/* 本地工具类样式表 (类 Tailwind 语法，纯本地零依赖) */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;font-size:14px;line-height:1.6;color:#1f2937;background:#f3f4f6;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
img,video{max-width:100%;display:block}
button{cursor:pointer;font-family:inherit;border:none;background:none}
input,select,textarea{font-family:inherit;font-size:inherit;outline:none}
ul,ol{list-style:none}
table{border-collapse:collapse;width:100%}
.block{display:block}.inline-block{display:inline-block}.inline{display:inline}
.flex{display:flex}.inline-flex{display:inline-flex}.grid{display:grid}.hidden{display:none !important}
.group:hover .group-hover\:block{display:block !important}
.flex-col{flex-direction:column}.flex-row{flex-direction:row}.flex-wrap{flex-wrap:wrap}
.items-center{align-items:center}.items-start{align-items:flex-start}.items-end{align-items:flex-end}.items-stretch{align-items:stretch}
.justify-center{justify-content:center}.justify-between{justify-content:space-between}.justify-start{justify-content:flex-start}.justify-end{justify-content:flex-end}.justify-around{justify-content:space-around}
.flex-1{flex:1 1 0%}.flex-shrink-0{flex-shrink:0}.flex-grow{flex-grow:1}
.gap-1{gap:.25rem}.gap-2{gap:.5rem}.gap-3{gap:.75rem}.gap-4{gap:1rem}.gap-6{gap:1.5rem}.gap-8{gap:2rem}
.grid-cols-1{grid-template-columns:repeat(1,minmax(0,1fr))}
.grid-cols-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-cols-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-cols-4{grid-template-columns:repeat(4,minmax(0,1fr))}
.col-span-2{grid-column:span 2/span 2}.col-span-3{grid-column:span 3/span 3}
.relative{position:relative}.absolute{position:absolute}.fixed{position:fixed}.sticky{position:sticky}
.top-0{top:0}.left-0{left:0}.right-0{right:0}.bottom-0{bottom:0}.inset-0{top:0;right:0;bottom:0;left:0}
.z-10{z-index:10}.z-20{z-index:20}.z-50{z-index:50}
.w-full{width:100%}.w-auto{width:auto}.w-10{width:2.5rem}.w-12{width:3rem}.w-16{width:4rem}.w-20{width:5rem}.w-24{width:6rem}.w-32{width:8rem}.w-40{width:10rem}.w-48{width:12rem}.w-56{width:14rem}.w-64{width:16rem}.w-72{width:18rem}.w-80{width:20rem}
.h-full{height:100%}.h-auto{height:auto}.h-10{height:2.5rem}.h-12{height:3rem}.h-16{height:4rem}.h-20{height:5rem}.h-24{height:6rem}.h-32{height:8rem}.h-40{height:10rem}.h-48{height:12rem}.h-64{height:16rem}.h-96{height:24rem}
.max-w-full{max-width:100%}.max-w-screen-lg{max-width:1024px}.max-w-screen-xl{max-width:1280px}.max-w-screen-md{max-width:768px}.max-w-2xl{max-width:42rem}.max-w-3xl{max-width:48rem}.max-w-4xl{max-width:56rem}
.min-h-screen{min-height:100vh}.h-screen{height:100vh}
.m-0{margin:0}.m-1{margin:.25rem}.m-2{margin:.5rem}.m-3{margin:.75rem}.m-4{margin:1rem}
.mx-auto{margin-left:auto;margin-right:auto}
.mt-1{margin-top:.25rem}.mt-2{margin-top:.5rem}.mt-3{margin-top:.75rem}.mt-4{margin-top:1rem}.mt-5{margin-top:1.25rem}.mt-6{margin-top:1.5rem}.mt-8{margin-top:2rem}.mt-10{margin-top:2.5rem}.mt-12{margin-top:3rem}
