/* ============================================================
   منهج TypeScript — نظام تصميم "سبّورة البرهان"
   Proof Chalkboard: set-theory / theorem-prover dark theme
   الثيم مشتقّ من جوّ الموضوع: صرامة رياضية، بناء برهاني،
   جدارٌ بين عالم الأنواع وعالم القيم.
   ============================================================ */

:root {
  /* ---- surfaces: deep cool ink-slate chalkboard ---- */
  --bg-void: #080b12;
  --bg-deep: #0b1019;
  --bg-panel: #101725;
  --bg-elevated: #16223a;
  --bg-code: #0a0f1a;

  /* ---- borders / lines (chalk-drawn structure) ---- */
  --line: #1d2a42;
  --line-strong: #2c3f60;
  --line-faint: #131d2e;

  /* ---- text: chalk on slate ---- */
  --fg: #e4e9f2;
  --fg-muted: #9aa7c0;
  --fg-dim: #65728d;
  --fg-faint: #414c63;

  /* ---- dominant: chalk azure (echo of TS blue, brightened) ---- */
  --accent: #56c2ff;
  --accent-dim: #2a6e9e;
  --accent-glow: rgba(86, 194, 255, 0.5);

  /* ---- secondary: chalk violet (set membership / Venn) ---- */
  --violet: #b3a4ff;
  --violet-dim: #5d51a0;

  /* ---- semantic, fixed meaning ---- */
  --warn: #f4c264;       /* amber */
  --warn-dim: #8a6a1f;
  --danger: #ff6b8a;     /* rose */
  --danger-dim: #8a2e42;
  --info: #6ee7c4;       /* chalk mint */
  --info-dim: #2f7a63;

  /* ---- code keyword tint ---- */
  --kw: #f08bd0;         /* chalk magenta */

  /* ---- type ---- */
  --mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, "SFMono-Regular", monospace;
  --ar: "IBM Plex Sans Arabic", "Tajawal", "Noto Sans Arabic", system-ui, sans-serif;
  --serif: "Spectral", "Newsreader", "Source Serif 4", Georgia, serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0;
  background: var(--bg-void);
  color: var(--fg);
  font-family: var(--ar);
  font-size: 16px;
  line-height: 1.78;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* atmosphere: faint graph-paper grid (set diagrams) + soft radial glows */
body {
  background-image:
    linear-gradient(rgba(86, 194, 255, 0.022) 1px, transparent 1px),
    linear-gradient(90deg, rgba(86, 194, 255, 0.022) 1px, transparent 1px),
    radial-gradient(ellipse at 12% 0%, rgba(86, 194, 255, 0.05) 0%, transparent 45%),
    radial-gradient(ellipse at 88% 8%, rgba(179, 164, 255, 0.045) 0%, transparent 45%);
  background-size: 32px 32px, 32px 32px, 100% 100%, 100% 100%;
  background-attachment: fixed;
  min-height: 100vh;
}

::selection { background: var(--accent); color: var(--bg-void); }

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid var(--accent-dim);
  transition: color 0.13s, border-color 0.13s;
}
a:hover { color: var(--violet); border-color: var(--violet); }

/* ============================================================
   LAYOUT
   ============================================================ */

.shell { display: grid; grid-template-columns: 320px 1fr; min-height: 100vh; }

.topbar {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 24px;
  padding: 10px 28px;
  background: rgba(8, 11, 18, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11px; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--fg-dim);
}
.topbar .brand {
  color: var(--accent); font-weight: 700;
  display: flex; align-items: center; gap: 8px;
  border: none;
}
.topbar .brand::before {
  content: "λ"; /* prover/lambda glyph */
  font-family: var(--serif); font-style: italic;
  color: var(--accent); font-size: 15px;
}
.topbar .meta { display: flex; gap: 18px; flex-wrap: wrap; }
.topbar .meta b { color: var(--violet); font-weight: 500; }
.topbar .spacer { flex: 1; }
.topbar .status { color: var(--info); display: flex; align-items: center; gap: 7px; }
.topbar .status::before {
  content: ""; width: 8px; height: 8px;
  background: var(--info); border-radius: 50%;
  box-shadow: 0 0 8px var(--info);
  animation: pulse 2.2s ease-in-out infinite;
}
@keyframes pulse { 0%,100% { opacity: 1; transform: scale(1); } 50% { opacity: 0.4; transform: scale(0.7); } }

