:root{
    --bg:#FAF9F5;
    --bg-soft:#F0EEE6;
    --bg-wash:#F5F2E9;
    --card:#FFFFFF;
    --ink:#1F1E1D;
    --ink-2:#4E4A40;
    --muted:#8A8578;
    --line:#E5E1D4;
    --line-soft:#EDEAE0;
    --accent:#D97757;
    --accent-deep:#C05F3F;
    --accent-soft:#F6E3DB;
    --nav-bg:rgba(250,249,245,.86);
    --badge-bg:rgba(255,255,255,.6);
    --fic-bg:#FFFFFF;
    --field-bg:#FFFFFF;
    --ghost-hover-bg:#FFFFFF;
    --ghost-hover-line:#D8D3C4;
    --btn-solid-bg:#1F1E1D;
    --btn-solid-fg:#FBFAF7;
    --logo-ink:#23221F;
    --radius:16px;
    --serif:Georgia,"Times New Roman","Songti SC",STSong,"Noto Serif CJK SC","Noto Serif SC",serif;
    --sans:-apple-system,BlinkMacSystemFont,"PingFang SC","Helvetica Neue","Noto Sans CJK SC","Microsoft YaHei",sans-serif;
  }
  html[data-theme="dark"]{
    --bg:#262624;
    --bg-soft:#2E2D2A;
    --bg-wash:#2A2927;
    --card:#30302E;
    --ink:#F0EEE6;
    --ink-2:#C9C4B6;
    --muted:#8F8A7D;
    --line:#413F39;
    --line-soft:#383630;
    --accent:#D97757;
    --accent-deep:#E08663;
    --accent-soft:rgba(217,119,87,.22);
    --nav-bg:rgba(38,38,36,.86);
    --badge-bg:rgba(48,48,46,.55);
    --fic-bg:#262624;
    --field-bg:#262624;
    --ghost-hover-bg:rgba(255,255,255,.06);
    --ghost-hover-line:#4A4840;
    --btn-solid-bg:#F0EEE6;
    --btn-solid-fg:#23221E;
    --logo-ink:#E8E5DB;
  }
  *{margin:0;padding:0;box-sizing:border-box}
  html{scroll-behavior:smooth}
  body{
    font-family:var(--sans);
    background:var(--bg);
    color:var(--ink);
    line-height:1.7;
    -webkit-font-smoothing:antialiased;
    transition:background-color .25s ease, color .25s ease;
  }
  ::selection{background:var(--accent-soft)}
  a{color:inherit;text-decoration:none}
  .container{max-width:1120px;margin:0 auto;padding:0 28px}
  :where(a,button,input,textarea,select,summary):focus-visible{
    outline:2px solid #fff;outline-offset:2px;box-shadow:0 0 0 6px #0b3d91
  }
  /* 输入框聚焦时不使用全局双线焦点环,由 .modal input:focus 提供 border 聚焦样式 */
  :where(input,textarea,select):focus-visible{
    outline:none;box-shadow:none
  }

  /* ============ 顶部导航 ============ */
  .nav-wrap{
    position:sticky;top:0;z-index:50;
    background:var(--nav-bg);
    backdrop-filter:blur(14px);
    -webkit-backdrop-filter:blur(14px);
    border-bottom:1px solid var(--line-soft);
  }
  nav{display:flex;align-items:center;justify-content:space-between;height:68px}
  .brand{display:flex;align-items:center;gap:10px}
  .brand .mark{width:32px;height:32px;flex:none}
  .brand .name{font-family:var(--serif);font-size:19.5px;font-weight:700;letter-spacing:.04em}
  .brand .name em{font-style:normal;color:var(--accent)}
  .nav-links{display:flex;gap:30px;font-size:14.5px;color:var(--ink-2)}
  .nav-links a:hover{color:var(--ink)}
  .nav-actions{display:flex;align-items:center;gap:12px}
  .btn{
    display:inline-flex;align-items:center;justify-content:center;gap:8px;
    border-radius:999px;cursor:pointer;transition:all .18s ease;
    font-family:var(--sans);font-size:14.5px;line-height:1;border:1px solid transparent;
  }
  .btn-ghost{padding:10px 20px;border-color:var(--line);color:var(--ink);background:transparent}
  .btn-ghost:hover{background:var(--ghost-hover-bg);border-color:var(--ghost-hover-line)}
  .btn-dark{padding:11px 21px;background:var(--btn-solid-bg);color:var(--btn-solid-fg)}
  .btn-dark:hover{opacity:.88}
  .btn-accent{padding:14px 28px;background:var(--accent);color:#fff;font-size:15.5px}
  .btn-accent:hover{background:var(--accent-deep);transform:translateY(-1px);box-shadow:0 6px 18px rgba(217,119,87,.28)}
  .btn-lg-ghost{padding:14px 28px;border-color:var(--line);font-size:15.5px;background:transparent}
  .btn-lg-ghost:hover{background:var(--ghost-hover-bg);border-color:var(--ghost-hover-line)}
  .theme-toggle{width:40px;height:40px;padding:0;flex:none}
  .theme-toggle svg{width:17px;height:17px}
  .theme-toggle .ic-sun{display:none}
  html[data-theme="dark"] .theme-toggle .ic-moon{display:none}
  html[data-theme="dark"] .theme-toggle .ic-sun{display:block}

