:root{
  --bg:#f4f6f5;--panel:#fff;--side:#eef3f1;--text:#1c2420;--muted:#6b7772;--line:#dde3e0;
  --accent:#1f6f5f;--accent-weak:#d9ece6;--mine:#e3f2ec;--hover:#f0f4f2;--danger:#c0392b;--badge:#e0493a;
  --shadow:0 2px 10px rgba(0,0,0,.08);
}
@media (prefers-color-scheme:dark){:root{
  --bg:#121614;--panel:#1a201d;--side:#161c19;--text:#e6ebe8;--muted:#98a39e;--line:#2a332f;
  --accent:#4fb39b;--accent-weak:#1f3a33;--mine:#213a32;--hover:#222a26;--shadow:0 2px 10px rgba(0,0,0,.4);
}}
*{box-sizing:border-box}
html,body{height:100%;margin:0;background:var(--bg);color:var(--text);font:15px/1.5 system-ui,-apple-system,"Segoe UI","Hiragino Sans","Yu Gothic UI","Noto Sans JP",sans-serif;-webkit-text-size-adjust:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer;padding:0}
input,textarea{font:inherit;color:inherit}
a{color:var(--accent)}
.hidden{display:none!important}

/* login */
.login{min-height:100%;display:flex;align-items:center;justify-content:center;padding:20px}
.login-card{background:var(--panel);padding:28px 26px;border-radius:14px;box-shadow:var(--shadow);width:min(360px,100%);display:flex;flex-direction:column;gap:12px}
.login-card h1{margin:0 0 6px;font-size:22px;color:var(--accent)}
label{display:flex;flex-direction:column;gap:4px;font-size:13px;color:var(--muted)}
label input{padding:10px 12px;border:1px solid var(--line);border-radius:8px;background:var(--bg);font-size:16px}
.primary{background:var(--accent);color:#fff;padding:10px 16px;border-radius:8px;font-weight:600}
.primary:disabled{opacity:.5}
.link{color:var(--accent);padding:4px 6px}
.icon{font-size:18px;padding:6px 8px;border-radius:8px;line-height:1}
.icon:hover{background:var(--hover)}
.error{color:var(--danger);font-size:13px;margin:0;min-height:1em}

/* layout */
.app{display:grid;grid-template-columns:270px 1fr;height:100dvh;height:100vh}
@supports (height:100dvh){.app{height:100dvh}}
.sidebar{background:var(--side);border-right:1px solid var(--line);display:flex;flex-direction:column;min-height:0}
.side-head{display:flex;align-items:center;justify-content:space-between;padding:12px 12px 6px}
.brand{font-weight:700;color:var(--accent)}
.search-box{padding:4px 10px 8px}
.search-box input{width:100%;padding:8px 10px;border:1px solid var(--line);border-radius:8px;background:var(--panel);font-size:14px}
.room-list{overflow:auto;flex:1 1 auto;min-height:80px}
.user-list{overflow:auto;flex:0 1 35%;min-height:60px}
.side-sec{padding:8px 12px 2px;font-size:12px;color:var(--muted);text-transform:none}
.room,.user{display:flex;align-items:center;gap:8px;padding:8px 12px;cursor:pointer;user-select:none}
.room:hover,.user:hover{background:var(--hover)}
.room.active{background:var(--accent-weak);font-weight:600}
.room .nm,.user .nm{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.badge{background:var(--badge);color:#fff;border-radius:10px;font-size:11px;padding:1px 7px;font-weight:700}
.dot{width:9px;height:9px;border-radius:50%;background:#b8c2bd;flex:none}
.dot.on{background:#2ecc71}
.side-foot{display:flex;align-items:center;gap:4px;padding:8px 10px;border-top:1px solid var(--line);font-size:13px;flex-wrap:wrap}
.side-foot .me{flex:1;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.backdrop{display:none}

.main{display:flex;flex-direction:column;min-width:0;min-height:0;position:relative;background:var(--panel)}
.main-head{display:flex;align-items:center;gap:8px;padding:10px 14px;border-bottom:1px solid var(--line);min-height:52px}
.menu{display:none}
.room-title{flex:1;min-width:0;display:flex;flex-direction:column}
#roomName{font-weight:700;font-size:16px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.sub{font-size:12px;color:var(--muted)}
.conn{width:10px;height:10px;border-radius:50%;background:#e67e22}
.conn.ok{background:#2ecc71}.conn.ng{background:var(--danger)}

