/* ==========================================================================
   Ertunç Özbay — Engineering Studio, Hardware Lab & Open-Source Hub
   Multi-Theme System:
   1. 🎨 Colorful Studio (DEFAULT — Bright, Vibrant, Multi-Color Engineering UI)
   2. 🌈 Cyber Neon (Rich Indigo/Violet Synthwave Night Theme)
   3. 📐 Blueprint Lab (Crisp Technical Paper & Cobalt Schematic Theme)
   Plain CSS • Accessible • Responsive • Copyable Code & Command Blocks
   ========================================================================== */

:root,
[data-theme="colorful"] {
  /* 1. DEFAULT: Vibrant Colorful Studio (Bright, Energetic, Non-Dark!) */
  --bg-primary: #f3f6fc;
  --bg-secondary: #eaf0fa;
  --bg-card: #ffffff;
  --bg-card-hover: #f8faff;
  --bg-code: #0f172a;
  --bg-header: rgba(255, 255, 255, 0.92);

  /* Crisp Structural Borders */
  --border-subtle: #d8e2f0;
  --border-strong: #b8c7de;
  --border-accent: #6366f1;

  /* High-Contrast Typography on Bright Canvas */
  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #5b6b82;

  /* Vivid Multi-Color Accents */
  --accent-amber: #ea580c;
  --accent-amber-soft: rgba(234, 88, 12, 0.12);
  --accent-teal: #0284c7;
  --accent-teal-soft: rgba(2, 132, 199, 0.12);
  --accent-emerald: #059669;
  --accent-emerald-soft: rgba(5, 150, 105, 0.12);
  --accent-magenta: #db2777;
  --accent-magenta-soft: rgba(219, 39, 119, 0.12);
  --accent-violet: #6d28d9;
  --accent-violet-soft: rgba(109, 40, 217, 0.12);
  --accent-coral: #e11d48;
  --accent-coral-soft: rgba(225, 29, 72, 0.12);
  --accent-blue: #2563eb;

  /* Colorful Studio Gradients */
  --grad-hero: linear-gradient(135deg, #ffffff 0%, #eef2ff 45%, #fdf2f8 78%, #fff7ed 100%);
  --grad-brand: linear-gradient(135deg, #ff512f 0%, #dd2476 50%, #4f46e5 100%);
  --grad-title: linear-gradient(90deg, #0f172a 0%, #4f46e5 38%, #db2777 72%, #ea580c 100%);
  --body-bg-image:
    radial-gradient(circle at 8% 12%, rgba(56, 189, 248, 0.22), transparent 36%),
    radial-gradient(circle at 92% 10%, rgba(244, 114, 182, 0.22), transparent 36%),
    radial-gradient(circle at 85% 85%, rgba(251, 146, 60, 0.18), transparent 38%),
    radial-gradient(circle at 15% 88%, rgba(52, 211, 153, 0.18), transparent 38%),
    radial-gradient(rgba(99, 102, 241, 0.10) 1px, transparent 1px);

  --shadow-panel: 0 14px 36px rgba(30, 41, 59, 0.09);
  --shadow-card: 0 8px 24px rgba(30, 41, 59, 0.07);

  /* Typography & Layout Tokens */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --max-width: 1140px;
  --max-reading-width: 75ch;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
}

/* 2. 🌈 Cyber Neon Theme (Rich Violet-Indigo Synthwave — Never Flat Gray!) */
[data-theme="neon"] {
  --bg-primary: #131129;
  --bg-secondary: #1b1738;
  --bg-card: #221d46;
  --bg-card-hover: #2b2458;
  --bg-code: #0b091b;
  --bg-header: rgba(19, 17, 41, 0.90);

  --border-subtle: #38306b;
  --border-strong: #524699;
  --border-accent: #f472b6;

  --text-primary: #f8fafc;
  --text-secondary: #dcd7fe;
  --text-muted: #a59de6;

  --accent-amber: #fbbf24;
  --accent-amber-soft: rgba(251, 191, 36, 0.18);
  --accent-teal: #22d3ee;
  --accent-teal-soft: rgba(34, 211, 238, 0.18);
  --accent-emerald: #34d399;
  --accent-emerald-soft: rgba(52, 211, 153, 0.18);
  --accent-magenta: #f472b6;
  --accent-magenta-soft: rgba(244, 114, 182, 0.18);
  --accent-violet: #c084fc;
  --accent-violet-soft: rgba(192, 132, 252, 0.18);
  --accent-coral: #fb7185;
  --accent-coral-soft: rgba(251, 113, 133, 0.18);
  --accent-blue: #60a5fa;

