:root{
    --bg:#f6f7fb;--surface:#fff;--border:#e5e7ef;--text:#14172b;--muted:#6b7280;
    --primary:#4f46e5;--primary-dark:#4338ca;--primary-soft:#eef0ff;--primary-text:#4338ca;
    --danger:#dc2626;--danger-soft:#fef2f2;--ok:#059669;--ok-soft:#ecfdf5;
    --input-bg:#fff;--glow1:#dfe3ff;--glow2:#e9ddff;
    --active-border:#d6d9ff;--error-border:#fecaca;
    --radius:12px;--shadow:0 8px 30px rgba(20,23,43,.08);
    color-scheme:light;
    font-family:Inter,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
}
[data-theme="dark"]{
    --bg:#0d0f1a;--surface:#161a2b;--border:#262b42;--text:#e8eaf6;--muted:#9aa1b9;
    --primary:#6366f1;--primary-dark:#5558e6;--primary-soft:#23264a;--primary-text:#a5b4fc;
    --danger:#f87171;--danger-soft:#2d1517;--ok:#34d399;--ok-soft:#0f2a22;
    --input-bg:#101322;--glow1:#1d2050;--glow2:#2a1b4d;
    --active-border:#3a3f7a;--error-border:#5c2326;
    --shadow:0 8px 30px rgba(0,0,0,.45);
    color-scheme:dark;
}
*{box-sizing:border-box;margin:0}
html,body{height:100%}
body{background:var(--bg);color:var(--text);line-height:1.5;font-size:15px;transition:background .2s,color .2s}
a{color:var(--primary-text);text-decoration:none;font-weight:500}a:hover{text-decoration:underline}
h1{font-size:1.4rem}h2{font-size:1.05rem}
.muted{color:var(--muted);font-size:.9rem}.center{text-align:center}
[hidden]{display:none!important}
:focus-visible{outline:2px solid var(--primary);outline-offset:2px}

/* Brand */
.brand{display:flex;align-items:center;gap:.6rem;font-weight:600;font-size:1.05rem}
.brand b{color:var(--primary-text)}
.brand-mark{display:grid;place-items:center;width:34px;height:34px;border-radius:10px;background:var(--primary-soft)}

/* Buttons & inputs */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;padding:.65rem 1.1rem;border:1px solid transparent;border-radius:10px;font:inherit;font-weight:600;cursor:pointer;transition:.15s}
.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover:not(:disabled){background:var(--primary-dark);transform:translateY(-1px)}
.btn-ghost{background:transparent;border-color:var(--border);color:var(--text)}.btn-ghost:hover{background:var(--bg)}
.btn-block{width:100%}.btn:disabled{opacity:.55;cursor:not-allowed}
.icon-btn{background:none;border:0;font-size:1.1rem;cursor:pointer;padding:.4rem .6rem;border-radius:8px;color:var(--text)}.icon-btn:hover{background:var(--bg)}
input[type=text],input[type=email],input[type=password],input[type=search],textarea{
    width:100%;padding:.7rem .85rem;border:1px solid var(--border);border-radius:10px;background:var(--input-bg);font:inherit;color:inherit;transition:.15s}
input:focus,textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-soft)}
input.invalid{border-color:var(--danger)}
label{display:block;font-size:.85rem;font-weight:600;margin:1rem 0 .35rem}
.input-group{position:relative}.input-group input{padding-right:4.2rem}
.toggle-pw{position:absolute;right:.4rem;top:50%;transform:translateY(-50%);background:none;border:0;color:var(--primary-text);font-weight:600;cursor:pointer;padding:.4rem .6rem}
.check{display:flex;align-items:center;gap:.5rem;font-weight:400;margin:0}
.row-between{display:flex;justify-content:space-between;margin:1rem 0}
.spinner{width:16px;height:16px;border:2px solid rgba(255,255,255,.4);border-top-color:#fff;border-radius:50%;animation:spin .7s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.alert{padding:.7rem .9rem;border-radius:10px;font-size:.9rem;margin:1rem 0 0}
.alert.error{background:var(--danger-soft);color:var(--danger)}
.alert.success{background:var(--ok-soft);color:var(--ok)}
.alert.info{background:var(--primary-soft);color:var(--primary-text)}

/* Theme toggle */
.theme-toggle{border:1px solid var(--border);border-radius:10px;background:var(--surface);font-size:1rem;line-height:1}
.theme-toggle.floating{position:fixed;top:1rem;right:1rem;z-index:20}

/* Auth pages */
.auth-body{display:grid;place-items:center;min-height:100%;padding:1rem;
    background:radial-gradient(900px 400px at 80% -10%,var(--glow1),transparent),radial-gradient(700px 400px at 0 100%,var(--glow2),transparent),var(--bg)}
.auth-card{width:100%;max-width:420px;background:var(--surface);padding:2rem;border-radius:18px;box-shadow:var(--shadow);border:1px solid var(--border)}
.auth-card h1{margin:1.5rem 0 .25rem}
.auth-card form{margin-bottom:1.2rem}.auth-card form .btn{margin-top:1.2rem}
.secure{text-align:center;font-size:.8rem;color:var(--muted);margin-top:1rem}

