/* =====================================================
   ΣΧΟΛΗ ΧΟΡΟΥ – Main Stylesheet
   ===================================================== */
:root {
  --sidebar-w: 240px;
  --sidebar-bg: #111827;
  --sidebar-hover: #1f2937;
  --sidebar-active: #4f6ef7;
  --accent: #4f6ef7;
  --accent-hover: #3b55d9;
  --accent-light: #eef1fe;
  --bg: #f3f4f6;
  --surface: #ffffff;
  --border: #e5e7eb;
  --text: #111827;
  --text-2: #6b7280;
  --text-3: #9ca3af;
  --success: #22c55e;
  --success-bg: #f0fdf4;
  --success-border: #bbf7d0;
  --danger: #ef4444;
  --danger-bg: #fef2f2;
  --danger-border: #fecaca;
  --warning: #f59e0b;
  --warning-bg: #fffbeb;
  --warning-border: #fde68a;
  --info: #3b82f6;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.04);
  --shadow: 0 4px 12px rgba(0,0,0,.08);
  --radius: 10px;
  --radius-sm: 6px;
  --font: 'Inter', 'Segoe UI', system-ui, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 15px; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  display: flex;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Sidebar ─────────────────────────────────────── */
.sidebar {
  width: var(--sidebar-w);
  min-height: 100vh;
  background: var(--sidebar-bg);
  display: flex;
  flex-direction: column;
  position: fixed;
  left: 0; top: 0;
  z-index: 100;
  -webkit-transition: -webkit-transform .25s ease;
          transition: transform .25s ease;
}

.sidebar-logo {
  padding: 24px 20px 16px;
  border-bottom: 1px solid rgba(255,255,255,.06);
}
.sidebar-logo h1 {
  font-size: .95rem;
  font-weight: 700;
  color: #fff;
  line-height: 1.2;
}
.sidebar-logo small {
  font-size: .72rem;
  color: rgba(255,255,255,.4);
  font-weight: 400;
}

.sidebar-nav {
  flex: 1;
  padding: 12px 0;
  overflow-y: auto;
}

.nav-section {
  padding: 14px 20px 4px;
  font-size: .68rem;
  font-weight: 600;
  letter-spacing: .06em;
  color: rgba(255,255,255,.3);
  text-transform: uppercase;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 20px;
  color: rgba(255,255,255,.65);
  font-size: .875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all .15s;
  border-left: 3px solid transparent;
}
.nav-item:hover { background: var(--sidebar-hover); color: #fff; text-decoration: none; }
.nav-item.active {
  background: rgba(79,110,247,.15);
  color: #fff;
  border-left-color: var(--accent);
}
.nav-item svg { flex-shrink: 0; opacity: .75; }
.nav-item.active svg { opacity: 1; }

/* ── Nav submenus ─────────────────────────────────── */
.nav-group-toggle {
  width: 100%;
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
  font-size: inherit;
  font-family: inherit;
  color: rgba(255,255,255,.6);
}
.nav-group-toggle:hover { color: #fff; }
.nav-sub {
  display: none;
  background: rgba(0,0,0,.15);
}
.nav-group.open .nav-sub { display: block; }
.nav-group.open .nav-chevron { transform: rotate(180deg); }
.nav-sub-item {
  padding-left: 36px !important;
  font-size: .83rem !important;
  border-left: none !important;
}
.nav-sub-item.active {
  background: rgba(79,110,247,.2);
  color: #fff;
}

.sidebar-footer {
  padding: 16px 20px;
  border-top: 1px solid rgba(255,255,255,.06);
  font-size: .75rem;
  color: rgba(255,255,255,.3);
}

/* ── Main content ────────────────────────────────── */
.main {
  margin-left: var(--sidebar-w);
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* ── Top bar ─────────────────────────────────────── */
.topbar {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 28px;
  height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 50;
}
.topbar-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
}
.topbar-actions { display: flex; align-items: center; gap: 10px; }

/* ── Page content ────────────────────────────────── */
.page-content {
  padding: 28px;
  flex: 1;
}

/* ── KPI Cards ───────────────────────────────────── */
.kpi-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.kpi-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 20px 22px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.kpi-card .kpi-label {
  font-size: .75rem;
  color: var(--text-2);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: .04em;
}
.kpi-card .kpi-value {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1;
}
.kpi-card .kpi-sub {
  font-size: .78rem;
  color: var(--text-3);
}
.kpi-card.accent  { border-top: 3px solid var(--accent); }
.kpi-card.success { border-top: 3px solid var(--success); }
.kpi-card.danger  { border-top: 3px solid var(--danger); }
.kpi-card.warning { border-top: 3px solid var(--warning); }

