:root{
  --bg:#ffffff;--panel:#f6f7fb;--panel2:#eceff7;--line:#dde1ee;--text:#151826;--muted:#566080;
  --a:#6d4aff;--b:#2563eb;--link:#1d4ed8;--danger:#e11d48;--ok:#059669;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.65 system-ui,-apple-system,Segoe UI,Roboto,sans-serif}
a{color:var(--link)}
.wrap{max-width:1040px;margin:0 auto;padding:0 18px}
header.top{display:flex;align-items:center;justify-content:space-between;padding:14px 0;border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:center;gap:0;text-decoration:none;color:var(--text);font-weight:800;font-size:1.25rem}
.brand img{width:34px;height:34px;margin-right:10px}
.brand span{color:var(--a)}
nav a{color:var(--muted);text-decoration:none;margin-left:16px;font-size:.95rem}
nav a:hover{color:var(--text)}
.hero{text-align:center;padding:40px 0 14px}
.hero h1{font-size:clamp(1.8rem,4.6vw,3rem);line-height:1.15;margin:0 0 12px;letter-spacing:-.02em}
.grad{background:linear-gradient(90deg,#6d4aff,#2563eb);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p.sub{color:var(--muted);max-width:680px;margin:0 auto 24px;font-size:1.06rem}
.card{background:#fff;border:1px solid var(--line);border-radius:18px;padding:22px;max-width:640px;margin:0 auto;text-align:left;box-shadow:0 10px 40px rgba(40,50,100,.09)}
.modes{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:16px}
.mode-btn{background:var(--panel);border:2px solid var(--line);color:var(--text);border-radius:14px;padding:16px 10px;cursor:pointer;font-size:1rem;font-weight:700;text-align:center}
.mode-btn small{display:block;color:var(--muted);font-weight:400;margin-top:2px}
.mode-btn.on{border-color:var(--a);background:#6d4aff12}
label.f{display:block;font-size:.85rem;color:var(--muted);margin:12px 0 6px}
select,input[type=text]{width:100%;background:#fff;border:1px solid var(--line);color:var(--text);border-radius:10px;padding:11px 12px;font-size:1rem}
select:focus,input[type=text]:focus{outline:2px solid #6d4aff55;border-color:var(--a)}
.chips{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}
.chip{background:#6d4aff12;border:1px solid var(--a);color:#4b2fd1;border-radius:999px;padding:2px 10px;font-size:.85rem;cursor:pointer}
.age{display:flex;gap:10px;align-items:flex-start;margin:16px 0;font-size:.9rem;color:var(--muted)}
.age input{margin-top:5px}
.btn{background:linear-gradient(90deg,#6d4aff,#2563eb);border:0;color:#fff;font-weight:800;font-size:1.1rem;border-radius:12px;padding:14px 18px;cursor:pointer;width:100%}
.btn:hover{filter:brightness(1.07)}
.btn.sec{background:#fff;border:1px solid var(--line);color:var(--text);font-size:.95rem;font-weight:600;width:auto;padding:10px 14px}
.btn.sec:hover{background:var(--panel)}
.btn.danger{background:var(--danger)}
.live{color:var(--ok);font-size:.9rem;margin-top:12px;text-align:center}
.live i{display:inline-block;width:8px;height:8px;border-radius:50%;background:var(--ok);margin-right:6px}
.note{font-size:.8rem;color:var(--muted);text-align:center;margin-top:10px}
section.block{padding:34px 0}
section.block h2{font-size:1.55rem;margin:0 0 10px;letter-spacing:-.01em}
section.block p{color:var(--muted);max-width:820px}
section.block li{color:var(--muted);margin:4px 0}
.grid3{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:14px;margin-top:14px}
.tile{background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:16px}
.tile h3{margin:0 0 6px;font-size:1.05rem}
.tile p{margin:0;color:var(--muted);font-size:.95rem}
details{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:12px 16px;margin:10px 0}
