:root {
    --bg: #ffffff;
    --subtle: #fafafa;
    --hover: #f5f5f5;
    --fg: #0a0a0a;
    --fg-2: #404040;
    --muted: #737373;
    --faint: #a3a3a3;
    --line: #ebebeb;
    --accent: #2563eb;
    --accent-soft: #eff4ff;
    --r: 12px;
    --sans: "Inter", -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
    --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  }
  * { box-sizing: border-box; margin: 0; padding: 0; }
  html { scroll-behavior: smooth; }
  body { background: var(--bg); color: var(--fg); font: 15px/1.65 var(--sans); -webkit-font-smoothing: antialiased; }
  a { color: inherit; text-decoration: none; }
  button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
  .wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

  /* 导航 */
  header { position: sticky; top: 0; z-index: 20; background: rgba(255,255,255,.94); backdrop-filter: saturate(180%) blur(16px); -webkit-backdrop-filter: saturate(180%) blur(16px); border-bottom: 1px solid transparent; transition: border-color .2s; }
  header.scrolled { border-color: var(--line); }
  .nav { height: 60px; display: flex; align-items: center; gap: 32px; }
  .logo { display: flex; align-items: center; gap: 9px; font-weight: 600; font-size: 15px; letter-spacing: -.01em; }
  .logo svg { width: 22px; height: 22px; }
  .nav ul { display: flex; gap: 4px; list-style: none; font-size: 14px; color: var(--muted); }
  .nav ul a { padding: 6px 10px; border-radius: 8px; transition: color .15s, background .15s; }
  .nav ul a:hover { color: var(--fg); background: var(--hover); }
  .nav .right { margin-left: auto; display: flex; gap: 8px; align-items: center; }
  .btn { display: inline-flex; align-items: center; gap: 6px; height: 34px; padding: 0 14px; border-radius: 8px; font-size: 14px; font-weight: 500; background: var(--fg); color: #fff; transition: opacity .15s; }
  .btn:hover { opacity: .85; }
  .btn.line { background: var(--bg); color: var(--fg); border: 1px solid var(--line); }
  .btn.line:hover { background: var(--hover); opacity: 1; }

  /* 首屏 */
  .hero { padding: 96px 0 48px; text-align: center; position: relative; }
  .hero::before { content: ""; position: absolute; inset: 0; z-index: -1; pointer-events: none;
    background: radial-gradient(600px 280px at 50% 0%, var(--accent-soft), transparent 70%); }
  .badge { display: inline-flex; align-items: center; gap: 8px; height: 30px; padding: 0 12px 0 4px; border: 1px solid var(--line); border-radius: 999px; font-size: 13px; color: var(--fg-2); background: var(--bg); transition: border-color .15s; }
  .badge:hover { border-color: #d4d4d4; }
  .badge b { font-weight: 500; font-size: 12px; color: var(--accent); background: var(--accent-soft); padding: 2px 8px; border-radius: 999px; }
  .badge i { font-style: normal; color: var(--faint); }
  h1 { font-size: clamp(38px, 6vw, 60px); line-height: 1.1; font-weight: 600; letter-spacing: -.035em; margin: 24px auto 16px; }
  h1 span { color: var(--faint); }
  .lead { color: var(--muted); font-size: 17px; max-width: 520px; margin: 0 auto; }