/* ── Cards / Panels ──────────────────────────────── */
.card {
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}
.card-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.card-title {
  font-size: .9rem;
  font-weight: 600;
  color: var(--text);
}
.card-body { padding: 20px; }

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 20px; }

/* ── Tables ──────────────────────────────────────── */
.table-wrap { overflow-x: auto; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: .875rem;
}
thead th {
  background: #f9fafb;
  padding: 10px 14px;
  text-align: left;
  font-weight: 600;
  font-size: .75rem;
  color: var(--text-2);
  text-transform: uppercase;
  letter-spacing: .05em;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}
tbody tr { border-bottom: 1px solid #f3f4f6; transition: background .1s; }
tbody tr:hover { background: #fafafa; }
tbody tr:last-child { border-bottom: none; }
tbody td { padding: 12px 14px; vertical-align: middle; }
tbody td.mono { font-family: monospace; font-size: .82rem; }

/* ── Badges ──────────────────────────────────────── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 9px;
  border-radius: 20px;
  font-size: .73rem;
  font-weight: 600;
}
.badge-success { background: var(--success-bg); color: #15803d; border: 1px solid var(--success-border); }
.badge-danger  { background: var(--danger-bg);  color: #b91c1c; border: 1px solid var(--danger-border); }
.badge-warning { background: var(--warning-bg); color: #92400e; border: 1px solid var(--warning-border); }
.badge-neutral { background: #f3f4f6; color: var(--text-2); border: 1px solid var(--border); }
.badge-accent  { background: var(--accent-light); color: var(--accent); border: 1px solid #c7d0fd; }

/* ── Buttons ─────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: .85rem;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all .15s;
  white-space: nowrap;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); }
.btn-secondary { background: var(--surface); color: var(--text); border-color: var(--border); }
.btn-secondary:hover { background: #f9fafb; }
.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { background: #dc2626; }
.btn-success { background: var(--success); color: #fff; }
.btn-success:hover { background: #16a34a; }
.btn-sm { padding: 5px 10px; font-size: .78rem; }
.btn-icon { padding: 6px; border-radius: var(--radius-sm); background: none; border: none; cursor: pointer; color: var(--text-2); display: inline-flex; align-items: center; transition: all .15s; }
.btn-icon:hover { background: #f3f4f6; color: var(--text); }
.btn-icon.danger:hover { background: var(--danger-bg); color: var(--danger); }

/* ── Forms ───────────────────────────────────────── */
.form-group { margin-bottom: 16px; }
.form-label {
  display: block;
  margin-bottom: 5px;
  font-size: .82rem;
  font-weight: 600;
  color: var(--text);
}
.form-label .req { color: var(--danger); }
.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 9px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: .875rem;
  font-family: var(--font);
  color: var(--text);
  background: var(--surface);
  transition: border-color .15s, box-shadow .15s;
  outline: none;
}
.form-input:focus, .form-select:focus, .form-textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(79,110,247,.12);
}
.form-textarea { resize: vertical; min-height: 80px; }
.form-hint { font-size: .75rem; color: var(--text-3); margin-top: 4px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.form-row.cols-3 { grid-template-columns: 1fr 1fr 1fr; }

/* ── Modal ───────────────────────────────────────── */
.modal-backdrop {
  display: none;
  position: fixed; inset: 0;
  background: rgba(0,0,0,.45);
  z-index: 200;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.modal-backdrop.open { display: flex; }
.modal {
  background: var(--surface);
  border-radius: var(--radius);
  width: 100%;
  max-width: 600px;
  max-height: 92vh;
  overflow-y: auto;
  box-shadow: 0 20px 60px rgba(0,0,0,.25);
  animation: modalIn .18s ease;
}
.modal-lg { max-width: 820px; }
@keyframes modalIn { from { transform: translateY(16px); opacity: 0; } to { transform: none; opacity: 1; } }
.modal-header {
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.modal-title { font-size: 1rem; font-weight: 700; }
.modal-close { background: none; border: none; cursor: pointer; color: var(--text-2); padding: 4px; border-radius: 4px; transition: all .15s; }
.modal-close:hover { background: #f3f4f6; color: var(--text); }
.modal-body { padding: 24px; }
.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: flex-end;
  gap: 10px;
}

/* ── Filters bar ─────────────────────────────────── */
.filters-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.filters-bar .form-input,
.filters-bar .form-select { width: auto; }
.filters-bar .spacer { flex: 1; }

