/* SDCourse sales page */
.theme-sdcourse {

    /* ════════════════════════════════════════════════════════
       DESIGN SYSTEM
       Tone: editorial / engineering journal
       Dark base, warm paper accents, code-terminal details
       ════════════════════════════════════════════════════════ */
    :root {
      --ink:        #0e0f13;
      --ink-2:      #1a1c23;
      --ink-3:      #252830;
      --border:     #2e313d;
      --border-2:   #3a3e4d;
      --muted:      #7a7f91;
      --body:       #c8cad4;
      --head:       #eceef4;
      --paper:      #f5f0e8;
      --amber:      #e8a23c;
      --amber-dim:  #a06820;
      --green:      #3ecf8e;
      --green-dim:  #1a6b48;
      --red:        #e85c5c;
      --blue:       #5b8dee;

      --font-serif: 'DM Serif Display', Georgia, serif;
      --font-sans:  'DM Sans', system-ui, sans-serif;
      --font-mono:  'DM Mono', 'Fira Code', monospace;

      --max-w: 1080px;
      --radius: 8px;
    }

    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

    html { scroll-behavior: smooth; }

    body {
      background: var(--ink);
      color: var(--body);
      font-family: var(--font-sans);
      font-size: 16px;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }

    /* ── Utilities ─────────────────────────────────────────── */
    .container { max-width: var(--max-w); margin: 0 auto; padding: 0 1.5rem; }
    .sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); }

    a { color: var(--amber); text-decoration: none; }
    a:hover { text-decoration: underline; }

    strong { color: var(--head); font-weight: 600; }

    code, .mono {
      font-family: var(--font-mono);
      font-size: 0.875em;
      background: var(--ink-3);
      border: 1px solid var(--border);
      padding: 0.1em 0.45em;
      border-radius: 4px;
      color: var(--amber);
    }

    /* ── Scroll-reveal ─────────────────────────────────────── */
    .reveal { opacity: 0; transform: translateY(28px); transition: opacity 0.6s ease, transform 0.6s ease; }
    .reveal.visible { opacity: 1; transform: translateY(0); }

    /* ════════════════════════════════════════════════════════
       NAV
       ════════════════════════════════════════════════════════ */
    nav {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(14,15,19,0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border);
      padding: 0.9rem 0;
    }
    nav .inner {
      max-width: var(--max-w);
      margin: 0 auto;
      padding: 0 1.5rem;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 1rem;
    }
    .nav-logo {
      font-family: var(--font-mono);
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--head);
      letter-spacing: 0.04em;
    }
    .nav-logo span { color: var(--amber); }
    nav ul { list-style: none; display: flex; gap: 1.75rem; }
    nav ul a { font-size: 0.85rem; color: var(--muted); font-weight: 500; transition: color 0.2s; }
    nav ul a:hover { color: var(--head); text-decoration: none; }
    .nav-cta {
      background: var(--amber);
      color: var(--ink) !important;
      font-weight: 600;
      font-size: 0.82rem;
      padding: 0.5rem 1.1rem;
      border-radius: 5px;
      transition: opacity 0.2s !important;
    }
    .nav-cta:hover { opacity: 0.85; text-decoration: none !important; }

    /* ════════════════════════════════════════════════════════
       HERO
       ════════════════════════════════════════════════════════ */
    .hero {
      padding: 7rem 0 5rem;
      position: relative;
      overflow: hidden;
    }
    /* Subtle grid texture */
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background-image:
        linear-gradient(var(--border) 1px, transparent 1px),
        linear-gradient(90deg, var(--border) 1px, transparent 1px);
      background-size: 48px 48px;
      opacity: 0.2;
      pointer-events: none;
    }
    /* Radial glow */
    .hero::after {
      content: '';
      position: absolute;
      top: -20%;
      left: 50%;
      transform: translateX(-50%);
      width: 900px;
      height: 600px;
      background: radial-gradient(ellipse at center, rgba(232,162,60,0.08) 0%, transparent 70%);
      pointer-events: none;
    }
    .hero .container { position: relative; z-index: 1; }

    .hero-eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      font-family: var(--font-mono);
      font-size: 0.72rem;
      font-weight: 500;
      letter-spacing: 0.12em;
      text-transform: uppercase;
      color: var(--amber);
      border: 1px solid var(--amber-dim);
      padding: 0.3em 0.8em;
      border-radius: 3px;
      margin-bottom: 1.75rem;
    }
    .hero-eyebrow::before {
      content: '';
      display: inline-block;
      width: 6px; height: 6px;
      background: var(--amber);
      border-radius: 50%;
      animation: pulse 2s ease-in-out infinite;
    }
    @keyframes pulse {
      0%, 100% { opacity: 1; transform: scale(1); }
      50%       { opacity: 0.4; transform: scale(0.8); }
    }

