:root{--brand: #0a5ef3;--brand-dark: #0949c2;--brand-tint: #eaf1fe;--text: #14171f;--muted: #949da6;--border: #d5dee3;--surface: #ffffff;--bg: #f7f9fb;--danger: #e14949;--warn: #b26a00;color-scheme:light}*{box-sizing:border-box}html,body,#root{height:100%;margin:0}body{background:var(--bg);color:var(--text);font:15px/1.5 Poppins,system-ui,-apple-system,Segoe UI,sans-serif}code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.9em;color:var(--muted)}.page{min-height:100%;display:grid;place-items:center;padding:24px}.card{width:100%;max-width:460px;background:var(--surface);border:1px solid var(--border);border-radius:14px;padding:28px;box-shadow:0 1px 2px #14171f0a}.card h1{margin:4px 0 12px;font-size:22px;font-weight:600}.muted{color:#6b7280}.small{font-size:13px}.actions,.frame__actions{display:flex;gap:10px;align-items:center;margin-top:20px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;background:var(--surface);border:1px solid var(--border);border-radius:8px;color:var(--text);padding:11px 16px;font:inherit;cursor:pointer;text-decoration:none}.btn:hover:not(:disabled){background:#f3f4f6}.btn:disabled{opacity:.55;cursor:default}.btn--primary{background:var(--brand);border-color:var(--brand);color:#fff;font-weight:600}.btn--primary:hover:not(:disabled){background:var(--brand-dark);border-color:var(--brand-dark)}.btn--small{padding:6px 12px;font-size:13px}.notice{margin:16px 0 0;padding:12px 14px;border-radius:10px;border:1px solid var(--border);font-size:14px}.notice p{margin:0 0 6px}.notice p:last-child{margin-bottom:0}.notice--error{border-color:#f3c9c9;background:#fdf2f2;color:#962c2c}.classroom{height:100%}.frame{position:relative;height:100%;width:100%;background:#fff}.frame__iframe{display:block;height:100%;width:100%;border:0}.frame__overlay{position:absolute;top:0;right:0;bottom:0;left:0;display:grid;place-items:center;background:#fff}.frame__card{max-width:400px;text-align:center;padding:24px}.frame__card h3{margin:0 0 8px;font-size:18px;font-weight:600}.frame__card p{color:#6b7280;margin:0}.frame__actions{justify-content:center}.spinner{width:90px;height:90px;border:8px solid #e9eaee;border-top-color:var(--brand);border-radius:50%;animation:spin 1s linear infinite}.loading-screen{min-height:100%;display:grid;place-items:center;background:#fff}@keyframes spin{to{transform:rotate(360deg)}}.feed{position:absolute;left:12px;bottom:12px;width:300px;background:#fffe;border:1px solid var(--border);border-radius:10px;font-size:12px;overflow:hidden;box-shadow:0 2px 8px #14171f14}.feed__toggle{width:100%;background:transparent;border:0;color:#6b7280;font:inherit;padding:8px 10px;text-align:left;cursor:pointer}.feed__status{display:grid;grid-template-columns:1fr 1fr;gap:4px 10px;margin:0;padding:8px 10px;border-top:1px solid var(--border)}.feed__stat{display:flex;justify-content:space-between;gap:8px}.feed__stat dt{color:var(--muted)}.feed__stat dd{margin:0}.feed__warn{margin:0;padding:8px 10px;border-top:1px solid var(--border);background:#fdf8ec;color:var(--warn);line-height:1.4}.feed__list{list-style:none;margin:0;padding:8px 10px;max-height:190px;overflow-y:auto;border-top:1px solid var(--border)}.feed__list li{display:flex;justify-content:space-between;gap:8px;padding:2px 0}.feed__list span{color:var(--muted)}.notfound{min-height:100%;display:grid;place-items:center;padding:24px;text-align:center}.notfound__code{margin:0;font-size:64px;line-height:1;font-weight:700;color:var(--brand)}.notfound h1{margin:12px 0 6px;font-size:20px;font-weight:600}.notfound p{margin:0;color:#6b7280}