:root{
  --bg:#090909; --panel:#111111; --panel2:#1a1a1a; --panel3:#222222;
  --border:#262626; --text:#f2f2f2; --muted:#9a9a9a; --faint:#6f6f6f;
  --accent:#ffffff; --user-bubble:#2a2a2a; --ai-bubble:transparent;
  --danger:#3a1d1f; --danger-text:#ffb4b8; --danger-border:#633236;
}
*{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  background:var(--bg);color:var(--text);height:100vh;height:100dvh;overflow:hidden;
}
button{font-family:inherit;cursor:pointer}
.app{display:flex;height:100vh;height:100dvh;width:100%}

/* ---------- sidebar ---------- */
.sidebar{
  width:264px;flex:0 0 auto;background:var(--panel);border-right:1px solid var(--border);
  display:flex;flex-direction:column;padding:14px 10px;gap:6px;min-height:0;z-index:30;
}
.brand{display:flex;align-items:center;gap:9px;font-size:17px;font-weight:700;padding:4px 8px 12px;letter-spacing:.2px}
.brand-mark{
  width:28px;height:28px;border-radius:50%;background:#fff;color:#090909;
  display:flex;align-items:center;justify-content:center;font-size:16px;line-height:1;flex:0 0 auto;overflow:hidden;
}
.brand-mark img{width:100%;height:100%;object-fit:contain;display:block}
.new-chat{
  display:flex;align-items:center;gap:8px;width:100%;padding:10px 12px;border-radius:999px;
  border:1px solid var(--border);background:var(--panel2);color:var(--text);font-size:14px;font-weight:600;text-align:left;
}
.new-chat:hover{background:var(--panel3)}
.history-title{font-size:11px;letter-spacing:.12em;color:var(--faint);font-weight:700;padding:14px 10px 6px}
.history{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:2px;min-height:0}
.history-empty{color:var(--muted);font-size:13px;line-height:1.5;padding:6px 10px}
.chat-item{
  display:flex;align-items:center;gap:6px;padding:9px 10px;border-radius:10px;cursor:pointer;
}
.chat-item:hover{background:var(--panel2)}
.chat-item.active{background:var(--panel3)}
.chat-item .t{flex:1;min-width:0;font-size:13.5px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.chat-item .del{
  background:none;border:none;color:var(--muted);font-size:14px;padding:2px 5px;border-radius:6px;flex:0 0 auto;display:none;
}
.chat-item:hover .del{display:block}
.chat-item .del:hover{color:var(--text);background:#333}
.sidebar-bottom{
  display:flex;align-items:center;gap:8px;color:var(--muted);font-size:13px;
  padding:10px;border-top:1px solid var(--border);
}
.status-dot{width:8px;height:8px;border-radius:50%;background:#3fb950;flex:0 0 auto}

/* ---------- main ---------- */
.main{flex:1;display:flex;flex-direction:column;min-width:0;min-height:0;background:var(--bg)}
.topbar{
  display:flex;align-items:center;gap:12px;padding:12px 16px;flex:0 0 auto;min-height:52px;
}
.menu-btn{display:none;background:none;border:none;color:var(--text);font-size:20px;padding:4px 8px}
.mobile-brand{display:none;font-weight:700;font-size:16px}
.top-label{margin-left:auto;font-size:11px;letter-spacing:.14em;color:var(--faint);font-weight:700}
.conversation{flex:1;overflow-y:auto;padding:10px 16px 20px;min-height:0}
.welcome{max-width:720px;margin:9vh auto 0;text-align:center;padding:0 8px}
.welcome-symbol{
  width:56px;height:56px;margin:0 auto 18px;border-radius:50%;background:#fff;color:#090909;
  display:flex;align-items:center;justify-content:center;font-size:30px;overflow:hidden;
}
.welcome-symbol img{width:100%;height:100%;object-fit:contain;display:block}
.welcome h1{font-size:30px;font-weight:700;margin-bottom:10px}
.welcome p{color:var(--muted);font-size:15.5px;line-height:1.55;margin-bottom:30px}
.suggestions{display:grid;grid-template-columns:1fr 1fr;gap:10px;text-align:left}
.suggestion{
  display:flex;align-items:center;gap:10px;padding:14px 16px;border-radius:16px;
  border:1px solid var(--border);background:var(--panel);color:var(--text);font-size:14.5px;
}
.suggestion:hover{background:var(--panel2)}
.messages{max-width:780px;margin:0 auto;display:flex;flex-direction:column;gap:18px;padding-top:8px}
.msg{display:flex;flex-direction:column;max-width:100%}
.msg .who{font-size:12px;letter-spacing:.08em;color:var(--faint);font-weight:700;margin-bottom:5px;text-transform:uppercase}
.msg.user{align-items:flex-end}
.msg.user .bubble{
  background:var(--user-bubble);border-radius:20px 20px 6px 20px;padding:11px 16px;
  max-width:82%;font-size:15px;line-height:1.55;white-space:pre-wrap;overflow-wrap:anywhere;
}
.msg.assistant .bubble{
  font-size:15px;line-height:1.65;white-space:pre-wrap;overflow-wrap:anywhere;padding:2px 0;max-width:100%;
}
.notice{
  align-self:center;background:var(--danger);color:var(--danger-text);border:1px solid var(--danger-border);
  padding:10px 14px;border-radius:12px;font-size:13.5px;text-align:center;max-width:92%;line-height:1.5;
}
.typing{display:flex;gap:5px;padding:6px 0}
.typing span{width:7px;height:7px;border-radius:50%;background:var(--muted);animation:blink 1.2s infinite}
.typing span:nth-child(2){animation-delay:.2s}.typing span:nth-child(3){animation-delay:.4s}
@keyframes blink{0%,80%,100%{opacity:.25}40%{opacity:1}}

/* ---------- composer ---------- */
.composer{flex:0 0 auto;padding:10px 16px calc(10px + env(safe-area-inset-bottom));background:var(--bg)}
.input-wrap{
  max-width:780px;margin:0 auto;display:flex;align-items:flex-end;gap:8px;
  background:var(--panel2);border:1px solid var(--border);border-radius:26px;padding:8px 8px 8px 18px;
}
.input-wrap textarea{
  flex:1;background:none;border:none;outline:none;resize:none;color:var(--text);
  font-size:15.5px;line-height:1.45;max-height:160px;padding:7px 0;font-family:inherit;min-width:0;
}
.input-wrap textarea::placeholder{color:var(--faint)}
.send-btn{
  flex:0 0 auto;width:36px;height:36px;border:none;border-radius:50%;
  background:#fff;color:#090909;font-size:18px;font-weight:700;line-height:1;
  display:flex;align-items:center;justify-content:center;
}
.send-btn:disabled{opacity:.35;cursor:default}
.disclaimer{text-align:center;color:var(--faint);font-size:12px;margin-top:9px}

/* ---------- mobile ---------- */
@media (max-width:760px){
  .sidebar{
    position:fixed;top:0;left:0;bottom:0;transform:translateX(-105%);transition:transform .22s ease;
    box-shadow:0 0 40px rgba(0,0,0,.6);
  }
  .sidebar.open{transform:translateX(0)}
  .menu-btn{display:block}
  .mobile-brand{display:block}
  .top-label{display:none}
  .suggestions{grid-template-columns:1fr}
  .welcome{margin-top:5vh}
  .welcome h1{font-size:26px}
  .msg.user .bubble{max-width:92%}
}