:root{--green:#075e54;--bright:#128c7e;--mint:#dcf8c6;--ink:#172b32;--muted:#64777b;--line:#dce3e4;--paper:#fff;--rail:#f8faf9;--wall:#efeae2;--bar:#f0f2f5;--bubble:#fff;--sent:#d9fdd3;--shadow:0 12px 52px #163b3920;color-scheme:light}
:root[data-theme=dark]{--green:#075e54;--bright:#27c5a8;--mint:#144d42;--ink:#e8eef0;--muted:#a5b5ba;--line:#2b3c44;--paper:#111e25;--rail:#14232b;--wall:#0b141a;--bar:#1f2c34;--bubble:#202f37;--sent:#005c4b;--shadow:0 12px 52px #0004;color-scheme:dark}
*{box-sizing:border-box}body{margin:0;background:#dce5df;color:var(--ink);font:15px/1.7 Tahoma,"Segoe UI",Arial,sans-serif}body::before{content:"";position:fixed;inset:0 0 auto;height:150px;background:var(--green);z-index:-1}button,input,textarea{font:inherit}button,a{touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:default;opacity:.55}a{color:var(--bright);text-underline-offset:4px}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible{outline:3px solid #e9b34b;outline-offset:2px}[hidden]{display:none!important}.skip{position:fixed;top:-100px;right:12px;z-index:200;background:var(--paper);padding:12px}.skip:focus{top:5px}.app{max-width:1440px;display:grid;grid-template-columns:360px minmax(0,1fr);height:calc(100dvh - 40px);min-height:420px;margin:20px auto;background:var(--paper);box-shadow:var(--shadow);border-radius:10px;overflow:hidden}.sidebar{display:flex;flex-direction:column;min-width:0;border-inline-end:1px solid var(--line);background:var(--paper);overflow:hidden}.brandbar{height:82px;padding:14px 17px;background:var(--bar);display:flex;align-items:center;gap:10px;flex:none}.brand{flex:1;min-width:0}.brand strong{display:block;font-size:18px;line-height:1.5}.brand small{display:block;color:var(--muted);font-size:11px}.avatar{width:42px;height:42px;border-radius:50%;background:#c5e8df;display:grid;place-items:center;flex:none;color:#075e54;font-size:19px;font-weight:bold}.avatar.logo{background:var(--green);color:#fff}.icon{width:42px;height:42px;display:inline-flex;align-items:center;justify-content:center;border:0;border-radius:50%;background:transparent;color:var(--muted);flex:none;text-decoration:none}.icon:hover{background:#6c85841a}.icon svg{width:22px;height:22px;stroke:currentColor;fill:none;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}.row{display:flex;align-items:center;gap:8px}.grow{flex:1;min-width:0}.searchbox{padding:13px 14px 8px;position:relative}.searchbox input{width:100%;height:43px;border:1px solid transparent;border-radius:9px;background:var(--bar);padding:10px 38px 10px 12px;color:var(--ink);min-width:0}.searchbox svg{position:absolute;right:27px;top:26px;width:17px;height:17px;stroke:var(--muted);fill:none;stroke-width:2}.filters{display:flex;gap:7px;padding:4px 14px 12px;flex-wrap:wrap}.filter{min-height:36px;border:0;border-radius:20px;padding:6px 13px;color:var(--muted);background:var(--bar);font-size:12px}.filter.active{background:#d9f2e9;color:#075e54;font-weight:bold}:root[data-theme=dark] .filter.active{background:#15594b;color:#b5f5d7}.rail-hint{color:var(--muted);font-size:11px;margin:0;padding:1px 17px 9px;border-bottom:1px solid var(--line)}.threads{flex:1;overflow-y:auto;overscroll-behavior:contain;min-height:0}.thread{display:flex;gap:12px;align-items:center;text-align:right;width:100%;min-height:91px;padding:13px 16px;background:transparent;border:0;border-bottom:1px solid