:root{
  --bg:#0d0f14; --panel:#171a21; --panel-2:#1e222b; --hover:#232833;
  --ink:#ececf1; --muted:#98a0b0; --faint:#6b7280;
  --line:rgba(255,255,255,.08);
  --cyan:#33e1ed; --violet:#8b7bff;
  --accent:linear-gradient(120deg,var(--cyan),var(--violet));
  --user:#2a2f3a;
  --radius:14px;
}
*{box-sizing:border-box}
html,body{height:100%;margin:0}
body{
  background:var(--bg); color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  -webkit-font-smoothing:antialiased;
}
button{font-family:inherit}
.dot{width:9px;height:9px;border-radius:50%;background:var(--cyan);
  box-shadow:0 0 10px var(--cyan);display:inline-block;animation:pulse 2.6s ease-in-out infinite}
@keyframes pulse{0%,100%{transform:scale(1);opacity:1}50%{transform:scale(1.45);opacity:.55}}

#app{display:flex;height:100dvh;overflow:hidden}

/* ---------- Sidebar ---------- */
#sidebar{
  width:260px;flex:0 0 260px;background:#0a0c11;border-right:1px solid var(--line);
  display:flex;flex-direction:column;transition:transform .22s ease;z-index:40;
}
.side-top{padding:12px}
.new-chat{
  width:100%;display:flex;align-items:center;gap:9px;justify-content:flex-start;
  background:var(--panel);color:var(--ink);border:1px solid var(--line);border-radius:12px;
  padding:11px 13px;font-size:14px;font-weight:600;cursor:pointer;transition:background .15s}
.new-chat:hover{background:var(--hover)}
.history{flex:1;overflow-y:auto;padding:4px 8px;display:flex;flex-direction:column;gap:2px}
.hist-item{
  display:flex;align-items:center;gap:8px;padding:9px 10px;border-radius:9px;cursor:pointer;
  color:var(--muted);font-size:13.5px;white-space:nowrap;overflow:hidden}
.hist-item:hover{background:var(--hover);color:var(--ink)}
.hist-item.active{background:var(--panel-2);color:var(--ink)}
.hist-item .t{flex:1;overflow:hidden;text-overflow:ellipsis}
.hist-item .del{opacity:0;color:var(--faint);border:0;background:none;cursor:pointer;padding:2px;border-radius:6px}
.hist-item:hover .del{opacity:1}
.hist-item .del:hover{color:#ff7a7a}
.side-foot{padding:14px;border-top:1px solid var(--line);font-size:12.5px;color:var(--muted)}
.memnote{display:flex;gap:8px;align-items:flex-start;line-height:1.5;margin-bottom:10px}
.side-link{color:var(--cyan);text-decoration:none;display:block;margin-bottom:8px}
.side-link:hover{text-decoration:underline}
.madeby{color:var(--faint)}

#scrim{display:none;position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:30}

/* ---------- Main ---------- */
#main{flex:1;display:flex;flex-direction:column;min-width:0}
.topbar{
  display:flex;align-items:center;gap:10px;padding:10px 14px;border-bottom:1px solid var(--line);
  background:rgba(13,15,20,.8);backdrop-filter:blur(8px)}
.wordmark{display:flex;align-items:center;gap:9px;font-weight:700;letter-spacing:.01em;flex:1}
.icon-btn{background:none;border:0;color:var(--muted);cursor:pointer;padding:6px;border-radius:8px;display:flex}
.icon-btn:hover{background:var(--hover);color:var(--ink)}
#menuBtn{display:none}

.scroll{flex:1;overflow-y:auto;scroll-behavior:smooth}
.thread{max-width:46rem;margin:0 auto;padding:26px 20px 12px;display:flex;flex-direction:column;gap:22px}

