:root{--bg:#f4f7fb;--panel:#fff;--ink:#0f172a;--muted:#64748b;--line:#e2e8f0;--nav:#0b1635;--nav2:#13234f;--blue:#175cd3;--blue2:#0f4fb8;--good:#15803d;--bad:#b42318;--warn:#a15c00;--shadow:0 14px 40px rgba(15,23,42,.09)}*{box-sizing:border-box}html,body{margin:0;min-height:100%;font-family:Tahoma,"Segoe UI",Arial,sans-serif;background:var(--bg);color:var(--ink)}button,input,textarea{font:inherit}button{cursor:pointer}.hidden{display:none!important}.login-shell{min-height:100vh;display:grid;grid-template-columns:minmax(320px,500px) 1fr}.brand-side{background:linear-gradient(145deg,var(--nav),var(--nav2));color:#fff;display:flex;align-items:center;padding:64px}.brand-lockup{max-width:520px}.brand-mark{width:76px;height:76px;border:1px solid rgba(255,255,255,.3);border-radius:20px;display:grid;place-items:center;font-weight:800;font-size:24px;letter-spacing:2px;margin-bottom:26px;background:rgba(255,255,255,.06)}.brand-side h1{font-size:38px;line-height:1.35;margin:0 0 14px}.brand-side p{color:#cbd5e1;line-height:2;font-size:16px}.login-side{display:flex;align-items:center;justify-content:center;padding:30px}.login-card{width:min(440px,100%);background:var(--panel);border:1px solid var(--line);border-radius:22px;padding:30px;box-shadow:var(--shadow)}.login-card h2{margin:0 0 8px;font-size:24px}.login-card .sub{color:var(--muted);line-height:1.8;margin-bottom:24px}.field{margin:14px 0}.field label{display:block;font-size:13px;font-weight:700;margin-bottom:7px}.field input,.field textarea{width:100%;border:1px solid #cbd5e1;border-radius:11px;padding:12px 13px;outline:none;background:#fff}.field input:focus,.field textarea:focus{border-color:#6ea1ef;box-shadow:0 0 0 3px rgba(23,92,211,.1)}.captcha-row{display:flex;gap:10px;align-items:center}.captcha-box{flex:1;min-height:74px;border:1px solid var(--line);border-radius:11px;background:#f8fafc;overflow:hidden;display:grid;place-items:center}.captcha-box img{max-width:100%;display:block}.icon-btn{border:1px solid var(--line);background:#fff;border-radius:10px;padding:10px 12px;color:#334155}.primary{width:100%;border:0;border-radius:11px;background:var(--blue);color:#fff;padding:12px 16px;font-weight:700}.primary:hover{background:var(--blue2)}.primary:disabled{opacity:.55;cursor:not-allowed}.error-text{color:var(--bad);font-size:13px;min-height:20px;margin-top:10px}.security-note{margin-top:18px;border-top:1px solid var(--line);padding-top:14px;color:var(--muted);font-size:12px;line-height:1.8}.hp{position:absolute!important;width:1px!important;height:1px!important;padding:0!important;margin:-1px!important;overflow:hidden!important;clip:rect(0,0,0,0)!important;white-space:nowrap!important;border:0!important;opacity:0!important;pointer-events:none!important}.app-shell{height:100vh;display:grid;grid-template-columns:320px 1fr;background:#eef2f7}.sidebar{background:var(--nav);color:#fff;display:flex;flex-direction:column;min-width:0}.sidebar-head{padding:20px;border-bottom:1px solid rgba(255,255,255,.1)}.small-logo{display:flex;align-items:center;gap:10px}.small-logo b{font-size:18px;letter-spacing:.6px}.small-logo span{font-size:12px;color:#b7c4dc}.new-chat{margin-top:16px;width:100%;border:1px solid rgba(255,255,255,.25);color:#fff;background:rgba(255,255,255,.08);border-radius:11px;padding:11px}.new-chat:hover{background:rgba(255,255,255,.13)}.chat-list{overflow:auto;padding:10px;flex:1}.chat-item{width:100%;text-align:right;border:0;background:transparent;color:#dce5f4;border-radius:10px;padding:11px;margin:3px 0}.chat-item:hover,.chat-item.active{background:rgba(255,255,255,.11);color:#fff}.chat-item strong{display:block;font-size:13px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.chat-item small{display:block;color:#9fb0cc;margin-top:5px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.sidebar-foot{padding:14px 16px;border-top:1px solid rgba(255,255,255,.1)}.user-meta{display:flex;justify-content:space-between;gap:10px;align-items:center}.user-meta b{font-size:13px}.user-meta small{display:block;color:#aab8cf;margin-top:4px}.quota{background:#183366;border:1px solid #31518f;border-radius:999px;padding:5px 9px;font-size:12px;white-space:nowrap}.logout-link{width:100%;margin-top:10px;border:0;background:transparent;color:#9fb0cc;text-align:right;padding:6px 0}.main{min-width:0;display:flex;flex-direction:column}.topbar{height:74px;background:#fff;border-bottom:1px solid var(--line);padding:0 24px;display:flex;align-items:center;justify-content:space-between;gap:12px}.top-title{min-width:0}.top-title h2{font-size:17px;margin:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.top-title p{margin:5px 0 0;color:var(--muted);font-size:12px}.rename-btn{border:1px solid var(--line);background:#fff;border-radius:9px;padding:7px 10px;color:#475569}.conversation{flex:1;overflow:auto;padding:30px max(24px,calc((100% - 920px)/2))}.empty-state{height:100%;display:grid;place-items:center;text-align:center;color:var(--muted)}.empty-state .round{width:58px;height:58px;border-radius:18px;background:#e6eefb;color:var(--blue);display:grid;place-items:center;margin:0 