var(--line);color:var(--ink)}.thread:hover{background:var(--rail)}.thread.active{background:var(--bar)}.thread .avatar{width:46px;height:46px;font-size:16px}.thread-top{display:flex;align-items:center;gap:8px;justify-content:space-between}.thread-name{font-weight:bold;font-size:14px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:185px}.thread time{font-size:10px;color:var(--muted);white-space:nowrap}.thread-text{font-size:12px;color:var(--muted);overflow:hidden;text-overflow:ellipsis;white-space:nowrap;margin:4px 0}.tag{font-size:10px;color:var(--bright);display:inline-block}.tag.pending{color:#a56a14}.unread{width:9px;height:9px;flex:none;border-radius:50%;background:var(--bright)}.count{background:var(--bright);color:#fff;border-radius:20px;font-size:10px;padding:1px 6px}.rail-footer{border-top:1px solid var(--line);padding:12px 15px;flex:none;background:var(--rail)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:10px 17px;border-radius:9px;border:0;background:var(--green);color:white;font-weight:bold;text-decoration:none;font-size:14px}.btn svg{width:20px;height:20px;stroke:currentColor;fill:none;stroke-width:2}.btn.wide{width:100%}.btn.soft{color:var(--bright);background:var(--bar)}.btn.danger{background:#aa3647;color:white}.loadmore{border:0;border-radius:8px;background:var(--bar);color:var(--bright);min-height:40px;display:block;padding:8px 15px;margin:12px auto;font-size:12px}.rail-status{font-size:12px;color:var(--muted);padding:8px 15px;white-space:pre-wrap;overflow-wrap:anywhere}.rail-status:empty{display:none}.error{color:#bd4355!important}.conversation{display:flex;flex-direction:column;min-width:0;min-height:0;background:var(--wall);position:relative}.conversation::before{content:"";position:absolute;inset:0;background-image:radial-gradient(#77948918 1px,transparent 1px),radial-gradient(#77948910 2px,transparent 2px);background-size:24px 24px,67px 67px;pointer-events:none}.chathead{height:82px;padding:12px 20px;display:flex;align-items:center;gap:12px;background:var(--bar);z-index:1;flex:none;border-bottom:1px solid var(--line)}.chathead h1{font-size:16px;margin:0;line-height:1.5;white-space:nowrap;text-overflow:ellipsis;overflow:hidden}.chathead p{font-size:11px;color:var(--muted);margin:3px 0 0}.back{display:none}.empty-chat{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:35px;z-index:1;border-bottom:5px solid var(--bright)}.empty-logo{height:90px;width:90px;border-radius:50%;background:#c4ddd2;color:var(--green);display:grid;place-items:center;margin-bottom:22px}.empty-logo svg{width:48px;height:48px;stroke:currentColor;fill:none;stroke-width:1.3}.empty-chat h1{font-size:28px;margin:0 0 12px;font-weight:500}.empty-chat p{max-width:400px;color:var(--muted);font-size:14px;margin:0 0 20px}.empty-chat small{display:block;font-size:11px;color:var(--muted);margin-top:28px}.thread-view{display:flex;flex-direction:column;flex:1;min-height:0;z-index:1}.notice{border-radius:8px;background:#fff1c4;color:#645326;padding:9px 14px;font-size:12px;max-width:620px;margin:12px auto;text-align:center;line-height:1.9;overflow-wrap:anywhere}:root[data-theme=dark] .notice{background:#333329;color:#e6dda5}.service{background:var(--paper);padding:8px 15px;font-size:12px;color:var(--muted);z-index:1;flex:none}.service:empty{display:none}.messages{flex:1;overflow-y:auto;min-height:0;display:flex;flex-direction:column;gap:7px;padding:20px