:root{--bg:#0a0a0a;--bg-secondary:#141414;--bg-tertiary:#1e1e1e;--text:#e5e5e5;--text-secondary:#888;--accent:#3b82f6;--accent-hover:#2563eb;--danger:#ef4444;--success:#22c55e;--border:#2a2a2a;--radius:12px}*{margin:0;padding:0;box-sizing:border-box}body,html{height:100%;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased}button,input,textarea{font-family:inherit;font-size:inherit}button{cursor:pointer;border:none;background:none;color:inherit}a{color:var(--accent);text-decoration:none}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#333;border-radius:3px}.container{max-width:480px;margin:0 auto;height:100vh;display:flex;flex-direction:column;background:var(--bg);overscroll-behavior-y:contain}.header{padding:16px 20px;background:var(--bg-secondary);border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;flex-shrink:0}.header h1{font-size:18px;font-weight:600}.btn{padding:10px 20px;border-radius:8px;font-size:14px;font-weight:500;transition:all .2s}.btn-primary{background:var(--accent);color:#fff}.btn-primary:hover{background:var(--accent-hover)}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.btn-danger{background:var(--danger);color:#fff}.btn-sm{padding:6px 12px;font-size:12px}.input{width:100%;padding:12px 16px;background:var(--bg-tertiary);border:1px solid var(--border);border-radius:8px;color:var(--text);font-size:14px;outline:none;transition:border-color .2s}.input:focus{border-color:var(--accent)}.input-group{margin-bottom:16px}.input-group label{display:block;margin-bottom:6px;font-size:13px;color:var(--text-secondary)}.error-msg{color:var(--danger);font-size:13px;margin-top:8px}.badge{display:inline-block;padding:2px 8px;border-radius:12px;font-size:11px;font-weight:600}.badge-encrypted{background:rgba(34,197,94,.15);color:var(--success)}.message-list{flex:1 1;overflow-y:auto;padding:16px 20px}.message{margin-bottom:12px;max-width:80%}.message.sent{margin-left:auto}.message-bubble{padding:10px 14px;border-radius:16px;font-size:14px;line-height:1.5;word-break:break-word}.message.sent .message-bubble{background:var(--accent);color:#fff;border-bottom-right-radius:4px}.message.received .message-bubble{background:var(--bg-tertiary);border-bottom-left-radius:4px}.message-sender{font-size:11px;color:var(--text-secondary);margin-bottom:4px}.message-time{font-size:10px;color:var(--text-secondary);margin-top:4px;text-align:right}.chat-input-area{padding:12px 20px;background:var(--bg-secondary);border-top:1px solid var(--border);display:flex;gap:8px;align-items:center;flex-shrink:0}.chat-input-area input{flex:1 1}.chat-input-area button{padding:10px 16px;background:var(--accent);color:#fff;border-radius:8px;font-weight:500;white-space:nowrap}.room-list{flex:1 1;overflow-y:auto}.room-item{display:flex;align-items:center;padding:14px 20px;border-bottom:1px solid var(--border);cursor:pointer;transition:background .2s}.room-item:hover{background:var(--bg-secondary)}.room-avatar{width:44px;height:44px;border-radius:50%;background:var(--bg-tertiary);display:flex;align-items:center;justify-content:center;font-size:18px;margin-right:12px;flex-shrink:0}.room-info{flex:1 1;min-width:0}.room-name{font-size:15px;font-weight:500;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.room-last{font-size:13px;color:var(--text-secondary);margin-top:2px}.modal-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.7);display:flex;align-items:center;justify-content:center;z-index:100;padding:20px}.modal{background:var(--bg-secondary);border-radius:var(--radius);padding:24px;width:100%;max-width:400px;max-height:80vh;overflow-y:auto}.modal h2{margin-bottom:16px;font-size:18px}.user-list-item{display:flex;align-items:center;padding:10px 0;border-bottom:1px solid var(--border);cursor:pointer}.user-list-item:hover{background:var(--bg-tertiary);margin:0 -8px;padding:10px 8px;border-radius:8px}.admin-table{width:100%;border-collapse:collapse;font-size:13px}.admin-table td,.admin-table th{padding:10px 12px;text-align:left;border-bottom:1px solid var(--border)}.admin-table th{color:var(--text-secondary);font-weight:500}.online-dot{width:8px;height:8px;border-radius:50%;background:var(--success);display:inline-block;margin-left:6px}.loading{display:flex;align-items:center;justify-content:center;padding:40px;color:var(--text-secondary)}.nav-tabs{display:flex;background:var(--bg-secondary);border-top:1px solid var(--border);flex-shrink:0}.nav-tab{flex:1 1;padding:12px;text-align:center;font-size:12px;color:var(--text-secondary);transition:color .2s}.nav-tab.active{color:var(--accent)}