/* Al-banna Tutorials — shared page design system, derived from the Deep Learning course template.
   Usage: <link rel="stylesheet" href="/assets/theme.css"> + <script defer src="/assets/theme.js">
   Override the accent per page with:  :root{--primary:#22d3ee}  (and optionally --glow). */
[hidden]{display:none!important}
*{margin:0;padding:0;box-sizing:border-box}
:root{--bg:#0b0f19;--surface:#111827;--surface2:#1e293b;--primary:#6366f1;--primary-hover:#818cf8;--secondary:#22d3ee;--success:#10b981;--text:#f1f5f9;--text2:#94a3b8;--warning:#f59e0b;--danger:#ef4444;--border:rgba(255,255,255,0.06);--border2:rgba(255,255,255,0.08);--footer:#080c14;--code:#0d1117;--glow:rgba(99,102,241,.14);--nav-h:64px}
body.light-mode{--bg:#f0f4f8;--surface:#ffffff;--surface2:#e2e8f0;--text:#0f172a;--text2:#334155;--border:rgba(0,0,0,0.10);--border2:rgba(0,0,0,0.12);--footer:#e2e8f0;--code:#1e293b}
html{scroll-behavior:smooth}
body{font-family:'Inter',system-ui,-apple-system,"Segoe UI",sans-serif;background:var(--bg);color:var(--text);line-height:1.7;overflow-x:hidden}
html[dir=rtl] body{font-family:'Tajawal','Inter',system-ui,sans-serif}
a{color:var(--primary);text-decoration:none;transition:color .2s}a:hover{color:var(--primary-hover)}
img{max-width:100%;height:auto}
/* navbar */
.navbar{position:fixed;top:0;left:0;right:0;background:rgba(11,15,25,.9);backdrop-filter:blur(20px);border-bottom:1px solid var(--border);z-index:1000;padding:0 24px}
body.light-mode .navbar{background:rgba(255,255,255,.92);border-bottom-color:rgba(0,0,0,.08)}
.nav-inner{max-width:1200px;margin:0 auto;display:flex;justify-content:space-between;align-items:center;height:var(--nav-h);gap:12px}
.nav-logo{font-size:1.15rem;font-weight:700;color:var(--text);display:flex;align-items:center;gap:10px;white-space:nowrap}
.nav-logo i{color:var(--primary);font-size:1.3rem}
.nav-links{display:flex;gap:6px;align-items:center;list-style:none}
.nav-links a{color:var(--text2);padding:8px 14px;border-radius:8px;font-size:.875rem;font-weight:500;transition:all .2s;white-space:nowrap}
.nav-links a:hover,.nav-links a.active{color:var(--text);background:rgba(255,255,255,.05)}
body.light-mode .nav-links a:hover,body.light-mode .nav-links a.active{background:rgba(0,0,0,.05)}
.theme-toggle{background:none;border:1px solid var(--border2);color:var(--text2);width:36px;height:36px;border-radius:8px;cursor:pointer;font-size:1rem;display:flex;align-items:center;justify-content:center;transition:all .2s;flex-shrink:0}
.theme-toggle:hover{border-color:var(--primary);color:var(--primary)}
.hamburger{display:none;background:none;border:none;color:var(--text);font-size:1.25rem;cursor:pointer;padding:8px}
.mobile-menu{display:none;position:fixed;top:var(--nav-h);left:0;right:0;background:rgba(11,15,25,.98);backdrop-filter:blur(20px);border-bottom:1px solid var(--border);padding:16px 24px;flex-direction:column;gap:4px;z-index:999}
body.light-mode .mobile-menu{background:rgba(255,255,255,.98)}
.mobile-menu a{color:var(--text2);padding:10px 12px;border-radius:8px}.mobile-menu a:hover{color:var(--text);background:rgba(255,255,255,.05)}
.mobile-menu.open{display:flex}
/* hero */
.hero{margin-top:var(--nav-h);padding:80px 24px 60px;text-align:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:50%;left:50%;width:800px;height:800px;transform:translate(-50%,-50%);background:radial-gradient(circle,var(--glow) 0%,transparent 70%);pointer-events:none}
.hero-content{position:relative;z-index:1;max-width:820px;margin:0 auto}
.hero h1{font-size:2.8rem;font-weight:800;letter-spacing:-.02em;line-height:1.1;margin-bottom:16px;background:linear-gradient(135deg,var(--text),var(--primary));-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.hero-sub{font-size:1.15rem;color:var(--text2);margin-bottom:6px}
.hero-meta{font-size:.95rem;color:var(--text2)}
