:root{--bg: #F0F7FF;--white: #FFFFFF;--primary: #5B9BD5;--primary-hover: #4A8AC4;--primary-light: #E3F2FD;--text: #333333;--text-secondary: #888888;--success: #4CAF50;--danger: #F44336;--border: #E8EDF2;--shadow: 0 1px 3px rgba(0, 0, 0, .08);--radius-sm: 8px;--radius: 12px;--radius-lg: 16px;--transition: .2s ease}*{margin:0;padding:0;box-sizing:border-box}html,body,#root{height:100%;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,sans-serif;font-size:16px;color:var(--text);background:var(--bg);-webkit-font-smoothing:antialiased}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}.btn{display:inline-flex;align-items:center;justify-content:center;padding:12px 24px;border:none;border-radius:var(--radius-sm);font-size:16px;font-weight:500;cursor:pointer;transition:background var(--transition),transform var(--transition);gap:8px}.btn:active{transform:scale(.97)}.btn:disabled{opacity:.5;cursor:not-allowed}.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover:not(:disabled){background:var(--primary-hover)}.btn-outline{background:transparent;color:var(--primary);border:1.5px solid var(--primary)}.btn-outline:hover:not(:disabled){background:var(--primary-light)}.btn-danger{background:var(--danger);color:#fff}.btn-block{width:100%}.input-group{margin-bottom:16px}.input-group label{display:block;margin-bottom:6px;font-size:14px;color:var(--text-secondary);font-weight:500}.input-group input{width:100%;padding:12px 14px;border:1.5px solid var(--border);border-radius:var(--radius-sm);font-size:16px;transition:border-color var(--transition);outline:none;background:var(--white)}.input-group input:focus{border-color:var(--primary);box-shadow:0 0 0 3px #5b9bd526}.input-group input::placeholder{color:#c0c8d2}.tabs{display:flex;border-bottom:2px solid var(--border);margin-bottom:24px}.tab{flex:1;padding:12px;text-align:center;cursor:pointer;color:var(--text-secondary);font-size:15px;font-weight:500;border:none;background:none;border-bottom:2px solid transparent;margin-bottom:-2px;transition:color var(--transition),border-color var(--transition)}.tab:hover{color:var(--text)}.tab.active{color:var(--primary);border-bottom-color:var(--primary)}.card{background:var(--white);border-radius:var(--radius);box-shadow:var(--shadow);padding:24px}.page-center{display:flex;align-items:center;justify-content:center;min-height:100%;padding:24px}.message-bubble{max-width:75%;padding:12px 16px;border-radius:var(--radius-lg);font-size:15px;line-height:1.5;word-break:break-word;position:relative}.message-sent{background:var(--primary);color:#fff;align-self:flex-end;border-bottom-right-radius:4px}.message-received{background:var(--white);border:1px solid var(--border);align-self:flex-start;border-bottom-left-radius:4px}.message-time{font-size:12px;margin-top:4px;opacity:.7}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#ccd5de;border-radius:3px}::-webkit-scrollbar-thumb:hover{background:#b0bbc5}.mobile-nav{display:flex;background:var(--white);border-top:1px solid var(--border);padding:8px 0;padding-bottom:max(8px,env(safe-area-inset-bottom))}.mobile-nav-item{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;color:var(--text-secondary);font-size:11px;text-decoration:none;padding:6px 0;border:none;background:none;cursor:pointer;transition:color var(--transition)}.mobile-nav-item.active{color:var(--primary)}.mobile-nav-item svg{width:24px;height:24px}.sidebar{width:220px;background:var(--white);border-right:1px solid var(--border);display:flex;flex-direction:column;padding:16px;flex-shrink:0}.sidebar-logo{font-size:20px;font-weight:700;color:var(--primary);padding:12px;margin-bottom:8px}.sidebar-nav{display:flex;flex-direction:column;gap:4px;flex:1}.sidebar-item{display:flex;align-items:center;gap:10px;padding:12px;border-radius:var(--radius-sm);color:var(--text-secondary);text-decoration:none;font-size:15px;transition:background var(--transition),color var(--transition)}.sidebar-item:hover{background:var(--primary-light);color:var(--text)}.sidebar-item.active{background:var(--primary-light);color:var(--primary);font-weight:600}.sidebar-item svg{width:20px;height:20px;flex-shrink:0}.toast{position:fixed;top:16px;left:50%;transform:translate(-50%);background:var(--text);color:#fff;padding:12px 24px;border-radius:var(--radius-sm);font-size:14px;z-index:1000;animation:toast-in .3s ease}.toast-error{background:var(--danger)}.toast-success{background:var(--success)}@keyframes toast-in{0%{opacity:0;transform:translate(-50%) translateY(-10px)}to{opacity:1;transform:translate(-50%) translateY(0)}}[data-theme=dark]{--bg: #1a1d23;--white: #252830;--primary: #6db3e8;--primary-hover: #5ba3da;--primary-light: #1e3040;--text: #e0e0e0;--text-secondary: #999;--border: #333840;--shadow: 0 1px 3px rgba(0,0,0,.3)}[data-theme=dark] .message-received{background:#2a2d35;border-color:#333840}[data-theme=dark] .sidebar-logo{color:var(--primary)}[data-theme=dark] input,[data-theme=dark] textarea,[data-theme=dark] select{color:var(--text);background:#1e2128;border-color:#333840}[data-theme=dark] input:focus,[data-theme=dark] textarea:focus{background:#1e2128;border-color:var(--primary)}[data-theme=dark] input::placeholder,[data-theme=dark] textarea::placeholder{color:#555}[data-theme=dark] .card{background:#252830}[data-theme=dark] header,[data-theme=dark] .sidebar{background:#252830;border-color:#333840}[data-theme=dark] .mobile-nav{background:#252830;border-color:#333840}@media (max-width: 767px){.desktop-only{display:none!important}}@media (min-width: 768px){.mobile-only{display:none!important}}