:root {
  --navy: #0f1f3d;
  --navy-light: #16305c;
  --gold: #d4a537;
  --gold-light: #f0cf7a;
  --bg: #f4f6fb;
  --card-bg: #ffffff;
  --text: #1c2431;
  --text-muted: #667085;
  --border: #e1e5ee;
  --danger: #c0392b;
  --success: #1e8e5a;
  --warning: #b8860b;
}

* { box-sizing: border-box; }

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

.app-header {
  background: var(--navy);
  color: #fff;
  padding: 14px 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 20px;
}

.brand-name { font-weight: 700; font-size: 1.3rem; color: var(--gold-light); }
.brand-sub { font-size: 1.05rem; opacity: 0.85; }

.tabs { display: flex; gap: 6px; flex-wrap: wrap; }

.tab-btn {
  background: transparent;
  border: 1px solid transparent;
  color: #cfd8e8;
  padding: 8px 14px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.92rem;
}

.tab-btn:hover { background: var(--navy-light); color: #fff; }
.tab-btn.active { background: var(--gold); color: var(--navy); font-weight: 600; }

main { max-width: 1100px; margin: 0 auto; padding: 24px; }

.tab-panel { display: none; }
.tab-panel.active { display: block; }

h2 { color: var(--navy); margin-top: 0; }
h3 { color: var(--navy-light); }

.panel-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 12px;
}

.btn {
  border: none;
  border-radius: 6px;
  padding: 9px 16px;
  font-size: 0.92rem;
  cursor: pointer;
  font-weight: 600;
}

.btn-primary { background: var(--gold); color: var(--navy); }
.btn-primary:hover { background: var(--gold-light); }

.btn-secondary { background: var(--navy-light); color: #fff; }
.btn-secondary:hover { background: var(--navy); }

.btn-danger { background: var(--danger); color: #fff; }
.btn-small { padding: 5px 10px; font-size: 0.82rem; margin-right: 4px; }

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 18px;
}

.stat-label { color: var(--text-muted); font-size: 0.85rem; }
.stat-value { font-size: 1.6rem; font-weight: 700; color: var(--navy); margin-top: 4px; }

.table-wrap { overflow-x: auto; background: var(--card-bg); border-radius: 10px; border: 1px solid var(--border); }

table { width: 100%; border-collapse: collapse; font-size: 0.92rem; }
th, td { padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--border); white-space: nowrap; }
th { background: #eef1f8; color: var(--navy); font-weight: 600; }
tbody tr:hover { background: #f8f9fd; }

.status-badge {
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: capitalize;
}
.status-unpaid { background: #fde2e1; color: var(--danger); }
.status-partial { background: #fff3cd; color: var(--warning); }
.status-paid { background: #d7f2e4; color: var(--success); }
.status-void { background: #e5e7eb; color: var(--text-muted); }

.form-row { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 10px; }
.form-field { display: flex; flex-direction: column; gap: 4px; flex: 1; min-width: 160px; }
.form-field label { font-size: 0.82rem; color: var(--text-muted); }
.form-field input, .form-field select, .form-field textarea,
select, input[type="text"], input[type="email"], input[type="date"], input[type="number"] {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.92rem;
  font-family: inherit;
}

.invoice-totals { display: flex; justify-content: space-between; align-items: flex-end; gap: 20px; margin: 16px 0; flex-wrap: wrap; }
.totals-summary { text-align: right; font-size: 0.95rem; }
.totals-summary .grand-total { font-size: 1.15rem; font-weight: 700; color: var(--navy); }

.form-actions { display: flex; gap: 10px; margin-top: 14px; }

.modal-backdrop {
  position: fixed; inset: 0; background: rgba(15, 31, 61, 0.55);
  display: flex; align-items: center; justify-content: center; z-index: 100;
}
.modal-backdrop.hidden { display: none; }
.modal {
  background: #fff; border-radius: 10px; width: 420px; max-width: 92vw;
  max-height: 88vh; overflow-y: auto; box-shadow: 0 20px 50px rgba(0,0,0,0.25);
}
.modal-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 18px; border-bottom: 1px solid var(--border);
}
.modal-head h3 { margin: 0; }
.modal-close { background: none; border: none; font-size: 1.4rem; cursor: pointer; color: var(--text-muted); }
.modal-body { padding: 18px; }

#toast-container { position: fixed; bottom: 20px; right: 20px; display: flex; flex-direction: column; gap: 8px; z-index: 200; }
.toast {
  background: var(--navy); color: #fff; padding: 10px 16px; border-radius: 8px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.2); font-size: 0.9rem;
}
.toast.error { background: var(--danger); }
.toast.success { background: var(--success); }

.icon-btn { background: none; border: none; cursor: pointer; color: var(--navy-light); font-size: 0.9rem; }

.muted-text { color: var(--text-muted); font-size: 0.9rem; max-width: 560px; }

.hidden { display: none !important; }

.header-actions { display: flex; align-items: center; gap: 10px; margin-left: auto; }
.current-user-email { color: #cfd8e8; font-size: 0.85rem; }

.login-screen {
  position: fixed; inset: 0; background: var(--navy);
  display: flex; align-items: center; justify-content: center; z-index: 300;
}
.login-card {
  background: var(--card-bg); border-radius: 12px; padding: 32px 28px;
  width: 340px; max-width: 90vw; box-shadow: 0 20px 60px rgba(0,0,0,0.35);
}
.login-card h1 { text-align: center; margin-top: 0; margin-bottom: 22px; font-size: 1.3rem; }
.login-error { color: var(--danger); font-size: 0.85rem; min-height: 1.2em; margin: 4px 0 0; }