:root{
  --bg:#0f1115; --panel:#171a21; --panel2:#1e222b; --line:#2a2f3a;
  --tx:#e8ebf0; --tx2:#9aa3b2;
  --gpt:#10a37f; --gem:#4a8bf5; --clo:#d97757;
  --safe-b: env(safe-area-inset-bottom, 0px);
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0; background:var(--bg); color:var(--tx);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Malgun Gothic","Apple SD Gothic Neo",sans-serif;
  display:flex; flex-direction:column; overflow:hidden;
}

/* top */
.topbar{display:flex;align-items:center;justify-content:space-between;padding:10px 14px;
  padding-top:calc(10px + env(safe-area-inset-top,0px));border-bottom:1px solid var(--line);background:var(--panel)}
.brand{display:flex;align-items:center;gap:6px;font-size:15px}
.brand strong{margin-left:4px;letter-spacing:-.3px}
.dot{width:9px;height:9px;border-radius:50%;display:inline-block}
.dot.gpt{background:var(--gpt)} .dot.gem{background:var(--gem)} .dot.clo{background:var(--clo)}
.top-actions{display:flex;gap:4px}
button{font:inherit;cursor:pointer}
.ghost{background:transparent;border:0;color:var(--tx2);font-size:18px;padding:6px 8px;border-radius:8px}
.ghost:hover{background:var(--panel2);color:var(--tx)}

/* modes */
.modes{display:flex;gap:6px;padding:8px 10px;overflow-x:auto;border-bottom:1px solid var(--line);background:var(--panel)}
.mode{flex:0 0 auto;background:var(--panel2);border:1px solid var(--line);color:var(--tx2);
  padding:6px 12px;border-radius:999px;font-size:13px}
.mode.active{background:#fff;color:#111;border-color:#fff;font-weight:600}

/* who */
.who{display:flex;align-items:center;gap:12px;padding:8px 12px;border-bottom:1px solid var(--line);
  background:var(--panel);font-size:13px;overflow-x:auto}
.who label{display:flex;align-items:center;gap:5px;white-space:nowrap;cursor:pointer}
.who input{accent-color:#fff;width:16px;height:16px}
.tag{font-weight:600}
.tag.gpt{color:var(--gpt)} .tag.gem{color:var(--gem)} .tag.clo{color:var(--clo)}
.mini{margin-left:auto;background:var(--panel2);color:var(--tx2);border:1px solid var(--line);
  border-radius:8px;padding:5px 8px;font-size:12px}

/* chat */
.chat{flex:1;overflow-y:auto;padding:14px 12px 6px;-webkit-overflow-scrolling:touch}
.empty{max-width:520px;margin:8vh auto;text-align:center;color:var(--tx2);line-height:1.8}
.empty h2{color:var(--tx);font-size:20px;margin-bottom:14px}
.hint{margin-top:18px;font-size:13px;color:#6f7a8b}

.turn{max-width:900px;margin:0 auto 18px}
.q{background:var(--panel2);border:1px solid var(--line);border-radius:14px;padding:11px 14px;
  margin-bottom:12px;white-space:pre-wrap;word-break:break-word;line-height:1.6}

.cards{display:grid;gap:10px;grid-template-columns:1fr}
@media(min-width:820px){ .cards.multi{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))} }

