:root{--bg:#f6f8fb;--card:#fff;--text:#172033;--muted:#5f6b7a;--primary:#0b63ce;--border:#e3e8ef}

*{box-sizing:border-box}

body{margin:0;font-family:Arial,Helvetica,sans-serif;background:var(--bg);color:var(--text);line-height:1.75}

header{background:#fff;border-bottom:1px solid var(--border)}

.header-inner{max-width:1000px;margin:auto;padding:18px 20px}

.brand{color:var(--text);text-decoration:none;font-weight:700;font-size:20px}

nav{margin-top:10px;display:flex;flex-wrap:wrap;gap:14px}

nav a{color:var(--primary);text-decoration:none;font-size:14px}

main{max-width:900px;margin:35px auto;padding:0 20px}

article{background:var(--card);border:1px solid var(--border);border-radius:14px;padding:30px}

h1,h2{line-height:1.3;color:#101828}

h1{font-size:34px;margin-top:0}

h2{margin-top:35px;font-size:25px}

p,li{font-size:17px}

.intro{font-size:19px;color:#3f4b5b}

.box{background:#f2f7ff;border-left:4px solid var(--primary);padding:18px;border-radius:8px;margin:24px 0}

.example{background:#fafafa;border:1px solid var(--border);padding:18px;border-radius:10px;margin:20px 0}

table{width:100%;border-collapse:collapse;margin:20px 0}

th,td{border:1px solid var(--border);padding:12px;text-align:left;vertical-align:top}

th{background:#f2f7ff}

.related{margin-top:35px;padding-top:20px;border-top:1px solid var(--border)}

.related ul{padding-left:20px}

.related a{color:var(--primary);text-decoration:none}

.disclaimer{margin-top:35px;background:#fff8e8;border:1px solid #f0dfad;padding:18px;border-radius:10px;color:#5c4b1d}

footer{text-align:center;padding:25px 20px 40px;color:var(--muted);font-size:14px}

@media(max-width:600px){

main{margin:20px auto;padding:0 12px}

article{padding:22px 18px}

h1{font-size:28px}

h2{font-size:23px}

p,li{font-size:16px}

table{font-size:14px}

th,td{padding:9px}

}

.table-of-contents{

  margin:24px 0;

  border:1px solid #e1e6ee;

  border-radius:12px;

  background:#f8fafc;

  overflow:hidden;

}



.toc-toggle{

  width:100%;

  border:0;

  background:#071b35;

  color:#fff;

  padding:16px 18px;

  font-size:16px;

  font-weight:700;

  display:flex;

  justify-content:space-between;

  align-items:center;

  cursor:pointer;

}



.toc-arrow{

  font-size:18px;

  line-height:1;

}



.toc-content{

  display:none;

  padding:14px 22px;

}



.table-of-contents.open .toc-content{

  display:block;

}



.toc-content ul{

  margin:0;

  padding-left:18px;

}



.toc-content li{

  margin:10px 0;

}



.toc-content a{

  color:#0d3b66;

  text-decoration:none;

  font-weight:600;

}



.toc-content a:hover{

  text-decoration:underline;

}



@media(max-width:600px){

  .toc-toggle{

    padding:15px;

  }



  .toc-content{

    padding:12px 18px;

  }

}

.author-box{

    margin:30px 0;

    padding:20px;

    border:1px solid #ddd;

    border-radius:10px;

    background:#f8f9fa;

}

.author-box strong{

    display:block;

    font-size:18px;

    margin-bottom:5px;

}

.author-box span{

    display:block;

    font-size:14px;

    margin-bottom:12px;

    color:#555;

}

.author-box p{

    margin:0;

    line-height:1.6;

}