:root{--bg:#f7f7fb;--fg:#1d1d27;--mut:#62627a;--card:#fff;--line:#e3e3ee;--acc:#5b4bdb;--accl:#ecebff;--me:#5b4bdb;--bot:#fff;--err:#b42318;--errbg:#fef3f2}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;font:16px/1.55 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;background:var(--bg);color:var(--fg)}
a{color:var(--acc)}.wrap{max-width:1100px;margin:0 auto;padding:0 20px}
.top{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:5}
.bar{display:flex;justify-content:space-between;align-items:center;height:56px;gap:12px}
.brand{font-weight:700;text-decoration:none;color:var(--fg)}nav a{margin-left:16px;text-decoration:none;color:var(--mut);font-size:15px}
.hero{padding:40px 20px 8px}h1{font-size:clamp(26px,4vw,40px);line-height:1.15;margin:0 0 10px}
.lead{font-size:18px;color:var(--mut);margin:0}.disclaimer{font-size:13px;color:var(--mut);margin-top:10px}
h2{font-size:24px;margin:40px 0 16px}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:18px 20px}
.card h3{margin:0 0 8px;font-size:17px}.card ol,.card ul{margin:0;padding-left:20px}.card li{margin:4px 0}
.card.info{background:var(--accl);border-color:#d6d3ff}.card.info ul{list-style:none;padding:0}
.src{font-size:13px;color:var(--mut)}
.privacy{background:#ecfdf3;border:1px solid #abefc6;color:#05603a;padding:12px 16px;border-radius:12px;margin:0 0 16px}
.drop{border:2px dashed #b9b4f5;background:#fff;border-radius:16px;padding:28px;text-align:center;cursor:pointer;transition:.15s}
.drop.over,.drop:focus{border-color:var(--acc);background:var(--accl);outline:none}
.drop-title{font-size:18px;margin:0 0 6px}
.btn{display:inline-block;background:var(--acc);color:#fff;border:0;border-radius:10px;padding:9px 16px;font:inherit;font-size:15px;cursor:pointer}
.btn.ghost{background:#fff;color:var(--acc);border:1px solid var(--acc);margin-left:6px}
.btn.small{padding:6px 10px;font-size:13px}
.status{margin:12px 0}.status .ok{color:#05603a}.status .err{background:var(--errbg);color:var(--err);border:1px solid #fecdca;padding:14px 16px;border-radius:12px}
.status .err b{display:block;font-size:17px;margin-bottom:4px}
.app{display:grid;grid-template-columns:320px 1fr;gap:16px;margin-top:8px;min-height:480px}
.side,.chat{background:#fff;border:1px solid var(--line);border-radius:14px}
.side{padding:12px;display:flex;flex-direction:column;gap:10px;max-height:640px;overflow:auto}
#q{width:100%;padding:9px 12px;border:1px solid var(--line);border-radius:10px;font:inherit}
.dl-all{display:flex;gap:6px;flex-wrap:wrap}
.grp h4{margin:10px 4px 4px;font-size:13px;text-transform:uppercase;letter-spacing:.04em;color:var(--mut)}
.conv{display:block;width:100%;text-align:left;background:none;border:0;border-radius:10px;padding:8px 10px;font:inherit;cursor:pointer}
.conv:hover{background:var(--bg)}.conv.active{background:var(--accl)}.conv small{display:block;color:var(--mut);font-size:12px}
.chat{display:flex;flex-direction:column;max-height:640px}
.chat-head{padding:12px 16px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;gap:8px;flex-wrap:wrap}
.chat-head h3{margin:0;font-size:17px}.msgs{padding:16px;overflow:auto;display:flex;flex-direction:column;gap:10px;background:var(--bg);flex:1;border-radius:0 0 14px 14px}
.msg{max-width:78%;padding:10px 14px;border-radius:16px;white-space:pre-wrap;word-wrap:break-word;background:var(--bot);border:1px solid var(--line)}
.msg.me{align-self:flex-end;background:var(--me);color:#fff;border-color:var(--me)}
.msg .who{display:block;font-size:12px;font-weight:600;opacity:.75;margin-bottom:2px}
mark{background:#fde68a;color:inherit;border-radius:3px}
.empty{color:var(--mut);padding:24px;text-align:center;margin:auto}
.note{font-size:12px;color:var(--mut);margin-top:10px}
details{background:#fff;border:1px solid var(--line);border-radius:12px;padding:12px 16px;margin-bottom:10px}
summary{font-weight:600;cursor:pointer}details p{margin:8px 0 0;color:#3b3b4f}
.foot{font-size:13px;color:var(--mut);padding:30px 20px 50px}
.back{display:none}
@media(max-width:820px){.cards{grid-template-columns:1fr}.app{grid-template-columns:1fr}nav a{margin-left:10px;font-size:14px}
 .app.reading .side{display:none}.app:not(.reading) .chat{display:none}.back{display:inline-block}.msg{max-width:88%}.side,.chat{max-height:none}.msgs{max-height:70vh}}
@media(max-width:420px){nav a:first-child{display:none}.btn.ghost{margin:8px 0 0}}
section[id],#chat{scroll-margin-top:64px}