  /* ============ Hero ============ */
  .hero{
    position:relative;
    padding:88px 0 64px;
    text-align:center;
    background:
      radial-gradient(900px 420px at 20% -8%, rgba(217,119,87,.07), transparent 60%),
      radial-gradient(1100px 520px at 82% -12%, rgba(214,197,161,.22), transparent 62%);
  }
  html[data-theme="dark"] .hero{
    background:
      radial-gradient(900px 420px at 20% -8%, rgba(217,119,87,.09), transparent 60%),
      radial-gradient(1100px 520px at 82% -12%, rgba(133,120,95,.13), transparent 62%);
  }
  .hero-badge{
    display:inline-flex;align-items:center;gap:8px;
    font-size:13px;color:var(--ink-2);
    border:1px solid var(--line);border-radius:999px;
    padding:7px 16px;background:var(--badge-bg);
    margin-bottom:34px;letter-spacing:.02em;
  }
  .hero-badge .spark{color:var(--accent);font-size:14px}
  h1{
    font-family:var(--serif);
    font-size:clamp(38px,6.2vw,62px);
    font-weight:600;
    letter-spacing:.045em;
    line-height:1.32;
    margin:0 auto 26px;
    max-width:820px;
  }
  h1 .accent{color:var(--accent)}
  h1 .ph1{display:inline-block}
  .hero-sub,.sec-sub{text-wrap:balance}
  .hero-sub{
    font-size:17px;color:var(--ink-2);
    max-width:600px;margin:0 auto 40px;
  }
  .hero-cta{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;margin-bottom:64px}

  /* ============ 模型墙 ============ */
  .models{padding:88px 0 30px}
  .sec-head{text-align:center;margin-bottom:48px}
  .sec-kicker{
    font-size:13px;letter-spacing:.28em;color:var(--accent);
    text-transform:uppercase;margin-bottom:14px;
  }
  h2{
    font-family:var(--serif);
    font-size:clamp(26px,3.6vw,36px);
    font-weight:600;letter-spacing:.05em;line-height:1.4;
  }
  .sec-sub{font-size:15.5px;color:var(--ink-2);margin-top:14px}
  .logo-grid{
    display:grid;
    grid-template-columns:repeat(4,1fr);
    gap:14px;
    max-width:760px;
    margin:0 auto;
  }
  .logo-tile{
    background:var(--card);
    border:1px solid var(--line-soft);
    border-radius:var(--radius);
    padding:22px 10px 18px;
    display:flex;flex-direction:column;align-items:center;gap:11px;
    transition:all .22s ease;
    color:var(--logo-ink); /* currentColor for mono marks */
  }
  .logo-tile svg,
  .logo-tile img{width:34px;height:34px;opacity:.94;transition:transform .25s ease}
  .logo-tile img{object-fit:contain}
  .logo-tile:hover{transform:translateY(-3px);border-color:var(--line);box-shadow:0 12px 28px -14px rgba(31,30,29,.16)}
  .logo-tile:hover svg,
  .logo-tile:hover img{opacity:1;transform:scale(1.06)}
  .logo-tile .lname{font-size:13px;color:var(--ink-2);letter-spacing:.02em}
  .models-note{
    text-align:center;font-size:12px;color:#A9A498;margin-top:26px;
  }

  /* ============ 三大特点 ============ */
  .features{padding:72px 0 88px}
  .feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
  .feature-card{
    background:var(--bg-soft);
    border:1px solid var(--line-soft);
    border-radius:20px;
    padding:30px 28px;
  }
  .feature-card .fic{
    width:40px;height:40px;border-radius:12px;
    background:var(--fic-bg);border:1px solid var(--line-soft);
    display:flex;align-items:center;justify-content:center;
    margin-bottom:18px;color:var(--accent);
  }
  .feature-card h3{
    font-family:var(--serif);font-size:19px;font-weight:600;
    letter-spacing:.06em;margin-bottom:8px;
  }
  .feature-card p{font-size:14.5px;color:var(--ink-2)}

