:root{
  --primary:#2f6fed;
  --primary-dark:#1e4fb8;
  --success:#1fa971;
  --danger:#e5484d;
  --warning:#e8a13a;
  --bg:#f3f5fa;
  --card-bg:#ffffff;
  --text:#1c2333;
  --text-muted:#6b7280;
  --border:#e4e7ef;
  --sidebar-bg:#161b2c;
  --sidebar-text:#c7cbe0;
  --radius:10px;
  --shadow:0 2px 10px rgba(20,26,50,.06);
}
[data-theme="dark"]{
  --primary:#5b8def;
  --primary-dark:#4472d6;
  --success:#2fbf82;
  --danger:#f0555a;
  --warning:#ecb15a;
  --bg:#12141c;
  --card-bg:#1b1e29;
  --text:#e6e8f0;
  --text-muted:#9aa0b4;
  --border:#2b2f3d;
  --sidebar-bg:#0c0e16;
  --sidebar-text:#c7cbe0;
  --shadow:0 2px 10px rgba(0,0,0,.35);
}
[data-theme="dark"] .field input,
[data-theme="dark"] .field select,
[data-theme="dark"] .field textarea,
[data-theme="dark"] .toolbar input,
[data-theme="dark"] .toolbar select,
[data-theme="dark"] table.data-table th,
[data-theme="dark"] .btn.btn-secondary{
  background:#242836;
  color:var(--text);
}
[data-theme="dark"] .modal{background:var(--card-bg);}
[data-theme="dark"] .bulletin, [data-theme="dark"] .bulletin table th, [data-theme="dark"] .bulletin table td{
  background:#1b1e29;color:var(--text);border-color:var(--border);
}
*,*::before,*::after{box-sizing:border-box;}
html,body{height:100%;}
body{
  margin:0;
  font-family:"Segoe UI",Roboto,Arial,sans-serif;
  background:var(--bg);
  color:var(--text);
  font-size:14px;
  transition:background .2s ease,color .2s ease;
}
#app{display:flex;min-height:100vh;}

/* Sidebar */
.sidebar{
  width:250px;
  background:var(--sidebar-bg);
  color:var(--sidebar-text);
  flex-shrink:0;
  display:flex;
  flex-direction:column;
  transition:margin-left .2s ease;
}
.sidebar.collapsed{margin-left:-250px;}
.sidebar-brand{
  display:flex;align-items:center;gap:8px;
  padding:18px 20px;font-weight:700;font-size:18px;color:#fff;
  border-bottom:1px solid rgba(255,255,255,.08);
}
.sidebar-nav{display:flex;flex-direction:column;padding:10px;gap:2px;overflow-y:auto;}
.sidebar-nav a{
  color:var(--sidebar-text);
  text-decoration:none;
  padding:10px 12px;
  border-radius:8px;
  font-size:13.5px;
  white-space:nowrap;
}
.sidebar-nav a:hover{background:rgba(255,255,255,.06);color:#fff;}
.sidebar-nav a.active{background:var(--primary);color:#fff;}

/* Main */
.main{flex:1;display:flex;flex-direction:column;min-width:0;}
.topbar{
  height:60px;background:var(--card-bg);border-bottom:1px solid var(--border);
  display:flex;align-items:center;gap:14px;padding:0 20px;position:sticky;top:0;z-index:20;
}
.topbar h1{font-size:18px;margin:0;flex:1;}
.topbar-right{display:flex;align-items:center;gap:14px;}
.school-year-badge{background:#eef2ff;color:var(--primary-dark);padding:5px 10px;border-radius:20px;font-size:12px;font-weight:600;}
.user-badge{font-size:13px;color:var(--text-muted);}
.icon-btn{background:none;border:none;font-size:18px;cursor:pointer;color:var(--text);padding:4px 8px;border-radius:6px;}
.icon-btn:hover{background:var(--bg);}
.content{padding:22px;flex:1;overflow-x:auto;}

/* Cards / grid */
.cards-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:14px;margin-bottom:20px;}
.stat-card{background:var(--card-bg);border-radius:var(--radius);padding:16px;box-shadow:var(--shadow);border:1px solid var(--border);}
.stat-card .stat-value{font-size:26px;font-weight:700;}
.stat-card .stat-label{color:var(--text-muted);font-size:12.5px;margin-top:4px;}
.panel{background:var(--card-bg);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow);border:1px solid var(--border);margin-bottom:18px;}
.panel h2, .panel h3{margin-top:0;}