/* messages */
.messages{flex:1;overflow-y:auto;overflow-x:hidden;padding:8px 14px 4px;scroll-behavior:auto;outline:0;overscroll-behavior:contain}
.load-more{text-align:center;color:var(--accent);cursor:pointer;padding:6px;font-size:13px}
.day{display:flex;align-items:center;gap:10px;color:var(--muted);font-size:12px;margin:14px 0 6px}
.day::before,.day::after{content:"";flex:1;border-top:1px solid var(--line)}
.unread-sep{color:var(--badge);font-size:12px;text-align:center;margin:8px 0;border-top:1px solid var(--badge);line-height:0}
.unread-sep span{background:var(--panel);padding:0 8px}
.msg{position:relative;display:grid;grid-template-columns:38px 1fr;gap:0 10px;padding:3px 6px 3px 2px;border-radius:8px}
.msg:hover{background:var(--hover)}
.msg .av{grid-column:1;grid-row:1/3}
.msg .head{grid-column:2;grid-row:1}
.msg .body{grid-column:2;grid-row:2}
.msg.cont .av,.msg.cont .head{display:none}
.av{width:34px;height:34px;border-radius:50%;background:var(--accent);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:14px;margin-top:3px;user-select:none}
.msg.mine .av{background:#5a8f7f}
.head{display:flex;gap:8px;align-items:baseline;font-size:13px}
.head .nm{font-weight:700}
.head .tm{color:var(--muted);font-size:12px}
.body{white-space:pre-wrap;word-break:break-word;overflow-wrap:anywhere}
.body .edited{color:var(--muted);font-size:11px;margin-left:6px}
.body.deleted{color:var(--muted);font-style:italic}
.reply-q{border-left:3px solid var(--accent);padding:2px 8px;margin:2px 0 4px;color:var(--muted);font-size:13px;background:var(--bg);border-radius:0 6px 6px 0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;cursor:pointer}
.reply-q b{color:var(--text)}
.atts{display:flex;flex-wrap:wrap;gap:8px;margin-top:6px}
.att-img{display:block;max-width:min(420px,100%);max-height:320px;border-radius:8px;border:1px solid var(--line);cursor:zoom-in;background:var(--bg)}
.att-file{display:flex;align-items:center;gap:8px;padding:8px 12px;border:1px solid var(--line);border-radius:8px;text-decoration:none;color:var(--text);background:var(--bg);max-width:100%}
.att-file .fn{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:260px}
.att-file .fs{color:var(--muted);font-size:12px;white-space:nowrap}
.att-file.expired{opacity:.6;font-style:italic}
.tools{position:absolute;right:8px;top:-12px;display:none;gap:2px;background:var(--panel);border:1px solid var(--line);border-radius:8px;box-shadow:var(--shadow);padding:2px;user-select:none}
.msg:hover .tools,.msg.show-tools .tools{display:flex}
.tools button{padding:3px 7px;border-radius:6px;font-size:14px}
.tools button:hover{background:var(--hover)}
.msg.hl{background:var(--accent-weak)}
.jump{position:absolute;right:16px;bottom:100px;background:var(--accent);color:#fff;padding:8px 14px;border-radius:20px;box-shadow:var(--shadow);font-weight:600}
.typing{height:18px;font-size:12px;color:var(--muted);padding:0 16px}