.mb-1{margin-bottom:.25rem}.mb-2{margin-bottom:.5rem}.mb-3{margin-bottom:.75rem}.mb-4{margin-bottom:1rem}.mb-5{margin-bottom:1.25rem}.mb-6{margin-bottom:1.5rem}.mb-8{margin-bottom:2rem}.mb-10{margin-bottom:2.5rem}
.ml-1{margin-left:.25rem}.ml-2{margin-left:.5rem}.ml-3{margin-left:.75rem}.ml-4{margin-left:1rem}
.mr-1{margin-right:.25rem}.mr-2{margin-right:.5rem}.mr-3{margin-right:.75rem}.mr-4{margin-right:1rem}
.my-2{margin-top:.5rem;margin-bottom:.5rem}.my-3{margin-top:.75rem;margin-bottom:.75rem}.my-4{margin-top:1rem;margin-bottom:1rem}.my-6{margin-top:1.5rem;margin-bottom:1.5rem}
.mx-2{margin-left:.5rem;margin-right:.5rem}.mx-4{margin-left:1rem;margin-right:1rem}
.p-0{padding:0}.p-1{padding:.25rem}.p-2{padding:.5rem}.p-3{padding:.75rem}.p-4{padding:1rem}.p-5{padding:1.25rem}.p-6{padding:1.5rem}.p-8{padding:2rem}
.px-2{padding-left:.5rem;padding-right:.5rem}.px-3{padding-left:.75rem;padding-right:.75rem}.px-4{padding-left:1rem;padding-right:1rem}.px-5{padding-left:1.25rem;padding-right:1.25rem}.px-6{padding-left:1.5rem;padding-right:1.5rem}.px-8{padding-left:2rem;padding-right:2rem}
.py-1{padding-top:.25rem;padding-bottom:.25rem}.py-2{padding-top:.5rem;padding-bottom:.5rem}.py-3{padding-top:.75rem;padding-bottom:.75rem}.py-4{padding-top:1rem;padding-bottom:1rem}.py-5{padding-top:1.25rem;padding-bottom:1.25rem}.py-6{padding-top:1.5rem;padding-bottom:1.5rem}.py-8{padding-top:2rem;padding-bottom:2rem}.py-10{padding-top:2.5rem;padding-bottom:2.5rem}
.pt-2{padding-top:.5rem}.pt-4{padding-top:1rem}.pt-6{padding-top:1.5rem}.pb-4{padding-bottom:1rem}.pb-6{padding-bottom:1.5rem}.pl-3{padding-left:.75rem}.pl-4{padding-left:1rem}.pl-6{padding-left:1.5rem}.pr-4{padding-right:1rem}
.text-left{text-align:left}.text-center{text-align:center}.text-right{text-align:right}
.text-xs{font-size:.75rem;line-height:1rem}.text-sm{font-size:.875rem;line-height:1.25rem}.text-base{font-size:1rem;line-height:1.5rem}.text-lg{font-size:1.125rem;line-height:1.75rem}.text-xl{font-size:1.25rem;line-height:1.75rem}.text-2xl{font-size:1.5rem;line-height:2rem}.text-3xl{font-size:1.875rem;line-height:2.25rem}.text-4xl{font-size:2.25rem;line-height:2.5rem}
.font-thin{font-weight:100}.font-light{font-weight:300}.font-normal{font-weight:400}.font-medium{font-weight:500}.font-semibold{font-weight:600}.font-bold{font-weight:700}.font-extrabold{font-weight:800}
.leading-none{line-height:1}.leading-tight{line-height:1.25}.leading-snug{line-height:1.375}.leading-normal{line-height:1.5}.leading-relaxed{line-height:1.625}.leading-loose{line-height:2}
.tracking-wide{letter-spacing:.025em}.tracking-wider{letter-spacing:.05em}
.uppercase{text-transform:uppercase}.lowercase{text-transform:lowercase}.capitalize{text-transform:capitalize}
.underline{text-decoration:underline}.line-through{text-decoration:line-through}.no-underline{text-decoration:none}
.truncate{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.break-all{word-break:break-all}.break-words{overflow-wrap:break-word}
.whitespace-nowrap{white-space:nowrap}
.text-white{color:#fff}.text-black{color:#000}
