:root{--bg:#f3f4f6;--card:#fff;--text:#111827;--muted:#6b7280;--border:#e5e7eb;--primary:#111827;--primary-text:#fff;--success-bg:#ecfdf5;--success-border:#a7f3d0;--error-bg:#fef2f2;--error-border:#fecaca}*{box-sizing:border-box}body,html{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:Arial,Helvetica,sans-serif}body{min-height:100vh}.page-shell{max-width:1200px;margin:0 auto;padding:24px}.centered{min-height:100vh;display:flex;align-items:center;justify-content:center}.grid{display:grid;grid-template-columns:minmax(0,2fr) minmax(320px,1fr);grid-gap:24px;gap:24px}.main-column,.side-column{display:flex;flex-direction:column;gap:24px}.card{background:var(--card);border:1px solid var(--border);border-radius:18px;padding:24px;box-shadow:0 4px 16px rgba(0,0,0,.04)}.topbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:24px}.badge{display:inline-block;margin-bottom:12px;padding:6px 10px;border-radius:999px;background:#eef2ff;color:#3730a3;font-size:12px;font-weight:700}h1,h2{margin:0 0 8px}p{margin:0}.muted{color:var(--muted)}.small{font-size:12px}.user-line{font-weight:700}.form-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));grid-gap:16px;gap:16px;margin-top:16px}.field{display:flex;flex-direction:column;gap:8px}.field label{font-size:14px;font-weight:700}.field input,.field select{width:100%;height:42px;border:1px solid var(--border);border-radius:10px;padding:0 12px;font-size:14px;background:#fff}.field.span-2{grid-column:span 2}.button{border:1px solid transparent;border-radius:10px;height:42px;padding:0 16px;cursor:pointer;font-weight:700;font-size:14px}.button.primary{background:var(--primary);color:var(--primary-text)}.button.secondary{background:#fff;color:var(--text);border-color:var(--border)}.button.small{height:34px;font-size:13px}.button.full{width:100%}.button:disabled{opacity:.6;cursor:not-allowed}.dropzone{margin-top:16px;display:block;border:2px dashed #cbd5e1;border-radius:16px;padding:42px 16px;text-align:center;background:#fff;cursor:pointer}.drop-title{margin-bottom:8px;font-size:18px;font-weight:700}.hidden-file-input{display:none}.summary{margin-top:16px;font-size:14px;color:var(--muted)}.file-list{margin-top:16px;flex-direction:column}.file-list,.file-row{display:flex;gap:12px}.file-row{justify-content:space-between;align-items:center;border:1px solid var(--border);border-radius:12px;padding:12px 14px}.file-name{font-weight:700;word-break:break-all}.demo-box,.result-box{margin-top:16px;border:1px solid var(--border);border-radius:12px;padding:14px;background:#fafafa}.link-output{margin:8px 0 12px;font-weight:700;word-break:break-all}.alert{border-radius:14px;padding:14px 16px;border:1px solid;font-size:14px}.alert.error{background:var(--error-bg);border-color:var(--error-border)}.alert.success{background:var(--success-bg);border-color:var(--success-border)}.divider{border:0;border-top:1px solid var(--border);margin:18px 0}.bullet-list{display:flex;flex-direction:column;gap:10px}.auth-card{width:100%;max-width:460px}@media (max-width:960px){.form-grid,.grid{grid-template-columns:1fr}.field.span-2{grid-column:span 1}.topbar{flex-direction:column;align-items:flex-start;gap:14px}}