clamp(16px,5vw,70px);overscroll-behavior:contain}.message{max-width:min(82%,620px);min-width:135px;align-self:flex-start;background:var(--bubble);border-radius:9px 0 9px 9px;padding:8px 12px 5px;box-shadow:0 1px 2px #00000015;position:relative;flex:none;overflow-wrap:anywhere}.message.teacher{align-self:flex-end;background:var(--sent);border-radius:0 9px 9px 9px}.admin .message.teacher{align-self:flex-start;border-radius:9px 0 9px 9px}.admin .message.student{align-self:flex-end;border-radius:0 9px 9px 9px}.speaker{font-size:11px;font-weight:bold;color:var(--bright);margin-bottom:3px}.body-text{white-space:pre-wrap;line-height:1.95;font-size:14px;overflow-wrap:anywhere}.body-text a{word-break:break-word}.message-foot{display:flex;gap:7px;justify-content:flex-end;align-items:center;color:var(--muted);font-size:10px;margin-top:3px;min-height:18px}.delivered{font-size:13px;color:var(--bright)}.day{align-self:center;border-radius:7px;background:var(--paper);box-shadow:0 1px 2px #0001;font-size:10px;color:var(--muted);padding:4px 12px;margin:10px 0}.message.hidden-message{opacity:.6;border:1px dashed #b74b5e}.moderate{border:0;color:var(--muted);font-size:10px;background:transparent;min-height:24px;padding:0 4px;text-decoration:underline}.image-load{display:block;min-height:38px;margin:6px 0;background:var(--bar);border:1px solid var(--line);border-radius:7px;color:var(--bright);padding:7px 10px;font-size:12px}.message-image{display:block;max-width:100%;max-height:340px;object-fit:contain;border-radius:7px;margin:7px 0;cursor:zoom-in}.composer-wrap{flex:none;background:var(--bar);z-index:2;padding-bottom:env(safe-area-inset-bottom)}.composer{display:flex;align-items:flex-end;gap:8px;padding:10px 13px}.composer textarea{flex:1;width:0;min-width:0;min-height:46px;max-height:128px;resize:none;overflow:auto;border:1px solid transparent;border-radius:12px;background:var(--paper);color:var(--ink);padding:10px 14px;line-height:1.7;outline-offset:0}.send{background:var(--green);color:#fff;width:46px;height:46px;border-radius:50%;border:0;flex:none;display:grid;place-items:center}.send svg{stroke:currentColor;fill:none;width:23px;height:23px;stroke-width:2}.compose-hint{color:var(--muted);font-size:11px;padding:0 20px 9px;text-align:center}.compose-status{padding:0 20px 8px;font-size:12px;color:var(--bright);white-space:pre-wrap}.compose-status:empty{display:none}.selected-image{padding:10px 18px;display:flex;align-items:center;gap:12px;border-bottom:1px solid var(--line);font-size:12px}.selected-image img{width:52px;height:52px;object-fit:cover;border-radius:7px}.readonly{font-size:12px;text-align:center;color:var(--muted);padding:14px 18px;line-height:1.9}.readonly .btn{font-size:12px;min-height:36px;margin-inline-start:6px}.overlay{position:fixed;inset:0;z-index:100;background:#0a29277d;backdrop-filter:blur(3px);padding:20px;display:flex;align-items:center;justify-content:center}.dialog{background:var(--paper);border-radius:16px;max-width:480px;width:100%;padding:25px;max-height:90dvh;overflow:auto;box-shadow:var(--shadow)}.dialog h2{font-size:21px;margin:0}.dialog p{font-size:13px;color:var(--muted)}.dialog label{display:block;font-size:13px;font-weight:bold;margin:15px 0 6px}.dialog input,.dialog textarea{border:1px solid var(--line);border-radius:9px;background:var(--rail);padding:11px 12px;width:100%;color:var(--ink);min-height:45px}.dialog