auto 16px;font-size:22px;font-weight:800}.empty-state h3{color:var(--ink);margin:0 0 8px}.empty-state p{max-width:560px;line-height:2;margin:0}.bubble-row{display:flex;margin:14px 0}.bubble-row.user{justify-content:flex-start}.bubble-row.assistant{justify-content:flex-end}.bubble{max-width:min(760px,88%);border-radius:17px;padding:14px 16px;line-height:1.95;white-space:pre-wrap;word-break:break-word}.bubble-row.user .bubble{background:#dbeafe;border-bottom-left-radius:5px}.bubble-row.assistant .bubble{background:#fff;border:1px solid var(--line);box-shadow:0 3px 12px rgba(15,23,42,.04);border-bottom-right-radius:5px}.bubble.error{background:#fff1f2;border-color:#fecdd3;color:#881337}.bubble-meta{margin-top:8px;font-size:11px;color:#94a3b8}.feedback{display:flex;gap:7px;margin-top:9px}.feedback button{border:1px solid var(--line);background:#fff;border-radius:8px;padding:5px 8px;font-size:12px;color:#475569}.feedback button.selected{border-color:#93b4e8;background:#eff6ff;color:#174ea6}.composer-wrap{background:#fff;border-top:1px solid var(--line);padding:14px max(20px,calc((100% - 920px)/2)) 18px}.composer{display:flex;gap:10px;align-items:flex-end}.composer textarea{flex:1;resize:none;min-height:58px;max-height:150px;border:1px solid #cbd5e1;border-radius:14px;padding:13px;outline:none;line-height:1.7}.composer textarea:focus{border-color:#6ea1ef;box-shadow:0 0 0 3px rgba(23,92,211,.08)}.send-btn{width:96px;border:0;background:var(--blue);color:#fff;border-radius:12px;padding:13px}.composer-note{font-size:11px;color:var(--muted);margin-top:8px;display:flex;justify-content:space-between}.modal-back{position:fixed;inset:0;background:rgba(15,23,42,.48);display:grid;place-items:center;padding:20px;z-index:20}.modal{width:min(460px,100%);background:#fff;border-radius:18px;padding:24px;box-shadow:var(--shadow)}.modal h3{margin-top:0}.modal-actions{display:flex;gap:8px;justify-content:flex-end;margin-top:18px}.secondary{border:1px solid var(--line);background:#fff;border-radius:9px;padding:9px 13px}.danger{color:var(--bad)}.admin-shell{min-height:100vh;background:#f5f7fb}.admin-head{background:var(--nav);color:#fff;padding:18px 28px;display:flex;justify-content:space-between;align-items:center}.admin-head h1{font-size:18px;margin:0}.admin-head .admin-nav{display:flex;gap:8px}.admin-head button{border:1px solid rgba(255,255,255,.25);background:transparent;color:#fff;border-radius:8px;padding:8px 10px}.admin-wrap{max-width:1280px;margin:24px auto;padding:0 18px}.admin-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}.metric{background:#fff;border:1px solid var(--line);border-radius:14px;padding:16px}.metric span{font-size:12px;color:var(--muted)}.metric b{display:block;font-size:22px;margin-top:8px}.admin-card{background:#fff;border:1px solid var(--line);border-radius:15px;margin-top:16px;overflow:hidden}.card-head{padding:14px 16px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;gap:10px}.card-head h3{margin:0;font-size:15px}.card-body{padding:16px}.table-wrap{overflow:auto}.table{width:100%;border-collapse:collapse;min-width:820px}.table th,.table td{text-align:right;padding:10px;border-bottom:1px solid #eef2f6;font-size:12px;vertical-align:top}.table th{color:#64748b;background:#f8fafc;position:sticky;top:0}.tag{display:inline-block;border-radius:999px;padding:3px 8px;font-size:11px;background:#eef2ff;color:#3730a3}.tag.good{background:#ecfdf3;color:#166534}.tag.bad{background:#fff1f2;color:#9f1239}.tag.warn{background:#fffbeb;color:#92400e}.admin-actions{display:flex;gap:5px;flex-wrap:wrap}.admin-actions button{border:1px solid var(--line);background:#fff;border-radius:7px;padding:5px 7px;font-size:11px}.admin-toolbar{display:flex;gap:8px;flex-wrap:wrap}.admin-toolbar button,.admin-toolbar a{border:1px solid var(--line);background:#fff;border-radius:8px;padding:8px 10px;text-decoration:none;color:#334155;font-size:12px}.security-banner{border-radius:12px;padding:12px 14px;margin:12px 0;font-size:13px}.security-banner.pass{background:#ecfdf3;color:#166534;border:1px solid #bbf7d0}.security-banner.blocked{background:#fff1f2;color:#9f1239;border:1px solid #fecdd3}.question-cell{max-width:330px;white-space:pre-wrap;line-height:1.65}.answer-cell{max-width:420px;white-space:pre-wrap;line-height:1.65}.temp-pass{direction:ltr;font-family:Consolas,monospace;background:#0f172a;color:#fff;border-radius:8px;padding:9px;margin-top:8px;word-break:break-all}@media(max-width:900px){.login-shell{grid-template-columns:1fr}.brand-side{display:none}.app-shell{grid-template-columns:1fr}.sidebar{position:fixed;z-index:15;width:300px;height:100vh;right:-310px;transition:.2s}.sidebar.open{right:0}.topbar{padding:0 14px}.mobile-menu{display:block!important}.admin-grid{grid-template-columns:repeat(2,1fr)}}@media(min-width:901px){.mobile-menu{display:none!important}}@media(max-width:560px){.admin-grid{grid-template-columns:1fr 1fr}.conversation{padding:20px 12px}.composer-wrap{padding:10px 12px}.bubble{max-width:94%}.brand-side{padding:30px}.login-side{padding:14px}.login-card{padding:22px}}

