:root{--nike-black: #111;--nike-grey: #757575;--accent: #4f46e5;--accent-dark: #3730a3;--bg: #f5f5f7;--bot: #eef0f5;--customer: #d7f3dd;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--nike-black)}.app{min-height:100vh;display:flex;flex-direction:column;align-items:center}.topbar{width:100%;padding:18px 28px;background:var(--nike-black);color:#fff;font-weight:800;font-size:20px;letter-spacing:.5px}.container{width:100%;max-width:760px;padding:32px 20px}.hero h1{font-size:28px;margin:0 0 6px}.hero p{color:var(--nike-grey);margin:0 0 28px}.choice-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}@media (max-width: 560px){.choice-grid{grid-template-columns:1fr}}.choice-card{background:#fff;border:1px solid #e5e7eb;border-radius:16px;padding:28px 24px;cursor:pointer;text-align:left;transition:transform .12s ease,box-shadow .12s ease,border-color .12s;font:inherit;color:inherit}.choice-card:hover{transform:translateY(-2px);box-shadow:0 8px 24px #00000014;border-color:var(--accent)}.choice-card .icon{font-size:34px}.choice-card h3{margin:12px 0 4px;font-size:18px}.choice-card p{margin:0;color:var(--nike-grey);font-size:14px}.back-btn{background:none;border:none;color:var(--accent);font:inherit;cursor:pointer;padding:0;margin-bottom:16px}.chat{background:#fff;border:1px solid #e5e7eb;border-radius:16px;overflow:hidden;display:flex;flex-direction:column;height:560px}.chat-header{background:var(--nike-black);color:#fff;padding:14px 18px;font-weight:700}.chat-body{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:10px}.msg{max-width:78%;padding:10px 14px;border-radius:14px;font-size:14px;line-height:1.4}.msg.bot{background:var(--bot);align-self:flex-start;border-bottom-left-radius:4px}.msg.customer{background:var(--customer);align-self:flex-end;border-bottom-right-radius:4px}.msg.system{align-self:center;color:var(--nike-grey);font-size:12px;background:none}.chat-input{display:flex;gap:8px;padding:12px;border-top:1px solid #eee}.chat-input input{flex:1;padding:10px 12px;border:1px solid #d1d5db;border-radius:10px;font:inherit}.btn{background:var(--accent);color:#fff;border:none;border-radius:10px;padding:10px 18px;font:inherit;font-weight:600;cursor:pointer}.btn:hover{background:var(--accent-dark)}.btn:disabled{opacity:.5;cursor:not-allowed}.image-upload-btn{padding:10px 12px;background:#f3f4f6;font-size:18px;line-height:1}.image-upload-btn:hover{background:#e5e7eb}.image-preview-bar{display:flex;align-items:center;gap:10px;padding:10px 12px;border-top:1px solid #eee;background:#fafafa}.image-preview-thumb{width:44px;height:44px;object-fit:cover;border-radius:8px;border:1px solid #e5e7eb}.image-preview-name{flex:1;font-size:13px;color:var(--nike-grey);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.image-preview-status{font-size:13px;color:var(--accent);font-weight:600}.image-preview-cancel{background:none;border:none;color:var(--nike-grey);font-size:16px;cursor:pointer;padding:4px 8px}.image-preview-cancel:hover{color:#c62828}.msg.bot{white-space:pre-wrap}.notice{background:#fff8e1;border:1px solid #ffe082;color:#8a6d00;border-radius:10px;padding:12px 14px;font-size:13px;margin-top:14px}.call-status{text-align:center;padding:24px}.call-status .dot{font-size:48px}