  --grad-hero: linear-gradient(135deg, rgba(40, 31, 84, 0.96) 0%, rgba(59, 25, 84, 0.94) 55%, rgba(22, 46, 79, 0.94) 100%);
  --grad-title: linear-gradient(90deg, #ffffff 0%, #22d3ee 35%, #f472b6 70%, #fbbf24 100%);
  --body-bg-image:
    radial-gradient(circle at 12% 12%, rgba(236, 72, 153, 0.24), transparent 36%),
    radial-gradient(circle at 88% 15%, rgba(6, 182, 212, 0.22), transparent 36%),
    radial-gradient(circle at 50% 85%, rgba(139, 92, 246, 0.22), transparent 42%),
    radial-gradient(rgba(192, 132, 252, 0.12) 1px, transparent 1px);

  --shadow-panel: 0 16px 40px rgba(5, 3, 20, 0.55);
  --shadow-card: 0 10px 28px rgba(5, 3, 20, 0.42);
}

/* 3. 📐 Blueprint Lab Theme (Warm Technical Paper & Cobalt Schematic) */
[data-theme="blueprint"] {
  --bg-primary: #fdfbf7;
  --bg-secondary: #f3efe6;
  --bg-card: #ffffff;
  --bg-card-hover: #f7f4ec;
  --bg-code: #172554;
  --bg-header: rgba(253, 251, 247, 0.94);

  --border-subtle: #d6d0c2;
  --border-strong: #aca391;
  --border-accent: #1d4ed8;

  --text-primary: #172554;
  --text-secondary: #334155;
  --text-muted: #64748b;

  --accent-amber: #d97706;
  --accent-amber-soft: rgba(217, 119, 6, 0.14);
  --accent-teal: #1d4ed8;
  --accent-teal-soft: rgba(29, 78, 216, 0.12);
  --accent-emerald: #047857;
  --accent-emerald-soft: rgba(4, 120, 87, 0.12);
  --accent-magenta: #be185d;
  --accent-magenta-soft: rgba(190, 24, 93, 0.12);
  --accent-violet: #4338ca;
  --accent-violet-soft: rgba(67, 56, 202, 0.12);
  --accent-coral: #b91c1c;
  --accent-coral-soft: rgba(185, 28, 28, 0.12);
  --accent-blue: #1d4ed8;

  --grad-hero: linear-gradient(135deg, #ffffff 0%, #eff6ff 55%, #fef3c7 100%);
  --grad-title: linear-gradient(90deg, #172554 0%, #1d4ed8 50%, #d97706 100%);
  --body-bg-image:
    linear-gradient(rgba(29, 78, 216, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(29, 78, 216, 0.05) 1px, transparent 1px);

  --shadow-panel: 0 10px 28px rgba(23, 37, 84, 0.08);
  --shadow-card: 0 6px 18px rgba(23, 37, 84, 0.06);
}

/* Base Reset */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 100%;
  scroll-behavior: smooth;
  background-color: var(--bg-primary);
  color: var(--text-primary);
}

body {
  margin: 0;
  font-family: var(--font-sans);
  line-height: 1.68;
  background-color: var(--bg-primary);
  background-image: var(--body-bg-image);
  background-size: 100% 100%, 100% 100%, 100% 100%, 100% 100%, 26px 26px;
  background-attachment: fixed;
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color 0.2s ease, color 0.2s ease;
}

[data-theme="blueprint"] body {
  background-size: 24px 24px, 24px 24px;
}

/* Accessibility: Skip Link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  z-index: 1000;
  background: var(--grad-brand);
  color: #ffffff;
  padding: 0.65rem 1.1rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  text-decoration: none;
  box-shadow: var(--shadow-panel);
}

.skip-link:focus {
  top: 1rem;
  outline: 3px solid var(--accent-teal);
  outline-offset: 2px;
}

/* Focus States */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--accent-teal);
  outline-offset: 3px;
  border-radius: 4px;
}

/* Typography Hierarchy */
h1, h2, h3, h4 {
  color: var(--text-primary);
  line-height: 1.24;
  margin-top: 0;
  font-weight: 800;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(1.95rem, 3.6vw, 2.75rem);
  margin-bottom: 1rem;
}