.text-gray-50{color:#f9fafb}.text-gray-100{color:#f3f4f6}.text-gray-200{color:#e5e7eb}.text-gray-300{color:#d1d5db}.text-gray-400{color:#9ca3af}.text-gray-500{color:#6b7280}.text-gray-600{color:#4b5563}.text-gray-700{color:#374151}.text-gray-800{color:#1f2937}.text-gray-900{color:#111827}
.text-red-50{color:#fef2f2}.text-red-100{color:#fee2e2}.text-red-400{color:#f87171}.text-red-500{color:#ef4444}.text-red-600{color:#dc2626}.text-red-700{color:#b91c1c}
.text-orange-500{color:#f97316}.text-orange-600{color:#ea580c}
.text-yellow-500{color:#eab308}.text-yellow-600{color:#ca8a04}
.text-green-50{color:#f0fdf4}.text-green-100{color:#dcfce7}.text-green-400{color:#4ade80}.text-green-500{color:#22c55e}.text-green-600{color:#16a34a}.text-green-700{color:#15803d}
.text-blue-50{color:#eff6ff}.text-blue-100{color:#dbeafe}.text-blue-400{color:#60a5fa}.text-blue-500{color:#3b82f6}.text-blue-600{color:#2563eb}.text-blue-700{color:#1d4ed8}
.text-indigo-500{color:#6366f1}.text-indigo-600{color:#4f46e5}
.text-purple-500{color:#a855f7}.text-purple-600{color:#9333ea}
.text-pink-500{color:#ec4899}.text-cyan-500{color:#06b6d4}
.bg-white{background:#fff}.bg-black{background:#000}.bg-transparent{background:transparent}
.bg-gray-50{background:#f9fafb}.bg-gray-100{background:#f3f4f6}.bg-gray-200{background:#e5e7eb}.bg-gray-300{background:#d1d5db}.bg-gray-700{background:#374151}.bg-gray-800{background:#1f2937}.bg-gray-900{background:#111827}
.bg-red-50{background:#fef2f2}.bg-red-100{background:#fee2e2}.bg-red-500{background:#ef4444}.bg-red-600{background:#dc2626}
.bg-orange-50{background:#fff7ed}.bg-orange-100{background:#ffedd5}.bg-orange-500{background:#f97316}
.bg-yellow-50{background:#fefce8}.bg-yellow-100{background:#fef9c3}.bg-yellow-400{background:#facc15}.bg-yellow-500{background:#eab308}
.bg-green-50{background:#f0fdf4}.bg-green-100{background:#dcfce7}.bg-green-500{background:#22c55e}.bg-green-600{background:#16a34a}
.bg-blue-50{background:#eff6ff}.bg-blue-100{background:#dbeafe}.bg-blue-500{background:#3b82f6}.bg-blue-600{background:#2563eb}.bg-blue-700{background:#1d4ed8}
.bg-indigo-50{background:#eef2ff}.bg-indigo-100{background:#e0e7ff}.bg-indigo-500{background:#6366f1}.bg-indigo-600{background:#4f46e5}
.bg-purple-50{background:#faf5ff}.bg-purple-100{background:#f3e8ff}.bg-purple-500{background:#a855f7}
.bg-pink-50{background:#fdf2f8}.bg-pink-500{background:#ec4899}.bg-cyan-50{background:#ecfeff}.bg-cyan-500{background:#06b6d4}
.border{border:1px solid #e5e7eb}.border-0{border:0}.border-2{border-width:2px}
.border-t{border-top:1px solid #e5e7eb}.border-b{border-bottom:1px solid #e5e7eb}.border-l{border-left:1px solid #e5e7eb}.border-r{border-right:1px solid #e5e7eb}
.border-gray-100{border-color:#f3f4f6}.border-gray-200{border-color:#e5e7eb}.border-gray-300{border-color:#d1d5db}.border-gray-400{border-color:#9ca3af}
.border-red-300{border-color:#fca5a5}.border-red-500{border-color:#ef4444}
.border-green-300{border-color:#86efac}.border-green-500{border-color:#22c55e}
.border-blue-300{border-color:#93c5fd}.border-blue-500{border-color:#3b82f6}