.msg{display:flex;gap:14px;align-items:flex-start;animation:fade .25s ease both}
@keyframes fade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
.avatar{flex:0 0 30px;width:30px;height:30px;border-radius:50%;display:grid;place-items:center;
  font-size:13px;font-weight:700;color:#04121a;background:var(--accent);
  box-shadow:0 0 0 1px var(--line)}
.msg.user .avatar{background:var(--user);color:var(--ink);box-shadow:none}
.bubble{padding-top:3px;line-height:1.65;font-size:15.5px;word-wrap:break-word;overflow-wrap:anywhere;min-width:0}
.msg.user .bubble{color:#e7e9f0}
.bubble code{background:#0b0d12;border:1px solid var(--line);border-radius:6px;padding:1px 6px;font-size:13.5px}
.bubble strong{color:#fff}
.role{font-size:12px;color:var(--faint);margin-bottom:2px;font-weight:600;letter-spacing:.02em}

.typing{display:inline-flex;gap:5px;padding:6px 2px}
.typing i{width:7px;height:7px;border-radius:50%;background:var(--muted);animation:blink 1.3s infinite}
.typing i:nth-child(2){animation-delay:.2s}.typing i:nth-child(3){animation-delay:.4s}
@keyframes blink{0%,60%,100%{opacity:.25;transform:translateY(0)}30%{opacity:1;transform:translateY(-3px)}}

/* Empty state */
.empty{max-width:46rem;margin:0 auto;padding:9vh 20px 20px;text-align:center;display:flex;
  flex-direction:column;align-items:center}
.empty.hide{display:none}
.mark{width:56px;height:56px;border-radius:50%;background:var(--accent);display:grid;place-items:center;margin-bottom:20px;
  box-shadow:0 12px 40px -12px var(--violet)}
.mark .pulse{width:14px;height:14px;border-radius:50%;background:#0a0c11;position:relative}
.mark .pulse::after{content:"";position:absolute;inset:-6px;border-radius:50%;border:2px solid rgba(255,255,255,.5);animation:ring 2.4s ease-out infinite}
@keyframes ring{0%{transform:scale(.6);opacity:.8}100%{transform:scale(1.5);opacity:0}}
.empty h1{font-size:29px;margin:0 0 8px;font-weight:700}
.empty .sub{color:var(--muted);max-width:34rem;line-height:1.6;margin:0 0 26px}
.chips{display:flex;flex-wrap:wrap;gap:10px;justify-content:center}
.chip{background:var(--panel);border:1px solid var(--line);color:var(--ink);border-radius:12px;
  padding:11px 15px;font-size:14px;cursor:pointer;transition:background .15s,border-color .15s}
.chip:hover{background:var(--hover);border-color:rgba(51,225,237,.4)}

/* Composer */
.composer{padding:8px 16px 16px;background:linear-gradient(to top,var(--bg) 60%,transparent)}
.composer-inner{max-width:46rem;margin:0 auto;display:flex;align-items:flex-end;gap:8px;
  background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:8px 8px 8px 16px;
  transition:border-color .15s}
.composer-inner:focus-within{border-color:rgba(139,123,255,.55)}
#input{flex:1;background:none;border:0;outline:0;color:var(--ink);font-size:15.5px;resize:none;
  max-height:200px;line-height:1.5;padding:8px 0}
#input::placeholder{color:var(--faint)}
.send{flex:0 0 36px;width:36px;height:36px;border-radius:11px;border:0;cursor:pointer;color:#04121a;
  background:var(--accent);display:grid;place-items:center;transition:opacity .15s,transform .1s}
.send:disabled{opacity:.35;cursor:default;background:var(--hover);color:var(--muted)}
.send:not(:disabled):hover{transform:translateY(-1px)}
.disclaimer{max-width:46rem;margin:8px auto 0;text-align:center;font-size:12px;color:var(--faint)}

/* Mobile */
@media (max-width:820px){
  #sidebar{position:fixed;inset:0 auto 0 0;transform:translateX(-100%)}
  #app.side-open #sidebar{transform:translateX(0)}
  #app.side-open #scrim{display:block}
  #menuBtn{display:flex}
}
@media (prefers-reduced-motion:reduce){*{animation:none!important}}