/* ── Variables ─────────────────────────────────────────── */
:root {
  --sidebar-w: 240px;
  --topbar-h: 56px;
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --info: #3b82f6;
  --bg: #f1f5f9;
  --card: #ffffff;
  --sidebar-bg: #1e293b;
  --sidebar-text: #94a3b8;
  --sidebar-hover: rgba(255,255,255,0.06);
  --sidebar-active-bg: rgba(99,102,241,0.18);
  --sidebar-active-text: #a5b4fc;
  --text: #0f172a;
  --text-2: #64748b;
  --border: #e2e8f0;
  --radius: 8px;
  --radius-lg: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
}

/* ── Reset ─────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; font-size: 14px; background: var(--bg); color: var(--text); line-height: 1.5; }
a { text-decoration: none; color: inherit; }
button { cursor: pointer; border: none; background: none; font: inherit; }
input, select, textarea { font: inherit; }
table { border-collapse: collapse; width: 100%; }

/* ── Layout ────────────────────────────────────────────── */
#app { display: flex; min-height: 100vh; }

#sidebar {
  width: var(--sidebar-w);
  min-height: 100vh;
  background: var(--sidebar-bg);
  color: var(--sidebar-text);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0; left: 0;
  z-index: 100;
  transition: transform .25s ease;
}
#sidebar.collapsed { transform: translateX(calc(-1 * var(--sidebar-w))); }

.sidebar-header { padding: 18px 16px; border-bottom: 1px solid rgba(255,255,255,0.07); }
.logo { display: flex; align-items: center; gap: 10px; }
.logo-icon { font-size: 22px; }
.logo-text { font-size: 16px; font-weight: 700; color: #e2e8f0; }

.sidebar-nav { flex: 1; padding: 12px 8px; display: flex; flex-direction: column; gap: 2px; }
.sidebar-footer { padding: 8px; border-top: 1px solid rgba(255,255,255,0.07); }

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border-radius: var(--radius);
  color: var(--sidebar-text);
  font-size: 13.5px;
  transition: background .15s, color .15s;
}
.nav-item:hover { background: var(--sidebar-hover); color: #cbd5e1; }
.nav-item.active { background: var(--sidebar-active-bg); color: var(--sidebar-active-text); font-weight: 600; }
.nav-icon { font-size: 16px; width: 20px; text-align: center; }

#main-wrapper {
  flex: 1;
  margin-left: var(--sidebar-w);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  transition: margin-left .25s ease;
}
#main-wrapper.expanded { margin-left: 0; }

#topbar {
  height: var(--topbar-h);
  background: var(--card);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 20px;
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--shadow);
}
#page-title { font-size: 16px; font-weight: 600; flex: 1; }
#topbar-actions { display: flex; align-items: center; gap: 8px; }

#content { padding: 20px; flex: 1; }

/* ── Banner ────────────────────────────────────────────── */
.banner { padding: 12px 16px; border-radius: var(--radius); margin-bottom: 16px; font-size: 13px; display: flex; align-items: center; gap: 8px; }
.banner-warning { background: #fef3c7; border: 1px solid #fcd34d; color: #92400e; }
.banner-link { margin-left: auto; color: var(--primary); font-weight: 600; }

/* ── Cards ─────────────────────────────────────────────── */
.card { background: var(--card); border-radius: var(--radius-lg); box-shadow: var(--shadow); padding: 20px; }
.card-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; }
.card-title { font-size: 15px; font-weight: 600; }

/* ── Stat Cards ────────────────────────────────────────── */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 14px; margin-bottom: 20px; }
.stat-card {
  background: var(--card);
  border-radius: var(--radius-lg);
  padding: 16px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 6px;
  border-left: 4px solid var(--primary);
}
.stat-card.green { border-color: var(--success); }
.stat-card.yellow { border-color: var(--warning); }
.stat-card.red { border-color: var(--danger); }
.stat-card.blue { border-color: var(--info); }
.stat-label { font-size: 12px; color: var(--text-2); font-weight: 500; }
.stat-value { font-size: 26px; font-weight: 700; color: var(--text); }

/* ── Charts grid ───────────────────────────────────────── */
.charts-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 16px; margin-bottom: 20px; }
.chart-card { background: var(--card); border-radius: var(--radius-lg); padding: 16px; box-shadow: var(--shadow); }
.chart-card canvas { max-height: 220px; }