.card{background:var(--panel);border:1px solid var(--line);border-radius:14px;overflow:hidden}
.card.gpt{border-top:3px solid var(--gpt)}
.card.gem{border-top:3px solid var(--gem)}
.card.clo{border-top:3px solid var(--clo)}
.card.final{border:1px solid #4d566b;background:#161a22}
.card-h{display:flex;align-items:center;gap:8px;padding:8px 12px;border-bottom:1px solid var(--line);
  font-size:12.5px;font-weight:600;color:var(--tx2)}
.card-h .step{background:var(--panel2);border-radius:6px;padding:1px 6px;font-size:11px;font-weight:500}
.card-h .copy{margin-left:auto;background:transparent;border:0;color:#5f6a7a;font-size:14px;padding:2px 4px}
.card-h .copy:hover{color:var(--tx)}
.body{padding:12px 14px;line-height:1.72;font-size:14.5px;word-break:break-word}
.body p{margin:0 0 10px} .body p:last-child{margin-bottom:0}
.body a{color:#6ea8fe}
.body code{background:#0b0d11;padding:1px 5px;border-radius:5px;font-size:13px}
.body pre{background:#0b0d11;padding:10px 12px;border-radius:10px;overflow-x:auto;white-space:pre}
.body pre code{background:none;padding:0}
.body h3{font-size:15px;margin:14px 0 6px}
.body table{border-collapse:collapse;width:100%;font-size:13px;margin:8px 0;display:block;overflow-x:auto}
.body th,.body td{border:1px solid var(--line);padding:5px 8px;text-align:left}
.body ul,.body ol{padding-left:20px;margin:6px 0}
.err{color:#ff7b72;font-size:13.5px;white-space:pre-wrap}
.loading{display:inline-block;color:var(--tx2);font-size:13px}
.loading::after{content:'';animation:dots 1.2s steps(4,end) infinite}
@keyframes dots{0%{content:''}25%{content:'·'}50%{content:'··'}75%{content:'···'}}

/* composer */
.composer{display:flex;gap:8px;padding:10px 12px;padding-bottom:calc(10px + var(--safe-b));
  border-top:1px solid var(--line);background:var(--panel)}
#input{flex:1;resize:none;max-height:150px;background:var(--panel2);border:1px solid var(--line);
  color:var(--tx);border-radius:12px;padding:11px 13px;font:inherit;font-size:15px;line-height:1.5;outline:none}
#input:focus{border-color:#4a5568}
#send{width:46px;border:0;border-radius:12px;background:#fff;color:#111;font-size:17px}
#send:disabled{opacity:.4}

/* modal */
.modal{position:fixed;inset:0;background:rgba(0,0,0,.6);display:flex;align-items:flex-end;justify-content:center;z-index:50}
@media(min-width:640px){ .modal{align-items:center} }
.sheet{background:var(--panel);width:100%;max-width:520px;max-height:92vh;overflow-y:auto;
  border-radius:18px 18px 0 0;padding:16px 16px calc(16px + var(--safe-b));border:1px solid var(--line)}
@media(min-width:640px){ .sheet{border-radius:18px} }
.sheet-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:14px}
.sheet-head h3{margin:0;font-size:17px}
.seg{display:flex;gap:6px;background:var(--panel2);padding:4px;border-radius:12px;margin-bottom:8px}
.segbtn{flex:1;background:transparent;border:0;color:var(--tx2);padding:9px;border-radius:9px;font-size:13.5px}
.segbtn.active{background:#fff;color:#111;font-weight:600}
.note{font-size:12.5px;color:var(--tx2);line-height:1.6;margin:0 0 14px}
.fld{display:block;margin-bottom:12px}
.fld>span{display:block;font-size:12.5px;color:var(--tx2);margin-bottom:5px}
.fld a{color:#6ea8fe;text-decoration:none;margin-left:4px}
.fld input,.sheet textarea{width:100%;background:var(--panel2);border:1px solid var(--line);color:var(--tx);
  border-radius:10px;padding:10px 12px;font:inherit;font-size:14px;outline:none}
.chk{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--tx2);margin:4px 0 10px}
.adv{border-top:1px solid var(--line);padding:12px 0 4px}
.adv summary{font-size:13.5px;color:var(--tx2);cursor:pointer;margin-bottom:10px}
.sheet-foot{display:flex;gap:8px;margin-top:14px}
.sheet-foot button{flex:1;padding:12px;border-radius:11px;border:1px solid var(--line);
  background:var(--panel2);color:var(--tx);font-size:14.5px}
.primary{background:#fff !important;color:#111 !important;border-color:#fff !important;font-weight:600}
.testout{margin-top:12px;font-size:13px;line-height:1.8;white-space:pre-wrap;color:var(--tx2)}
code{font-family:ui-monospace,Consolas,monospace;font-size:12.5px}