/* ============================================================
   SECTION PRIMITIVES
   ============================================================ */
.section{padding:var(--space-16) 0}
.section-alt{background:var(--bg-1);border-top:1px solid var(--border);border-bottom:1px solid var(--border)}
.section-head{max-width:640px;margin-bottom:var(--space-6)}
.section-kicker{color:var(--accent);font-size:var(--text-sm);font-weight:500;margin-bottom:var(--space-1);display:block}
.section-title{font-size:var(--text-2xl)}
.section-desc{color:var(--fg-1);margin-top:var(--space-2);font-size:var(--text-md)}
.section-foot{margin-top:var(--space-6);text-align:center}
.section-title-sm{font-size:var(--text-xl)}

/* ============================================================
   PRIMITIVES — buttons, cards, tags
   ============================================================ */
.btn{
  display:inline-flex;align-items:center;gap:.5rem;justify-content:center;
  padding:.85rem 1.6rem;border-radius:var(--radius-md);font-size:var(--text-sm);font-weight:600;
  border:1px solid transparent;cursor:pointer;transition:transform var(--dur-fast) var(--ease-out),background var(--dur-fast),border-color var(--dur-fast);
}
.btn:active{transform:scale(.97)}
.btn-primary{background:var(--accent);color:var(--bg-0)}
.btn-primary:hover{background:var(--accent-strong)}
.btn-ghost{background:transparent;border-color:var(--border-strong);color:var(--fg-0)}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent)}

.card{
  background:var(--bg-1);border:1px solid var(--border);border-radius:var(--radius-lg);
  padding:var(--space-4);box-shadow:var(--card-shadow);
  transition:border-color var(--dur-fast) var(--ease-out),transform var(--dur-fast) var(--ease-out);
}
.card:hover{border-color:var(--border-strong)}

.tag{
  display:inline-block;font-size:var(--text-xs);color:var(--fg-1);
  border:1px solid var(--border);border-radius:999px;padding:.25rem .75rem;
}
.tag-soon{background:var(--accent-soft);color:var(--accent);border-color:transparent}

.eyebrow-meta{font-size:var(--text-xs);color:var(--fg-2)}

/* ============================================================
   HEADER / NAV
   ============================================================ */
.site-header{
  position:sticky;top:0;z-index:100;background:color-mix(in srgb, var(--bg-0) 85%, transparent);
  backdrop-filter:blur(10px);border-bottom:1px solid var(--border);
}
.site-header .container{display:flex;align-items:center;justify-content:space-between;height:72px}
.logo{font-family:var(--font-display);font-weight:700;font-size:var(--text-md)}
.logo span{color:var(--accent)}
.nav-main{display:flex;align-items:center;gap:var(--space-4)}
.nav-links{display:flex;gap:var(--space-3)}
.nav-links a{font-size:var(--text-sm);color:var(--fg-1);padding:.4rem 0;position:relative}
.nav-links a:hover{color:var(--fg-0)}
.nav-links a::after{content:"";position:absolute;inset-inline:0;bottom:-2px;height:1px;background:var(--accent);transform:scaleX(0);transition:transform var(--dur-fast) var(--ease-out)}
.nav-links a:hover::after{transform:scaleX(1)}
.nav-actions{display:flex;align-items:center;gap:var(--space-2)}
.icon-btn{
  width:38px;height:38px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg-1);
  display:flex;align-items:center;justify-content:center;cursor:pointer;color:var(--fg-1);transition:border-color var(--dur-fast),color var(--dur-fast);
}
.icon-btn:hover{border-color:var(--accent);color:var(--accent)}
.search-trigger{
  display:flex;align-items:center;gap:.6rem;height:38px;padding:0 .9rem;border-radius:var(--radius-sm);
  border:1px solid var(--border);background:var(--bg-1);color:var(--fg-2);font-size:var(--text-xs);cursor:pointer;
}
.search-trigger kbd{font-family:var(--font-mono);border:1px solid var(--border);border-radius:4px;padding:0 .35rem;font-size:.7rem}
.mobile-nav-toggle{display:none}

