
  text-align: center;
  color: var(--text-secondary);
}
.error {
  color: var(--danger);
  background: #fee2e2;
  border-radius: 6px;
  margin: 0.5rem 0;
}

/* ─── Stats ─── */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 1.5rem;
}
.stat-card {
  background: var(--card);
  border-radius: 8px;
  padding: 1rem;
  box-shadow: var(--shadow);
}
.stat-label { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 0.25rem; }
.stat-value { font-size: 1.5rem; font-weight: 600; }

/* ─── Empty state ─── */
.empty {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-secondary);
}
.empty-icon { font-size: 3rem; margin-bottom: 0.5rem; }
.empty-hint { margin-top: 1rem; }

/* ─── Modal ─── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
}
.modal {
  background: var(--card);
  border-radius: 8px;
  box-shadow: var(--shadow-lg);
  width: 90%;
  max-width: 520px;
  max-height: 85vh;
  display: flex;
  flex-direction: column;
}
.modal-header {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.modal-header h3 { font-size: 1.05rem; }
.modal-body { padding: 1.25rem; overflow-y: auto; }

/* ─── Forms ─── */
.form-group { margin-bottom: 1rem; }
.form-group label {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}
.form-group input, .form-group select, .form-group textarea {
  width: 100%;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.9rem;
  font-family: inherit;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
}
.form-hint { font-size: 0.8rem; color: var(--text-secondary); margin-top: 0.25rem; }
.form-actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

/* ─── Utilities ─── */
code {
  background: var(--bg);
  padding: 0.15rem 0.4rem;
  border-radius: 3px;
  font-family: 'SF Mono', Menlo, monospace;
  font-size: 0.85em;
}
.text-secondary { color: var(--text-secondary); }
.text-sm { font-size: 0.85rem; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }

@media (max-width: 768px) {
  #main-screen {
    grid-template-columns: 1fr;
    grid-template-areas: "header" "content";
  }
  .sidebar { display: none; }
}