:root {
  --bg: #f1f5f9;
  --card: #ffffff;
  --ink: #0f172a;
  --muted: #64748b;
  --brand: #0d9488;
  --brand-dark: #0f766e;
  --accent: #2563eb;
  --line: #e2e8f0;
  --paid: #16a34a;
  --paid-bg: #dcfce7;
  --pending: #d97706;
  --pending-bg: #fef3c7;
  --error: #b91c1c;
  --error-bg: #fee2e2;
  --radius: 10px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--ink);
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 24px;
  background: var(--card);
  border-bottom: 1px solid var(--line);
  flex-wrap: wrap;
}

.topbar nav {
  display: flex;
  align-items: center;
  gap: 16px;
}

.topbar nav a {
  color: var(--ink);
  text-decoration: none;
  font-weight: 600;
}

.topbar nav a.active { color: var(--brand); }

.who { color: var(--muted); font-size: 14px; }

.logo { height: 32px; }

.logo-large { height: 56px; margin-bottom: 8px; }

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 16px 64px;
}

h1 { font-size: 24px; margin: 8px 0 16px; }
h2 { font-size: 17px; margin: 0 0 12px; }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 16px;
  overflow-x: auto;
}

.notice {
  background: #ecfeff;
  border: 1px solid #a5f3fc;
  border-radius: var(--radius);
  padding: 12px 16px;
  margin-bottom: 16px;
  line-height: 1.6;
}

.muted { color: var(--muted); font-size: 14px; }

table { border-collapse: collapse; width: 100%; }

th {
  text-align: left;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
  padding: 8px 10px;
  border-bottom: 1px solid var(--line);
}

td { padding: 10px; border-bottom: 1px solid var(--line); }

tbody tr:last-child td { border-bottom: none; }

.discount { color: var(--brand-dark); font-weight: 600; }

.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
}

.badge-paid { background: var(--paid-bg); color: var(--paid); }
.badge-pending { background: var(--pending-bg); color: var(--pending); }

.paid-at { color: var(--muted); font-size: 12px; margin-left: 6px; }

form label { display: block; font-size: 13px; color: var(--muted); margin-bottom: 4px; }

input[type="text"],
input[type="password"],
input[type="number"],
select {
  width: 100%;
  padding: 9px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 14px;
  background: #fff;
  margin-bottom: 12px;
}

input:focus, select:focus {
  outline: 2px solid var(--brand);
  outline-offset: -1px;
}

.btn {
  border: none;
  border-radius: 8px;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); }
.btn-small { padding: 6px 14px; }
.btn-block { width: 100%; }
.btn-link {
  border: none;
  background: none;
  color: var(--muted);
  font-size: 14px;
  cursor: pointer;
  padding: 0;
  text-decoration: underline;
}

.row-form {
  display: flex;
  align-items: flex-end;
  gap: 12px;
  flex-wrap: wrap;
}

.row-form label { margin-bottom: 4px; }
.row-form select, .row-form input { width: auto; min-width: 140px; margin-bottom: 0; }

.inline-form { display: inline; }

.invoice-form {
  display: flex;
  align-items: flex-end;
  gap: 12px;
  flex-wrap: wrap;
}

.invoice-form label { min-width: 90px; margin-bottom: 0; }
.invoice-form input, .invoice-form select { margin-bottom: 0; }

.inv-month { font-weight: 700; min-width: 110px; }
.inv-num { color: var(--muted); min-width: 60px; }

.error-box {
  background: var(--error-bg);
  color: var(--error);
  padding: 10px 14px;
  border-radius: 8px;
  font-weight: 600;
}

.ok-box {
  background: var(--paid-bg);
  color: var(--paid);
  padding: 10px 14px;
  border-radius: 8px;
  font-weight: 600;
}

.login-body {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 16px;
}

.login-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px;
  width: 100%;
  max-width: 380px;
  text-align: center;
}

.login-card h1 { font-size: 20px; }

.login-card form { text-align: left; margin-top: 16px; }