v2.css

:root{
  --bg:#fff;--side:#fafafa;--rail:#f4f4f5;--line:#ececee;--line2:#dedee2;--ink:#18181b;--ink2:#3f3f46;--mute:#71717a;--faint:#a1a1aa;
  --hover:#f0f0f2;--sel:#e9e9ec;--ubub:#f1f1f3;--abub:#fff;--focus:#18181b;--warn:#b45309;--live:#16a34a;
  font:14px/1.55 -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;color:var(--ink);
  -webkit-font-smoothing:antialiased;
}
@media (prefers-color-scheme:dark){:root{
  --bg:#0f0f10;--side:#141416;--rail:#18181b;--line:#232326;--line2:#2e2e33;--ink:#ededef;--ink2:#c8c8cc;--mute:#8b8b93;--faint:#5c5c63;
  --hover:#1c1c1f;--sel:#232327;--ubub:#1f1f23;--abub:#141416;--focus:#ededef;--warn:#f59e0b;--live:#22c55e}}
*{box-sizing:border-box}
body{margin:0;height:100vh;display:grid;grid-template-columns:64px 264px 1fr;background:var(--bg);overflow:hidden}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer;padding:0}
kbd{font:11px/1 ui-monospace,SFMono-Regular,Menlo,monospace;color:var(--faint);border:1px solid var(--line2);border-radius:4px;padding:2px 4px}
:focus-visible{outline:1.5px solid var(--focus);outline-offset:1px}

/* rail */
#rail{background:var(--rail);border-right:1px solid var(--line);display:flex;flex-direction:column;justify-content:space-between;padding:12px 0}
.chs{display:flex;flex-direction:column;align-items:center;gap:4px}
.ch{width:56px;display:flex;flex-direction:column;align-items:center;gap:3px;padding:5px 0;border-radius:8px;color:var(--mute)}
.tile{position:relative;width:32px;height:32px;border-radius:8px;display:grid;place-items:center;font-weight:600;font-size:13.5px;border:1px solid var(--line2);background:var(--bg);color:var(--ink2);transition:background .12s,border-color .12s}
.ch:hover .tile{border-color:var(--faint)}
.ch.on .tile{background:var(--ink);border-color:var(--ink);color:var(--bg)}
.lbl{font-size:10.5px;line-height:1.2;max-width:54px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.ch.on .lbl{color:var(--ink);font-weight:500}
.pip{position:absolute;top:-2px;right:-2px;width:8px;height:8px;border-radius:50%;background:var(--warn);border:2px solid var(--rail)}
.ch.add .tile{border-style:dashed;background:none;color:var(--faint)}
.foot{display:flex;flex-direction:column;align-items:center;gap:10px}
.iconbtn{width:32px;height:32px;border-radius:8px;display:grid;place-items:center;color:var(--mute)}.iconbtn:hover{background:var(--hover);color:var(--ink)}
.me{width:28px;height:28px;border-radius:50%;background:var(--line2);display:grid;place-items:center;font-size:12px;font-weight:600;color:var(--ink2)}

/* sessions column */
#side{background:var(--side);border-right:1px solid var(--line);display:flex;flex-direction:column;min-height:0;padding:16px 10px 10px}
.chhead{padding:2px 8px 14px}.chhead h2{margin:0;font-size:15px;font-weight:600;letter-spacing:-.01em}
.chhead p{margin:3px 0 0;color:var(--mute);font-size:12.5px;line-height:1.45}
.new,.search{display:flex;align-items:center;gap:8px;height:32px;padding:0 8px;border-radius:7px;color:var(--ink2)}
.new:hover{background:var(--hover)}.new span{flex:1;text-align:left}
.search{color:var(--mute);margin-top:2px}.search:focus-within{background:var(--bg);box-shadow:0 0 0 1px var(--line2)}
.search input{flex:1;min-width:0;border:0;outline:0;background:none;font:inherit;color:var(--ink)}.search input::placeholder{color:var(--mute)}
.search:focus-within kbd{display:none}
.sessions{flex:1;overflow:auto;margin:10px -2px 0;padding:0 2px}
.grp{font-size:11.5px;font-weight:500;color:var(--faint);padding:12px 8px 4px}
.sess{display:flex;align-items:center;gap:8px;height:32px;padding:0 8px;border-radius:7px;color:var(--ink2);text-decoration:none}
.sess:hover{background:var(--hover)}.sess.on{background:var(--sel);color:var(--ink)}
.sess .t{flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.when{font-size:12px;color:var(--faint);font-variant-numeric:tabular-nums}
.tag{font-size:11px;color:var(--warn);font-weight:500}
.empty{color:var(--mute);font-size:13px;padding:12px 8px}
.drawer{border-top:1px solid var(--line);padding-top:6px;margin-top:6px}
.drow{width:100%;display:flex;align-items:center;gap:8px;height:30px;padding:0 8px;border-radius:7px;color:var(--mute);font-size:13px}
.drow:hover{background:var(--hover);color:var(--ink2)}.drow span{flex:1;text-align:left}.drow b{font-weight:500;font-variant-numeric:tabular-nums}
.drow svg:last-child{transition:transform .12s}.drow.open svg:last-child{transform:rotate(90deg)}
.dlist{padding:2px 8px 8px 31px;font-size:12.5px;color:var(--mute);line-height:1.45}.dlist div{padding:3px 0}