textarea{min-height:140px;resize:vertical;line-height:1.9}.dialog-actions{display:flex;gap:9px;align-items:center;margin-top:20px}.dialog-status{font-size:12px;margin-top:13px;white-space:pre-wrap;color:var(--bright)}.privacy-note{font-size:12px;line-height:1.9;background:var(--bar);padding:11px 13px;border-radius:8px}.field-count{font-size:10px;color:var(--muted);text-align:left}.status-line{padding:8px 15px;font-size:11px;color:var(--muted);background:var(--rail);border-bottom:1px solid var(--line)}.status-line:empty{display:none}.private-tag{color:#a56a14;font-size:10px}.image-modal{position:fixed;inset:0;z-index:150;display:flex;align-items:center;justify-content:center;background:#061014ec;padding:60px 20px}.image-modal img{max-width:100%;max-height:83dvh}.image-modal .btn{position:absolute;top:15px;left:20px}.counter-info{font-size:11px;color:var(--muted);padding:0 18px 9px}.hp{position:fixed;width:1px;height:1px;right:0;top:0;overflow:hidden;clip-path:inset(50%)}.offline{color:#c07a16}.auth-title{display:flex;justify-content:space-between;gap:12px}.question-file{font-size:11px;color:var(--muted);overflow-wrap:anywhere;margin:7px 0}.end-mark{font-size:10px;color:var(--muted);text-align:center;margin-top:15px}.teacher-label{font-size:11px;color:var(--bright)}
@media(min-width:1700px){.app{margin:28px auto;height:calc(100dvh - 56px)}}
@media(max-width:900px){.app{grid-template-columns:315px minmax(0,1fr);margin:0;height:100dvh;border-radius:0}.thread-name{max-width:150px}.chathead{padding:12px 15px}.messages{padding:16px 20px}.message{max-width:88%}}
@media(max-width:680px){body{background:var(--paper)}.app{display:block;height:var(--app-height,100dvh);min-height:0;margin:0;border-radius:0}.sidebar,.conversation{height:100%}.conversation{display:none}.app.is-open .sidebar{display:none}.app.is-open .conversation{display:flex}.back{display:inline-flex;width:35px}.brandbar,.chathead{height:76px}.chathead{padding:10px 8px;gap:7px}.chathead .avatar{width:36px;height:36px;font-size:15px}.chathead h1{font-size:14px}.chathead p{font-size:10px}.chathead .icon{width:37px;height:40px}.chathead p{max-width:220px;white-space:nowrap;text-overflow:ellipsis;overflow:hidden}.thread-name{max-width:calc(100vw - 155px)}.messages{padding:12px 13px}.message{max-width:90%;padding:7px 11px 4px}.body-text{font-size:14px}.composer{padding:8px;gap:5px}.composer .icon{width:37px;height:46px}.compose-hint{padding-bottom:8px;font-size:10px}.overlay{padding:12px}.dialog{padding:20px;max-height:calc(var(--app-height,100dvh) - 24px)}.dialog h2{font-size:19px}.dialog textarea{min-height:110px}.rail-footer{padding-bottom:calc(12px + env(safe-area-inset-bottom))}.empty-chat{display:none}.service{font-size:11px}.count{font-size:10px}.conversation .notice{max-width:100%;font-size:11px}.empty-chat h1{font-size:24px}}
@media(prefers-reduced-motion:no-preference){button,a{transition:background .15s}}@media print{.sidebar,.composer-wrap,.chathead .icon,.service,.loadmore,.moderate{display:none!important}.app{display:block;height:auto;margin:0;box-shadow:none}.conversation,.thread-view,.messages{display:block;height:auto;overflow:visible;background:#fff}.message{break-inside:avoid;max-width:90%;margin:15px}.chathead{background:#fff}.day{text-align:center}}
.avatar svg{width:24px;height:24px;stroke:currentColor;fill:none;stroke-width:1.7}

.brand strong{font-size:17px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.brand small{font-size:10px;line-height:1.5}.brandbar{padding-top:12px;padding-bottom:12px}