:root{
  --bg:#f5f7fb;
  --panel:#ffffff;
  --line:#e7ebf2;
  --text:#1d2433;
  --muted:#778195;
  --primary:#2563eb;
  --primary-soft:#eef4ff;
  --danger:#e5484d;
  --success:#0f9f6e;
  --shadow:0 16px 50px rgba(15,23,42,.08);
  --radius:18px;
}
*{box-sizing:border-box}
html,body{height:100%;margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Arial,"Microsoft YaHei",sans-serif;color:var(--text);background:var(--bg)}
button,input,textarea,select{font:inherit}
button{border:0;cursor:pointer}
.hidden{display:none!important}
.mobile-only{display:none!important}
.error-text{color:var(--danger);font-size:13px;margin-top:10px;min-height:18px}

.login-wrap{min-height:100vh;display:grid;place-items:center;padding:24px;background:linear-gradient(135deg,#eef4ff,#f7f9fc)}
.login-card{width:min(420px,100%);background:var(--panel);border-radius:26px;box-shadow:var(--shadow);padding:34px;border:1px solid var(--line)}
.brand-circle,.rail-logo{width:48px;height:48px;border-radius:14px;background:linear-gradient(135deg,#2563eb,#14b8a6);color:white;font-weight:800;display:grid;place-items:center;letter-spacing:.5px}
.login-card h1{margin:18px 0 4px}.login-card p{margin:0 0 24px;color:var(--muted)}
.login-card label,.settings-grid label,.profile-body label{display:block;font-size:13px;color:var(--muted);margin:12px 0 6px}
input,textarea,select{width:100%;border:1px solid var(--line);border-radius:13px;padding:11px 12px;outline:0;background:#fff;color:var(--text)}
textarea{resize:vertical;line-height:1.45}
input:focus,textarea:focus,select:focus{border-color:#9bbcff;box-shadow:0 0 0 3px rgba(37,99,235,.12)}
.primary,.secondary,.danger,.ghost{border-radius:12px;padding:10px 14px;font-weight:700;white-space:nowrap}
.primary{background:var(--primary);color:#fff}.primary:hover{filter:brightness(.96)}
.secondary{background:#eef2f7;color:#263044}.danger{background:#fff0f0;color:var(--danger);border:1px solid #ffd2d2}.ghost{background:transparent;color:var(--muted)}
.full{width:100%;margin-top:16px}

.app{height:100vh;display:grid;grid-template-columns:84px 1fr;overflow:hidden}
.rail{background:#111827;color:white;display:flex;flex-direction:column;align-items:center;padding:14px 10px;gap:10px}
.rail-logo{width:44px;height:44px;border-radius:13px;margin-bottom:8px}
.rail-btn{width:62px;min-height:54px;border-radius:16px;background:transparent;color:#bdc7d8;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;font-size:18px}
.rail-btn span{font-size:11px}.rail-btn:hover,.rail-btn.active{background:rgba(255,255,255,.1);color:white}.rail-spacer{flex:1}
.workspace{min-width:0;overflow:hidden}.page{display:none;height:100%}.page.active{display:block}
.chat-layout{display:none;grid-template-columns:minmax(260px,340px) minmax(0,1fr) minmax(260px,320px);gap:1px;background:var(--line)}
.chat-layout.active{display:grid}
.contacts-pane,.conversation-pane,.profile-pane{background:var(--panel);min-width:0;height:100%;overflow:hidden}
.contacts-pane,.profile-pane{display:flex;flex-direction:column}
.pane-head,.chat-head,.card-head{padding:18px 20px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:14px}
.pane-head h2,.chat-head h2,.card-head h2{margin:0;font-size:18px}.pane-head small,.chat-head small,.card-head p{color:var(--muted);margin:3px 0 0;font-size:12px}
.search-box{padding:12px 14px;border-bottom:1px solid var(--line)}
.contact-list{overflow:auto;padding:8px}.contact-item{display:flex;align-items:center;gap:12px;padding:12px;border-radius:16px;cursor:pointer;position:relative}.contact-item:hover,.contact-item.active{background:var(--primary-soft)}
