* { margin: 0; padding: 0; box-sizing: border-box; }
:root {
  --cream: #F5F1E8; --cream-dark: #EDE6D3; --clay: #D97757; --clay-dark: #B85A3F;
  --ink: #1A1915; --ink-soft: #4A4845; --gray: #9AA0A6; --gold: #E8B951;
  --code-bg: #1A1915; --code-text: #F5F1E8;
}
html { scroll-behavior: smooth; }
body {
  font-family: "Zen Kaku Gothic New", -apple-system, sans-serif;
  background: var(--cream); color: var(--ink);
  line-height: 1.85; font-weight: 500;
  font-feature-settings: "palt";
}
a { color: var(--clay); }
.container { max-width: 900px; margin: 0 auto; padding: 0 24px; }

/* Navigation */
.topnav {
  background: var(--ink); color: var(--cream);
  padding: 14px 24px;
  display: flex; justify-content: space-between; align-items: center;
  position: sticky; top: 0; z-index: 100;
}
.topnav a { color: var(--cream); text-decoration: none; font-family: "JetBrains Mono", monospace; font-size: 12px; letter-spacing: 2px; font-weight: 700; }
.topnav a:hover { color: var(--clay); }
.topnav .back::before { content: "← "; color: var(--clay); }

/* Category header */
header.cat-hero {
  padding: 72px 24px 56px;
  border-bottom: 3px solid var(--ink);
}
.cat-label {
  font-family: "JetBrains Mono", monospace;
  font-size: 13px; letter-spacing: 3px;
  color: var(--clay); font-weight: 700;
  margin-bottom: 20px;
}
h1.cat-title {
  font-size: clamp(38px, 5vw, 56px);
  font-weight: 900; line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}
h1.cat-title .hl { color: var(--clay); }
.cat-subtitle {
  font-size: 19px; color: var(--ink-soft);
  line-height: 1.85; font-weight: 500;
  max-width: 780px;
  margin-bottom: 28px;
}
.cat-counter {
  display: inline-flex; align-items: center; gap: 12px;
  background: var(--ink); color: var(--cream);
  padding: 12px 22px; border-radius: 8px;
  font-family: "JetBrains Mono", monospace;
  font-size: 14px; font-weight: 700; letter-spacing: 2px;
}
.cat-counter .k { color: var(--clay); font-size: 24px; }

/* Knock list overview */
.overview {
  padding: 48px 0;
  border-bottom: 2px dashed var(--ink);
}
.overview h2 {
  font-size: 22px; font-weight: 900;
  margin-bottom: 24px;
  font-family: "JetBrains Mono", monospace;
  letter-spacing: 2px; color: var(--clay);
}
.overview ol {
  list-style: none; counter-reset: k;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
  gap: 12px 24px;
}
.overview ol li {
  counter-increment: k;
  padding-left: 56px;
  position: relative;
  font-size: 15px;
  line-height: 1.7;
}
.overview ol li::before {
  content: "K" counter(k, decimal-leading-zero);
  position: absolute; left: 0; top: 2px;
  font-family: "JetBrains Mono", monospace;
  font-size: 13px; font-weight: 900;
  color: var(--clay);
  background: var(--cream-dark);
  padding: 2px 8px; border-radius: 4px;
  letter-spacing: 1px;
}
.overview ol li a { color: var(--ink); text-decoration: none; }
.overview ol li a:hover { color: var(--clay); text-decoration: underline; }

/* Knock article */
article.knock {
  padding: 72px 0;
  border-bottom: 3px solid var(--ink);
}
article.knock .knock-num {
  font-family: "JetBrains Mono", monospace;
  font-size: 14px; font-weight: 700;
  letter-spacing: 3px;
  color: var(--clay);
  margin-bottom: 12px;
}
article.knock h2.knock-title {
  font-size: clamp(26px, 3.2vw, 36px);
  font-weight: 900; line-height: 1.3;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}
article.knock .knock-lead {
  font-size: 17px;
  color: var(--ink-soft);
  line-height: 1.9;
  margin-bottom: 32px;
  padding: 20px 28px;
  background: var(--cream-dark);
  border-left: 6px solid var(--clay);
  border-radius: 0 8px 8px 0;
}

/* Section blocks inside a knock */
article.knock .block {
  margin: 28px 0;
}
article.knock .block-label {
  display: inline-block;
  font-family: "JetBrains Mono", monospace;
  font-size: 12px; letter-spacing: 2px;
  font-weight: 700;
  background: var(--ink); color: var(--cream);
  padding: 6px 14px;
  border-radius: 4px;
  margin-bottom: 12px;
}
article.knock .block-label.hl { background: var(--clay); }
article.knock h3 {
  font-size: 22px;
  font-weight: 900;
  margin-bottom: 12px;
  line-height: 1.4;
}
article.knock p {
  font-size: 15.5px;
  line-height: 1.95;
  margin-bottom: 14px;
  color: var(--ink);
}
article.knock p strong { color: var(--clay-dark); font-weight: 900; }
article.knock ul, article.knock ol {
  padding-left: 24px;
  margin-bottom: 16px;
  font-size: 15.5px;
  line-height: 1.95;
}
article.knock ul li, article.knock ol li {
  margin-bottom: 8px;
}
article.knock ul li::marker { color: var(--clay); }