/* Toolbar */
.toolbar{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-bottom:14px;}
.toolbar input, .toolbar select{
  padding:8px 10px;border:1px solid var(--border);border-radius:8px;font-size:13px;background:#fff;
}
.toolbar .spacer{flex:1;}

/* Buttons */
.btn{
  display:inline-flex;align-items:center;gap:6px;
  padding:8px 14px;border-radius:8px;border:1px solid transparent;
  font-size:13px;cursor:pointer;font-weight:600;background:var(--primary);color:#fff;
}
.btn:hover{background:var(--primary-dark);}
.btn.btn-secondary{background:#fff;color:var(--text);border-color:var(--border);}
.btn.btn-secondary:hover{background:var(--bg);}
.btn.btn-danger{background:var(--danger);}
.btn.btn-danger:hover{background:#c73438;}
.btn.btn-success{background:var(--success);}
.btn.btn-sm{padding:5px 9px;font-size:12px;}
.btn:disabled{opacity:.5;cursor:not-allowed;}

/* Table */
.table-wrap{overflow-x:auto;}
table.data-table{width:100%;border-collapse:collapse;font-size:13px;}
table.data-table th, table.data-table td{padding:9px 10px;border-bottom:1px solid var(--border);text-align:left;white-space:nowrap;}
table.data-table th{background:#f8f9fd;color:var(--text-muted);font-weight:600;position:sticky;top:0;}
table.data-table tbody tr:hover{background:#f8f9ff;}
.table-actions{display:flex;gap:6px;}
.avatar{width:32px;height:32px;border-radius:50%;object-fit:cover;background:#dbe3ff;}
.avatar-lg{width:90px;height:90px;border-radius:12px;object-fit:cover;background:#dbe3ff;}

/* Badges */
.badge{padding:3px 9px;border-radius:20px;font-size:11px;font-weight:700;display:inline-block;}
.badge-success{background:#e3f9ef;color:var(--success);}
.badge-danger{background:#fdecec;color:var(--danger);}
.badge-warning{background:#fdf3e2;color:var(--warning);}
.badge-muted{background:#eef0f5;color:var(--text-muted);}
.badge-primary{background:#eaf0ff;color:var(--primary);}

/* Modal */
.modal-overlay{
  position:fixed;inset:0;background:rgba(15,18,32,.55);
  display:flex;align-items:flex-start;justify-content:center;
  padding:40px 16px;overflow-y:auto;z-index:1000;
}
.modal{
  background:#fff;border-radius:12px;max-width:640px;width:100%;
  box-shadow:0 20px 60px rgba(0,0,0,.3);
}
.modal-header{display:flex;align-items:center;justify-content:space-between;padding:16px 20px;border-bottom:1px solid var(--border);}
.modal-header h3{margin:0;font-size:16px;}
.modal-close{background:none;border:none;font-size:20px;cursor:pointer;color:var(--text-muted);}
.modal-body{padding:20px;max-height:70vh;overflow-y:auto;}
.modal-footer{padding:14px 20px;border-top:1px solid var(--border);display:flex;justify-content:flex-end;gap:8px;}

/* Forms */
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px 16px;}
.form-grid .full{grid-column:1/-1;}
.field label{display:block;font-size:12.5px;font-weight:600;margin-bottom:5px;color:var(--text-muted);}
.field input, .field select, .field textarea{
  width:100%;padding:8px 10px;border:1px solid var(--border);border-radius:8px;font-size:13px;font-family:inherit;background:#fff;
}
.field textarea{resize:vertical;}

/* Tabs */
.tabs{display:flex;gap:4px;border-bottom:1px solid var(--border);margin-bottom:16px;flex-wrap:wrap;}
.tab-btn{background:none;border:none;padding:9px 14px;cursor:pointer;font-size:13px;color:var(--text-muted);border-bottom:2px solid transparent;font-weight:600;}
.tab-btn.active{color:var(--primary);border-color:var(--primary);}

/* Toast */
.toast-root{position:fixed;bottom:20px;right:20px;z-index:2000;display:flex;flex-direction:column;gap:8px;}
.toast{background:#1c2333;color:#fff;padding:10px 16px;border-radius:8px;font-size:13px;box-shadow:var(--shadow);animation:fadein .2s ease;}
.toast.success{background:var(--success);}
.toast.error{background:var(--danger);}
@keyframes fadein{from{opacity:0;transform:translateY(8px);}to{opacity:1;transform:translateY(0);}}