  .search { position: relative; max-width: 560px; margin: 36px auto 0; }
  .search input { width: 100%; height: 50px; padding: 0 64px 0 46px; font: inherit; font-size: 15px; color: var(--fg); background: var(--bg); border: 1px solid var(--line); border-radius: 14px; outline: none; box-shadow: 0 1px 2px rgba(0,0,0,.04), 0 4px 16px -4px rgba(0,0,0,.06); transition: border-color .15s, box-shadow .15s; }
  .search input::placeholder { color: var(--faint); }
  .search input::-webkit-search-cancel-button { display: none; }
  .search input:not(:placeholder-shown) ~ kbd { display: none; }
  .search input:focus { border-color: #c7d7fe; box-shadow: 0 0 0 4px var(--accent-soft); }
  .search > svg { position: absolute; left: 16px; top: 15px; width: 20px; height: 20px; color: var(--faint); }
  .search kbd { position: absolute; right: 12px; top: 13px; font: 12px/22px var(--mono); padding: 0 7px; border: 1px solid var(--line); border-radius: 6px; color: var(--muted); background: var(--subtle); }
  .results { position: absolute; left: 0; right: 0; top: 56px; background: var(--bg); border: 1px solid var(--line); border-radius: 14px; box-shadow: 0 12px 40px -12px rgba(0,0,0,.15); padding: 6px; text-align: left; z-index: 5; display: none; max-height: 340px; overflow: auto; }
  .results.show { display: block; }
  .results a { display: flex; justify-content: space-between; gap: 12px; padding: 9px 12px; border-radius: 8px; font-size: 14px; }
  .results a:hover, .results a.active { background: var(--hover); }
  .results small { color: var(--faint); font-size: 12px; white-space: nowrap; }
  .results .empty { padding: 12px; color: var(--muted); font-size: 14px; }

  .quick { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-top: 20px; }
  .quick a { font-size: 13px; color: var(--muted); padding: 4px 12px; border: 1px solid var(--line); border-radius: 999px; transition: color .15s, border-color .15s; }
  .quick a:hover { color: var(--fg); border-color: #d4d4d4; }

  /* 区块 */
  section { padding: 56px 0; }
  .sec-head { display: flex; align-items: end; justify-content: space-between; gap: 16px; margin-bottom: 28px; flex-wrap: wrap; }
  h2 { font-size: 24px; font-weight: 600; letter-spacing: -.02em; }
  .sec-head p { color: var(--muted); font-size: 14px; margin-top: 4px; }
  .more { font-size: 14px; color: var(--muted); display: inline-flex; gap: 4px; align-items: center; }
  .more:hover { color: var(--fg); }

  /* 学习方向 */
  .cats { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--line); border-radius: 16px; overflow: hidden; }
  .cat { padding: 28px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); transition: background .15s; display: flex; flex-direction: column; gap: 14px; }
  .cat:nth-child(3n) { border-right: 0; }
  .cat:nth-last-child(-n+3) { border-bottom: 0; }
  .cat:hover { background: var(--subtle); }
  .cat:hover .arrow { opacity: 1; transform: translateX(0); }
  .cat .top { display: flex; justify-content: space-between; align-items: center; }
  .cat .ico { width: 36px; height: 36px; border-radius: 10px; border: 1px solid var(--line); display: grid; place-items: center; color: var(--fg-2); background: var(--bg); }
  .cat .ico svg { width: 18px; height: 18px; }
  .cat .arrow { color: var(--faint); opacity: 0; transform: translateX(-4px); transition: all .2s; }
  .cat h3 { font-size: 16px; font-weight: 600; letter-spacing: -.01em; }
  .cat p { color: var(--muted); font-size: 14px; margin-top: 2px; }
  .cat .meta { font-size: 12.5px; color: var(--faint); margin-top: auto; }

  /* 最新 */
  .tabs { display: flex; gap: 2px; padding: 3px; background: var(--hover); border-radius: 10px; }
  .tabs button { font-size: 13px; padding: 5px 12px; border-radius: 7px; color: var(--muted); }
  .tabs button[aria-selected="true"] { background: var(--bg); color: var(--fg); box-shadow: 0 1px 2px rgba(0,0,0,.08); }
  .feed { border-top: 1px solid var(--line); }
  .item { display: grid; grid-template-columns: 90px 1fr auto; gap: 20px; align-items: center; padding: 18px 4px; border-bottom: 1px solid var(--line); transition: background .15s; }
  .item:hover { background: var(--subtle); }
  .item time { font: 13px var(--mono); color: var(--faint); }
  .item h4 { font-size: 15px; font-weight: 500; }
  .item p { color: var(--muted); font-size: 13.5px; margin-top: 2px; }
  .pill { font-size: 12px; color: var(--muted); padding: 2px 10px; border: 1px solid var(--line); border-radius: 999px; white-space: nowrap; }
  .pill.new { color: var(--accent); border-color: #c7d7fe; background: var(--accent-soft); }
  .item[hidden] { display: none; }