.border-yellow-300{border-color:#fde047}.border-indigo-300{border-color:#a5b4fc}
.rounded{border-radius:.25rem}.rounded-sm{border-radius:.125rem}.rounded-md{border-radius:.375rem}.rounded-lg{border-radius:.5rem}.rounded-xl{border-radius:.75rem}.rounded-2xl{border-radius:1rem}.rounded-full{border-radius:9999px}
.rounded-t-lg{border-top-left-radius:.5rem;border-top-right-radius:.5rem}.rounded-b-lg{border-bottom-left-radius:.5rem;border-bottom-right-radius:.5rem}
.shadow-sm{box-shadow:0 1px 2px 0 rgba(0,0,0,.05)}
.shadow{box-shadow:0 1px 3px 0 rgba(0,0,0,.1),0 1px 2px -1px rgba(0,0,0,.1)}
.shadow-md{box-shadow:0 4px 6px -1px rgba(0,0,0,.1),0 2px 4px -2px rgba(0,0,0,.1)}
.shadow-lg{box-shadow:0 10px 15px -3px rgba(0,0,0,.1),0 4px 6px -4px rgba(0,0,0,.1)}
.shadow-xl{box-shadow:0 20px 25px -5px rgba(0,0,0,.1),0 8px 10px -6px rgba(0,0,0,.1)}
.shadow-inner{box-shadow:inset 0 2px 4px 0 rgba(0,0,0,.05)}.shadow-none{box-shadow:none}
.opacity-0{opacity:0}.opacity-50{opacity:.5}.opacity-75{opacity:.75}.opacity-100{opacity:1}
.visible{visibility:visible}.invisible{visibility:hidden}
.overflow-hidden{overflow:hidden}.overflow-auto{overflow:auto}.overflow-scroll{overflow:scroll}.overflow-x-auto{overflow-x:auto}.overflow-y-auto{overflow-y:auto}
.cursor-pointer{cursor:pointer}.cursor-not-allowed{cursor:not-allowed}.cursor-default{cursor:default}
.pointer-events-none{pointer-events:none}.pointer-events-auto{pointer-events:auto}.select-none{user-select:none}
.object-cover{object-fit:cover}.object-contain{object-fit:contain}.object-fill{object-fit:fill}
.transition{transition:all .15s ease}.transition-all{transition:all .15s ease}
.duration-150{transition-duration:.15s}.duration-200{transition-duration:.2s}.duration-300{transition-duration:.3s}
.scale-95{transform:scale(.95)}.scale-100{transform:scale(1)}.scale-105{transform:scale(1.05)}
.hover\:bg-gray-50:hover{background:#f9fafb}.hover\:bg-gray-100:hover{background:#f3f4f6}.hover\:bg-gray-200:hover{background:#e5e7eb}.hover\:bg-gray-700:hover{background:#374151}.hover\:bg-gray-800:hover{background:#1f2937}
.hover\:bg-red-600:hover{background:#dc2626}.hover\:bg-red-700:hover{background:#b91c1c}
.hover\:bg-blue-600:hover{background:#2563eb}.hover\:bg-blue-700:hover{background:#1d4ed8}
.hover\:bg-green-600:hover{background:#16a34a}.hover\:bg-green-700:hover{background:#15803d}
.hover\:bg-indigo-600:hover{background:#4f46e5}.hover\:bg-orange-600:hover{background:#ea580c}
.hover\:text-gray-500:hover{color:#6b7280}.hover\:text-gray-700:hover{color:#374151}.hover\:text-gray-900:hover{color:#111827}
.hover\:text-blue-600:hover{color:#2563eb}.hover\:text-blue-700:hover{color:#1d4ed8}.hover\:text-red-600:hover{color:#dc2626}.hover\:text-white:hover{color:#fff}
.hover\:underline:hover{text-decoration:underline}
.hover\:shadow-md:hover{box-shadow:0 4px 6px -1px rgba(0,0,0,.1),0 2px 4px -2px rgba(0,0,0,.1)}
.hover\:shadow-lg:hover{box-shadow:0 10px 15px -3px rgba(0,0,0,.1),0 4px 6px -4px rgba(0,0,0,.1)}
.hover\:scale-105:hover{transform:scale(1.05)}.hover\:opacity-90:hover{opacity:.9}
