:root {
  --fg: #111;
  --muted: #555;
  --line: #ddd;
  --accent: #0b5fff;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--fg);
  background: #f6f7f9;
}
.btp-header, .btp-footer, .btp-main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 16px;
}
.btp-header { display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.btp-header nav { display: flex; gap: 12px; flex-wrap: wrap; }
.btp-logo { font-weight: 700; color: var(--fg); text-decoration: none; }
.btp-trust, .btp-note, .btp-hint { color: var(--muted); }
.btp-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; align-items: start; }
.btp-form fieldset { border: 1px solid var(--line); border-radius: 8px; margin: 0 0 12px; padding: 12px; background: #fff; }
.btp-form label { display: block; font-size: 14px; margin: 8px 0; }
.btp-form input, .btp-form textarea {
  width: 100%;
  font-size: 16px;
  padding: 12px;
  border: 1px solid #ccc;
  border-radius: 6px;
  min-height: 44px;
}
.btp-item { display: grid; grid-template-columns: 1fr 72px 96px 40px; gap: 8px; margin-bottom: 8px; }
.btp-primary, .btp-secondary {
  font-size: 16px;
  min-height: 48px;
  padding: 12px 16px;
  border-radius: 8px;
  border: 0;
  cursor: pointer;
}
.btp-primary { background: var(--accent); color: #fff; width: 100%; }
.btp-secondary { background: #eef; color: var(--fg); }
.btp-error { color: #b00020; }
.btp-preview {
  background: #fff;
  border: 1px solid var(--line);
  padding: 16px;
  min-height: 240px;
}
.btp-preview table { width: 100%; border-collapse: collapse; }
.btp-preview td, .btp-preview th { border-bottom: 1px solid var(--line); padding: 6px; text-align: left; }
.btp-preview .right { text-align: right; }
@media (max-width: 800px) {
  .btp-grid { grid-template-columns: 1fr; }
  .btp-item { grid-template-columns: 1fr; }
}