.muted-copy{color:#64748b;line-height:1.8}.muted-small{color:#64748b;font-size:11px;margin-top:4px}.auto-width{width:auto!important}

.topbar-left{display:flex;gap:10px;align-items:center;min-width:0}

/* =====================================================================
   v0.7.4 Responsive stability layer
   UI-only: answer engine / knowledge behavior remains untouched.
   Desktop: fixed right sidebar + fixed composer; conversation alone scrolls.
   Mobile: sidebar becomes a fixed drawer; composer remains pinned to bottom.
   ===================================================================== */
:root{
  --sidebar-w:320px;
  --topbar-h:74px;
  --composer-h:104px;
  --safe-bottom:env(safe-area-inset-bottom,0px);
  --safe-top:env(safe-area-inset-top,0px);
}
html,body{width:100%;height:100%;min-height:100%;max-width:100%;overflow-x:hidden}
body{min-height:100vh;min-height:100svh;background:var(--bg)}

/* Login must remain visible and centered after live viewport/orientation changes. */
.login-shell{
  width:100%;
  min-height:100vh;
  min-height:100svh;
  display:grid;
  grid-template-columns:minmax(320px,500px) minmax(0,1fr);
  overflow:auto;
}
.login-side{
  width:100%;
  min-width:0;
  min-height:100vh;
  min-height:100svh;
  display:flex;
  align-items:center;
  justify-content:center;
}
.login-card{display:block;max-width:440px}

