:root {
  --green: #015140; --green-2: #013A2E; --cream: #F5F2EA; --paper: #FFFDF9; --zebra: #F1ECE2;
  --ink: #14231E; --muted: #6B7570; --line: #E2DCCF; --err: #B42318; --warn: #B54708;
  --radius: 12px; --shadow: 0 1px 2px rgba(20,35,30,.06), 0 8px 24px rgba(20,35,30,.06);
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { font-family: 'Poppins', system-ui, sans-serif; background: var(--cream); color: var(--ink); font-size: 14px; line-height: 1.45; }
button, input, select, textarea { font: inherit; color: inherit; }
h1 { font-size: 20px; margin: 0; font-weight: 600; letter-spacing: -.01em; }
.muted { color: var(--muted); font-size: 12px; }
.hint { color: var(--muted); font-size: 12px; margin: 8px 0 0; }
[hidden] { display: none !important; }

/* top bar */
.topbar { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 24px; padding: 10px 24px; background: var(--green); color: var(--cream); }
.brand { display: flex; align-items: center; gap: 10px; }
.brand-logo { width: 40px; height: 40px; border-radius: 50%; background: var(--cream); color: var(--green); display: grid; place-items: center; box-shadow: 0 0 0 3px #0B634F; flex: none; }
.brand-logo svg { width: 24px; height: auto; }
.brand b { display: block; font-weight: 600; letter-spacing: .14em; text-transform: uppercase; font-size: 13px; }
.brand small { display: block; font-size: 11px; opacity: .7; }
.tabs { display: flex; gap: 4px; flex: 1; overflow-x: auto; }
.tab { background: none; border: 0; color: var(--cream); opacity: .75; padding: 8px 14px; border-radius: 999px; cursor: pointer; white-space: nowrap; font-weight: 500; }
.tab:hover { opacity: 1; background: rgba(255,255,255,.08); }
.tab.active { opacity: 1; background: var(--cream); color: var(--green); }
.status { font-size: 11px; opacity: .7; white-space: nowrap; }

main { padding: 24px; max-width: 1500px; margin: 0 auto; }
.split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 24px; align-items: start; }
.panel { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow); }
.panel.wide { max-width: 1100px; margin: 0 auto; }
.panel-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 8px; flex-wrap: wrap; }

fieldset { border: 0; border-top: 1px solid var(--line); margin: 14px 0 0; padding: 14px 0 0; }
legend { font-size: 11px; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--green); padding: 0 8px 0 0; }
.grid { display: grid; gap: 12px; }
.g2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.g3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.span2 { grid-column: span 2; }
label { display: flex; flex-direction: column; gap: 4px; font-size: 12px; font-weight: 500; color: var(--muted); }
fieldset > label { margin-top: 10px; }
input, select, textarea { width: 100%; border: 1px solid var(--line); background: #fff; border-radius: 8px; padding: 9px 11px; font-size: 14px; color: var(--ink); transition: border-color .15s, box-shadow .15s; }
textarea { resize: vertical; }
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--green); box-shadow: 0 0 0 3px rgba(1,81,64,.12); }
.invalid { border-color: var(--err) !important; box-shadow: 0 0 0 3px rgba(180,35,24,.1); }
.err-msg { color: var(--err); font-size: 12px; margin-top: 4px; }

/* items */
.items-head, .item-row { display: grid; grid-template-columns: minmax(0, 1fr) 70px 110px 110px 34px; gap: 8px; align-items: start; }
.items-head { font-size: 11px; color: var(--muted); font-weight: 600; text-transform: uppercase; letter-spacing: .08em; padding: 0 2px 6px; }
.items-head span:nth-child(n+3) { text-align: right; }
#items { display: flex; flex-direction: column; gap: 8px; margin-bottom: 10px; border-radius: 8px; }
#items.invalid { padding: 6px; }
.item-row { background: var(--zebra); padding: 8px; border-radius: 10px; }
.item-main { display: flex; flex-direction: column; gap: 6px; }
.item-main .sub { font-size: 12px; padding: 7px 10px; }
.item-amt { text-align: right; padding-top: 10px; font-weight: 600; font-variant-numeric: tabular-nums; }
.icon-btn { width: 34px; height: 38px; border: 0; background: none; font-size: 20px; color: var(--muted); cursor: pointer; border-radius: 8px; }
.icon-btn:hover { background: #fff; color: var(--err); }

