:root{
  --bg:#f3f5f8; --panel:#fff; --line:#e3e7ee; --text:#1c2430; --muted:#6b7686;
  --brand:#1f6feb; --brand-dark:#1859bd; --mine:#dcebff; --theirs:#fff; --danger:#d1344b; --ok:#1a9d5a;
  --radius:12px;
}
@media (prefers-color-scheme:dark){
  :root{--bg:#10151c; --panel:#18202a; --line:#2a3441; --text:#e8edf3; --muted:#8c98a8;
        --brand:#4c8dff; --brand-dark:#3b78e0; --mine:#1d3a63; --theirs:#212b38; --danger:#ff6b7f; --ok:#3ac47d;}
}
*{box-sizing:border-box}
html,body{height:100%;margin:0}
body{font-family:Tahoma,"Segoe UI","Vazirmatn",system-ui,sans-serif;background:var(--bg);color:var(--text);font-size:15px;line-height:1.6}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
.hidden{display:none!important}

/* buttons / inputs */
.btn{background:var(--brand);color:#fff;border:0;border-radius:10px;padding:8px 16px}
.btn:hover{background:var(--brand-dark)}
.btn.ghost{background:transparent;color:var(--text);border:1px solid var(--line)}
.btn.ghost:hover{background:var(--bg)}
.btn.danger{background:var(--danger)}
.btn.sm{padding:4px 10px;font-size:13px}
.btn:disabled{opacity:.5;cursor:not-allowed}
input[type=text],input[type=password],input[type=search],input[type=datetime-local],input[type=date],select,textarea{
  width:100%;background:var(--panel);border:1px solid var(--line);border-radius:10px;padding:8px 12px;outline:none}
input:focus,select:focus,textarea:focus{border-color:var(--brand)}
label{display:block;margin:10px 0 4px;color:var(--muted);font-size:13px}
.ltr{direction:ltr;unicode-bidi:plaintext;text-align:left}
.muted{color:var(--muted)}
.err{color:var(--danger);min-height:1.4em;font-size:14px}

/* login */
.login-wrap{min-height:100%;display:grid;place-items:center;padding:16px}
.login-card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:28px;width:100%;max-width:360px;box-shadow:0 8px 30px rgba(0,0,0,.06)}
.login-card h1{margin:0 0 4px;font-size:22px}
.login-card .btn{width:100%;margin-top:14px;padding:10px}

/* app layout */
.app{display:flex;height:100%;height:100dvh}
.side{width:300px;flex:none;background:var(--panel);border-inline-end:1px solid var(--line);display:flex;flex-direction:column;min-height:0}
.side-head{padding:12px 14px;border-bottom:1px solid var(--line);display:flex;gap:8px;align-items:center;justify-content:space-between}
.side-head b{font-size:16px}
.side-actions{display:flex;gap:6px;padding:10px 12px;flex-wrap:wrap;border-bottom:1px solid var(--line)}
.side-list{overflow:auto;flex:1;padding:6px 6px 14px}
.sec-title{display:flex;justify-content:space-between;align-items:center;color:var(--muted);font-size:12.5px;padding:12px 10px 4px}
.sec-title button{background:none;border:0;color:var(--brand);font-size:13px;padding:0}
.item{display:flex;align-items:center;gap:8px;padding:8px 10px;border-radius:10px;cursor:pointer;border:0;background:none;width:100%;text-align:start}
.item:hover{background:var(--bg)}
.item.active{background:var(--mine)}
.item .nm{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.item.off .nm{opacity:.5;text-decoration:line-through}
.dot{width:9px;height:9px;border-radius:50%;background:var(--line);flex:none}
.dot.on{background:var(--ok)}
.badge{background:var(--danger);color:#fff;border-radius:999px;font-size:12px;min-width:20px;text-align:center;padding:0 6px}
.ico{flex:none;width:22px;text-align:center}

.main{flex:1;display:flex;flex-direction:column;min-width:0;min-height:0}
.main-head{padding:10px 14px;background:var(--panel);border-bottom:1px solid var(--line);display:flex;align-items:center;gap:10px}
.main-head h2{margin:0;font-size:16px;flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.main-head .sub{color:var(--muted);font-size:12.5px}
.back{display:none}

