:root {
  --bg: #f6f7fb;
  --card: #ffffff;
  --border: #e5e8ef;
  --ink: #1a1d29;
  --muted: #6b7280;
  --accent: #4f46e5;
  --accent-2: #7c3aed;
  --green: #16a34a;
  --red: #dc2626;
  --amber: #d97706;
  --radius: 14px;
  --shadow: 0 1px 3px rgba(20, 24, 40, 0.08);
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans Thai', sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.5;
}
#app { min-height: 100vh; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
}
button {
  font-family: inherit;
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--card);
  padding: 10px 16px;
  border-radius: 10px;
  font-size: 14px;
  color: var(--ink);
}
button.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  border: none;
}
button:disabled { opacity: 0.5; cursor: not-allowed; }
input, select, textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-family: inherit;
  font-size: 14px;
}
label { font-size: 13px; color: var(--muted); display: block; margin: 10px 0 4px; }
.row { display: flex; gap: 12px; flex-wrap: wrap; }
.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
}
.badge.A { background: #dcfce7; color: #166534; }
.badge.B { background: #fef9c3; color: #854d0e; }
.badge.C { background: #fee2e2; color: #991b1b; }
.badge.won { background: #dcfce7; color: #166534; }
.badge.lost { background: #fee2e2; color: #991b1b; }
.badge.not_tried { background: #eef2ff; color: #4338ca; }
.error { color: var(--red); font-size: 13px; }
.muted { color: var(--muted); }
.msg-seller { background: var(--accent); color: #fff; align-self: flex-end; border-radius: 16px 16px 4px 16px; }
.msg-customer { background: #fff; align-self: flex-start; border-radius: 16px 16px 16px 4px; border: 1px solid var(--border); }

/* ── UX polish: focus rings, touch targets, transitions ───────────── */
/* Visible focus rings for keyboard nav (a11y) */
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
a { color: inherit; }
a:focus { outline: 2px solid var(--accent); outline-offset: 2px; }

/* Comfortable touch density + consistent transitions */
button { min-height: 44px; transition: transform .15s ease, box-shadow .2s ease, background .2s ease, opacity .2s ease; display: inline-flex; align-items: center; justify-content: center; gap: 6px; }
button:not(:disabled):hover { box-shadow: 0 4px 12px rgba(20,24,40,.1); }
button:not(:disabled):active { transform: scale(.97); }
button.primary:not(:disabled):hover { box-shadow: 0 6px 18px rgba(79,70,229,.35); }
button.soft { background: #f1f3f9; border-color: transparent; color: var(--ink); }
button.soft:not(:disabled):hover { background: #e6eaf3; }
/* Align inline SVG (lucide) icons inside buttons/links */
button svg, .icon-btn svg, .brand svg { vertical-align: -2px; }

input, select, textarea {
  min-height: 44px;
  transition: border-color .15s ease, box-shadow .15s ease;
}
input:focus, select:focus, textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(79,70,229,.15);
}
textarea { min-height: 88px; resize: vertical; }

/* Cards lift on hover (only for interactive/uniform card grids) */
.card.lift { transition: transform .2s ease, box-shadow .25s ease; }
.card.lift:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(20,24,40,.10); }

/* Disabled clarity */
button:disabled { opacity: .5; cursor: not-allowed; box-shadow: none; }

/* Back link button */
.btn-back {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 14px; margin-bottom: 12px;
  background: transparent; border: 1px solid var(--border); border-radius: 10px;
  color: var(--muted); font-size: 13px; text-decoration: none;
}
.btn-back:hover { color: var(--ink); border-color: var(--accent); }

/* Status spinner */
.spinner {
  width: 16px; height: 16px; border-radius: 50%;
  border: 2px solid rgba(255,255,255,.4); border-top-color: #fff;
  animation: spin .7s linear infinite; display: inline-block;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Skeleton loading blocks */
.skeleton {
  border-radius: 8px;
  background: linear-gradient(90deg, #eef0f5 25%, #e2e5ec 37%, #eef0f5 63%);
  background-size: 400% 100%;
  animation: shimmer 1.4s ease infinite;
}
@keyframes shimmer { 0% { background-position: 100% 0; } 100% { background-position: -100% 0; } }

/* Respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}

/* Empty-state block */
.empty-state { text-align: center; padding: 40px 20px; color: var(--muted); }
.empty-state strong { display: block; margin-bottom: 4px; color: var(--ink); }

/* Field helper/error lines under inputs */
.field-error { color: var(--red); font-size: 12px; margin-top: 4px; }

/* Responsive container default */
@media (max-width: 640px) {
  .main { padding: 16px; }
  .row { gap: 10px; }
  .msg-seller, .msg-customer { max-width: 84%; }
  /* Moreminimore convention: centered content when a section collapses to one column */
  .stat-row > .card, .row.stat > .card { flex: 1 1 40%; text-align: center; }
  .stat div { text-align: center; }
}
@media (max-width: 460px) {
  .row.stat, .stat-row, .row.stat-row { justify-content: center; }
  .stat-row > .card { min-width: 42%; }
}