/* Empty state */
.empty-state{text-align:center;padding:40px 10px;color:var(--text-muted);}

/* Help guide */
.help-hero{background:linear-gradient(120deg,#173b67 0%,var(--primary) 100%);color:#fff;border:0;overflow:hidden;}
.help-hero h2{font-size:24px;margin-bottom:8px;}
.help-hero p{max-width:720px;margin:0;color:rgba(255,255,255,.82);line-height:1.6;}
.help-search{position:relative;margin-top:18px;max-width:680px;}
.help-search input{width:100%;padding:13px 16px 13px 42px;border:0;border-radius:8px;font:inherit;color:var(--text);box-shadow:0 8px 24px rgba(0,0,0,.16);}
.help-search span{position:absolute;left:15px;top:11px;font-size:18px;}
.help-layout{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:18px;align-items:start;}
.help-section{scroll-margin-top:80px;}
.help-section h3{display:flex;align-items:center;gap:8px;margin-bottom:8px;color:var(--primary-dark);}
.help-section p,.help-section li{line-height:1.65;}
.help-section ul{padding-left:20px;margin-bottom:0;}
.help-index{position:sticky;top:78px;}
.help-index a{display:block;padding:7px 9px;color:var(--text-muted);text-decoration:none;border-left:2px solid var(--border);font-size:13px;}
.help-index a:hover{color:var(--primary);border-color:var(--primary);background:var(--bg);}
.creator-card{border-top:3px solid var(--primary);}
.creator-name{font-size:18px;font-weight:700;margin-bottom:4px;}
.creator-role{color:var(--text-muted);margin-top:0;}
.help-empty{display:none;}
@media (max-width:900px){
  .help-layout{grid-template-columns:1fr;}
  .help-index{display:none;}
}

/* Print */
.printable{display:none;}
@media print{
  .sidebar, .topbar, .toolbar, .table-actions, .btn, .no-print{display:none !important;}
  .content{padding:0;}
  .printable{display:block;}
  body *{visibility:hidden;}
  .printable, .printable *{visibility:visible;}
  .printable{position:absolute;top:0;left:0;width:100%;}
}

/* Bulletin */
.bulletin{border:1px solid #ccc;padding:20px;border-radius:8px;background:#fff;}
.school-logo-preview{display:block;width:90px;height:90px;object-fit:contain;margin-top:8px;border:1px solid var(--border);padding:4px;background:#fff;}
.bulletin-logo{width:76px;height:76px;object-fit:contain;vertical-align:middle;margin-right:10px;}
.pdf-export-root{position:fixed;left:0;top:0;width:794px;max-width:100vw;min-height:1123px;pointer-events:none;z-index:9999;background:#fff;color:#222;}
.bulletin-header{display:flex;justify-content:space-between;align-items:center;border-bottom:2px solid var(--primary);padding-bottom:10px;margin-bottom:16px;}
.bulletin-meta{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 18px;margin-bottom:14px;font-size:12px;}
.bulletin table{width:100%;border-collapse:collapse;}
.bulletin table th, .bulletin table td{border:1px solid #ccc;padding:9px 8px;font-size:12.5px;line-height:1.25;}
.bulletin .signature-row{display:flex;justify-content:space-between;margin-top:40px;}

/* Timetable grid */
.timetable-grid{display:grid;grid-template-columns:80px repeat(6,1fr);gap:1px;background:var(--border);border:1px solid var(--border);}
.timetable-grid .cell{background:#fff;padding:8px;min-height:50px;font-size:12px;}
.timetable-grid .head{background:#f8f9fd;font-weight:700;text-align:center;}
.timetable-slot{background:#eaf0ff;border-left:3px solid var(--primary);border-radius:4px;padding:4px 6px;font-size:11.5px;margin-bottom:3px;position:relative;}
.timetable-slot .del{position:absolute;top:2px;right:4px;cursor:pointer;color:var(--danger);font-weight:700;}

/* Responsive */
@media (max-width:900px){
  .sidebar{position:fixed;height:100vh;height:100dvh;z-index:50;margin-left:-250px;}
  .sidebar.open{margin-left:0;}
  .sidebar-nav{padding-top:24px;}
  .sidebar.open + .main .topbar{z-index:60;}
  .form-grid{grid-template-columns:1fr;}
  .content{padding:16px;}
  .topbar{padding-left:16px;padding-right:16px;}
}

