*{margin:0;padding:0;box-sizing:border-box}
:root{--primary:#4A90E2;--primary-dark:#3A7BD5;--primary-light:#EBF3FE;--accent:#FF8C42;--accent-light:#FFF3EB;--success:#4CAF50;--success-dark:#388E3C;--danger:#EF5350;--danger-dark:#D32F2F;--warning:#FFB74D;--warning-dark:#F9A825;--info:#4A90E2;--bg:#F5F8FC;--card:#fff;--border:#E3EBF6;--text:#2C3E50;--text-secondary:#607D8B;--text-muted:#90A4AE;--sidebar-bg:#fff;--sidebar-text:#546E7A;--sidebar-active-bg:#EBF3FE;--sidebar-active-text:#4A90E2;--radius:12px;--radius-sm:8px;--shadow:0 2px 8px rgba(44,62,80,.06);--shadow-md:0 4px 12px rgba(44,62,80,.08);--shadow-lg:0 8px 30px rgba(44,62,80,.12)}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans SC",sans-serif;font-size:14px;color:var(--text);background:var(--bg);line-height:1.6}
.layout{display:flex;min-height:100vh}

/* ===== Sidebar ===== */
.sidebar{width:240px;background:var(--sidebar-bg);color:var(--sidebar-text);position:fixed;top:0;left:0;bottom:0;overflow-y:auto;z-index:100;border-right:1px solid var(--border);scrollbar-width:thin;scrollbar-color:rgba(0,0,0,.08) transparent}
.sidebar::-webkit-scrollbar{width:4px}
.sidebar::-webkit-scrollbar-thumb{background:rgba(0,0,0,.08);border-radius:10px}
.sidebar-header{padding:24px 20px 20px;border-bottom:1px solid var(--border);background:linear-gradient(135deg,#4A90E2 0%,#5C9CE6 100%);margin:0}
.sidebar-header h2{font-size:18px;color:#fff;font-weight:700;letter-spacing:.5px}
.nav-menu{list-style:none;padding:8px 0}
.nav-menu li{margin:0}
.nav-group{padding:20px 20px 8px;font-size:15px;color:var(--text);letter-spacing:.5px;font-weight:700;display:flex;align-items:center;gap:10px;cursor:pointer;user-select:none}
.nav-group .group-icon{font-size:18px}
.nav-group .group-arrow{font-size:12px;margin-left:auto;transition:transform .25s ease;opacity:.5}
.nav-group.collapsed .group-arrow{transform:rotate(-90deg)}
.nav-group::after{display:none}
.nav-group-items{overflow:hidden;transition:max-height .3s ease}
.nav-group-items.collapsed{max-height:0!important}
.nav-group-items ul{list-style:none;padding:2px 0}
.nav-link{display:block;padding:11px 20px 11px 42px;color:var(--sidebar-text);text-decoration:none;transition:all .2s;font-size:15px;border-left:3px solid transparent;border-radius:0;margin:1px 8px 1px 0}
.nav-link:hover{background:var(--primary-light);color:var(--primary);border-left-color:var(--primary)}
.nav-link.active{background:var(--sidebar-active-bg);color:var(--sidebar-active-text);border-left-color:var(--primary);font-weight:600}
.nav-separator{height:1px;background:var(--border);margin:8px 20px}

/* ===== Main Content ===== */
.main-content{margin-left:240px;flex:1;min-height:100vh;background:var(--bg);display:flex;flex-direction:column}
.top-bar{background:var(--card);padding:14px 28px;display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:50;box-shadow:0 1px 3px rgba(44,62,80,.04)}
.page-title{font-size:17px;font-weight:700;color:var(--text)}
.user-info{display:flex;align-items:center;gap:14px;font-size:13px;color:var(--text-secondary)}
.content{padding:24px 28px;flex:1;min-width:0}

/* ===== Cards ===== */
.card{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);margin-bottom:20px;border:1px solid var(--border);overflow:hidden}
.card-header{padding:16px 22px;border-bottom:1px solid var(--border);font-weight:600;font-size:15px;color:var(--text);display:flex;justify-content:space-between;align-items:center;background:#FAFCFF}
.card-body{padding:22px}

/* ===== Forms ===== */
.form-group{margin-bottom:18px}
.form-group label{display:block;margin-bottom:6px;font-weight:600;color:var(--text);font-size:13px}
.form-control{width:100%;padding:9px 14px;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:14px;transition:all .2s;background:#fff;color:var(--text)}
.form-control:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(74,144,226,.15)}
.form-inline{display:flex;flex-wrap:wrap;gap:14px;align-items:end}
.form-inline .form-group{margin-bottom:0}
.form-inline .form-group label{margin-bottom:5px}

