:root {
  --bg: #f4f6f8;
  --card: #fff;
  --ink: #1a1d21;
  --muted: #5c6570;
  --line: #d7dde3;
  --accent: #005bff;
  --danger: #c62828;
  --ok: #1b7f3a;
  font-family: "Segoe UI", system-ui, sans-serif;
}
html, body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  min-height: 800px;
}
.wrap {
  max-width: 920px;
  margin: 0 auto;
  padding: 20px 16px 48px;
}
h1 { font-size: 22px; margin: 0 0 8px; }
h2 { font-size: 18px; margin: 16px 0 8px; }
.lead, .hint, .msg { color: var(--muted); font-size: 14px; line-height: 1.45; }
.tabs { display: flex; gap: 8px; margin: 16px 0; flex-wrap: wrap; }
.tabs button {
  border: 1px solid var(--line);
  background: var(--card);
  padding: 8px 14px;
  cursor: pointer;
  border-radius: 6px;
}
.tabs button.on { background: var(--accent); color: #fff; border-color: var(--accent); }
form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 12px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
}
label { display: flex; flex-direction: column; gap: 4px; font-size: 13px; }
label.wide { grid-column: 1 / -1; }
input, select {
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 4px;
  font-size: 14px;
}
.row { grid-column: 1 / -1; display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
button, a.btn {
  background: var(--accent);
  color: #fff;
  border: 0;
  border-radius: 6px;
  padding: 8px 14px;
  cursor: pointer;
  font-size: 14px;
  text-decoration: none;
  display: inline-block;
}
a.btn.ghost, button.ghost { background: #2b3440; }
button[type="button"]#btn-ping,
button#btn-tariff,
button#btn-products,
button#btn-batch,
button#btn-upload { background: #2b3440; }
#btn-apply, #btn-apply-batch { background: var(--ok); }
table { width: 100%; border-collapse: collapse; margin-top: 12px; font-size: 13px; background: var(--card); }
th, td { border-bottom: 1px solid var(--line); padding: 8px; text-align: left; }
.msg.err { color: var(--danger); }
.msg.ok { color: var(--ok); }
.confirm-box {
  margin-top: 16px;
  padding: 12px;
  border: 1px dashed var(--line);
  border-radius: 8px;
  background: #fff;
}
code { font-size: 12px; }
@media (max-width: 640px) {
  form { grid-template-columns: 1fr; }
}