.gradient-title {
  background: var(--grad-title);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
}

h2 {
  font-size: clamp(1.38rem, 2.5vw, 1.85rem);
  margin-bottom: 0.85rem;
}

h3 {
  font-size: 1.22rem;
  margin-bottom: 0.55rem;
}

p {
  margin-top: 0;
  margin-bottom: 1.15rem;
  color: var(--text-secondary);
}

ul, ol {
  margin-top: 0;
  margin-bottom: 1.15rem;
  padding-left: 1.35rem;
  color: var(--text-secondary);
}

li {
  margin-bottom: 0.45rem;
}

strong {
  color: var(--text-primary);
  font-weight: 700;
}

code, pre {
  font-family: var(--font-mono);
  font-size: 0.89em;
}

code {
  background-color: var(--accent-teal-soft);
  color: var(--accent-teal);
  padding: 0.15rem 0.45rem;
  border-radius: 5px;
  border: 1px solid rgba(2, 132, 199, 0.22);
  font-weight: 600;
}

pre {
  background-color: var(--bg-code);
  color: #f8fafc;
  padding: 1.15rem 1.25rem;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  border: 1px solid var(--border-subtle);
  overflow-x: auto;
  line-height: 1.55;
  margin: 0;
}

pre code {
  background: none;
  border: none;
  padding: 0;
  color: #e2e8f0;
  font-weight: 400;
}

/* Interactive Code & Terminal Window Component */
.code-window {
  margin: 1.15rem 0 1.65rem;
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-strong);
}

.code-window-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  background: linear-gradient(90deg, #1e293b 0%, #0f172a 100%);
  color: #f8fafc;
  padding: 0.55rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.code-window-title {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  color: #38bdf8;
}

.code-dots {
  display: inline-flex;
  gap: 0.35rem;
}

.code-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
}

.code-dot.red { background: #fb7185; }
.code-dot.amber { background: #fbbf24; }
.code-dot.green { background: #34d399; }

.copy-code-btn {
  background: rgba(255, 255, 255, 0.1);
  color: #f8fafc;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 6px;
  padding: 0.25rem 0.65rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.15s ease;
}

.copy-code-btn:hover {
  background: #38bdf8;
  color: #0f172a;
  border-color: #38bdf8;
}

a {
  color: var(--accent-teal);
  text-decoration: underline;
  text-underline-offset: 0.22em;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--accent-magenta);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Layout Containers */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.35rem;
}

.reading-width {
  max-width: var(--max-reading-width);
}

main {
  flex: 1;
  padding: 2.35rem 0 4.5rem;
}

/* Header, Navigation & Always-Visible Theme Switcher */
.site-header {
  background-color: var(--bg-header);
  border-bottom: 1px solid var(--border-subtle);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(14px);
  box-shadow: 0 4px 16px rgba(15, 23, 42, 0.05);
}

.site-header::before {
  content: "";
  display: block;
  height: 4px;
  width: 100%;
  background: linear-gradient(90deg, #06b6d4 0%, #6366f1 28%, #ec4899 58%, #f59e0b 82%, #10b981 100%);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 4.5rem;
  gap: 0.85rem;
  flex-wrap: wrap;
  padding-top: 0.4rem;
  padding-bottom: 0.4rem;
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 800;
  font-size: 1.08rem;
}

.site-brand:hover {
  color: var(--accent-teal);
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.35rem;
  height: 2.35rem;
  background: var(--grad-brand);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 800;
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(221, 36, 118, 0.35);
}

.brand-subtitle {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--accent-magenta);
}

/* Header Controls Wrapper (Nav + Prominent Theme Switcher) */
.header-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* Prominent Multi-Theme Switcher Pill Bar */
.theme-switcher {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-strong);
  padding: 0.22rem;
  border-radius: 999px;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.06);
}

.theme-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.32rem 0.68rem;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.15s ease;
}

.theme-btn:hover {
  color: var(--text-primary);
}

.theme-btn[aria-pressed="true"] {
  background: var(--grad-brand);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(221, 36, 118, 0.35);
}

/* Mobile Navigation Button */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.4rem;
  background-color: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  padding: 0.45rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  cursor: pointer;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list li {
  margin: 0;
}

.nav-link {
  display: inline-block;
  padding: 0.42rem 0.8rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.94rem;
  font-weight: 650;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: all 0.15s ease;
}

.nav-link:hover {
  color: var(--text-primary);
  background-color: var(--bg-secondary);
  border-color: var(--border-subtle);
}