/* ── Toolbar ───────────────────────────────────────────── */
.toolbar { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; }
.search-box { flex: 1; min-width: 200px; max-width: 340px; position: relative; }
.search-box input { width: 100%; padding: 8px 12px 8px 34px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--card); font-size: 13px; }
.search-box::before { content: '🔍'; position: absolute; left: 10px; top: 50%; transform: translateY(-50%); font-size: 13px; }

/* ── Filters ───────────────────────────────────────────── */
.filter-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; }
.filter-row select { padding: 7px 10px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--card); font-size: 13px; color: var(--text); cursor: pointer; }

/* ── Table ─────────────────────────────────────────────── */
.table-wrap { overflow-x: auto; border-radius: var(--radius-lg); box-shadow: var(--shadow); }
.data-table { width: 100%; background: var(--card); }
.data-table th { background: #f8fafc; padding: 10px 14px; text-align: left; font-size: 12px; font-weight: 600; color: var(--text-2); text-transform: uppercase; letter-spacing: .04em; border-bottom: 1px solid var(--border); white-space: nowrap; }
.data-table td { padding: 10px 14px; border-bottom: 1px solid var(--border); font-size: 13px; vertical-align: middle; }
.data-table tr:last-child td { border-bottom: none; }
.data-table tbody tr:hover { background: #f8fafc; }
.data-table .actions { display: flex; gap: 6px; }

/* ── Badges ────────────────────────────────────────────── */
.badge { display: inline-flex; align-items: center; padding: 2px 9px; border-radius: 999px; font-size: 11px; font-weight: 600; }
.badge-green { background: #d1fae5; color: #065f46; }
.badge-red { background: #fee2e2; color: #991b1b; }
.badge-blue { background: #dbeafe; color: #1e40af; }
.badge-yellow { background: #fef3c7; color: #92400e; }
.badge-gray { background: #f1f5f9; color: #475569; }
.badge-purple { background: #ede9fe; color: #5b21b6; }

/* ── Buttons ───────────────────────────────────────────── */
.btn { display: inline-flex; align-items: center; gap: 6px; padding: 8px 16px; border-radius: var(--radius); font-size: 13px; font-weight: 500; transition: opacity .15s, background .15s; cursor: pointer; border: none; }
.btn:hover { opacity: .88; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-success { background: var(--success); color: #fff; }
.btn-danger { background: var(--danger); color: #fff; }
.btn-warning { background: var(--warning); color: #fff; }
.btn-outline { background: transparent; border: 1px solid var(--border); color: var(--text); }
.btn-outline:hover { background: var(--bg); }
.btn-sm { padding: 5px 10px; font-size: 12px; }
.icon-btn { padding: 6px; border-radius: var(--radius); color: var(--text-2); font-size: 16px; transition: background .15s; }
.icon-btn:hover { background: var(--bg); }

/* ── Forms ─────────────────────────────────────────────── */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.form-grid.single { grid-template-columns: 1fr; }
.form-group { display: flex; flex-direction: column; gap: 5px; }
.form-group.full { grid-column: 1 / -1; }
.form-group label { font-size: 12px; font-weight: 600; color: var(--text-2); text-transform: uppercase; letter-spacing: .04em; }
.form-control { padding: 8px 10px; border: 1px solid var(--border); border-radius: var(--radius); font-size: 13px; background: #fff; transition: border-color .15s; }
.form-control:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(99,102,241,.12); }
.form-control[readonly] { background: var(--bg); color: var(--text-2); }
textarea.form-control { resize: vertical; min-height: 70px; }
.skills-grid { display: flex; flex-wrap: wrap; gap: 8px; }
.skill-check { display: flex; align-items: center; gap: 5px; font-size: 13px; cursor: pointer; }
.skill-check input[type=checkbox], .skill-check input[type=radio] { accent-color: var(--primary); }
/* override form-group label uppercase for checkbox/radio option text */
.form-group label.skill-check { text-transform: none; font-size: 13px; font-weight: 500; color: var(--text-1); letter-spacing: 0; }