.avatar,.contact-avatar{width:42px;height:42px;flex:0 0 auto;border-radius:50%;background:#e7efff;color:var(--primary);font-weight:800;display:grid;place-items:center}.contact-body{min-width:0;flex:1}.contact-top{display:flex;justify-content:space-between;gap:8px}.contact-name{font-weight:800;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.contact-time{font-size:11px;color:var(--muted);white-space:nowrap}.contact-last{font-size:13px;color:var(--muted);overflow:hidden;text-overflow:ellipsis;white-space:nowrap;margin-top:3px}.unread{background:var(--danger);color:white;font-size:11px;border-radius:999px;padding:2px 7px;position:absolute;right:14px;bottom:12px}
.conversation-pane{position:relative}.empty-state{height:100%;display:grid;place-items:center;text-align:center;color:var(--muted);padding:28px}.empty-state div{font-size:48px}.empty-state h2{color:var(--text);margin:12px 0 6px}.active-chat{height:100%;display:flex;flex-direction:column}.chat-head{height:74px}.profile-toggle{display:none}.messages{flex:1;overflow:auto;padding:18px 22px;background:linear-gradient(180deg,#f8fafc,#f5f7fb)}
.msg-row{display:flex;margin:10px 0}.msg-row.outbound{justify-content:flex-end}.bubble{max-width:min(620px,78%);background:#fff;border:1px solid var(--line);border-radius:18px;padding:10px 12px;box-shadow:0 2px 10px rgba(15,23,42,.04)}.outbound .bubble{background:#e8f1ff;border-color:#d7e7ff}.msg-meta{font-size:11px;color:var(--muted);margin-top:6px;display:flex;gap:8px;justify-content:space-between}.msg-text{white-space:pre-wrap;line-height:1.45}.msg-img{max-width:260px;max-height:280px;border-radius:12px;display:block;cursor:zoom-in}.deleted-img{border:1px dashed #c9d1de;color:var(--muted);padding:18px;border-radius:12px;background:#fafafa}.translate-btn{font-size:12px;margin-top:8px;padding:5px 9px;border-radius:999px;background:#eef2f7;color:#334155}.translated{margin-top:8px;border-left:3px solid var(--primary);padding:8px 10px;background:#f8fbff;border-radius:10px;color:#334155;font-size:13px;white-space:pre-wrap}.composer{border-top:1px solid var(--line);padding:10px 14px;background:#fff}.quick-reply-bar{display:flex;gap:8px;overflow:auto;padding-bottom:8px}.quick-chip{border:1px solid var(--line);background:#fff;color:#334155;border-radius:999px;padding:6px 10px;font-size:12px}.composer textarea{min-height:52px;max-height:120px}.composer-actions{margin-top:8px;display:flex;justify-content:flex-end;gap:8px}
.profile-body{padding:20px;overflow:auto}.profile-avatar{width:70px;height:70px;border-radius:22px;background:var(--primary-soft);color:var(--primary);display:grid;place-items:center;font-size:28px;font-weight:800;margin:auto}.profile-body h3{text-align:center;margin:12px 0 3px}.profile-body p{text-align:center;color:var(--muted);margin:0 0 18px}.muted-box{margin:20px;padding:18px;border-radius:16px;background:#f8fafc;color:var(--muted)}
