:root{--primary-color:#ff477e;--primary-hover:#e03e6f;--bg-main:#f0f2f5;--bg-app:#fff;--bg-sidebar:#f8f9fa;--text-main:#1d1e2c;--text-muted:#757a86;--border-color:#e5e7eb;--danger:#ef233c;--success:#10b981;--bubble-sent:#ff477e;--bubble-received:#f1f2f6;--shadow-sm:0 2px 8px #0000000a;--shadow-lg:0 20px 40px #00000014;--radius-lg:24px;--radius-md:16px;--radius-sm:12px}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-main);color:var(--text-main);justify-content:center;align-items:center;height:100vh;font-family:Inter,-apple-system,sans-serif;display:flex;overflow:hidden}#app{background:var(--bg-main);width:100%;max-width:1300px;height:100%;position:relative}@media (width>=768px){#app{border-radius:var(--radius-lg);height:92vh;max-height:900px;box-shadow:var(--shadow-lg);background:var(--bg-app);overflow:hidden}}.screen{justify-content:center;align-items:center;width:100%;height:100%;transition:opacity .4s,visibility .4s;display:flex;position:absolute;top:0;left:0}.hidden{opacity:0;visibility:hidden;pointer-events:none}#toast-container{z-index:1000;flex-direction:column;gap:12px;display:flex;position:fixed;top:24px;right:24px}.toast{color:var(--text-main);border-radius:var(--radius-md);box-shadow:var(--shadow-lg);background:#fff;align-items:center;gap:12px;padding:1rem 1.5rem;font-size:.95rem;font-weight:600;animation:.3s cubic-bezier(.175,.885,.32,1.275) forwards slideIn;display:flex}.toast.success{border-left:6px solid var(--success)}.toast.error{border-left:6px solid var(--danger)}@keyframes slideIn{0%{opacity:0;transform:translate(100%)}to{opacity:1;transform:translate(0)}}@keyframes slideOut{0%{opacity:1;transform:translate(0)}to{opacity:0;transform:translate(120%)}}#auth-screen{background:var(--bg-main)}.card{border-radius:var(--radius-lg);text-align:center;width:100%;max-width:420px;box-shadow:var(--shadow-lg);background:#fff;padding:3.5rem 3rem}.auth-icon{justify-content:center;margin-bottom:1.5rem;display:flex}.card h1{letter-spacing:-.5px;color:var(--text-main);margin-bottom:.5rem;font-size:2rem;font-weight:800}.subtitle{color:var(--text-muted);margin-bottom:2.5rem;font-size:1rem;font-weight:500}form{flex-direction:column;gap:1.2rem;display:flex}input{border-radius:var(--radius-md);border:2px solid var(--border-color);width:100%;color:var(--text-main);background:#fafafa;outline:none;padding:1rem 1.2rem;font-size:1rem;font-weight:500;transition:all .2s}input:focus{border-color:var(--primary-color);background:#fff;box-shadow:0 0 0 4px #ff477e1a}button[type=submit],#auth-submit{background:var(--primary-color);color:#fff;border-radius:var(--radius-md);cursor:pointer;border:none;padding:1.1rem;font-size:1.05rem;font-weight:700;transition:all .2s;box-shadow:0 8px 16px #ff477e40}button[type=submit]:hover,#auth-submit:hover{background:var(--primary-hover);transform:translateY(-2px);box-shadow:0 12px 20px #ff477e4d}button[type=submit]:active,#auth-submit:active{transform:translateY(1px);box-shadow:0 4px 8px #ff477e33}.divider{text-align:center;color:var(--text-muted);align-items:center;margin:1.8rem 0;font-size:.85rem;font-weight:600;display:flex}.divider:before,.divider:after{content:"";border-bottom:2px solid var(--border-color);flex:1}.divider span{padding:0 12px}.google-login-wrapper{justify-content:center;width:100%;margin-bottom:1.5rem;display:flex}.toggle-auth{color:var(--text-muted);margin-top:1.5rem;font-size:.95rem;font-weight:500}.toggle-auth a{color:var(--primary-color);margin-left:.3rem;font-weight:700;text-decoration:none}.error-msg{color:var(--danger);min-height:20px;margin-top:1rem;font-size:.9rem;font-weight:600}#chat-screen{background:var(--bg-app);align-items:stretch;gap:1.5rem;padding:1.5rem}.sidebar{border-radius:var(--radius-lg);background:var(--bg-sidebar);border:1px solid var(--border-color);flex-direction:column;width:340px;display:flex;overflow:hidden}.sidebar-header{flex-direction:column;gap:1rem;padding:1.5rem 1.5rem 1rem;display:flex}.sidebar-header