.nav-link[aria-current="page"] {
  color: var(--accent-violet);
  background-color: var(--accent-violet-soft);
  border-color: rgba(109, 40, 217, 0.35);
  font-weight: 750;
}

[data-theme="neon"] .nav-link[aria-current="page"] {
  color: #ffffff;
  background: linear-gradient(135deg, rgba(6, 182, 212, 0.32), rgba(236, 72, 153, 0.32));
  border-color: rgba(34, 211, 238, 0.6);
}

/* Workshop Hero / Intro Panel */
.workshop-hero {
  position: relative;
  background: var(--grad-hero);
  border: 1px solid var(--border-strong);
  border-left: 6px solid var(--accent-magenta);
  border-radius: var(--radius-lg);
  padding: clamp(1.65rem, 3.8vw, 2.75rem);
  margin-bottom: 2.75rem;
  box-shadow: var(--shadow-panel);
  overflow: hidden;
}

.workshop-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 800;
  color: #ffffff;
  background: linear-gradient(90deg, #4f46e5 0%, #db2777 100%);
  padding: 0.3rem 0.85rem;
  border-radius: 999px;
  margin-bottom: 1rem;
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.25);
}

.hero-lead {
  font-size: clamp(1.12rem, 2.1vw, 1.32rem);
  color: var(--text-primary);
  max-width: 68ch;
  margin-bottom: 1rem;
  font-weight: 600;
}

/* Stats / Quick Highlights Bar */
.stats-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(185px, 1fr));
  gap: 0.9rem;
  margin-top: 1.65rem;
  padding-top: 1.35rem;
  border-top: 1px solid var(--border-subtle);
}

.stat-pill {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-left: 4px solid var(--accent-teal);
  border-radius: var(--radius-sm);
  padding: 0.8rem 1rem;
  box-shadow: var(--shadow-card);
}

.stat-pill:nth-child(2) { border-left-color: var(--accent-amber); }
.stat-pill:nth-child(3) { border-left-color: var(--accent-magenta); }
.stat-pill:nth-child(4) { border-left-color: var(--accent-emerald); }

.stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.12rem;
  font-weight: 800;
  color: var(--accent-teal);
}

.stat-pill:nth-child(2) .stat-value { color: var(--accent-amber); }
.stat-pill:nth-child(3) .stat-value { color: var(--accent-magenta); }
.stat-pill:nth-child(4) .stat-value { color: var(--accent-emerald); }

.stat-label {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Buttons */
.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.62rem 1.15rem;
  font-size: 0.92rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.18s ease;
}

.btn-primary {
  background: linear-gradient(135deg, #4f46e5 0%, #db2777 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(219, 39, 119, 0.28);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #4338ca 0%, #be185d 100%);
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(219, 39, 119, 0.4);
}

.btn-cyan {
  background: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(2, 132, 199, 0.28);
}

.btn-cyan:hover {
  background: linear-gradient(135deg, #0369a1 0%, #1d4ed8 100%);
  color: #ffffff;
  transform: translateY(-1px);
}

.btn-emerald {
  background: linear-gradient(135deg, #059669 0%, #0d9488 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(5, 150, 105, 0.28);
}

.btn-emerald:hover {
  background: linear-gradient(135deg, #047857 0%, #0f766e 100%);
  color: #ffffff;
  transform: translateY(-1px);
}

.btn-youtube {
  background: linear-gradient(135deg, #ff0033 0%, #e11d48 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(255, 0, 51, 0.28);
}

.btn-youtube:hover {
  background: linear-gradient(135deg, #d9002b 0%, #be123c 100%);
  color: #ffffff;
  transform: translateY(-1px);
}

.btn-secondary {
  background-color: var(--bg-card);
  color: var(--text-primary);
  border-color: var(--border-strong);
}

.btn-secondary:hover {
  background-color: var(--bg-secondary);
  border-color: var(--accent-teal);
  color: var(--accent-teal);
  transform: translateY(-1px);
}

/* Section Headers & Grid Layouts */
.section-block {
  margin-bottom: 3.25rem;
}

.section-header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
  border-bottom: 2px solid var(--border-subtle);
  padding-bottom: 0.65rem;
  margin-bottom: 1.45rem;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-magenta);
  display: block;
  margin-bottom: 0.25rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.35rem;
}

.card-grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 1.35rem;
}

/* Colorful Engineering Cards */
.card {
  position: relative;
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-top: 5px solid var(--accent-teal);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-card);
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-panel);
}

