:root{--bg:#eef2f8;--surf:#fff;--text:#172033;--muted:#6a778b;--line:#dde4ee;--navy:#0b2a5b;--blue:#1f5fd6;--green:#16a36a;--gold:#d4a72c;--red:#d9382c;--amber:#ef8f0b;--in:#f5f7fb;--stu:#d8f3e2;--adm:#e9edf4;--sys:#fff3cd;--sysT:#7a5a00;--sh:0 10px 30px rgba(15,32,70,.10)}
[data-theme=dark]{--bg:#0a111e;--surf:#131d2f;--text:#e7edf8;--muted:#8d9bb3;--line:#24324b;--navy:#cfe0ff;--in:#0d1626;--stu:#14523a;--adm:#1e2c45;--sys:#3a3114;--sysT:#f0cf6b;--sh:0 10px 30px rgba(0,0,0,.5)}
*{box-sizing:border-box}
body{margin:0;font-family:"Segoe UI",system-ui,Arial,sans-serif;background:var(--bg);color:var(--text);transition:background .3s,color .3s}
body.student{min-height:100vh;display:flex;justify-content:center;padding:14px}
body.admin{height:100vh;overflow:hidden}
.container{width:100%;max-width:460px;animation:rise .45s ease both}
.brand{display:flex;align-items:center;gap:12px;padding:12px 14px;margin-bottom:14px;background:var(--surf);border:1px solid var(--line);border-bottom:3px solid var(--gold);border-radius:16px;box-shadow:var(--sh);text-align:left}
.brand img{width:52px;height:52px;border-radius:50%;object-fit:cover;background:#fff;border:2px solid var(--gold)}
.brand h1{margin:0;font-size:1.02rem;letter-spacing:.08em;color:var(--navy)}
.brand small{display:block;margin-top:2px;color:var(--muted);font-size:.78rem}
.brand button{margin-left:auto}
h2{text-align:center;margin:4px 0 14px;font-size:1.05rem;color:var(--navy)}
.card,#loginBox{background:var(--surf);border:1px solid var(--line);border-radius:18px;padding:20px;box-shadow:var(--sh)}
.tabs{display:flex;background:var(--in);border:1px solid var(--line);border-radius:12px;padding:4px;margin-bottom:14px}
.tab{flex:1;text-align:center;padding:9px;border-radius:9px;cursor:pointer;font-weight:600;color:var(--muted);transition:.2s}
.tab.active{background:var(--navy);color:#fff}
[data-theme=dark] .tab.active{color:#0b2a5b;background:#cfe0ff}
input[type=text],input[type=password],input[type=email]{width:100%;padding:12px 14px;margin-top:10px;border:1.5px solid var(--line);border-radius:10px;background:var(--in);color:var(--text);font-size:1rem;outline:none;transition:.2s}
input:focus{border-color:var(--blue);box-shadow:0 0 0 4px rgba(31,95,214,.16)}
button{--b:var(--blue);--d:#1648a8;font:inherit;font-weight:600;color:#fff;border:0;border-radius:10px;padding:11px 16px;background:var(--b);box-shadow:0 3px 0 var(--d);cursor:pointer;transition:transform .12s,box-shadow .12s,filter .2s}
button:hover{filter:brightness(1.07)}
button:active{transform:translateY(3px);box-shadow:none}
button:disabled{opacity:.55;cursor:not-allowed}
#submitBtn,#loginBtn{width:100%;margin-top:16px;--b:var(--green);--d:#0e7a4e}
#sendBtn{--b:var(--green);--d:#0e7a4e}
#logoutBtn{--b:var(--red);--d:#a1241b;padding:7px 12px;font-size:.85rem}
#attachBtn,#newQueryBtn,#unholdBtn,#holdBtn{--b:var(--amber);--d:#b06a00}
#resolveBtn{--b:var(--red);--d:#a1241b}
#newQueryBtn,#unholdBtn{display:none;width:100%;margin-top:10px}
#themeBtn,.themeBtn{width:40px;height:40px;padding:0;border-radius:50%;background:var(--in);color:var(--text);border:1px solid var(--line);box-shadow:0 3px 0 var(--line)}
