:root{
    --paper:#EFEDE6;
    --paper-raised:#F6F4EE;
    --ink:#1C2B3A;
    --ink-soft:#4A5A68;
    --rule:#CFC7B4;
    --accent:#E3A324;
    --accent-ink:#5A3E08;
    --teal:#2F6F63;
    --max:720px;
  }
  *{box-sizing:border-box;}
  html{scroll-behavior:smooth;}
  body{
    margin:0;
    background:var(--paper);
    color:var(--ink);
    font-family:'IBM Plex Sans', sans-serif;
    line-height:1.6;
  }
  a{color:var(--teal);}
  .wrap{max-width:1080px;margin:0 auto;padding:0 28px;}
  .prose{max-width:var(--max);}

  body::before{
    content:"";
    position:fixed;
    top:0; bottom:0; left:56px;
    width:1px;
    background:var(--rule);
    z-index:0;
  }
  @media (max-width:760px){ body::before{ left:24px; } }

  header{
    padding:22px 0 16px;
    border-bottom:1px solid var(--rule);
    position:sticky; top:0;
    background:var(--paper);
    z-index:10;
  }
  .nav-row{
    display:flex; justify-content:space-between; align-items:baseline;
    flex-wrap:wrap; gap:14px;
  }
  .brand{
    font-family:'Fraunces', serif;
    font-weight:600;
    font-size:1.25rem;
    letter-spacing:-0.01em;
  }
  nav{display:flex; align-items:center; flex-wrap:wrap; gap:0;}
  nav a{
    font-family:'IBM Plex Mono', monospace;
    font-size:0.82rem;
    text-decoration:none;
    color:var(--ink-soft);
    margin-left:20px;
  }
  nav a:first-child{margin-left:0;}
  nav a:hover{color:var(--teal);}
  nav a.cta{
    margin-left:20px;
    background:var(--ink); color:var(--paper);
    padding:7px 14px; border-radius:2px;
  }
  nav a.cta:hover{background:var(--teal); color:var(--paper);}

  .hero{padding:56px 0 44px; border-bottom:1px solid var(--rule);}
  .hero .stamp{
    font-family:'IBM Plex Mono', monospace;
    font-size:0.82rem;
    color:var(--accent-ink);
    background:linear-gradient(transparent 60%, var(--accent) 60%);
    display:inline; padding:0 2px;
  }
  .hero h1{
    font-family:'Fraunces', serif;
    font-weight:500; font-style:italic;
    font-size:clamp(1.9rem, 4vw, 2.9rem);
    line-height:1.2; margin:16px 0 18px; max-width:880px;
  }
  .hero p.sub{max-width:var(--max); font-size:1.05rem; color:var(--ink-soft);}

  /* Category filter bar */
  .cat-bar{
    display:flex; gap:8px; flex-wrap:wrap;
    padding:24px 0; border-bottom:1px solid var(--rule);
    font-family:'IBM Plex Mono', monospace; font-size:0.8rem;
  }
  .cat-bar button{
    border:1px solid var(--rule); background:var(--paper-raised);
    color:var(--ink-soft); padding:7px 14px; border-radius:2px;
    cursor:pointer;
  }
  .cat-bar button.active{
    background:var(--ink); color:var(--paper); border-color:var(--ink);
  }
  .cat-bar button:hover{border-color:var(--ink);}

  section{padding:48px 0; border-bottom:1px solid var(--rule);}
  .section-head{
    display:flex; justify-content:space-between; align-items:baseline;
    margin-bottom:30px; gap:16px; flex-wrap:wrap;
  }
  .section-head h2{font-family:'Fraunces', serif; font-weight:500; font-size:1.6rem; margin:0;}
  .section-head .meta{font-family:'IBM Plex Mono', monospace; font-size:0.8rem; color:var(--ink-soft);}

  .entry{
    display:grid; grid-template-columns:130px 1fr; gap:26px;
    padding:24px 0; border-top:1px solid var(--rule);
  }
  .entry:first-of-type{border-top:none;}
  .entry .meta-col{font-family:'IBM Plex Mono', monospace; font-size:0.78rem; color:var(--ink-soft);}
  .entry .meta-col .author{display:block; margin-top:6px; color:var(--teal);}
  .entry h3{font-family:'Fraunces', serif; font-weight:600; font-size:1.22rem; margin:0 0 8px;}
  .entry h3 a{color:var(--ink); text-decoration:none;}
  .entry h3 a:hover{color:var(--teal);}
  .entry p{margin:0 0 10px; color:var(--ink-soft); max-width:560px;}
  .tag{
    font-family:'IBM Plex Mono', monospace; font-size:0.72rem;
    color:var(--accent-ink); background:var(--accent);
    padding:2px 8px; border-radius:2px;
  }
  @media (max-width:600px){ .entry{grid-template-columns:1fr; gap:8px;} }

