:root{--bg:#f6f7fb;--surface:#fff;--border:#e4e7ee;--text:#1a1f2b;--text-muted:#5b6472;--brand:#1f3a8a;--brand-soft:#eef2ff;--panel-border:var(--line,#d1d5db);--radius:16px;--radius-sm:10px;--radius-pill:999px;--shadow:0 1px 2px #1018280a, 0 8px 24px #1018280f;--shadow-hover:0 2px 4px #1018280f, 0 16px 40px #1018281f}*{box-sizing:border-box}html,body{margin:0;padding:0}body{background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased;text-rendering:optimizelegibility;font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;line-height:1.55}a{color:inherit;text-decoration:none}.page{flex-direction:column;min-height:100vh;display:flex}.container{width:100%;max-width:1040px;margin:0 auto;padding:0 24px}.hero{background:radial-gradient(1200px 400px at 50% -10%, var(--brand-soft), transparent 70%), var(--bg);text-align:center;padding:88px 0 56px}.brand-mark{border:1px solid var(--border);background:var(--surface);border-radius:var(--radius-pill);box-shadow:var(--shadow);color:var(--text-muted);align-items:center;gap:10px;margin-bottom:28px;padding:6px 14px 6px 8px;font-size:14px;font-weight:600;display:inline-flex}.brand-mark .dot{color:#fff;background:linear-gradient(135deg,#2563eb,#7c3aed);border-radius:8px;justify-content:center;align-items:center;width:24px;height:24px;font-size:14px;font-weight:800;display:inline-flex}.brand-mark.compact{margin-bottom:0}.brand-mark img{border-radius:8px}.app-shell-topbar{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;display:flex}.app-shell-topbar.hero-topbar{margin-bottom:8px}.app-shell-meta{align-items:center;gap:10px;font-size:14px;display:inline-flex}.app-shell-meta.muted{color:var(--text-muted)}.app-shell-actions{flex-wrap:wrap;align-items:center;gap:10px;display:inline-flex}.app-shell-link{color:var(--brand);align-items:center;font-weight:700;display:inline-flex}.app-shell-button{appearance:none;font:inherit;cursor:pointer;border-radius:8px;justify-content:center;align-items:center;padding:6px 12px;font-size:14px;font-weight:700;text-decoration:none;display:inline-flex}.app-shell-button-primary{border:1px solid var(--brand);background:var(--brand);color:#fff}.app-shell-button-secondary{border:1px solid var(--panel-border);color:var(--text);background:0 0}.app-shell-menu{position:relative}.app-shell-menu-trigger{cursor:pointer;background:0 0;border:none;padding:4px 0;font-size:14px;font-weight:700}.app-shell-menu-panel{background:var(--surface);border:1px solid var(--panel-border);border-radius:var(--radius-sm);z-index:50;min-width:220px;padding:8px 0;font-size:13px;position:absolute;top:calc(100% + 4px);right:0;box-shadow:0 4px 16px #0000001f}.app-shell-menu-copy{color:var(--text-muted);padding:6px 14px;line-height:1.4}.app-shell-menu-copy strong{color:var(--text)}.app-shell-menu-separator{border:none;border-top:1px solid var(--border);margin:4px 0}.app-shell-menu-item{text-align:left;cursor:pointer;width:100%;font:inherit;color:var(--text);background:0 0;border:none;padding:8px 14px;font-size:13px;display:block}.app-shell-menu-item:hover{background:#f8fafc}.hero h1{letter-spacing:-.02em;margin:0 0 16px;font-size:clamp(2.2rem,5vw,3.4rem);font-weight:800;line-height:1.08}.hero h1 .accent{background:linear-gradient(135deg,#2563eb,#7c3aed);color:#0000;-webkit-background-clip:text;background-clip:text}.hero p{color:var(--text-muted);max-width:560px;margin:0 auto;font-size:clamp(1rem,2.2vw,1.2rem)}.tools{padding:24px 0 64px}.grid{grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:20px;display:grid}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);flex-direction:column;height:100%;padding:18px 18px 16px;transition:transform .18s,box-shadow .18s,border-color .18s;display:flex;position:relative}.card-compact .tagline{margin-bottom:10px}.card-hidden-admin{opacity:.92;border-style:dashed;border-color:#c4b5fd}.card-open{background:linear-gradient(#eff8ff 0%,#fff 42%);border-color:#bfdbfe}.card-login{background:linear-gradient(#f5f3ff 0%,#fff 