summary{cursor:pointer;font-weight:700}
details p{color:var(--muted);margin:8px 0 0}
kbd{display:inline-block;border:1px solid var(--line);border-bottom-width:2px;background:#fff;border-radius:6px;padding:0 8px;font:600 .85rem/1.6 ui-monospace,Menlo,Consolas,monospace;color:var(--text)}
footer{border-top:1px solid var(--line);margin-top:30px;padding:22px 0 40px;color:var(--muted);font-size:.9rem}
footer a{color:var(--muted);margin-right:14px}
.prose{max-width:760px;margin:24px auto 60px}
.prose h1{font-size:2rem;letter-spacing:-.01em}
.prose h2{margin-top:28px}
.prose li{margin:6px 0;color:var(--muted)}
.prose p{color:var(--muted)}
.cta{display:inline-block;margin-top:14px;background:linear-gradient(90deg,#6d4aff,#2563eb);color:#fff;text-decoration:none;font-weight:800;border-radius:12px;padding:12px 20px}

/* chat screen */
#chat{position:fixed;inset:0;background:var(--bg);display:flex;flex-direction:column;z-index:20}
#chat[hidden]{display:none}
.bar{display:flex;align-items:center;justify-content:space-between;padding:10px 14px;border-bottom:1px solid var(--line);background:#fff}
.bar .brand{font-size:1.05rem}
.bar .meta{color:var(--muted);font-size:.85rem}
.stage{flex:1;display:grid;grid-template-columns:1.4fr 1fr;min-height:0}
.stage.text{grid-template-columns:1fr}
.videos{position:relative;background:#0d0f16;min-height:0}
.stage.text .videos{display:none}
#remoteWrap{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;color:#a5aecb}
#remoteVideo{width:100%;height:100%;object-fit:contain;background:#0d0f16}
#remoteVideo.blur{filter:blur(28px)}
#localVideo{position:absolute;right:12px;bottom:12px;width:26%;max-width:200px;border-radius:12px;border:2px solid #fff;box-shadow:0 4px 18px rgba(0,0,0,.35);background:#111;transform:scaleX(-1)}
.panel{display:flex;flex-direction:column;min-height:0;border-left:1px solid var(--line);background:#fff}
.stage.text .panel{border-left:0;max-width:760px;width:100%;margin:0 auto}
#log{flex:1;overflow:auto;padding:14px;display:flex;flex-direction:column;gap:6px}
.msg{max-width:85%;padding:8px 12px;border-radius:14px;word-wrap:break-word;white-space:pre-wrap}
.msg.me{align-self:flex-end;background:var(--a);color:#fff}
.msg.them{align-self:flex-start;background:var(--panel2);color:var(--text)}
.msg.sys{align-self:center;background:transparent;color:var(--muted);font-size:.85rem;text-align:center}
#form{display:flex;gap:8px;padding:10px;border-top:1px solid var(--line)}
#form input{flex:1}
.actions{display:flex;gap:8px;flex-wrap:wrap;align-items:center;padding:10px;border-top:1px solid var(--line);background:var(--panel)}
.filters{display:flex;gap:8px;flex-wrap:wrap}
.actions .filters{margin-left:auto}
.fbtn{background:#fff;border:1px solid var(--line);color:var(--text);border-radius:999px;padding:8px 14px;cursor:pointer;font-size:.9rem}
.fbtn.on{border-color:var(--a);background:#6d4aff14;color:#4b2fd1;font-weight:700}
.toast{position:fixed;left:50%;bottom:28px;transform:translateX(-50%);background:#151826;color:#fff;padding:10px 16px;border-radius:10px;z-index:50;display:none;max-width:90vw}
dialog{background:#fff;color:var(--text);border:1px solid var(--line);border-radius:14px;padding:20px;max-width:380px;width:92%}
dialog::backdrop{background:#0008}
dialog .row{display:flex;gap:8px;justify-content:flex-end;margin-top:14px}
@media(max-width:760px){
  .stage{grid-template-columns:1fr;grid-template-rows:42% 58%}
  .panel{border-left:0;border-top:1px solid var(--line)}
  nav a{margin-left:10px}
  .actions .filters{margin-left:0}
}