:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #1f2933;
  --muted: #6b7280;
  --accent: #2563eb;
  --border: #e5e7eb;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
main { flex: 1; width: 100%; max-width: 1080px; margin: 0 auto; padding: 32px 20px 48px; }
header.site-header {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 18px 20px;
}
.header-inner { max-width: 1080px; margin: 0 auto; display: flex; align-items: baseline; gap: 16px; }
.header-inner h1 { margin: 0; font-size: 22px; }
.header-inner nav a { color: var(--muted); text-decoration: none; margin-left: 16px; font-size: 14px; }
.header-inner nav a:hover { color: var(--accent); }

h2.page-title { margin: 8px 0 20px; font-size: 20px; }
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 16px;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  text-decoration: none;
  color: var(--text);
  transition: box-shadow .15s, transform .15s;
}
.card:hover { box-shadow: 0 4px 14px rgba(0,0,0,.08); transform: translateY(-2px); }
.card .icon { font-size: 26px; }
.card h3 { margin: 10px 0 6px; font-size: 16px; }
.card p { margin: 0; font-size: 13px; color: var(--muted); line-height: 1.5; }

.panel {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 16px;
}
textarea, input[type=text], input[type=number] {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px;
  font-family: ui-monospace, Consolas, monospace;
  font-size: 13px;
  resize: vertical;
}
textarea { min-height: 140px; }
.row { display: flex; gap: 10px; flex-wrap: wrap; margin: 12px 0; align-items: center; }
button.btn {
  background: var(--accent);
  color: #fff;
  border: 0;
  border-radius: 6px;
  padding: 9px 18px;
  font-size: 14px;
  cursor: pointer;
}
button.btn:hover { opacity: .9; }
button.btn.secondary { background: #eef2ff; color: var(--accent); }
.output {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px;
  font-family: ui-monospace, Consolas, monospace;
  font-size: 13px;
  white-space: pre-wrap;
  word-break: break-all;
  min-height: 44px;
}
.output.ok { border-color: #86efac; background: #f0fdf4; }
.output.err { border-color: #fca5a5; background: #fef2f2; color: #b91c1c; }
label.inline { font-size: 13px; color: var(--muted); display: flex; align-items: center; gap: 6px; }
select { padding: 8px; border: 1px solid var(--border); border-radius: 6px; font-size: 14px; }

footer.site-footer {
  border-top: 1px solid var(--border);
  background: var(--card);
  padding: 20px;
  margin-top: auto;
}
.footer-inner { max-width: 1080px; margin: 0 auto; text-align: center; font-size: 13px; color: var(--muted); }
.footer-inner p { margin: 4px 0; }
.footer-inner a { color: var(--muted); text-decoration: none; }
.footer-inner a:hover { color: var(--accent); }

@media (max-width: 640px) {
  .header-inner { flex-direction: column; gap: 6px; }
}