42%);border-color:#ddd6fe}a.card:hover{box-shadow:var(--shadow-hover);border-color:#d3d8e4;transform:translateY(-3px)}a.card.card-open:hover{border-color:#93c5fd}a.card.card-login:hover{border-color:#c4b5fd}.card.soon{opacity:.85}.tools-section-title{letter-spacing:.04em;text-transform:uppercase;margin:8px 0 14px;font-size:.92rem;font-weight:700}.tools-section-open{color:#0369a1}.tools-section-login{color:#6d28d9;margin-top:28px}.card-help{color:#0f172a;cursor:pointer;z-index:2;background:#ffffffeb;border:1px solid #0f172a1f;border-radius:999px;width:34px;height:34px;font-size:11px;font-weight:700;position:absolute;top:14px;right:14px}.card-help:hover{color:#fff;background:#0f172a}.card-info{color:#64748b;cursor:pointer;z-index:2;background:#fffffff2;border:1px solid #0f172a24;border-radius:999px;flex-shrink:0;justify-content:center;align-items:center;width:22px;height:22px;font-size:13px;line-height:1;display:inline-flex}.card-info:hover,.card-info[aria-expanded=true]{color:#fff;background:#0f172a;border-color:#0f172a}.card-desc-popover{z-index:4;border:1px solid var(--border);box-shadow:var(--shadow-hover);color:var(--text-muted);background:#fff;border-radius:10px;padding:10px 12px;font-size:.88rem;line-height:1.45;position:absolute;top:72px;left:18px;right:18px}.card-admin-hide{z-index:3;color:#6d28d9;cursor:pointer;background:#fffffff2;border:1px solid #6d28d940;border-radius:999px;justify-content:center;align-items:center;width:32px;height:32px;font-size:14px;line-height:1;display:inline-flex;position:absolute;bottom:14px;right:14px}.card-admin-hide:hover{color:#fff;background:#6d28d9;border-color:#6d28d9}.card-admin-hide.is-hidden{background:#f5f3ff}.card-hidden-badge{color:#6d28d9;letter-spacing:.02em;text-transform:uppercase;vertical-align:middle;background:#f5f3ff;border-radius:999px;margin-left:8px;padding:2px 8px;font-size:.68rem;font-weight:700;display:inline-block}.hero-title-row{flex-wrap:wrap;align-items:flex-end;gap:14px 20px;margin-top:8px;display:flex}.hero-title-row h1{margin:0}.help-hub-btn{cursor:pointer;color:#0f172a;background:#ffffffd9;border:1px solid #0f172a1f;border-radius:999px;padding:8px 14px;font-size:13px;font-weight:650}.help-hub-btn:hover{color:#fff;background:#0f172a}.lang-select select{border:1px solid var(--border);background:#fff;border-radius:10px;padding:8px 10px;font-size:13px;font-weight:600}.sr-only{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.help-modal-backdrop{z-index:80;background:#0f172a8c;justify-content:center;align-items:center;padding:20px;display:flex;position:fixed;inset:0}.help-modal{background:#fff;border-radius:18px;flex-direction:column;gap:14px;width:min(720px,100%);padding:18px;display:flex;box-shadow:0 20px 50px #0f172a47}.help-modal-head{justify-content:space-between;align-items:center;gap:12px;display:flex}.help-modal-head h2{margin:0;font-size:1.15rem}.help-modal-close{cursor:pointer;color:#64748b;background:0 0;border:none;font-size:18px}.help-modal-frame{background:#0f172a;border-radius:14px;width:100%;padding-top:56.25%;position:relative;overflow:hidden}.help-modal-frame iframe{border:0;width:100%;height:100%;position:absolute;inset:0}.help-modal-placeholder{text-align:center;color:var(--text-muted);background:#f8fafc;border:1px dashed #cbd5e1;border-radius:14px;padding:22px}.help-slideshow{background:linear-gradient(160deg,#eff8ff,#f5f3ff 55%,#fff);border:1px solid #e2e8f0;border-radius:14px;min-height:220px;padding:22px 20px 16px}.help-slideshow-progress{letter-spacing:.06em;text-transform:uppercase;color:#64748b;margin:0 0 10px;font-size:12px;font-weight:700}.help-slideshow h3{color:#0f172a;margin:0 0 10px;font-size:1.35rem}.help-slideshow>p{color:#334155;min-height:4.5em;margin:0;font-size:1.02rem;line-height:1.5}.help-slideshow-dots{justify-content:center;gap:6px;margin:18px 0 12px;display:flex}.help-slideshow-dots button{cursor:pointer;background:#cbd5e1;border:none;border-radius:999px;width:8px;height:8px;padding:0}.help-slideshow-dots button.active{background:#0284c7;width:18px}.help-slideshow-nav{justify-content:space-between;gap:10px;display:flex}.help-slideshow-mock{justify-content:center;gap:8px;margin-bottom:12px;display:flex}.help-slideshow-mock