/* buttons */
.btn { border: 1px solid var(--green); background: #fff; color: var(--green); padding: 10px 18px; border-radius: 999px; cursor: pointer; font-weight: 600; font-size: 14px; display: inline-flex; align-items: center; justify-content: center; gap: 6px; white-space: nowrap; }
.btn:hover { background: var(--zebra); }
.btn.primary { background: var(--green); color: var(--cream); }
.btn.primary:hover { background: var(--green-2); }
.btn.ghost { background: transparent; }
.btn.sm { padding: 6px 12px; font-size: 12px; }
.btn.danger { border-color: transparent; color: var(--err); background: transparent; }
.btn.danger:hover { background: #FEF3F2; }
.btn:disabled { opacity: .6; cursor: progress; }
.btn.file { cursor: pointer; flex-direction: row; color: var(--green); }
.row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }

.sticky-actions { position: sticky; bottom: 0; margin: 18px -22px -22px; padding: 14px 22px; background: rgba(255,253,249,.96); backdrop-filter: blur(6px); border-top: 1px solid var(--line); border-radius: 0 0 var(--radius) var(--radius); display: flex; gap: 16px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.btns { display: flex; gap: 8px; flex-wrap: wrap; }
.totals { display: flex; gap: 6px 18px; flex-wrap: wrap; font-size: 12px; color: var(--muted); align-items: baseline; }
.totals div { display: flex; gap: 6px; align-items: baseline; }
.totals b { color: var(--ink); font-variant-numeric: tabular-nums; }
.totals .grand b { color: var(--green); font-size: 16px; }
.totals .words { flex-basis: 100%; font-style: italic; }

/* preview */
.preview { position: sticky; top: 84px; }
.preview-label { font-size: 11px; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--green); margin-bottom: 8px; }
.preview iframe { width: 100%; height: calc(100vh - 130px); min-height: 560px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; box-shadow: var(--shadow); }

/* history */
.filters { margin: 12px 0; }
.filters input { flex: 1; min-width: 200px; }
.filters select { width: auto; }
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 10px; }
table.hist { width: 100%; border-collapse: collapse; font-size: 13px; }
.hist th { text-align: left; background: var(--green); color: var(--cream); font-weight: 600; font-size: 11px; letter-spacing: .08em; text-transform: uppercase; padding: 10px 12px; }
.hist td { padding: 10px 12px; border-top: 1px solid var(--line); vertical-align: top; }
.hist tr:nth-child(even) td { background: #FAF7F1; }
.hist .num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.hist .actions { white-space: nowrap; text-align: right; }
.hist .empty { text-align: center; color: var(--muted); padding: 40px 12px; }
.pill { display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: 11px; font-weight: 600; }
.pill.paid { background: var(--green); color: var(--cream); }
.pill.part { background: #FEF0C7; color: var(--warn); }
.pill.due { background: #FEE4E2; color: var(--err); }
.pill.rec { background: var(--zebra); color: var(--green); }

.sig { display: flex; flex-direction: column; gap: 8px; }
#sigPreview { min-height: 56px; border: 1px dashed var(--line); border-radius: 8px; display: grid; place-items: center; background: #fff; padding: 6px; }
#sigPreview img { max-height: 52px; max-width: 100%; }

/* toasts */
#toasts { position: fixed; right: 20px; bottom: 20px; display: flex; flex-direction: column; gap: 8px; z-index: 50; }
.toast { background: var(--ink); color: #fff; padding: 10px 16px; border-radius: 10px; font-size: 13px; box-shadow: var(--shadow); transform: translateY(8px); opacity: 0; transition: all .25s; max-width: 360px; }
.toast.show { transform: none; opacity: 1; }
.toast.ok { background: var(--green); }
.toast.err { background: var(--err); }
.toast.warn { background: var(--warn); }

@media (max-width: 1100px) {
  .split { grid-template-columns: 1fr; }
  .preview { display: none; }
}
@media (max-width: 640px) {
  main { padding: 12px; }
  .topbar { padding: 10px 16px; gap: 12px; flex-wrap: wrap; }
  .status { display: none; }
  .tabs { order: 3; flex-basis: 100%; }
  .panel { padding: 16px; }
  .g2, .g3 { grid-template-columns: 1fr; }
  .span2 { grid-column: auto; }
  .items-head { display: none; }
  .item-row { grid-template-columns: 1fr 1fr; }
  .item-main { grid-column: 1 / -1; }
  .item-amt { padding-top: 0; text-align: left; }
  .item-amt::before { content: 'Amount: '; color: var(--muted); font-weight: 400; }
  .item-row .del { justify-self: end; }
  .sticky-actions { margin: 16px -16px -16px; padding: 12px 16px; gap: 8px; }
  .tab { padding: 7px 10px; font-size: 13px; }
  .btns { width: 100%; display: grid; grid-template-columns: auto 1fr; }
  .btns .btn { padding: 10px 14px; }
}