/* stage */
#stage{display:flex;flex-direction:column;min-width:0;min-height:0}
header{height:52px;flex:none;display:flex;align-items:center;gap:12px;padding:0 24px;border-bottom:1px solid var(--line)}
header h1{margin:0;font-size:14.5px;font-weight:600;flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.meta{display:flex;align-items:center;gap:6px;font-size:12.5px;color:var(--mute)}
.st{width:6px;height:6px;border-radius:50%;background:var(--faint)}.st.open{background:var(--live)}.st.waiting{background:var(--warn)}
.scroll{flex:1;overflow:auto}
.msgs{max-width:720px;margin:0 auto;padding:28px 24px 32px;display:flex;flex-direction:column;gap:4px}
.m{display:flex;flex-direction:column}.m.first{margin-top:16px}.m.first:first-child{margin-top:0}
.m.user{align-items:flex-end}.m.agent{align-items:flex-start}
.who{font-size:12.5px;font-weight:600;margin:0 0 5px 2px;display:flex;gap:8px;align-items:baseline}.who span{font-weight:400;color:var(--faint);font-size:12px}
.bubble{max-width:82%;padding:9px 13px;border-radius:14px;overflow-wrap:anywhere}
.user .bubble{background:var(--ubub);white-space:pre-wrap;border-bottom-right-radius:5px}
.agent .bubble{background:var(--abub);border:1px solid var(--line);border-bottom-left-radius:5px}
.body>*:first-child{margin-top:0}.body>*:last-child{margin-bottom:0}.body p{margin:.5em 0}.body ul,.body ol{padding-left:1.2em;margin:.5em 0}
.body small{color:var(--faint);font-size:11.5px}
.body strong{font-weight:600}
.body table{border-collapse:collapse;font-size:13px;margin:.5em 0;font-variant-numeric:tabular-nums}.body th{font-weight:500;color:var(--mute);text-align:left}
.body td,.body th{border-bottom:1px solid var(--line);padding:5px 14px 5px 0}.body tr:last-child td{border-bottom:0}
.body code{font:12.5px ui-monospace,SFMono-Regular,Menlo,monospace;background:var(--hover);padding:1px 4px;border-radius:4px}
.steps{margin:-1px 0 8px;font-size:12.5px;color:var(--mute)}
.steps summary{list-style:none;display:inline-flex;align-items:center;gap:6px;cursor:pointer;border-radius:5px;padding:1px 0}.steps summary::-webkit-details-marker{display:none}
.steps summary:hover{color:var(--ink2)}.steps summary svg:last-child{transition:transform .12s}.steps[open] summary svg:last-child{transform:rotate(90deg)}
.steps code{display:block;margin-top:6px;font:12px/1.5 ui-monospace,SFMono-Regular,Menlo,monospace;color:var(--ink2);background:var(--side);border:1px solid var(--line);border-radius:6px;padding:6px 8px;white-space:pre-wrap}
.typing{display:inline-flex;gap:4px;padding:4px 0}.typing i{width:5px;height:5px;border-radius:50%;background:var(--faint);animation:b 1.1s infinite}.typing i:nth-child(2){animation-delay:.15s}.typing i:nth-child(3){animation-delay:.3s}@keyframes b{50%{opacity:.3}}

/* composer */
.composer{max-width:720px;width:calc(100% - 48px);margin:0 auto 20px;border:1px solid var(--line2);border-radius:12px;background:var(--bg);padding:10px 10px 8px 14px;transition:border-color .12s}
.composer:focus-within{border-color:var(--faint)}
.composer textarea{width:100%;border:0;outline:0;resize:none;background:none;font:inherit;color:var(--ink);line-height:1.5;max-height:220px}
.composer textarea::placeholder{color:var(--faint)}
.cbar{display:flex;align-items:center;justify-content:space-between;margin-top:4px}
.hint{font-size:11.5px;color:var(--faint)}
#go{width:28px;height:28px;border-radius:7px;display:grid;place-items:center;background:var(--ink);color:var(--bg)}
#go:disabled{background:var(--line2);color:var(--faint);cursor:default}
.blank{flex:1;display:flex;flex-direction:column;justify-content:center;padding-bottom:12vh}
.blank h1{margin:0 auto;font-size:22px;font-weight:600;letter-spacing:-.02em;max-width:720px;width:calc(100% - 48px)}
.blank p{margin:4px auto 20px;color:var(--mute);max-width:720px;width:calc(100% - 48px)}
.blank .composer{margin-bottom:0}