:root{--primary:#4361ee;--primary-light:#4895ef;--secondary:#3f37c9;--success:#4cc9f0;--info:#4895ef;--warning:#f72585;--light-bg:#f8f9fa;--sidebar-width:250px}body{background-color:#f5f7fb;font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif}#sidebar{width:var(--sidebar-width);background:linear-gradient(180deg,var(--primary) 0,var(--secondary) 100%);color:white;height:100vh;position:fixed;transition:all .3s;z-index:1000;box-shadow:3px 0 10px rgba(0,0,0,.1)}.sidebar-header{padding:20px;background-color:rgba(0,0,0,.1)}.sidebar-header h3{font-weight:700;margin-bottom:0}.sidebar-header p{font-size:.85rem;opacity:.8;margin-bottom:0}.sidebar-menu{padding:0;list-style:none}.sidebar-menu li{padding:0}.sidebar-menu a{color:white;padding:12px 20px;display:block;text-decoration:none;transition:all .2s;border-left:3px solid transparent}.sidebar-menu a.active,.sidebar-menu a:hover{background-color:rgba(255,255,255,.1);border-left:3px solid white}.sidebar-menu i{margin-right:10px;width:20px;text-align:center}#content{margin-left:var(--sidebar-width);transition:all .3s;min-height:100vh}#topbar{background-color:white;box-shadow:0 2px 10px rgba(0,0,0,.08);padding:15px 25px;position:sticky;top:0;z-index:100}.search-box{position:relative;max-width:400px}.search-box input{padding-left:40px;border-radius:20px;background-color:var(--light-bg);border:1px solid #eaeaea}.search-box i{position:absolute;left:15px;top:50%;transform:translateY(-50%);color:#6c757d}.user-menu img{width:40px;height:40px;border-radius:50%;object-fit:cover;margin-right:10px}.dashboard-card{border-radius:10px;border:none;box-shadow:0 4px 6px rgba(0,0,0,.05);transition:transform .3s,box-shadow .3s;margin-bottom:20px}.dashboard-card:hover{transform:translateY(-5px);box-shadow:0 10px 15px rgba(0,0,0,.1)}.card-icon{width:60px;height:60px;border-radius:10px;display:flex;align-items:center;justify-content:center;font-size:24px;color:white}.bg-primary-light{background-color:var(--primary-light)}.bg-success-light{background-color:var(--success)}.bg-warning-light{background-color:var(--warning)}.bg-info-light{background-color:var(--info)}.class-item{border-left:3px solid var(--primary);padding:10px 15px;margin-bottom:10px;background-color:white;border-radius:0 5px 5px 0}.class-time{font-weight:600;color:var(--primary)}.announcement-item{padding:15px;border-radius:8px;background-color:white;margin-bottom:15px;border-left:4px solid var(--primary)}.announcement-date{font-size:.85rem;color:#6c757d}.grade-progress{height:8px;border-radius:4px}.student-item{display:flex;align-items:center;padding:10px 0;border-bottom:1px solid #eee}.student-item:last-child{border-bottom:none}.student-avatar{width:40px;height:40px;border-radius:50%;background-color:var(--primary-light);display:flex;align-items:center;justify-content:center;color:white;font-weight:600;margin-right:15px}.activity-table{background-color:white;border-radius:8px;overflow:hidden;box-shadow:0 4px 6px rgba(0,0,0,.05)}.activity-table th{background-color:var(--light-bg);border:none;font-weight:600;color:#495057}.activity-table td{border-color:#f1f3f4;vertical-align:middle}.badge-completed{background-color:#d4edda;color:#155724}.badge-pending{background-color:#fff3cd;color:#856404}#mobile-sidebar{position:fixed;top:0;left:-100%;width:280px;height:100vh;background:linear-gradient(180deg,var(--primary) 0,var(--secondary) 100%);z-index:2000;transition:left .3s;overflow-y:auto}#mobile-sidebar.show{left:0}.overlay{position:fixed;top:0;left:0;width:100%;height:100%;background-color:rgba(0,0,0,.5);z-index:1500;display:none}.overlay.show{display:block}@media (max-width:992px){#sidebar{margin-left:-250px}#content,#sidebar.show{margin-left:0}#content.sidebar-show{margin-left:250px}}.btn-primary{background-color:var(--primary);border-color:var(--primary)}.btn-primary:hover{background-color:var(--secondary);border-color:var(--secondary)}