  .about-grid{display:grid; grid-template-columns:1fr 1fr; gap:44px;}
  @media (max-width:760px){ .about-grid{grid-template-columns:1fr;} }
  .about-grid h2{font-family:'Fraunces', serif; font-weight:500; font-size:1.6rem; margin-top:0;}
  .credentials{font-family:'IBM Plex Mono', monospace; font-size:0.84rem; color:var(--ink-soft); line-height:2;}
  .credentials strong{color:var(--ink); font-weight:500;}

  .two-col{display:grid; grid-template-columns:1fr 1fr; gap:24px;}
  @media (max-width:760px){ .two-col{grid-template-columns:1fr;} }
  .panel{
    background:var(--paper-raised); border:1px solid var(--rule); padding:30px;
  }
  .panel .eyebrow{font-family:'IBM Plex Mono', monospace; font-size:0.76rem; color:var(--teal); margin-bottom:10px;}
  .panel h3{font-family:'Fraunces', serif; font-style:italic; font-weight:500; font-size:1.4rem; margin:0 0 12px;}
  .panel p{color:var(--ink-soft); margin-bottom:20px;}

  .signup{display:flex; max-width:420px; border:1px solid var(--ink);}
  .signup input{flex:1; border:none; background:transparent; padding:11px 14px; font-family:'IBM Plex Sans', sans-serif; font-size:0.92rem; color:var(--ink); outline:none;}
  .signup button{border:none; background:var(--ink); color:var(--paper); padding:11px 18px; font-family:'IBM Plex Mono', monospace; font-size:0.8rem; cursor:pointer;}
  .signup button:hover{background:var(--teal);}

  .btn{
    display:inline-block; background:var(--ink); color:var(--paper);
    text-decoration:none; padding:11px 20px; font-family:'IBM Plex Mono', monospace;
    font-size:0.8rem; border-radius:2px;
  }
  .btn:hover{background:var(--teal); color:var(--paper);}

  footer{
    padding:32px 0 52px; font-family:'IBM Plex Mono', monospace; font-size:0.8rem;
    color:var(--ink-soft); display:flex; justify-content:space-between; flex-wrap:wrap; gap:12px;
  }
  footer a{color:var(--ink-soft); margin-right:16px;}
  footer a:hover{color:var(--teal);}

/* Article page styles */
.article-header{padding:36px 0 20px;}
.back-link{
  font-family:'IBM Plex Mono', monospace; font-size:0.8rem;
  color:var(--ink-soft); text-decoration:none; display:inline-block; margin-bottom:22px;
}
.back-link:hover{color:var(--teal);}
.article-meta{
  font-family:'IBM Plex Mono', monospace; font-size:0.8rem; color:var(--ink-soft);
  display:flex; gap:16px; flex-wrap:wrap; margin-bottom:14px; align-items:center;
}
.article-meta .tag{
  font-family:'IBM Plex Mono', monospace; font-size:0.72rem;
  color:var(--accent-ink); background:var(--accent); padding:2px 8px; border-radius:2px;
}
.article-header h1{
  font-family:'Fraunces', serif; font-weight:500; font-style:italic;
  font-size:clamp(1.8rem, 4vw, 2.6rem); line-height:1.25; margin:10px 0 0; max-width:760px;
}
.article-body{max-width:760px; padding:8px 0 60px;}
.article-body h2{
  font-family:'Fraunces', serif; font-weight:600; font-size:1.5rem;
  margin:44px 0 18px; padding-top:6px;
}
.article-body h3{
  font-family:'Fraunces', serif; font-weight:600; font-style:italic; font-size:1.18rem;
  margin:30px 0 14px;
}
.article-body h4{
  font-family:'IBM Plex Mono', monospace; font-weight:500; font-size:0.85rem;
  color:var(--teal); text-transform:uppercase; letter-spacing:0.03em; margin:26px 0 10px;
}
.article-body p{margin:0 0 18px; color:var(--ink-soft); font-size:1rem;}
.article-body strong{color:var(--ink); font-weight:600;}
.article-body ul, .article-body ol{margin:0 0 18px; padding-left:22px; color:var(--ink-soft);}
.article-body li{margin-bottom:6px;}
.article-body hr{border:none; border-top:1px solid var(--rule); margin:38px 0;}
.article-body blockquote{
  margin:20px 0; padding:14px 20px; border-left:3px solid var(--accent);
  background:var(--paper-raised); font-style:italic; color:var(--ink);
}
.article-body table{
  width:100%; border-collapse:collapse; margin:20px 0 26px;
  font-size:0.92rem;
}
.article-body th, .article-body td{
  border:1px solid var(--rule); padding:8px 12px; text-align:left;
}
.article-body th{
  font-family:'IBM Plex Mono', monospace; font-size:0.78rem;
  background:var(--paper-raised); color:var(--ink);
}
.article-body td{color:var(--ink-soft);}
.article-body pre{
  background:#1C2B3A; color:#E8E4D9; padding:22px 20px 18px; border-radius:4px;
  overflow-x:auto; margin:0 0 24px; font-size:0.86rem; line-height:1.6;
  position:relative;
}
.article-body code{
  font-family:'IBM Plex Mono', monospace;
}
.article-body p code, .article-body li code{
  background:var(--paper-raised); color:var(--accent-ink);
  padding:1px 6px; border-radius:2px; font-size:0.88em; border:1px solid var(--rule);
}
.coming-soon{
  padding:22px 0; border-top:1px solid var(--rule);
  font-family:'IBM Plex Mono', monospace; font-size:0.85rem; color:var(--ink-soft);
  display:flex; justify-content:space-between; align-items:center; gap:12px; flex-wrap:wrap;
}
.coming-soon .label{color:var(--ink); font-family:'Fraunces', serif; font-style:italic; font-size:1.05rem;}