.card.card-amber { border-top-color: #f97316; }
.card.card-synth { border-top-color: #ec4899; }
.card.card-emerald { border-top-color: #10b981; }
.card.card-coral { border-top-color: #f43f5e; }
.card.card-violet { border-top-color: #6366f1; }

.card-top {
  margin-bottom: 1rem;
}

.card h3 a {
  color: var(--text-primary);
  text-decoration: none;
}

.card h3 a:hover {
  color: var(--accent-magenta);
  text-decoration: underline;
}

.card-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.8rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--text-muted);
}

/* Badges & Colorful Tech Tags */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 800;
  padding: 0.22rem 0.65rem;
  border-radius: 999px;
  border: 1px solid transparent;
}

.badge-progress {
  background-color: var(--accent-amber-soft);
  color: var(--accent-amber);
  border-color: rgba(234, 88, 12, 0.35);
}

.badge-experimental {
  background-color: var(--accent-magenta-soft);
  color: var(--accent-magenta);
  border-color: rgba(219, 39, 119, 0.35);
}

.badge-active {
  background-color: var(--accent-emerald-soft);
  color: var(--accent-emerald);
  border-color: rgba(5, 150, 105, 0.35);
}

.badge-coral {
  background-color: var(--accent-coral-soft);
  color: var(--accent-coral);
  border-color: rgba(225, 29, 72, 0.35);
}

.badge-draft {
  background-color: var(--accent-teal-soft);
  color: var(--accent-teal);
  border-color: rgba(2, 132, 199, 0.35);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  list-style: none;
  padding: 0;
  margin: 0.75rem 0 1rem;
}

.tag-list li {
  margin: 0;
}

.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-secondary);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
}

.tag.tag-c { color: var(--accent-teal); border-color: rgba(2, 132, 199, 0.35); background: var(--accent-teal-soft); }
.tag.tag-esp { color: var(--accent-amber); border-color: rgba(234, 88, 12, 0.35); background: var(--accent-amber-soft); }
.tag.tag-rust { color: var(--accent-coral); border-color: rgba(225, 29, 72, 0.35); background: var(--accent-coral-soft); }
.tag.tag-python { color: var(--accent-violet); border-color: rgba(109, 40, 217, 0.35); background: var(--accent-violet-soft); }
.tag.tag-hw { color: var(--accent-emerald); border-color: rgba(5, 150, 105, 0.35); background: var(--accent-emerald-soft); }
.tag.tag-synth { color: var(--accent-magenta); border-color: rgba(219, 39, 119, 0.35); background: var(--accent-magenta-soft); }

/* Project Card Learning / Next Step Callouts */
.project-notes {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-left: 4px solid var(--accent-violet);
  border-radius: var(--radius-sm);
  padding: 0.9rem 1.05rem;
  margin: 0.85rem 0 1.1rem;
  font-size: 0.92rem;
}

.project-notes p {
  margin-bottom: 0.45rem;
}

.project-notes p:last-child {
  margin-bottom: 0;
}

.card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  padding-top: 0.95rem;
  border-top: 1px solid var(--border-subtle);
}

/* ==========================================================================
   YouTube Proof-of-Concept (PoC) Video Placeholder Component
   ========================================================================== */
.poc-video-section {
  margin: 2rem 0 2.75rem;
}

.poc-video-card {
  position: relative;
  background: var(--bg-card);
  border: 2px solid rgba(225, 29, 72, 0.35);
  border-top: 6px solid #ff0033;
  border-radius: var(--radius-lg);
  padding: clamp(1.35rem, 3vw, 2.2rem);
  box-shadow: var(--shadow-panel);
  overflow: hidden;
}

.poc-video-screen {
  position: relative;
  aspect-ratio: 16 / 9;
  width: 100%;
  background:
    radial-gradient(circle at 50% 50%, rgba(255, 0, 51, 0.22), transparent 60%),
    linear-gradient(135deg, #1e1b4b 0%, #31102f 55%, #0f172a 100%);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 1.5rem;
  color: #f8fafc;
}

.poc-play-badge {
  width: 74px;
  height: 52px;
  background: linear-gradient(135deg, #ff0033 0%, #e11d48 100%);
  border-radius: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 0 8px rgba(255, 0, 51, 0.22), 0 10px 28px rgba(255, 0, 51, 0.5);
  margin-bottom: 1rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.poc-video-screen:hover .poc-play-badge {
  transform: scale(1.07);
  box-shadow: 0 0 0 12px rgba(255, 0, 51, 0.3), 0 14px 32px rgba(255, 0, 51, 0.65);
}

