:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #1f2328;
  --muted: #656d76;
  --accent: #2563eb;
  --error: #c62828;
  --border: #d8dee4;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --card: #161b22;
    --text: #e6edf3;
    --muted: #8d96a0;
    --accent: #4c8dff;
    --error: #ff6b6b;
    --border: #30363d;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

main {
  max-width: 640px;
  margin: 0 auto;
  padding: 32px 16px;
}

h1 { margin: 0; }
.visits { color: var(--muted); }
#visits { color: var(--accent); font-weight: 700; }

form, #messages li {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
}

input, textarea {
  width: 100%;
  margin-bottom: 8px;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
}

.form-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--muted);
}

button {
  padding: 8px 20px;
  border: 0;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  cursor: pointer;
}

button:disabled { opacity: 0.6; cursor: not-allowed; }

#messages { list-style: none; padding: 0; }
#messages li { margin-bottom: 12px; }
#messages p { margin: 8px 0 0; white-space: pre-wrap; word-break: break-word; }

.meta { display: flex; justify-content: space-between; color: var(--muted); font-size: 0.9em; }
.meta strong { color: var(--text); }

.error { color: var(--error); min-height: 1em; margin: 8px 0 0; }

#load-more { display: block; margin: 0 auto; }