/* ============================================================
   علوم البيانات — نظام التصميم المشترك
   Minimal-color design system: paper, ink, one accent.
   ============================================================ */

:root{
  --paper:#fbfaf7;
  --ink:#23262b;
  --muted:#6b7076;
  --line:#e4e1d7;
  --line-soft:#efede6;
  --accent:#1f5f6b;
  --accent-deep:#174b55;
  --soft:#eef3f3;
  --ok:#1e7a3c;
  --ok-soft:#e9f4ec;
  --bad:#b0392e;
  --bad-soft:#f9eceb;
  --warn:#8a6d1a;
  --warn-soft:#f9f4e2;
  --radius:14px;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:'IBM Plex Sans Arabic','Segoe UI',Tahoma,sans-serif;
  font-size:17px;
  line-height:1.95;
}
p{margin:.5em 0 1em}
strong{font-weight:700}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}

/* English inline terms */
.en{
  font-family:'IBM Plex Sans','Segoe UI',sans-serif;
  direction:ltr;
  unicode-bidi:isolate;
  font-weight:600;
  font-size:.88em;
  background:#f0f2f3;
  border:1px solid var(--line);
  border-radius:7px;
  padding:0 .45em;
  white-space:nowrap;
}
.en.big{font-size:1em}

/* ---------- top navigation ---------- */
.topnav{
  position:sticky;top:0;z-index:50;
  background:rgba(251,250,247,.94);
  backdrop-filter:blur(6px);
  border-bottom:1px solid var(--line);
}
.nav-in{display:flex;align-items:center;justify-content:space-between;gap:10px;flex-wrap:wrap;padding-block:10px}
.brand{font-weight:700;font-size:1.05rem;color:var(--ink);white-space:nowrap}
.brand:hover{text-decoration:none;color:var(--accent)}
.brand .en{margin-inline-start:.35em}
.nav-links{display:flex;gap:4px;flex-wrap:wrap}
.nav-links a{
  color:var(--muted);
  padding:.35em .85em;
  border-radius:999px;
  font-size:.92rem;
  font-weight:600;
}
.nav-links a:hover{color:var(--ink);background:var(--soft);text-decoration:none}
.nav-links a.active{color:#fff;background:var(--accent)}

/* ---------- layout ---------- */
.wrap{max-width:980px;margin-inline:auto;padding-inline:22px}
main{padding-bottom:40px}

/* ---------- lesson header ---------- */
.lesson-head{padding-block:38px 6px}
.crumbs{color:var(--muted);font-size:.85rem;margin-bottom:14px}
.crumbs a{color:var(--muted)}
.head-row{display:flex;align-items:center;gap:18px;flex-wrap:wrap}
.classno{
  flex:none;
  display:grid;place-items:center;
  width:64px;height:64px;
  border:3px solid var(--ink);
  border-radius:18px;
  font-weight:800;font-size:1.7rem;
  background:#fff;
}
h1{font-size:1.9rem;line-height:1.4;margin:.2em 0;font-weight:800}
h1 small{display:block;font-weight:500;color:var(--muted);font-size:.6em}
.unit-tag{
  display:inline-block;
  font-family:'IBM Plex Sans','Segoe UI',sans-serif;
  direction:ltr;
  font-size:.72rem;letter-spacing:.12em;
  color:var(--accent);
  border:1px solid var(--accent);
  border-radius:999px;
  padding:.2em .9em;
  font-weight:600;
  margin-bottom:10px;
}
.lede{color:var(--muted);font-size:1.06rem;max-width:52em}

/* lesson map chips */
.map{display:flex;flex-wrap:wrap;gap:8px;margin-block:20px}
.map a{
  font-size:.85rem;font-weight:600;
  color:var(--ink);
  background:#fff;
  border:1px solid var(--line);
  border-radius:999px;
  padding:.3em 1em;
}
.map a:hover{border-color:var(--accent);color:var(--accent);text-decoration:none}
.map .lbl{font-size:.85rem;color:var(--muted);align-self:center}