#err,#loginErr{color:var(--red);font-size:.9rem;margin-top:10px;min-height:1.2em;word-break:break-word}
#appBox{display:none}
.topbar{display:flex;justify-content:space-between;align-items:center;gap:8px;margin-bottom:10px}
.topbar b{color:var(--navy);font-size:.95rem}
#banner{display:none;padding:9px;border-radius:10px;font-size:.9rem;text-align:center;margin-bottom:8px}
#banner.hold{display:block;background:var(--sys);color:var(--sysT)}
#banner.resolved{display:block;background:#d6f5e0;color:#146c3a}
[data-theme=dark] #banner.resolved{background:#16452b;color:#9ff0c0}
#chat-box{display:flex;flex-direction:column;overflow-y:auto;padding:12px;background:var(--surf);border:1px solid var(--line);border-radius:16px}
.student #chat-box{height:min(58vh,540px)}
.empty{margin:auto;color:var(--muted);text-align:center}
.msg{max-width:80%;margin:4px 0;padding:8px 12px;border-radius:14px;word-wrap:break-word;box-shadow:0 1px 3px rgba(0,0,0,.08)}
.msg.new{animation:pop .25s ease both}
.msg.student{align-self:flex-end;background:var(--stu);border-bottom-right-radius:4px}
.msg.admin{align-self:flex-start;background:var(--adm);border-bottom-left-radius:4px}
.admin .msg.student{align-self:flex-start;border-bottom-right-radius:14px;border-bottom-left-radius:4px}
.admin .msg.admin{align-self:flex-end;border-bottom-left-radius:14px;border-bottom-right-radius:4px}
.msg.system{align-self:center;background:var(--sys);color:var(--sysT);font-weight:600;font-size:.85rem;text-align:center}
.who{display:block;margin-bottom:3px;font-size:.72rem;font-weight:700;color:var(--muted)}
.time{display:block;margin-top:4px;text-align:right;font-size:.68rem;color:var(--muted)}
.chat-img{display:block;max-width:100%;border-radius:10px;cursor:pointer}
.chat-file{color:var(--blue);font-weight:600;text-decoration:none}
#uploadInfo{min-height:1em;margin-top:4px;font-size:.8rem;color:var(--muted)}
#msgArea{display:flex;gap:8px;align-items:center;margin-top:10px}
#msgInput{flex:1;min-width:0;margin:0}
#app{display:none}#app.on{display:flex}
.sidebar{width:310px;background:#0d2347;color:#fff;display:flex;flex-direction:column;z-index:1000;transition:left .3s}
.sb-head{padding:14px;display:flex;justify-content:space-between;align-items:center;gap:8px;border-bottom:1px solid rgba(255,255,255,.1)}
.sb-head h3{margin:0;font-size:1rem;letter-spacing:.04em}.sb-head>div{display:flex;gap:8px;align-items:center}
.mini{width:28px;height:28px;border-radius:50%;background:#fff;vertical-align:middle;margin-right:6px;border:2px solid var(--gold)}
.sidebar .tabs{margin:10px;background:rgba(255,255,255,.08);border-color:transparent}
.sidebar .tab{color:#b9c7e2;font-size:.85rem;padding:8px 4px}.sidebar .tab.active{background:var(--gold);color:#1b1500}
.sidebar #search{width:calc(100% - 20px);margin:0 10px 8px;background:rgba(255,255,255,.1);border-color:transparent;color:#fff}
#list{flex:1;overflow-y:auto}
.t-item{padding:11px 14px;border-bottom:1px solid rgba(255,255,255,.08);cursor:pointer;transition:background .15s}
.t-item:hover{background:rgba(255,255,255,.08)}.t-item.sel{background:rgba(212,167,44,.22);border-left:4px solid var(--gold)}
