:root{--bg:#f4f5f7;--card:#fff;--ink:#111827;--muted:#6b7280;--line:#e5e7eb;--accent:#2563eb;--accent2:#1d4ed8;--danger:#dc2626;--radius:18px;--shadow:0 12px 35px rgba(15,23,42,.13);font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;color:var(--ink);background:var(--bg)}*{box-sizing:border-box}body{margin:0;min-height:100dvh;overflow:hidden;background:var(--bg)}button,input,select{font:inherit}.hidden{display:none!important}button{border:0;background:none;color:inherit;cursor:pointer}.app{height:100dvh;display:flex;flex-direction:column}.topbar{height:64px;padding:max(8px,env(safe-area-inset-top)) 10px 6px;background:#111827;color:white;display:flex;align-items:center;gap:6px;flex:none}.icon-button{width:44px;height:44px;border-radius:14px;display:grid;place-items:center;font-size:25px}.icon-button:active{background:rgba(255,255,255,.12)}.top-title{min-width:0;flex:1;display:flex;flex-direction:column}.top-title strong{font-size:17px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.top-title span{font-size:11px;color:#9ca3af}.breadcrumbs{display:flex;gap:4px;overflow-x:auto;padding:8px 12px;background:#fff;border-bottom:1px solid var(--line);scrollbar-width:none}.breadcrumbs button{white-space:nowrap;color:var(--accent);font-size:13px;padding:5px 8px;border-radius:8px}.breadcrumbs button:not(:last-child)::after{content:"›";color:#9ca3af;margin-left:10px}.main-view{position:relative;flex:1;overflow:auto;padding:8px 10px 110px}.file-list{display:flex;flex-direction:column;gap:5px}.file-row{display:flex;align-items:center;gap:12px;padding:11px 8px;border-radius:14px;background:var(--card);min-height:68px;border:1px solid transparent;user-select:none}.file-row:active,.file-row.selected{border-color:#bfdbfe;background:#eff6ff}.file-icon{width:44px;height:44px;border-radius:13px;display:grid;place-items:center;font-size:23px;background:#f3f4f6;flex:none}.file-icon.folder{background:#eff6ff;color:var(--accent)}.file-info{min-width:0;flex:1}.file-name{font-weight:600;font-size:14px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.file-meta{font-size:11px;color:var(--muted);margin-top:4px}.row-more{width:42px;height:42px;border-radius:12px;font-size:24px;color:var(--muted)}.empty{height:60%;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;color:var(--muted);gap:8px}.empty-icon{font-size:48px}.empty strong{color:var(--ink)}.empty span{font-size:13px;max-width:260px}.loading{display:flex;gap:6px;align-items:center;justify-content:center;padding:50px}.loading span{width:9px;height:9px;border-radius:50%;background:var(--accent);animation:pulse .9s infinite alternate}.loading span:nth-child(2){animation-delay:.2s}.loading span:nth-child(3){animation-delay:.4s}@keyframes pulse{to{opacity:.2;transform:translateY(-5px)}}.fab{position:fixed;right:18px;bottom:84px;width:56px;height:56px;border-radius:18px;background:var(--accent);color:white;font-size:30px;box-shadow:0 10px 24px rgba(37,99,235,.35);z-index:5}.fab:active{transform:scale(.96)}.bottom-nav{height:70px;padding:5px 16px max(5px,env(safe-area-inset-bottom));display:flex;background:#fff;border-top:1px solid var(--line);z-index:4;flex:none}.bottom-nav button{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;color:#6b7280;font-size:11px}.bottom-nav button span{font-size:22px}.bottom-nav button.active{color:var(--accent);font-weight:700}.search-panel{display:flex;gap:8px;padding:8px 12px;background:#fff;border-bottom:1px solid var(--line)}.search-panel input{flex:1;border:1px solid var(--line);border-radius:12px;padding:10px 12px;outline:none}.text-button{color:var(--accent);font-weight:600}.login-screen{min-height:100dvh;padding:10vh 24px 24px;background:radial-gradient(circle at top right,#334155,#111827 56%);color:white;display:flex;align-items:center;flex-direction:column}.brand-mark{width:76px;height:76px;display:grid;place-items:center;border-radius:24px;background:linear-gradient(145deg,#60a5fa,#1d4ed8);font-size:38px;font-weight:900;box-shadow:0 16px 