span{color:#0f172a;background:linear-gradient(135deg,#bae6fd,#ddd6fe);border-radius:8px;justify-content:center;align-items:center;width:42px;height:28px;font-size:12px;font-weight:700;display:inline-flex}.card-icon{background:var(--brand-soft);border-radius:14px;justify-content:center;align-items:center;width:52px;height:52px;margin-bottom:18px;font-size:26px;display:inline-flex;overflow:hidden}.card-icon img{object-fit:contain;border-radius:10px;width:40px;height:40px;display:block}.card-head{flex-wrap:wrap;justify-content:space-between;align-items:baseline;gap:12px;display:flex}.card-title-row{align-items:center;gap:8px;min-width:0;display:flex}.card-title-row h2{min-width:0}.card h2{margin:0;font-size:1.2rem;font-weight:700}.card .tagline{text-transform:uppercase;letter-spacing:.04em;color:var(--text-muted);margin:4px 0 10px;font-size:.78rem;font-weight:600}.card-compact .card-cta{margin-top:auto}.card p{color:var(--text-muted);flex:1;margin:0 0 20px;font-size:.95rem}.card-cta{align-items:center;gap:6px;font-size:.92rem;font-weight:600;display:inline-flex}.card-cta .arrow{transition:transform .18s}a.card:hover .card-cta .arrow{transform:translate(3px)}.badge-soon{color:var(--text-muted);border:1px solid var(--border);background:#f1f3f8;border-radius:999px;padding:3px 9px;font-size:.72rem;font-weight:600}.footer{border-top:1px solid var(--border);background:var(--surface);margin-top:auto;padding:28px 0}.footer-inner{color:var(--text-muted);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px;font-size:.9rem;display:flex}.footer-inner strong{color:var(--text);font-weight:600}.roster-hero{background:radial-gradient(900px 320px at 40% -20%, var(--brand-soft), transparent 70%), var(--bg);padding:48px 0 28px}.roster-back{color:var(--text-muted);margin-bottom:18px;font-size:.9rem;font-weight:600;display:inline-block}.roster-back:hover{color:var(--brand)}.roster-header-copy{opacity:.75}.roster-hero h1{letter-spacing:-.02em;margin:0 0 8px;font-size:clamp(1.8rem,4vw,2.4rem)}.roster-hero p{color:var(--text-muted);margin:0}.roster-main{padding:8px 0 64px}.roster-empty{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);text-align:center;box-shadow:var(--shadow);padding:36px 28px}.roster-empty h2{margin:0 0 8px}.roster-empty p{color:var(--text-muted);margin:0 0 20px}.roster-cta{background:var(--brand);color:#fff;border-radius:10px;padding:10px 16px;font-weight:700;display:inline-flex}.roster-grid{gap:16px;display:grid}.roster-class{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:18px 20px}.roster-class-head{justify-content:space-between;align-items:baseline;gap:12px;margin-bottom:12px;display:flex}.roster-class-head h2{margin:0;font-size:1.15rem}.roster-class-head span{color:var(--text-muted);font-size:.9rem}.roster-muted{color:var(--text-muted);margin:0}.roster-students{margin:0;padding:0;list-style:none}.roster-students li{border-top:1px solid var(--border);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px 12px;padding:8px 0;display:flex}.roster-student-main{flex-wrap:wrap;align-items:center;gap:8px 12px;min-width:0;display:flex}.roster-student-actions{flex-wrap:wrap;gap:6px;margin-left:auto;display:flex}.roster-btn-sm{padding:4px 8px;font-size:.78rem}.roster-name{font-weight:500}.roster-code{background:var(--brand-soft);color:var(--brand);border-radius:6px;padding:3px 8px;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.85rem}.roster-toolbar{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;margin-bottom:16px;display:flex}.roster-actions{flex-wrap:wrap;gap:8px;margin:0 0 12px;display:flex}.roster-btn{appearance:none;border:1px solid var(--border);background:var(--surface);color:var(--text);font:inherit;cursor:pointer;border-radius:8px;padding:6px 12px;font-size:.85rem;font-weight:600}.roster-btn:hover:not(:disabled){border-color:var(--brand);color:var(--brand)}.roster-btn:disabled{opacity:.55;cursor:not-allowed}.roster-btn-primary{background:var(--brand);border-color:var(--brand);color:#fff}.roster-btn-primary:hover:not(:disabled){color:#fff;filter:brightness(1.05)}.roster-btn-danger{color:#9b1c1c}.roster-btn-danger:hover:not(:disabled){color:#9b1c1c;border-color:#9b1c1c}.roster-flash{border-radius:10px;margin:0 