h2{letter-spacing:-.5px;color:var(--text-main);font-size:1.4rem;font-weight:800}.user-profile{justify-content:space-between;align-items:center;width:100%;display:flex}.profile-actions{gap:.5rem;display:flex}.current-user-badge{color:var(--primary-color);border-radius:var(--radius-sm);background:#ff477e1a;padding:.4rem .8rem;font-size:.85rem;font-weight:700}.icon-btn{border:1px solid var(--border-color);width:38px;height:38px;color:var(--text-muted);box-shadow:var(--shadow-sm);cursor:pointer;background:#fff;border-radius:50%;justify-content:center;align-items:center;padding:0;transition:all .2s;display:flex}.icon-btn i{width:18px;height:18px}.icon-btn:hover{background:var(--primary-color);border-color:var(--primary-color);color:#fff;transform:translateY(-2px);box-shadow:0 4px 10px #ff477e33}.search-bar{gap:.5rem;padding:0 1.5rem 1rem;display:flex}.search-bar input{border-radius:var(--radius-md);border:1px solid var(--border-color);background:#fff;padding:.8rem 1.2rem;font-size:.95rem}.search-bar button{border-radius:var(--radius-md);box-shadow:none;padding:0 1.2rem;font-size:.95rem}#user-list{flex:1;padding:0 1rem 1rem;list-style:none;overflow-y:auto}.user-item{cursor:pointer;border-radius:var(--radius-md);border:1px solid #0000;align-items:center;gap:1rem;margin-bottom:.3rem;padding:.8rem 1rem;transition:all .2s;display:flex}.user-item:hover{border-color:var(--border-color);box-shadow:var(--shadow-sm);background:#fff}.user-item.active{border-color:var(--primary-color);background:#fff;box-shadow:0 4px 12px #ff477e1a}.user-item.active .user-name{color:var(--primary-color);font-weight:700}.avatar{color:#fff;object-fit:cover;width:46px;height:46px;box-shadow:var(--shadow-sm);background:linear-gradient(135deg,#a88bec,#fbc2eb);border:2px solid #fff;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:1.2rem;font-weight:700;display:flex}.user-info{flex:1}.user-name{font-size:1.05rem;font-weight:600}.status-dot{background:#d1d5db;border:2px solid #fff;border-radius:50%;width:12px;height:12px}.status-dot.online{background:var(--success)}.main-chat{border-radius:var(--radius-lg);border:1px solid var(--border-color);background:#fff;flex-direction:column;flex:1;display:flex;overflow:hidden}.chat-header{border-bottom:1px solid var(--border-color);z-index:10;background:#fff;align-items:center;padding:1.2rem 2rem;display:flex}.chat-header-info{align-items:center;gap:1rem;display:flex}#chat-header-name{font-size:1.2rem;font-weight:700}.chat-messages{background:#fafafa;flex-direction:column;flex:1;gap:.8rem;padding:2rem;display:flex;overflow-y:auto}.empty-state{color:var(--text-muted);text-align:center;flex-direction:column;align-items:center;margin:auto;font-size:1.1rem;font-weight:500;display:flex}.empty-icon{color:var(--border-color);margin-bottom:1rem}.message{max-width:65%;box-shadow:var(--shadow-sm);padding:.9rem 1.2rem;font-size:.95rem;font-weight:500;line-height:1.5;animation:.3s cubic-bezier(.175,.885,.32,1.275) popIn;position:relative}.message.sent{background:var(--bubble-sent);color:#fff;border-radius:20px 20px 4px;align-self:flex-end}.message.received{color:var(--text-main);border:1px solid var(--border-color);background:#fff;border-radius:20px 20px 20px 4px;align-self:flex-start}.message-time{opacity:.7;text-align:right;margin-top:.4rem;font-size:.7rem;display:block}.chat-input-area{border-top:1px solid var(--border-color);background:#fff;padding:1.2rem 2rem}#chat-form{flex-direction:row;align-items:center;gap:1rem;width:100%;display:flex}.attach-btn{background:var(--bg-sidebar);border:1px solid var(--border-color);width:48px;height:48px;color:var(--text-muted);box-shadow:none;cursor:pointer;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;padding:0;font-size:1.2rem;transition:all .2s;display:flex}.attach-btn i{width:20px;height:20px}.attach-btn:hover{color:var(--text-main);background:#e5e7eb}#file-input{display:none}#message-input{background:var(--bg-sidebar);border:1px