:root {
  --bg: #f3f4f6; --card: #ffffff; --text: #1f2430; --muted: #6b7280;
  --accent: #2563eb; --accent-dark: #1e40af; --border: #d8dce3;
  --error-bg: #fee2e2; --error-text: #991b1b;
  --ok-bg: #dcfce7; --ok-text: #14532d;
  --info-bg: #e0ecff; --info-text: #1e3a8a;
  --warn: #b45309;
}
* { box-sizing: border-box; }
body { margin: 0; font: 15px/1.5 -apple-system, "Segoe UI", Roboto, Arial, sans-serif; background: var(--bg); color: var(--text); }
main { max-width: 1000px; margin: 24px auto 64px; padding: 0 16px; }
nav { display: flex; align-items: center; gap: 18px; background: var(--card); border-bottom: 1px solid var(--border); padding: 10px 24px; }
nav .brand { font-weight: 700; }
nav .spacer { flex: 1; }
nav .user { color: var(--muted); }
nav a { color: var(--accent); text-decoration: none; }
nav form.inline { display: inline; }
h1 { font-size: 24px; margin: 18px 0 8px; }
h2 { font-size: 18px; margin: 0 0 12px; }
.hint { color: var(--muted); margin-top: 0; }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 20px; margin: 16px 0; }
.card.narrow { max-width: 420px; margin: 60px auto; }
.badge { font-size: 12px; background: var(--info-bg); color: var(--info-text); border-radius: 6px; padding: 2px 8px; vertical-align: middle; }
label { display: block; margin: 10px 0; font-weight: 600; }
label input, .bulk { display: block; width: 100%; margin-top: 4px; font: inherit; font-weight: 400; padding: 8px 10px; border: 1px solid var(--border); border-radius: 8px; }
.row { display: flex; gap: 10px; align-items: flex-end; flex-wrap: wrap; margin-top: 10px; }
.row.fields label { flex: 1; min-width: 220px; margin: 0; }
.rate-wrap { display: flex; gap: 6px; }
.rate-wrap input { flex: 1; }
.rate-status { display: block; font-weight: 400; color: var(--muted); min-height: 18px; }
.rate-status.warn { color: var(--warn); }
button { font: inherit; padding: 8px 16px; border-radius: 8px; border: 1px solid var(--border); background: #fff; cursor: pointer; }
button:hover { border-color: var(--accent); }
button.primary { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; }
button.primary:hover { background: var(--accent-dark); }
button.primary.big { padding: 12px 28px; font-size: 17px; }
button.ghost { background: transparent; color: var(--muted); }
button.link { background: none; border: none; color: var(--accent); padding: 0; }
button:disabled { opacity: .5; cursor: wait; }
.new-invoice { width: 160px; padding: 8px 10px; border: 1px solid var(--border); border-radius: 8px; font: inherit; }
.new-invoice.invalid { border-color: #dc2626; background: var(--error-bg); }
table.invoice-table, table.history { border-collapse: collapse; width: 100%; margin: 10px 0; }
table.invoice-table th, table.history th { text-align: left; color: var(--muted); font-weight: 600; padding: 4px 8px; border-bottom: 1px solid var(--border); }
table.invoice-table td, table.history td { padding: 4px 8px; border-bottom: 1px solid #eceef2; vertical-align: top; }
table.invoice-table input { width: 110px; padding: 5px 8px; border: 1px solid var(--border); border-radius: 6px; font: inherit; }
tr.dup td { background: #fef3c7; }
tr.dup .inv-num { border-color: var(--warn); }
.alert { border-radius: 8px; padding: 10px 14px; margin: 12px 0; }
.alert.error { background: var(--error-bg); color: var(--error-text); }
.alert.success { background: var(--ok-bg); color: var(--ok-text); }
.alert.info { background: var(--info-bg); color: var(--info-text); }
.alert a.download { font-weight: 700; color: inherit; }
details { margin-top: 8px; }
details pre { white-space: pre-wrap; font-size: 13px; }
td.params { font-size: 13px; color: var(--muted); }
.submit-card { text-align: center; }
#result { text-align: left; }