/* Application viewport. The shell never scrolls; only .conversation does. */
.app-shell{
  position:fixed;
  inset:0;
  width:100%;
  height:100vh;
  height:100dvh;
  display:block;
  background:#eef2f7;
  overflow:hidden;
}
.sidebar{
  position:fixed;
  z-index:40;
  top:0;
  right:0;
  bottom:0;
  width:var(--sidebar-w);
  height:100vh;
  height:100dvh;
  min-width:0;
  overflow:hidden;
  box-shadow:-1px 0 0 rgba(255,255,255,.03);
}
.sidebar-head{flex:0 0 auto;padding-top:max(20px,var(--safe-top))}
.chat-list{min-height:0;overflow-y:auto;overscroll-behavior:contain;-webkit-overflow-scrolling:touch}
.sidebar-foot{flex:0 0 auto;padding-bottom:max(14px,calc(10px + var(--safe-bottom)))}
.main{
  position:fixed;
  z-index:1;
  top:0;
  right:var(--sidebar-w);
  bottom:0;
  left:0;
  height:auto;
  min-width:0;
  overflow:hidden;
  display:block;
  background:#eef2f7;
}
/* These three are absolute INSIDE .main. This is deliberately more stable
   than viewport-fixed children when Chrome switches device emulation live. */
.topbar{
  position:absolute;
  z-index:25;
  top:0;
  right:0;
  left:0;
  height:var(--topbar-h);
  min-height:var(--topbar-h);
  padding-top:var(--safe-top);
  background:rgba(255,255,255,.98);
  backdrop-filter:saturate(150%) blur(8px);
}
.conversation{
  position:absolute;
  z-index:2;
  top:var(--topbar-h);
  right:0;
  bottom:var(--composer-h);
  left:0;
  min-height:0;
  overflow-y:auto;
  overflow-x:hidden;
  overscroll-behavior-y:contain;
  -webkit-overflow-scrolling:touch;
  scroll-behavior:smooth;
  padding:30px max(24px,calc((100% - 920px)/2));
  scrollbar-gutter:stable;
}
.empty-state{min-height:100%;height:auto;padding:20px}
.composer-wrap{
  position:absolute;
  z-index:30;
  right:0;
  bottom:0;
  left:0;
  width:auto;
  padding:12px max(20px,calc((100% - 920px)/2)) max(12px,calc(10px + var(--safe-bottom)));
  background:rgba(255,255,255,.98);
  backdrop-filter:saturate(150%) blur(10px);
  box-shadow:0 -8px 24px rgba(15,23,42,.045);
}
.composer{max-width:920px;margin-inline:auto}
.composer-note{max-width:920px;margin:8px auto 0;gap:12px}
.composer textarea{min-width:0;min-height:56px;height:56px;max-height:132px;overflow-y:auto;touch-action:manipulation}
.send-btn{flex:0 0 88px;min-height:48px}
.sidebar-backdrop{display:none}
.chat-item.active{background:rgba(255,255,255,.16);color:#fff;box-shadow:inset -3px 0 0 #7fb0ff}
.chat-item[aria-current="true"]{background:rgba(255,255,255,.16);color:#fff;box-shadow:inset -3px 0 0 #7fb0ff}

/* Admin remains responsive without changing its behavior. */
.admin-head{position:sticky;top:0;z-index:10;padding-top:max(18px,var(--safe-top))}
.admin-wrap{padding-bottom:max(24px,calc(16px + var(--safe-bottom)))}
.table-wrap{-webkit-overflow-scrolling:touch;overscroll-behavior-x:contain}

@media (max-width:1100px) and (min-width:901px){
  :root{--sidebar-w:280px}
  .conversation{padding-inline:20px}
  .composer-wrap{padding-inline:20px}
}

@media(max-width:900px){
  :root{--sidebar-w:min(86vw,320px);--topbar-h:68px}
  .login-shell{display:block!important;min-height:100vh;min-height:100svh}
  .brand-side{display:none!important}
  .login-side{
    display:flex!important;
    width:100%!important;
    min-height:100vh!important;
    min-height:100svh!important;
    padding:18px!important;
    align-items:center!important;
    justify-content:center!important;
  }
  .login-card{display:block!important;width:min(100%,440px)!important;margin:auto!important}
  .app-shell{display:block}
  .main{right:0}
  .topbar{padding-inline:12px}
  .conversation{padding:20px clamp(12px,3vw,22px)}
  .composer-wrap{padding-inline:clamp(10px,3vw,18px)}
  .sidebar{
    width:var(--sidebar-w);
    right:0;
    transform:translate3d(105%,0,0);
    transition:transform .22s ease;
    box-shadow:-14px 0 35px rgba(5,15,40,.28);
    will-change:transform;
  }
  .sidebar.open{transform:translate3d(0,0,0)}
  .sidebar-backdrop{
    display:block;
    position:fixed;
    z-index:35;
    inset:0;
    border:0;
    padding:0;
    margin:0;
    background:rgba(7,16,38,.45);
    opacity:0;
    pointer-events:none;
    transition:opacity .2s ease;
  }
  body.sidebar-open .sidebar-backdrop{opacity:1;pointer-events:auto}
  body.sidebar-open{overflow:hidden}
  .mobile-menu{display:block!important;flex:0 0 auto}
  .top-title p{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:min(62vw,520px)}
  .rename-btn{flex:0 0 auto}
  .bubble{max-width:min(92%,720px)}
  .admin-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .admin-head{gap:10px;flex-wrap:wrap;padding-inline:16px}
  .admin-wrap{margin-top:16px;padding-inline:12px}
  .card-head{align-items:flex-start;flex-wrap:wrap}
}