/* App shell */
.app-body{display:flex;flex-direction:column;height:100vh;overflow:hidden}
.topbar{display:flex;align-items:center;gap:1rem;padding:.7rem 1.2rem;background:var(--surface);border-bottom:1px solid var(--border)}
.search{max-width:380px;margin:0 auto}
.user-box{display:flex;align-items:center;gap:.6rem;margin-left:auto}
.topbar .search + .theme-toggle{margin-left:0}
.avatar{display:grid;place-items:center;width:32px;height:32px;border-radius:50%;background:var(--primary);color:#fff;font-weight:600;text-transform:uppercase}
.menu-btn{display:none}
.layout{flex:1;display:flex;min-height:0}
.sidebar{width:290px;flex-shrink:0;background:var(--surface);border-right:1px solid var(--border);padding:1rem;overflow-y:auto}
.side-title{margin:1.4rem 0 .6rem;font-size:.75rem;text-transform:uppercase;letter-spacing:.06em;color:var(--muted)}
.doc-list{list-style:none;padding:0;display:grid;gap:.35rem}
.doc-item{display:flex;align-items:center;gap:.6rem;padding:.6rem .7rem;border-radius:10px;cursor:pointer;border:1px solid transparent;transition:.15s}
.doc-item:hover{background:var(--bg)}
.doc-item.active{background:var(--primary-soft);border-color:var(--active-border)}
.doc-item .name{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:.9rem}
.doc-item small{color:var(--muted)}
.doc-del{flex-shrink:0;background:none;border:0;cursor:pointer;font-size:.9rem;line-height:1;padding:.3rem .4rem;border-radius:6px;opacity:.55;transition:.15s}
.doc-del:hover{opacity:1;background:var(--danger-soft)}
.empty-note{color:var(--muted);font-size:.88rem;padding:.8rem;text-align:center;border:1px dashed var(--border);border-radius:10px}

/* Chat */
.chat{flex:1;display:flex;flex-direction:column;min-width:0}
.chat-header{display:flex;justify-content:space-between;align-items:center;padding:1rem 1.5rem;background:var(--surface);border-bottom:1px solid var(--border)}
.status{display:flex;align-items:center;gap:.4rem;font-size:.85rem;color:var(--muted)}
.dot{width:8px;height:8px;border-radius:50%;background:var(--ok)}
.status.busy .dot{background:#f59e0b;animation:pulse 1s infinite}
@keyframes pulse{50%{opacity:.3}}
.messages{flex:1;overflow-y:auto;padding:1.5rem;display:flex;flex-direction:column;gap:1rem;scroll-behavior:smooth}
.chat-empty{margin:auto;text-align:center;max-width:420px}
.chat-empty .big,.dropzone .big{font-size:2.2rem}
.chips{display:flex;flex-wrap:wrap;gap:.5rem;justify-content:center;margin-top:1rem}
.chip{border:1px solid var(--border);background:var(--surface);color:var(--text);border-radius:999px;padding:.45rem .9rem;font:inherit;font-size:.85rem;cursor:pointer;transition:.15s}
.chip:hover{border-color:var(--primary);color:var(--primary-text)}
.msg{display:flex;flex-direction:column;max-width:min(720px,85%);animation:rise .25s ease}
@keyframes rise{from{opacity:0;transform:translateY(6px)}}
.msg.user{align-self:flex-end;align-items:flex-end}.msg.ai{align-self:flex-start}
.bubble{padding:.8rem 1rem;border-radius:16px;white-space:pre-wrap;word-wrap:break-word;overflow-wrap:anywhere}
.msg.user .bubble{background:var(--primary);color:#fff;border-bottom-right-radius:4px}
.msg.ai .bubble{background:var(--surface);border:1px solid var(--border);border-bottom-left-radius:4px}
.msg.error .bubble{background:var(--danger-soft);border-color:var(--error-border);color:var(--danger)}
.time{font-size:.72rem;color:var(--muted);margin-top:.25rem}
.typing{display:flex;gap:5px;padding:.3rem 0}
.typing i{width:7px;height:7px;border-radius:50%;background:var(--muted);animation:bounce 1.2s infinite}
.typing i:nth-child(2){animation-delay:.15s}.typing i:nth-child(3){animation-delay:.3s}
@keyframes bounce{30%{transform:translateY(-5px);opacity:.5}}
.composer{display:flex;gap:.7rem;align-items:flex-end;padding:1rem 1.5rem;background:var(--surface);border-top:1px solid var(--border)}
.composer textarea{resize:none;max-height:160px}

/* Dialog */
.dialog{border:1px solid var(--border);background:var(--surface);color:var(--text);border-radius:16px;padding:1.4rem;width:min(440px,92vw);box-shadow:var(--shadow);margin:auto}
.dialog::backdrop{background:rgba(10,12,25,.55)}
.dialog-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:1rem}
.dropzone{display:flex;flex-direction:column;align-items:center;gap:.3rem;padding:1.6rem;border:2px dashed var(--border);border-radius:14px;cursor:pointer;text-align:center;margin:0;transition:.15s}
.dropzone:hover{border-color:var(--primary);background:var(--primary-soft)}
.dialog .btn{margin-top:1rem}

@media (max-width:820px){
    .menu-btn{display:block}.search,.user-name{display:none}
    .topbar{gap:.6rem}
    .topbar .brand{flex:1}
    .sidebar{position:fixed;inset:57px auto 0 0;z-index:10;transform:translateX(-100%);transition:.2s;box-shadow:var(--shadow)}
    .sidebar.open{transform:none}
    .msg{max-width:92%}.messages,.composer,.chat-header{padding-left:1rem;padding-right:1rem}
}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}