*{box-sizing:border-box}



body{

margin:0;

font-family:Arial,sans-serif;

color:#222;

background:#f7f8fa;

line-height:1.7

}



a{text-decoration:none;color:inherit}



header{

background:#0b1f3a;

color:#fff;

padding:16px 0

}



.header-inner{

max-width:1100px;

margin:auto;

padding:0 20px;

display:flex;

justify-content:space-between;

align-items:center

}



.brand{

font-size:22px;

font-weight:700

}



nav{

display:flex;

gap:20px;

flex-wrap:wrap

}



nav a{

color:#fff;

font-size:15px

}



main{

max-width:900px;

margin:40px auto;

padding:0 20px

}



article{

background:#fff;

padding:40px;

border-radius:12px;

box-shadow:0 2px 10px rgba(0,0,0,.06)

}



h1,h2{

color:#0b1f3a;

line-height:1.3

}



h1{

font-size:34px;

margin-top:0

}



h2{

font-size:25px;

margin-top:34px

}



p,li{

font-size:17px

}



.intro{

font-size:19px;

color:#444

}



.box{

background:#eef5ff;

border-left:4px solid #0b63ce;

padding:18px;

margin:25px 0;

border-radius:6px

}



.example{

background:#f8f9fb;

border:1px solid #e2e6ea;

padding:18px;

border-radius:8px;

margin:22px 0

}



.related{

margin-top:40px;

padding-top:20px;

border-top:1px solid #ddd

}



.related a{

color:#0b63ce

}



.disclaimer{

margin-top:35px;

background:#fff8e8;

border:1px solid #f0dfad;

padding:18px;

border-radius:8px;

color:#5c4b1d

}



footer{

text-align:center;

padding:25px 20px 40px;

color:#666;

font-size:14px

}



@media(max-width:600px){



.header-inner{

flex-direction:column;

align-items:flex-start;

gap:10px

}



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-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;

}