:root { --bg:#f3f6fb; --panel:rgba(255,255,255,.92); --border:rgba(148,163,184,.18); --text:#0f172a; --muted:#64748b; --accent:#2563eb; --accent-soft:rgba(37,99,235,.1); --accent-strong:#1d4ed8; }
    * { box-sizing:border-box; }
    body { margin:0; min-height:100vh; font-family:"PingFang SC","Noto Sans SC","Microsoft YaHei",sans-serif; color:var(--text); background:radial-gradient(circle at top left,rgba(37,99,235,.08),transparent 32%),radial-gradient(circle at bottom right,rgba(14,165,233,.1),transparent 28%),var(--bg); }
    a { color:inherit; text-decoration:none; }
    button, select { font:inherit; }
    .page { width:min(1120px,calc(100% - 32px)); margin:0 auto; padding:22px 0 48px; }
    .topbar { display:flex; align-items:center; justify-content:space-between; gap:16px; margin-bottom:28px; }
    .brand { font-size:1.14rem; font-weight:800; letter-spacing:.03em; }
    .top-actions, .auth-group { display:flex; align-items:center; gap:10px; flex-wrap:wrap; }
    .auth-group[hidden], [hidden] { display:none !important; }
    .auth-status { color:var(--muted); font-size:.92rem; }
    .link-btn, .primary-btn { display:inline-flex; align-items:center; justify-content:center; min-height:40px; padding:0 16px; border-radius:12px; font-size:.92rem; font-weight:600; }
    .link-btn { color:var(--muted); }
    .primary-btn { background:var(--accent-soft); color:var(--accent); }
    h1, h2, p { margin:0; }
    .converter { overflow:hidden; border:1px solid var(--border); border-radius:22px; background:var(--panel); box-shadow:0 28px 80px rgba(15,23,42,.14); }
    .mock-toolbar { display:grid; grid-template-columns:1fr auto 1fr; align-items:center; gap:12px; min-height:52px; padding:0 20px; border-bottom:1px solid var(--border); background:#fff; }
    .mock-dots { display:flex; gap:7px; }
    .mock-dots i { width:9px; height:9px; border-radius:50%; background:#cbd5e1; }
    .mock-toolbar-title { display:flex; align-items:center; gap:12px; white-space:nowrap; }
    .mock-toolbar-title .mock-toolbar-label { color:var(--accent); font-size:.82rem; font-weight:700; letter-spacing:.04em; }
    .mock-toolbar strong { color:#475569; font-size:.85rem; font-weight:650; }
    .mock-toolbar > span { justify-self:end; color:#94a3b8; font-size:.8rem; }
    .mock-workspace { display:grid; grid-template-columns:190px minmax(0,1fr) 190px; min-height:390px; }
    .mock-sidebar { padding:24px 18px; border-right:1px solid var(--border); background:rgba(248,250,252,.75); }
    .mock-preview { border-right:0; border-left:1px solid var(--border); }
    .mock-line { height:10px; margin-bottom:17px; border-radius:99px; background:#e2e8f0; }
    .mock-line.short { width:60%; }
    .mock-line.mid { width:78%; }
    .convert-stage { display:flex; flex-direction:column; align-items:stretch; padding:28px 24px 18px; text-align:center; background:radial-gradient(circle at center,rgba(37,99,235,.065),transparent 58%),#fff; }
    .stage-main { display:flex; flex:1; flex-direction:column; align-items:center; justify-content:center; min-width:0; }
    .stage-icon { display:grid; place-items:center; width:52px; height:52px; border:1px solid rgba(37,99,235,.18); border-radius:15px; background:var(--accent-soft); color:var(--accent); font-size:1.35rem; font-weight:800; }
    .convert-stage h1, .convert-stage h2 { margin-top:16px; font-size:1.125rem; line-height:normal; }
    .convert-stage p { max-width:460px; margin-top:10px; color:var(--muted); font-size:.92rem; line-height:1.7; }
    .convert-stage #stageDescription { font-size:.84rem; }
    .stage-actions { display:flex; justify-content:center; gap:10px; flex-wrap:wrap; margin-top:23px; }
    .stage-actions button, .stage-actions a { display:inline-flex; align-items:center; justify-content:center; min-height:44px; padding:0 18px; border-radius:11px; font-weight:700; cursor:pointer; }
