:root{--primary-color: #2563eb;--primary-hover: #1d4ed8;--primary-active: #1e40af;--primary-bg: #eff6ff;--primary-border: #bfdbfe;--primary-gradient: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);--primary-shadow: 0 4px 14px 0 rgba(37, 99, 235, .28);--accent-color: #f97316;--accent-hover: #ea580c;--accent-active: #c2410c;--accent-bg: #fff7ed;--accent-border: #fed7aa;--accent-gradient: linear-gradient(135deg, #fb923c 0%, #ea580c 100%);--secondary-color: #6366f1;--secondary-light: #e0e7ff;--success-color: #10b981;--success-bg: #ecfdf5;--success-border: #a7f3d0;--warning-color: #f59e0b;--warning-bg: #fef3c7;--warning-border: #fde68a;--error-color: #ef4444;--error-bg: #fef2f2;--error-border: #fecaca;--info-color: #2563eb;--info-bg: #eff6ff;--info-border: #bfdbfe;--text-primary: #0f172a;--text-secondary: #475569;--text-muted: #94a3b8;--text-disabled: #cbd5e1;--text-white: #ffffff;--bg-page: #f8fafc;--bg-card: #ffffff;--bg-sidebar: #ffffff;--bg-hover: #f1f5f9;--bg-selected: #eff6ff;--bg-secondary: #f8fafc;--bg-tertiary: #f1f5f9;--bg-component: #ffffff;--border-color: #e2e8f0;--border-light: #f1f5f9;--border-focus: #3b82f6;--radius-xs: 4px;--radius-sm: 8px;--radius-md: 10px;--radius-lg: 14px;--radius-xl: 18px;--radius-full: 9999px;--shadow-color: rgba(15, 23, 42, .06);--shadow-xs: 0 1px 2px 0 rgba(15, 23, 42, .05);--shadow-sm: 0 1px 3px 0 rgba(15, 23, 42, .08), 0 1px 2px -1px rgba(15, 23, 42, .08);--shadow-md: 0 4px 6px -1px rgba(15, 23, 42, .08), 0 2px 4px -2px rgba(15, 23, 42, .06);--shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, .08), 0 4px 6px -4px rgba(15, 23, 42, .04);--shadow-xl: 0 20px 25px -5px rgba(15, 23, 42, .1), 0 8px 10px -6px rgba(15, 23, 42, .05);--shadow-card: 0 1px 3px 0 rgba(15, 23, 42, .05), 0 1px 2px -1px rgba(15, 23, 42, .05);--shadow-card-hover: 0 12px 24px -4px rgba(15, 23, 42, .09), 0 4px 6px -2px rgba(15, 23, 42, .04);--shadow-modal: 0 25px 50px -12px rgba(15, 23, 42, .25);--box-shadow: var(--shadow-md);--box-shadow-hover: var(--shadow-lg);--modal-shadow: var(--shadow-modal);--header-height: 64px;--sidebar-width: 260px;--transition-fast: .15s cubic-bezier(.4, 0, .2, 1);--transition-normal: .22s cubic-bezier(.4, 0, .2, 1);--transition-slow: .35s cubic-bezier(.4, 0, .2, 1)}*,*:before,*:after{box-sizing:border-box}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,PingFang SC,Hiragino Sans GB,Microsoft YaHei,Noto Sans SC,sans-serif;background-color:var(--bg-page);color:var(--text-primary);line-height:1.6;font-size:14px;overflow-x:hidden;overflow-y:auto;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}html{-webkit-text-size-adjust:100%}a{color:var(--primary-color);text-decoration:none;transition:color var(--transition-fast);cursor:pointer}a:hover{color:var(--primary-hover)}h1,h2,h3,h4,h5,h6{margin-top:0;margin-bottom:.5em;color:var(--text-primary);font-weight:600;letter-spacing:-.01em}::-webkit-scrollbar{width:6px;height:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#cbd5e1;border-radius:9999px;transition:background var(--transition-fast)}::-webkit-scrollbar-thumb:hover{background:#94a3b8}button,.button,.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;font-weight:500;white-space:nowrap;text-align:center;border:1.2px solid var(--border-color);cursor:pointer;transition:all var(--transition-normal);user-select:none;-webkit-user-select:none;touch-action:manipulation;height:36px;padding:0 16px;font-size:13.5px;border-radius:var(--radius-md);background:#fff;color:var(--text-primary);box-shadow:0 1px 2px #0f172a0a;font-family:inherit;outline:none}button:hover,button:focus-visible,.button:hover,.btn:hover{background:#f8fafc;border-color:#93c5fd;color:#1d4ed8;box-shadow:0 2px 8px #2563eb14;transform:translateY(-1px)}button:active,.button:active,.btn:active{background:#f1f5f9;border-color:#60a5fa;transform:translateY(0)}button.primary,button.solid,.btn-primary{background:var(--primary-gradient);color:#fff;border-color:transparent;box-shadow:0 2px 6px #2563eb38}button.primary:hover,button.solid:hover,.btn-primary:hover{background:linear-gradient(135deg,#2563eb,#1d4ed8);color:#fff;box-shadow:0 4px 12px #2563eb4d}button:disabled{color:var(--text-disabled);background:#e2e8f0;border-color:transparent;box-shadow:none;cursor:not-allowed;transform:none}button.secondary{color:#334155;background:#fff;border:1.5px solid var(--border-color);box-shadow:0 1px 2px #0f172a0a}button.secondary:hover{color:var(--text-primary);background:#f8fafc;border-color:#cbd5e1;box-shadow:0 2px 6px #0f172a0f}button.danger{color:#fff;background:linear-gradient(135deg,#ef4444,#dc2626);box-shadow:0 2px 6px #ef444438}button.danger:hover{background:linear-gradient(135deg,#dc2626,#b91c1c);box-shadow:0 4px 12px #ef444452}button.accent,.btn-accent{background:var(--accent-gradient);color:#fff;box-shadow:0 2px 8px #f9731640}button.accent:hover,.btn-accent:hover{background:linear-gradient(135deg,#ea580c,#c2410c);box-shadow:0 4px 14px #f9731659}button.text-btn{background:transparent;border:none;box-shadow:none;color:var(--primary-color);padding:0 12px;height:auto}button.text-btn:hover{color:var(--primary-hover);background:var(--primary-bg);border-radius:var(--radius-sm);transform:none}input[type=text],input[type=password],input[type=email],input[type=number],select,textarea{box-sizing:border-box;margin:0;display:inline-block;width:100%;min-width:0;padding:9px 14px;color:var(--text-primary);font-size:14px;line-height:1.5;background:#fff;border:1.5px solid var(--border-color);border-radius:var(--radius-md);transition:border-color var(--transition-fast),box-shadow var(--transition-fast),background-color var(--transition-fast);font-family:inherit;outline:none}input[type=text]:focus,input[type=password]:focus,input[type=email]:focus,input[type=number]:focus,select:focus,textarea:focus{background:#fff;border-color:var(--border-focus);box-shadow:0 0 0 3px #3b82f626}input[type=text]::placeholder,input[type=password]::placeholder,input[type=email]::placeholder,input[type=number]::placeholder,textarea::placeholder{color:var(--text-muted)}.card{box-sizing:border-box;margin:0 0 20px;padding:22px 26px;color:var(--text-primary);font-size:14px;background:var(--bg-card);border-radius:var(--radius-lg);box-shadow:var(--shadow-card);border:1px solid rgba(226,232,240,.85);transition:box-shadow var(--transition-normal),transform var(--transition-normal),border-color var(--transition-normal)}.card:hover{box-shadow:var(--shadow-card-hover);transform:translateY(-2px);border-color:#cbd5e1}table{width:100%;text-align:left;border-collapse:separate;border-spacing:0;overflow:hidden;border:1px solid var(--border-color);border-radius:var(--radius-lg);background:#fff}thead tr th{background:#f8fafc;color:var(--text-secondary);font-weight:600;font-size:12px;text-align:left;border-bottom:1px solid var(--border-color);padding:13px 18px;text-transform:uppercase;letter-spacing:.05em}tbody tr td{padding:14px 18px;border-bottom:1px solid var(--border-light);background:#fff;transition:background var(--transition-fast);color:var(--text-primary)}tbody tr:last-child td{border-bottom:none}tbody tr:hover td{background:#f8fafc}.tag{box-sizing:border-box;margin:0 6px 0 0;font-size:12px;line-height:1.4;display:inline-flex;align-items:center;gap:4px;height:auto;padding:3px 10px;white-space:nowrap;background:var(--bg-tertiary);border:1px solid var(--border-color);border-radius:var(--radius-full);transition:all