  /* 导航 */
  .groups { display: grid; gap: 28px; }
  .group h5 { font-size: 13px; font-weight: 500; color: var(--muted); margin-bottom: 10px; }
  .sites { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
  .site { display: flex; align-items: center; gap: 12px; padding: 12px 14px; border: 1px solid var(--line); border-radius: var(--r); transition: border-color .15s, background .15s; }
  .site:hover { border-color: #d4d4d4; background: var(--subtle); }
  .site .fav { width: 32px; height: 32px; border-radius: 8px; flex: none; display: grid; place-items: center; font-size: 13px; font-weight: 600; color: #fff; }
  .site b { display: block; font-size: 14px; font-weight: 500; }
  .site small { display: block; color: var(--faint); font-size: 12.5px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .site > div { min-width: 0; }

  /* 提示词 */
  .prompts { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
  .prompt { border: 1px solid var(--line); border-radius: var(--r); padding: 20px; display: flex; flex-direction: column; gap: 12px; }
  .prompt .top { display: flex; justify-content: space-between; align-items: center; }
  .prompt h4 { font-size: 15px; font-weight: 600; }
  .prompt pre { font: 13.5px/1.75 var(--sans); color: var(--fg-2); white-space: pre-wrap; background: var(--subtle); border: 1px solid var(--line); border-radius: 8px; padding: 12px; flex: 1; }
  .copy { font-size: 12.5px; color: var(--muted); padding: 3px 10px; border: 1px solid var(--line); border-radius: 7px; transition: all .15s; }
  .copy:hover { color: var(--fg); border-color: #d4d4d4; }
  .copy.done { color: #16a34a; border-color: #bbf7d0; background: #f0fdf4; }

  /* 知识库 CTA */
  .kb { border: 1px solid var(--line); border-radius: 16px; padding: 40px; display: flex; justify-content: space-between; align-items: center; gap: 24px; flex-wrap: wrap;
    background: linear-gradient(180deg, var(--subtle), var(--bg)); }
  .kb h2 { font-size: 22px; }
  .kb p { color: var(--muted); font-size: 14.5px; margin-top: 6px; max-width: 520px; }
  .kb form { display: flex; gap: 8px; }
  .kb input { height: 34px; width: 240px; padding: 0 12px; font: inherit; font-size: 14px; border: 1px solid var(--line); border-radius: 8px; outline: none; background: var(--bg); }
  .kb input:focus { border-color: #c7d7fe; box-shadow: 0 0 0 3px var(--accent-soft); }
  .kb .ok { font-size: 13px; color: #16a34a; margin-top: 8px; min-height: 1.4em; }

  footer { border-top: 1px solid var(--line); margin-top: 72px; }
  footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; padding-top: 28px; padding-bottom: 40px; font-size: 13px; color: var(--faint); }
  footer nav { display: flex; gap: 20px; }
  footer a:hover { color: var(--fg); }

  .fade { opacity: 0; transform: translateY(8px); transition: opacity .5s ease, transform .5s ease; }
  .fade.in { opacity: 1; transform: none; }
  @media (prefers-reduced-motion: reduce) { .fade { opacity: 1; transform: none; transition: none; } }

