:root{--surface:#eef2f7;--panel:#f8fafc;--paper:#ffffff;--ink:#1e293b;--muted:#64748b;--soft:#94a3b8;--line:#e2e8f0;--line-strong:#cbd5e1;--brand:#1e293b;--accent:#2563eb}*{box-sizing:border-box}body,html{min-height:100%;margin:0;background:var(--surface);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Microsoft YaHei,Arial,sans-serif}button,input{font:inherit}button{border:0}.app-shell{min-height:100svh;display:grid;grid-template-columns:minmax(300px,340px) minmax(720px,1fr);background:var(--surface)}.side-pane{min-width:0;padding:18px;border-right:1px solid var(--line);background:rgba(248,250,252,.94)}.pane-title{margin:0;font-size:22px;font-weight:600;letter-spacing:-.02em}.hint{margin:8px 0 0;color:var(--muted);font-size:13px;line-height:1.5}.section-label{margin:18px 0 8px;color:var(--muted);font-size:11px;font-weight:700;letter-spacing:.08em;text-transform:uppercase}.upload-zone{display:grid;grid-gap:8px;gap:8px;margin-top:18px;padding:16px;border:1px dashed var(--line-strong);border-radius:10px;background:var(--paper);color:var(--ink);cursor:pointer;transition:border-color .16s ease,transform .16s ease,background .16s ease}.upload-zone.is-dragging,.upload-zone:hover{border-color:var(--accent);background:#f8fbff;transform:translateY(-1px)}.upload-zone input{display:none}.upload-zone strong{display:inline-flex;align-items:center;gap:8px;font-size:14px;font-weight:600}.meta-list,.status-line,.upload-zone span{color:var(--muted);font-size:13px;line-height:1.45}.meta-list{display:grid;grid-gap:8px;gap:8px;margin-top:10px}.meta-row{display:flex;justify-content:space-between;gap:16px;border-bottom:1px solid var(--line);padding-bottom:8px}.meta-row strong{color:var(--ink);font-weight:600}.actions{display:grid;grid-template-columns:1fr 1fr;grid-gap:10px;gap:10px;margin-top:18px}.button{min-height:40px;display:inline-flex;align-items:center;justify-content:center;gap:8px;border-radius:8px;background:var(--brand);color:#fff;cursor:pointer;transition:transform .16s ease,opacity .16s ease}.button.secondary{border:1px solid var(--line);background:var(--paper);color:var(--brand)}.button:disabled{cursor:not-allowed;opacity:.55}.button:not(:disabled):hover{transform:translateY(-1px)}.status-line{min-height:40px;margin-top:12px}.spin-icon{animation:spin .9s linear infinite}.workspace{min-width:0;display:flex;flex-direction:column}.workspace-header{min-height:64px;display:flex;align-items:center;justify-content:space-between;gap:18px;padding:14px 22px;border-bottom:1px solid var(--line);background:rgba(248,250,252,.88);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px)}.brand-lockup{display:grid;grid-gap:2px;gap:2px}.brand-lockup strong{color:var(--ink);font-size:14px;letter-spacing:.06em;text-transform:uppercase}.brand-lockup span,.workspace-header>span{color:var(--muted);font-size:13px}.preview-stage{--frame-scale:1;flex:1 1;min-height:0;display:flex;justify-content:center;align-items:flex-start;overflow:auto;overflow-x:hidden;padding:24px 18px;background:#dde4ee}.preview-frame-shell{width:calc(842px * var(--frame-scale));min-height:calc((100svh - 112px) * var(--frame-scale));flex:0 0 auto;overflow:hidden}.preview-frame{width:842px;min-height:calc((100svh - 112px) / var(--frame-scale));border:0;display:block;background:#dde4ee;transform:scale(var(--frame-scale));transform-origin:top left}.empty-preview{height:calc(100svh - 64px);display:grid;place-items:center;color:var(--muted);text-align:center}.empty-preview svg{color:var(--soft)}@keyframes spin{to{transform:rotate(1turn)}}@media (max-width:980px){.app-shell{grid-template-columns:1fr}.side-pane{border-right:0;border-bottom:1px solid var(--line)}.workspace-header{align-items:flex-start;flex-direction:column}.preview-frame-shell{min-height:calc(70svh * var(--frame-scale, 1))}.empty-preview,.preview-frame{min-height:calc(70svh / var(--frame-scale, 1))}}