@import"https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap";:root{--sd-color-primary: #2563eb;--sd-color-primary-dark: #1d4ed8;--sd-color-primary-light: #dbeafe;--sd-color-accent: #f59e0b;--sd-color-success: #16a34a;--sd-color-success-light: #dcfce7;--sd-color-danger: #dc2626;--sd-color-danger-light: #fee2e2;--sd-color-warning: #f59e0b;--sd-color-ink: #0f172a;--sd-color-body: #334155;--sd-color-muted: #64748b;--sd-color-border: #e2e8f0;--sd-color-surface: #ffffff;--sd-color-bg: #f8fafc;--sd-space-1: 4px;--sd-space-2: 8px;--sd-space-3: 12px;--sd-space-4: 16px;--sd-space-5: 24px;--sd-space-6: 32px;--sd-space-7: 48px;--sd-space-8: 64px;--sd-radius-sm: 6px;--sd-radius-md: 10px;--sd-radius-lg: 16px;--sd-radius-full: 999px;--sd-shadow-sm: 0 1px 2px rgba(15, 23, 42, .06);--sd-shadow-md: 0 4px 12px rgba(15, 23, 42, .08);--sd-shadow-lg: 0 12px 32px rgba(15, 23, 42, .12);--sd-font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif}.sd-scope{font-family:var(--sd-font-sans);color:var(--sd-color-body)}.sd-scope h1,.sd-scope h2,.sd-scope h3,.sd-scope h4{color:var(--sd-color-ink);font-weight:800;letter-spacing:-.02em}.sd-container{max-width:1140px;margin:0 auto;padding:0 var(--sd-space-5)}.sd-section{padding:var(--sd-space-8) 0}.sd-btn{display:inline-flex;align-items:center;justify-content:center;gap:var(--sd-space-2);font-family:var(--sd-font-sans);font-weight:600;font-size:.95rem;padding:.7rem 1.4rem;border-radius:var(--sd-radius-md);border:1px solid transparent;cursor:pointer;text-decoration:none;transition:transform .12s ease,box-shadow .12s ease,background-color .12s ease,color .12s ease;line-height:1.2}.sd-btn:hover{transform:translateY(-1px);text-decoration:none}.sd-btn:active{transform:translateY(0)}.sd-btn-primary{background:var(--sd-color-primary);color:#fff;box-shadow:var(--sd-shadow-sm)}.sd-btn-primary:hover{background:var(--sd-color-primary-dark);color:#fff;box-shadow:var(--sd-shadow-md)}.sd-btn-outline{background:transparent;color:var(--sd-color-primary);border-color:var(--sd-color-primary)}.sd-btn-outline:hover{background:var(--sd-color-primary-light);color:var(--sd-color-primary-dark)}.sd-btn-ghost{background:transparent;color:var(--sd-color-body)}.sd-btn-ghost:hover{background:var(--sd-color-bg);color:var(--sd-color-ink)}.sd-btn-lg{padding:.9rem 1.8rem;font-size:1.05rem}.sd-btn-block{width:100%}.sd-card{background:var(--sd-color-surface);border:1px solid var(--sd-color-border);border-radius:var(--sd-radius-lg);box-shadow:var(--sd-shadow-sm)}.sd-card-body{padding:var(--sd-space-6)}.sd-badge{display:inline-flex;align-items:center;gap:6px;font-size:.75rem;font-weight:700;text-transform:uppercase;letter-spacing:.04em;padding:.3rem .7rem;border-radius:var(--sd-radius-full)}.sd-badge-primary{background:var(--sd-color-primary-light);color:var(--sd-color-primary-dark)}.sd-badge-success{background:var(--sd-color-success-light);color:var(--sd-color-success)}.sd-badge-warning{background:#fef3c7;color:#92400e}.sd-badge-muted{background:var(--sd-color-bg);color:var(--sd-color-muted)}.sd-field{margin-bottom:var(--sd-space-4);text-align:left}.sd-field label{display:block;font-weight:600;font-size:.85rem;color:var(--sd-color-ink);margin-bottom:var(--sd-space-2)}.sd-field .form-control,.sd-field select.form-control,.sd-field input.form-control{width:100%;height:auto;line-height:1.4;font-family:var(--sd-font-sans);border:1px