  @media (max-width: 900px) {
    .nav ul { display: none; }
    .cats, .prompts { grid-template-columns: 1fr 1fr; }
    .cat:nth-child(3n) { border-right: 1px solid var(--line); }
    .cat:nth-child(2n) { border-right: 0; }
    .cat:nth-last-child(-n+3) { border-bottom: 1px solid var(--line); }
    .cat:nth-last-child(-n+2) { border-bottom: 0; }
    .sites { grid-template-columns: repeat(2, 1fr); }
  }
  @media (max-width: 600px) {
    .wrap { padding: 0 16px; }
    .hero { padding: 64px 0 48px; }
    section { padding: 56px 0; }
    .cats, .prompts { grid-template-columns: 1fr; }
    .cat { border-right: 0 !important; border-bottom: 1px solid var(--line) !important; }
    .cat:last-child { border-bottom: 0 !important; }
    .item { grid-template-columns: 1fr auto; gap: 4px 12px; }
    .item time { grid-column: 1 / -1; }
    .kb { padding: 28px 20px; }
    .kb form { width: 100%; }
    .kb input { flex: 1; width: auto; }
    .nav .right .line { display: none; }
  }

  /* ===== 资讯/教程列表通用 ===== */
  .item { cursor: pointer; text-align: left; width: 100%; }
  .item .src { font-size: 12px; color: var(--faint); margin-top: 4px; display: flex; gap: 8px; align-items: center; }
  .item .src .en { font: 10.5px/1 var(--mono); padding: 2px 5px; border: 1px solid var(--line); border-radius: 4px; }
  .pill.tut { color: #15803d; border-color: #bbf7d0; background: #f0fdf4; }
  .feed-empty { padding: 32px 4px; color: var(--muted); font-size: 14px; }
  .feed-more { display: flex; justify-content: center; margin-top: 24px; }
  .updated { font-size: 12.5px; color: var(--faint); }
  .skeleton { height: 64px; border-bottom: 1px solid var(--line); background: linear-gradient(90deg, var(--subtle), var(--hover), var(--subtle)); background-size: 200% 100%; animation: shimmer 1.2s infinite; }
  @keyframes shimmer { to { background-position: -200% 0; } }

  /* ===== 阅读面板 ===== */
  .sheet-mask { position: fixed; inset: 0; background: rgba(10,10,10,.28); opacity: 0; pointer-events: none; transition: opacity .2s; z-index: 50; }
  .sheet { position: fixed; top: 0; right: 0; bottom: 0; width: min(520px, 100%); background: var(--bg); border-left: 1px solid var(--line); transform: translateX(100%); visibility: hidden; transition: transform .25s cubic-bezier(.2,.8,.2,1); z-index: 51; display: flex; flex-direction: column; }
  .sheet.open { transform: none; visibility: visible; box-shadow: -24px 0 60px -30px rgba(0,0,0,.25); }
  .sheet { transition: transform .25s cubic-bezier(.2,.8,.2,1), visibility .25s; }
  .sheet-mask.open { opacity: 1; pointer-events: auto; }
  .sheet-top { display: flex; justify-content: space-between; align-items: center; height: 60px; padding: 0 24px; border-bottom: 1px solid var(--line); font-size: 13px; color: var(--muted); }
  .sheet-close { width: 32px; height: 32px; border-radius: 8px; display: grid; place-items: center; color: var(--muted); font-size: 18px; }
  .sheet-close:hover { background: var(--hover); color: var(--fg); }
  .sheet-body { padding: 32px 28px; overflow: auto; flex: 1; }
  .sheet-body .meta { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; font-size: 13px; color: var(--muted); }
  .sheet-body h3 { font-size: 22px; line-height: 1.4; font-weight: 600; letter-spacing: -.02em; margin: 14px 0 18px; }
  .sheet-body .sum { font-size: 15.5px; line-height: 1.85; color: var(--fg-2); }
  .sheet-body .sum.none { color: var(--faint); }
  .sheet-body .note { margin-top: 28px; padding: 14px 16px; border-radius: 10px; background: var(--subtle); border: 1px solid var(--line); font-size: 13px; color: var(--muted); }
  .sheet-foot { padding: 16px 28px 24px; border-top: 1px solid var(--line); display: flex; gap: 8px; }
  .sheet-foot .btn { height: 40px; padding: 0 18px; }

