*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}:root{--blue-600: #2563eb;--blue-700: #1d4ed8;--green-600: #16a34a;--gray-50: #f9fafb;--gray-100: #f3f4f6;--gray-200: #e5e7eb;--gray-400: #9ca3af;--gray-600: #4b5563;--gray-800: #1f2937;--radius: 8px;--shadow: 0 1px 3px rgba(0,0,0,.1), 0 1px 2px rgba(0,0,0,.06)}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:var(--gray-100);color:var(--gray-800);line-height:1.5}.app{max-width:720px;margin:0 auto;padding:32px 16px 48px}.header{text-align:center;margin-bottom:32px}.header h1{font-size:1.75rem;color:var(--blue-600);margin-bottom:4px}.header p{color:var(--gray-600);font-size:.95rem}.uploads{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-bottom:24px}@media(max-width:560px){.uploads{grid-template-columns:1fr}}.uploader{background:#fff;border:2px dashed var(--gray-200);border-radius:var(--radius);padding:24px 16px;text-align:center;cursor:pointer;transition:border-color .15s,background .15s}.uploader:hover,.uploader.dragging{border-color:var(--blue-600);background:var(--gray-50)}.uploader.has-file{border-style:solid;border-color:var(--green-600)}.uploader-label{display:block;font-weight:600;margin-bottom:8px}.uploader-file{display:block;color:var(--green-600);font-size:.9rem;word-break:break-all}.uploader-hint{display:block;color:var(--gray-400);font-size:.85rem}.sheet-list{background:#fff;border-radius:var(--radius);box-shadow:var(--shadow);padding:16px;margin-bottom:24px;transition:outline .15s}.sheet-list.drag-over{outline:2px solid var(--blue-600)}.sheet-list-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:8px}.sheet-list-header h2{font-size:1.1rem}.sheet-list-actions{display:flex;gap:6px}.sheet-list-hint{color:var(--gray-400);font-size:.8rem;margin-bottom:12px}.sheet-list-hint code{background:var(--gray-100);padding:1px 4px;border-radius:3px;font-size:.8rem}.sheet-items{list-style:none;max-height:320px;overflow-y:auto;border:1px solid var(--gray-200);border-radius:var(--radius)}.sheet-item{display:flex;align-items:center;gap:10px;padding:8px 12px;cursor:pointer;transition:background .1s}.sheet-item:hover{background:var(--gray-50)}.sheet-item+.sheet-item{border-top:1px solid var(--gray-100)}.sheet-item input[type=checkbox]{width:16px;height:16px;accent-color:var(--blue-600);cursor:pointer}.sheet-name{flex:1;font-size:.92rem}.sheet-tab{color:var(--gray-400);font-size:.8rem}.sheet-count{text-align:right;color:var(--gray-600);font-size:.85rem;margin-top:8px}.actions{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-bottom:16px}.option-toggle{flex:1 1 100%;display:flex;align-items:flex-start;gap:10px;font-size:.85rem;color:var(--gray-600);cursor:pointer}.option-toggle input{margin-top:3px;flex-shrink:0}.btn{display:inline-flex;align-items:center;justify-content:center;border:none;border-radius:var(--radius);font-size:.9rem;font-weight:600;cursor:pointer;padding:10px 20px;transition:background .15s,opacity .15s;text-decoration:none}.btn:disabled{opacity:.45;cursor:not-allowed}.btn.primary{background:var(--blue-600);color:#fff}.btn.primary:hover:not(:disabled){background:var(--blue-700)}.btn.download{background:var(--green-600);color:#fff}.btn.download:hover{filter:brightness(1.1)}.btn.small{padding:4px 10px;font-size:.8rem;background:var(--gray-100);color:var(--gray-600)}.btn.small:hover{background:var(--gray-200)}.status{color:var(--gray-600);font-size:.85rem;font-style:italic}.merge-log{margin-top:16px;background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius);font-size:.8rem}.merge-log summary{padding:8px 12px;cursor:pointer;color:var(--gray-600);font-weight:600}.merge-log pre{padding:8px 12px;margin:0;max-height:300px;overflow-y:auto;white-space:pre-wrap;word-break:break-all;color:var(--gray-800);border-top:1px solid var(--gray-100);font-family:Consolas,Monaco,monospace;font-size:.78rem;line-height:1.5}