.diff-badge{display:inline-block;padding:4px 14px;border-radius:20px;font-size:.8rem;font-weight:700;color:#fff;background:var(--primary);margin-top:12px}
.cat-badge{display:inline-block;padding:4px 14px;border-radius:20px;font-size:.8rem;font-weight:600;color:var(--text2);background:var(--surface2);border:1px solid var(--border2);margin:8px 4px 0}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:16px;margin:32px auto 0;max-width:680px}
.stat-card{background:var(--surface);border:1px solid var(--border2);border-radius:12px;padding:20px;text-align:center}
.stat-num{font-size:2rem;font-weight:800;color:var(--text)}
.stat-label{font-size:.82rem;color:var(--text2);margin-top:4px}
/* layout */
.container{max-width:1000px;margin:0 auto;padding:0 24px}
.container.narrow{max-width:900px}.container.wide{max-width:1200px}
.section{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:48px;margin:32px 0}
body.light-mode .section{box-shadow:0 1px 3px rgba(0,0,0,.06)}
.section-title{font-size:1.8rem;font-weight:700;margin-bottom:20px;display:flex;align-items:center;gap:12px;color:var(--text)}
.section-title::before{content:'';width:4px;height:32px;background:var(--primary);border-radius:2px;flex-shrink:0}
.section-title i{color:var(--primary);font-size:1.3rem}
.section-desc,.section-sub{font-size:1.05rem;color:var(--text2);line-height:1.8;margin-bottom:12px}
.subsection{margin:28px 0}
.subsection h3,.section h3{font-size:1.25rem;font-weight:700;margin:20px 0 12px;color:var(--text);display:flex;align-items:center;gap:8px}
.section h3 i{color:var(--primary);font-size:1rem}
.section h4{font-size:1.05rem;font-weight:600;margin:16px 0 8px;color:var(--text)}
.section p{color:var(--text2);margin-bottom:12px;line-height:1.8}
.section ul,.section ol{padding-left:22px;margin:8px 0 14px;color:var(--text2)}
.section ul{list-style:disc}.section ol{list-style:decimal}.section li{margin:4px 0}
html[dir=rtl] .section ul,html[dir=rtl] .section ol{padding-left:0;padding-right:22px}
.section strong{color:var(--text)}
.section blockquote{border-left:3px solid var(--primary);padding:10px 18px;margin:14px 0;background:var(--surface2);border-radius:0 8px 8px 0;color:var(--text2)}
.section figure{margin:20px 0;text-align:center}.section figure img{border-radius:10px;border:1px solid var(--border2);background:#fff}
.section figcaption{font-size:.85rem;color:var(--text2);margin-top:8px}
.section hr{border:0;border-top:1px solid var(--border2);margin:24px 0}
/* boxes */
.info-box{background:var(--surface2);border:1px solid var(--border2);border-left:3px solid var(--primary);border-radius:8px;padding:20px;margin:16px 0}
html[dir=rtl] .info-box{border-left:1px solid var(--border2);border-right:3px solid var(--primary)}
.info-box h3{font-size:1rem;font-weight:600;margin:0 0 8px;display:flex;align-items:center;gap:8px}
.info-box h3 i{color:var(--primary)}
.info-box p,.info-box li{color:var(--text2);font-size:.92rem;line-height:1.8}
.info-box p:last-child{margin-bottom:0}
.info-box.warning{border-left-color:var(--warning)}.info-box.warning h3 i{color:var(--warning)}
.info-box.success{border-left-color:var(--success)}.info-box.success h3 i{color:var(--success)}
.info-box.danger{border-left-color:var(--danger)}.info-box.danger h3 i{color:var(--danger)}
html[dir=rtl] .info-box.warning{border-right-color:var(--warning)}html[dir=rtl] .info-box.success{border-right-color:var(--success)}
/* code */
.code-block,.section pre{background:var(--code);border:1px solid var(--border2);border-radius:8px;padding:20px;margin:14px 0;overflow-x:auto;font-family:'JetBrains Mono',ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.85rem;color:#e6edf3;line-height:1.6;position:relative;white-space:pre;direction:ltr;text-align:left}
.section pre code{background:none;padding:0;color:inherit;font-size:inherit}
