:root {
  --ink: #1a2332;
  --muted: #5b6675;
  --line: #d8dee7;
  --accent: #0b5cad;
  --bg: #f6f8fb;
  --panel: #ffffff;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--ink);
  background: var(--bg);
}

.topbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 1.25rem;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}

.brand { font-weight: 700; letter-spacing: 0.02em; }

.session { color: var(--muted); }

.nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  margin-left: auto;
}

.nav a { color: var(--accent); text-decoration: none; }
.nav a:hover { text-decoration: underline; }

.inline { display: inline; margin: 0; }

.linklike {
  background: none;
  border: none;
  color: var(--accent);
  cursor: pointer;
  padding: 0;
  font: inherit;
}
.linklike:hover { text-decoration: underline; }

.content {
  max-width: 52rem;
  margin: 2rem auto;
  padding: 0 1.25rem;
}

h1 { font-size: 1.5rem; }
h2 { font-size: 1.15rem; margin-top: 2rem; }

.muted { color: var(--muted); }
.error { color: #b00020; }

.stack { display: grid; gap: 0.75rem; max-width: 24rem; }

form p, form div { margin: 0.5rem 0; }

button {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  cursor: pointer;
  font: inherit;
}