.msgs{flex:1;overflow:auto;padding:14px;display:flex;flex-direction:column;gap:6px;min-height:0}
.day{align-self:center;color:var(--muted);font-size:12px;background:var(--panel);border:1px solid var(--line);border-radius:999px;padding:1px 12px;margin:8px 0 2px}
.msg{max-width:min(620px,85%);padding:8px 12px;border-radius:14px;background:var(--theirs);border:1px solid var(--line);word-break:break-word}
.msg.mine{background:var(--mine);border-color:transparent;align-self:flex-start}   /* RTL: flex-start = right */
.msg.theirs{align-self:flex-end}
.msg .who{font-size:12.5px;color:var(--brand);font-weight:700}
.msg .tag{font-size:11.5px;color:var(--muted)}
.msg .body{white-space:pre-wrap;unicode-bidi:plaintext}
.msg .time{font-size:11px;color:var(--muted);margin-top:2px;text-align:end}
.more-btn{align-self:center}
.empty{margin:auto;color:var(--muted);text-align:center;padding:30px}

.composer{background:var(--panel);border-top:1px solid var(--line);padding:10px 12px}
.composer .target{font-size:12.5px;color:var(--muted);margin-bottom:6px}
.composer .row{display:flex;gap:8px;align-items:flex-end}
.composer textarea{resize:none;max-height:140px;min-height:42px}

/* modal */
.modal-bg{position:fixed;inset:0;background:rgba(0,0,0,.45);display:grid;place-items:center;padding:12px;z-index:50}
.modal{background:var(--panel);border-radius:16px;padding:18px;width:100%;max-width:520px;max-height:92dvh;overflow:auto;border:1px solid var(--line)}
.modal h3{margin:0 0 6px}
.modal .actions{display:flex;gap:8px;justify-content:flex-start;margin-top:16px;flex-wrap:wrap}
.checklist{border:1px solid var(--line);border-radius:10px;max-height:260px;overflow:auto;padding:4px}
.checklist label{display:flex;gap:8px;align-items:center;margin:0;padding:6px 8px;color:var(--text);font-size:14.5px;cursor:pointer;border-radius:8px}
.checklist label:hover{background:var(--bg)}
.checklist input{width:auto}
table.t{width:100%;border-collapse:collapse;font-size:14px}
table.t th,table.t td{padding:6px 8px;border-bottom:1px solid var(--line);text-align:start}
.cred{font-family:Consolas,monospace;direction:ltr;unicode-bidi:plaintext}
.tabs{display:flex;gap:4px;padding:8px 10px;overflow:auto;background:var(--panel);border-bottom:1px solid var(--line)}
.tab{border:1px solid var(--line);background:none;border-radius:999px;padding:4px 14px;white-space:nowrap}
.tab.active{background:var(--brand);color:#fff;border-color:var(--brand)}
.tab .badge{margin-inline-start:6px}
.toast{position:fixed;bottom:18px;inset-inline:0;margin:auto;width:max-content;max-width:90%;background:#222;color:#fff;padding:8px 18px;border-radius:999px;z-index:99}
.filters{display:grid;grid-template-columns:1fr 1fr;gap:8px}
.filters .full{grid-column:1/-1}

@media (max-width:760px){
  .side{width:100%;border:0}
  .app.in-thread .side{display:none}
  .app:not(.in-thread) .main{display:none}
  .back{display:inline-block}
  .msg{max-width:92%}
}
.modal.wide{max-width:760px}

/* ---- Viom look ---- */
.brand{display:inline-flex;align-items:center;gap:8px;font-size:17px}
.brand img{border-radius:8px;display:block}
.head-btns{display:inline-flex;gap:6px;align-items:center}
.logo-lg{display:block;margin:0 auto 6px;border-radius:16px}
.login-card h1{text-align:center}
.login-card .muted{text-align:center}
.who-me{flex:1;text-align:end;font-weight:400;color:var(--muted);font-size:14px}

.msgs{background:var(--chat-bg)}
:root{--chat-bg:#e7edf5}
@media (prefers-color-scheme:dark){:root{--chat-bg:#0d1218}}
.msg{box-shadow:0 1px 1px rgba(0,0,0,.05)}

