:root{--bg:#F5F6F8;--surface:#fff;--sunken:#EDF0F4;--line:#D8DEE6;--line-strong:#C3CBD6;--ink:#13233F;--muted:#56647C;--faint:#8A96A8;--cobalt:#2450D6;--cobalt-ink:#1B3DA6;--wash:#E8EEFD;--danger:#B42318;--warn:#9A5B00;--ok:#1F7A4D;--r:8px;--rc:12px;--shadow:0 1px 2px rgba(19,35,63,.06);--serif:Charter,"Iowan Old Style",Georgia,serif;--mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{background:var(--bg);color:var(--ink);font:15px/1.5 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
h1,h2{font-family:var(--serif);font-weight:600;margin:0}
a{color:var(--cobalt-ink)}
.mono{font-family:var(--mono)}
[hidden]{display:none!important}
:focus-visible{outline:2px solid var(--cobalt);outline-offset:2px}
.app{display:grid;grid-template-columns:260px 1fr;height:100vh;height:100dvh}
.sidebar{background:var(--surface);border-right:1px solid var(--line);padding:18px 14px;display:flex;flex-direction:column;gap:14px;overflow:auto}
.brand{font-family:var(--serif);font-size:22px;font-weight:600;display:flex;align-items:center;gap:10px}
.mark{width:22px;height:22px;border-radius:6px;background:var(--cobalt);display:inline-block}
.channel-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:2px}
.channel-list button{all:unset;box-sizing:border-box;display:block;width:100%;padding:8px 10px;border-radius:var(--r);cursor:pointer}
.channel-list button:hover{background:var(--sunken)}
.channel-list button[aria-current=true]{background:var(--wash);color:var(--cobalt-ink);font-weight:600}
.channel-list small{display:block;color:var(--muted);font-weight:400}
.fine{color:var(--faint);font-size:12.5px;margin-top:auto}
.main{min-width:0;display:flex;flex-direction:column;overflow:hidden}
.btn{appearance:none;border:1px solid var(--cobalt);background:var(--cobalt);color:#fff;border-radius:var(--r);padding:9px 16px;font:inherit;font-weight:600;cursor:pointer}
.btn:hover{background:var(--cobalt-ink)}
.btn:disabled{opacity:.55;cursor:default}
.btn.small{padding:5px 11px;font-size:13.5px}
.btn.ghost{background:transparent;color:var(--cobalt-ink);border-color:var(--line-strong)}
.btn.ghost:hover{background:var(--sunken)}
.btn.danger{background:transparent;color:var(--danger);border-color:#E7B4AE}
.btn.danger:hover{background:#FDF0EE}
.btn.full{width:100%}
.landing{overflow:auto;padding:48px 40px;max-width:980px;width:100%;margin:0 auto}
.hero h1{font-size:40px}
.hero p{color:var(--muted);font-size:17px;max-width:620px}
.cards{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin:28px 0}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--rc);padding:22px;box-shadow:var(--shadow);display:flex;flex-direction:column;gap:12px}
label{display:flex;flex-direction:column;gap:4px;font-size:13.5px;color:var(--muted);font-weight:500}
input,select,textarea{font:inherit;color:var(--ink);background:var(--surface);border:1px solid var(--line-strong);border-radius:var(--r);padding:8px 10px}
input:focus,select:focus,textarea:focus{border-color:var(--cobalt);outline:none;box-shadow:0 0 0 3px var(--wash)}
.form-error{color:var(--danger);margin:0;min-height:1.2em;font-size:13.5px}
.facts{color:var(--muted);padding-left:18px}
.room{display:flex;flex-direction:column;height:100%;min-height:0}
.room-head{display:flex;align-items:center;gap:14px;padding:12px 20px;background:var(--surface);border-bottom:1px solid var(--line)}
.room-title{min-width:0;flex:1}
.room-title h1{font-size:20px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.meta{margin:0;color:var(--muted);font-size:13px}
.room-actions{display:flex;gap:8px}
.conn{font-size:12.5px;color:var(--muted);white-space:nowrap}
.conn.ok::before{content:"● ";color:var(--ok)}
.conn.bad::before{content:"● ";color:var(--warn)}
.room-body{flex:1;display:grid;grid-template-columns:1fr 220px;min-height:0}
.messages{overflow:auto;padding:20px 24px;display:flex;flex-direction:column;gap:14px}
