:root {
  --bg: #f4f5f7;
  --surface: #ffffff;
  --ink: #121417;
  --muted: #5c6570;
  --line: #e4e6ea;
  --line-strong: #d5d8de;
  --accent: #0f6b63;
  --accent-hover: #0c574f;
  --accent-soft: #e7f3f1;
  --danger: #b42318;
  --sans: "DM Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

html, body { margin: 0; min-height: 100%; }

body.app {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.45;
  -webkit-font-smoothing: antialiased;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }

.app-header {
  height: 56px;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 18px;
  gap: 16px;
  flex-shrink: 0;
}

.app-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 650;
  letter-spacing: -0.02em;
}

.app-brand small {
  display: block;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.app-nav { display: flex; gap: 8px; align-items: center; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 34px;
  padding: 0 12px;
  border-radius: 8px;
  border: 1px solid transparent;
  background: var(--ink);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}

.btn:hover { background: var(--accent); }
.btn-ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--line-strong);
}
.btn-ghost:hover { background: var(--bg); color: var(--ink); }

.app-main { flex: 1; }

.app-footer {
  border-top: 1px solid var(--line);
  padding: 12px 18px;
  color: var(--muted);
  font-size: 12px;
  background: var(--surface);
}

.note {
  background: var(--accent-soft);
  color: var(--accent-hover);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 13px;
}

.err {
  color: var(--danger);
  font-size: 13px;
}

pre, code, .mono {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}