.focus\:outline-none:focus{outline:0}.focus\:ring-2:focus{box-shadow:0 0 0 2px rgba(59,130,246,.5)}
.focus\:border-blue-500:focus{border-color:#3b82f6}.focus\:border-indigo-500:focus{border-color:#6366f1}
.active\:scale-95:active{transform:scale(.95)}
input[type="text"],input[type="password"],input[type="email"],input[type="number"],input[type="tel"],input[type="url"],input[type="date"],input[type="time"],input[type="datetime-local"],input[type="file"],select,textarea{width:100%;padding:.5rem .75rem;border:1px solid #d1d5db;border-radius:.375rem;background:#fff;color:#1f2937;transition:border-color .15s,box-shadow .15s}
input:focus,select:focus,textarea:focus{border-color:#3b82f6;box-shadow:0 0 0 2px rgba(59,130,246,.2);outline:none}
input:disabled,select:disabled,textarea:disabled{background:#f3f4f6;cursor:not-allowed}
textarea{resize:vertical;min-height:80px}
label{display:block;font-weight:500;color:#374151;margin-bottom:.25rem}
.checkbox-label,.radio-label{display:inline-flex;align-items:center;gap:.5rem;font-weight:400;margin:0;cursor:pointer}
input[type="checkbox"],input[type="radio"]{width:auto;margin:0;accent-color:#3b82f6}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;padding:.5rem 1rem;border-radius:.375rem;font-weight:500;font-size:.875rem;transition:all .15s;cursor:pointer;border:1px solid transparent;white-space:nowrap}
.btn-sm{padding:.25rem .625rem;font-size:.75rem}.btn-lg{padding:.75rem 1.5rem;font-size:1rem}
.btn-primary{background:#3b82f6;color:#fff;border-color:#3b82f6}.btn-primary:hover{background:#2563eb;border-color:#2563eb}
.btn-indigo{background:#6366f1;color:#fff;border-color:#6366f1}.btn-indigo:hover{background:#4f46e5;border-color:#4f46e5}
.btn-green{background:#22c55e;color:#fff;border-color:#22c55e}.btn-green:hover{background:#16a34a;border-color:#16a34a}
.btn-red{background:#ef4444;color:#fff;border-color:#ef4444}.btn-red:hover{background:#dc2626;border-color:#dc2626}
.btn-orange{background:#f97316;color:#fff;border-color:#f97316}.btn-orange:hover{background:#ea580c;border-color:#ea580c}
.btn-gray{background:#fff;color:#374151;border-color:#d1d5db}.btn-gray:hover{background:#f9fafb}
.btn-dark{background:#1f2937;color:#fff;border-color:#1f2937}.btn-dark:hover{background:#111827}
.btn-warning{background:#eab308;color:#fff;border-color:#eab308}.btn-warning:hover{background:#ca8a04}
.btn:disabled,.btn-disabled{opacity:.5;cursor:not-allowed;pointer-events:none}
.badge{display:inline-flex;align-items:center;padding:.125rem .625rem;border-radius:9999px;font-size:.75rem;font-weight:500;line-height:1.5}
.badge-blue{background:#dbeafe;color:#1d4ed8}.badge-green{background:#dcfce7;color:#15803d}.badge-red{background:#fee2e2;color:#b91c1c}.badge-yellow{background:#fef9c3;color:#854d0e}.badge-gray{background:#f3f4f6;color:#4b5563}.badge-purple{background:#f3e8ff;color:#7e22ce}.badge-orange{background:#ffedd5;color:#9a3412}
.card{background:#fff;border-radius:.5rem;box-shadow:0 1px 3px 0 rgba(0,0,0,.1);border:1px solid #e5e7eb}
.card-header{padding:1rem 1.25rem;border-bottom:1px solid #e5e7eb;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:.5rem}