/* mobile drawer */
.mobile-drawer{
  position:fixed;inset:0;z-index:150;background:var(--bg-0);transform:translateX(100%);
  transition:transform var(--dur-med) var(--ease-in-out);padding:var(--space-4);visibility:hidden;
}
.mobile-drawer.open{visibility:visible}
html[dir="rtl"] .mobile-drawer{transform:translateX(-100%)}
.mobile-drawer.open{transform:translateX(0)}
/* html[dir="rtl"] .mobile-drawer above has higher specificity (0,2,1) than
   .mobile-drawer.open (0,2,0), so it always wins over the open-state rule
   in RTL regardless of source order. This rule matches that specificity
   exactly so the open state correctly overrides the closed RTL transform. */
html[dir="rtl"] .mobile-drawer.open{transform:translateX(0)}
.mobile-drawer .container{padding:0}
.mobile-drawer-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:var(--space-6)}
.mobile-drawer nav ul{display:flex;flex-direction:column;gap:var(--space-3)}
.mobile-drawer nav a{font-size:var(--text-lg);font-family:var(--font-display);font-weight:600}

/* ============================================================
   COMMAND PALETTE
   ============================================================ */
.palette-backdrop{
  position:fixed;inset:0;background:var(--overlay);backdrop-filter:blur(2px);
  z-index:300;display:none;align-items:flex-start;justify-content:center;padding-top:12vh;
}
.palette-backdrop.open{display:flex}
.palette{
  width:min(560px,92vw);background:var(--bg-1);border:1px solid var(--border-strong);border-radius:var(--radius-lg);
  box-shadow:var(--shadow);overflow:hidden;
}
.palette-input-row{display:flex;align-items:center;gap:.75rem;padding:var(--space-3);border-bottom:1px solid var(--border)}
.palette-input-row input{flex:1;background:transparent;border:none;outline:none;font-size:var(--text-md);color:var(--fg-0)}
.palette-results{max-height:320px;overflow-y:auto;padding:.5rem}
.palette-result{display:flex;flex-direction:column;padding:.75rem 1rem;border-radius:var(--radius-sm);cursor:pointer}
.palette-result:hover,.palette-result.active{background:var(--bg-2)}
.palette-result strong{font-size:var(--text-sm)}
.palette-result span{font-size:var(--text-xs);color:var(--fg-2)}
.palette-empty{padding:var(--space-4);text-align:center;color:var(--fg-2);font-size:var(--text-sm)}
.palette-hint{padding:.6rem var(--space-3);border-top:1px solid var(--border);font-size:var(--text-xs);color:var(--fg-2);display:flex;gap:var(--space-3)}

/* ============================================================
   HERO
   ============================================================ */
.hero{position:relative;padding:var(--space-16) 0 var(--space-12);overflow:hidden}
.hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:var(--space-8);align-items:center}
.hero-eyebrow{color:var(--accent);font-size:var(--text-sm);font-weight:500;margin-bottom:var(--space-2);display:block}
.hero-title{font-size:var(--text-4xl);letter-spacing:-.02em}
.hero-sub{margin-top:var(--space-3);font-size:var(--text-md);color:var(--fg-1);max-width:52ch}
.hero-ctas{display:flex;gap:var(--space-2);margin-top:var(--space-4)}
.hero-meta{display:flex;flex-wrap:wrap;gap:.5rem;margin-top:var(--space-4)}
.hero-canvas-wrap{position:relative;aspect-ratio:1/1;border-radius:var(--radius-lg);overflow:hidden;background:var(--bg-1);border:1px solid var(--border)}
.hero-canvas-wrap canvas{width:100%;height:100%;display:block}
.hero-canvas-fallback{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;color:var(--fg-2);font-size:var(--text-sm)}

/* ============================================================
   GRIDS / CARDS
   ============================================================ */
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:var(--space-4)}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:var(--space-4)}

