/* ===== Base ===== */
:root{
  --bg: #0b0b10;
  --bg-alt: #14141c;
  --border: #262632;
  --text: #e9e9f0;
  --text-dim: #a8a8b8;
  --red: #d81b45;
  --red-dark: #a9143a;
  --blue: #2f4f7a;
  --header-h: 84px;
}

*,*::before,*::after{box-sizing:border-box}

html{scroll-behavior:smooth}

body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family: "Segoe UI", Arial, Helvetica, sans-serif;
  line-height:1.6;
}

img{max-width:100%;display:block}

a{color:var(--red)}
a:hover{color:#fff}

h1,h2,h3{line-height:1.25;color:#fff}

.container{
  max-width:1180px;
  margin:0 auto;
  padding:0 20px;
}

/* ===== Header ===== */
.site-header{
  position:sticky;
  top:0;
  z-index:100;
  background:rgba(11,11,16,0.97);
  border-bottom:1px solid var(--border);
  height:var(--header-h);
}

.header-inner{
  max-width:1180px;
  margin:0 auto;
  padding:0 16px;
  height:100%;
  display:flex;
  align-items:center;
  gap:16px;
}

.logo-link{
  flex:0 0 auto;
  display:flex;
  align-items:center;
}

.logo-link img{
  height:64px;
  width:64px;
  object-fit:contain;
  border-radius:8px;
}

.main-nav{
  flex:1 1 auto;
}

.main-nav ul{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  gap:28px;
}

.main-nav a{
  color:var(--text);
  text-decoration:none;
  font-size:15px;
  font-weight:600;
}

.main-nav a:hover,
.main-nav a[aria-current="page"]{
  color:var(--red)
}

.header-actions{
  flex:0 0 auto;
  display:flex;
  gap:10px;
}

.btn{
  display:inline-block;
  text-decoration:none;
  font-weight:700;
  border-radius:8px;
  padding:10px 18px;
  font-size:14px;
  white-space:nowrap;
  border:1px solid transparent;
  cursor:pointer;
}

.btn-ghost{
  color:var(--text);
  border-color:var(--border);
  background:transparent;
}
.btn-ghost:hover{border-color:var(--red);color:#fff}

.btn-solid{
  background:var(--red);
  color:#fff;
}
.btn-solid:hover{background:var(--red-dark);color:#fff}

/* burger control (checkbox hack, no JS) */
.nav-toggle{position:absolute;opacity:0;pointer-events:none}

.burger-label{
  display:none;
  flex:0 0 auto;
  width:40px;
  height:40px;
  border-radius:8px;
  border:1px solid var(--border);
  align-items:center;
  justify-content:center;
  cursor:pointer;
}

.burger-label span,
.burger-label span::before,
.burger-label span::after{
  content:"";
  display:block;
  width:20px;
  height:2px;
  background:#fff;
  position:relative;
}
.burger-label span::before{position:absolute;top:-6px}
.burger-label span::after{position:absolute;top:6px}

/* ===== Breadcrumbs ===== */
.breadcrumbs{
  background:var(--bg-alt);
  border-bottom:1px solid var(--border);
}
.breadcrumbs ol{
  list-style:none;
  margin:0;
  padding:10px 0;
  display:flex;
  flex-wrap:wrap;
  gap:6px;
  font-size:13px;
  color:var(--text-dim);
}
.breadcrumbs li:not(:last-child)::after{
  content:"/";
  margin-left:6px;
  color:var(--text-dim);
}
.breadcrumbs a{color:var(--text-dim);text-decoration:none}
.breadcrumbs a:hover{color:var(--red)}
.breadcrumbs li[aria-current="page"]{color:var(--text)}

/* ===== Hero ===== */
.hero{
  position:relative;
  background-image:url("../img/banner.jpg");
  background-size:cover;
  background-position:center;
  min-height:360px;
  display:flex;
  align-items:center;
}

.hero-inner{
  max-width:1180px;
  margin:0 auto;
  padding:40px 20px;
  width:100%;
}

.hero-content{
  max-width:480px;
}

.hero-content h1{
  font-size:34px;
  margin:0 0 14px;
  color:#fff;
  text-shadow:0 2px 12px rgba(0,0,0,0.6);
}

.hero-content p{
  color:#d6d6e0;
  margin:0 0 22px;
  text-shadow:0 2px 10px rgba(0,0,0,0.6);
}

.hero-content .btn{
  font-size:16px;
  padding:14px 28px;
}

/* ===== Layout wrapper ===== */
.page-content{
  max-width:820px;
  margin:0 auto;
  padding:40px 20px 60px;
}

