/* 基础样式 - 学员管理系统 */
:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --success: #16a34a;
    --warning: #d97706;
    --danger: #dc2626;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --sidebar-w: 240px;
}

* { margin:0;padding:0;box-sizing:border-box }
body { font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;background:var(--gray-50);color:var(--gray-800);min-height:100vh }

/* 布局 */
.app-layout { display:flex;min-height:100vh }
.sidebar { width:var(--sidebar-w);background:var(--gray-900);color:#fff;flex-shrink:0;display:flex;flex-direction:column }
.main { flex:1;display:flex;flex-direction:column;min-width:0 }
.topbar { height:56px;background:#fff;border-bottom:1px solid var(--gray-200);display:flex;align-items:center;justify-content:space-between;padding:0 24px;flex-shrink:0 }
.content { flex:1;padding:24px;overflow-y:auto }

/* 侧边栏 */
.sidebar-logo { padding:20px;font-size:18px;font-weight:700;border-bottom:1px solid rgba(255,255,255,.1) }
.sidebar-nav { flex:1;padding:12px 0 }
.sidebar-nav a { display:flex;align-items:center;gap:10px;padding:10px 20px;color:rgba(255,255,255,.7);text-decoration:none;font-size:14px;transition:all .2s }
.sidebar-nav a:hover,.sidebar-nav a.active { background:rgba(255,255,255,.1);color:#fff }
.sidebar-user { padding:16px 20px;border-top:1px solid rgba(255,255,255,.1);font-size:13px;color:rgba(255,255,255,.6) }
.sidebar-user strong { display:block;color:#fff;margin-bottom:4px }
.sidebar-user a { color:var(--danger);text-decoration:none;font-size:12px }

/* 卡片 */
.card { background:#fff;border-radius:8px;box-shadow:0 1px 3px rgba(0,0,0,.08);margin-bottom:20px }
.card-header { padding:16px 20px;border-bottom:1px solid var(--gray-200);font-weight:600;font-size:15px;display:flex;align-items:center;justify-content:space-between }
.card-body { padding:20px }

/* 统计卡片 */
.stats-grid { display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:16px;margin-bottom:24px }
.stat-card { background:#fff;border-radius:8px;padding:20px;box-shadow:0 1px 3px rgba(0,0,0,.08) }
.stat-card .stat-label { font-size:13px;color:var(--gray-500);margin-bottom:6px }
.stat-card .stat-value { font-size:28px;font-weight:700;color:var(--gray-800) }
.stat-card .stat-sub { font-size:12px;color:var(--gray-400);margin-top:4px }

/* 加载动画 */
.spinner { width:16px;height:16px;border:2px solid var(--gray-200);border-top-color:var(--primary);border-radius:50%;animation:spin .8s linear infinite;flex-shrink:0 }
@keyframes spin { to { transform:rotate(360deg) } }

/* 表格 */
table { width:100%;border-collapse:collapse }
th,td { padding:8px 10px;text-align:left;border-bottom:1px solid var(--gray-200);font-size:13px;white-space:nowrap }
th { background:var(--gray-50);font-weight:600;color:var(--gray-600) }
tr:hover { background:var(--gray-50) }

/* 单元格超长省略展示（hover title 看全文） */
.cell-name { max-width:76px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap }
.cell-remark { max-width:150px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap }

/* 标签 */
.badge { display:inline-block;padding:2px 8px;border-radius:12px;font-size:11px;font-weight:500 }
.badge-success { background:#dcfce7;color:var(--success) }
.badge-warning { background:#fef3c7;color:var(--warning) }
.badge-danger { background:#fee2e2;color:var(--danger) }
.badge-info { background:#dbeafe;color:var(--primary) }
.badge-gray { background:var(--gray-100);color:var(--gray-500) }

/* 按钮 */
.btn { display:inline-flex;align-items:center;gap:6px;padding:8px 16px;border-radius:6px;font-size:13px;font-weight:500;cursor:pointer;border:none;transition:all .2s;text-decoration:none }
.btn-primary { background:var(--primary);color:#fff }
.btn-primary:hover { background:var(--primary-dark) }
.btn-success { background:var(--success);color:#fff }
.btn-update { background:linear-gradient(135deg,#4f8df9 0%,#2f6ff2 100%);color:#fff;box-shadow:0 1px 4px rgba(47,111,242,.3) }
.btn-update:hover { background:linear-gradient(135deg,#3f7df0 0%,#1f5fe3 100%);box-shadow:0 3px 10px rgba(47,111,242,.4);transform:translateY(-1px) }
.btn-update:active { transform:translateY(0) }
.btn-danger { background:var(--danger);color:#fff }
.btn-outline { background:#fff;border:1px solid var(--gray-300);color:var(--gray-600) }
.btn-outline:hover { border-color:var(--primary);color:var(--primary) }
.btn-disabled { background:var(--gray-200,#e2e8f0);color:var(--gray-400,#a0aec0);cursor:not-allowed }
.btn-sm { padding:4px 10px;font-size:12px }