.project-card .project-cover{
  aspect-ratio:16/10;border-radius:var(--radius-md);background:linear-gradient(135deg,var(--bg-2),var(--bg-3));
  margin-bottom:var(--space-3);display:flex;align-items:center;justify-content:center;color:var(--fg-2);font-size:var(--text-xs);
}
.project-card h3{font-size:var(--text-md);margin-bottom:.4rem}
.project-card p{color:var(--fg-1);font-size:var(--text-sm)}
.project-top-row{display:flex;justify-content:space-between;align-items:baseline;gap:var(--space-2)}
.project-year{font-size:var(--text-xs);color:var(--fg-2);font-family:var(--font-mono)}
.project-meta{display:flex;flex-wrap:wrap;gap:.4rem;margin-top:var(--space-2)}
.project-status{margin-top:var(--space-3);padding-top:var(--space-3);border-top:1px solid var(--border);font-size:var(--text-xs);color:var(--fg-2)}
.project-status a:hover{color:var(--accent)}

.capability-card{display:flex;flex-direction:column;gap:.6rem}
.capability-card h3{font-size:var(--text-base)}
.capability-card p{color:var(--fg-1);font-size:var(--text-sm)}

.lab-card{padding:0;overflow:hidden}
.lab-card-canvas{aspect-ratio:4/3;background:var(--bg-2)}
.lab-card-canvas canvas{width:100%;height:100%;display:block}
.lab-card-body{padding:var(--space-3)}
.lab-card-body h3{font-size:var(--text-base);margin-bottom:.3rem}
.lab-card-control{display:flex;align-items:center;gap:.6rem;margin-top:var(--space-2)}
.lab-card-control label{font-size:var(--text-xs);color:var(--fg-2);white-space:nowrap}
.lab-card-control input[type=range]{flex:1;accent-color:var(--accent)}
.lab-card-control output{font-size:var(--text-xs);font-family:var(--font-mono);color:var(--fg-1);min-width:1.6em;text-align:left;direction:ltr}

.article-card h3{font-size:var(--text-base);margin-bottom:.4rem}
.article-card p{color:var(--fg-1);font-size:var(--text-sm)}
.article-card .eyebrow-meta{margin-top:var(--space-2);display:block}

/* ============================================================
   TOOLS
   ============================================================ */
.tool-live{padding:0;overflow:hidden}
.tool-live-body{padding:var(--space-4)}
.tool-live-body h3{font-size:var(--text-base);margin-bottom:var(--space-2)}
.tool-field{display:flex;flex-direction:column;gap:.35rem;margin-bottom:var(--space-2)}
.tool-field label{font-size:var(--text-xs);color:var(--fg-2)}
.tool-field input{
  background:var(--bg-2);border:1px solid var(--border);border-radius:var(--radius-sm);
  padding:.6rem .8rem;direction:ltr;text-align:left;font-family:var(--font-mono);
  transition:border-color var(--dur-fast) var(--ease-out);
}
.tool-field input:focus-visible{border-color:var(--accent)}
.tool-output{
  display:flex;align-items:center;justify-content:space-between;background:var(--bg-2);
  border:1px solid var(--border);border-radius:var(--radius-sm);padding:.6rem .8rem;margin-top:var(--space-2);
}
.tool-output .mono{font-size:var(--text-sm);color:var(--accent-code)}
.copy-btn{
  border:1px solid var(--border);background:transparent;border-radius:var(--radius-sm);
  padding:.35rem .7rem;font-size:var(--text-xs);cursor:pointer;color:var(--fg-1);
}
.copy-btn:hover{border-color:var(--accent);color:var(--accent)}
.swatch{width:20px;height:20px;border-radius:5px;border:1px solid var(--border);flex-shrink:0}

