:root{font-family:Inter,system-ui,Avenir,Helvetica,Arial,sans-serif;line-height:1.5;font-weight:400;color-scheme:light dark;color:#ffffffde;background-color:#242424}body{margin:0;display:flex;place-items:center;min-width:320px;min-height:100vh;background-color:#f0f2f5;color:#333}#app{width:100%;max-width:1280px;margin:0 auto;padding:0;text-align:center}.chat-container{width:100%;max-width:800px;margin:20px auto;border:1px solid #e0e0e0;border-radius:16px;height:90vh;display:flex;flex-direction:column;background-color:#fff;box-shadow:0 4px 20px #00000014;overflow:hidden}header{padding:15px;background-color:#fff;border-bottom:1px solid #f0f0f0;display:flex;flex-direction:column;gap:10px;align-items:center}header h1{margin:0;font-size:1.2rem;font-weight:700;color:#333}.model-switcher{display:flex;gap:8px;background-color:#f0f2f5;padding:4px;border-radius:8px}.model-btn{padding:6px 12px;border:none;background:transparent;cursor:pointer;border-radius:6px;font-size:13px;color:#666;font-weight:500;transition:all .2s}.model-btn:hover{background-color:#0000000d}.model-btn.active{background-color:#fff;color:#333;box-shadow:0 1px 3px #0000001a;font-weight:600}.messages{flex:1;padding:20px;overflow-y:auto;display:flex;flex-direction:column;gap:20px;background-color:#f8f9fa}.message{display:flex;width:100%;gap:10px;align-items:flex-start}.avatar{width:36px;height:36px;border-radius:50%;background-color:#e0e0e0;display:flex;align-items:center;justify-content:center;font-size:20px;flex-shrink:0}.bubble{padding:12px 18px;border-radius:18px;max-width:70%;word-wrap:break-word;text-align:left;font-size:15px;line-height:1.6;position:relative;box-shadow:0 1px 2px #0000000d}.message.user{flex-direction:row-reverse}.message.user .bubble{background-color:#95ec69;color:#000;border-top-right-radius:4px}.message.user .avatar{background-color:#95ec69}.message.assistant{justify-content:flex-start}.message.assistant .bubble{background-color:#fff;color:#333;border:1px solid #e0e0e0;border-top-left-radius:4px}.message.assistant .avatar{background-color:#fff;border:1px solid #eee}.loading{font-style:italic;color:#888}.input-area{padding:20px;border-top:1px solid #eee;display:flex;gap:12px;background-color:#fff}.input-area input{flex:1;padding:14px;border:1px solid #ddd;border-radius:24px;outline:none;font-size:16px;transition:border-color .2s;background-color:#f8f9fa}.input-area input:focus{border-color:#95ec69;background-color:#fff}.input-area button{padding:0 28px;background-color:#95ec69;color:#000;border:none;border-radius:24px;cursor:pointer;font-weight:600;font-size:15px;transition:all .2s}.input-area button:disabled{background-color:#e0e0e0;color:#999;cursor:not-allowed}.input-area button:hover:not(:disabled){opacity:.9;transform:translateY(-1px)}