.t-top{display:flex;justify-content:space-between;align-items:center;font-weight:600;font-size:.92rem}
.t-prev{font-size:.8rem;opacity:.75;margin-top:3px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.badge{background:var(--red);color:#fff;border-radius:10px;padding:1px 7px;font-size:.75rem}
.none{padding:20px;text-align:center;opacity:.7;font-size:.9rem}
.main{flex:1;display:flex;flex-direction:column;padding:14px;min-width:0;height:100vh}
.head{display:flex;align-items:center;gap:8px;margin-bottom:10px;flex-wrap:wrap}
#title{flex:1;margin:0;text-align:left;font-size:1.1rem;min-width:120px}
#statusBadge{font-size:.8rem;padding:3px 10px;border-radius:10px;background:var(--in);border:1px solid var(--line);color:var(--text)}
.admin #chat-box{flex:1;display:none}
#placeholder{margin:auto;color:var(--muted)}
#inputSection{display:none;flex-direction:column;gap:8px;margin-top:10px}
#quick{display:flex;gap:6px;flex-wrap:wrap}
.qr{--b:var(--in);--d:var(--line);color:var(--text);border:1px solid var(--line);border-radius:16px;padding:5px 12px;font-size:.82rem;font-weight:500}
#loginBox{max-width:360px;margin:10vh auto 0}
#loginBox .brand{box-shadow:none;border:0;border-bottom:3px solid var(--gold);border-radius:0;padding:0 0 12px}
.menu-btn,.close-btn{display:none;background:transparent;color:var(--text);box-shadow:none;font-size:1.3rem;padding:4px 8px}
.close-btn{color:#fff}
@media (max-width:768px){.menu-btn,.close-btn{display:block}.sidebar{position:fixed;left:-100%;top:0;height:100%;width:86%;max-width:310px}.sidebar.active{left:0;box-shadow:4px 0 20px rgba(0,0,0,.5)}}
@keyframes rise{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}
@keyframes pop{from{opacity:0;transform:scale(.94) translateY(6px)}to{opacity:1;transform:none}}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}

/* ---- v4: reply, meta row, forgot/change password ---- */
.msg{position:relative}
.meta{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:4px}
.meta .time{margin:0 0 0 auto}
button.rbtn{background:none;box-shadow:none;color:var(--muted);padding:0 2px;font-size:.74rem;font-weight:600;border-radius:6px}
button.rbtn:hover{color:var(--blue);filter:none}
button.rbtn:active{transform:none;box-shadow:none}
.quote{border-left:3px solid var(--blue);background:rgba(0,0,0,.06);border-radius:6px;padding:4px 8px;margin-bottom:6px;font-size:.82rem;cursor:pointer}
[data-theme=dark] .quote{background:rgba(255,255,255,.08)}
.quote b{display:block;font-size:.7rem;color:var(--blue)}
.quote span{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:260px}
.reply-bar{display:none;align-items:center;gap:8px;margin-top:8px;padding:6px 8px 6px 10px;border-left:4px solid var(--blue);background:var(--in);border-radius:8px;font-size:.85rem}
.reply-bar.on{display:flex}
.reply-bar .rtxt{flex:1;min-width:0}
.reply-bar b{display:block;font-size:.72rem;color:var(--blue)}
.reply-bar span{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
button.rclose{--b:var(--in);--d:var(--line);color:var(--text);padding:2px 9px;box-shadow:none}
.msg.flash{animation:flash 1.4s ease}
@keyframes flash{0%,55%{box-shadow:0 0 0 3px var(--gold)}100%{box-shadow:0 1px 3px rgba(0,0,0,.08)}}