/* ============================================================
   LEARNING HUB — dense, list-like, contrasts with the airy Lab section
   ============================================================ */
.learn-list{display:grid;grid-template-columns:repeat(2,1fr);gap:1px;background:var(--border);border:1px solid var(--border);border-radius:var(--radius-lg);overflow:hidden}
.learn-row{background:var(--bg-1);padding:var(--space-3) var(--space-4);display:flex;justify-content:space-between;align-items:center;gap:var(--space-2)}
.learn-row-title{font-size:var(--text-base);font-weight:600}
.learn-row-desc{color:var(--fg-1);font-size:var(--text-sm);margin-top:.2rem}
.learn-row-count{font-size:var(--text-xs);color:var(--fg-2);white-space:nowrap;font-family:var(--font-mono)}
.learn-path{display:flex;flex-direction:column;gap:var(--space-3)}
.learn-path-row{display:flex;align-items:center;flex-wrap:wrap;gap:var(--space-2)}
.learn-path-arrow{color:var(--fg-2)}

/* ============================================================
   PROJECTS PAGE — single featured project
   Built from the existing .card + .about-strip primitives rather
   than a new layout; these rules only adjust minor spacing.
   ============================================================ */
.project-feature h2{font-size:var(--text-lg);margin-bottom:var(--space-1)}
.project-feature p{margin-top:var(--space-2)}
.project-feature .btn{margin-top:var(--space-4)}
.project-feature .project-cover{margin-bottom:0}
/* ============================================================
   LAB PAGE — featured experiment
   ============================================================ */
.lab-feature{display:flex;flex-direction:column;align-items:center;text-align:center;gap:var(--space-3)}
.lab-feature .hero-canvas-wrap{width:100%;max-width:480px}
.lab-feature h2{font-size:var(--text-lg)}
.hex-swatch-row{display:flex;align-items:center;gap:.6rem}

.section-title-sm{font-size:var(--text-xl)}
.learn-path{display:flex;flex-direction:column;gap:var(--space-3)}
.learn-path-row{display:flex;flex-wrap:wrap;align-items:center;gap:.6rem}
.learn-path-arrow{color:var(--fg-2);font-size:var(--text-sm)}

/* ============================================================
   CONTENT PAGES — shared visual system
   Used by /learn/{track}/{lesson}/ and /articles/{slug}/.
   Everything below is built from existing tokens only.
   ============================================================ */
.content-lead{font-size:var(--text-md);color:var(--fg-1);margin-top:var(--space-2)}
.content-hero{padding-bottom:var(--space-6);margin-bottom:var(--space-2);border-bottom:1px solid var(--border)}
.content-meta{display:flex;gap:var(--space-2);flex-wrap:wrap;margin-top:var(--space-2)}

.content-body{max-width:720px;margin:var(--space-6) 0 0;overflow-x:hidden}
.content-body{counter-reset:content-section-counter;}
.content-body>p{color:var(--fg-1);margin-top:var(--space-3);line-height:1.9}
.content-body>ul,.content-body>ol{margin-top:var(--space-3);padding-inline-start:1.4em;color:var(--fg-1);line-height:1.9}
.content-body>ul>li,.content-body>ol>li{margin-top:.4rem}
.content-body strong{color:var(--fg-0);font-weight:600}
.content-body pre{
  background:var(--bg-2);border:1px solid var(--border);border-radius:var(--radius-md);
  padding:var(--space-3);margin-top:var(--space-3);overflow-x:auto;direction:ltr;text-align:left;
}
.content-body pre code{font-family:var(--font-mono);font-size:var(--text-sm);color:var(--fg-0);white-space:pre}
.content-body :not(pre)>code{
  font-family:var(--font-mono);font-size:.9em;background:var(--bg-2);
  padding:.15em .4em;border-radius:4px;color:var(--accent-code);direction:ltr;unicode-bidi:isolate;
}

/* ============================================================
   "در این درس می‌خوانید" — objectives as a roadmap card.
   Numbered, clickable rows rather than a plain bulleted list.
   ============================================================ */
.content-callout{
  background:var(--bg-1);border:1px solid var(--border);border-inline-start:3px solid var(--accent);
  border-radius:var(--radius-md);padding:var(--space-3) var(--space-4);margin-top:var(--space-4);
}
.content-callout h3{margin-top:0;font-size:var(--text-base)}
.content-callout ul{margin-top:var(--space-2)}

