*{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 a{margin-left:18px;color:#fff;font-size:15px}



.hero{

background:#102a4c;

color:#fff;

padding:55px 20px;

text-align:center

}

.hero h1{

max-width:900px;

margin:0 auto 15px;

font-size:38px;

line-height:1.25

}

.hero p{

max-width:760px;

margin:auto;

font-size:18px;

color:#dbe7f5

}



.container{

max-width:900px;

margin:35px auto;

padding:0 20px

}



article{

background:#fff;

padding:35px;

border-radius:12px;

box-shadow:0 2px 12px rgba(0,0,0,.06)

}



h2{

color:#102a4c;

margin-top:32px;

font-size:27px

}



h3{

color:#173b67;

margin-top:24px;

font-size:21px

}



p,li{font-size:17px}

ul,ol{padding-left:22px}



.info{

background:#eef5ff;

border-left:4px solid #2563eb;

padding:18px;

margin:24px 0;

border-radius:6px

}



.related{

background:#f3f6fa;

padding:22px;

border-radius:10px;

margin-top:35px

}

.related ul{margin-bottom:0}



footer{

margin-top:40px;

background:#0b1f3a;

color:#dbe7f5;

padding:28px 20px;

text-align:center;

font-size:14px

}

footer a{color:#fff;margin:0 8px}



@media(max-width:600px){

.header-inner{flex-direction:column;gap:10px}

nav a{margin:0 7px;font-size:14px}

.hero{padding:40px 18px}

.hero h1{font-size:28px}

article{padding:24px 18px}

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;

}