:root{--bg-color: #f7f8fc;--text-color: #333;--user-bubble-bg: #0084ff;--bot-bubble-bg: #e5e5ea;--input-bg: #ffffff;--input-border: #ccc;--send-btn-bg: #0084ff;--send-btn-hover: #006fd6}.dark-mode{--bg-color: #1e1e2f;--text-color: #f1f1f1;--user-bubble-bg: #007bff;--bot-bubble-bg: #2f2f40;--input-bg: #2a2a3a;--input-border: #444;--send-btn-bg: #007bff;--send-btn-hover: #005bb5}.chat-wrapper{display:flex;flex-direction:column;height:97vh;background-color:var(--bg-color);color:var(--text-color);font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;transition:background-color .3s,color .3s;border-radius:10px}@media (max-width: 768px){.chat-wrapper{height:100vh}.dark-mode-toggle{display:none}.message-video{width:250px!important}}.chat-header{padding:10px 16px;text-align:right;background-color:transparent}.chat-header button{background:none;border:1px solid var(--input-border);border-radius:20px;padding:6px 12px;color:var(--text-color);cursor:pointer}.chat-window{flex:1;padding:20px;overflow-y:auto;display:flex;flex-direction:column}.welcome-message{font-size:1.2em;color:var(--text-color);text-align:center;margin-top:20px;font-weight:700}.welcome-message.welhead{font-size:2em;color:var(--text-color);text-align:center;margin-top:20px;font-weight:700}.message-row{display:flex;margin-bottom:10px}.message-row.user{justify-content:flex-end}.message-row.bot{justify-content:flex-start}.message-bubble{max-width:70%;padding:12px 16px;border-radius:16px;font-size:15px;line-height:1.4;word-wrap:break-word;white-space:pre-wrap;transition:background-color .3s,color .3s}.message-row.user .message-bubble{background-color:var(--user-bubble-bg);color:#fff;border-bottom-right-radius:0}.message-row.bot .message-bubble{background-color:var(--bot-bubble-bg);color:var(--text-color);border-bottom-left-radius:0}.message-text{white-space:pre-wrap}.message-video{width:300px}.typing{display:flex;align-items:center}.typing .dots{display:inline-flex;gap:4px;margin-left:8px}.typing .dots span{width:6px;height:6px;background-color:var(--text-color);border-radius:50%;animation:bounce 1.4s infinite}.typing .dots span:nth-child(2){animation-delay:.2s}.typing .dots span:nth-child(3){animation-delay:.4s}@keyframes bounce{0%,80%,to{transform:scale(.6);opacity:.3}40%{transform:scale(1);opacity:1}}.uploaded-image{max-width:120px;max-height:120px;border-radius:8px;margin-top:5px;object-fit:contain}.document-bubble{background-color:#f5f5f5;padding:10px 14px;border-radius:8px;margin-top:6px;font-size:14px;color:#333;max-width:90%;word-wrap:break-word;border:1px solid #ddd}.file-type{font-size:12px;color:#666}.image-preview{display:flex;align-items:center;padding:10px 16px;gap:10px;background-color:var(--input-bg);border-top:1px solid var(--input-border);border-bottom:1px solid var(--input-border)}.image-preview img{max-height:60px;border-radius:6px;object-fit:contain}.image-preview button{background:none;border:none;color:red;font-size:18px;cursor:pointer}.document-preview{padding:6px 10px;border-radius:8px;background:#eee;color:#333;font-size:14px;margin-top:5px}.chat-input-area{display:flex;align-items:center;padding:12px 16px;border-top:1px solid var(--input-border);background-color:var(--input-bg)}.chat-input-area input[type=text]{flex:1;padding:10px 14px;border-radius:20px;border:1px solid var(--input-border);font-size:15px;outline:none;margin-right:10px;background-color:var(--input-bg);color:var(--text-color)}.upload-label{font-size:20px;cursor:pointer;margin-right:10px}.chat-input-area button{padding:10px 14px;border:none;border-radius:20px;background-color:var(--send-btn-bg);color:#fff;cursor:pointer;font-size:16px;transition:background-color .3s ease}.chat-input-area button:hover{background-color:var(--send-btn-hover)}.file-preview{display:flex;flex-wrap:wrap;gap:10px;margin-top:10px;padding:10px;background-color:var(--input-bg)}