.content-objectives{
  background:var(--bg-1);border:1px solid var(--border);border-radius:var(--radius-lg);
  padding:var(--space-4);margin-top:var(--space-4);box-shadow:var(--card-shadow);
}
.content-objectives h3{margin-top:0;font-size:var(--text-base);color:var(--fg-0)}
.content-objectives ul{
  list-style:none;margin-top:var(--space-2);padding-inline-start:0;
  counter-reset:objective-counter;
}
.content-objectives li{counter-increment:objective-counter;margin-top:0;border-top:1px solid var(--border)}
.content-objectives li:first-child{border-top:none}
.content-objective-link{
  display:flex;align-items:baseline;gap:var(--space-2);
  padding:.6rem .3rem;color:var(--fg-1);text-decoration:none;
  border-radius:var(--radius-sm);transition:background var(--dur-fast) var(--ease-out),color var(--dur-fast) var(--ease-out),padding-inline-start var(--dur-fast) var(--ease-out);
}
.content-objective-link::before{
  content:counter(objective-counter,decimal-leading-zero);
  font-family:var(--font-mono);font-size:var(--text-xs);color:var(--accent);flex-shrink:0;
}
.content-objective-link:hover,.content-objective-link:focus-visible{
  color:var(--accent);background:var(--accent-soft);padding-inline-start:.6rem;
}

/* ============================================================
   Accordion content cards — built on native <details>/<summary>
   so keyboard focus, Enter/Space toggling, and aria-expanded all
   come for free from the browser with zero JavaScript.
   ============================================================ */
.content-section{
  counter-increment:content-section-counter;
  border:1px solid var(--border);border-radius:var(--radius-lg);
  margin-top:var(--space-4);background:var(--bg-1);box-shadow:var(--card-shadow);
  overflow:hidden;
  transition:border-color var(--dur-fast) var(--ease-out),box-shadow var(--dur-fast) var(--ease-out);
}
.content-section:hover{border-color:var(--border-strong)}
.content-section[open]{border-color:var(--accent-soft)}

.content-section-toggle{
  display:flex;align-items:center;gap:var(--space-3);min-width:0;
  padding:var(--space-4);cursor:pointer;list-style:none;
  transition:background var(--dur-fast) var(--ease-out);
}
.content-section-toggle::-webkit-details-marker{display:none}
.content-section-toggle::marker{content:""}
.content-section:hover .content-section-toggle{background:var(--bg-2)}

.content-section-number{
  order:-1;flex-shrink:0;font-family:var(--font-mono);font-size:var(--text-sm);
  color:var(--fg-2);min-width:2.2ch;
}
.content-section-number::before{content:counter(content-section-counter,decimal-leading-zero)}

.content-section-toggle h2{
  flex:1;min-width:0;overflow-wrap:anywhere;font-size:var(--text-lg);margin:0;color:var(--fg-0);
  transition:color var(--dur-fast) var(--ease-out);
}
.content-section:hover .content-section-toggle h2{color:var(--accent)}
.content-section[open] .content-section-toggle h2{color:var(--accent)}
.content-section-toggle:focus-visible{outline:2px solid var(--accent);outline-offset:-2px}

.content-section-indicator{
  order:1;flex-shrink:0;width:28px;height:28px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  border:1px solid var(--border-strong);color:var(--accent);
  font-family:var(--font-mono);font-size:var(--text-md);line-height:1;
  transition:background var(--dur-fast) var(--ease-out),border-color var(--dur-fast) var(--ease-out),transform var(--dur-fast) var(--ease-out);
}
.content-section-indicator::before{content:"+"}
.content-section[open] .content-section-indicator::before{content:"−"}
.content-section:hover .content-section-indicator,
.content-section[open] .content-section-indicator{
  border-color:var(--accent);background:var(--accent-soft);
}

.content-section[open] .content-section-toggle{border-bottom:1px solid var(--border)}