/* sidebar */
.sidebar {
  position: sticky; top: 39px; height: calc(100vh - 39px);
  overflow-y: auto;
  background: var(--bg-deep);
  border-left: 1px solid var(--line);
  padding: 28px 22px 60px;
  font-family: var(--mono); font-size: 13px;
}
.sidebar .sb-title {
  font-size: 10px; letter-spacing: 0.2em; text-transform: uppercase;
  color: var(--fg-dim);
  margin: 22px 0 8px;
  display: flex; align-items: center; gap: 8px;
}
.sidebar .sb-title::before {
  content: "∈"; /* set membership — topic-derived bullet */
  font-size: 12px; color: var(--accent); font-family: var(--mono);
}
.sidebar .sb-title:first-child { margin-top: 0; }
.sidebar a {
  display: flex; align-items: flex-start; gap: 10px;
  padding: 7px 10px;
  border: none; border-radius: 0;
  color: var(--fg-muted);
  border-right: 2px solid transparent;
  font-size: 13px; line-height: 1.5; margin-bottom: 1px;
  transition: all 0.12s;
}
.sidebar a:hover { background: var(--bg-panel); color: var(--fg); border-right-color: var(--accent-dim); }
.sidebar a.active { background: var(--bg-panel); color: var(--accent); border-right-color: var(--accent); }
.sidebar a .num { color: var(--fg-dim); font-size: 11px; flex-shrink: 0; min-width: 22px; }
.sidebar a.active .num { color: var(--accent); }

.sb-cheat {
  font-family: var(--mono); font-size: 11px; color: var(--fg-dim);
  padding: 4px 10px; line-height: 1.95;
  border-right: 2px solid var(--line-strong); margin-top: 4px;
}
.sb-cheat b { color: var(--accent); font-weight: 500; }
.sb-cheat i { color: var(--violet); font-style: normal; }
.sb-cheat u { color: var(--warn); text-decoration: none; }

/* main */
.main { padding: 56px 64px 120px; max-width: 1100px; width: 100%; }

/* ============================================================
   TYPE
   ============================================================ */

h1, h2, h3, h4 { font-family: var(--ar); font-weight: 700; color: var(--fg); line-height: 1.3; text-wrap: balance; }

h1 { font-size: clamp(32px, 4vw, 50px); margin: 0 0 12px; letter-spacing: -0.01em; }
h1 .accent { color: var(--accent); }
h1 .serif { font-family: var(--serif); font-style: italic; font-weight: 600; }

h2 {
  font-size: 29px; margin: 64px 0 18px; padding-bottom: 14px;
  border-bottom: 1px solid var(--line); position: relative;
}
h2::before {
  content: attr(data-num);
  display: inline-block; font-family: var(--mono); font-size: 13px;
  color: var(--accent); margin-left: 14px; padding: 2px 8px;
  background: rgba(86, 194, 255, 0.07);
  border: 1px solid var(--accent-dim);
  letter-spacing: 0.05em; vertical-align: middle;
}

h3 { font-size: 21px; margin: 40px 0 12px; color: var(--violet); }
h3::before { content: "// "; font-family: var(--mono); color: var(--fg-dim); font-weight: 400; }

h4 { font-size: 16px; margin: 28px 0 10px; color: var(--warn); font-family: var(--mono); font-weight: 500; letter-spacing: 0.02em; }

p { margin: 0 0 16px; text-wrap: pretty; }
strong, b { color: var(--fg); font-weight: 700; }
em { color: var(--violet); font-style: normal; font-weight: 500; }

ul, ol { padding-right: 24px; margin: 0 0 18px; }
li { margin-bottom: 8px; }
li::marker { color: var(--accent); }
ul ul, ul ol, ol ul, ol ol { margin: 8px 0 4px; }

hr { border: none; border-top: 1px solid var(--line); margin: 40px 0; }

/* English / code inline */
code, .en { font-family: var(--mono); direction: ltr; unicode-bidi: isolate; }
code {
  background: var(--bg-elevated); color: var(--accent);
  padding: 1px 6px; font-size: 0.86em;
  border: 1px solid var(--line); border-radius: 2px;
}

