:root {
  color-scheme: light;
  --bg: #f5f7f9;
  --panel: #ffffff;
  --ink: #16202a;
  --muted: #667789;
  --line: #d9e1e8;
  --accent: #136f63;
  --danger: #8f1d2c;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 32px;
  border-bottom: 1px solid var(--line);
  background: #fff;
}
.brand { color: var(--ink); font-weight: 800; text-decoration: none; }
nav { display: flex; gap: 16px; }
nav a { color: var(--muted); text-decoration: none; }
.shell { max-width: 1080px; margin: 40px auto; padding: 0 20px; }
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 28px;
  box-shadow: 0 12px 30px rgba(22, 32, 42, 0.06);
}
.narrow { max-width: 680px; margin: 0 auto; }
.panel-head { margin-bottom: 24px; }
h1 { font-size: 30px; margin: 0 0 10px; letter-spacing: 0; }
h2 { font-size: 18px; margin-top: 28px; }
p { line-height: 1.55; }
.muted { color: var(--muted); }
.form-grid { display: grid; gap: 18px; }
.stacked { display: grid; gap: 14px; margin-top: 18px; }
label { display: grid; gap: 6px; font-weight: 650; }
input, select, textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 11px 12px;
  font: inherit;
  background: #fff;
}
fieldset { border: 1px solid var(--line); border-radius: 6px; padding: 14px; }
button {
  justify-self: start;
  border: 0;
  border-radius: 6px;
  padding: 11px 16px;
  color: white;
  background: var(--accent);
  font-weight: 750;
  cursor: pointer;
}
.danger button { background: var(--danger); }
.messages { display: grid; gap: 10px; margin-bottom: 18px; }
.message { border-radius: 6px; padding: 12px 14px; background: #e9f4f1; border: 1px solid #bee0d8; }
.message.error { background: #fff0f1; border-color: #f2bbc2; }
.errors { color: var(--danger); }
.secret {
  white-space: pre-wrap;
  background: #0e1b22;
  color: #eef8f6;
  border-radius: 8px;
  padding: 20px;
  overflow: auto;
}
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 14px; }
.stats div { border: 1px solid var(--line); border-radius: 8px; padding: 16px; }
.stats strong { display: block; font-size: 28px; }
.stats span { color: var(--muted); }
table { width: 100%; border-collapse: collapse; margin-top: 14px; }
th, td { text-align: left; border-bottom: 1px solid var(--line); padding: 10px 8px; vertical-align: top; }
.inline-form { display: flex; gap: 10px; align-items: center; }
@media (max-width: 720px) {
  .topbar { align-items: flex-start; flex-direction: column; gap: 12px; padding: 16px 20px; }
  nav { flex-wrap: wrap; }
  .shell { margin: 22px auto; }
  .panel { padding: 20px; }
  .inline-form { display: grid; }
}