:root{--bg-color: #f7f8f9;--panel-bg: #ffffff;--text-main: #1f2328;--text-muted: #656d76;--border-color: #e5e7eb;--primary-color: #2563eb;--primary-hover: #1d4ed8;--success-color: #10b981;--success-hover: #059669;--danger-color: #ef4444;--warning-color: #f59e0b;--radius: 8px;--font-family: "Inter", system-ui, -apple-system, sans-serif;--shadow: 0 1px 3px rgba(0, 0, 0, .05)}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-family);background-color:var(--bg-color);color:var(--text-main);line-height:1.6}a{color:var(--primary-color);text-decoration:none;transition:color .2s}a:hover{color:var(--primary-hover)}button{cursor:pointer;font-family:inherit;border:none;border-radius:var(--radius);padding:.5rem 1.2rem;font-weight:500;font-size:.95rem;transition:all .2s}button:active{transform:scale(.98)}.btn-primary{background-color:var(--primary-color);color:#fff}.btn-primary:hover{background-color:var(--primary-hover)}.btn-success{background-color:var(--success-color);color:#fff}.btn-success:hover{background-color:var(--success-hover)}.btn-danger{background-color:var(--danger-color);color:#fff}.btn-outline{background-color:#fff;border:1px solid var(--border-color);color:var(--text-main)}.btn-outline:hover{border-color:#d1d5db;background-color:#f9fafb}.btn-ghost{background-color:transparent;color:var(--text-muted)}.btn-ghost:hover{background-color:#f3f4f6;color:var(--text-main)}input,textarea,select{width:100%;padding:.75rem 1rem;background-color:#fff;border:1px solid var(--border-color);color:var(--text-main);border-radius:var(--radius);font-family:inherit;font-size:.95rem;transition:all .2s}input:focus,textarea:focus,select:focus{outline:none;border-color:var(--primary-color);box-shadow:0 0 0 3px #2563eb1a}.container{max-width:1100px;margin:0 auto;padding:0 1rem}.container-fluid{width:100%;padding:0 2rem}.navbar{display:flex;justify-content:space-between;align-items:center;padding:.75rem 0;border-bottom:1px solid var(--border-color);background-color:#fff;position:sticky;top:0;z-index:10}.navbar .brand{font-size:1.25rem;font-weight:700;color:var(--text-main);display:flex;align-items:center;gap:.5rem}.navbar .nav-links{display:flex;gap:1rem;align-items:center}.tab-nav{display:flex;gap:2rem;border-bottom:1px solid var(--border-color);margin-bottom:2rem;background-color:#fff;padding:0 1rem}.tab-nav-item{padding:1rem 0;color:var(--text-muted);font-weight:500;cursor:pointer;position:relative}.tab-nav-item:hover{color:var(--text-main)}.tab-nav-item.active{color:var(--text-main);font-weight:600}.tab-nav-item.active:after{content:"";position:absolute;bottom:-1px;left:0;right:0;height:3px;background-color:var(--text-main);border-radius:3px 3px 0 0}.text-center{text-align:center}.text-muted{color:var(--text-muted)}.text-danger{color:var(--danger-color)}.text-success{color:var(--success-color)}.text-warning{color:var(--warning-color)}.mt-1{margin-top:1rem}.mt-2{margin-top:2rem}.mb-1{margin-bottom:1rem}.mb-2{margin-bottom:2rem}.flex{display:flex}.flex-col{flex-direction:column}.gap-1{gap:1rem}.gap-2{gap:2rem}.items-center{align-items:center}.justify-between{justify-content:space-between}.justify-center{justify-content:center}.grid{display:grid}.grid-cols-2{grid-template-columns:repeat(2,1fr)}.grid-cols-3{grid-template-columns:repeat(auto-fill,minmax(280px,1fr))}@media(max-width:768px){.grid-cols-2,.grid-cols-3{grid-template-columns:1fr}.navbar{flex-direction:column;gap:1rem}}.card{background-color:var(--panel-bg);border:1px solid var(--border-color);border-radius:var(--radius);padding:1.5rem;box-shadow:var(--shadow)}.course-card{display:flex;flex-direction:column;overflow:hidden;padding:0;transition:transform .2s,box-shadow .2s;cursor:pointer;height:100%}.course-card:hover{transform:translateY(-2px);box-shadow:0 10px 15px -3px #0000001a}.course-card img{width:100%;height:160px;object-fit:cover;border-bottom:1px solid var(--border-color)}.course-card-content{padding:1rem;display:flex;flex-direction:column;flex-grow:1}.course-add-card{display:flex;flex-direction:column;justify-content:center;align-items:center;border:2px dashed #d1d5db;border-radius:var(--radius);background-color:#fafafa;color:var(--text-muted);cursor:pointer;height:250px;transition:all .2s}.course-add-card:hover{border-color:var(--text-main);color:var(--text-main);background-color:#fff}.overlay{position:fixed;inset:0;background-color:#1f232866;display:flex;justify-content:center;align-items:center;z-index:50;padding:1rem}.modal{background-color:var(--panel-bg);border-radius:var(--radius);width:100%;max-width:650px;box-shadow:0 20px 25px -5px #0000001a,0 10px 10px -5px #0000000a;max-height:90vh;overflow-y:auto}.modal-header{display:flex;justify-content:space-between;align-items:center;padding:1.5rem;border-bottom:1px solid var(--border-color)}.modal-body{padding:1.5rem}.modal-footer{display:flex;justify-content:space-between;align-items:center;padding:1.5rem;border-top:1px solid var(--border-color);background-color:#f9fafb}.access-options{display:grid;grid-template-columns:repeat(5,1fr);border:1px solid var(--border-color);border-radius:var(--radius);overflow:hidden;margin-bottom:1.5rem}.access-option{padding:1rem .5rem;text-align:center;border-right:1px solid var(--border-color);cursor:pointer;background-color:#fff;transition:background-color .2s;display:flex;flex-direction:column;align-items:center;gap:.5rem}.access-option:last-child{border-right:none}.access-option:hover{background-color:#f9fafb}.access-option.selected{background-color:#2563eb0d}.access-option-title{font-weight:600;font-size:.85rem;color:var(--text-main)}.access-option-desc{font-size:.75rem;color:var(--text-muted)}.access-radio{margin-bottom:.25rem}.switch{position:relative;display:inline-block;width:44px;height:24px}.switch input{opacity:0;width:0;height:0}.slider{position:absolute;cursor:pointer;inset:0;background-color:#ccc;transition:.4s;border-radius:24px}.slider:before{position:absolute;content:"";height:18px;width:18px;left:3px;bottom:3px;background-color:#fff;transition:.4s;border-radius:50%}input:checked+.slider{background-color:var(--success-color)}input:checked+.slider:before{transform:translate(20px)}.w-full{width:100%}.lesson-list{display:flex;flex-direction:column}.lesson-list-item{display:flex;align-items:center;gap:10px;padding:.75rem;border-radius:var(--radius);cursor:pointer;transition:all .2s}.lesson-list-item:hover{background-color:#f3f4f6}.lesson-list-item.selected{background-color:#2563eb1a;color:var(--primary-color)}