@media(min-width:901px){.mobile-menu{display:none!important}}

@media(max-width:600px){
  :root{--topbar-h:64px}
  .login-side{padding:12px!important}
  .login-card{padding:20px;border-radius:17px}
  .topbar{padding-inline:10px;gap:8px}
  .top-title h2{font-size:15px}
  .top-title p{font-size:10px;margin-top:3px;max-width:54vw}
  .rename-btn{font-size:12px;padding:6px 8px}
  .conversation{padding:16px 10px}
  .bubble-row{margin:10px 0}
  .bubble{max-width:94%;padding:11px 12px;border-radius:14px;line-height:1.85;font-size:13px}
  .bubble-meta{font-size:10px}
  .feedback{flex-wrap:wrap}
  .feedback button{min-height:34px}
  .composer-wrap{padding:8px 8px max(8px,calc(6px + var(--safe-bottom)))}
  .composer{gap:7px}
  .composer textarea{min-height:50px;height:50px;max-height:112px;padding:11px 12px;font-size:16px;border-radius:12px}
  .send-btn{flex-basis:72px;width:72px;min-height:46px;padding:10px 7px}
  .composer-note{font-size:9px;gap:8px;flex-wrap:wrap;margin-top:5px}
  .composer-note span:first-child{display:none}
  .sidebar-head{padding-inline:14px}
  .sidebar-foot{padding-inline:14px}
  .chat-list{padding-inline:8px}
  .admin-grid{grid-template-columns:1fr}
  .metric{padding:13px}
  .metric b{font-size:19px}
  .admin-head h1{font-size:15px}
  .admin-head .admin-nav{width:100%;justify-content:flex-start}
  .admin-card{border-radius:12px}
  .card-head{padding:12px}
  .admin-toolbar{width:100%}
  .admin-toolbar button,.admin-toolbar a{flex:1;text-align:center;min-width:135px}
  .modal-back{padding:12px}
  .modal{padding:18px;border-radius:15px;max-height:calc(100dvh - 24px);overflow:auto}
}

@media(max-width:380px){
  .small-logo span{display:none}
  .top-title p{display:none}
  .rename-btn{max-width:90px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
  .composer textarea{font-size:16px}
  .send-btn{flex-basis:64px;width:64px}
}

@media(max-height:540px) and (orientation:landscape){
  :root{--topbar-h:56px}
  .login-side{align-items:flex-start!important;padding-block:10px!important}
  .topbar{height:56px;min-height:56px}
  .top-title p{display:none}
  .composer-wrap{padding-top:6px;padding-bottom:max(6px,var(--safe-bottom))}
  .composer textarea{min-height:42px;height:42px;max-height:78px}
  .send-btn{min-height:42px}
  .composer-note{display:none}
  .sidebar-head{padding-top:10px;padding-bottom:10px}
  .new-chat{margin-top:8px;padding:8px}
  .sidebar-foot{padding-top:8px}
}

@media(prefers-reduced-motion:reduce){
  .sidebar,.sidebar-backdrop{transition:none!important}
  .conversation{scroll-behavior:auto}
}


/* v0.7.5 login transition stability: login stays anchored to the visible viewport. */
@media(max-width:900px){
  body:not(.app-active) .login-shell{
    position:fixed;
    inset:0;
    width:100%;
    height:100vh;
    height:100dvh;
    min-height:0!important;
    overflow-y:auto;
    overflow-x:hidden;
    z-index:100;
    background:var(--bg);
  }
  body:not(.app-active) .login-side{
    min-height:100%!important;
    height:auto;
    padding:max(12px,var(--safe-top)) 12px max(12px,var(--safe-bottom))!important;
  }
}

/* Final visibility invariant: responsive rules must never resurrect hidden views. */
.hidden{display:none!important}