/* ---------- headings ---------- */
h2{
  font-size:1.45rem;font-weight:800;
  margin:2.4em 0 .6em;
  padding-inline-start:.55em;
  border-inline-start:6px solid var(--accent);
  line-height:1.5;
}
h3{font-size:1.12rem;font-weight:700;margin:1.6em 0 .4em}
h4{font-size:1rem;font-weight:700;margin:1.2em 0 .3em}

/* ---------- objective sections ---------- */
.obj{
  background:#fff;
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:24px 26px;
  margin-block:22px;
  box-shadow:0 1px 2px rgba(30,40,45,.03);
}
.obj-head{display:flex;align-items:center;gap:14px;margin-bottom:6px}
.obj-badge{
  flex:none;
  display:grid;place-items:center;
  width:46px;height:46px;
  border-radius:13px;
  background:var(--accent);
  color:#fff;
  font-weight:800;font-size:1.15rem;
}
.obj-title{font-size:1.2rem;font-weight:800;line-height:1.6}
.obj-sub{color:var(--muted);font-size:.95rem}

/* ---------- special boxes ---------- */
.child-box,.tip-box,.apply-box,.notice{
  border-radius:12px;
  padding:16px 20px;
  margin-block:16px;
}
.box-title{font-weight:800;margin:0 0 .35em;display:flex;gap:.5em;align-items:center;font-size:1.02rem}
.child-box{border:2px dashed #cbb45e;background:#fdfaf0}
.tip-box{border:2px dashed #7ba6b0;background:var(--soft)}
.apply-box{border:1px solid var(--line);background:#fff}
.notice{border:1px solid #d9b1ac;background:var(--bad-soft);border-inline-start:5px solid var(--bad)}
.notice .box-title{color:var(--bad)}
.child-box ul,.tip-box ul,.apply-box ul{margin:.3em 0;padding-inline-start:1.5em}

/* reveal answers */
details.reveal{
  background:#fff;
  border:1px solid var(--line);
  border-radius:10px;
  margin-block:8px;
  overflow:hidden;
}
details.reveal summary{
  cursor:pointer;
  padding:.65em 1em;
  font-weight:600;
  list-style:none;
  position:relative;
}
details.reveal summary::after{content:"▾";position:absolute;inset-inline-end:1em;color:var(--muted)}
details.reveal[open] summary::after{content:"▴"}
details.reveal summary:hover{background:var(--soft)}
details.reveal .reveal-body{padding:.2em 1.1em .9em;border-top:1px dashed var(--line)}
details.reveal .reveal-body p{margin-top:.5em}

/* ---------- tables ---------- */
.glossary{width:100%;border-collapse:collapse;background:#fff;font-size:.95rem;margin-block:12px;border-radius:12px;overflow:hidden;box-shadow:0 0 0 1px var(--line)}
.glossary th{
  background:var(--soft);
  color:var(--accent-deep);
  font-weight:700;
  text-align:start;
  padding:.55em .9em;
  border-bottom:2px solid var(--line);
  font-size:.85rem;
}
.glossary td{padding:.5em .9em;border-bottom:1px solid var(--line-soft);vertical-align:top}
.glossary tr:last-child td{border-bottom:none}
.glossary tr:nth-child(even) td{background:#fdfdfb}

/* generic table */
table.tbl{border-collapse:collapse;margin-block:10px;background:#fff}
.tbl th,.tbl td{border:1px solid var(--line);padding:.45em .8em;font-size:.92rem}
.tbl th{background:var(--soft)}

/* ---------- lesson prev/next ---------- */
.lesson-nav{
  display:flex;justify-content:space-between;gap:12px;
  margin-top:46px;
  border-top:1px solid var(--line);
  padding-top:18px;
  flex-wrap:wrap;
}
.lesson-nav a{
  background:#fff;border:1px solid var(--line);border-radius:10px;
  padding:.5em 1.1em;font-weight:600;font-size:.95rem;color:var(--ink);
}
.lesson-nav a:hover{border-color:var(--accent);color:var(--accent);text-decoration:none}