.poc-play-triangle {
  width: 0;
  height: 0;
  border-top: 10px solid transparent;
  border-bottom: 10px solid transparent;
  border-left: 18px solid #ffffff;
  margin-left: 4px;
}

.poc-status-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #ffe4e6;
  background: rgba(244, 63, 94, 0.28);
  border: 1px solid rgba(251, 113, 133, 0.55);
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  margin-bottom: 0.6rem;
}

.poc-video-title {
  font-size: clamp(1.15rem, 2.2vw, 1.45rem);
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 0.4rem;
}

.poc-video-desc {
  color: #e2e8f0;
  max-width: 58ch;
  font-size: 0.94rem;
  margin-bottom: 0;
}

/* Callout / Philosophy Panels */
.callout-box {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-strong);
  border-left: 5px solid var(--accent-teal);
  border-radius: var(--radius-md);
  padding: 1.4rem 1.55rem;
  margin: 1.5rem 0;
}

.callout-box.amber {
  border-left-color: var(--accent-amber);
}

.callout-box.magenta {
  border-left-color: var(--accent-magenta);
}

.callout-title {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-teal);
  margin-bottom: 0.5rem;
  display: block;
}

.callout-box.amber .callout-title {
  color: var(--accent-amber);
}

.callout-box.magenta .callout-title {
  color: var(--accent-magenta);
}

/* Figure & Schematic Frames + Zoomable Images */
.schematic-frame {
  background-color: var(--bg-card);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  padding: 1.1rem;
  margin: 1.6rem 0;
  box-shadow: var(--shadow-card);
}

.schematic-caption {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-top: 0.75rem;
  text-align: center;
}

.zoomable-img {
  cursor: zoom-in;
  transition: transform 0.2s ease;
}

.zoomable-img:hover {
  transform: scale(1.015);
}

/* Lightbox Overlay */
.lightbox-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.92);
  backdrop-filter: blur(8px);
  z-index: 2000;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.lightbox-backdrop[hidden] {
  display: none;
}

.lightbox-Backdrop-img {
  max-width: 92vw;
  max-height: 82vh;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-strong);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.65);
  background: #ffffff;
}

.lightbox-caption {
  margin-top: 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: #f8fafc;
  text-align: center;
}

.lightbox-close {
  position: absolute;
  top: 1.25rem;
  right: 1.5rem;
  background: #ff0033;
  color: #ffffff;
  border: none;
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.95rem;
  font-family: var(--font-mono);
  font-weight: 700;
  cursor: pointer;
}

/* Breadcrumb / Back Navigation */
.breadcrumb {
  margin-bottom: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
}

.breadcrumb a {
  color: var(--accent-teal);
  text-decoration: none;
}

.breadcrumb a:hover {
  color: var(--accent-magenta);
  text-decoration: underline;
}

/* Filter Toolbar for Blog */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.filter-btn {
  background-color: var(--bg-card);
  color: var(--text-secondary);
  border: 1px solid var(--border-strong);
  padding: 0.45rem 0.9rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  cursor: pointer;
}

.filter-btn:hover {
  border-color: var(--accent-teal);
  color: var(--text-primary);
}

.filter-btn[aria-pressed="true"] {
  background: var(--grad-brand);
  color: #ffffff;
  border-color: transparent;
}

/* Spec / Component Table */
.spec-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0 1.5rem;
  font-size: 0.95rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.spec-table th,
.spec-table td {
  text-align: left;
  padding: 0.8rem 1rem;
  border-bottom: 1px solid var(--border-subtle);
}

.spec-table th {
  background-color: var(--bg-secondary);
  color: var(--accent-violet);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.spec-table td {
  color: var(--text-secondary);
}

/* Footer */
.site-footer {
  background-color: var(--bg-secondary);
  border-top: 2px solid var(--border-subtle);
  padding: 2.25rem 0;
  margin-top: auto;
  font-size: 0.92rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.1rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-links li {
  margin: 0;
}

/* Responsive Mobile Navigation */
@media (max-width: 840px) {
  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    width: 100%;
    display: none;
  }

  .site-nav.is-open {
    display: block;
    padding: 0.75rem 0 1rem;
    border-top: 1px solid var(--border-subtle);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0.25rem;
  }

  .nav-link {
    display: block;
    padding: 0.65rem 0.85rem;
  }
}

/* Accessibility: Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}