/* site.css — homepage / topic index for teach.cloudguard.rocks.
   Matches the k8s lesson.css aesthetic: Tufte-inspired serif, generous
   margins, restrained palette. Each topic card carries its own accent. */

:root {
  --ink:        #1a1a1a;
  --ink-soft:   #5b5b5b;
  --paper:      #fdfdfb;
  --rule:       #e4e2da;
  --accent:     #2b6cb0;   /* default / k8s blue */
  --code-bg:    #f4f3ee;
  --measure:    44rem;
  --serif: Charter, "Iowan Old Style", Palatino, Georgia, serif;
  --mono:  "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }
html { font-size: 18px; }
body {
  font-family: var(--serif);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.55;
  margin: 0;
  padding: 4rem 1.5rem 6rem;
}
.home { max-width: var(--measure); margin: 0 auto; }

/* ---- Masthead ---- */
.masthead { margin-bottom: 3rem; }
.eyebrow {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.5rem;
}
h1 {
  font-weight: 600;
  font-size: 2.6rem;
  line-height: 1.05;
  margin: 0 0 0.7rem;
  letter-spacing: -0.01em;
}
.lede {
  font-size: 1.14rem;
  color: var(--ink-soft);
  margin: 0;
  max-width: 38rem;
}

a { color: var(--accent); text-decoration: none; }
strong { font-weight: 600; }
em { font-style: italic; }
code {
  font-family: var(--mono);
  font-size: 0.82em;
  background: var(--code-bg);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

/* ---- Track index ---- */
html { scroll-behavior: smooth; }
.track-index {
  border: 1px solid var(--rule);
  border-radius: 10px;
  background: #fff;
  padding: 1.1rem 1.4rem;
  margin: 0 0 2rem;
}
.index-label {
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin: 0 0 0.6rem;
}
.track-index ul { list-style: none; margin: 0; padding: 0; }
.track-index li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.7rem;
  padding: 0.4rem 0;
}
.track-index li + li { border-top: 1px solid var(--rule); }
.track-index li[data-accent="k8s"] { --accent: #2b6cb0; }
.track-index li[data-accent="mcp"] { --accent: #8a1c1c; }
.track-index a {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 600;
  font-size: 1.02rem;
  color: var(--ink);
  border-bottom: 1px solid transparent;
}
.track-index a:hover { color: var(--accent); }
.track-index .dot {
  width: 0.65rem;
  height: 0.65rem;
  border-radius: 50%;
  background: var(--accent);
  flex: 0 0 auto;
}
.track-index .count {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink-soft);
  white-space: nowrap;
}

/* ---- Topic card ---- */
.topic {
  --accent: #2b6cb0;
  scroll-margin-top: 1.5rem;
  border: 1px solid var(--rule);
  border-top: 4px solid var(--accent);
  border-radius: 10px;
  background: #fff;
  padding: 1.6rem 1.7rem 1.4rem;
  margin: 2rem 0;
}
.topic[data-accent="k8s"] { --accent: #2b6cb0; }   /* blue */
.topic[data-accent="mcp"] { --accent: #8a1c1c; }   /* deep red */

.topic-head { margin-bottom: 1.2rem; }
.badge {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #fff;
  background: var(--accent);
  padding: 0.18em 0.55em;
  border-radius: 4px;
  margin-bottom: 0.6rem;
}
.topic h2 {
  font-weight: 600;
  font-size: 1.55rem;
  margin: 0 0 0.4rem;
}
.topic-lede {
  color: var(--ink-soft);
  font-size: 1rem;
  margin: 0;
}

/* ---- Lesson list ---- */
.lessons { list-style: none; padding: 0; margin: 0; }
.lessons li { margin: 0; }
.lessons li + li { border-top: 1px solid var(--rule); }
.lessons a {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  padding: 0.85rem 0.5rem;
  border-radius: 7px;
  transition: background 0.12s;
}
.lessons a:hover { background: rgba(0,0,0,0.025); }
.lessons .num {
  font-family: var(--mono);
  font-weight: 700;
  color: #fff;
  background: var(--accent);
  min-width: 1.9rem;
  height: 1.9rem;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 0.82rem;
  flex: 0 0 auto;
  margin-top: 0.1rem;
}
.lessons .body { min-width: 0; }
.lessons .t {
  display: block;
  font-weight: 600;
  font-size: 1.06rem;
  color: var(--ink);
}
.lessons a:hover .t { color: var(--accent); }
.lessons .d {
  display: block;
  font-size: 0.92rem;
  color: var(--ink-soft);
  margin-top: 0.15rem;
}

/* ---- Reference link ---- */
.topic-ref {
  margin-top: 1.2rem;
  padding-top: 1rem;
  border-top: 2px solid var(--rule);
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  flex-wrap: wrap;
}
.topic-ref a {
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 600;
}
.ref-note { font-size: 0.85rem; color: var(--ink-soft); font-style: italic; }

/* ---- Footer ---- */
.home-footer {
  margin-top: 3.5rem;
  padding-top: 1.4rem;
  border-top: 1px solid var(--rule);
  text-align: center;
  font-size: 0.85rem;
  color: var(--ink-soft);
}
.home-footer code { background: none; color: var(--accent); }

@media (max-width: 480px) {
  h1 { font-size: 2.1rem; }
  .topic { padding: 1.3rem 1.1rem; }
}