/* ---------- buttons ---------- */
.btn{
  display:inline-block;
  font:inherit;font-weight:700;
  border:1.5px solid var(--accent);
  background:#fff;color:var(--accent);
  border-radius:10px;
  padding:.45em 1.4em;
  cursor:pointer;
  transition:transform .06s ease;
}
.btn:hover{text-decoration:none;background:var(--soft)}
.btn:active{transform:scale(.97)}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:var(--accent-deep);color:#fff}
.btn:disabled{opacity:.45;cursor:not-allowed}
.btn-ghost{border-color:var(--line);color:var(--muted)}
.btn-row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}

/* ============================================================
   QUIZ ENGINE (assets/quiz.js renders these)
   ============================================================ */
.quiz-shell{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px 26px;margin-block:20px;box-shadow:0 1px 2px rgba(30,40,45,.04)}
.quiz-top{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:10px}
.quiz-meta{font-size:.9rem;color:var(--muted);font-weight:600}
.qprog{height:9px;background:var(--line-soft);border-radius:99px;overflow:hidden;margin-bottom:20px}
.qprog>i{display:block;height:100%;width:0;background:var(--accent);border-radius:99px;transition:width .35s ease}

.qcard{border-top:1px dashed var(--line);padding-top:16px}
.qtext{font-size:1.12rem;font-weight:700;line-height:2;margin:.2em 0 1em}
.qdiff{
  display:inline-block;
  font-size:.75rem;font-weight:700;
  border:1.5px solid;border-radius:999px;
  padding:.05em .8em;margin-bottom:.6em;
}
.qdiff.d1{color:var(--ok);border-color:var(--ok)}
.qdiff.d2{color:var(--warn);border-color:var(--warn)}
.qdiff.d3{color:var(--bad);border-color:var(--bad)}

.qopt{
  display:flex;align-items:center;gap:.7em;
  width:100%;text-align:start;
  font:inherit;line-height:1.8;
  background:#fff;
  border:1.5px solid var(--line);
  border-radius:11px;
  padding:.55em 1em;
  margin-block:7px;
  cursor:pointer;
}
.qopt:hover:not(:disabled){border-color:var(--accent);background:var(--soft)}
.qopt:disabled{cursor:default}
.qopt .k{
  flex:none;
  font-family:'IBM Plex Sans',sans-serif;
  display:grid;place-items:center;
  min-width:1.9em;height:1.9em;
  border:1px solid var(--line);
  border-radius:8px;
  font-size:.85rem;font-weight:600;color:var(--muted);
  background:#fafaf8;
}
.qopt.correct{border-color:var(--ok);background:var(--ok-soft)}
.qopt.correct .k{border-color:var(--ok);color:var(--ok);background:#fff}
.qopt.wrong{border-color:var(--bad);background:var(--bad-soft)}
.qopt.wrong .k{border-color:var(--bad);color:var(--bad);background:#fff}
.qopt.dim{opacity:.55}

.qfb{border-radius:11px;padding:.85em 1.1em;margin-top:14px;border:1px solid;line-height:1.9}
.qfb.ok{border-color:#bfe0c9;background:var(--ok-soft)}
.qfb.bad{border-color:#e5c0bc;background:var(--bad-soft)}
.qfb b{display:block;margin-bottom:.15em}
.qfoot{display:flex;justify-content:flex-end;gap:10px;margin-top:16px}

.end-card{text-align:center;padding-block:18px}
.grade{font-size:3rem;font-weight:800;line-height:1.2}
.grade.g-high{color:var(--ok)}
.grade.g-mid{color:var(--warn)}
.grade.g-low{color:var(--bad)}
.score-line{color:var(--muted);font-size:1.02rem;margin-block:.4em}
.review-item{
  border:1px solid var(--line);border-radius:11px;
  padding:.8em 1em;margin-block:9px;
  text-align:start;background:#fff;font-size:.95rem;
}
.review-item .rq{font-weight:700;margin-bottom:.25em;line-height:1.9}
.review-item .ra{color:var(--ok);font-weight:600}
.review-item .ry{color:var(--bad);font-weight:600}
.review-item .rx{color:var(--muted);border-top:1px dashed var(--line);padding-top:.3em;margin-top:.3em;line-height:1.9}