solid var(--border-color);width:100%;min-width:0;color:var(--text-main);border-radius:24px;outline:none;flex:auto;padding:1.1rem 1.5rem;font-size:.95rem}#message-input:focus{border:1px solid var(--primary-color);background:#fff;box-shadow:0 0 0 4px #ff477e1a}.send-btn{background:var(--primary-color);cursor:pointer;border:none;border-radius:50%;justify-content:center;align-items:center;width:48px;height:48px;padding:0;transition:all .2s;display:flex;box-shadow:0 4px 12px #ff477e4d}.send-btn:hover{background:var(--primary-hover);transform:translateY(-2px);box-shadow:0 6px 16px #ff477e66}.send-btn:active{transform:translateY(1px)}.message-image{border-radius:12px;max-width:100%;margin-bottom:.5rem;display:block}.message-file{color:inherit;background:#0000000d;border-radius:12px;align-items:center;gap:.8rem;margin-bottom:.5rem;padding:.8rem 1.2rem;font-weight:600;text-decoration:none;transition:background .2s;display:flex}.message.received .message-file{background:var(--bg-sidebar)}.message-file:hover{background:#0000001a;text-decoration:underline}.message-file-icon{width:24px;height:24px}@keyframes popIn{0%{opacity:0;transform:translateY(10px)scale(.95)}to{opacity:1;transform:translateY(0)scale(1)}}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:0 0}::-webkit-scrollbar-thumb{background:#cbd5e1;border-radius:10px}::-webkit-scrollbar-thumb:hover{background:#94a3b8}.modal-overlay{-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);z-index:2000;background:#0006;justify-content:center;align-items:center;width:100vw;height:100vh;transition:opacity .3s,visibility .3s;display:flex;position:fixed;top:0;left:0}.settings-modal{background:var(--bg-app);border-radius:var(--radius-lg);width:90%;max-width:480px;box-shadow:var(--shadow-lg);flex-direction:column;transition:transform .3s cubic-bezier(.175,.885,.32,1.275);display:flex;overflow:hidden;transform:scale(.95)}.modal-overlay:not(.hidden) .settings-modal{transform:scale(1)}.modal-header{border-bottom:1px solid var(--border-color);justify-content:space-between;align-items:center;padding:1.5rem 2rem;display:flex}.modal-header h3{color:var(--text-main);font-size:1.4rem;font-weight:800}.modal-body{max-height:80vh;padding:2rem;overflow-y:auto}.avatar-upload-container{cursor:pointer;width:100px;height:100px;box-shadow:var(--shadow-sm);border:4px solid #fff;border-radius:50%;margin:0 auto 2rem;position:relative;overflow:hidden}.avatar-large{object-fit:cover;color:#fff;background:linear-gradient(135deg,#a88bec,#fbc2eb);justify-content:center;align-items:center;width:100%;height:100%;font-size:2.5rem;font-weight:700;display:flex}.avatar-upload-overlay{opacity:0;background:#00000080;justify-content:center;align-items:center;width:100%;height:100%;transition:opacity .2s;display:flex;position:absolute;top:0;left:0}.avatar-upload-container:hover .avatar-upload-overlay{opacity:1}.form-group{margin-bottom:1.5rem}.form-group label{color:var(--text-main);margin-bottom:.5rem;font-size:.9rem;font-weight:700;display:block}.form-group input{background:var(--bg-main)}.form-group input:read-only{background:var(--bg-sidebar);color:var(--text-muted);cursor:not-allowed}.stats-box{background:var(--bg-sidebar);border-radius:var(--radius-md);gap:1rem;margin-bottom:2rem;padding:1rem;display:flex}.stat{text-align:center;flex:1}.stat-value{color:var(--primary-color);font-size:1.5rem;font-weight:800;display:block}.stat-label{color:var(--text-muted);text-transform:uppercase;letter-spacing:.5px;font-size:.85rem;font-weight:600}.w-100{width:100%}.primary-btn{background:var(--primary-color);color:#fff;border-radius:var(--radius-md);cursor:pointer;border:none;padding:1.1rem;font-size:1.05rem;font-weight:700;transition:all .2s;box-shadow:0 8px 16px #ff477e40}.primary-btn:hover{background:var(--primary-hover);transform:translateY(-2px);box-shadow:0 12px 20px #ff477e4d}.primary-btn:active{transform:translateY(1px);box-shadow:0 4px 8px #ff477e33}