var(--transition-fast);font-weight:600}.tag-blue{background:#eff6ff;border-color:#bfdbfe;color:#1d4ed8}.tag-green{background:#ecfdf5;border-color:#a7f3d0;color:#047857}.tag-red{background:#fef2f2;border-color:#fecaca;color:#b91c1c}.tag-orange{background:#fff7ed;border-color:#fed7aa;color:#c2410c}.tag-purple{background:#faf5ff;border-color:#e9d5ff;color:#7e22ce}.tag-gray{background:#f1f5f9;border-color:#e2e8f0;color:#475569}.toast-host{position:fixed;top:18px;left:50%;transform:translate(-50%);z-index:9999;display:flex;flex-direction:column;gap:10px;width:min(520px,calc(100vw - 24px));pointer-events:none}.toast{pointer-events:none;padding:12px 18px;border-radius:var(--radius-lg);box-shadow:0 10px 25px -5px #0f172a1f,0 8px 10px -6px #0f172a0a;font-weight:600;color:var(--text-primary);background:#fffffff5;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border:1px solid var(--border-color);animation:toast-in .22s ease-out,toast-out .28s ease-in calc(var(--toast-duration, 3.2s) - .28s)}.toast:after{content:;display:block;height:3px;margin-top:10px;border-radius:var(--radius-full);background:linear-gradient(90deg,var(--primary-color) 0%,var(--accent-color) 100%);transform-origin:left;animation:toast-bar var(--toast-duration, 3.2s) linear forwards}.toast-error{border-color:var(--error-border)}.toast-error:after{background:linear-gradient(90deg,var(--error-color) 0%,var(--warning-color) 100%)}.toast-success{border-color:var(--success-border)}.toast-success:after{background:linear-gradient(90deg,var(--success-color) 0%,var(--primary-color) 100%)}@keyframes toast-in{0%{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}@keyframes toast-out{0%{opacity:1;transform:translateY(0);filter:blur(0)}to{opacity:0;transform:translateY(-8px);filter:blur(2px)}}@keyframes toast-bar{0%{transform:scaleX(1)}to{transform:scaleX(0)}}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background-color:#0f172a73;backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);display:flex;align-items:center;justify-content:center;z-index:1000;animation:modalFadeIn .2s ease-out}.modal-content{background:#fff;border-radius:var(--radius-xl);box-shadow:var(--modal-shadow);display:flex;flex-direction:column;max-height:90vh;overflow:hidden;border:1px solid rgba(255,255,255,.8);animation:modalScaleIn .22s cubic-bezier(.16,1,.3,1)}@keyframes modalFadeIn{0%{opacity:0}to{opacity:1}}@keyframes modalScaleIn{0%{opacity:0;transform:scale(.96) translateY(8px)}to{opacity:1;transform:scale(1) translateY(0)}}.modal-header{padding:18px 24px;border-bottom:1px solid var(--border-light);display:flex;justify-content:space-between;align-items:center;font-weight:700;font-size:16px;color:var(--text-primary);background:#f8fafc}.modal-body{padding:24px;overflow-y:auto}.modal-footer{padding:16px 24px;border-top:1px solid var(--border-light);text-align:right;background:#f8fafc}.app-layout{display:flex;min-height:100vh;background:var(--bg-page)}.sidebar{width:var(--sidebar-width);background:var(--bg-card);color:var(--text-primary);display:flex;flex-direction:column;position:fixed;left:0;top:0;bottom:0;z-index:100;border-right:1px solid var(--border-color);min-width:var(--sidebar-width);max-width:400px;transition:width var(--transition-normal)}.sidebar-header{height:64px;display:flex;align-items:center;justify-content:flex-start;gap:12px;background:#fff;color:var(--text-primary);font-weight:700;font-size:18px;overflow:hidden;border-bottom:1px solid var(--border-light);padding:0 20px;letter-spacing:-.01em}.sidebar-header img{height:38px;object-fit:contain}.sidebar-menu{flex:1;padding:14px 10px;overflow-y:auto}.menu-item{display:flex;align-items:center;gap:12px;padding:10px 14px;height:auto;cursor:pointer;transition:all