0 14px;padding:10px 12px;font-size:.9rem}.roster-flash-error{color:#9b1c1c;background:#fef2f2;border:1px solid #fecaca}.roster-flash-ok{color:#065f46;background:#ecfdf5;border:1px solid #a7f3d0}.roster-empty .roster-cta{cursor:pointer;font:inherit;border:none}.roster-empty .roster-cta:disabled{opacity:.55;cursor:not-allowed}.roster-class.is-viewer{opacity:.98;border-style:dashed}.roster-access-badge{vertical-align:middle;color:#3730a3;background:#eef2ff;border-radius:6px;margin-left:8px;padding:2px 8px;font-size:.72rem;font-weight:600;display:inline-block}.roster-viewer-hint{color:#64748b;margin:0 0 12px;font-size:.88rem}.roster-share-list{flex-direction:column;gap:6px;margin:0 0 12px;padding:0;list-style:none;display:flex}.roster-share-list li{background:#f8fafc;border-radius:8px;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px;padding:8px 10px;font-size:.85rem;display:flex}.roster-share-overlay{z-index:80;background:#0f172a73;place-items:center;padding:16px;display:grid;position:fixed;inset:0}.roster-share-dialog{background:#fff;border-radius:14px;width:min(440px,100%);max-height:min(90vh,640px);padding:20px;overflow:auto;box-shadow:0 20px 50px #0f172a40}.roster-share-dialog h2{margin:0 0 8px;font-size:1.15rem}.roster-share-label{flex-direction:column;gap:6px;margin:14px 0;font-size:.9rem;font-weight:600;display:flex}.roster-share-input{font:inherit;border:1px solid #cbd5e1;border-radius:8px;padding:10px 12px;font-weight:400}.roster-share-modes{gap:8px;margin-bottom:12px;display:flex}.roster-share-modes button{font:inherit;cursor:pointer;background:#fff;border:1px solid #cbd5e1;border-radius:8px;flex:1;padding:8px 10px}.roster-share-modes button.is-active{color:#3730a3;background:#eef2ff;border-color:#4f46e5;font-weight:600}.roster-share-students{border:1px solid #e2e8f0;border-radius:8px;max-height:220px;margin:0 0 14px;padding:0;list-style:none;overflow:auto}.roster-share-students li{border-bottom:1px solid #f1f5f9;padding:8px 10px}.roster-share-students li:last-child{border-bottom:none}.roster-share-students label{cursor:pointer;align-items:center;gap:8px;font-size:.9rem;display:flex}.roster-share-actions{justify-content:flex-end;gap:8px;display:flex}@keyframes spin{to{transform:rotate(360deg)}}.spinner{border:2px solid var(--line,#d1d5db);border-top-color:var(--brand,#6d28d9);border-radius:50%;width:16px;height:16px;animation:.6s linear infinite spin;display:inline-block}.tool-chrome{margin-bottom:12px}.tool-chrome-inner{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;display:flex}.tool-chrome-left,.tool-chrome-right{flex-wrap:wrap;align-items:center;gap:10px;display:inline-flex}.tool-chrome-back{color:var(--text-muted);font-size:.9rem;font-weight:600}.tool-chrome-back:hover{color:var(--brand)}.tool-chrome-pill{border:1px solid var(--border);background:var(--surface);border-radius:999px;align-items:center;gap:8px;padding:4px 10px 4px 4px;font-size:14px;font-weight:700;display:inline-flex}.tool-chrome-pill img{border-radius:8px}.tool-chrome-title{letter-spacing:-.02em;margin:0;font-size:1.25rem;font-weight:800}.hub-view-switcher{border:1px solid var(--border);background:var(--surface);border-radius:10px;flex-wrap:wrap;align-items:center;gap:4px;padding:3px;display:inline-flex}.hub-view-switcher-label{color:var(--text-muted);padding:0 6px;font-size:12px;font-weight:600}.hub-view-switcher-btn{appearance:none;font:inherit;color:var(--text-muted);cursor:pointer;white-space:nowrap;background:0 0;border:none;border-radius:8px;padding:5px 10px;font-size:13px;font-weight:700}.hub-view-switcher-btn:hover{color:var(--text);background:#f1f5f9}.hub-view-switcher-btn.is-active{background:var(--brand-soft,#eef2ff);color:var(--brand,#1f3a8a)}.roster-back,.tool-chrome-back{text-decoration:none}@media (max-width:640px){.hub-view-switcher-label{display:none}.hub-view-switcher-btn{padding:5px 8px;font-size:12px}.tool-chrome-title{order:3;width:100%}}