.settings-page{overflow:auto;padding:24px}.content-card{max-width:1100px;margin:0 auto 18px;background:var(--panel);border:1px solid var(--line);box-shadow:var(--shadow);border-radius:var(--radius);overflow:hidden}.form-grid,.settings-grid{padding:18px 20px;display:grid;gap:12px}.users-form{grid-template-columns:1fr 1fr 140px auto}.item-list{padding:0 20px 20px}.item{border:1px solid var(--line);border-radius:16px;padding:14px;margin-top:10px;display:flex;align-items:flex-start;justify-content:space-between;gap:12px}.item h4{margin:0 0 4px}.item p{margin:0;color:var(--muted);white-space:pre-wrap}.item-actions{display:flex;gap:8px}.hint-box{background:#f8fafc;border:1px solid var(--line);border-radius:14px;padding:12px;color:#334155;white-space:pre-wrap;line-height:1.45}.media-grid{padding:20px;display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:14px}.media-card{border:1px solid var(--line);border-radius:16px;overflow:hidden;background:#fff}.media-card img{width:100%;height:140px;object-fit:cover;display:block;cursor:zoom-in}.media-info{padding:10px;font-size:12px;color:var(--muted)}.media-info strong{display:block;color:var(--text);font-size:13px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.media-check{position:absolute}.media-thumb-wrap{position:relative}.media-thumb-wrap input{position:absolute;width:auto;top:8px;left:8px;transform:scale(1.2)}
.drawer{position:fixed;inset:0;background:rgba(15,23,42,.25);z-index:30;display:flex;justify-content:flex-end}.drawer-card{width:min(360px,100%);height:100%;background:#fff;box-shadow:var(--shadow);padding:18px}.drawer-head{display:flex;justify-content:space-between;align-items:center}.switch-line{display:flex;align-items:center;justify-content:space-between;padding:14px 0;border-bottom:1px solid var(--line)}.switch-line input{width:auto;transform:scale(1.2)}.toast-host{position:fixed;right:18px;top:18px;z-index:40;display:grid;gap:10px}.toast{background:#111827;color:#fff;border-radius:16px;padding:12px 14px;box-shadow:var(--shadow);min-width:240px}.toast small{color:#cbd5e1}.image-modal{position:fixed;inset:0;background:rgba(0,0,0,.82);z-index:50;display:grid;place-items:center;padding:24px}.image-modal img{max-width:94vw;max-height:90vh;border-radius:12px}.image-modal button{position:fixed;right:24px;top:18px;background:white;color:#111827;border-radius:999px;width:40px;height:40px;font-size:24px}

@media (max-width:1180px){
  .chat-layout{grid-template-columns:minmax(250px,320px) minmax(0,1fr)}
  .profile-pane{position:fixed;right:0;top:0;bottom:0;width:min(340px,92vw);z-index:20;box-shadow:var(--shadow);transform:translateX(105%);transition:.2s transform}
  .profile-pane.open{transform:translateX(0)}.profile-toggle{display:block}
}
@media (max-width:820px){
  .app{grid-template-columns:62px 1fr}.rail{padding:10px 6px}.rail-btn{width:50px}.rail-btn span{display:none}.rail-logo{width:42px;height:42px}
  .chat-layout{grid-template-columns:1fr}.contacts-pane{display:flex}.conversation-pane{display:none}.chat-layout.chat-open .contacts-pane{display:none}.chat-layout.chat-open .conversation-pane{display:block}.mobile-only{display:inline-flex!important}.settings-page{padding:14px}.users-form{grid-template-columns:1fr}.bubble{max-width:88%}.card-head{align-items:flex-start;flex-direction:column}.media-grid{grid-template-columns:repeat(auto-fill,minmax(140px,1fr));padding:14px}.msg-img{max-width:210px}.composer-actions{justify-content:stretch}.composer-actions button{flex:1}
}
@media (max-width:520px){
  .app{grid-template-columns:1fr}.rail{height:58px;position:fixed;left:0;right:0;bottom:0;top:auto;z-index:25;flex-direction:row;justify-content:space-around}.rail-logo,.rail-spacer{display:none}.rail-btn{min-height:46px}.workspace{padding-bottom:58px}.pane-head,.chat-head{padding:14px}.messages{padding:12px}.settings-page{padding:10px}.content-card{border-radius:14px}.toast-host{left:12px;right:12px;top:12px}.toast{min-width:0}
}