solid var(--sd-color-border);border-radius:var(--sd-radius-md);padding:.65rem .9rem;font-size:.95rem;color:var(--sd-color-ink);background:#fff;transition:border-color .12s ease,box-shadow .12s ease}.sd-field .form-control:focus{outline:none;border-color:var(--sd-color-primary);box-shadow:0 0 0 3px var(--sd-color-primary-light)}.sd-field .is-invalid{border-color:var(--sd-color-danger)}.sd-field .invalid-feedback{color:var(--sd-color-danger);font-size:.82rem;margin-top:4px}.sd-auth-wrap{min-height:60vh;display:flex;align-items:center;justify-content:center;padding:var(--sd-space-8) var(--sd-space-4)}.sd-auth-card{width:100%;max-width:440px;padding:var(--sd-space-7)}.sd-auth-card h1{font-size:1.5rem;margin-bottom:var(--sd-space-2)}.sd-auth-sub{color:var(--sd-color-muted);margin-bottom:var(--sd-space-6);font-size:.92rem}.sd-auth-footer{text-align:center;margin-top:var(--sd-space-5);font-size:.9rem;color:var(--sd-color-muted)}.sd-hero{position:relative;background:linear-gradient(160deg,#eef2ff,#f8fafc 55%,#fff);padding:var(--sd-space-7) 0 var(--sd-space-8);overflow:hidden}.sd-hero:before,.sd-hero:after{content:"";position:absolute;border-radius:50%;filter:blur(60px);z-index:0;pointer-events:none}.sd-hero:before{width:420px;height:420px;top:-180px;right:-120px;background:radial-gradient(circle,#2563eb38,#2563eb00 70%)}.sd-hero:after{width:320px;height:320px;bottom:-160px;left:-100px;background:radial-gradient(circle,#f59e0b29,#f59e0b00 70%)}.sd-hero .sd-container{position:relative;z-index:1}.sd-hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:var(--sd-space-7);align-items:center}@media (max-width: 900px){.sd-hero-grid{grid-template-columns:1fr;text-align:center}.sd-hero-cta,.sd-hero-stats{justify-content:center}}.sd-eyebrow{display:inline-flex;align-items:center;gap:6px;background:var(--sd-color-primary-light);color:var(--sd-color-primary-dark);font-weight:700;font-size:.78rem;text-transform:uppercase;letter-spacing:.06em;padding:.4rem .85rem;border-radius:var(--sd-radius-full);margin-bottom:var(--sd-space-4)}.sd-hero h1{font-size:clamp(2rem,4vw,3.1rem);line-height:1.12;margin-bottom:var(--sd-space-4)}.sd-hero-lead{font-size:1.1rem;color:var(--sd-color-body);margin-bottom:var(--sd-space-5);max-width:44ch}.sd-hero-cta{display:flex;gap:var(--sd-space-3);flex-wrap:wrap;margin-bottom:var(--sd-space-5)}.sd-hero-stats{display:flex;gap:var(--sd-space-6);flex-wrap:wrap}.sd-hero-stat-num{font-size:1.6rem;font-weight:800;color:var(--sd-color-ink)}.sd-hero-stat-label{font-size:.82rem;color:var(--sd-color-muted)}@keyframes sd-colearn-draw{0%{stroke-dashoffset:1;opacity:1}55%{stroke-dashoffset:0;opacity:1}78%{stroke-dashoffset:0;opacity:1}to{stroke-dashoffset:0;opacity:0}}.sd-hero-panel{position:relative;padding:var(--sd-space-4)}.sd-mock-window{background:var(--sd-color-surface);border:1px solid var(--sd-color-border);border-radius:var(--sd-radius-lg);box-shadow:var(--sd-shadow-lg);overflow:hidden}.sd-mock-window-test{position:relative;z-index:1;animation:sd-hero-mock-test 9s ease-in-out infinite}.sd-mock-window-colearn{position:absolute;top:0;right:0;bottom:0;left:0;z-index:2;animation:sd-hero-mock-colearn 9s ease-in-out infinite}@keyframes sd-hero-mock-test{0%,38%{opacity:1}48%,88%{opacity:0}98%,to{opacity:1}}@keyframes