.card-body{padding:1.25rem}
.card-footer{padding:.75rem 1.25rem;border-top:1px solid #e5e7eb;background:#f9fafb;border-radius:0 0 .5rem .5rem}
.table{width:100%;border-collapse:collapse}
.table th{text-align:left;padding:.625rem .75rem;background:#f9fafb;font-weight:600;font-size:.8125rem;color:#4b5563;border-bottom:1px solid #e5e7eb;white-space:nowrap}
.table td{padding:.625rem .75rem;border-bottom:1px solid #f3f4f6;font-size:.875rem;color:#374151}
.table tr:hover td{background:#f9fafb}
.alert{padding:.75rem 1rem;border-radius:.375rem;margin-bottom:1rem;font-size:.875rem}
.alert-info{background:#eff6ff;color:#1d4ed8;border:1px solid #bfdbfe}.alert-success{background:#f0fdf4;color:#15803d;border:1px solid #bbf7d0}.alert-warning{background:#fffbeb;color:#92400e;border:1px solid #fde68a}.alert-danger{background:#fef2f2;color:#b91c1c;border:1px solid #fecaca}
.modal-mask{position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:100;display:flex;align-items:center;justify-content:center;padding:1rem}
.modal-box{background:#fff;border-radius:.5rem;box-shadow:0 20px 25px -5px rgba(0,0,0,.1);max-width:100%;max-height:90vh;overflow:auto;animation:modalIn .2s ease}
@keyframes modalIn{from{opacity:0;transform:scale(.95)}to{opacity:1;transform:scale(1)}}
.progress{width:100%;height:.5rem;background:#e5e7eb;border-radius:9999px;overflow:hidden}
.progress-bar{height:100%;background:#3b82f6;border-radius:9999px;transition:width .3s}
.progress-bar.green{background:#22c55e}.progress-bar.orange{background:#f97316}.progress-bar.red{background:#ef4444}
.pagination{display:flex;gap:.25rem;flex-wrap:wrap;align-items:center}
.pagination a,.pagination span{display:inline-flex;align-items:center;justify-content:center;min-width:2rem;height:2rem;padding:0 .5rem;border:1px solid #e5e7eb;border-radius:.375rem;font-size:.8125rem;color:#374151;background:#fff;transition:all .15s}
.pagination a:hover{background:#f3f4f6;border-color:#d1d5db}
.pagination .active{background:#3b82f6;color:#fff;border-color:#3b82f6}
.pagination .disabled{opacity:.5;cursor:not-allowed}
.navbar{background:#fff;border-bottom:1px solid #e5e7eb;box-shadow:0 1px 2px 0 rgba(0,0,0,.05);position:sticky;top:0;z-index:40}
.nav-link{padding:.5rem .75rem;border-radius:.375rem;color:#4b5563;font-weight:500;font-size:.875rem;transition:all .15s}
.nav-link:hover{background:#f3f4f6;color:#1f2937}
.nav-link.active{background:#eff6ff;color:#2563eb}
.sidebar{width:14rem;background:#1f2937;color:#d1d5db;min-height:100vh;flex-shrink:0}
.sidebar-brand{padding:1rem 1.25rem;font-size:1.125rem;font-weight:700;color:#fff;border-bottom:1px solid #374151;display:flex;align-items:center;gap:.5rem}
.sidebar-menu{padding:.5rem 0}
.sidebar-item{display:flex;align-items:center;gap:.625rem;padding:.625rem 1.25rem;color:#d1d5db;font-size:.875rem;transition:all .15s;border-left:3px solid transparent}
.sidebar-item:hover{background:#374151;color:#fff}
.sidebar-item.active{background:#111827;color:#fff;border-left-color:#3b82f6}