.item{padding:8px 10px;gap:10px}
.av{position:relative;flex:none;width:42px;height:42px;border-radius:50%;color:#fff;display:grid;place-items:center;font-weight:700;font-size:17px}
.av.all{background:var(--brand)}
.av .on-dot{position:absolute;inset-inline-start:0;bottom:0;width:11px;height:11px;border-radius:50%;background:var(--ok);border:2px solid var(--panel)}
.item .col{flex:1;min-width:0;display:flex;flex-direction:column;line-height:1.35}
.item .pv{color:var(--muted);font-size:13px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;unicode-bidi:plaintext}
.item .meta{display:flex;flex-direction:column;align-items:flex-end;gap:3px;flex:none;min-width:34px}
.item .tm{color:var(--muted);font-size:11.5px}
.item.off .nm{text-decoration:none;opacity:.55}
.tick{margin-inline-start:6px;letter-spacing:-2px;font-size:12px;color:var(--muted)}
.tick.seen{color:var(--brand)}

/* ---- Vyom sky theme ---- */
:root{--brand:#2f7bff;--brand-dark:#1f5fe0;--mine:#d6e8ff;--chat-bg:linear-gradient(180deg,#e3efff,#f5f9ff)}
@media (prefers-color-scheme:dark){
  :root{--brand:#5b9dff;--brand-dark:#3f82ee;--mine:#1c3b7c;
        --chat-bg:radial-gradient(1.5px 1.5px at 12% 18%,#fff9,transparent),radial-gradient(1px 1px at 38% 62%,#fff8,transparent),
                  radial-gradient(1.5px 1.5px at 71% 28%,#fff9,transparent),radial-gradient(1px 1px at 86% 74%,#fff7,transparent),
                  radial-gradient(1px 1px at 55% 12%,#fff8,transparent),linear-gradient(180deg,#070d26,#0f1c47)}
}
.msgs{background:var(--chat-bg);background-attachment:local}
.login-wrap{background:radial-gradient(2px 2px at 15% 20%,#fff,transparent),radial-gradient(1.5px 1.5px at 80% 15%,#fff,transparent),
  radial-gradient(1.5px 1.5px at 62% 38%,#fffc,transparent),radial-gradient(2px 2px at 30% 55%,#fffb,transparent),
  radial-gradient(1.5px 1.5px at 90% 60%,#fffb,transparent),linear-gradient(180deg,#0a1442 0%,#1f4fb8 60%,#7cc4ff 100%)}
.login-card{background:rgba(255,255,255,.96);color:#1c2430}
.login-card .muted,.login-card label{color:#5c6778}
.login-card input{background:#fff;color:#1c2430;border-color:#d5dbe6}
.login-card h1 .latin{font-size:14px;font-weight:400;color:#2f7bff;letter-spacing:2px;margin-inline-start:4px}
.tagline{text-align:center;color:#5c6778;font-size:13.5px;margin-bottom:6px}
.side-head,.main-head{background:linear-gradient(90deg,var(--panel),var(--panel))}
.btn{background:linear-gradient(135deg,#3b86ff,#1f5fe0)}
.btn.ghost,.btn.danger{background:transparent}
.btn.danger{background:var(--danger)}