body.light-mode .code-block,body.light-mode .section pre{background:#1e293b;color:#e2e8f0}
.copy-btn{position:absolute;top:10px;right:10px;background:var(--surface2);border:1px solid var(--border2);color:var(--text2);padding:4px 10px;border-radius:6px;cursor:pointer;font-size:.75rem;font-family:'Inter',sans-serif;transition:all .2s}
.copy-btn:hover{border-color:var(--primary);color:var(--primary)}
code{font-family:'JetBrains Mono',ui-monospace,Menlo,monospace;background:var(--surface2);padding:2px 6px;border-radius:4px;font-size:.85em;color:var(--primary-hover)}
.kw{color:#ff7b72}.str{color:#a5d6ff}.cm{color:#8b949e}.num{color:#79c0ff}.fn{color:#d2a8ff}.type{color:#ffa657}.op{color:#ff7b72}.yk{color:#7ee787}.diag{color:#94a3b8}
/* steps, tables, toggles */
.step{display:flex;gap:16px;margin:24px 0;align-items:flex-start}
.step-num{flex-shrink:0;width:34px;height:34px;border-radius:50%;background:var(--primary);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.95rem}
.step-body{flex:1;min-width:0}.step-body h3{font-size:1.15rem;font-weight:700;margin:0 0 8px;color:var(--text)}
.dark-table,.section table{width:100%;border-collapse:collapse;margin:16px 0;border-radius:8px;overflow:hidden;display:table}
.table-wrap{overflow-x:auto;margin:16px 0}
.dark-table th,.section table th{background:var(--surface2);color:var(--text);padding:12px 16px;text-align:left;font-weight:600;font-size:.85rem;border-bottom:1px solid var(--border2)}
.dark-table td,.section table td{padding:12px 16px;color:var(--text2);font-size:.85rem;border-bottom:1px solid var(--border);vertical-align:top}
html[dir=rtl] .dark-table th,html[dir=rtl] .section table th{text-align:right}
.dark-table tr:hover,.section table tr:hover{background:rgba(255,255,255,.02)}
.solution-toggle,details.solution summary{display:block;width:100%;background:var(--surface2);border:1px solid var(--border2);color:var(--text);padding:14px 20px;border-radius:8px;cursor:pointer;font-size:.95rem;font-weight:600;font-family:inherit;transition:all .2s;text-align:left;margin-top:16px}
.solution-toggle:hover,details.solution summary:hover{border-color:var(--primary)}
.solution-toggle i{margin-right:8px;color:var(--primary);transition:transform .2s}.solution-toggle.open i{transform:rotate(90deg)}
.solution-content{display:none}.solution-content.show{display:block}
details.solution{margin:12px 0}details.solution[open] summary{border-radius:8px 8px 0 0}
details.solution>div{border:1px solid var(--border2);border-top:0;border-radius:0 0 8px 8px;padding:16px 20px;background:var(--surface)}
/* buttons */
.btn,.nav-btn{display:inline-flex;align-items:center;gap:8px;padding:10px 20px;border-radius:8px;font-size:.9rem;font-weight:600;transition:all .2s;border:1px solid transparent;cursor:pointer;font-family:inherit}
.btn-primary,.nav-btn.next{background:var(--primary);color:#fff}
.btn-primary:hover,.nav-btn.next:hover{background:var(--primary-hover);color:#fff}
.btn-outline,.nav-btn.prev{background:var(--surface2);color:var(--text2);border-color:var(--border2)}
.btn-outline:hover,.nav-btn.prev:hover{border-color:var(--primary);color:var(--primary)}
.btn-sm{padding:6px 14px;font-size:.8rem}
.page-nav{display:flex;justify-content:space-between;align-items:center;margin:40px 0 0;gap:12px;flex-wrap:wrap}
/* cards grid (courses, modules) */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px}
.modules{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px}
.card,.module-card{display:block;background:var(--surface2);border:1px solid var(--border2);border-radius:12px;padding:22px;transition:all .2s;position:relative;color:var(--text)}
.card:hover,.module-card:hover{border-color:var(--primary);transform:translateY(-3px);color:var(--text)}
body.light-mode .card,body.light-mode .module-card{background:#fff}
.module-card.locked{opacity:.55;pointer-events:none}