  /* ===== 文章页 ===== */
  .article { max-width: 720px; margin: 0 auto; padding: 48px 24px 24px; }
  .crumbs { font-size: 13px; color: var(--faint); display: flex; gap: 6px; }
  .crumbs a:hover { color: var(--fg); }
  .article h1 { font-size: clamp(28px, 4.4vw, 40px); text-align: left; margin: 18px 0 14px; line-height: 1.25; letter-spacing: -.03em; }
  .article .byline { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; font-size: 13px; color: var(--muted); padding-bottom: 28px; border-bottom: 1px solid var(--line); }
  .toc { margin: 28px 0 8px; padding: 18px 20px; border: 1px solid var(--line); border-radius: 12px; background: var(--subtle); font-size: 14px; }
  .toc b { display: block; font-size: 12.5px; color: var(--muted); font-weight: 500; margin-bottom: 8px; }
  .toc ol { margin: 0; padding-left: 20px; display: grid; gap: 4px; }
  .toc a { color: var(--fg-2); }
  .toc a:hover { color: var(--accent); }
  .prose { font-size: 16px; line-height: 1.9; color: var(--fg-2); }
  .prose > * + * { margin-top: 18px; }
  .prose .lead { font-size: 17.5px; color: var(--fg); margin-top: 28px; }
  .prose h2 { font-size: 22px; font-weight: 600; color: var(--fg); letter-spacing: -.02em; margin-top: 48px; scroll-margin-top: 80px; }
  .prose h3 { font-size: 17px; font-weight: 600; color: var(--fg); margin-top: 30px; }
  .prose ul, .prose ol { padding-left: 22px; }
  .prose li + li { margin-top: 6px; }
  .prose a { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; text-decoration-color: #c7d7fe; }
  .prose strong { color: var(--fg); font-weight: 600; }
  .prose code { font: 13.5px var(--mono); background: var(--hover); padding: 2px 6px; border-radius: 5px; color: var(--fg); }
  .prose pre { background: var(--subtle); border: 1px solid var(--line); border-radius: 10px; padding: 16px 18px; overflow: auto; }
  .prose pre code { background: none; padding: 0; font-size: 13.5px; line-height: 1.75; white-space: pre-wrap; word-break: break-word; }
  .prose blockquote { border-left: 3px solid var(--line); padding-left: 16px; color: var(--muted); }
  .prose table { width: 100%; border-collapse: collapse; font-size: 14.5px; display: block; overflow-x: auto; }
  .prose th, .prose td { border: 1px solid var(--line); padding: 9px 12px; text-align: left; vertical-align: top; }
  .prose th { background: var(--subtle); color: var(--fg); font-weight: 600; white-space: nowrap; }
  .prose .note, .prose .warn { padding: 14px 16px; border-radius: 10px; font-size: 15px; border: 1px solid; }
  .prose .note { background: var(--accent-soft); border-color: #dbe5fe; }
  .prose .warn { background: #fffbeb; border-color: #fde68a; }
  .prose .note b, .prose .warn b { color: var(--fg); margin-right: 6px; }
  .prose .steps ol { counter-reset: s; list-style: none; padding: 0; }
  .prose .steps li { counter-increment: s; position: relative; padding-left: 38px; }
  .prose .steps li::before { content: counter(s); position: absolute; left: 0; top: 2px; width: 24px; height: 24px; border-radius: 50%; background: var(--fg); color: #fff; font-size: 12.5px; display: grid; place-items: center; }
  .next { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 56px 0 0; }
  .next a { border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; transition: border-color .15s, background .15s; }
  .next a:hover { border-color: #d4d4d4; background: var(--subtle); }
  .next small { color: var(--faint); font-size: 12.5px; }
  .next b { display: block; font-size: 14.5px; font-weight: 500; margin-top: 2px; }
  .page-head { padding: 56px 0 8px; }
  .page-head h1 { text-align: left; font-size: clamp(30px, 4.6vw, 44px); margin: 0 0 8px; }
  .page-head p { color: var(--muted); }
  @media (max-width: 600px) { .next { grid-template-columns: 1fr; } .article { padding: 32px 16px 16px; } .sheet-body { padding: 24px 20px; } }
  .updated:not(:empty)::before { content: " · "; }

