*,*:before,*:after{margin:0;padding:0;box-sizing:border-box}:root{--bg: #0a0a0a;--bg-raised: #111111;--bg-hover: #1a1a1a;--border: #222222;--text: #ededed;--text-secondary: #888888;--text-tertiary: #555555;--white: #ffffff;--font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;--accent: #3b82f6;--accent-hover: #2563eb;--transition: .2s ease}body{font-family:var(--font);background:var(--bg);color:var(--text);height:100vh;overflow:hidden}#root{height:100vh}.username-screen{display:flex;align-items:center;justify-content:center;height:100vh}.username-card{background:var(--bg-raised);border:1px solid var(--border);border-radius:12px;padding:48px;text-align:center;width:100%;max-width:400px}.username-card h1{font-size:24px;font-weight:700;margin-bottom:8px;color:var(--white)}.username-card p{color:var(--text-secondary);margin-bottom:24px;font-size:14px}.username-card form{display:flex;flex-direction:column;gap:12px}.username-card input{background:var(--bg);border:1px solid var(--border);border-radius:8px;padding:12px 16px;color:var(--text);font-family:var(--font);font-size:14px;outline:none;transition:border-color var(--transition)}.username-card input:focus{border-color:var(--accent)}.username-card button{background:var(--accent);color:var(--white);border:none;border-radius:8px;padding:12px;font-family:var(--font);font-size:14px;font-weight:600;cursor:pointer;transition:background var(--transition)}.username-card button:hover:not(:disabled){background:var(--accent-hover)}.username-card button:disabled{opacity:.4;cursor:not-allowed}.chat-layout{display:flex;height:100vh}.sidebar{width:240px;background:var(--bg-raised);border-right:1px solid var(--border);display:flex;flex-direction:column;overflow-y:auto;flex-shrink:0}.sidebar-section{padding:16px}.sidebar-section h3{font-size:11px;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary);margin-bottom:8px;font-weight:600}.room-list,.user-list{list-style:none}.room-list li{padding:6px 10px;border-radius:6px;cursor:pointer;font-size:14px;color:var(--text-secondary);transition:all var(--transition)}.room-list li:hover{background:var(--bg-hover);color:var(--text)}.room-list li.active{background:var(--bg-hover);color:var(--white);font-weight:500}.create-room{margin-top:8px}.create-room input{width:100%;background:var(--bg);border:1px solid var(--border);border-radius:6px;padding:6px 10px;color:var(--text);font-family:var(--font);font-size:13px;outline:none}.create-room input:focus{border-color:var(--accent)}.user-list li{display:flex;align-items:center;gap:8px;padding:4px 0;font-size:13px;color:var(--text-secondary)}.online-dot{width:8px;height:8px;border-radius:50%;background:#22c55e;flex-shrink:0}.chat-main{flex:1;display:flex;flex-direction:column;min-width:0}.chat-header{padding:14px 20px;border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;flex-shrink:0}.room-name{font-weight:600;font-size:16px;color:var(--white)}.user-badge{font-size:12px;color:var(--text-secondary);background:var(--bg-hover);padding:4px 10px;border-radius:12px}.message-list{flex:1;overflow-y:auto;padding:16px 20px;display:flex;flex-direction:column;gap:4px}.msg{max-width:65%;padding:8px 14px;border-radius:12px;background:var(--bg-raised);border:1px solid var(--border);align-self:flex-start}.msg-own{align-self:flex-end;background:var(--accent);border-color:var(--accent)}.msg-own .msg-meta .msg-user,.msg-own .msg-meta .msg-time{color:#ffffffb3}.msg-own .msg-body{color:var(--white)}.msg-meta{display:flex;gap:8px;align-items:baseline;margin-bottom:2px}.msg-user{font-size:12px;font-weight:600;color:var(--accent)}.msg-own .msg-user{color:#ffffffb3}.msg-time{font-size:11px;color:var(--text-tertiary)}.msg-body{font-size:14px;line-height:1.4;word-break:break-word}.msg-system{text-align:center;font-size:12px;color:var(--text-tertiary);padding:4px 0}.msg-image{max-width:300px;max-height:300px;border-radius:8px;display:block;margin-top:4px}.msg-file-link{color:var(--accent);text-decoration:underline}.msg-own .msg-file-link{color:var(--white)}.typing-indicator{height:20px;padding:0 20px;font-size:12px;color:var(--text-tertiary);flex-shrink:0;display:flex;align-items:center}.message-input{display:flex;align-items:center;gap:8px;padding:12px 16px;border-top:1px solid var(--border);flex-shrink:0}.message-input input[type=text]{flex:1;background:var(--bg-raised);border:1px solid var(--border);border-radius:8px;padding:10px 14px;color:var(--text);font-family:var(--font);font-size:14px;outline:none;transition:border-color var(--transition)}.message-input input[type=text]:focus{border-color:var(--accent)}.message-input button{background:var(--accent);color:var(--white);border:none;border-radius:8px;padding:10px 16px;font-family:var(--font);font-size:14px;font-weight:500;cursor:pointer;transition:background var(--transition);flex-shrink:0}.message-input button:hover:not(:disabled){background:var(--accent-hover)}.message-input button:disabled{opacity:.4;cursor:not-allowed}.file-btn{width:38px;height:38px;padding:0!important;display:flex;align-items:center;justify-content:center;font-size:20px;font-weight:300;background:var(--bg-raised)!important;border:1px solid var(--border)!important;color:var(--text-secondary)!important}.file-btn:hover{border-color:var(--accent)!important;color:var(--text)!important}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px}::-webkit-scrollbar-thumb:hover{background:var(--text-tertiary)}@media (max-width: 640px){.sidebar{width:180px}.msg{max-width:85%}.username-card{margin:16px;padding:32px 24px}}