:root{
  --bg:#f7f9fd;--ink:#0f172a;--muted:#64748b;--card:#fff;--line:#e2e8f0;
  --brand:#2563eb;--brand2:#7c3aed;--cyan:#06b6d4;--good:#16a34a;--warn:#f59e0b;--red:#dc2626;
  --soft:#eef4ff;--soft2:#f5f3ff;--radius:24px;--radius2:18px;--shadow:0 22px 70px rgba(15,23,42,.10);--shadow2:0 12px 35px rgba(15,23,42,.08)
}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Inter,Manrope,ui-sans-serif,system-ui,Segoe UI,Arial,sans-serif;background:radial-gradient(circle at 8% -6%,rgba(37,99,235,.18),transparent 32%),radial-gradient(circle at 90% 0,rgba(124,58,237,.16),transparent 30%),linear-gradient(180deg,#f8fbff,#f7f9fd);color:var(--ink);font-size:15px}a{text-decoration:none;color:inherit}button,input,textarea,select{font:inherit}.app-shell{display:grid;grid-template-columns:292px minmax(0,1fr);min-height:100vh}.sidebar{position:sticky;top:0;height:100vh;background:linear-gradient(180deg,#0f172a,#111827);color:#fff;padding:20px;display:flex;flex-direction:column;gap:18px;overflow:auto}.brand-block{display:flex;align-items:center;gap:12px}.brand-logo{width:46px;height:46px;border-radius:18px;background:linear-gradient(135deg,var(--brand),var(--brand2));display:grid;place-items:center;color:#fff;font-weight:950;font-size:26px;box-shadow:0 18px 36px rgba(37,99,235,.32)}.brand-block b{display:block;letter-spacing:-.04em;font-size:20px}.brand-block small{display:block;color:#94a3b8;font-size:12px;margin-top:2px}.side-nav{display:flex;flex-direction:column;gap:6px;margin-top:8px}.side-nav a{position:relative;display:flex;align-items:center;gap:10px;padding:13px 14px;border-radius:16px;color:#cbd5e1;font-weight:850;transition:.18s}.side-nav a:hover,.side-nav a.active{background:rgba(255,255,255,.1);color:#fff;transform:translateX(2px)}.side-nav a.active:before{content:"";position:absolute;left:0;top:12px;bottom:12px;width:4px;border-radius:8px;background:linear-gradient(var(--brand),var(--brand2))}.side-card{margin-top:auto;border:1px solid rgba(255,255,255,.12);background:rgba(255,255,255,.08);border-radius:22px;padding:18px;display:grid;gap:7px}.side-card span{font-size:26px}.side-card b{display:block}.side-card small{color:#cbd5e1;line-height:1.5}.main-panel{min-width:0}.topbar{height:78px;display:flex;align-items:center;justify-content:space-between;gap:18px;padding:0 30px;background:rgba(255,255,255,.78);backdrop-filter:blur(18px);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}.mobile-menu{display:none}.topbar h4{margin:2px 0 0;font-size:18px;letter-spacing:-.03em}.crumb{font-size:12px;color:var(--muted);font-weight:900;text-transform:uppercase;letter-spacing:.08em}.top-search{flex:1;max-width:420px;position:relative}.top-search input{height:44px;border-radius:999px;padding-left:44px;background:#fff}.top-search:before{content:"⌕";position:absolute;left:17px;top:9px;color:#64748b;font-size:22px;z-index:1}.top-actions{display:flex;align-items:center;gap:10px}.icon-btn,.user-chip,.logout{border:1px solid var(--line);background:#fff;border-radius:999px;padding:10px 13px;font-weight:850;color:#334155;box-shadow:0 8px 20px rgba(15,23,42,.04)}.logout{color:#dc2626}.public-top{height:76px;display:flex;align-items:center;justify-content:space-between;padding:0 28px;background:rgba(255,255,255,.86);backdrop-filter:blur(15px);border-bottom:1px solid var(--line);box-shadow:0 8px 24px rgba(15,23,42,.04)}.public-top nav{display:flex;align-items:center;gap:16px}.wrap{max-width:1240px;margin:0 auto;padding:30px 24px 80px}.public-wrap{max-width:1180px}.card{background:rgba(255,255,255,.92);border:1px solid var(--line);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow2);backdrop-filter:blur(10px);margin-bottom:20px}.glass{background:linear-gradient(135deg,rgba(255,255,255,.96),rgba(239,246,255,.88))}.mini{padding:20px;transition:.18s}.mini:hover{transform:translateY(-4px);box-shadow:var(--shadow)}h1{font-size:46px;letter-spacing:-.065em;margin:0 0 14px;line-height:1.05}h2{font-size:25px;letter-spacing:-.045em;margin:0 0 14px}h3{margin:18px 0 