/* pull-quote feel for set-notation lines in prose */
.note-set { font-family: var(--serif); font-style: italic; color: var(--info); }

/* ============================================================
   HERO
   ============================================================ */

.hero { padding: 78px 64px 56px; border-bottom: 1px solid var(--line); position: relative; overflow: hidden; }
.hero::before {
  content: "";
  position: absolute; inset: 0; pointer-events: none;
  background:
    radial-gradient(circle at 18% 28%, rgba(86, 194, 255, 0.10) 0%, transparent 42%),
    radial-gradient(circle at 82% 72%, rgba(179, 164, 255, 0.08) 0%, transparent 42%);
}
/* faint set-theory watermark, topic-derived (not decoration-for-decoration) */
.hero::after {
  content: "T ⊆ unknown   ∅ = never   A | B   A & B   x: T ⟺ x ∈ T";
  position: absolute; left: 64px; bottom: 14px; right: 64px;
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.1em;
  color: var(--accent); opacity: 0.10; white-space: nowrap; overflow: hidden;
  direction: ltr; pointer-events: none;
}
.hero > * { position: relative; }
.hero-meta { display: flex; gap: 14px; margin-bottom: 24px; font-family: var(--mono); font-size: 12px; color: var(--fg-dim); letter-spacing: 0.06em; text-transform: uppercase; flex-wrap: wrap; }
.hero-meta .tag { padding: 4px 10px; border: 1px solid var(--line); background: var(--bg-panel); color: var(--fg-muted); }
.hero-meta .tag.live { color: var(--info); border-color: var(--info-dim); }
.hero-meta .tag.key { color: var(--accent); border-color: var(--accent-dim); }
.hero h1 { font-size: clamp(38px, 5.2vw, 70px); font-weight: 800; line-height: 1.06; margin: 0 0 16px; }
.hero .lede { font-size: 19px; color: var(--fg-muted); max-width: 800px; line-height: 1.75; }

/* ============================================================
   PANELS / CALLOUTS / BOX
   ============================================================ */

.panel { background: var(--bg-panel); border: 1px solid var(--line); padding: 22px 26px; margin: 22px 0; position: relative; }
.panel.bracket::before, .panel.bracket::after { content: ""; position: absolute; width: 14px; height: 14px; border: 1px solid var(--accent); }
.panel.bracket::before { top: -1px; right: -1px; border-bottom: none; border-left: none; }
.panel.bracket::after { bottom: -1px; left: -1px; border-top: none; border-right: none; }
.panel .label { font-family: var(--mono); font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent); margin-bottom: 8px; }
.panel p:last-child, .panel ul:last-child, .panel ol:last-child { margin-bottom: 0; }

.callout {
  margin: 24px 0; padding: 16px 22px;
  background: var(--bg-panel);
  border-right: 3px solid var(--accent);
  border-left: 1px solid var(--line); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
  position: relative;
}
.callout.warn { border-right-color: var(--warn); }
.callout.danger { border-right-color: var(--danger); }
.callout.info { border-right-color: var(--info); }
.callout.seed { border-right-color: var(--violet); background: linear-gradient(90deg, rgba(179,164,255,0.05), var(--bg-panel) 60%); }
.callout .label {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 6px; display: flex; align-items: center; gap: 8px;
}
.callout.warn .label { color: var(--warn); }
.callout.danger .label { color: var(--danger); }
.callout.info .label { color: var(--info); }
.callout.seed .label { color: var(--violet); }
.callout.seed .label::before { content: "✦"; }
.callout p:last-child, .callout ul:last-child, .callout ol:last-child { margin-bottom: 0; }

.box { margin: 28px 0; border: 1px solid var(--line); background: var(--bg-panel); padding: 24px 26px 22px; position: relative; }
.box::before {
  content: attr(data-label); position: absolute; top: -10px; right: 20px;
  background: var(--bg-void); padding: 0 10px;
  font-family: var(--mono); font-size: 11px; color: var(--accent);
  letter-spacing: 0.15em; text-transform: uppercase;
}
.box.puzzle { border-color: var(--warn-dim); }
.box.puzzle::before { color: var(--warn); }
.box.puzzle::after {
  content: "⚠"; position: absolute; top: 18px; left: 22px;
  color: var(--warn-dim); font-size: 16px;
}
.box > :last-child { margin-bottom: 0; }

/* ============================================================
   TABLES
   ============================================================ */
table { width: 100%; border-collapse: collapse; margin: 22px 0; font-size: 14px; background: var(--bg-panel); border: 1px solid var(--line); }
th { background: var(--bg-elevated); color: var(--accent); font-family: var(--mono); font-size: 12px; font-weight: 500; letter-spacing: 0.04em; text-align: right; padding: 12px 16px; border-bottom: 1px solid var(--line-strong); }
td { padding: 11px 16px; border-bottom: 1px solid var(--line-faint); vertical-align: top; color: var(--fg-muted); }
td:first-child { color: var(--fg); }
tr:last-child td { border-bottom: none; }
tr:hover td { background: rgba(86, 194, 255, 0.025); }

/* ============================================================
   CODE BLOCKS / TERMINAL
   ============================================================ */
pre { background: var(--bg-code); border: 1px solid var(--line); padding: 0; margin: 22px 0; overflow: hidden; font-family: var(--mono); font-size: 13.5px; line-height: 1.65; position: relative; }
pre .term-head { display: flex; align-items: center; gap: 10px; padding: 8px 14px; background: var(--bg-elevated); border-bottom: 1px solid var(--line); font-size: 11px; color: var(--fg-dim); letter-spacing: 0.08em; text-transform: uppercase; }
pre .term-head::before { content: "● ● ●"; color: var(--fg-faint); letter-spacing: 2px; font-size: 8px; }
pre .term-head .tt { color: var(--accent); margin-right: auto; }
pre code { display: block; padding: 18px 20px; background: transparent; border: none; color: var(--fg); white-space: pre; overflow-x: auto; direction: ltr; text-align: left; font-size: 13.5px; }
pre code .pmt { color: var(--info); }
pre code .cmt { color: var(--fg-dim); font-style: italic; }
pre code .kw  { color: var(--kw); }
pre code .str { color: var(--warn); }
pre code .num { color: var(--accent); }
pre code .typ { color: var(--info); }

/* ============================================================
   ASCII FRAMES
   ============================================================ */
.ascii { font-family: var(--mono); font-size: 12.5px; line-height: 1.5; white-space: pre; background: var(--bg-code); border: 1px solid var(--line); padding: 18px 22px; margin: 22px 0; color: var(--fg-muted); overflow-x: auto; direction: ltr; text-align: left; }
.ascii .hl { color: var(--accent); }
.ascii .hl2 { color: var(--violet); }
.ascii .hl3 { color: var(--warn); }
.ascii .hl4 { color: var(--info); }

/* ============================================================
   MODULE GRID (index)
   ============================================================ */
.modgrid { display: grid; grid-template-columns: repeat(auto-fit, minmax(330px, 1fr)); gap: 16px; margin: 28px 0; }
.modcard { display: block; background: var(--bg-panel); border: 1px solid var(--line); padding: 24px; color: var(--fg); position: relative; transition: all 0.15s ease; overflow: hidden; }
.modcard:hover { border-color: var(--accent-dim); background: var(--bg-elevated); transform: translateY(-2px); }
.modcard::before { content: ""; position: absolute; top: 0; right: 0; width: 64px; height: 64px; background: linear-gradient(225deg, var(--accent-dim) 0%, transparent 55%); opacity: 0.16; }
.modcard .mc-num { font-family: var(--mono); font-size: 11px; color: var(--accent); letter-spacing: 0.15em; margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.modcard .mc-num::after { content: ""; flex: 1; border-top: 1px dashed var(--line-strong); }
.modcard .mc-title { font-size: 21px; font-weight: 700; margin: 0 0 6px; color: var(--fg); line-height: 1.3; }
.modcard .mc-sub { font-size: 12.5px; color: var(--violet); font-family: var(--mono); margin-bottom: 12px; direction: rtl; }
.modcard .mc-desc { font-size: 14px; color: var(--fg-muted); line-height: 1.65; margin-bottom: 16px; }
.modcard .mc-foot { display: flex; justify-content: space-between; align-items: center; font-family: var(--mono); font-size: 11px; color: var(--fg-dim); text-transform: uppercase; letter-spacing: 0.08em; padding-top: 14px; border-top: 1px solid var(--line); }
.modcard .mc-foot .open { color: var(--accent); }
.modcard:hover .mc-foot .open::after { content: " ←"; }
.modcard.appx::before { background: linear-gradient(225deg, var(--violet-dim) 0%, transparent 55%); }
.modcard.appx .mc-num, .modcard.appx .mc-foot .open { color: var(--violet); }
.modcard.appx:hover { border-color: var(--violet-dim); }

