:root {
  --bg: #fdfdfd;
  --fg: #1a1a2e;
  --accent: #0f3460;
  --accent2: #e94560;
  --card: #ffffff;
  --border: #dde1e7;
  --code-bg: #f4f4f8;
  --shadow: 0 2px 8px rgba(0,0,0,.06);
  --radius: 6px;
  --max-w: 960px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f0f1a;
    --fg: #e0e0e8;
    --accent: #5fa8d3;
    --accent2: #e94560;
    --card: #1a1a2e;
    --border: #2a2a40;
    --code-bg: #16162a;
  }
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.7;
  font-size: 17px;
}

/* ---- Language bar ---- */
.lang-bar {
  text-align: center;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: .4rem .8rem;
  font-size: .82rem;
}
.lang-bar a {
  color: var(--accent);
  text-decoration: none;
  margin: 0 .35rem;
  white-space: nowrap;
}
.lang-bar a:hover { text-decoration: underline; }
.lang-bar a.active { font-weight: 700; text-decoration: underline; }

/* ---- Header ---- */
header {
  background: var(--accent);
  color: #fff;
  padding: 3rem 1.5rem 2.5rem;
  text-align: center;
}
header h1 { font-size: 2.2rem; margin-bottom: .4rem; letter-spacing: -.02em; }
header p.subtitle { font-size: 1.15rem; opacity: .88; max-width: 700px; margin: 0 auto; }
header .badge {
  display: inline-block;
  margin-top: 1rem;
  background: var(--accent2);
  color: #fff;
  padding: .3rem .9rem;
  border-radius: 20px;
  font-size: .85rem;
  font-weight: 600;
  letter-spacing: .03em;
}

/* ---- Nav TOC ---- */
nav.toc {
  max-width: var(--max-w);
  margin: 2rem auto;
  padding: 0 1.5rem;
}
nav.toc details { border: 1px solid var(--border); border-radius: var(--radius); padding: .8rem 1.2rem; }
nav.toc summary { cursor: pointer; font-weight: 600; font-size: 1.05rem; }
nav.toc ol { margin-top: .6rem; padding-left: 1.4rem; }
nav.toc li { margin-bottom: .25rem; }
nav.toc a { color: var(--accent); text-decoration: none; }
nav.toc a:hover { text-decoration: underline; }

/* ---- Main ---- */
main { max-width: var(--max-w); margin: 0 auto; padding: 0 1.5rem 3rem; }
section { margin-top: 2.8rem; }
h2 {
  font-size: 1.55rem;
  border-bottom: 3px solid var(--accent);
  padding-bottom: .3rem;
  margin-bottom: 1rem;
}
h3 { font-size: 1.15rem; margin: 1.4rem 0 .6rem; color: var(--accent); }
h4 { font-size: 1rem; margin: 1rem 0 .4rem; }
p, li { margin-bottom: .55rem; }
ul, ol { padding-left: 1.4rem; }

/* ---- Cards ---- */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.2rem 1.4rem;
  margin: 1rem 0;
  box-shadow: var(--shadow);
}
.card h4 { margin-top: 0; }

/* ---- Tables ---- */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: .92rem;
}
th, td {
  border: 1px solid var(--border);
  padding: .5rem .7rem;
  text-align: left;
}
th { background: var(--accent); color: #fff; font-weight: 600; }
tr:nth-child(even) { background: var(--code-bg); }

/* ---- Code / pipeline ---- */
pre, code { font-family: "Fira Code", "Cascadia Code", monospace; }
pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  overflow-x: auto;
  font-size: .88rem;
  line-height: 1.55;
  margin: 1rem 0;
}
code { background: var(--code-bg); padding: .15em .35em; border-radius: 3px; font-size: .9em; }

/* ---- Highlight box ---- */
.highlight {
  border-left: 4px solid var(--accent2);
  background: var(--code-bg);
  padding: 1rem 1.2rem;
  margin: 1.2rem 0;
  border-radius: 0 var(--radius) var(--radius) 0;
}

/* ---- Grid ---- */
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin: 1rem 0; }
@media (max-width: 640px) { .grid2 { grid-template-columns: 1fr; } }

/* ---- Footer ---- */
footer {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 2rem 1.5rem;
  border-top: 1px solid var(--border);
  font-size: .85rem;
  color: #888;
  text-align: center;
}
footer a { color: var(--accent); }

/* ---- Refs ---- */
.ref-list { font-size: .88rem; }
.ref-list li { margin-bottom: .4rem; }

/* ---- RTL support (Arabic) ---- */
[dir="rtl"] .highlight {
  border-left: none;
  border-right: 4px solid var(--accent2);
  border-radius: var(--radius) 0 0 var(--radius);
}
[dir="rtl"] ul, [dir="rtl"] ol { padding-left: 0; padding-right: 1.4rem; }
[dir="rtl"] nav.toc ol { padding-left: 0; padding-right: 1.4rem; }
[dir="rtl"] th, [dir="rtl"] td { text-align: right; }