/* ============================================================
   Khalid Alnujaidi — Engineering Passport
   Hyper-minimalist. Zero JS. System fonts only. No web fonts,
   no trackers, no external requests. One stylesheet.
   ============================================================ */

:root {
  --paper:      #fbfbf9;
  --ink:        #17171a;
  --ink-muted:  #5d6068;
  --ink-faint:  #9a9da4;
  --rule:       #e4e2db;
  --rule-soft:  #efeee9;
  --accent:     #1f49c4;
  --accent-dim: #45506b;

  --sans: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --measure: 50rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper:      #111113;
    --ink:        #e9e8e3;
    --ink-muted:  #a0a2a8;
    --ink-faint:  #6a6c72;
    --rule:       #2a2a2e;
    --rule-soft:  #1d1d20;
    --accent:     #8fa6ff;
    --accent-dim: #aeb6cc;
  }
}

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

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 3.25rem 1.5rem 4rem;
}

/* ---- Links ---- */
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 2px; }

/* ---- Identity header ---- */
.passport-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem 1rem;
}
.name {
  font-size: 1.7rem;
  font-weight: 650;
  letter-spacing: -0.02em;
  margin: 0;
}
.subtitle {
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.02em;
  color: var(--ink-muted);
  margin: 0.35rem 0 0;
}
.summary {
  margin: 1.1rem 0 0;
  max-width: 44rem;
  color: var(--ink);
}

/* ---- RSS pill ---- */
.rss {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  padding: 0.28rem 0.55rem;
  border: 1px solid var(--rule);
  border-radius: 3px;
  color: var(--accent);
  white-space: nowrap;
}
.rss:hover { border-color: var(--accent); text-decoration: none; }

/* ---- Section scaffolding ---- */
section { margin-top: 2.75rem; }

.sec-label {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--rule);
}
.sec-label::before { content: "§ "; color: var(--accent-dim); }

.group-label {
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.04em;
  color: var(--ink-muted);
  margin: 1.4rem 0 0.5rem;
}
.group-label:first-of-type { margin-top: 0; }

/* ---- Highlights (data-dense bullets) ---- */
ul.dense {
  list-style: none;
  margin: 0;
  padding: 0;
}
ul.dense > li {
  position: relative;
  padding: 0.45rem 0 0.45rem 1.15rem;
  border-bottom: 1px solid var(--rule-soft);
}
ul.dense > li:last-child { border-bottom: none; }
ul.dense > li::before {
  content: "▪";
  position: absolute;
  left: 0;
  color: var(--accent-dim);
  font-size: 0.85em;
  top: 0.55rem;
}
.metric { font-variant-numeric: tabular-nums; font-weight: 600; }

/* ---- Essays (chronological stream) ---- */
ul.stream {
  list-style: none;
  margin: 0;
  padding: 0;
}
ul.stream > li {
  display: flex;
  gap: 1rem;
  align-items: baseline;
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--rule-soft);
}
ul.stream > li:last-child { border-bottom: none; }
.date {
  flex: 0 0 5.5rem;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}
.entry-title { color: var(--ink); }
a.entry-title:hover { color: var(--accent); }
.soon {
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: 0.05rem 0.35rem;
  margin-left: 0.5rem;
  vertical-align: 0.08em;
}

/* ---- Footer ---- */
footer {
  margin-top: 3.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 0.74rem;
  color: var(--ink-muted);
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.9rem;
}
footer .sep { color: var(--ink-faint); }

/* ============================================================
   Essay / long-form pages (essays/*.html)
   ============================================================ */
article.essay { max-width: 42rem; }
article.essay .meta {
  font-family: var(--mono);
  font-size: 0.76rem;
  color: var(--ink-faint);
  margin-bottom: 1.25rem;
}
article.essay h1 {
  font-size: 1.85rem;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0 0 0.4rem;
}
article.essay h2 {
  font-size: 1.2rem;
  letter-spacing: -0.01em;
  margin: 2.2rem 0 0.6rem;
  padding-top: 0.4rem;
}
article.essay h3 {
  font-size: 1rem;
  margin: 1.6rem 0 0.4rem;
  color: var(--ink-muted);
}
article.essay p { margin: 0 0 1.05rem; }
article.essay blockquote {
  margin: 1.2rem 0;
  padding: 0.2rem 0 0.2rem 1rem;
  border-left: 2px solid var(--rule);
  color: var(--ink-muted);
}
article.essay code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--rule-soft);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}
article.essay pre {
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.45;
  background: var(--rule-soft);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 0.85rem 1rem;
  overflow-x: auto;
  margin: 1.2rem 0;
}
article.essay pre code { background: none; padding: 0; font-size: inherit; }

.backlink {
  font-family: var(--mono);
  font-size: 0.76rem;
  color: var(--ink-muted);
  display: inline-block;
  margin-bottom: 1.75rem;
}

/* ---- Small screens ---- */
@media (max-width: 34rem) {
  .wrap { padding: 2.25rem 1.15rem 3rem; }
  ul.stream > li { flex-direction: column; gap: 0.1rem; }
  .date { flex-basis: auto; }
}