:root {
  --bg: #f4f6f9;
  --panel: #ffffff;
  --border: #e2e8f0;
  --text: #1e293b;
  --muted: #64748b;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --ok: #059669;
  --err: #dc2626;
  --stat-bg: #f8fafc;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  padding: 2rem 1rem;
}
.wrap { max-width: 720px; margin: 0 auto; }
h1 { font-size: 1.35rem; font-weight: 600; margin: 0 0 0.25rem; }
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem 1.35rem;
  margin-bottom: 1rem;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.06);
}
label { display: block; font-size: 0.8rem; color: var(--muted); margin-bottom: 0.35rem; }
.hint {
  margin: 0 0 0.5rem;
  font-size: 0.78rem;
  color: var(--muted);
  line-height: 1.35;
}
.row { display: flex; gap: 0.6rem; flex-wrap: wrap; align-items: stretch; }
input[type="text"] {
  flex: 1;
  min-width: 200px;
  padding: 0.65rem 0.85rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  font-size: 1rem;
}
input[type="password"],
input[type="number"] {
  width: 100%;
  padding: 0.65rem 0.85rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  font-size: 1rem;
}
input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}
button {
  padding: 0.65rem 1.2rem;
  border-radius: 8px;
  border: none;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  font-size: 0.95rem;
}
button:disabled { opacity: 0.55; cursor: not-allowed; }
button:hover:not(:disabled) { background: var(--accent-hover); }
.meta {
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 0.75rem;
}
.meta span.ok { color: var(--ok); }
.meta span.bad { color: var(--err); }
.empty { color: var(--muted); font-size: 0.9rem; }
#upstreamBanner {
  font-size: 1rem;
  color: var(--text);
  margin: 0.15rem 0 0.35rem;
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.85rem;
  margin-top: 0.35rem;
}
@media (max-width: 520px) {
  .stats-grid { grid-template-columns: 1fr; }
}
.stat {
  background: var(--stat-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.1rem;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.stat:hover {
  border-color: #cbd5e1;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
}
.stat-label {
  font-size: 0.78rem;
  color: var(--muted);
  letter-spacing: 0.02em;
}
.stat-value {
  font-size: 1.55rem;
  font-weight: 700;
  margin-top: 0.35rem;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.03em;
  color: var(--text);
}
.hidden { display: none !important; }
.form-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.85rem;
  margin-top: 1rem;
}
@media (max-width: 520px) {
  .form-grid { grid-template-columns: 1fr; }
}
.form-field label {
  margin-bottom: 0.35rem;
}
.card > input[type="text"] {
  width: 100%;
}
.btn-secondary {
  background: #fff;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover:not(:disabled) {
  background: var(--stat-bg);
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }