.chat-layout{display:flex;height:calc(100vh - 64px);margin-top:64px}.chat-sidebar{width:260px;background:var(--bg-secondary);border-right:1px solid var(--border);display:flex;flex-direction:column;transition:width .2s}.chat-sidebar.collapsed{width:0;overflow:hidden}.sidebar-header{padding:16px}.new-chat-btn{width:100%}.session-list{flex:1;overflow-y:auto;padding:0 8px}.session-item{display:flex;align-items:center;justify-content:space-between;padding:10px 12px;border-radius:8px;cursor:pointer;font-size:14px;color:var(--text-secondary);margin-bottom:4px}.session-item:hover,.session-item.active{background:#818cf81a;color:var(--text-primary)}.del-btn{background:none;border:none;color:var(--text-muted);cursor:pointer;font-size:16px;opacity:0}.session-item:hover .del-btn{opacity:1}.sidebar-footer{padding:16px;border-top:1px solid var(--border);display:flex;justify-content:space-between;align-items:center;font-size:14px}.sidebar-footer button{background:none;border:none;color:var(--accent-primary);cursor:pointer}.chat-main{flex:1;display:flex;flex-direction:column;position:relative}.sidebar-toggle{display:none;position:absolute;top:12px;left:12px;background:var(--bg-elevated);border:1px solid var(--border);color:var(--text-primary);padding:6px 10px;border-radius:6px;cursor:pointer;z-index:10}.messages{flex:1;overflow-y:auto;padding:24px;display:flex;flex-direction:column;gap:16px}.empty-chat{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;color:var(--text-secondary)}.empty-chat h2{font-size:28px;margin-bottom:8px}.message{display:flex}.message.user{justify-content:flex-end}.message.assistant{justify-content:flex-start}.message-bubble{max-width:70%;padding:12px 16px;border-radius:12px;font-size:15px;line-height:1.6}.message.user .message-bubble{background:linear-gradient(135deg,#818cf8,#6366f1);color:#fff;border-bottom-right-radius:4px}.message.assistant .message-bubble{background:var(--bg-elevated);border:1px solid var(--border);border-bottom-left-radius:4px}.msg-image,.msg-ref-image{max-width:100%;border-radius:8px;margin-bottom:8px}.typing{color:var(--text-muted);font-style:italic}.input-area{padding:16px 24px 24px;border-top:1px solid var(--border)}.mode-tabs{display:flex;gap:8px;margin-bottom:12px}.mode-tabs button{padding:6px 16px;background:transparent;border:1px solid var(--border);border-radius:20px;color:var(--text-secondary);cursor:pointer;font-size:13px}.mode-tabs button.active{background:#818cf826;border-color:var(--accent-primary);color:var(--accent-primary)}.image-preview{position:relative;display:inline-block;margin-bottom:8px}.image-preview img{height:60px;border-radius:8px}.image-preview button{position:absolute;top:-6px;right:-6px;background:#ef4444;color:#fff;border:none;border-radius:50%;width:20px;height:20px;cursor:pointer;font-size:12px}.input-row{display:flex;align-items:flex-end;gap:8px;background:var(--bg-elevated);border:1px solid var(--border);border-radius:12px;padding:8px 12px}.input-row textarea{flex:1;border:none;background:transparent;resize:none;max-height:120px;padding:8px}.upload-btn{cursor:pointer;font-size:20px;padding:4px}.send-btn{padding:8px 20px}.chat-landing{height:calc(100vh - 64px);margin-top:64px;display:flex;align-items:center;justify-content:center}.chat-landing-inner{text-align:center}.chat-landing-inner h1{font-size:48px;margin-bottom:16px}.chat-landing-inner p{color:var(--text-secondary);margin-bottom:32px}@media(max-width:768px){.sidebar-toggle{display:block}.message-bubble{max-width:90%}}.auth-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#000000b3;display:flex;align-items:center;justify-content:center;z-index:2000}.auth-modal{width:100%;max-width:400px;display:flex;flex-direction:column;gap:12px}.auth-modal h2{text-align:center;margin-bottom:8px}.auth-error{color:#f87171;font-size:14px;text-align:center}.code-row{display:flex;gap:8px}.code-row input{flex:1}.code-row button{white-space:nowrap;font-size:13px;padding:8px 12px}.auth-submit{margin-top:8px;width:100%}.auth-links{display:flex;justify-content:space-between;margin-top:8px}.auth-links button{background:none;border:none;color:var(--accent-primary);cursor:pointer;font-size:14px}:root{--bg-primary: #0a0e17;--bg-secondary: #111827;--bg-elevated: #1a2332;--accent-primary: #818cf8;--accent-secondary: #6366f1;--text-primary: #f1f5f9;--text-secondary: #94a3b8;--text-muted: #64748b;--border: rgba(129, 140, 248, .15);--glass: rgba(17, 24, 39, .7)}*{box-sizing:border-box;margin:0;padding:0}body{font-family:Inter,PingFang SC,Microsoft YaHei,sans-serif;background:var(--bg-primary);color:var(--text-primary);line-height:1.6}a{color:var(--accent-primary);text-decoration:none}.container{max-width:1200px;margin:0 auto;padding:0 24px}.gradient-text{background:linear-gradient(135deg,#818cf8,#6366f1);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.btn-primary{padding:10px 24px;background:linear-gradient(135deg,#818cf8,#6366f1);color:#fff;border:none;border-radius:8px;font-size:15px;font-weight:600;cursor:pointer}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.btn-outline{padding:10px 24px;background:transparent;color:var(--accent-primary);border:1px solid var(--accent-primary);border-radius:8px;cursor:pointer}input,textarea{width:100%;padding:12px 16px;background:var(--bg-elevated);border:1px solid var(--border);border-radius:8px;color:var(--text-primary);font-size:15px;outline:none}input:focus,textarea:focus{border-color:var(--accent-primary)}.card{background:var(--bg-secondary);border:1px solid var(--border);border-radius:12px;padding:24px}.section{padding:80px 0}.site-header{position:fixed;top:0;left:0;right:0;height:64px;background:var(--glass);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);border-bottom:1px solid var(--border);z-index:1000}.header-inner{display:flex;align-items:center;justify-content:space-between;height:64px}.logo{font-size:18px;font-weight:700;color:inherit}.nav{display:flex;gap:4px}.nav a{color:var(--text-secondary);padding:8px 14px;border-radius:6px;font-size:14px}.nav a:hover{color:var(--accent-primary);background:#818cf814}.nav-chat{color:var(--accent-primary)!important}.hero-section{min-height:100vh;display:flex;align-items:center;padding-top:64px;background:radial-gradient(ellipse at 50% 0%,rgba(129,140,248,.12) 0%,transparent 60%)}.hero-inner{text-align:center;padding:80px 0}.hero-inner h1{font-size:clamp(36px,5vw,56px);margin-bottom:16px}.hero-inner p{color:var(--text-secondary);font-size:18px;margin-bottom:32px}.page-content{padding-top:120px;min-height:60vh}.page-content h1{font-size:36px}.features-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:20px;margin-top:32px}.features-grid h3{margin-bottom:8px}.features-grid p{color:var(--text-secondary);font-size:14px}.site-footer{background:var(--bg-secondary);border-top:1px solid var(--border);padding:24px 0;text-align:center}.footer-inner p{color:var(--text-muted);font-size:13px;margin-bottom:4px}@media(max-width:768px){.nav{display:none}}