/* ── Modal ─────────────────────────────────────────────── */
#modal-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,.45);
  z-index: 200;
  display: flex; align-items: center; justify-content: center;
  padding: 20px;
}
#modal {
  background: var(--card);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 680px;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  box-shadow: 0 20px 60px rgba(0,0,0,.25);
}
.modal-header { display: flex; align-items: center; justify-content: space-between; padding: 16px 20px; border-bottom: 1px solid var(--border); }
.modal-header h3 { font-size: 16px; font-weight: 600; }
.modal-body { padding: 20px; overflow-y: auto; flex: 1; }
.modal-footer { padding: 14px 20px; border-top: 1px solid var(--border); display: flex; gap: 8px; justify-content: flex-end; }

/* ── Toast ─────────────────────────────────────────────── */
#toast-container { position: fixed; bottom: 20px; right: 20px; z-index: 999; display: flex; flex-direction: column; gap: 8px; }
.toast {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 16px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  font-size: 13px;
  font-weight: 500;
  color: #fff;
  min-width: 240px;
  animation: slideIn .2s ease;
}
.toast-success { background: var(--success); }
.toast-error { background: var(--danger); }
.toast-warning { background: var(--warning); }
.toast-info { background: var(--info); }
@keyframes slideIn { from { transform: translateX(40px); opacity: 0; } to { transform: none; opacity: 1; } }

/* ── Misc ──────────────────────────────────────────────── */
.hidden { display: none !important; }
.mt-4 { margin-top: 16px; }
.mb-4 { margin-bottom: 16px; }
.empty-state { text-align: center; padding: 48px 20px; color: var(--text-2); }
.empty-state .empty-icon { font-size: 48px; margin-bottom: 12px; }
.empty-state p { font-size: 15px; }
.section-title { font-size: 15px; font-weight: 600; margin-bottom: 14px; padding-bottom: 8px; border-bottom: 1px solid var(--border); }
.profile-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.profile-item { display: flex; flex-direction: column; gap: 2px; }
.profile-item .label { font-size: 11px; color: var(--text-2); font-weight: 600; text-transform: uppercase; }
.profile-item .value { font-size: 13px; font-weight: 500; }
.attendance-bar { height: 8px; border-radius: 4px; background: var(--border); overflow: hidden; }
.attendance-bar-fill { height: 100%; border-radius: 4px; background: var(--success); transition: width .4s; }
.loading-overlay { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 12px; padding: 60px; }
.spinner { width: 36px; height: 36px; border: 3px solid var(--border); border-top-color: var(--primary); border-radius: 50%; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Attendance marking ────────────────────────────────── */
.attend-table .present-btn, .attend-table .absent-btn {
  padding: 4px 12px; border-radius: 999px; font-size: 12px; font-weight: 600; cursor: pointer; border: 2px solid transparent;
}
.attend-table .present-btn { background: #d1fae5; color: #065f46; border-color: #6ee7b7; }
.attend-table .absent-btn { background: #fee2e2; color: #991b1b; border-color: #fca5a5; }
.attend-table .present-btn.selected { background: var(--success); color: #fff; }
.attend-table .absent-btn.selected { background: var(--danger); color: #fff; }

/* ── Classroom student list ────────────────────────────── */
.student-tag { display: inline-flex; align-items: center; gap: 4px; background: var(--bg); border: 1px solid var(--border); border-radius: 999px; padding: 3px 10px; font-size: 12px; }
.student-tag .remove-student { color: var(--danger); cursor: pointer; font-weight: 700; }

/* ── Reports ───────────────────────────────────────────── */
.report-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 14px; margin-bottom: 20px; }
.report-card { background: var(--card); border-radius: var(--radius-lg); padding: 20px; box-shadow: var(--shadow); text-align: center; cursor: pointer; transition: box-shadow .2s, transform .15s; border: 2px solid transparent; }
.report-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); border-color: var(--primary); }
.report-card .rc-icon { font-size: 32px; margin-bottom: 8px; }
.report-card .rc-title { font-size: 14px; font-weight: 600; }
.report-card .rc-desc { font-size: 12px; color: var(--text-2); margin-top: 4px; }

/* ── Responsive ────────────────────────────────────────── */
@media (max-width: 768px) {
  #sidebar { transform: translateX(calc(-1 * var(--sidebar-w))); }
  #sidebar.open { transform: none; }
  #main-wrapper { margin-left: 0; }
  .form-grid { grid-template-columns: 1fr; }
  .form-group.full { grid-column: 1; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .charts-grid { grid-template-columns: 1fr; }
  #modal { max-height: 100vh; border-radius: 0; }
}