.people{border-left:1px solid var(--line);padding:16px;overflow:auto;background:var(--surface)}
.people h2{font-size:15px;margin-bottom:8px}
.people ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:6px}
.people li{display:flex;justify-content:space-between;gap:8px;font-size:14px}
.role{font-size:11.5px;color:var(--muted);background:var(--sunken);border-radius:999px;padding:1px 8px;align-self:center}
.msg{max-width:760px}
.msg .who{font-weight:650;margin-right:8px}
.msg .when{color:var(--faint);font-size:12px}
.msg .body{white-space:pre-wrap;overflow-wrap:anywhere;margin-top:2px}
.msg.mine .who{color:var(--cobalt-ink)}
.sys{color:var(--muted);font-size:13px;font-style:italic;text-align:center}
.doc{margin-top:6px;background:var(--surface);border:1px solid var(--line);border-radius:var(--rc);box-shadow:var(--shadow);max-width:460px;overflow:hidden}
.doc .doc-preview{background:var(--sunken);border-bottom:1px solid var(--line)}
.doc .doc-preview img{display:block;max-width:100%;max-height:320px;margin:0 auto;cursor:zoom-in}
.doc pre{margin:0;padding:12px 14px;font:12.5px/1.45 var(--mono);white-space:pre-wrap;overflow-wrap:anywhere;max-height:220px;overflow:hidden;color:var(--ink)}
.doc .pdf-thumb{display:flex;align-items:center;justify-content:center;gap:10px;height:120px;color:var(--danger);font-weight:700;font-family:var(--serif);font-size:22px}
.doc .doc-foot{display:flex;align-items:center;gap:10px;padding:10px 14px}
.doc .doc-name{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-weight:600}
.doc .doc-sub{color:var(--muted);font-size:12.5px;display:block;font-weight:400}
.badge{font:700 11px var(--mono);background:var(--wash);color:var(--cobalt-ink);border-radius:6px;padding:6px 7px;text-transform:uppercase}
.composer{display:flex;gap:10px;align-items:flex-end;padding:12px 20px;background:var(--surface);border-top:1px solid var(--line)}
.composer textarea{flex:1;resize:none;max-height:180px}
.attach{display:inline-flex;align-items:center}
.composer-note{margin:0;padding:0 20px 8px;background:var(--surface);color:var(--muted);font-size:12.5px;min-height:1.4em}
.composer-note.error{color:var(--danger)}
.dialog{border:1px solid var(--line);border-radius:var(--rc);padding:22px;max-width:480px;width:92vw;color:var(--ink);box-shadow:0 12px 40px rgba(19,35,63,.18)}
.dialog::backdrop{background:rgba(19,35,63,.35)}
.dialog form{display:flex;flex-direction:column;gap:12px}
.dialog .row{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.dialog-actions{display:flex;justify-content:flex-end;gap:8px}
.invite-result{background:var(--wash);border-radius:var(--r);padding:12px;display:flex;flex-direction:column;gap:8px}
.invite-result p{margin:0;font-size:13.5px}
.invite-result code{overflow-wrap:anywhere;font-size:12.5px;user-select:all}
.dialog.wide{max-width:960px;height:88vh;padding:0;display:flex;flex-direction:column}
.dialog.wide:not([open]){display:none}
.pdf-head{display:flex;justify-content:space-between;align-items:center;padding:10px 14px;border-bottom:1px solid var(--line)}
.pdf-wrap{flex:1}
.pdf-wrap iframe,.pdf-wrap object{width:100%;height:100%;border:0}
.menu-btn{display:none;appearance:none;border:1px solid var(--line-strong);background:var(--surface);border-radius:var(--r);padding:4px 10px;font-size:18px;color:var(--ink);cursor:pointer}
@media (max-width:820px){
  .app{grid-template-columns:1fr}
  .sidebar{position:fixed;inset:0 auto 0 0;width:80vw;max-width:300px;z-index:10;transform:translateX(-100%);transition:transform .2s;box-shadow:0 0 40px rgba(19,35,63,.2)}
  .app.nav-open .sidebar{transform:none}
  .menu-btn{display:inline-block}
  .cards{grid-template-columns:1fr}
  .landing{padding:20px}
  .room-body{grid-template-columns:1fr}
  .people{display:none}
  .room-head{flex-wrap:wrap;padding:10px 12px}
  .messages{padding:14px}
}