var(--transition-fast);color:var(--text-secondary);margin-bottom:4px;font-size:14px;font-weight:500;border-radius:var(--radius-md);background:transparent;border:1px solid transparent;position:relative;text-decoration:none}.menu-item:hover{background:#f1f5f9;color:var(--primary-color);transform:translate(2px)}.menu-item.active{background:var(--primary-bg);color:var(--primary-color);font-weight:600;border-color:var(--primary-border)}.menu-item:before{content:"";position:absolute;left:0;top:50%;transform:translateY(-50%);width:3px;height:0;background:var(--primary-gradient);border-radius:0 2px 2px 0;transition:height var(--transition-fast)}.menu-item:hover:before{height:18px}.menu-item.active:before{height:24px}.sidebar-footer{padding:14px;border-top:1px solid var(--border-light);background:#fff}.sidebar-resize-handle{position:absolute;right:-3px;top:0;bottom:0;width:6px;cursor:ew-resize;z-index:101;display:flex;align-items:center;justify-content:center;transition:background var(--transition-fast)}.sidebar-resize-handle:hover,.sidebar-resize-handle.dragging{background:#2563eb33}.sidebar-resize-handle:after{content:"";width:2px;height:40px;background:var(--border-color);border-radius:1px}.sidebar-resize-handle:hover:after,.sidebar-resize-handle.dragging:after{background:var(--primary-color)}.main-content{margin-left:var(--sidebar-width);flex:1;padding:0;min-height:100vh;transition:margin-left var(--transition-normal);background:var(--bg-page)}.main-content>div,.teacher-main>div{padding:0}.student-topbar,.admin-topbar{background:#ffffffeb;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid #e2e8f0;padding:0 20px;height:48px;display:flex;align-items:center;justify-content:space-between;gap:16px;position:sticky;top:0;z-index:25;box-shadow:0 1px 2px #0f172a0a}.topbar-context{display:flex;align-items:center;gap:8px;font-size:13px;flex:1;min-width:0}.topbar-portal-badge{font-size:11px;font-weight:700;padding:2px 7px;border-radius:6px;letter-spacing:.02em;display:inline-flex;align-items:center;flex-shrink:0}.topbar-portal-badge.teacher{background:#eff6ff;color:#2563eb;border:1px solid #bfdbfe}.topbar-portal-badge.student{background:#ecfdf5;color:#059669;border:1px solid #a7f3d0}.topbar-portal-badge.admin{background:#eef2ff;color:#4f46e5;border:1px solid #c7d2fe}.topbar-crumb-sep{color:#cbd5e1;font-size:12px;flex-shrink:0}.topbar-crumb-title{font-weight:700;font-size:14px;color:#0f172a;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.admin-topbar-right,.student-topbar-right{display:flex;align-items:center;justify-content:flex-end}.teacher-page-body,.student-page-body,.admin-page-body{padding:14px 20px 32px}.page-header-simple{padding:0;margin-bottom:12px;background:transparent;border:none;box-shadow:none;display:flex;align-items:center;justify-content:space-between;gap:12px}.page-title{font-size:16px;font-weight:700;color:var(--text-primary);line-height:1.4;margin:0}.page-subtitle{display:none}.admin-page-body h2{font-size:16px;font-weight:700;color:#0f172a;margin:0 0 10px;line-height:1.4}.flex{display:flex}.flex-col{flex-direction:column}.items-center{align-items:center}.justify-between{justify-content:space-between}.justify-center{justify-content:center}.justify-end{justify-content:flex-end}.gap-2{gap:8px}.gap-4{gap:16px}.gap-6{gap:24px}.gap-8{gap:32px}.p-4{padding:16px}.p-6{padding:24px}.mb-2{margin-bottom:8px}.mb-4{margin-bottom:16px}.mr-2{margin-right:8px}.mr-4{margin-right:16px}.w-full{width:100%}.h-full{height:100%}.text-center{text-align:center}.text-right{text-align:right}.font-bold{font-weight:600}.text-lg{font-size:16px}.text-xl{font-size:20px}.text-gray{color:var(--text-secondary)}.rounded-full{border-radius:9999px}.relative{position:relative}.absolute{position:absolute}.bottom-0{bottom:0}