/* media, search highlight */
.media-img{display:block;max-width:min(280px,100%);max-height:320px;border-radius:10px;cursor:zoom-in;margin:2px 0 4px;background:var(--bg)}
.media-audio{display:block;width:250px;max-width:100%;margin:2px 0 4px}
.media-full{display:block;max-width:100%;max-height:72vh;margin:auto;border-radius:8px}
.composer .icon{padding:6px 10px;font-size:17px;line-height:1.2}
.composer .icon.rec{background:var(--danger);color:#fff;border-color:var(--danger);font-size:14px}
mark{background:#ffe08a;color:#1c2430;border-radius:3px;padding:0 1px}
.msg.hit{cursor:pointer}
.msg.hit:hover{outline:2px solid var(--brand)}
a.btn{text-decoration:none;display:inline-block}
.media-file{display:flex;align-items:center;gap:10px;max-width:280px;margin:2px 0 4px;padding:8px 10px;border-radius:10px;border:1px solid var(--line);background:var(--bg);color:inherit;text-decoration:none}
.media-file .ic{font-size:26px;line-height:1}
.media-file .meta{display:flex;flex-direction:column;min-width:0}
.media-file .nm{font-size:13.5px;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;direction:ltr;text-align:right}
.media-file .sz{font-size:11.5px;color:var(--muted)}
.dl{display:inline-block;font-size:12px;color:var(--brand);text-decoration:none;margin-bottom:2px}
.dl-full{display:block;width:max-content;margin:10px auto 0;text-decoration:none}
.act{background:none;border:0;padding:0 4px;margin-inline-end:6px;font-size:13px;line-height:1;cursor:pointer;opacity:.55}
.act:hover{opacity:1}
.msg.deleted{opacity:.6}
.msg.deleted .body{text-decoration:line-through}
.media-gone{font-size:12.5px;color:var(--muted);font-style:italic;margin:2px 0 4px}
.install-bar{position:fixed;top:8px;inset-inline:0;margin:auto;width:max-content;max-width:94%;display:flex;gap:6px;align-items:center;background:var(--panel);border:1px solid var(--line);border-radius:999px;padding:5px 8px;z-index:90;box-shadow:0 4px 14px rgba(0,0,0,.18)}

.av img{width:100%;height:100%;border-radius:50%;object-fit:cover;display:block}
.av.big{width:72px;height:72px;font-size:28px}
.prof-top{display:flex;align-items:center;gap:12px;margin-bottom:10px}
h4.perm{margin:14px 0 2px;padding-top:10px;border-top:1px dashed var(--line);font-size:14px}
.req{border:1px solid var(--line);border-radius:12px;padding:10px;margin-bottom:10px}
.req-btns{display:flex;gap:6px;flex-wrap:wrap;margin-top:8px}
.login-card .btn.ghost{margin-top:8px}
.login-card .first-hint{margin-top:16px;text-align:center;font-size:13.5px;color:#5c6778}
.login-card .btn.first-btn{margin-top:6px;background:#fff;color:#1f6feb;border:2px solid #1f6feb;font-weight:700}
.login-card .btn.ghost{color:#1c2430;border-color:#c4ccd9;background:#fff}
.room-bar{display:block;width:100%;border:0;border-bottom:1px solid var(--line);background:var(--panel);color:var(--brand);padding:7px 12px;font-size:13px;cursor:pointer;text-align:start}
.av.sm{display:inline-grid;width:22px;height:22px;font-size:11px;vertical-align:middle}
.members{display:flex;flex-direction:column;gap:8px;max-height:55vh;overflow:auto}
.member{display:flex;align-items:center;gap:10px}
.member .av{width:36px;height:36px;font-size:15px}
.quote{display:flex;flex-direction:column;gap:2px;border-inline-start:3px solid var(--brand);background:rgba(127,127,127,.12);border-radius:8px;padding:4px 8px;margin:2px 0 6px;font-size:12.5px;cursor:pointer;max-width:100%}
.quote span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;opacity:.85}
.reply-bar{display:flex;align-items:center;justify-content:space-between;gap:8px;font-size:13px;padding:6px 10px;margin-bottom:6px;border-inline-start:3px solid var(--brand);background:var(--bg);border-radius:8px}
.reply-bar span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.pin-bar{display:flex;flex-direction:column;gap:2px;padding:4px 10px;border-bottom:1px solid var(--line);background:var(--panel)}
.pin-bar .pin{background:none;border:0;color:var(--text);text-align:start;font-size:13px;padding:3px 0;cursor:pointer;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.edited{font-size:11px;opacity:.7;margin-inline-end:6px;background:none;border:0;color:inherit;padding:0;cursor:default}
button.edited{cursor:pointer;text-decoration:underline dotted}
.msg.flash{outline:2px solid var(--brand);outline-offset:2px}
.search-res{max-height:50vh;overflow:auto;margin-top:8px;display:flex;flex-direction:column;gap:8px}
.res{border:1px solid var(--line);border-radius:10px;padding:8px;white-space:pre-wrap}