/* Code Copy Button */
.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  background: rgba(239, 237, 230, 0.12);
  color: #CFC7B4;
  border: 1px solid rgba(207, 199, 180, 0.25);
  border-radius: 3px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.72rem;
  padding: 3px 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  line-height: 1.4;
}
.copy-btn:hover {
  background: rgba(239, 237, 230, 0.22);
  color: #FFFFFF;
  border-color: rgba(207, 199, 180, 0.45);
}
.copy-btn.copied {
  background: var(--teal);
  color: #FFFFFF;
  border-color: var(--teal);
}

/* Syntax Highlighting Tokens (Harmonized with Ink & Paper palette) */
.token.comment, .token.prolog, .token.doctype, .token.cdata {
  color: #798E9C;
  font-style: italic;
}
.token.punctuation {
  color: #B5C2CC;
}
.token.namespace {
  opacity: .7;
}
.token.property, .token.tag, .token.constant, .token.symbol, .token.deleted {
  color: #E5A84B;
}
.token.boolean, .token.number {
  color: #E58A67;
}
.token.selector, .token.attr-name, .token.string, .token.char, .token.builtin, .token.inserted {
  color: #8CC084;
}
.token.operator, .token.entity, .token.url, .language-css .token.string, .style .token.string {
  color: #7BB3CD;
}
.token.atrule, .token.attr-value, .token.keyword {
  color: #6EB2D4;
  font-weight: 500;
}
.token.function, .token.class-name {
  color: #F0C674;
}
.token.regex, .token.important, .token.variable {
  color: #E5A84B;
}
.token.important, .token.bold {
  font-weight: bold;
}
.token.italic {
  font-style: italic;
}

/* Collapsible Practice Question Answers */
details.answers-box {
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 14px 18px;
  margin: 22px 0 28px;
  transition: background 0.2s ease;
}
details.answers-box summary {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--teal);
  cursor: pointer;
  user-select: none;
  display: flex;
  align-items: center;
  gap: 8px;
}
details.answers-box summary:hover {
  color: var(--ink);
}
details.answers-box[open] summary {
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px dashed var(--rule);
}
details.answers-box ol {
  margin-bottom: 0;
  padding-left: 20px;
}

/* Next / Prev Post Navigation */
.post-nav {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--rule);
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.post-nav-card {
  flex: 1;
  min-width: 240px;
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  padding: 16px 20px;
  text-decoration: none;
  border-radius: 3px;
  transition: border-color 0.2s, transform 0.2s;
}
.post-nav-card:hover {
  border-color: var(--teal);
  transform: translateY(-1px);
}
.post-nav-card .nav-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.72rem;
  color: var(--teal);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 6px;
  display: block;
}
.post-nav-card .nav-title {
  font-family: 'Fraunces', serif;
  font-size: 1.05rem;
  color: var(--ink);
  font-weight: 500;
  margin: 0;
}