/* ── Alerts ──────────────────────────────────────── */
.alert {
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: .875rem;
  margin-bottom: 16px;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}
.alert-success { background: var(--success-bg); color: #15803d; border: 1px solid var(--success-border); }
.alert-danger   { background: var(--danger-bg);  color: #b91c1c; border: 1px solid var(--danger-border); }
.alert-warning  { background: var(--warning-bg); color: #92400e; border: 1px solid var(--warning-border); }
.alert-info     { background: #eff6ff; color: #1d4ed8; border: 1px solid #bfdbfe; }

/* ── Toast ───────────────────────────────────────── */
#toast {
  position: fixed;
  bottom: 24px; right: 24px;
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.toast-msg {
  padding: 12px 18px;
  border-radius: var(--radius-sm);
  font-size: .875rem;
  font-weight: 500;
  box-shadow: var(--shadow);
  animation: toastIn .2s ease;
  max-width: 320px;
}
.toast-success { background: #111827; color: #fff; }
.toast-error   { background: var(--danger); color: #fff; }
@keyframes toastIn { from { transform: translateX(16px); opacity: 0; } to { transform: none; opacity: 1; } }

/* ── Empty state ─────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 48px 24px;
  color: var(--text-3);
}
.empty-state svg { opacity: .3; margin-bottom: 12px; }
.empty-state p { font-size: .9rem; }

/* ── Utility ─────────────────────────────────────── */
.text-right { text-align: right; }
.text-center { text-align: center; }
.text-muted { color: var(--text-2); }
.text-danger { color: var(--danger); }
.text-success { color: var(--success); }
.text-warning { color: var(--warning); }
.fw-600 { font-weight: 600; }
.mb-16 { margin-bottom: 16px; }
.mb-20 { margin-bottom: 20px; }
.mt-8  { margin-top: 8px; }
.d-flex { display: flex; }
.align-center { align-items: center; }
.gap-8  { gap: 8px; }
.gap-12 { gap: 12px; }
.flex-1 { flex: 1; }
.hidden { display: none !important; }

/* ── Sidebar collapse (desktop) ──────────────────── */
body.sidebar-collapsed .sidebar {
  -webkit-transform: translateX(-100%);
          transform: translateX(-100%);
}
body.sidebar-collapsed .main {
  margin-left: 0;
}
/* Smooth transition on main when sidebar collapses – Safari-safe */
.main {
  -webkit-transition: margin-left .25s ease;
          transition: margin-left .25s ease;
}

/* Overlay behind sidebar on mobile */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.45);
  z-index: 99;
}
.sidebar-overlay.visible { display: block; }

/* ── Responsive ──────────────────────────────────── */
@media (max-width: 768px) {
  .sidebar { transform: translateX(-100%); }
  .sidebar.open { transform: none; }
  .main { margin-left: 0; }
  .form-row { grid-template-columns: 1fr; }
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .kpi-grid { grid-template-columns: 1fr 1fr; }
}

/* ── Chart canvas ────────────────────────────────── */
.chart-container { position: relative; width: 100%; }

/* ── Student card (list) ─────────────────────────── */
.student-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  transition: background .1s;
}
.student-card:last-child { border-bottom: none; }
.student-card:hover { background: #fafafa; }
.student-avatar {
  width: 40px; height: 40px;
  border-radius: 50%;
  background: var(--accent-light);
  color: var(--accent);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: .95rem;
  flex-shrink: 0;
}
.student-info { flex: 1; min-width: 0; }
.student-name { font-weight: 600; font-size: .9rem; color: var(--text); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.student-meta { font-size: .78rem; color: var(--text-3); margin-top: 2px; }
.student-actions { display: flex; gap: 6px; }

/* ── Payment row amount colors ───────────────────── */
.amount-positive { color: var(--success); font-weight: 600; }
.amount-negative { color: var(--danger);  font-weight: 600; }

/* ── Birthday banner ─────────────────────────────── */
.birthday-banner {
  background: linear-gradient(135deg, #fef3c7, #fde68a);
  border: 1px solid var(--warning-border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: .85rem;
  color: #78350f;
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
}

/* ── Debt indicator ──────────────────────────────── */
.debt-bar-wrap { display: flex; align-items: center; gap: 8px; }
.debt-bar-bg { flex: 1; height: 6px; border-radius: 99px; background: #e5e7eb; overflow: hidden; }
.debt-bar-fill { height: 100%; border-radius: 99px; background: var(--danger); transition: width .4s; }

/* ── Print ───────────────────────────────────────── */
@media print {
  .sidebar, .topbar, .btn, .filters-bar { display: none !important; }
  .main { margin-left: 0; }
  .page-content { padding: 0; }
  table { font-size: 11px; }
}