/* Code blocks */
article.knock pre {
  background: var(--code-bg);
  color: var(--code-text);
  padding: 20px 24px;
  border-radius: 8px;
  overflow-x: auto;
  font-family: "JetBrains Mono", monospace;
  font-size: 13px;
  line-height: 1.7;
  margin: 16px 0 20px;
}
article.knock pre .c { color: #9AA0A6; }
article.knock pre .k { color: #D97757; }
article.knock pre .v { color: #E8D4A8; }
article.knock code {
  background: var(--cream-dark);
  padding: 2px 8px;
  border-radius: 4px;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.92em;
  color: var(--clay-dark);
}

/* Experience / Ren quote */
article.knock .ren-note {
  background: #FFF;
  border: 2px solid var(--ink);
  border-radius: 8px;
  padding: 24px 28px;
  margin: 20px 0;
  box-shadow: 4px 4px 0 var(--clay);
  position: relative;
}
article.knock .ren-note::before {
  content: "れんの実体験";
  position: absolute; top: -12px; left: 20px;
  background: var(--clay); color: var(--cream);
  padding: 4px 12px;
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; font-weight: 700;
  letter-spacing: 1px;
  border-radius: 4px;
}
article.knock .ren-note p {
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--ink-soft);
}

/* Template / copy block */
article.knock .template {
  background: var(--cream-dark);
  border: 2px dashed var(--clay);
  padding: 20px 24px;
  border-radius: 8px;
  margin: 16px 0;
}
article.knock .template-label {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; font-weight: 700;
  letter-spacing: 2px;
  color: var(--clay); margin-bottom: 10px;
}

/* Pitfall callout */
article.knock .pitfall {
  background: #FFF9EA;
  border-left: 4px solid var(--gold);
  padding: 18px 24px;
  border-radius: 0 8px 8px 0;
  margin: 16px 0;
}
article.knock .pitfall h4 {
  font-size: 14px; font-weight: 900;
  color: var(--clay-dark);
  margin-bottom: 8px;
  font-family: "JetBrains Mono", monospace;
  letter-spacing: 1px;
}
article.knock .pitfall ul { padding-left: 20px; margin-bottom: 0; font-size: 14px; }
article.knock .pitfall li { margin-bottom: 4px; }

/* Next link */
article.knock .next {
  margin-top: 40px;
  padding-top: 28px;
  border-top: 2px dashed var(--ink);
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 12px;
  font-family: "JetBrains Mono", monospace;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--ink-soft);
}
article.knock .next a {
  color: var(--clay);
  text-decoration: none;
  border-bottom: 2px solid var(--clay);
  padding-bottom: 2px;
}
article.knock .next a:hover { color: var(--clay-dark); border-color: var(--clay-dark); }

/* CTA at bottom of category */
.cat-cta {
  background: var(--ink); color: var(--cream);
  padding: 72px 24px;
  text-align: center;
}
.cat-cta h2 {
  font-size: clamp(26px, 3.5vw, 36px);
  font-weight: 900;
  margin-bottom: 16px;
  line-height: 1.3;
}
.cat-cta h2 .hl { color: var(--clay); }
.cat-cta p {
  font-size: 16px;
  color: var(--cream-dark);
  margin-bottom: 32px;
}
.cat-cta a {
  display: inline-block;
  background: var(--clay); color: var(--cream);
  padding: 16px 40px;
  border-radius: 999px;
  font-weight: 900;
  text-decoration: none;
  font-size: 16px;
  border: 3px solid var(--cream);
  box-shadow: 5px 5px 0 var(--clay-dark);
  transition: all 0.15s;
}
.cat-cta a:hover {
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 var(--clay-dark);
}

footer {
  padding: 48px 24px;
  text-align: center;
  font-size: 12px;
  color: var(--gray);
  font-family: "JetBrains Mono", monospace;
  border-top: 3px solid var(--ink);
  background: var(--cream);
}
footer .copy { letter-spacing: 2px; margin-top: 12px; }

@media (max-width: 640px) {
  header.cat-hero { padding: 48px 24px 40px; }
  article.knock { padding: 48px 0; }
  article.knock pre { padding: 14px 16px; font-size: 12px; }
  .overview ol { grid-template-columns: 1fr; }
}