:root {
  --primary-color: #1e3c72;
  --primary-dark: #122549;
  --accent-color: #ffb703;
  --success-color: #28a745;
  --danger-color: #dc3545;
  --warning-color: #ff9f1c;
  --bg-color: #f4f7fb;
  --card-bg: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --border-color: #e2e8f0;
}

* {
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, Roboto, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  margin: 0;
  padding: 0;
  line-height: 1.6;
}

/* --- Navigation Header --- */
.school-header {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: white;
  padding: 16px 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.12);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.school-header .brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.school-header h1 {
  margin: 0;
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.nav-links {
  display: flex;
  gap: 20px;
}

.nav-links a {
  color: #e2e8f0;
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  padding: 6px 12px;
  border-radius: 6px;
  transition: all 0.2s ease;
}

.nav-links a:hover, .nav-links a.active {
  color: white;
  background-color: rgba(255, 255, 255, 0.15);
}

/* --- Container & Cards --- */
.erp-container {
  max-width: 900px;
  margin: 40px auto;
  padding: 0 20px;
}

.erp-card {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 32px;
  box-shadow: 0 10px 30px rgba(30, 60, 114, 0.08);
  border: 1px solid var(--border-color);
}

.erp-card h2 {
  color: var(--primary-color);
  margin-top: 0;
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 12px;
  font-size: 1.35rem;
}

/* --- Form Elements --- */
.form-row {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.form-control {
  flex: 1;
  min-width: 220px;
  padding: 12px 16px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  font-size: 0.95rem;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-control:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(30, 60, 114, 0.12);
}

/* --- Buttons --- */
.btn-primary {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 12px 24px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}

.btn-primary:hover {
  background-color: var(--primary-dark);
}

.btn-success {
  background-color: var(--success-color);
  color: white;
  border: none;
  padding: 14px 28px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  width: 100%;
  transition: background 0.2s;
}

.btn-success:hover {
  background-color: #218838;
}

/* --- Tables --- */
.erp-table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
}

.erp-table th, .erp-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.erp-table th {
  background-color: #f8fafc;
  color: var(--primary-color);
  font-weight: 600;
}

/* --- Status Badges --- */
.badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.82rem;
  font-weight: 700;
}

.badge-pending {
  background-color: #fef3c7;
  color: #92400e;
}

.badge-paid {
  background-color: #d1fae5;
  color: #065f46;
}

/* --- Admin Tabs & Dropzone --- */
.admin-tabs {
  display: flex;
  gap: 10px;
  margin-bottom: 25px;
  border-bottom: 2px solid var(--border-color);
}

.tab-btn {
  background: none;
  border: none;
  padding: 12px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: 6px 6px 0 0;
  transition: all 0.2s;
}

.tab-btn.active {
  background-color: var(--primary-color);
  color: white;
}

.drop-zone {
  border: 2px dashed var(--primary-color);
  border-radius: 10px;
  padding: 35px 20px;
  text-align: center;
  background-color: #f8fafc;
  cursor: pointer;
  margin-bottom: 15px;
  transition: background 0.2s;
}

.drop-zone:hover {
  background-color: #f1f5f9;
}

.format-guide {
  background-color: #eef2ff;
  border-left: 4px solid var(--primary-color);
  padding: 12px 16px;
  margin-bottom: 20px;
  font-size: 0.88rem;
  color: #334155;
  border-radius: 0 6px 6px 0;
}

.format-guide code {
  background: #e2e8f0;
  padding: 2px 6px;
  border-radius: 4px;
  font-family: monospace;
}

.summary-box {
  background-color: #f8fafc;
  border-radius: 8px;
  padding: 16px;
  margin-top: 20px;
  display: flex;
  justify-content: space-between;
  font-weight: bold;
}

/* Print Rules */
@media print {
  .no-print, .school-header { display: none !important; }
  body { background: white; }
  .erp-card { box-shadow: none; border: none; padding: 0; }
}