.sidebar-group-title{padding:.5rem 1.25rem;font-size:.7rem;text-transform:uppercase;letter-spacing:.05em;color:#6b7280;font-weight:600}
.video-wrap{position:relative;width:100% !important;max-width:100%;background:#000;border-radius:.5rem;overflow:hidden}
.video-wrap video{width:100% !important;max-width:100%;height:auto !important;display:block;background:#000}
.video-popup{position:absolute;inset:0;background:rgba(0,0,0,.88);display:flex;align-items:center;justify-content:center;padding:1.5rem;z-index:10}
.course-card{background:#fff;border-radius:.5rem;overflow:hidden;box-shadow:0 1px 3px 0 rgba(0,0,0,.1);transition:all .2s;border:1px solid #e5e7eb}
.course-card:hover{box-shadow:0 10px 15px -3px rgba(0,0,0,.1);transform:translateY(-2px)}
.course-cover{height:10rem;background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);display:flex;align-items:center;justify-content:center;color:#fff;font-size:2rem;font-weight:700;position:relative;overflow:hidden}
.course-cover img{width:100%;height:100%;object-fit:cover}
.lesson-item{display:flex;align-items:center;gap:.75rem;padding:.625rem .75rem;border-radius:.375rem;cursor:pointer;transition:all .15s;border:1px solid transparent}
.lesson-item:hover{background:#f9fafb}
.lesson-item.active{background:#eff6ff;border-color:#bfdbfe}
.lesson-item.completed .lesson-icon{background:#dcfce7;color:#15803d}
.lesson-icon{width:1.75rem;height:1.75rem;border-radius:9999px;background:#f3f4f6;color:#6b7280;display:flex;align-items:center;justify-content:center;font-size:.75rem;font-weight:600;flex-shrink:0}
.stat-card{background:#fff;border-radius:.5rem;padding:1.25rem;border:1px solid #e5e7eb;box-shadow:0 1px 2px 0 rgba(0,0,0,.05)}
.stat-value{font-size:1.875rem;font-weight:700;color:#1f2937;line-height:1}
.stat-label{font-size:.8125rem;color:#6b7280;margin-top:.375rem}
.empty{text-align:center;padding:3rem 1rem;color:#9ca3af}
.empty-icon{font-size:3rem;margin-bottom:.75rem;opacity:.5}
@media (min-width:640px){.sm\:flex{display:flex}.sm\:hidden{display:none}.sm\:block{display:block}.sm\:grid-cols-2{grid-template-columns:repeat(2,minmax(0,1fr))}.sm\:w-auto{width:auto}}
@media (min-width:768px){.md\:flex{display:flex}.md\:hidden{display:none}.md\:block{display:block}.md\:grid-cols-2{grid-template-columns:repeat(2,minmax(0,1fr))}.md\:grid-cols-3{grid-template-columns:repeat(3,minmax(0,1fr))}.md\:grid-cols-4{grid-template-columns:repeat(4,minmax(0,1fr))}.md\:flex-row{flex-direction:row}.md\:w-64{width:16rem}}
@media (min-width:1024px){.lg\:flex{display:flex}.lg\:hidden{display:none}.lg\:grid-cols-2{grid-template-columns:repeat(2,minmax(0,1fr))}.lg\:grid-cols-3{grid-template-columns:repeat(3,minmax(0,1fr))}.lg\:grid-cols-4{grid-template-columns:repeat(4,minmax(0,1fr))}.lg\:col-span-1{grid-column:span 1/span 1}.lg\:col-span-2{grid-column:span 2/span 2}.lg\:col-span-3{grid-column:span 3/span 3}.lg\:col-span-4{grid-column:span 4/span 4}.lg\:w-72{width:18rem}}
@media print{.no-print{display:none!important}body{background:#fff}}

/* page title one line */
h2.text-lg.font-semibold{white-space:nowrap}