/* ===== Buttons ===== */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:8px 18px;border:none;border-radius:var(--radius-sm);cursor:pointer;font-size:14px;font-weight:500;text-decoration:none;text-align:center;transition:all .2s;line-height:1.4}
.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover{background:var(--primary-dark);box-shadow:0 3px 10px rgba(74,144,226,.3)}
.btn-success{background:var(--success);color:#fff}.btn-success:hover{background:var(--success-dark);box-shadow:0 3px 10px rgba(76,175,80,.3)}
.btn-danger{background:var(--danger);color:#fff}.btn-danger:hover{background:var(--danger-dark);box-shadow:0 3px 10px rgba(239,83,80,.3)}
.btn-warning{background:var(--warning);color:#fff}.btn-warning:hover{background:var(--warning-dark);box-shadow:0 3px 10px rgba(255,183,77,.3)}
.btn-default{background:#F0F4F8;color:var(--text);border:1px solid var(--border)}.btn-default:hover{background:#E3EBF6}
.btn-sm{padding:5px 12px;font-size:12px;border-radius:6px}
.btn-block{display:block;width:100%}

/* ===== Tables ===== */
.table{width:100%;border-collapse:separate;border-spacing:0}
.table th,.table td{padding:11px 14px;text-align:left;border-bottom:1px solid var(--border);font-size:13px}
.table th{background:#F5F8FC;font-weight:600;color:var(--text-secondary);font-size:12px;text-transform:uppercase;letter-spacing:.3px;white-space:nowrap}
.table td{color:var(--text)}
.table thead th:first-child{border-radius:var(--radius-sm) 0 0 0}
.table thead th:last-child{border-radius:0 var(--radius-sm) 0 0}
.table-striped tbody tr:nth-child(even){background:#FAFCFF}
.table-striped tbody tr:hover{background:var(--primary-light)}
.table-bordered th,.table-bordered td{border:1px solid var(--border)}
.table-responsive{overflow-x:auto;border-radius:var(--radius-sm);width:100%}
.col-action{width:120px;white-space:nowrap;text-align:center}
.col-action .btn-sm{padding:3px 10px;font-size:12px;border-radius:6px;letter-spacing:.2px}
.col-action .btn-sm+.btn-sm{margin-left:4px}

/* ===== Alerts ===== */
.alert{padding:14px 18px;border-radius:var(--radius-sm);margin-bottom:16px;font-size:14px;font-weight:500}
.alert-error{background:#FFEBEE;color:var(--danger-dark);border:1px solid #FFCDD2}
.alert-info{background:var(--primary-light);color:#1565C0;border:1px solid #BBDEFB}

/* ===== Pagination ===== */
.pagination{display:flex;justify-content:center;align-items:center;gap:6px;padding:18px 0;flex-wrap:wrap}
.pagination .pg-btn{display:inline-flex;align-items:center;justify-content:center;min-width:36px;height:36px;padding:0 10px;border:1px solid var(--border);border-radius:var(--radius-sm);background:var(--card);color:var(--text);cursor:pointer;font-size:13px;font-weight:500;text-decoration:none;transition:all .2s}
.pagination .pg-btn:hover{background:var(--primary);color:#fff;border-color:var(--primary);box-shadow:0 2px 8px rgba(74,144,226,.25)}
.pagination .pg-btn.active{background:var(--primary);color:#fff;border-color:var(--primary)}
.pagination .pg-btn.disabled{color:var(--text-muted);cursor:not-allowed;background:#F5F8FC;border-color:var(--border)}
.pagination .pg-btn.disabled:hover{background:#F5F8FC;color:var(--text-muted);border-color:var(--border);box-shadow:none}
.pagination .pg-info{font-size:13px;color:var(--text-secondary);margin:0 10px}

/* ===== Modals ===== */
.modal{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(44,62,80,.4);backdrop-filter:blur(4px);display:flex;justify-content:center;align-items:center;z-index:1000}
.modal-content{background:var(--card);border-radius:var(--radius);width:520px;max-width:90%;max-height:90vh;overflow-y:auto;box-shadow:var(--shadow-lg)}
.modal-header{padding:20px 24px;border-bottom:1px solid var(--border)}
.modal-header h3{font-size:17px;font-weight:700}
.modal-body{padding:24px}
.modal-footer{padding:16px 24px;border-top:1px solid var(--border);text-align:right;display:flex;gap:10px;justify-content:flex-end}