sd-hero-mock-colearn{0%,38%{opacity:0}48%,88%{opacity:1}98%,to{opacity:0}}.sd-mock-titlebar{display:flex;align-items:center;gap:6px;padding:var(--sd-space-3) var(--sd-space-4);background:var(--sd-color-bg);border-bottom:1px solid var(--sd-color-border)}.sd-mock-dot{width:9px;height:9px;border-radius:50%}.sd-mock-timer{margin-left:auto;font-variant-numeric:tabular-nums;font-weight:800;font-size:.82rem;color:var(--sd-color-ink);background:var(--sd-color-surface);border:1px solid var(--sd-color-border);border-radius:var(--sd-radius-full);padding:.2rem .6rem}.sd-mock-body{padding:var(--sd-space-5)}.sd-mock-palette{display:grid;grid-template-columns:repeat(10,1fr);gap:5px;margin:var(--sd-space-4) 0 var(--sd-space-5);max-width:220px}.sd-mock-cell{aspect-ratio:1;border-radius:4px;border:1px solid var(--sd-color-border);background:var(--sd-color-surface)}.sd-mock-cell.is-filled{background:var(--sd-color-primary);border-color:var(--sd-color-primary)}.sd-mock-cell.is-current{outline:2px solid var(--sd-color-ink);outline-offset:1px}.sd-mock-line{height:9px;background:var(--sd-color-bg);border-radius:var(--sd-radius-full);margin-bottom:8px}.sd-mock-options{display:flex;flex-direction:column;gap:8px;margin-top:var(--sd-space-4)}.sd-mock-option{font-size:.78rem;font-weight:600;color:var(--sd-color-muted);border:1px solid var(--sd-color-border);border-radius:var(--sd-radius-md);padding:.45rem .7rem}.sd-mock-option.is-selected{border-color:var(--sd-color-primary);background:var(--sd-color-primary-light);color:var(--sd-color-primary-dark)}.sd-mock-room-name{margin-left:auto;font-weight:700;font-size:.85rem;color:var(--sd-color-ink)}.sd-mock-colearn-body{display:flex;flex-direction:column;gap:var(--sd-space-4)}.sd-mock-colearn-people{display:flex;align-items:center;gap:8px}.sd-mock-avatar{width:26px;height:26px;border-radius:50%;display:flex;align-items:center;justify-content:center;color:#fff;font-size:.72rem;font-weight:700;border:2px solid #fff;box-shadow:0 0 0 1px var(--sd-color-border);margin-left:-8px}.sd-mock-avatar:first-child{margin-left:0}.sd-mock-presenting-badge{margin-left:6px;display:inline-flex;align-items:center;gap:5px;font-size:.7rem;font-weight:700;padding:3px 9px;border-radius:var(--sd-radius-full);background:var(--sd-color-primary-light);color:var(--sd-color-primary-dark);white-space:nowrap}.sd-mock-whiteboard{border:1px solid var(--sd-color-border);border-radius:var(--sd-radius-md);background:#fff;background-image:radial-gradient(var(--sd-color-border) 1px,transparent 1px);background-size:14px 14px;height:150px}.sd-mock-whiteboard-svg{width:100%;height:100%}.sd-mock-wb-path{fill:none;stroke:var(--sd-color-ink);stroke-width:3;stroke-linecap:round;stroke-linejoin:round;stroke-dasharray:1;stroke-dashoffset:1;animation:sd-colearn-draw 4s ease-in-out infinite}.sd-mock-wb-path-2{stroke:var(--sd-color-primary);animation-delay:.6s}.sd-floating-chip{position:absolute;display:flex;align-items:center;gap:6px;background:var(--sd-color-surface);border:1px solid var(--sd-color-border);border-radius:var(--sd-radius-full);box-shadow:var(--sd-shadow-md);padding:.5rem .9rem;font-size:.8rem;font-weight:700;color:var(--sd-color-ink);animation:sd-float 4s ease-in-out infinite}.sd-floating-chip .fas,.sd-floating-chip .far{color:var(--sd-color-success)}.sd-floating-chip-1{top:-14px;right:-18px;animation-delay:0s}.sd-floating-chip-2{bottom:-14px;left:-14px;animation-delay:1.4s}@media (max-width: 900px){.sd-floating-chip{display:none}}@keyframes sd-float{0%,to{transform:translateY(0)}50%{transform:translateY(-6px)}}.cl-hub{background:radial-gradient(circle at top left,var(--sd-color-primary-light) 0%,transparent 55%);border-radius:var(--sd-radius-lg);padding:var(--sd-space-6) var(--sd-space-5)}.cl-hub-header{display:flex;align-items:center;gap:var(--sd-space-4);margin-bottom:var(--sd-space-6)}.cl-hub-header h2{margin:0 0 4px}.cl-hub-header p{margin:0;color:var(--sd-color-muted);max-width:60ch}.cl-hub-header-icon{width:52px;height:52px;border-radius:var(--sd-radius-lg);background:linear-gradient(135deg,var(--sd-color-primary) 0%,var(--sd-color-primary-dark) 100%);color:#fff;display:flex;align-items:center;justify-content:center;font-size:1.3rem;flex-shrink:0;box-shadow:var(--sd-shadow-md)}.cl-hub-grid{display:grid;grid-template-columns:2fr 1fr;gap:var(--sd-space-5);align-items:start}@media (max-width: 800px){.cl-hub-grid{grid-template-columns:1fr}}.cl-hub-main,.cl-hub-side{padding:var(--sd-space-5)}.cl-hub-side h3{display:flex;align-items:center;gap:var(--sd-space-2)}.cl-group-list{display:flex;flex-direction:column;gap:var(--sd-space-3);margin-top:var(--sd-space-4)}.cl-group-row{display:flex;align-items:center;justify-content:space-between;gap:var(--sd-space-4);padding:var(--sd-space-4);border:1px solid var(--sd-color-border);border-radius:var(--sd-radius-md);text-decoration:none;color:inherit;transition:border-color .15s ease,box-shadow .15s ease,transform .15s ease}.cl-group-row:hover{border-color:var(--sd-color-primary);box-shadow:var(--sd-shadow-md);transform:translateY(-1px);text-decoration:none;color:inherit}.cl-group-row-main{display:flex;align-items:center;gap:var(--sd-space-4)}.cl-group-name{font-weight:700;color:var(--sd-color-ink)}.cl-group-members{font-size:.82rem;color:var(--sd-color-muted)}.cl-group-enter{font-size:.85rem;font-weight:600;color:var(--sd-color-primary);display:flex;align-items:center;gap:6px;white-space:nowrap}.cl-group-enter i{transition:transform .15s ease}.cl-group-row:hover .cl-group-enter i{transform:translate(3px)}.cl-avatar-stack{display:flex}.cl-avatar{width:36px;height:36px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.85rem;font-weight:700;color:#fff;border:2px solid #fff;margin-left:-10px;flex-shrink:0}.cl-avatar:first-child{margin-left:0}.cl-avatar-0{background:#2952e3}.cl-avatar-1{background:#e04848}.cl-avatar-2{background:#1f9d55}.cl-avatar-3{background:#f5a623}.cl-avatar-4{background:#8b5cf6}.cl-empty-state{display:flex;flex-direction:column;align-items:center;gap:var(--sd-space-3);padding:var(--sd-space-7) var(--sd-space-4);color:var(--sd-color-muted);text-align:center}.cl-empty-state-icon{width:56px;height:56px;border-radius:50%;background:var(--sd-color-primary-light);color:var(--sd-color-primary);display:flex;align-items:center;justify-content:center;font-size:1.4rem}.cl-empty-state p{margin:0}.cl-input-icon-wrap{position:relative}.cl-input-icon{position:absolute;left:12px;top:50%;transform:translateY(-50%);color:var(--sd-color-muted);font-size:.85rem;pointer-events:none}.cl-input-icon-wrap .form-control{padding-left:34px}.cl-create-btn{display:flex;align-items:center;justify-content:center;gap:8px}.sd-lb-card{padding:var(--sd-space-4) var(--sd-space-5);max-width:720px;margin:0 