.link{display:block;text-align:center;margin-top:14px;color:var(--blue);font-weight:600;text-decoration:none;font-size:.9rem}
.sub{margin:0 0 6px;color:var(--navy);font-size:1.02rem}
.hint{margin:0 0 6px;color:var(--muted);font-size:.85rem;line-height:1.4}
.inline-card{background:var(--surf);border:1px solid var(--line);border-radius:14px;padding:12px;margin-bottom:10px}
.tb-actions{display:flex;gap:8px;align-items:center}
#pwBtn{--b:var(--in);--d:var(--line);color:var(--text);padding:7px 11px;font-size:.9rem}
#fSend,#pwSave{width:100%;margin-top:12px;--b:var(--green);--d:#0e7a4e}
#fMsg,#pwMsg{font-size:.88rem;margin-top:10px;min-height:1.1em}
.ok{color:#146c3a}.bad{color:var(--red)}
[data-theme=dark] .ok{color:#8fe3b3}
#boot{text-align:center;color:var(--muted)}
#chat-box.held .rbtn{display:none}

/* ---- v5: mobile app-style layout (header + send box fix, beech me chat scroll) ---- */
:root{--app-h:100dvh}
body.student.chatmode{height:var(--app-h);min-height:0;overflow:hidden;padding:max(8px,env(safe-area-inset-top)) 10px max(8px,env(safe-area-inset-bottom)) 10px;align-items:stretch;overscroll-behavior:none}
body.chatmode .container{display:flex;flex-direction:column;height:100%;max-width:560px;min-height:0}
body.chatmode h2{display:none}
body.chatmode .brand{flex:none;margin-bottom:8px;padding:6px 12px;gap:10px}
body.chatmode .brand img{width:38px;height:38px}
body.chatmode .brand h1{font-size:.92rem}
body.chatmode .brand small{font-size:.7rem;margin-top:0}
body.chatmode #themeBtn{width:36px;height:36px}
body.chatmode #appBox{flex:1;min-height:0;display:flex!important;flex-direction:column}
body.chatmode #appBox>*{flex:none}
body.chatmode #appBox>#chat-box{flex:1 1 auto;min-height:80px;height:auto;-webkit-overflow-scrolling:touch;overscroll-behavior:contain}
body.chatmode #uploadInfo{min-height:0;margin-top:2px}
body.chatmode #msgArea{margin-top:8px}
body.chatmode #newQueryBtn,body.chatmode #unholdBtn{margin-top:8px}
@media (max-height:520px){body.chatmode .brand small{display:none}body.chatmode .topbar{margin-bottom:6px}}

/* ---- v5: admin layout fix (header + reply box fix, beech me chat scroll) ---- */
body.admin{height:var(--app-h);overscroll-behavior:none}
body.admin #app.on{height:var(--app-h)}
body.admin .main{height:var(--app-h);padding-bottom:max(14px,env(safe-area-inset-bottom))}
body.admin .head{flex:none}
body.admin #chat-box{min-height:0;-webkit-overflow-scrolling:touch;overscroll-behavior:contain}
body.admin #placeholder{flex:1;display:flex;align-items:center;justify-content:center}
body.admin #inputSection{flex:none}
@media (max-width:768px){
  body.admin .main{padding:8px 10px}
  body.admin .head{margin-bottom:6px;flex-wrap:nowrap;gap:6px}
  body.admin #title{min-width:0;font-size:.95rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
  body.admin #statusBadge{white-space:nowrap;font-size:.72rem;padding:2px 8px}
  body.admin #holdBtn,body.admin #resolveBtn{padding:7px 9px;font-size:.78rem;white-space:nowrap}
  body.admin #inputSection{margin-top:6px;gap:6px}
  body.admin #quick{flex-wrap:nowrap;overflow-x:auto;scrollbar-width:none}
  body.admin #quick .qr{white-space:nowrap;flex:none}
