:root{
    --ink:#122436; --ink-soft:#3c5163;
    --paper:#eef2f2; --paper-card:#ffffff; --line:#c9d3d2;
    --delft:#1e3a5f; --delft-deep:#0f2340;
    --gold:#c98a1f; --wine:#8c2a3a; --teal:#1f6f78;
    --radius:3px;
  }
  *{box-sizing:border-box;}
  body{margin:0;background:var(--paper);color:var(--ink);font-family:system-ui,"Microsoft YaHei",sans-serif;line-height:1.55;}
  h1,h2,.serif{font-family:Georgia,"Microsoft YaHei",serif;}
  a{color:inherit;}

  .site-nav{background:var(--delft-deep);border-bottom:1px solid #0a1c30;}
  .site-nav-inner{
    max-width:1080px;margin:0 auto;padding:14px 24px;
    display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:10px;
  }
  .brand{font-family:Georgia,"Microsoft YaHei",serif;font-size:18px;font-weight:700;color:#fff;text-decoration:none;letter-spacing:-0.01em;}
  .site-nav nav{display:flex;gap:4px;flex-wrap:wrap;}
  .site-nav nav a{
    color:#cdd9e3;text-decoration:none;font-size:13.5px;padding:7px 12px;border-radius:var(--radius);
  }
  .site-nav nav a:hover{background:rgba(255,255,255,0.08);color:#fff;}

  .hero{max-width:1080px;margin:0 auto;padding:56px 24px 40px;border-bottom:1px solid var(--line);}
  .hero h1{font-size:clamp(30px,4.5vw,44px);font-weight:700;margin:0 0 14px;color:var(--delft-deep);letter-spacing:-0.01em;max-width:680px;}
  .hero p{max-width:600px;color:var(--ink-soft);font-size:16px;margin:0;}

  .grid-wrap{max-width:1080px;margin:0 auto;padding:40px 24px 80px;}
  .grid-wrap h2{font-size:14px;text-transform:none;color:var(--ink-soft);font-weight:600;margin:0 0 20px;letter-spacing:0.02em;}

  .tool-grid{display:grid;grid-template-columns:repeat(auto-fit, minmax(260px, 1fr));gap:20px;}
  .tool-card{
    background:var(--paper-card);border:1px solid var(--line);border-radius:var(--radius);
    padding:24px 22px;text-decoration:none;color:var(--ink);
    display:flex;flex-direction:column;gap:10px;
    border-top:3px solid var(--line);
    transition:border-color 0.15s ease;
  }
  .tool-card:hover{border-top-color:var(--delft);}
  .tool-card .tag{
    font-size:11px;font-weight:600;letter-spacing:0.02em;
    display:inline-block;padding:3px 9px;border-radius:2px;width:fit-content;
  }
  .tool-card.c1 .tag{background:#f6ecda;color:#8a5f10;}
  .tool-card.c2 .tag{background:#e3f1f1;color:var(--teal);}
  .tool-card.c3 .tag{background:#f7ecec;color:var(--wine);}
  .tool-card.c4 .tag{background:#eaf0f6;color:var(--delft-deep);}
  .tool-card.c5 .tag{background:#f2e9f2;color:#6b3f6b;}
  .tool-card h3{font-size:18px;margin:0;font-family:Georgia,"Microsoft YaHei",serif;color:var(--delft-deep);}
  .tool-card .desc{font-size:13.5px;color:var(--ink-soft);flex:1;}
  .tool-card .cta{font-size:13px;font-weight:600;color:var(--delft);}

  footer{border-top:1px solid var(--line);padding:24px;text-align:center;font-size:12.5px;color:var(--ink-soft);}