* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #f5f7fb;
  color: #1f2937;
}
a { color: #2563eb; text-decoration: none; }
.layout { display: flex; min-height: 100vh; }
.sidebar {
  width: 240px;
  background: #111827;
  color: #fff;
  position: sticky;
  top: 0;
  align-self: flex-start;
  padding: 20px 16px;
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.sidebar-header {
  flex: 0 0 auto;
}
.sidebar h2 {
  font-size: 18px;
  margin: 0 0 20px;
}
.sidebar-menu {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior-y: contain;
  padding-right: 4px;
  scrollbar-width: thin;
  scrollbar-color: rgba(148, 163, 184, 0.5) transparent;
}
.sidebar-menu::-webkit-scrollbar {
  width: 8px;
}
.sidebar-menu::-webkit-scrollbar-track {
  background: transparent;
}
.sidebar-menu::-webkit-scrollbar-thumb {
  background: rgba(148, 163, 184, 0.45);
  border-radius: 999px;
  border: 2px solid transparent;
  background-clip: padding-box;
}
.sidebar-menu::-webkit-scrollbar-thumb:hover {
  background: rgba(148, 163, 184, 0.7);
  background-clip: padding-box;
}
.nav-group {
  margin-bottom: 18px;
}
.nav-group-title {
  color: #9ca3af;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0 0 8px;
  padding: 0 12px;
}
.nav-link {
  display: block;
  color: #d1d5db;
  padding: 9px 12px 9px 20px;
  border-radius: 8px;
  margin-bottom: 6px;
}
.nav-link:hover { background: #1f2937; color: #fff; }
.nav-link.active {
  background: #2563eb;
  color: #fff;
  font-weight: 600;
}
.nav-group-bottom {
  flex: 0 0 auto;
  margin-top: 8px;
  padding-top: 12px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}
.content { flex: 1; padding: 24px; }
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}
.card {
  background: #fff;
  border-radius: 12px;
  padding: 18px;
  box-shadow: 0 4px 16px rgba(15, 23, 42, 0.06);
  margin-bottom: 20px;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
}
.stat .num { font-size: 28px; font-weight: 700; }
.stat .label { color: #6b7280; font-size: 13px; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}
.table-wrap {
  overflow-x: auto;
}
th, td {
  border-bottom: 1px solid #e5e7eb;
  text-align: left;
  padding: 10px 8px;
  vertical-align: top;
}
th {
  background: #f9fafb;
  color: #374151;
  position: sticky;
  top: 0;
  z-index: 2;
  box-shadow: 0 1px 0 #e5e7eb;
}
form.inline-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
}
.form-span-2 {
  grid-column: span 2;
}
label {
  display: block;
  font-size: 13px;
  color: #4b5563;
  margin-bottom: 6px;
}
input, select, textarea, button {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  font: inherit;
}
.code-input {
  text-transform: uppercase;
}
.field-note {
  margin-top: 6px;
  font-size: 12px;
  color: #6b7280;
  line-height: 1.5;
}
textarea { min-height: 90px; resize: vertical; }
button, .btn {
  background: #2563eb;
  color: #fff;
  border: none;
  cursor: pointer;
}
button:hover, .btn:hover { background: #1d4ed8; }
.flash-wrap { margin-bottom: 16px; }
.flash {
  padding: 12px 14px;
  border-radius: 8px;
  margin-bottom: 10px;
}
.flash-success { background: #dcfce7; color: #166534; }
.flash-error { background: #fee2e2; color: #991b1b; }
.login-shell {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}
.login-card {
  width: 100%;
  max-width: 420px;
}
.muted { color: #6b7280; font-size: 13px; }
.section-title { margin: 0 0 14px; }
.search-row {
  display: flex;
  gap: 10px;
  align-items: center;
}
.search-row input {
  flex: 1 1 auto;
  min-width: 0;
}
.search-row button,
.search-row .btn {
  width: 120px;
  min-width: 120px;
  flex: 0 0 120px;
}
@media (max-width: 640px) {
  .search-row {
    flex-direction: column;
    align-items: stretch;
  }
  .form-span-2 {
    grid-column: auto;
  }
  .search-row button,
  .search-row .btn {
    width: 100%;
    min-width: 0;
    flex: 1 1 auto;
  }
}
code {
  background: #eef2ff;
  color: #3730a3;
  padding: 2px 6px;
  border-radius: 6px;
}