:root{
  --bg:#f7f8fa; --card:#fff; --ink:#1d2433; --muted:#5b6577; --line:#e4e7ec;
  --brand:#0f7b5f; --brand-2:#e8f5f0; --accent:#f2a93b;
  --radius:14px; --max:1080px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:"Tajawal","Segoe UI",Tahoma,sans-serif;background:var(--bg);color:var(--ink);line-height:1.85;font-size:17px}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;display:block}
.wrap{max-width:var(--max);margin:0 auto;padding:0 20px}

/* header */
.site-header{background:var(--card);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:64px;flex-wrap:wrap}
.logo{font-weight:800;font-size:1.5rem;color:var(--ink)}
.logo span{color:var(--brand)}
.logo:hover{text-decoration:none}
nav ul{list-style:none;margin:0;padding:0;display:flex;gap:18px;flex-wrap:wrap}
nav a{color:var(--muted);font-weight:500}
nav a:hover,nav a.active{color:var(--brand);text-decoration:none}

/* hero */
.hero{background:linear-gradient(135deg,#0f7b5f,#13506b);color:#fff;padding:64px 0 56px}
.hero h1{font-size:2.2rem;line-height:1.4;margin:0 0 12px}
.hero p{font-size:1.15rem;opacity:.92;max-width:640px;margin:0 0 24px}
.btn{display:inline-block;background:var(--accent);color:#1d2433;font-weight:700;padding:12px 26px;border-radius:999px}
.btn:hover{text-decoration:none;filter:brightness(1.05)}

/* sections */
section{padding:48px 0}
h2.section-title{font-size:1.6rem;margin:0 0 24px}
.cats{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px}
.cat{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px}
.cat .ico{font-size:1.8rem}
.cat h3{margin:8px 0 4px;font-size:1.15rem}
.cat p{margin:0;color:var(--muted);font-size:.95rem}

.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(290px,1fr));gap:20px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;display:flex;flex-direction:column}
.card .thumb{height:150px;display:flex;align-items:center;justify-content:center;font-size:3rem;color:#fff}
.t1{background:linear-gradient(135deg,#1d8a5f,#2fb37f)}
.t2{background:linear-gradient(135deg,#13506b,#2a86b0)}
.t3{background:linear-gradient(135deg,#7a4bc2,#b07ae0)}
.card .body{padding:18px 20px 22px;flex:1;display:flex;flex-direction:column}
.tag{display:inline-block;background:var(--brand-2);color:var(--brand);font-size:.8rem;font-weight:700;padding:2px 10px;border-radius:999px;margin-bottom:8px;align-self:flex-start}
.card h3{margin:0 0 8px;font-size:1.15rem;line-height:1.6}
.card h3 a{color:var(--ink)}
.card p{margin:0 0 12px;color:var(--muted);font-size:.95rem;flex:1}
.meta{font-size:.85rem;color:var(--muted)}

/* article */
.article{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:36px clamp(20px,5vw,56px);margin:32px auto;max-width:800px}
.article h1{font-size:2rem;line-height:1.5;margin:8px 0 10px}
.article h2{font-size:1.45rem;margin:36px 0 10px;padding-top:8px;border-top:1px solid var(--line)}
.article h3{font-size:1.15rem;margin:24px 0 8px}
.article .lead{font-size:1.1rem;color:var(--muted)}
.breadcrumb{font-size:.9rem;color:var(--muted)}
.toc{background:var(--brand-2);border-radius:10px;padding:14px 22px;margin:22px 0}
.toc strong{display:block;margin-bottom:4px}
.toc ol{margin:0;padding-inline-start:20px}
code,.formula{font-family:Consolas,"Courier New",monospace;direction:ltr;unicode-bidi:embed}
.formula{display:block;background:#1d2433;color:#d7f7e9;padding:14px 18px;border-radius:10px;margin:12px 0;overflow-x:auto;text-align:left;font-size:.95rem}
code{background:#eef1f5;padding:1px 6px;border-radius:5px;font-size:.92em}
table{border-collapse:collapse;width:100%;margin:14px 0;font-size:.95rem}
th,td{border:1px solid var(--line);padding:8px 12px;text-align:right}
th{background:#f1f4f7}
.tip{border-inline-start:4px solid var(--accent);background:#fff8ec;padding:12px 18px;border-radius:8px;margin:18px 0}
.note{border-inline-start:4px solid var(--brand);background:var(--brand-2);padding:12px 18px;border-radius:8px;margin:18px 0}
.related{margin-top:36px;padding-top:18px;border-top:1px solid var(--line)}

/* ad slots: empty until AdSense approval (do not show placeholder boxes to reviewers) */
.ad-slot{margin:24px 0;min-height:0}

/* page */
.page{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:36px clamp(20px,5vw,56px);margin:32px auto;max-width:800px}
.page h1{margin-top:0}
form label{display:block;font-weight:600;margin:14px 0 6px}
form input,form textarea{width:100%;padding:12px;border:1px solid var(--line);border-radius:10px;font:inherit}
form button{margin-top:16px;border:0;cursor:pointer;font:inherit}

/* footer */
.site-footer{background:#1d2433;color:#c8cfdb;padding:36px 0 24px;margin-top:40px;font-size:.95rem}
.site-footer .cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:24px}
.site-footer h4{color:#fff;margin:0 0 8px}
.site-footer a{color:#c8cfdb}
.site-footer ul{list-style:none;padding:0;margin:0}
.copy{border-top:1px solid #2e3747;margin-top:24px;padding-top:16px;text-align:center;font-size:.85rem}

@media (max-width:640px){
  body{font-size:16px}
  .hero{padding:44px 0 40px}
  .hero h1{font-size:1.65rem}
  .article h1{font-size:1.55rem}
  nav ul{gap:12px;font-size:.95rem}
}