/* composer */
.composer{border-top:1px solid var(--line);padding:6px 10px calc(8px + env(safe-area-inset-bottom));background:var(--panel)}
.composer-row{display:flex;align-items:flex-end;gap:6px}
#input{flex:1;resize:none;max-height:40vh;padding:9px 12px;border:1px solid var(--line);border-radius:12px;background:var(--bg);line-height:1.45;font-size:16px}
.send{border-radius:12px;padding:9px 14px;font-size:16px}
.reply-bar{display:flex;align-items:center;gap:6px;font-size:13px;color:var(--muted);padding:2px 6px 6px}
.reply-bar span{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.attach-bar{display:flex;flex-wrap:wrap;gap:8px}
.attach-bar:not(:empty){padding:4px 0 8px}
.pend{position:relative;display:flex;align-items:center;gap:6px;border:1px solid var(--line);border-radius:8px;padding:4px 8px;font-size:13px;background:var(--bg);max-width:260px}
.pend img{width:44px;height:44px;object-fit:cover;border-radius:6px}
.pend .fn{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:150px}
.pend .bar{position:absolute;left:0;bottom:0;height:3px;background:var(--accent);border-radius:0 0 8px 8px;transition:width .2s}
.pend.err{border-color:var(--danger)}
.drop-hint{position:absolute;inset:0;background:rgba(31,111,95,.85);color:#fff;display:flex;align-items:center;justify-content:center;font-size:24px;font-weight:700;z-index:5;pointer-events:none}

/* search */
.search-results{position:absolute;inset:52px 0 0 0;background:var(--panel);overflow:auto;z-index:4;padding:8px 14px}
.sr{padding:8px;border-bottom:1px solid var(--line);cursor:pointer}
.sr:hover{background:var(--hover)}
.sr .meta{font-size:12px;color:var(--muted)}
.sr .txt{white-space:pre-wrap;word-break:break-word;max-height:4.5em;overflow:hidden}
mark{background:#ffe27a;color:#000;border-radius:2px}

/* lightbox */
.lightbox{position:fixed;inset:0;background:rgba(0,0,0,.9);display:flex;align-items:center;justify-content:center;z-index:50;cursor:zoom-out}
.lightbox img{max-width:96vw;max-height:92vh;object-fit:contain}
.lb-dl{position:absolute;top:14px;right:16px;color:#fff;background:rgba(255,255,255,.2);padding:6px 12px;border-radius:8px;text-decoration:none}

/* dialogs */
dialog{border:0;border-radius:14px;box-shadow:var(--shadow);background:var(--panel);color:var(--text);padding:0;max-width:min(520px,94vw);width:100%}
dialog::backdrop{background:rgba(0,0,0,.4)}
.dlg{padding:20px 22px;display:flex;flex-direction:column;gap:10px}
.dlg.wide{max-width:none}
.dlg h2{margin:0;font-size:18px}
.dlg h3{margin:10px 0 0;font-size:15px}
.dlg-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:6px}
.check-list{display:flex;flex-wrap:wrap;gap:6px 14px;max-height:30vh;overflow:auto}
.check-list label,.inline{flex-direction:row;align-items:center;gap:6px;font-size:14px;color:var(--text)}
.admin-table{width:100%;border-collapse:collapse;font-size:14px}
.admin-table th,.admin-table td{text-align:left;padding:6px 6px;border-bottom:1px solid var(--line)}
.admin-table button{color:var(--accent);padding:2px 6px}
.admin-add{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.admin-add input{padding:8px 10px;border:1px solid var(--line);border-radius:8px;background:var(--bg);flex:1 1 140px;font-size:15px}

.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);background:#222;color:#fff;padding:10px 16px;border-radius:10px;z-index:60;box-shadow:var(--shadow);font-size:14px;max-width:90vw}

/* mobile */
@media (max-width:760px){
  .app{grid-template-columns:1fr}
  .sidebar{position:fixed;inset:0 auto 0 0;width:min(300px,85vw);z-index:30;transform:translateX(-100%);transition:transform .2s;box-shadow:var(--shadow)}
  .sidebar.open{transform:none}
  .backdrop.open{display:block;position:fixed;inset:0;background:rgba(0,0,0,.35);z-index:29}
  .menu{display:inline-block}
  .messages{padding:6px 8px 4px}
  .msg{grid-template-columns:32px 1fr;gap:0 8px}
  .av{width:30px;height:30px;font-size:12px}
  .att-img{max-height:260px}
  .tools{display:flex;position:static;box-shadow:none;border:0;background:none;grid-column:2;margin-top:2px;visibility:hidden;height:0;overflow:hidden}
  .msg.show-tools .tools{visibility:visible;height:auto}
}