  /* ============ 引言带 ============ */
  .quote-band{
    background:var(--bg-soft);
    border-top:1px solid var(--line-soft);
    border-bottom:1px solid var(--line-soft);
    padding:84px 0;text-align:center;
  }
  .quote-band .q{
    font-family:var(--serif);
    font-size:clamp(22px,3vw,30px);
    letter-spacing:.12em;line-height:1.7;
    max-width:700px;margin:0 auto 14px;
  }
  .quote-band .q .qm{color:var(--accent)}
  .quote-band .by{font-size:13.5px;color:var(--muted);letter-spacing:.2em;margin-bottom:40px}
  .quote-band .cta-line{display:flex;justify-content:center}

  /* ============ 页脚 ============ */
  footer{padding:56px 0 36px}
  .foot-top{
    display:flex;justify-content:space-between;gap:40px;flex-wrap:wrap;
    padding-bottom:36px;border-bottom:1px solid var(--line-soft);
  }
  .foot-brand{max-width:300px}
  .foot-brand .brand{margin-bottom:14px}
  .foot-brand p{font-size:13.5px;color:var(--muted)}
  .foot-cols{display:flex;gap:72px;flex-wrap:wrap}
  .foot-col h4{font-size:13px;color:var(--muted);font-weight:500;letter-spacing:.14em;margin-bottom:14px}
  .foot-col a{display:block;font-size:14px;color:var(--ink-2);margin-bottom:10px}
  .foot-col a:hover{color:var(--ink)}
  .foot-bar{
    display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;
    padding-top:26px;font-size:12.5px;color:#A9A498;
  }
  .foot-bar a:hover{color:var(--ink-2)}

  /* ============ 响应式 ============ */
  @media (max-width:960px){
    .feature-grid{grid-template-columns:1fr}
    .nav-links{display:none}
  }
  @media (max-width:620px){
    .logo-grid{grid-template-columns:repeat(2,1fr);max-width:420px}
    .hero{padding:56px 0 48px}
    .container{padding:0 20px}
    .foot-cols{gap:40px}
    nav{gap:10px}
    .brand{min-width:0;gap:7px}
    .brand .mark{width:28px;height:28px}
    .brand .name{font-size:17px;letter-spacing:.01em;white-space:nowrap}
    .nav-actions{gap:8px;flex:none}
    .nav-actions .btn-dark{display:none}
    .nav-actions .btn-ghost:not(.theme-toggle){padding:10px 15px}
    .hero-badge{max-width:100%;justify-content:center;flex-wrap:wrap;white-space:normal;line-height:1.45}
    h1{font-size:clamp(32px,10vw,42px);letter-spacing:.02em;line-height:1.28}
    h1 .ph1{display:inline}
    .hero-sub,.sec-sub,.models-note,.feature-card p{overflow-wrap:anywhere}
  }
  @media (max-width:430px){
    .logo-grid{grid-template-columns:repeat(2,1fr)}
    .container{padding-left:16px;padding-right:16px}
    .brand .name{font-size:15.5px}
    .nav-actions .btn-ghost:not(.theme-toggle){padding:10px 13px}
  }

  @media (prefers-reduced-motion:reduce){
    html{scroll-behavior:auto}
    *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;scroll-behavior:auto!important;transition-duration:.01ms!important}
  }