/* ===== Login ===== */
.login-container{min-height:100vh;display:flex;justify-content:center;align-items:center;background:linear-gradient(135deg,#4A90E2 0%,#5CA0E8 30%,#FF8C42 70%,#FFB74D 100%);position:relative;overflow:hidden}
.login-container::before{content:'';position:absolute;width:400px;height:400px;border-radius:50%;background:rgba(255,255,255,.08);top:-100px;right:-100px}
.login-container::after{content:'';position:absolute;width:300px;height:300px;border-radius:50%;background:rgba(255,255,255,.06);bottom:-80px;left:-80px}
.login-box{background:var(--card);border-radius:20px;padding:44px 40px;width:460px;max-width:90%;box-shadow:0 20px 60px rgba(44,62,80,.15);position:relative;z-index:1}
.login-header{text-align:center;margin-bottom:28px}
.login-icon{font-size:44px;margin-bottom:8px}
.login-title{font-size:22px;color:var(--text);font-weight:800;margin:0}
.login-form .login-row{display:flex;align-items:center;margin-bottom:16px;gap:12px}
.login-form .login-row label{flex-shrink:0;width:56px;text-align:right;font-size:14px;color:var(--text-secondary);font-weight:500}
.login-form .login-row .form-control{flex:1;padding:10px 14px;font-size:14px;border-radius:10px}
.login-form .btn{padding:12px;font-size:15px;border-radius:10px;font-weight:600;margin-top:4px;background:linear-gradient(135deg,#4A90E2,#5CA0E8);border:none}
.login-form .btn:hover{box-shadow:0 4px 15px rgba(74,144,226,.4);transform:translateY(-1px)}
.login-footer{text-align:center;margin-top:20px;color:var(--text-muted);font-size:12px}

/* ===== Misc ===== */
.score-tag{display:inline-block;padding:3px 10px;margin:2px;border-radius:20px;background:var(--primary-light);font-size:12px;font-weight:500;color:var(--primary)}
.score-tag.fail{background:#FFEBEE;color:var(--danger)}
.text-danger{color:var(--danger)}
.text-muted{color:var(--text-muted)}
.quick-links .card-body{display:flex;flex-wrap:wrap;gap:12px}
.quick-link{display:block;padding:14px 22px;background:#F5F8FC;border-radius:var(--radius-sm);text-decoration:none;color:var(--text);transition:all .2s;font-weight:500}
.quick-link:hover{background:var(--primary);color:#fff;transform:translateY(-1px);box-shadow:0 4px 12px rgba(74,144,226,.3)}
.bar{height:22px;background:linear-gradient(90deg,var(--primary),var(--accent));border-radius:6px;min-width:2px}
.stat-section{margin-bottom:24px}
.welcome{margin-bottom:24px}
.welcome h2{color:var(--text);font-weight:700}
.announcement-item{padding:12px 0;border-bottom:1px solid #F0F4F8}
.announcement-item:last-child{border-bottom:none}
.announcement-item.top{border-left:3px solid var(--accent);padding-left:12px;background:var(--accent-light);border-radius:0 var(--radius-sm) var(--radius-sm) 0;margin:0 -22px;padding-right:22px}
.announcement-item .time{color:var(--text-muted);font-size:12px}
.pull-right{float:right}
.score-input{width:72px;padding:6px 8px;text-align:center;border:1px solid var(--border);border-radius:6px;font-size:14px;transition:all .2s}
.score-input:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(74,144,226,.15)}
.error-page{text-align:center;padding:80px 20px}
.error-page h1{font-size:56px;color:var(--danger);margin-bottom:16px;font-weight:800}
select.form-control{appearance:auto}
.stats-row{display:flex;gap:16px;margin-bottom:24px;flex-wrap:wrap}
.stat-card{background:var(--card);border-radius:var(--radius);padding:24px;text-align:center;flex:1;min-width:130px;box-shadow:var(--shadow);border:1px solid var(--border)}
.stat-number{font-size:36px;font-weight:800;color:var(--primary);line-height:1.2}
.stat-label{font-size:13px;color:var(--text-secondary);margin-top:6px;font-weight:500}
.dashboard .welcome{margin-bottom:24px}
.dashboard .welcome h2{color:var(--text);font-weight:700}
.page-header{margin-bottom:20px}
.page-header h2{font-size:20px;font-weight:700;color:var(--text)}

/* ===== Print ===== */
@media print{
.sidebar,.top-bar,.no-print{display:none!important}
.main-content{margin-left:0!important}
.content{padding:10px!important}
.card{box-shadow:none!important;break-inside:avoid;border:1px solid #ddd}
.table th,.table td{padding:6px 8px;font-size:12px}
.page-header h2{font-size:18px}
body{background:#fff}
}
.print-header{text-align:center;margin-bottom:20px;padding-bottom:12px;border-bottom:2px solid #333}
.print-header h1{font-size:20px;margin-bottom:4px}
.print-header p{color:#666;font-size:13px}
.print-footer{text-align:center;margin-top:20px;padding-top:12px;border-top:1px solid #ccc;color:#999;font-size:12px}