  body.admin #uploadInfo{min-height:0;margin:0}
}

/* ---- v6: ticks + typing ---- */
.tick{display:inline-block;margin-left:5px;font-size:.78rem;font-weight:700;letter-spacing:-3px;color:var(--muted);vertical-align:baseline}
.tick.wait{letter-spacing:0;font-size:.62rem;opacity:.7}
.tick.seen{color:#34b7f1}
#typing{height:20px;flex:none;padding:3px 8px 0;font-size:.8rem;font-style:italic;color:var(--muted);visibility:hidden}
#typing.on{visibility:visible;animation:blink 1.2s ease-in-out infinite}
@keyframes blink{50%{opacity:.45}}

/* ---- v7: instant password reset ---- */
.passbox{margin-top:12px;padding:12px;border:1.5px dashed var(--green);border-radius:12px;text-align:center;background:var(--in);font-size:.92rem}
.passbox code{display:block;font-size:1.5rem;letter-spacing:.12em;font-weight:700;margin:6px 0 10px;user-select:all;word-break:break-all}
.passbox button{margin:2px}
#fInstant{width:100%;margin-top:14px;--b:var(--green);--d:#0e7a4e}
#pinSave{width:100%;margin-top:10px;--b:var(--green);--d:#0e7a4e}
#fMsg2,#pinMsg{font-size:.88rem;margin-top:10px;min-height:1.1em}

/* ---- v8: admin online/offline, block ---- */
#presence{display:none;flex:none;margin:0 0 8px;padding:7px 11px;border-radius:10px;font-size:.82rem;font-weight:600;line-height:1.35;border:1px solid var(--line)}
#presence.on{display:block}
#presence.online{background:#d6f5e0;color:#146c3a;border-color:transparent}
#presence.offline{background:#fde4e1;color:#a1241b;border-color:transparent}
[data-theme=dark] #presence.online{background:#16452b;color:#9ff0c0}
[data-theme=dark] #presence.offline{background:#4a1f1b;color:#ffb4ab}
#blockedBox{text-align:center}
#blockedLogout{margin-top:14px;--b:var(--red);--d:#a1241b}
#presWrap{padding:0 10px 8px;position:relative}
#presBtn{width:100%;display:flex;align-items:center;justify-content:space-between;gap:8px;text-align:left;--b:rgba(255,255,255,.1);--d:rgba(0,0,0,.3);font-size:.86rem;padding:9px 12px}
#presBtn.off{--b:#7a2a24;--d:#4d1814}
#presBtn small{opacity:.8;font-weight:500}
#presMenu{display:none;margin-top:8px;padding:8px;border-radius:12px;background:rgba(255,255,255,.08);flex-direction:column;gap:6px}
#presMenu.open{display:flex}
#presMenu button{--b:rgba(255,255,255,.14);--d:rgba(0,0,0,.3);font-size:.82rem;padding:8px 10px;text-align:left}
#presMenu .pt{display:flex;align-items:center;gap:6px;flex-wrap:wrap;font-size:.8rem;color:#cdd8ee;margin-top:4px}
#presMenu select{background:rgba(255,255,255,.12);color:#fff;border:1px solid rgba(255,255,255,.2);border-radius:8px;padding:5px 6px;font-size:.8rem}
#presMenu select option{color:#111}
#presMenu .pt button{--b:var(--green);--d:#0e7a4e;padding:6px 10px}
#blockBtn{--b:#4b5563;--d:#1f2937;display:none}
.t-item .unb{margin-top:6px;--b:var(--green);--d:#0e7a4e;padding:5px 10px;font-size:.78rem}
.t-item .rsn{font-size:.76rem;opacity:.75;margin-top:2px}
@media (max-width:768px){body.admin #blockBtn{padding:7px 9px;font-size:.78rem;white-space:nowrap}}

/* ---- v9: Telegram password / link ---- */
#fTg,#tgLinkBtn{width:100%;margin-top:10px;--b:#229ed9;--d:#1a7aa6}
#fTgMsg,#tgMsg{font-size:.88rem;margin-top:10px;min-height:1.1em}