:root {
  color-scheme: light;
  --primary: #111827;
  --primary-hover: #000000;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #e5e7eb;
  --bg: #f6f7f9;
  --surface: #ffffff;
  --soft: #f9fafb;
  --danger: #dc2626;
  --radius: 8px;
  font-family: "Microsoft YaHei UI", "Segoe UI", system-ui, sans-serif;
}

* { box-sizing: border-box; }
body { min-height: 100vh; margin: 0; color: var(--text); background: var(--bg); }
button, input, textarea { font: inherit; }
button { cursor: pointer; }
[hidden] { display: none !important; }
.buyer-shell { width: min(760px, calc(100% - 32px)); margin: 0 auto; padding: 48px 0; }
.hero { margin-bottom: 18px; }
.eyebrow { margin: 0 0 6px; color: var(--muted); font-size: 12px; font-weight: 800; text-transform: uppercase; }
h1, h2, p { margin-top: 0; letter-spacing: 0; }
h1 { font-size: 34px; margin-bottom: 10px; }
h2 { margin-bottom: 0; }
.subcopy, .note { color: var(--muted); line-height: 1.7; }
.note.is-error { color: var(--danger); }
.panel { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); padding: 20px; margin-bottom: 14px; }
.panel-row { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; margin-bottom: 16px; }
.field { display: grid; gap: 8px; margin-bottom: 14px; }
.field span { color: var(--muted); font-size: 14px; font-weight: 800; }
.field input, textarea { width: 100%; border: 1px solid var(--border); border-radius: var(--radius); color: var(--text); background: #fff; outline: none; }
.field input { min-height: 44px; padding: 0 12px; font-family: Consolas, monospace; }
textarea { min-height: 260px; resize: vertical; padding: 12px; line-height: 1.55; font-family: Consolas, "Microsoft YaHei UI", monospace; }
.field input:focus, textarea:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(17, 24, 39, .08); }
.primary-button, .secondary-button, .tab { min-height: 42px; border-radius: var(--radius); padding: 0 14px; font-weight: 800; }
.primary-button { border: 1px solid var(--primary); color: #fff; background: var(--primary); }
.primary-button:hover { background: var(--primary-hover); }
.secondary-button, .tab { border: 1px solid var(--border); color: var(--text); background: #fff; }
.wide-button { width: 100%; }
.status-chip { display: inline-flex; align-items: center; min-height: 32px; border: 1px solid var(--border); border-radius: var(--radius); padding: 0 10px; color: var(--muted); font-weight: 800; }
.tabs { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin-bottom: 12px; }
.tab.is-active { color: #fff; border-color: var(--primary); background: var(--primary); }
.actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 14px; }
button:disabled { cursor: not-allowed; opacity: .55; }