*{box-sizing:border-box}
:root{
  --navy:#102a43;
  --blue:#1677b7;
  --blue2:#0d5f96;
  --red:#c83b45;
  --ink:#1e2936;
  --muted:#6c7885;
  --line:#e4e9ee;
  --panel:#f7f9fb;
  --white:#fff;
  --shadow:0 12px 35px rgba(16,42,67,.10);
}
html,body{height:100%;margin:0;font-family:Inter,Segoe UI,Arial,sans-serif;color:var(--ink);background:#f4f7fa}
button,textarea{font:inherit}
.app-shell{height:100vh;display:flex;overflow:hidden;background:var(--white)}
.sidebar{width:286px;flex:0 0 286px;border-right:1px solid var(--line);background:#fbfcfd;display:flex;flex-direction:column;padding:22px 16px}
.brand{display:flex;align-items:center;gap:11px;padding:3px 9px 24px}
.brand-mark{width:38px;height:38px;border-radius:10px;background:linear-gradient(145deg,var(--blue),var(--navy));color:#fff;display:grid;place-items:center;font-weight:800;font-size:20px;box-shadow:0 5px 14px rgba(22,119,183,.22)}
.brand-name{font-weight:800;letter-spacing:1.5px;color:var(--navy);font-size:15px}
.brand-sub{font-size:9px;letter-spacing:1.8px;color:var(--red);font-weight:700;margin-top:2px}
.new-chat{border:0;background:var(--navy);color:#fff;border-radius:10px;padding:12px 14px;text-align:left;font-weight:700;cursor:pointer;margin-bottom:23px}
.new-chat:hover{background:#0b2033}
.side-section{margin-bottom:22px}
.side-label{text-transform:uppercase;letter-spacing:1.1px;font-size:10px;font-weight:800;color:#8a95a0;padding:0 9px 8px}
.quick-link,.history-item{width:100%;border:0;background:transparent;text-align:left;border-radius:8px;padding:9px 10px;color:#334354;font-size:13px;cursor:pointer}
.quick-link:hover,.history-item:hover{background:#edf4f8}
.history-item{cursor:default;color:#697582}
.sidebar-footer{margin-top:auto;border-top:1px solid var(--line);padding:14px 9px 3px;display:flex;align-items:center;gap:8px;color:#7b8792;font-size:11px}
.secure-dot{width:7px;height:7px;border-radius:50%;background:#2aa56b}
.main{min-width:0;flex:1;display:flex;flex-direction:column;background:#fff}
.topbar{height:72px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 28px;background:rgba(255,255,255,.97)}
.assistant-title{display:flex;align-items:center;gap:11px}
.lucy-avatar{width:36px;height:36px;border-radius:50%;background:linear-gradient(145deg,#e9f5fb,#d8ebf7);color:var(--blue2);display:grid;place-items:center;font-weight:800;border:1px solid #cfe4ef}
.assistant-title strong{display:block;font-size:15px;color:var(--navy)}
.assistant-title span{display:block;font-size:11px;color:var(--muted);margin-top:2px}
.status{font-size:11px;color:#6c7885;display:flex;align-items:center;gap:7px}
.status span{width:7px;height:7px;background:#2aa56b;border-radius:50%}
.mobile-menu{display:none;border:0;background:none;font-size:21px;color:var(--navy);margin-right:7px}
.chat{flex:1;overflow:auto;padding:42px 24px 24px}
.welcome{max-width:850px;margin:0 auto;text-align:center;padding:20px 0 40px}
.large-avatar{width:62px;height:62px;margin:0 auto 18px;border-radius:18px;background:linear-gradient(145deg,var(--blue),var(--navy));color:#fff;display:grid;place-items:center;font-size:27px;font-weight:800;box-shadow:var(--shadow)}
.welcome h1{font-size:30px;color:var(--navy);margin:0 0 10px}
.welcome>p{max-width:650px;margin:0 auto;color:#687685;line-height:1.6;font-size:14px}
.notice{max-width:650px;margin:22px auto 27px;background:#f5f9fc;border:1px solid #dceaf2;border-radius:11px;padding:12px 15px;text-align:left;display:flex;gap:10px;line-height:1.45;font-size:11px}
.notice strong{color:var(--blue2);white-space:nowrap}
.notice span{color:#647482}
.suggestions{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;text-align:left}
.suggestions button{border:1px solid var(--line);background:#fff;border-radius:12px;padding:15px;cursor:pointer;box-shadow:0 2px 7px rgba(20,40,60,.03)}
.suggestions button:hover{border-color:#b9d7e7;box-shadow:0 6px 18px rgba(20,60,90,.07)}
.suggestions b{display:block;color:var(--navy);font-size:13px;margin-bottom:4px}
.suggestions small{color:#788692;font-size:11px;line-height:1.4}
.message{max-width:850px;margin:0 auto 18px;display:flex;gap:10px;align-items:flex-start}
.message.user{justify-content:flex-end}
.message .bubble{max-width:75%;border-radius:14px;padding:12px 14px;line-height:1.55;font-size:14px;white-space:pre-wrap}
.message.assistant .bubble{background:#f3f7fa;border:1px solid #e2e9ee}
.message.user .bubble{background:var(--navy);color:#fff}
.composer-wrap{padding:10px 24px 18px;background:#fff}
.composer{max-width:850px;margin:0 auto;border:1px solid #cfd9e1;border-radius:15px;min-height:54px;display:flex;align-items:flex-end;padding:7px 8px 7px 12px;box-shadow:0 5px 20px rgba(20,50,80,.06)}
.composer:focus-within{border-color:#8bbbd5;box-shadow:0 5px 22px rgba(22,119,183,.10)}
.composer textarea{flex:1;border:0;outline:0;resize:none;max-height:150px;padding:8px 9px;font-size:14px;line-height:1.4;color:var(--ink);background:transparent}
.attach,.send{border:0;width:38px;height:38px;border-radius:10px;cursor:pointer;display:grid;place-items:center}
.attach{background:transparent;color:#71808d;font-size:22px}
.send{background:var(--navy);color:#fff;font-size:16px}
.send:hover{background:var(--blue2)}
.composer-note{text-align:center;color:#8b96a0;font-size:10px;margin-top:7px}
.toast{position:fixed;bottom:85px;left:50%;transform:translateX(-50%) translateY(10px);background:#1d2e3d;color:#fff;padding:9px 13px;border-radius:8px;font-size:11px;opacity:0;pointer-events:none;transition:.2s}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}
@media(max-width:800px){
  .sidebar{position:fixed;z-index:10;left:-300px;top:0;bottom:0;transition:.2s;box-shadow:var(--shadow)}
  .sidebar.open{left:0}
  .mobile-menu{display:block}
  .topbar{padding:0 14px}
  .chat{padding:25px 14px}
  .suggestions{grid-template-columns:1fr}
  .welcome h1{font-size:25px}
  .composer-wrap{padding:8px 12px 13px}
}