.mod-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:10px}
.mod-icon{width:42px;height:42px;border-radius:10px;background:var(--glow);color:var(--primary);display:flex;align-items:center;justify-content:center;font-size:1.2rem}
.mod-no{font-size:.75rem;font-weight:700;color:var(--text2);background:var(--bg);padding:4px 10px;border-radius:20px;border:1px solid var(--border2)}
.mod-title{font-size:1.1rem;font-weight:700;color:var(--text);margin-bottom:6px}
.mod-desc{font-size:.85rem;color:var(--text2);line-height:1.6}
.mod-tag,.tag{display:inline-block;margin-top:12px;font-size:.72rem;font-weight:600;padding:3px 10px;border-radius:20px;background:var(--surface);border:1px solid var(--border2);color:var(--text2);margin-right:4px}
.tag-ready{background:rgba(16,185,129,.15);color:var(--success);border-color:transparent}
.tag-soon{background:rgba(148,163,184,.15);color:var(--text2);border-color:transparent}
.tag-new{background:var(--glow);color:var(--primary);border-color:transparent}
/* misc */
.fade-up{opacity:0;transform:translateY(24px);transition:opacity .4s ease,transform .4s ease}
.fade-up.visible{opacity:1;transform:translateY(0)}
@media (prefers-reduced-motion:reduce){.fade-up{opacity:1;transform:none;transition:none}}
.footer{background:var(--footer);border-top:1px solid var(--border);margin-top:48px}
.footer-bottom{padding:20px 24px;text-align:center;color:var(--text2);font-size:.8rem}
.scroll-top{position:fixed;bottom:28px;right:28px;width:44px;height:44px;border-radius:10px;background:var(--surface);border:1px solid var(--border2);color:var(--text2);display:flex;align-items:center;justify-content:center;cursor:pointer;font-size:1rem;transition:all .2s;opacity:0;pointer-events:none;z-index:900}
.scroll-top.visible{opacity:1;pointer-events:auto}.scroll-top:hover{border-color:var(--primary);color:var(--primary)}
.toc{position:fixed;right:24px;top:100px;background:var(--surface);border:1px solid var(--border2);border-radius:10px;padding:16px;width:220px;opacity:0;transform:translateX(20px);transition:all .3s;pointer-events:none;z-index:900;max-height:calc(100vh - 140px);overflow-y:auto}
html[dir=rtl] .toc{right:auto;left:24px}
.toc.visible{opacity:1;transform:translateX(0);pointer-events:auto}
.toc h4{font-size:.8rem;font-weight:600;color:var(--text2);text-transform:uppercase;letter-spacing:.05em;margin-bottom:12px}
.toc-item{display:block;padding:5px 12px;font-size:.75rem;color:var(--text2);border-left:2px solid transparent;margin:2px 0;border-radius:0 4px 4px 0;transition:all .2s;cursor:pointer}
.toc-item:hover{color:var(--text);background:rgba(255,255,255,.03)}
.toc-item.active{color:var(--primary);border-left-color:var(--primary);background:var(--glow)}
.form-input,.form-select{width:100%;background:var(--surface2);border:1px solid var(--border2);color:var(--text);padding:10px 14px;border-radius:8px;font-family:inherit;font-size:.95rem}
.form-input:focus,.form-select:focus{outline:none;border-color:var(--primary)}
.text-muted{color:var(--text2)}.text-center{text-align:center}.mt-1{margin-top:8px}.mt-2{margin-top:16px}.mt-3{margin-top:24px}.mb-2{margin-bottom:16px}
.progress-track{height:6px;background:var(--surface2);border-radius:3px;overflow:hidden;border:1px solid var(--border2)}.progress-fill{height:100%;background:var(--success);border-radius:3px}
@media(max-width:1400px){.toc{display:none}}
@media(max-width:768px){.hero h1{font-size:2rem}.hero{padding:56px 20px 40px}.section{padding:24px 16px}.nav-links{display:none}.hamburger{display:block}.page-nav{flex-direction:column;gap:12px}.dark-table,.section table{font-size:.75rem}.dark-table th,.dark-table td,.section table th,.section table td{padding:8px}}
@media print{.navbar,.mobile-menu,.scroll-top,.toc,.theme-toggle{display:none!important}.hero{margin-top:0}body{background:#fff;color:#000}.section{border:0;box-shadow:none}}