/* ============================================================
   HOMEPAGE / HUB
   ============================================================ */
.hero{padding-block:52px 26px;text-align:center}
.hero h1{font-size:2.4rem;margin-bottom:.2em}
.hero .lede{margin-inline:auto;text-align:center}
.hero .chips{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;margin-top:18px}
.chip{
  font-size:.85rem;font-weight:600;
  background:#fff;border:1px solid var(--line);border-radius:999px;
  padding:.3em 1em;color:var(--muted);
}

.grid-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(290px,1fr));gap:16px;margin-block:18px}
.card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:20px 22px;position:relative;
  display:flex;flex-direction:column;gap:.4em;
  transition:border-color .15s ease;
}
.card:hover{border-color:var(--accent)}
.card .card-num{
  position:absolute;top:14px;inset-inline-end:16px;
  font-family:'IBM Plex Sans',sans-serif;
  font-size:1.6rem;font-weight:800;color:var(--line);
}
.card h3{margin:0;font-size:1.08rem}
.card p{color:var(--muted);font-size:.92rem;margin:0;flex:1}
.card .card-links{display:flex;gap:8px;flex-wrap:wrap;margin-top:.7em}
.mini{
  font-size:.82rem;font-weight:700;
  border-radius:8px;padding:.25em .9em;
}
.mini.dark{background:var(--accent);color:#fff}
.mini.light{border:1.5px solid var(--line);color:var(--ink)}
.mini.light:hover{border-color:var(--accent);color:var(--accent)}

.unit-band{
  border:1.5px solid var(--ink);border-radius:var(--radius);
  padding:10px 20px;margin-top:38px;background:#fff;
  display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap;
}
.unit-band h2{margin:0;border:none;padding:0;font-size:1.15rem}
.unit-band .note{color:var(--muted);font-size:.9rem}

.game-card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:20px 22px;display:flex;flex-direction:column;gap:.4em;
}
.game-card .gicon{font-size:2rem;line-height:1}
.game-card h3{margin:.1em 0 0}
.game-card p{color:var(--muted);font-size:.92rem;margin:0;flex:1}
.game-card .tags{display:flex;gap:6px;flex-wrap:wrap;margin-top:.5em}
.tag{font-size:.75rem;font-weight:700;border-radius:999px;padding:.1em .75em;border:1px solid var(--line);color:var(--muted)}
.tag.t3d{border-color:var(--accent);color:var(--accent)}

/* ---------- footer ---------- */
footer{
  margin-top:64px;
  border-top:1px solid var(--line);
  padding-block:26px;
  text-align:center;
  color:var(--muted);
  font-size:.88rem;
}
footer .en{font-size:.8em}

/* ---------- responsive ---------- */
@media (max-width:680px){
  body{font-size:16px}
  .wrap{padding-inline:16px}
  h1{font-size:1.55rem}
  .hero h1{font-size:1.8rem}
  .obj{padding:18px 16px}
  .quiz-shell{padding:18px 14px}
  .classno{width:52px;height:52px;font-size:1.35rem;border-radius:14px}
}

/* ---------- SVG figures ---------- */
figure.fig{margin:1.6em 0;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:14px 14px 8px}
figure.fig svg{display:block;width:100%;height:auto;margin:0 auto}
figure.fig figcaption{font-size:.9rem;color:var(--muted);text-align:center;padding:.5em .2em .2em;line-height:1.6}
figure.fig figcaption b{color:var(--ink)}
figure.fig .ftxt{font:600 12px/1.2 'IBM Plex Sans Arabic','Segoe UI',sans-serif}

@media print{
  .topnav,.lesson-nav,.map,.btn{display:none!important}
  body{background:#fff}
  .obj{break-inside:avoid;border:1px solid #ccc}
}