:root {
  --bg: #0e1014;
  --card: #151823;
  --line: #232a42;
  --text: #e0e3f1;
  --muted: #9aa3b2;
  --accent: #3b79ff;
  --danger: #ff4d4f;
}

body {
  margin: 0;
  font-family: "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

.invoice {
  max-width: 1000px;
  margin: 40px auto;
  padding: 30px;
  background: var(--card);
  border-radius: 10px;
  box-shadow: 0 0 12px rgba(0,0,0,0.15);
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 40px;
}

.topbar nav a.btn {
  margin-right: 10px;
  text-decoration: none;
  background: var(--accent);
  color: white;
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 14px;
  box-shadow: 0 0 6px rgba(59, 121, 255, 0.3);
}

.topbar nav a.btn:hover {
  background: #2a66db;
}

.invoice h1 {
  font-size: 28px;
  color: var(--accent);
  border-bottom: 1px solid var(--line);
  padding-bottom: 10px;
  margin-bottom: 30px;
}

.row {
  display: flex;
  flex-wrap: wrap;
  gap: 30px;
}

.space-between {
  justify-content: space-between;
}

.invoice .row > div {
  flex: 1;
  min-width: 250px;
}

.info-bar {
  background: #1f2638;
  padding: 14px 20px;
  border-radius: 8px;
  font-size: 14px;
  color: var(--muted);
  margin: 30px 0;
  display: flex;
  gap: 20px;
  justify-content: space-between;
}

.invoice-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 20px;
  border: 1px solid var(--line);
}

.invoice-table th {
  background: var(--accent);
  color: white;
  padding: 12px;
  text-align: left;
  font-size: 13px;
  font-weight: 600;
}

.invoice-table td {
  padding: 12px;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
  color: var(--text);
}

.invoice-table tr:last-child td {
  border-bottom: none;
}

.totals {
  margin-top: 30px;
  text-align: right;
}

.totals p {
  margin: 4px 0;
  font-size: 15px;
  color: var(--text);
}

.signatures {
  display: flex;
  justify-content: space-between;
  margin-top: 40px;
  gap: 20px;
  flex-wrap: wrap;
}

.sig-box {
  flex: 1;
  text-align: left;
}

.sig-box canvas {
  border: 1px dashed var(--line);
  margin-top: 6px;
  background: #0e111b;
  width: 100%;
  max-width: 300px;
  height: 100px;
}

.sig-date {
  font-size: 13px;
  color: var(--muted);
  margin-top: 6px;
}