:root {
  --bg: #f5f7fa;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --accent: #2563eb;
  --ok: #16a34a;
  --warn: #d97706;
  --err: #dc2626;
  --border: #e5e7eb;
  --node-bg: #f9fafb;
  --node-hover-bg: #f3f4f6;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

.card {
  width: 100%;
  max-width: 520px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 28px 24px;
  box-shadow: 0 4px 16px rgba(15, 23, 42, 0.06);
}

.title { margin: 0 0 6px; font-size: 20px; }
.subtitle { margin: 0 0 18px; color: var(--muted); font-size: 14px; }

.nodes {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.node {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--node-bg);
  cursor: pointer;
  transition: border-color .15s, background-color .15s, transform .05s;
}
.node:hover { border-color: var(--accent); background: var(--node-hover-bg); }
.node:active { transform: scale(0.995); }
.node.winner { border-color: var(--ok); background: #ecfdf5; }
.node.failed { opacity: .55; cursor: not-allowed; }

.node-name { font-weight: 600; }
.node-host { color: var(--muted); font-size: 12px; margin-top: 2px; }
.node-meta { text-align: right; font-variant-numeric: tabular-nums; font-size: 13px; }
.node-samples { color: var(--muted); font-size: 11px; margin-left: 4px; }
.badge {
  display: inline-block;
  margin-left: 8px;
  padding: 1px 8px;
  font-size: 11px;
  border-radius: 999px;
  background: var(--ok);
  color: #ffffff;
}
.badge.warn { background: var(--warn); color: #ffffff; }
.badge.err  { background: var(--err);  color: #ffffff; }

.footer {
  margin-top: 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 22px;
}
.countdown { color: var(--muted); font-size: 13px; }
.link-btn {
  background: none;
  border: none;
  color: var(--accent);
  cursor: pointer;
  font-size: 13px;
  padding: 0;
}
.link-btn:hover { text-decoration: underline; }

.error { color: var(--err); }