  .item p { display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
  .prose .lead { max-width: none; margin-left: 0; margin-right: 0; text-align: left; }
  .toc ol { list-style: none; padding-left: 0; }
  .page-head { padding-left: 24px; padding-right: 24px; }
  @media (max-width: 600px) { .page-head { padding-left: 16px; padding-right: 16px; } }
  .legal .byline { align-items: center; }
  .legal .prose h2 { font-size: 18px; margin-top: 36px; }
  [hidden] { display: none !important; }
  .article h1 span { color: inherit; }
  .prose > div[lang] > * + * { margin-top: 18px; }
  .prose > div[lang] > .lead { margin-top: 28px; }
  .prose > div[lang] > h2 { margin-top: 36px; }

  /* ===== 出海频道 ===== */
  .band { display: flex; align-items: center; gap: 16px; margin-top: 12px; padding: 16px 20px; border: 1px solid var(--line); border-radius: 14px; transition: background .15s, border-color .15s; }
  .band:hover { background: var(--subtle); border-color: #d4d4d4; }
  .band-tag { font-size: 12.5px; font-weight: 500; color: var(--accent); background: var(--accent-soft); padding: 3px 10px; border-radius: 999px; white-space: nowrap; }
  .band-text { font-size: 14px; color: var(--fg-2); }
  .band-go { margin-left: auto; font-size: 14px; color: var(--muted); white-space: nowrap; }
  .route { border: 1px solid var(--line); border-radius: 16px; overflow: hidden; }
  .step { display: grid; grid-template-columns: 56px 1fr auto; gap: 16px; align-items: center; padding: 22px 24px; border-bottom: 1px solid var(--line); transition: background .15s; }
  .step:last-child { border-bottom: 0; }
  .step:hover { background: var(--subtle); }
  .step .no { font: 600 15px var(--mono); color: var(--faint); width: 40px; height: 40px; border: 1px solid var(--line); border-radius: 10px; display: grid; place-items: center; background: var(--bg); }
  .step:hover .no { color: var(--accent); border-color: #c7d7fe; }
  .step h3 { font-size: 16px; font-weight: 600; }
  .step p { color: var(--muted); font-size: 14px; margin-top: 2px; }
  .step .meta { font-size: 13px; color: var(--faint); white-space: nowrap; }
  .route-note { margin-top: 20px; padding: 20px 22px; border-radius: 14px; background: var(--subtle); border: 1px solid var(--line); font-size: 14.5px; color: var(--fg-2); }
  .route-note b { display: block; margin-bottom: 6px; color: var(--fg); }
  .route-note .small { font-size: 13px; color: var(--muted); margin-top: 10px; }
  @media (max-width: 600px) {
    .band { flex-wrap: wrap; } .band-go { margin-left: 0; }
    .step { grid-template-columns: 40px 1fr; padding: 18px 16px; } .step .meta { grid-column: 2; }
  }
  /* GEO：开头速答块 */
  .prose .answer { margin: 0 0 24px; padding: 16px 18px; border-left: 3px solid var(--accent); background: var(--accent-soft); border-radius: 0 10px 10px 0; font-size: 15.5px; line-height: 1.8; color: var(--fg); }
  .prose .answer b { color: var(--accent); margin-right: 4px; }