auto}.sd-lb-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column}.sd-lb-row{display:grid;grid-template-columns:40px 1fr auto auto;align-items:center;gap:var(--sd-space-4);padding:var(--sd-space-3) var(--sd-space-3);border-radius:var(--sd-radius-md);border-bottom:1px solid var(--sd-color-border)}.sd-lb-list li:last-child{border-bottom:none}.sd-lb-row:hover{background:var(--sd-color-primary-light)}.sd-lb-row-top{background:linear-gradient(90deg,var(--sd-color-primary-light),transparent);font-weight:700}.sd-lb-rank{font-size:1rem;font-weight:800;color:var(--sd-color-muted);text-align:center}.sd-lb-rank-1,.sd-lb-rank-2,.sd-lb-rank-3{font-size:1.3rem}.sd-lb-name{color:var(--sd-color-ink);font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.sd-lb-test{color:var(--sd-color-muted);font-size:.8rem;white-space:nowrap}.sd-lb-score{font-weight:800;color:var(--sd-color-primary);font-size:1.1rem;min-width:48px;text-align:right}@media (max-width: 560px){.sd-lb-row{grid-template-columns:32px 1fr auto}.sd-lb-test{display:none}}.sd-features-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:var(--sd-space-5)}@media (max-width: 900px){.sd-features-grid{grid-template-columns:1fr}}.sd-feature-icon{width:44px;height:44px;border-radius:var(--sd-radius-md);background:var(--sd-color-primary-light);color:var(--sd-color-primary-dark);display:flex;align-items:center;justify-content:center;font-size:1.25rem;margin-bottom:var(--sd-space-4)}.sd-section-head{text-align:center;max-width:640px;margin:0 auto var(--sd-space-7)}.sd-section-head p{color:var(--sd-color-muted);font-size:1.02rem}.sd-error-wrap{min-height:55vh;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:var(--sd-space-8) var(--sd-space-4)}.sd-error-code{font-size:5rem;font-weight:800;color:var(--sd-color-primary);line-height:1;margin-bottom:var(--sd-space-3)}.sd-error-wrap p{color:var(--sd-color-muted);max-width:46ch;margin-bottom:var(--sd-space-6)}.sd-navbar.navbar{background:var(--sd-color-surface)!important;border-bottom:1px solid var(--sd-color-border);box-shadow:var(--sd-shadow-sm);padding-top:var(--sd-space-3);padding-bottom:var(--sd-space-3)}.sd-navbar .navbar-brand{font-family:var(--sd-font-sans);font-weight:800;font-size:1.15rem;color:var(--sd-color-ink)!important;display:inline-flex;align-items:center;gap:8px}.sd-navbar .nav-link,.sd-navbar .navbar-nav .nav-item.dropdown>.nav-link{font-family:var(--sd-font-sans);font-weight:600;font-size:.92rem;color:var(--sd-color-body)!important}.sd-navbar .nav-link:hover{color:var(--sd-color-primary)!important}.sd-navbar .dropdown-content{border-radius:var(--sd-radius-md);border:1px solid var(--sd-color-border);box-shadow:var(--sd-shadow-md);background-color:var(--sd-color-surface);padding:var(--sd-space-3) 0 var(--sd-space-2);margin-top:0}.sd-navbar .dropdown-content a{font-size:.9rem;color:var(--sd-color-body)}.sd-navbar .dropdown-content a:hover{background-color:var(--sd-color-primary-light)!important;color:var(--sd-color-primary-dark)}.sd-navbar .navbar-toggler{border-color:var(--sd-color-border);padding:6px 8px}.sd-navbar .navbar-toggler-icon{background-image:url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='30' height='30' viewBox='0 0 30 30'%3e%3cpath stroke='%230f172a' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e")}@media (max-width: 