:root{--bg:#F7F4EC;--panel:#fff;--stroke:#E6E0D2;--hi:#2B2A26;--lo:#7A766C;--leaf:#5FA86A;--leafdeep:#3F8A4C}
@media (prefers-color-scheme:dark){:root{--bg:#15181A;--panel:#1F2427;--stroke:#2F363A;--hi:#F1EEE6;--lo:#9AA09C}}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--hi);font:16px/1.55 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif}
.wrap{max-width:720px;margin:0 auto;padding:0 20px}
.site-header{border-bottom:1px solid var(--stroke)}.site-header .wrap{display:flex;align-items:center;justify-content:space-between;height:60px}
.brand{font-weight:800;color:var(--hi);text-decoration:none;font-size:18px}.site-nav a{color:var(--lo);text-decoration:none;margin-left:18px;font-weight:600}
main{padding:32px 20px 64px;max-width:720px;margin:0 auto}h1{font-size:32px;margin:0 0 6px}h2{font-size:20px;margin:28px 0 8px}
.lead{font-size:18px;color:var(--lo)}.effective{color:var(--lo);font-size:14px}a{color:var(--leafdeep)}
.card{background:var(--panel);border:1px solid var(--stroke);border-radius:18px;padding:20px;margin:16px 0}
.btn{display:inline-block;background:var(--leaf);color:#fff;font-weight:800;padding:12px 20px;border-radius:14px;text-decoration:none}
footer{color:var(--lo);font-size:13px;text-align:center;padding:24px}