.page-content h2{
  font-size:24px;
  margin-top:44px;
  border-bottom:2px solid var(--red);
  padding-bottom:8px;
  display:inline-block;
}

.page-content section:first-of-type h2{margin-top:0}

.page-content table{
  width:100%;
  border-collapse:collapse;
  margin:18px 0;
}
.page-content th,
.page-content td{
  border:1px solid var(--border);
  padding:10px 12px;
  text-align:left;
  font-size:14px;
}
.page-content th{background:var(--bg-alt);color:#fff}

.page-content details{
  background:var(--bg-alt);
  border:1px solid var(--border);
  border-radius:8px;
  padding:14px 16px;
  margin-bottom:10px;
}
.page-content details summary{cursor:pointer;font-weight:700}
.page-content details p{margin:10px 0 0}

.author-box{
  max-width:820px;
  margin:0 auto 40px;
  padding:18px 20px;
  border-top:1px solid var(--border);
  color:var(--text-dim);
  font-size:14px;
}

/* ===== TOC accordion ===== */
.toc-accordion{
  max-width:820px;
  margin:30px auto 0;
  padding:0 20px;
}
.toc-accordion details{
  background:var(--bg-alt);
  border:1px solid var(--border);
  border-radius:8px;
  padding:16px 18px;
}
.toc-accordion summary{
  cursor:pointer;
  font-weight:700;
  color:#fff;
  list-style:none;
}
.toc-accordion summary::-webkit-details-marker{display:none}
.toc-accordion summary::after{
  content:"+";
  float:right;
  color:var(--red);
  font-size:18px;
}
.toc-accordion details[open] summary::after{content:"−"}
.toc-accordion ol{
  margin:14px 0 0;
  padding-left:20px;
}
.toc-accordion li{margin-bottom:6px}
.toc-accordion a{text-decoration:none}
.toc-accordion a:hover{text-decoration:underline}

/* ===== Footer ===== */
.site-footer{
  background:var(--bg-alt);
  border-top:1px solid var(--border);
  padding:36px 0 20px;
  margin-top:40px;
}
.footer-inner{
  max-width:1180px;
  margin:0 auto;
  padding:0 20px;
  display:flex;
  flex-wrap:wrap;
  justify-content:space-between;
  gap:24px;
}
.footer-nav ul{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  gap:20px;
  flex-wrap:wrap;
}
.footer-nav a{color:var(--text-dim);text-decoration:none;font-size:14px}
.footer-nav a:hover{color:var(--red)}
.footer-disclaimer{
  max-width:1180px;
  margin:20px auto 0;
  padding:16px 20px 0;
  border-top:1px solid var(--border);
  font-size:12px;
  color:var(--text-dim);
}
.footer-copy{font-size:13px;color:var(--text-dim)}

/* ===== Redirect page ===== */
.redirect{
  min-height:100vh;
  display:flex;
  align-items:center;
  justify-content:center;
  padding:20px;
}
.redirect__box{
  text-align:center;
  max-width:360px;
}
.redirect__box img{
  margin:0 auto 20px;
  border-radius:16px;
}
.redirect__box p{
  color:var(--text-dim);
  margin-bottom:20px;
}

/* ===== Mobile ===== */
@media (max-width:820px){
  .header-inner{gap:10px;padding:0 12px}
  .logo-link img{height:50px;width:50px}

  .burger-label{display:flex;order:3}

  .main-nav{
    order:4;
    flex-basis:100%;
  }
  .main-nav ul{
    display:none;
    flex-direction:column;
    gap:0;
    position:absolute;
    left:0;right:0;
    top:var(--header-h);
    background:var(--bg-alt);
    border-bottom:1px solid var(--border);
    padding:8px 12px;
  }
  .main-nav ul li{border-top:1px solid var(--border)}
  .main-nav ul li:first-child{border-top:none}
  .main-nav a{display:block;padding:12px 4px}

  .nav-toggle:checked ~ .main-nav ul{display:flex}

  .header-actions{order:2;gap:6px}
  .header-actions .btn{padding:8px 10px;font-size:12px}

  .hero{min-height:280px}
  .hero-content{max-width:100%}
  .hero-content h1{font-size:24px}
  .hero-content p{font-size:14px}

  .footer-inner{flex-direction:column}
}

@media (max-width:420px){
  .logo-link img{height:42px;width:42px}
  .header-actions .btn{padding:7px 8px;font-size:11px}
  .main-nav a{font-size:14px}
}