/* 表单 */
.form-group { margin-bottom:16px }
.form-group label { display:block;font-size:13px;font-weight:500;color:var(--gray-700);margin-bottom:6px }
.form-control { width:100%;padding:8px 12px;border:1px solid var(--gray-300);border-radius:6px;font-size:13px;outline:none;transition:border-color .2s }
.form-control:focus { border-color:var(--primary);box-shadow:0 0 0 3px rgba(37,99,235,.1) }
input.form-control, select.form-control { height:35px }
select.form-control { appearance:none;background:#fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E") no-repeat right 10px center }

/* 提示消息 */
.flashes { margin-bottom:16px }
.flash { padding:10px 16px;border-radius:6px;font-size:13px;margin-bottom:8px }
.flash-success { background:#dcfce7;color:var(--success);border:1px solid #bbf7d0 }
.flash-error { background:#fee2e2;color:var(--danger);border:1px solid #fecaca }
.flash-warning { background:#fef3c7;color:var(--warning);border:1px solid #fde68a }
.flash-info { background:#dbeafe;color:var(--primary);border:1px solid #bfdbfe }

/* 分页 */
.pagination { display:flex;justify-content:center;gap:4px;margin-top:20px }
.pagination a,.pagination span { display:inline-block;padding:6px 12px;border-radius:4px;font-size:13px;text-decoration:none;border:1px solid var(--gray-200);color:var(--gray-600) }
.pagination a:hover { background:var(--gray-50) }
.pagination .current { background:var(--primary);color:#fff;border-color:var(--primary) }
.pagination .disabled { color:var(--gray-300);pointer-events:none }

/* 弹窗/模态 */
.modal-overlay { display:none;position:fixed;inset:0;background:rgba(0,0,0,.4);z-index:1000;align-items:center;justify-content:center }
.modal-overlay.show { display:flex }
.modal { background:#fff;border-radius:12px;width:90%;max-width:500px;max-height:80vh;overflow-y:auto;box-shadow:0 20px 60px rgba(0,0,0,.15) }
.modal-header { padding:16px 20px;border-bottom:1px solid var(--gray-200);display:flex;align-items:center;justify-content:space-between;font-weight:600 }
.modal-body { padding:20px }
.modal-close { background:none;border:none;font-size:20px;cursor:pointer;color:var(--gray-400) }

/* 登录页 */
.login-page { display:flex;min-height:100vh;align-items:center;justify-content:center;background:linear-gradient(135deg,#1e293b 0%,#334155 100%) }
.login-box { background:#fff;border-radius:12px;padding:40px;width:380px;box-shadow:0 20px 60px rgba(0,0,0,.2) }
.login-box h1 { font-size:22px;text-align:center;margin-bottom:6px }
.login-box .login-sub { text-align:center;color:var(--gray-500);font-size:13px;margin-bottom:28px }
.login-box .btn { width:100%;justify-content:center;padding:10px }

/* 工具类 */
.flex { display:flex }
.items-center { align-items:center }
.justify-between { justify-content:space-between }
.gap-2 { gap:8px }
.gap-4 { gap:16px }
.mt-4 { margin-top:16px }
.mb-4 { margin-bottom:16px }
.text-sm { font-size:13px }
.text-center { text-align:center }
.text-right { text-align:right }
.text-muted { color:var(--gray-500) }
.w-full { width:100% }
.ml-auto { margin-left:auto }

/* 勾选状态条（跨页累计） */
.sel-bar { background:var(--gray-100);padding:10px 16px;border-radius:8px;margin-bottom:12px;gap:14px }

/* checkbox styling */
.checkbox-cell { width:40px }

/* grid for forms */
.form-grid { display:grid;grid-template-columns:1fr 1fr;gap:16px }
.form-row { display:flex;gap:16px }
.form-divider { border-top:1px solid var(--gray-200);padding-top:12px;margin-top:4px;font-size:13px;color:var(--gray-500);font-weight:600 }
.flex-1 { flex:1 }
@media (max-width:640px) { .form-grid { grid-template-columns:1fr } .form-row { flex-direction:column;gap:0 } }

/* 响应式 */
.menu-toggle { display:none;background:none;border:1px solid var(--gray-300);border-radius:6px;padding:5px 9px;cursor:pointer;color:var(--gray-600);align-items:center;justify-content:center }
.mobile-menu { display:none;position:fixed;top:56px;left:0;right:0;background:#fff;box-shadow:0 4px 16px rgba(0,0,0,.12);z-index:200;border-bottom:1px solid var(--gray-200);max-height:calc(100vh - 56px);overflow-y:auto }
.mobile-menu.show { display:block }
.mobile-menu-nav a { display:block;padding:12px 20px;font-size:14px;color:var(--gray-700);text-decoration:none;border-bottom:1px solid var(--gray-100) }
.mobile-menu-nav a.active { background:var(--gray-100);color:var(--primary);font-weight:600 }
.mobile-menu-user { padding:14px 20px;font-size:13px;color:var(--gray-500) }
.mobile-menu-user strong { display:block;color:var(--gray-800);margin-bottom:8px }
.mobile-menu-user .logout-link { display:inline-block;color:var(--danger);font-weight:600;text-decoration:none }
@media (max-width:768px) {
    .sidebar { display:none }
    .content { padding:16px }
    .stats-grid { grid-template-columns:1fr 1fr }
    .menu-toggle { display:inline-flex }
}