50px rgba(37,99,235,.45)}.login-screen h1{margin:20px 0 4px}.login-screen>p{margin:0;color:#cbd5e1}.login-card{width:min(420px,100%);margin-top:34px;background:white;color:var(--ink);border-radius:24px;padding:22px;box-shadow:var(--shadow)}.login-card label{font-size:13px;font-weight:700}.password-row{display:flex;border:1px solid var(--line);border-radius:14px;margin:8px 0 16px;overflow:hidden}.password-row input{flex:1;min-width:0;border:0;outline:0;padding:14px;background:transparent}.login-card small{display:block;text-align:center;color:var(--muted);margin-top:12px}.primary,.secondary{border-radius:12px;padding:11px 16px;font-weight:700}.primary{background:var(--accent);color:white}.primary:active{background:var(--accent2)}.secondary{background:#eef0f3}.wide{width:100%;padding:14px}.compact{padding:9px 13px}.backdrop{position:fixed;inset:0;background:rgba(15,23,42,.45);z-index:20}.action-sheet{position:fixed;z-index:21;left:0;right:0;bottom:0;background:white;border-radius:24px 24px 0 0;padding:8px 16px calc(18px + env(safe-area-inset-bottom));box-shadow:var(--shadow);max-height:80dvh;overflow:auto}.sheet-handle{width:42px;height:5px;background:#d1d5db;border-radius:5px;margin:2px auto 12px}.sheet-title{font-weight:750;padding:5px 8px 12px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.sheet-actions{display:grid;gap:4px}.sheet-action{display:flex;gap:13px;align-items:center;width:100%;padding:13px;border-radius:13px;text-align:left}.sheet-action:active{background:#f3f4f6}.sheet-action .symbol{width:34px;font-size:21px;text-align:center}.sheet-action.danger{color:var(--danger)}.dialog-wrap{position:fixed;inset:0;z-index:30;background:rgba(15,23,42,.5);display:grid;place-items:center;padding:18px}.dialog-card{width:min(430px,100%);background:white;border-radius:22px;padding:20px;box-shadow:var(--shadow)}.dialog-card h2{font-size:19px;margin:0 0 16px}.dialog-card input,.dialog-card select{width:100%;border:1px solid var(--line);border-radius:12px;padding:12px;margin:4px 0 10px}.dialog-card label{display:block;font-size:12px;font-weight:700;color:#374151}.dialog-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:12px}.toast{position:fixed;z-index:40;left:50%;bottom:95px;transform:translateX(-50%);max-width:calc(100% - 32px);background:#111827;color:white;padding:12px 16px;border-radius:13px;box-shadow:var(--shadow);font-size:13px;text-align:center}.toast.error{background:#991b1b}.editor-view{position:fixed;inset:0;background:#e5e7eb;z-index:10;display:flex;flex-direction:column}.editor-head{height:62px;background:#111827;color:white;display:flex;align-items:center;padding:8px;gap:8px}.editor-head>div{flex:1;display:flex;flex-direction:column}.editor-head span{font-size:11px;color:#9ca3af}.editor-workspace{flex:1;overflow:auto;display:grid;place-items:center;padding:18px}.page-stage{position:relative;box-shadow:0 12px 35px rgba(0,0,0,.22);background:white;touch-action:none}.page-stage canvas{display:block;max-width:calc(100vw - 36px);max-height:calc(100dvh - 325px);width:auto;height:auto}.object-tools{position:absolute;left:50%;transform:translateX(-50%);bottom:8px;display:flex;gap:3px;background:rgba(17,24,39,.9);border-radius:12px;padding:4px;white-space:nowrap}.object-tools button{color:white;padding:8px;font-size:12px}.editor-controls{background:#fff;border-top:1px solid var(--line);padding:8px}.control-scroll{display:flex;gap:9px;overflow-x:auto;scrollbar-width:none}.control-scroll label{min-width:105px;font-size:10px;color:var(--muted);font-weight:700}.control-scroll select,.control-scroll input{display:block;width:100%;height:35px;margin-top:3px;border:1px solid var(--line);border-radius:9px;padding:3px}.editor-bottom{min-height:64px;background:#fff;border-top:1px solid var(--line);display:flex;align-items:center;overflow-x:auto;padding:4px 8px calc(4px + env(safe-area-inset-bottom));gap:4px}.tool-button{min-width:54px;padding:4px;display:flex;flex-direction:column;align-items:center;font-size:9px;color:#4b5563}.tool-button