  /* ============ 登录/注册弹窗(真实接口,视觉沿用设计稿) ============ */
  .sr-only{
    position:absolute;width:1px;height:1px;padding:0;margin:-1px;
    overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0;
  }
  .modal-overlay{
    position:fixed;inset:0;z-index:100;
    background:rgba(31,30,29,.44);
    backdrop-filter:blur(6px);
    -webkit-backdrop-filter:blur(6px);
    display:none;align-items:center;justify-content:center;padding:20px;
  }
  .modal-overlay.open{display:flex;animation:fadein .18s ease}
  @keyframes fadein{from{opacity:0}to{opacity:1}}
  .modal{
    width:100%;max-width:408px;
    background:var(--bg);
    border:1px solid var(--line-soft);
    border-radius:26px;
    padding:40px 36px 26px;
    position:relative;text-align:center;
    box-shadow:0 30px 80px -20px rgba(31,30,29,.35);
    animation:pop .22s ease;
  }
  @keyframes pop{from{transform:translateY(10px) scale(.985);opacity:.6}to{transform:none;opacity:1}}
  .modal .close{
    position:absolute;top:16px;right:18px;border:none;background:none;
    font-size:20px;color:var(--muted);cursor:pointer;line-height:1;padding:6px;
  }
  .modal .close:hover{color:var(--ink)}
  .modal .mark{width:38px;height:38px;margin:0 auto 16px;display:block}
  .modal h3{font-family:var(--serif);font-size:24px;font-weight:600;letter-spacing:.06em;margin-bottom:8px}
  .modal .msub{font-size:14px;color:var(--ink-2);margin-bottom:22px}
  .auth-tabs{display:flex;gap:6px;background:var(--bg-soft);border:1px solid var(--line-soft);border-radius:999px;padding:4px;margin-bottom:18px}
  .auth-tab{flex:1;border:none;border-radius:999px;padding:8px 0;font-size:14px;color:var(--ink-2);background:transparent;cursor:pointer;transition:all .15s ease;font-family:var(--sans)}
  .auth-tab.active{background:var(--card);color:var(--ink);font-weight:500;box-shadow:0 1px 4px rgba(31,30,29,.08)}
  .modal input{
    width:100%;padding:13px 16px;font-size:15px;font-family:var(--sans);
    border:1px solid var(--line);border-radius:12px;background:var(--field-bg);color:var(--ink);
    outline:none;transition:border-color .15s, box-shadow .15s;margin-bottom:12px;
  }
  .modal input::placeholder{color:#B3AEA1}
  .modal input:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(217,119,87,.15)}
  .modal input.hidden-f{display:none}
  .auth-extra.hidden-f{display:none}
  .captcha-box{margin:2px 0 12px;padding:10px;border:1px solid var(--line-soft);border-radius:12px;background:var(--bg-soft);text-align:left}
  .captcha-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:8px;font-size:12px;color:var(--ink-2)}
  .captcha-head button{border:0;background:none;color:var(--accent);font:inherit;cursor:pointer;text-decoration:underline;text-underline-offset:3px}
  .captcha-row{display:flex;align-items:center;gap:8px}
  .captcha-row img{width:150px;height:48px;display:block;flex:0 0 150px;border:1px solid var(--line);border-radius:7px;background:#fff}
  .captcha-row input{margin:0;min-width:0}
  .auth-notice{margin:-3px 0 12px;text-align:left;color:var(--ink-2);font-size:12px;line-height:1.65}
  .modal .btn-full{width:100%;padding:13px 0;font-size:15px}
  .am-error{min-height:20px;font-size:13px;color:#C0392B;margin-top:10px}
  html[data-theme="dark"] .am-error{color:#E08663}
  .modal .agree{font-size:12px;color:#A9A498;margin-top:12px;line-height:1.8}
  .modal .agree a{text-decoration:underline;text-underline-offset:3px}

.name-lg{font-size:17px}

@media (forced-colors: active){
  body,.nav-wrap,.feature-card,.logo-tile,.modal,.auth-tabs{background:Canvas;color:CanvasText;border-color:CanvasText}
  :where(button,.modal input,.btn,.auth-tab){background:ButtonFace;color:ButtonText;border-color:ButtonText}
  .auth-tab.active{background:Highlight;color:HighlightText;border:2px solid HighlightText}
  :where(.hero-sub,.sec-sub,.models-note,.feature-card p,.modal .msub,.modal .agree){color:CanvasText}
  .modal input::placeholder{color:GrayText}
  :where(a,button):focus-visible{outline:2px solid Highlight!important;outline-offset:2px;box-shadow:none!important}
  :where(input,textarea,select):focus-visible{outline:none!important;box-shadow:none!important}
  .modal input:focus-visible{border-color:Highlight!important}
  .modal-overlay{background:Canvas}
  .am-error{color:CanvasText;border:2px solid CanvasText;padding:4px}
}

@media (prefers-contrast: more){
  :root{--muted:color-mix(in srgb,var(--ink) 82%,transparent);--ink-2:color-mix(in srgb,var(--ink) 88%,transparent);--line:color-mix(in srgb,var(--ink) 62%,transparent);--line-soft:color-mix(in srgb,var(--ink) 48%,transparent)}
  :where(.hero-sub,.sec-sub,.models-note,.feature-card p,.modal .msub,.modal .agree){color:var(--ink)}
  :where(.nav-wrap,.feature-card,.logo-tile,.modal,.auth-tabs,.modal input,.btn){border-color:currentColor}
  .auth-tab.active{border:2px solid currentColor;font-weight:700}
  :where(a,button):focus-visible{outline:2px solid #fff!important;outline-offset:2px;box-shadow:0 0 0 6px #0b3d91!important}
  :where(input,textarea,select):focus-visible{outline:none!important;box-shadow:none!important}
  .modal input:focus-visible{border-color:var(--accent)!important}
}