:root {
  --bg: #f7f5f1;
  --bg-card: #ffffff;
  --text: #1c1b19;
  --text-dim: #5b564c;
  --border: #e4ded2;
  --accent: #1e4d3a;
  --accent-contrast: #ffffff;
  --highlight: #b5471b;
  --code-bg: #efe9dc;
  --max-width: 880px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15140f;
    --bg-card: #1e1c16;
    --text: #ece7db;
    --text-dim: #b3ac9a;
    --border: #3a362a;
    --accent: #6fbf9a;
    --accent-contrast: #0d1f17;
    --highlight: #e0824a;
    --code-bg: #2a2619;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.55;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.site-header {
  background: var(--accent);
  color: var(--accent-contrast);
  padding: 14px 20px;
  position: sticky;
  top: 0;
  z-index: 10;
}
.site-header .inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}
.site-header .brand {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--accent-contrast);
}
.site-header .brand span { opacity: .75; font-weight: 400; }
.site-header nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  font-size: .92rem;
}
.site-header nav a {
  color: var(--accent-contrast);
  opacity: .85;
}
.site-header nav a:hover, .site-header nav a.active {
  opacity: 1;
  text-decoration: underline;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 28px 20px 80px;
}

h1 { font-size: 1.7rem; line-height: 1.25; margin: .2em 0 .5em; }
h2 { font-size: 1.3rem; margin: 1.6em 0 .5em; border-top: 1px solid var(--border); padding-top: .8em; }
h3 { font-size: 1.08rem; margin: 1.3em 0 .4em; color: var(--accent); }
h4 { font-size: 1rem; margin: 1.1em 0 .3em; }
p { margin: .6em 0; }
ul, ol { padding-left: 1.3em; }
li { margin: .25em 0; }
blockquote {
  margin: 0 0 1.2em;
  padding: 4px 14px;
  border-left: 3px solid var(--accent);
  color: var(--text-dim);
  font-size: .95rem;
}
strong { color: var(--text); }
hr { border: none; border-top: 1px solid var(--border); margin: 2em 0; }
code { background: var(--code-bg); padding: .1em .35em; border-radius: 4px; font-size: .9em; }

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px 20px;
  margin-bottom: 14px;
}
.card a.card-title { font-size: 1.05rem; font-weight: 600; }
.card .meta { color: var(--text-dim); font-size: .85rem; margin-top: 4px; }

.grid { display: grid; gap: 14px; }
@media (min-width: 640px) {
  .grid.two { grid-template-columns: 1fr 1fr; }
}

.pill {
  display: inline-block;
  background: var(--code-bg);
  color: var(--text-dim);
  border-radius: 999px;
  padding: 2px 10px;
  font-size: .78rem;
  margin-right: 6px;
}

.btn {
  display: inline-block;
  background: var(--accent);
  color: var(--accent-contrast) !important;
  padding: 10px 18px;
  border-radius: 8px;
  font-weight: 600;
  font-size: .95rem;
  text-decoration: none !important;
  border: none;
  cursor: pointer;
}
.btn:hover { opacity: .92; }
.btn.secondary {
  background: transparent;
  color: var(--accent) !important;
  border: 1px solid var(--accent);
}

.toc {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 18px;
  margin-bottom: 22px;
  font-size: .92rem;
}
.toc summary { cursor: pointer; font-weight: 600; }
.toc ul { margin: .6em 0 0; }

.progress-box {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: .9rem;
  color: var(--text-dim);
  margin: 1.6em 0;
}

.question-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px 20px;
  margin-bottom: 16px;
}
.question-block .qmeta { font-size: .8rem; color: var(--text-dim); margin-bottom: 8px; }
.question-block .qtext { font-size: 1.02rem; }
.options { margin-top: 10px; }
.options .opt { padding: 8px 10px; border: 1px solid var(--border); border-radius: 6px; margin-bottom: 6px; }

.reveal { margin-top: 10px; }
.reveal summary { cursor: pointer; color: var(--accent); font-weight: 600; font-size: .9rem; }

footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 20px 20px 60px;
  color: var(--text-dim);
  font-size: .82rem;
  border-top: 1px solid var(--border);
}

.breadcrumb { font-size: .85rem; color: var(--text-dim); margin-bottom: 12px; }
.breadcrumb a { color: var(--text-dim); text-decoration: underline; }

.warn {
  background: var(--code-bg);
  border-left: 3px solid var(--highlight);
  padding: 10px 14px;
  border-radius: 6px;
  font-size: .88rem;
  color: var(--text-dim);
  margin: 1.2em 0;
}

.filters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.filters a {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 6px 12px;
  border-radius: 999px;
  font-size: .85rem;
  color: var(--text);
}
.filters a.active { background: var(--accent); color: var(--accent-contrast); border-color: var(--accent); }