span{font-size:21px;color:var(--ink)}.page-count{font-size:12px;white-space:nowrap;padding:8px}.drop-zone{position:fixed;inset:70px 12px 82px;border:3px dashed var(--accent);background:rgba(239,246,255,.95);z-index:8;border-radius:20px;display:grid;place-items:center;color:var(--accent);font-weight:800}@media(min-width:800px){.main-view{padding-left:calc((100% - 760px)/2);padding-right:calc((100% - 760px)/2)}.fab{right:calc((100% - 760px)/2 + 14px)}.bottom-nav{padding-left:calc((100% - 500px)/2);padding-right:calc((100% - 500px)/2)}.page-stage canvas{max-width:650px}}

/* v2 mobile/performance refinements */
html{-webkit-text-size-adjust:100%;overscroll-behavior:none}body{overscroll-behavior:none}.topbar{min-height:60px;height:auto}.main-view{-webkit-overflow-scrolling:touch;contain:layout paint}.file-row{content-visibility:auto;contain-intrinsic-size:68px;will-change:auto}.file-list{gap:4px}.file-icon.doc{background:#eef2ff;color:#1d4ed8;font-weight:800}.file-icon.sheet{background:#ecfdf5;color:#047857;font-weight:800}.file-icon.slides{background:#fff7ed;color:#c2410c;font-weight:800}.file-icon.pdf{background:#fef2f2;color:#b91c1c;font-size:12px;font-weight:900}.file-icon.image{background:#f5f3ff;color:#7c3aed}.row-more{touch-action:manipulation}.bottom-nav button,.fab,.icon-button,.sheet-action{touch-action:manipulation;-webkit-tap-highlight-color:transparent}.office-view{position:fixed;inset:0;z-index:50;background:#fff;display:flex;flex-direction:column}.office-head{height:58px;padding:max(6px,env(safe-area-inset-top)) 8px 5px;background:#111827;color:#fff;display:flex;align-items:center;gap:8px;flex:none}.office-head-title{min-width:0;display:flex;flex-direction:column;flex:1}.office-head-title strong{font-size:15px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.office-head-title span{font-size:10px;color:#9ca3af}.office-host{flex:1;min-height:0;background:#f3f4f6}.office-host iframe{width:100%!important;height:100%!important;border:0!important}.loading{min-height:120px}.toast{pointer-events:none}.dialog-card{max-height:82dvh;overflow:auto}.editor-workspace{padding:10px}.page-stage canvas{max-width:calc(100vw - 20px);max-height:calc(100dvh - 300px)}
@media(max-width:520px){.topbar{padding-left:4px;padding-right:4px}.icon-button{width:42px;height:42px}.top-title strong{font-size:15px}.breadcrumbs{padding:5px 8px}.breadcrumbs button{font-size:12px;padding:5px 6px}.main-view{padding:6px 6px 102px}.file-row{min-height:62px;padding:8px 6px;gap:9px;border-radius:12px}.file-icon{width:40px;height:40px;border-radius:11px}.file-name{font-size:13px}.file-meta{font-size:10px}.row-more{width:38px;height:38px}.bottom-nav{height:64px;padding-left:6px;padding-right:6px}.bottom-nav button{font-size:10px}.bottom-nav button span{font-size:20px}.fab{width:52px;height:52px;right:12px;bottom:74px;border-radius:16px}.login-screen{padding:7vh 16px 18px}.login-card{margin-top:24px;padding:18px;border-radius:20px}.brand-mark{width:68px;height:68px;border-radius:21px}.editor-head{height:56px}.editor-controls{padding:5px}.control-scroll{gap:6px}.control-scroll label{min-width:92px}.editor-bottom{min-height:58px}.tool-button{min-width:48px}.office-head{height:54px}}

/* v2.1 Speed Layer */
.file-icon.has-thumb{overflow:hidden;background:#eef2f7;padding:0}.file-icon.has-thumb img{width:100%;height:100%;object-fit:cover;display:block}.preview-view{position:fixed;inset:0;z-index:45;background:#f4f6f8;display:flex;flex-direction:column}.preview-head{height:58px;padding:max(6px,env(safe-area-inset-top)) 8px 5px;background:#111827;color:#fff;display:flex;align-items:center;gap:8px;flex:none}.preview-head-title{min-width:0;display:flex;flex-direction:column;flex:1}.preview-head-title strong{font-size:14px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.preview-head-title span{font-size:10px;color:#9ca3af}.preview-frame{border:0;width:100%;flex:1;min-height:0;background:#f4f6f8}.file-row{transform:translateZ(0)}