575.98px){.sd-navbar .navbar-collapse{margin-top:var(--sd-space-3);padding-top:var(--sd-space-3);border-top:1px solid var(--sd-color-border)}.sd-navbar .navbar-nav{gap:2px}.sd-navbar .nav-link{padding-top:var(--sd-space-2);padding-bottom:var(--sd-space-2)}}.sd-navbar .search_input{border-radius:var(--sd-radius-full)!important;border:1px solid var(--sd-color-border)!important}.sd-search-form{position:relative;display:flex;align-items:center;width:260px;max-width:60vw}.sd-search-icon{position:absolute;left:14px;color:var(--sd-color-muted);font-size:.8rem;pointer-events:none}.sd-search-input{width:100%;font-family:var(--sd-font-sans);padding:.5rem 2.5rem .5rem 2.3rem;border-radius:var(--sd-radius-full);border:1px solid var(--sd-color-border);background:var(--sd-color-bg);font-size:.85rem;color:var(--sd-color-ink);transition:border-color .12s ease,background .12s ease,box-shadow .12s ease}.sd-search-input::placeholder{color:var(--sd-color-muted)}.sd-search-input:focus{outline:none;border-color:var(--sd-color-primary);background:var(--sd-color-surface);box-shadow:0 0 0 3px var(--sd-color-primary-light)}.sd-search-submit{position:absolute;right:4px;width:26px;height:26px;border-radius:50%;border:none;background:var(--sd-color-primary);color:#fff;display:flex;align-items:center;justify-content:center;font-size:.7rem;cursor:pointer;transition:background .12s ease}.sd-search-submit:hover{background:var(--sd-color-primary-dark)}.sd-lesson-card{display:flex;gap:var(--sd-space-4);padding:var(--sd-space-4);margin-bottom:var(--sd-space-4);align-items:flex-start}.sd-lesson-thumb{width:64px;height:64px;border-radius:var(--sd-radius-md);flex-shrink:0;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:800;font-size:1.4rem;overflow:hidden}.sd-lesson-thumb img{width:100%;height:100%;object-fit:cover}.sd-lesson-thumb i{font-size:1.6rem}.sd-thumb-0{background:linear-gradient(135deg,#2563eb,#1d4ed8)}.sd-thumb-1{background:linear-gradient(135deg,#f59e0b,#d97706)}.sd-thumb-2{background:linear-gradient(135deg,#16a34a,#15803d)}.sd-thumb-3{background:linear-gradient(135deg,#db2777,#a21caf)}.sd-avatar{display:inline-flex;align-items:center;justify-content:center;border-radius:50%;color:#fff;font-weight:800;flex-shrink:0;line-height:1}.sd-lesson-meta{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-bottom:4px}.sd-lesson-title{font-size:1.05rem;font-weight:700;color:var(--sd-color-ink);display:block;margin:4px 0 var(--sd-space-3)}.sd-lesson-title:hover{color:var(--sd-color-primary)}.sd-lesson-actions{display:flex;gap:var(--sd-space-2);flex-wrap:wrap}.sd-icon-btn{display:inline-flex;align-items:center;gap:6px;font-size:.82rem;font-weight:600;color:var(--sd-color-muted);background:var(--sd-color-bg);border-radius:var(--sd-radius-full);padding:.35rem .75rem;border:1px solid transparent;transition:background .12s ease,color .12s ease}.sd-icon-btn:hover{background:var(--sd-color-primary-light);color:var(--sd-color-primary-dark);text-decoration:none}.sd-icon-btn.sd-icon-btn-active{background:var(--sd-color-primary-light);color:var(--sd-color-primary-dark)}.sd-icon-btn.sd-icon-btn-danger:hover{background:var(--sd-color-danger-light);color:var(--sd-color-danger)}.sd-animate{opacity:0;transform:translateY(16px);transition:opacity .5s ease,transform .5s ease}.sd-animate.sd-in-view{opacity:1;transform:translateY(0)}