10px;letter-spacing:-.025em}.muted{color:var(--muted);line-height:1.7}.grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:18px}.grid3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.grid2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff;border:0;border-radius:16px;padding:13px 18px;text-decoration:none;font-weight:950;cursor:pointer;box-shadow:0 14px 30px rgba(37,99,235,.24);transition:.18s}.btn:hover{transform:translateY(-2px);box-shadow:0 18px 40px rgba(37,99,235,.30)}.btn.small{padding:10px 14px;border-radius:999px}.btn.secondary{background:#eef2ff;color:#1d4ed8;box-shadow:none}.btn.ghost{background:#fff;color:#111;border:1px solid var(--line);box-shadow:none}.btn.success{background:linear-gradient(135deg,#16a34a,#22c55e)}input,textarea,select{width:100%;border:1px solid var(--line);border-radius:18px;padding:14px 16px;background:#fff;color:var(--ink);outline:none;transition:.16s}input:focus,textarea:focus,select:focus{border-color:#93c5fd;box-shadow:0 0 0 4px rgba(37,99,235,.10)}textarea{min-height:150px;resize:vertical}label{font-weight:850;display:block;margin:12px 0 8px}.alert{padding:18px;border-radius:18px;background:#fff;border:1px solid var(--line);margin:18px 0}.error{color:var(--red);border-color:#fecaca;background:#fff7f7}.success{color:var(--good);border-color:#bbf7d0;background:#f0fdf4}.menu{display:flex;gap:12px;flex-wrap:wrap}.pill{display:inline-flex;align-items:center;gap:6px;border-radius:999px;background:#eef2ff;color:#1d4ed8;padding:8px 12px;font-weight:950;margin:5px 6px 5px 0;font-size:12px}.progressbar{height:12px;background:#e2e8f0;border-radius:999px;overflow:hidden}.progressbar span{display:block;height:100%;background:linear-gradient(90deg,var(--brand),var(--brand2));width:0;border-radius:999px}.footer{text-align:center;color:var(--muted);padding:24px}.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.stat{border:1px solid var(--line);background:#fff;border-radius:18px;padding:16px}.stat b{font-size:24px;display:block;letter-spacing:-.04em}.teacher{display:flex;gap:14px;align-items:flex-start}.avatar{width:54px;height:54px;border-radius:20px;background:linear-gradient(135deg,#2563eb,#7c3aed);display:flex;align-items:center;justify-content:center;color:#fff;font-size:24px;flex:0 0 auto;box-shadow:0 15px 34px rgba(37,99,235,.28)}.bubble{background:#f8fafc;border:1px solid var(--line);border-radius:22px;padding:18px;flex:1}.choice{padding:16px;border:1px solid var(--line);border-radius:18px;margin:10px 0;background:#fff;cursor:pointer}.choice:hover{border-color:#2563eb}.ai-output{line-height:1.78}.dashboard-hero{display:grid;grid-template-columns:1.2fr .8fr;gap:20px;align-items:stretch}.welcome-card{position:relative;overflow:hidden;min-height:310px;background:linear-gradient(135deg,#0f172a,#1e3a8a 52%,#6d28d9);color:#fff}.welcome-card:after{content:"";position:absolute;right:-120px;bottom:-120px;width:330px;height:330px;border-radius:50%;background:rgba(255,255,255,.13)}.welcome-card .muted{color:#dbeafe}.welcome-card .pill{background:rgba(255,255,255,.14);color:#fff;border:1px solid rgba(255,255,255,.14)}.welcome-content{position:relative;z-index:1}.progress-ring{width:148px;height:148px;border-radius:50%;display:grid;place-items:center;background:conic-gradient(var(--brand) calc(var(--p)*1%),#e2e8f0 0);margin:auto}.progress-ring-inner{width:112px;height:112px;border-radius:50%;background:#fff;display:grid;place-items:center;text-align:center}.progress-ring b{font-size:30px;letter-spacing:-.05em}.dash-kpis{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px}.dash-kpi{position:relative;overflow:hidden}.dash-kpi .icon{width:42px;height:42px;border-radius:15px;display:grid;place-items:center;background:#eef2ff;margin-bottom:14px;font-size:22px}.dash-kpi strong{font-size:34px;letter-spacing:-.06em}.quick-action{display:flex;align-items:center;gap:14px}.quick-action .icon{width:50px;height:50px;border-radius:18px;background:linear-gradient(135deg,#eff6ff,#f5f3ff);display:grid;place-items:center;font-size:24px}.journey{display:grid;gap:11px}.journey-step{display:flex;align-items:center;gap:12px;padding:14px;border:1px solid var(--line);border-radius:18px;background:#fff;transition:.16s}.journey-step:hover{transform:translateX(3px);border-color:#bfdbfe}.journey-step