/* Shared small-screen layout */
.content,.main,.panel{min-width:0;}
.table-wrap{max-width:100%;overscroll-behavior-x:contain;}
.toolbar>select,.toolbar>input,.toolbar>.field{min-width:0;max-width:100%;}
.timetable-grid-wrap{max-width:100%;overflow-x:auto;overscroll-behavior-x:contain;}
.timetable-grid{min-width:760px;}
.bulletin-table-wrap{max-width:100%;overflow-x:auto;overscroll-behavior-x:contain;}
.bulletin-table-wrap table{min-width:680px;}

@media (max-width:640px){
  .topbar{
    height:auto;min-height:60px;flex-wrap:wrap;gap:4px 8px;
    padding:8px 12px;
  }
  .topbar h1{flex:1;min-width:0;font-size:16px;line-height:1.2;overflow-wrap:anywhere;}
  .topbar-right{flex:1 0 100%;width:100%;min-width:0;justify-content:space-between;gap:6px;}
  .school-year-badge{max-width:45%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:11px;}
  .user-badge{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:12px;}
  .content{padding:12px 10px;overflow-x:hidden;}
  .panel{padding:12px;border-radius:8px;}
  .cards-grid{grid-template-columns:repeat(auto-fit,minmax(min(100%,160px),1fr));gap:10px;}
  .stat-card{padding:12px;}
  .stat-card .stat-value{font-size:22px;}
  .toolbar{align-items:stretch;gap:8px;}
  .toolbar .spacer{display:none;}
  .toolbar>select,.toolbar>input,.toolbar>.field{flex:1 1 145px;width:auto;}
  .toolbar>.btn{flex:1 1 145px;min-height:40px;justify-content:center;text-align:center;}
  .toolbar .field input,.toolbar .field select{width:100%;min-width:0;}
  .form-grid{grid-template-columns:minmax(0,1fr);gap:10px;}
  .form-grid .full{grid-column:1;}
  .modal-overlay{padding:12px 8px;}
  .modal{max-width:none;border-radius:8px;}
  .modal-header,.modal-body{padding:14px;}
  .modal-body{max-height:calc(100dvh - 150px);}
  .modal-footer{padding:12px 14px;flex-wrap:wrap;}
  .modal-footer .btn{flex:1 1 120px;justify-content:center;}
  .toast-root{left:10px;right:10px;bottom:10px;}
  .toast{max-width:100%;overflow-wrap:anywhere;}
  .help-hero h2{font-size:20px;}
  .bulletin{padding:12px;border-radius:6px;}
  .bulletin-header{flex-direction:column;align-items:flex-start;gap:10px;}
  .bulletin-header>div{max-width:100%;}
  .bulletin-header>div:last-child{text-align:left!important;}
  .bulletin-meta{grid-template-columns:minmax(0,1fr);gap:6px;}
  .bulletin .signature-row{gap:16px;flex-wrap:wrap;}
}

@media (max-width:380px){
  .content{padding:10px 8px;}
  .panel{padding:10px;}
  .topbar{padding-left:8px;padding-right:8px;}
  .topbar-right{gap:4px;}
  .school-year-badge{max-width:42%;padding:4px 6px;}
  .icon-btn{padding:4px 6px;}
  .toolbar>.btn{flex-basis:100%;}
}
.text-muted{color:var(--text-muted);}
.mt-0{margin-top:0;}
hr.sep{border:none;border-top:1px solid var(--border);margin:16px 0;}

/* Login screen */
#loginScreen{
  min-height:100vh;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,var(--primary) 0%,var(--primary-dark) 100%);padding:20px;
}
.login-card{
  background:var(--card-bg);border-radius:14px;padding:32px;width:100%;max-width:400px;
  box-shadow:0 20px 60px rgba(0,0,0,.25);
}
.login-brand{font-size:24px;font-weight:700;display:flex;align-items:center;gap:8px;margin-bottom:6px;}
.login-error{background:#fdecec;color:var(--danger);padding:8px 10px;border-radius:8px;font-size:12.5px;margin:10px 0;}
.login-demo-list{display:flex;flex-wrap:wrap;gap:6px;}
.login-card .field{margin-bottom:12px;}