/* Fallback for browsers that don't auto-reveal a closed <details> when
   navigating to a fragment target inside it: since every accordion id
   sits on the .content-section itself, :target lets pure CSS force the
   same "open" appearance the native [open] state produces — no JS. */
.content-section:target{border-color:var(--accent-soft)}
.content-section:target>.content-section-toggle{border-bottom:1px solid var(--border)}
.content-section:target>.content-section-toggle h2{color:var(--accent)}
.content-section:target>.content-section-toggle .content-section-indicator{border-color:var(--accent);background:var(--accent-soft)}
.content-section:target>.content-section-toggle .content-section-indicator::before{content:"−"}
.content-section:target>.content-section-body{display:block}

.content-section-body{padding:var(--space-4)}
.content-section-body>p:first-child{margin-top:0}
.content-section-body h3{font-size:var(--text-base);margin-top:var(--space-5);margin-bottom:var(--space-1)}
.content-section-body p{color:var(--fg-1);margin-top:var(--space-3);line-height:1.9}
.content-section-body ul,.content-section-body ol{margin-top:var(--space-3);padding-inline-start:1.4em;color:var(--fg-1);line-height:1.9}
.content-section-body li{margin-top:.4rem}
.content-section-body strong{color:var(--fg-0);font-weight:600}
.content-section-body pre{
  background:var(--bg-2);border:1px solid var(--border);border-radius:var(--radius-md);
  padding:var(--space-3);margin-top:var(--space-3);overflow-x:auto;direction:ltr;text-align:left;
}
.content-section-body pre code{font-family:var(--font-mono);font-size:var(--text-sm);color:var(--fg-0);white-space:pre}
.content-section-body :not(pre)>code{
  font-family:var(--font-mono);font-size:.9em;background:var(--bg-2);
  padding:.15em .4em;border-radius:4px;color:var(--accent-code);direction:ltr;unicode-bidi:isolate;
}

@media(max-width:640px){
  .content-section-toggle{padding:var(--space-3)}
  .content-section-body{padding:var(--space-3)}
  .content-section-toggle h2{font-size:var(--text-base)}
  .content-section-indicator{width:24px;height:24px;font-size:var(--text-base)}
}

@media(prefers-reduced-motion:reduce){
  .content-section,.content-section-toggle,.content-section-toggle h2,
  .content-section-indicator,.content-objective-link{transition:none}
}

.content-nav{
  margin-top:var(--space-8);padding-top:var(--space-6);border-top:1px solid var(--border);
  display:flex;justify-content:space-between;gap:var(--space-3);flex-wrap:wrap;max-width:720px;
}
.content-nav a{color:var(--accent);font-size:var(--text-sm)}
.content-nav a:hover{color:var(--accent-strong)}

/* ============================================================
   STACK
   ============================================================ */
.stack-groups{display:grid;grid-template-columns:repeat(3,1fr);gap:var(--space-4)}
.stack-group h4{font-size:var(--text-sm);color:var(--fg-2);font-weight:500;margin-bottom:var(--space-2)}
.stack-group ul{display:flex;flex-wrap:wrap;gap:.5rem}
.stack-group li{font-size:var(--text-sm);border:1px solid var(--border);border-radius:999px;padding:.3rem .9rem}

/* ============================================================
   ABOUT SHORT
   ============================================================ */
.about-strip{display:grid;grid-template-columns:.8fr 1.2fr;gap:var(--space-6);align-items:center}
.about-strip p{color:var(--fg-1);font-size:var(--text-md)}

/* ============================================================
   FINAL CTA
   ============================================================ */
.final-cta{
  background:var(--bg-1);border:1px solid var(--border);border-radius:var(--radius-lg);
  padding:var(--space-8);text-align:center;box-shadow:var(--card-shadow);
}
.final-cta h2{font-size:var(--text-2xl)}
.final-cta p{color:var(--fg-1);margin-top:var(--space-2)}
.final-cta .hero-ctas{justify-content:center;margin-top:var(--space-4)}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer{border-top:1px solid var(--border);padding:var(--space-6) 0;color:var(--fg-2);font-size:var(--text-sm)}
.footer-row{display:flex;justify-content:space-between;flex-wrap:wrap;gap:var(--space-2)}
.footer-links{display:flex;gap:var(--space-3)}
.footer-links a:hover{color:var(--fg-0)}