strong{display:block}.circle{width:36px;height:36px;border-radius:50%;display:grid;place-items:center;background:#eef2ff;color:#1d4ed8;font-weight:950}.lesson-shell{display:grid;grid-template-columns:280px 1fr;gap:22px}.lesson-side{position:sticky;top:100px;align-self:start}.step-card{display:none}.step-card.active{display:block;animation:pop .28s ease}@keyframes pop{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}.chat-layout{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:20px}.chat-panel{padding:0;overflow:hidden}.chat-header{padding:22px 24px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;background:linear-gradient(135deg,#fff,#f8fbff)}.chatbox{height:62vh;overflow:auto;padding:24px;background:linear-gradient(180deg,#f8fafc,#fff);display:flex;flex-direction:column;gap:16px}.chat-row{display:flex;gap:12px;align-items:flex-start}.chat-row.user{justify-content:flex-end}.chat-avatar{width:38px;height:38px;border-radius:14px;display:grid;place-items:center;background:#eef2ff;flex:0 0 auto}.chat-bubble{max-width:78%;padding:15px 17px;border-radius:20px;line-height:1.62;box-shadow:0 10px 24px rgba(15,23,42,.06)}.chat-row.ai .chat-bubble{background:#fff;border:1px solid var(--line);border-top-left-radius:8px}.chat-row.user .chat-bubble{background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff;border-top-right-radius:8px}.chat-compose{padding:18px;border-top:1px solid var(--line);background:#fff}.compose-box{display:grid;grid-template-columns:1fr auto;gap:12px}.compose-box textarea{min-height:58px;max-height:150px}.typing{display:inline-flex;gap:4px;align-items:center}.typing i{width:7px;height:7px;border-radius:50%;background:#64748b;animation:bounce 1s infinite}.typing i:nth-child(2){animation-delay:.15s}.typing i:nth-child(3){animation-delay:.3s}@keyframes bounce{0%,80%,100%{transform:scale(.7);opacity:.5}40%{transform:scale(1);opacity:1}}.floating-ai{position:fixed;right:24px;bottom:24px;width:58px;height:58px;border-radius:22px;background:linear-gradient(135deg,var(--brand),var(--brand2));display:grid;place-items:center;color:#fff;font-size:24px;box-shadow:0 18px 45px rgba(37,99,235,.35);z-index:30}.loading-note{display:none;margin-top:12px;padding:12px 14px;border-radius:14px;background:#eef4ff;color:#1846b8;font-weight:850}form.is-loading .loading-note{display:block}form.is-loading button[type=submit],form.is-loading .btn{opacity:.75;pointer-events:none}.spinner{display:inline-block;width:14px;height:14px;border:2px solid rgba(24,70,184,.25);border-top-color:#1846b8;border-radius:50%;animation:spin .8s linear infinite;margin-right:8px;vertical-align:-2px}@keyframes spin{to{transform:rotate(360deg)}}.public-wrap{max-width:1180px}.eyebrow{display:inline-flex;align-items:center;gap:8px;background:#eef2ff;color:#3730a3;border:1px solid #ddd6fe;border-radius:999px;padding:8px 12px;font-weight:950;font-size:12px;text-transform:uppercase;letter-spacing:.08em;margin-bottom:16px}.landing-hero{display:grid;grid-template-columns:1.08fr .92fr;gap:28px;align-items:center;min-height:520px}.hero-copy h1{font-size:64px;max-width:680px}.muted.big{font-size:18px;max-width:640px}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin:26px 0}.trust-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:20px}.trust-row span{background:#fff;border:1px solid var(--line);border-radius:999px;padding:10px 13px;font-weight:850;color:#334155}.hero-preview{padding:24px}.lesson-preview-card{background:#fff;border:1px solid var(--line);border-radius:22px;padding:20px;margin:18px 0}.lesson-preview-card span{font-size:12px;font-weight:950;color:var(--brand);text-transform:uppercase;letter-spacing:.08em}.landing-features{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;margin-top:10px}.feature-icon{font-size:34px;display:inline-block;margin-bottom:10px}.auth-page{display:grid;grid-template-columns:1fr 480px;gap:28px;align-items:stretch;min-height:560px}.auth-page.reverse{grid-template-columns:500px 1fr}.auth-card{padding:32px}.auth-visual{padding:34px;overflow:hidden;position:relative}.auth-visual:after{content:"";position:absolute;right:-90px;bottom:-90px;width:260px;height:260px;border-radius:50%;background:linear-gradient(135deg,rgba(37,99,235,.16),rgba(124,58,237,.18));filter:blur(2px)}.auth-head{display:flex;gap:16px;align-items:flex-start;margin-bottom:20px}.auth-head