:root{--bg-page: #f3f2f1;--accent-blue: #0078d4;--excel-green: #217346;--card-bg: #ffffff;--card-shadow: 0 2px 8px rgba(0, 0, 0, .08);--text-primary: #323130;--text-secondary: #605e5c;--border-color: #edebe9;--error-red: #d13438}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Segoe UI,-apple-system,BlinkMacSystemFont,sans-serif;background:var(--bg-page);color:var(--text-primary);line-height:1.5}.landing-page{min-height:100vh;display:flex;flex-direction:column}.header{display:flex;align-items:center;justify-content:space-between;padding:16px 32px;background:var(--card-bg);border-bottom:1px solid var(--border-color);box-shadow:var(--card-shadow);position:sticky;top:0;z-index:100}.header-logo{display:flex;align-items:center;gap:12px;font-size:20px;font-weight:700;color:var(--accent-blue)}.header-logo svg{width:32px;height:32px}.main-content{display:flex;flex:1;gap:0}.left-panel{flex:0 0 60%;padding:40px 48px;overflow-y:auto}.left-panel h1{font-size:32px;font-weight:700;color:var(--text-primary);margin-bottom:8px}.left-panel .subtitle{font-size:16px;color:var(--text-secondary);margin-bottom:40px}.section{margin-bottom:40px}.section h2{font-size:20px;font-weight:600;margin-bottom:16px;color:var(--text-primary)}.steps-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.step-card{background:var(--card-bg);border:1px solid var(--border-color);border-radius:8px;padding:24px 20px;box-shadow:var(--card-shadow)}.step-number{display:inline-flex;align-items:center;justify-content:center;width:36px;height:36px;border-radius:50%;background:var(--accent-blue);color:#fff;font-weight:700;font-size:16px;margin-bottom:12px}.step-card h3{font-size:15px;font-weight:600;margin-bottom:6px}.step-card p{font-size:13px;color:var(--text-secondary)}.example-commands{display:flex;flex-direction:column;gap:10px}.example-command{background:var(--card-bg);border:1px solid var(--border-color);border-radius:8px;padding:12px 16px;font-size:14px;display:flex;align-items:center;gap:10px}.example-command .arrow{color:var(--accent-blue);font-weight:700}.advantages-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}.advantage-card{background:var(--card-bg);border:1px solid var(--border-color);border-radius:8px;padding:20px;box-shadow:var(--card-shadow)}.advantage-card h3{font-size:15px;font-weight:600;margin-bottom:4px}.advantage-card p{font-size:13px;color:var(--text-secondary)}.right-panel{flex:0 0 40%;display:flex;flex-direction:column;border-left:1px solid var(--border-color);background:var(--card-bg);height:calc(100vh - 65px);position:sticky;top:65px}.chat-container{flex:1;overflow-y:auto;padding:20px;display:flex;flex-direction:column;gap:16px}.chat-input-bar{display:flex;gap:8px;padding:16px 20px;border-top:1px solid var(--border-color)}.chat-input-bar input{flex:1;padding:10px 16px;border:1px solid var(--border-color);border-radius:6px;font-size:14px;outline:none;transition:border-color .2s}.chat-input-bar input:focus{border-color:var(--accent-blue)}.chat-input-bar button{padding:10px 20px;background:var(--accent-blue);color:#fff;border:none;border-radius:6px;font-size:14px;font-weight:600;cursor:pointer;transition:background .2s}.chat-input-bar button:hover{background:#006cbd}.chat-input-bar button:disabled{background:#c8c6c4;cursor:not-allowed}.chat-message{display:flex;gap:10px;animation:fadeIn .3s ease}@keyframes fadeIn{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.chat-message.bot{align-self:flex-start}.chat-message.user{align-self:flex-end;flex-direction:row-reverse}.message-avatar{width:32px;height:32px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:14px;flex-shrink:0}.bot .message-avatar{background:var(--excel-green);color:#fff}.user .message-avatar{background:var(--accent-blue);color:#fff}.message-bubble{max-width:320px;padding:12px 16px;border-radius:12px;font-size:14px;line-height:1.5;white-space:pre-wrap}.bot .message-bubble{background:#f3f2f1;border-bottom-left-radius:4px}.user .message-bubble{background:var(--accent-blue);color:#fff;border-bottom-right-radius:4px}.file-upload-zone{--angle: 0deg;border:2px solid transparent;border-radius:12px;padding:32px 20px;text-align:center;cursor:pointer;transition:all .2s;background:linear-gradient(var(--bg-page),var(--bg-page)) padding-box,conic-gradient(from var(--angle),#0078d4,#217346,#0078d4,#217346,#0078d4) border-box;animation:rotate-border 3s linear infinite;position:relative}@keyframes rotate-border{to{--angle: 360deg}}@property --angle{syntax: "<angle>"; initial-value: 0deg; inherits: false;}.file-upload-zone:hover,.file-upload-zone.dragover{background:linear-gradient(#eff6fc,#eff6fc) padding-box,conic-gradient(from var(--angle),#0078d4,#217346,#0078d4,#217346,#0078d4) border-box}.file-upload-zone .icon{font-size:36px;margin-bottom:8px}.file-upload-zone p{font-size:14px;color:var(--text-secondary)}.file-upload-zone .hint{font-size:12px;color:var(--text-secondary);margin-top:4px}.provider-select{display:flex;gap:6px}.provider-btn{padding:6px 12px;border:1px solid var(--border-color);border-radius:4px;background:var(--card-bg);font-size:12px;cursor:pointer;transition:all .2s;color:var(--text-secondary)}.provider-btn.active{background:var(--accent-blue);color:#fff;border-color:var(--accent-blue)}.provider-btn:hover:not(.active){border-color:var(--accent-blue);color:var(--accent-blue)}.table-preview{margin:12px 0;border:1px solid var(--border-color);border-radius:8px;overflow:hidden;max-height:260px;overflow-y:auto}.table-preview table{width:100%;border-collapse:collapse;font-size:12px}.table-preview th{background:#f3f2f1;padding:8px 10px;text-align:left;font-weight:600;border-bottom:1px solid var(--border-color);position:sticky;top:0}.table-preview td{padding:6px 10px;border-bottom:1px solid var(--border-color);max-width:160px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.confirm-buttons{display:flex;gap:8px;margin-top:8px}.confirm-btn{padding:8px 16px;border:none;border-radius:6px;font-size:13px;font-weight:600;cursor:pointer}.confirm-btn.yes{background:var(--excel-green);color:#fff}.confirm-btn.no{background:var(--border-color);color:var(--text-secondary)}.download-btn{display:inline-flex;align-items:center;gap:6px;margin-top:8px;padding:8px 16px;background:var(--accent-blue);color:#fff;border:none;border-radius:6px;font-size:13px;font-weight:600;cursor:pointer;text-decoration:none}.download-btn:hover{background:#006cbd}.spinner{display:inline-block;width:16px;height:16px;border:2px solid var(--border-color);border-top-color:var(--accent-blue);border-radius:50%;animation:spin .8s linear infinite;margin-right:8px;vertical-align:middle}@keyframes spin{to{transform:rotate(360deg)}}.footer{display:flex;align-items:center;justify-content:center;padding:16px 32px;background:var(--card-bg);border-top:1px solid var(--border-color);font-size:13px;color:var(--text-secondary);gap:8px}.footer a{color:var(--accent-blue);text-decoration:none}.footer a:hover{text-decoration:underline}.error-message{color:var(--error-red);font-size:13px;margin-top:4px}@media(max-width:900px){.main-content{flex-direction:column}.left-panel{flex:none;padding:24px 20px}.right-panel{flex:none;border-left:none;border-top:1px solid var(--border-color);height:70vh;position:static}.steps-grid,.advantages-grid{grid-template-columns:1fr}.header{padding:12px 16px}.provider-select{display:none}}