    .stage-primary { border:1px solid var(--accent-strong); background:var(--accent-strong); color:#fff; }
    .stage-secondary { border:1px solid #cbd5e1; background:#fff; color:#334155; }
    .stage-actions button:disabled { opacity:.55; cursor:not-allowed; }
    .selected-file { max-width:min(100%,460px); margin-top:16px !important; padding:10px 14px; border:1px solid #bfdbfe; border-radius:10px; background:#eff6ff; color:#1e40af !important; overflow-wrap:anywhere; }
    .stage-message { min-height:22px; margin-top:13px; color:var(--muted); font-size:.84rem; }
    .formats { margin-top:18px; padding:23px 22px; border:1px solid var(--border); border-radius:22px; background:var(--panel); box-shadow:0 24px 60px rgba(15,23,42,.08); }
    .formats h2 { font-size:1.08rem; }
    .format-buttons { position:relative; display:grid; grid-template-columns:repeat(6,minmax(0,1fr)); gap:14px; width:100%; margin-top:15px; }
    .format-buttons::after { content:""; position:absolute; left:50%; top:50%; width:1px; height:26px; transform:translate(-50%,-50%); background:rgba(148,163,184,.6); pointer-events:none; }
    .format-buttons a { display:inline-flex; align-items:center; justify-content:center; width:100%; min-width:0; min-height:42px; padding:5px 6px; border:1px solid #dbe3ef; border-radius:11px; background:#f8fafc; color:#475569; font-size:.84rem; font-weight:600; text-align:center; white-space:nowrap; cursor:pointer; }
    .format-buttons a[aria-current="page"] { border-color:#bfdbfe; background:#eff6ff; color:var(--accent-strong); font-weight:700; }
    .format-buttons a[aria-current="page"]::before { content:""; display:inline-block; width:6px; height:6px; margin-right:8px; border-radius:50%; background:var(--accent); vertical-align:middle; }
    .format-buttons a:hover { border-color:#93c5fd; }
    .format-buttons a:focus-visible { outline:2px solid var(--accent); outline-offset:2px; }
    .seo-content { margin-top:18px; padding:23px 24px; border:1px solid var(--border); border-radius:22px; background:var(--panel); color:#334155; }
    .seo-content h2 { margin:0 0 12px; font-size:1.08rem; color:var(--text); }
    .seo-content p, .seo-content li { margin:0 0 10px; color:var(--muted); font-size:.9rem; line-height:1.75; }
    .seo-content ul { margin:0; padding-left:20px; }
    .seo-content a { color:var(--accent-strong); text-decoration:underline; text-underline-offset:2px; }
    .convert-stage .stage-footnote { align-self:stretch; max-width:none; margin:18px 0 0; padding:10px 0 0; border:0; border-top:1px solid #e2e8f0; border-radius:0; background:none; color:var(--muted); font-size:.78rem; line-height:1.5; text-align:left; }
    .convert-stage .stage-footnote p { max-width:none; margin:0; color:inherit; font-size:inherit; line-height:inherit; }
    .site-footer { display:flex; justify-content:center; gap:10px; flex-wrap:wrap; margin-top:24px; color:#666; font-size:.82rem; }
    .site-footer img { width:16px; height:16px; vertical-align:middle; }
    @media (max-width:980px) { .format-buttons { grid-template-columns:repeat(3,minmax(0,1fr)); } .format-buttons::after { display:none; } }
    @media (max-width:820px) { .mock-workspace { grid-template-columns:1fr; } .mock-sidebar { display:none; } }
    @media (max-width:600px) { .topbar { align-items:flex-start; flex-direction:column; } .page { width:min(100% - 24px,1120px); padding-top:18px; } .mock-toolbar { gap:6px; padding:0 12px; } .mock-toolbar-title { gap:8px; } .mock-toolbar-title strong, .mock-toolbar > span { display:none; } .convert-stage { min-height:350px; padding:28px 18px 16px; } .format-buttons { grid-template-columns:repeat(2,minmax(0,1fr)); } .format-buttons a { white-space:normal; } }