h1{font-size:42px;margin-bottom:4px}.auth-icon{width:54px;height:54px;border-radius:19px;display:grid;place-items:center;background:linear-gradient(135deg,#eff6ff,#f5f3ff);border:1px solid var(--line);font-size:24px;flex:0 0 auto}.auth-btn{width:100%;margin-top:18px;padding:15px 18px}.auth-switch{text-align:center;color:var(--muted);margin:22px 0 0}.auth-switch a{color:var(--brand);font-weight:950}.auth-points{display:grid;gap:14px;margin-top:26px}.auth-points div{display:grid;grid-template-columns:42px 1fr;gap:2px 12px;background:rgba(255,255,255,.72);border:1px solid var(--line);border-radius:20px;padding:15px}.auth-points span{grid-row:1/3;width:42px;height:42px;border-radius:15px;background:#eef2ff;display:grid;place-items:center;font-size:22px}.auth-points b{display:block}.auth-points small{color:var(--muted);line-height:1.5}.feature-grid-mini{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin-top:24px}.feature-grid-mini div{background:#fff;border:1px solid var(--line);border-radius:20px;padding:18px;font-size:24px}.feature-grid-mini b{display:block;font-size:14px;margin-top:8px}.auth-page input{padding:16px 18px;border-radius:17px}.auth-page label{margin-top:14px}
@media(max-width:1100px){.dash-kpis{grid-template-columns:repeat(2,1fr)}.chat-layout,.dashboard-hero{grid-template-columns:1fr}.chatbox{height:56vh}}
@media(max-width:980px){.app-shell{grid-template-columns:1fr}.sidebar{position:fixed;z-index:50;left:-310px;width:292px;height:100vh;transition:.2s}.sidebar.open{left:0}.mobile-menu{display:inline-flex}.topbar{position:sticky;padding:0 16px}.top-search{display:none}.side-card{display:none}.landing-hero,.landing-features,.auth-page,.auth-page.reverse,.lesson-shell,.grid,.grid3,.grid2{grid-template-columns:1fr;min-height:auto}.wrap{padding:22px 14px 80px}.card{padding:18px}h1{font-size:34px}.lesson-side{position:static}.stats{grid-template-columns:1fr}.top-actions{gap:6px}.user-chip{display:none}.hero-copy h1{font-size:42px}.auth-card,.auth-visual{padding:22px}.auth-head h1{font-size:34px}.public-top{padding:0 16px}.public-top .brand-block small{display:none}.public-top nav{gap:10px}.trust-row span{font-size:13px}.landing-features{margin-top:0}.chat-bubble{max-width:88%}.dash-kpis{grid-template-columns:1fr}.compose-box{grid-template-columns:1fr}.floating-ai{right:16px;bottom:16px}}

/* v11 Chat management */
.chat-actions{display:flex;gap:10px;align-items:center;flex-wrap:wrap;justify-content:flex-end}
.inline-form{display:inline-flex;margin:0}
.btn.ghost{background:#fff;color:#334155;border:1px solid #dbe3f0;box-shadow:none}
.btn.ghost:hover{background:#f8fafc;transform:translateY(-1px)}
.btn.danger{background:#fff1f2;color:#dc2626;border:1px solid #fecdd3;box-shadow:none;width:100%;justify-content:center}
.btn.danger:hover{background:#ffe4e6}
.chat-history{display:flex;flex-direction:column;gap:10px;margin-top:10px;max-height:330px;overflow:auto;padding-right:4px}
.chat-history-item{display:block;text-decoration:none;color:#172033;background:#fff;border:1px solid #e3e9f5;border-radius:18px;padding:13px 14px;transition:.18s ease}
.chat-history-item:hover{transform:translateY(-1px);box-shadow:0 10px 28px rgba(15,23,42,.08);border-color:#cbd8ff}
.chat-history-item.active{border-color:#6d5dfc;background:linear-gradient(135deg,#eef3ff,#f6f1ff)}
.chat-history-item strong{display:block;font-size:14px;line-height:1.25;margin-bottom:5px}
.chat-history-item small{display:block;font-size:12px;line-height:1.35;color:#64748b}
.topic-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:10px}
.topic-chip{border:1px solid #e3e9f5;background:#fff;border-radius:16px;padding:12px 10px;font-weight:800;color:#172033;cursor:pointer;transition:.18s ease;text-align:left}
.topic-chip:hover{border-color:#6d5dfc;background:#f5f7ff;transform:translateY(-1px)}
@media(max-width:900px){.chat-actions{justify-content:flex-start}.chat-actions .btn{padding:11px 14px}.topic-grid{grid-template-columns:1fr}}