/* ============================================================
   PAGER (prev / next)
   ============================================================ */
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin: 64px 0 0; border-top: 1px solid var(--line); padding-top: 28px; }
.pager a { display: block; padding: 18px 22px; background: var(--bg-panel); border: 1px solid var(--line); color: var(--fg); transition: all 0.15s; }
.pager a:hover { border-color: var(--accent-dim); background: var(--bg-elevated); transform: translateY(-2px); }
.pager .label { font-family: var(--mono); font-size: 11px; color: var(--fg-dim); letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 6px; }
.pager .title { font-size: 15px; color: var(--accent); }
.pager .next { text-align: left; }
.pager .next .label::before { content: "→ "; }
.pager .prev .label::after { content: " ←"; }
.pager .seed-title { color: var(--violet); font-size: 13px; margin-top: 4px; font-family: var(--ar); }

/* ============================================================
   BADGES / TOC / STATS
   ============================================================ */
.badge { display: inline-block; padding: 2px 8px; font-family: var(--mono); font-size: 11px; letter-spacing: 0.06em; text-transform: uppercase; border: 1px solid var(--line-strong); color: var(--fg-muted); background: var(--bg-elevated); vertical-align: middle; direction: ltr; }
.badge.ok { color: var(--accent); border-color: var(--accent-dim); }
.badge.bad { color: var(--danger); border-color: var(--danger-dim); }
.badge.warn { color: var(--warn); border-color: var(--warn-dim); }
.badge.info { color: var(--info); border-color: var(--info-dim); }

.toc { background: var(--bg-panel); border: 1px solid var(--line); padding: 18px 26px; margin: 24px 0 32px; font-size: 14px; }
.toc .toc-h { font-family: var(--mono); font-size: 11px; color: var(--fg-dim); letter-spacing: 0.15em; text-transform: uppercase; margin-bottom: 10px; }
.toc ol { padding-right: 18px; margin: 0; }
.toc a { color: var(--fg-muted); border: none; }
.toc a:hover { color: var(--accent); }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 14px; margin: 24px 0; }
.stat { border: 1px solid var(--line); background: var(--bg-panel); padding: 18px; }
.stat .v { font-family: var(--mono); font-size: 30px; color: var(--accent); font-weight: 700; line-height: 1; direction: ltr; }
.stat .k { font-family: var(--mono); font-size: 11px; color: var(--fg-dim); text-transform: uppercase; letter-spacing: 0.1em; margin-top: 8px; }

/* ============================================================
   FOOTER
   ============================================================ */
.foot { border-top: 1px solid var(--line); margin-top: 60px; padding: 28px 64px; font-family: var(--mono); font-size: 11px; color: var(--fg-dim); letter-spacing: 0.08em; text-transform: uppercase; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px; background: var(--bg-void); }
.foot .sig { color: var(--accent); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1000px) {
  .shell { grid-template-columns: 1fr; }
  .sidebar { position: relative; height: auto; top: 0; border-left: none; border-bottom: 1px solid var(--line); }
  .main { padding: 40px 22px 80px; }
  .hero { padding: 56px 22px 40px; }
  .hero::after { display: none; }
  .foot { padding: 28px 22px; }
  .pager { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}