    .hero h1 {
      font-family: var(--font-serif);
      font-size: clamp(2.6rem, 6vw, 4.8rem);
      line-height: 1.1;
      color: var(--head);
      letter-spacing: -0.02em;
      max-width: 820px;
      margin-bottom: 1.5rem;
    }
    .hero h1 em {
      font-style: italic;
      color: var(--amber);
    }

    .hero-sub {
      font-size: clamp(1rem, 2vw, 1.2rem);
      color: var(--muted);
      max-width: 580px;
      margin-bottom: 2.5rem;
      line-height: 1.65;
    }

    .hero-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 0.75rem;
      align-items: center;
      margin-bottom: 3.5rem;
    }

    .btn-primary {
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      background: var(--amber);
      color: var(--ink);
      font-weight: 700;
      font-size: 0.95rem;
      padding: 0.8rem 1.8rem;
      border-radius: 6px;
      transition: opacity 0.2s, transform 0.2s;
    }
    .btn-primary:hover { opacity: 0.88; transform: translateY(-1px); text-decoration: none; }

    .btn-ghost {
      display: inline-flex;
      align-items: center;
      gap: 0.4rem;
      color: var(--muted);
      font-size: 0.9rem;
      font-weight: 500;
      border: 1px solid var(--border-2);
      padding: 0.8rem 1.4rem;
      border-radius: 6px;
      transition: border-color 0.2s, color 0.2s;
    }
    .btn-ghost:hover { border-color: var(--amber); color: var(--amber); text-decoration: none; }

    /* Stats bar */
    .stats-bar {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
      gap: 0;
      border: 1px solid var(--border);
      border-radius: var(--radius);
      overflow: hidden;
      background: var(--ink-2);
    }
    .stat {
      padding: 1.25rem 1.5rem;
      border-right: 1px solid var(--border);
    }
    .stat:last-child { border-right: none; }
    .stat-num {
      font-family: var(--font-serif);
      font-size: 2.2rem;
      color: var(--head);
      line-height: 1;
      margin-bottom: 0.25rem;
    }
    .stat-num span { color: var(--amber); }
    .stat-label { font-size: 0.78rem; color: var(--muted); line-height: 1.4; }

    /* ════════════════════════════════════════════════════════
       SECTION HEADERS
       ════════════════════════════════════════════════════════ */
    .section { padding: 5.5rem 0; }
    .section-label {
      font-family: var(--font-mono);
      font-size: 0.7rem;
      letter-spacing: 0.14em;
      text-transform: uppercase;
      color: var(--amber);
      margin-bottom: 0.75rem;
    }
    .section-title {
      font-family: var(--font-serif);
      font-size: clamp(1.9rem, 4vw, 3rem);
      color: var(--head);
      line-height: 1.15;
      letter-spacing: -0.02em;
      margin-bottom: 1rem;
    }
    .section-sub {
      font-size: 1.05rem;
      color: var(--muted);
      max-width: 560px;
      line-height: 1.65;
    }

    /* ════════════════════════════════════════════════════════
       PROBLEM / HOOK SECTION
       ════════════════════════════════════════════════════════ */
    .problem {
      background: var(--ink-2);
      border-top: 1px solid var(--border);
      border-bottom: 1px solid var(--border);
      padding: 5rem 0;
    }
    .problem-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2.5rem 4rem;
      align-items: start;
      margin-top: 3rem;
    }
    .problem-item {
      display: flex;
      gap: 1rem;
      align-items: flex-start;
    }
    .problem-icon {
      flex-shrink: 0;
      width: 36px;
      height: 36px;
      border-radius: 6px;
      background: rgba(232,162,60,0.1);
      border: 1px solid var(--amber-dim);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1rem;
      margin-top: 0.1rem;
    }
    .problem-text strong {
      display: block;
      font-size: 0.95rem;
      margin-bottom: 0.25rem;
    }
    .problem-text p { font-size: 0.88rem; color: var(--muted); line-height: 1.55; }

    /* ════════════════════════════════════════════════════════
       WHAT YOU BUILD — SYSTEM DIAGRAM
       ════════════════════════════════════════════════════════ */
    .system-diagram {
      background: var(--ink-2);
      border: 1px solid var(--border);
      border-radius: 12px;
      padding: 2rem;
      margin: 3rem 0;
      overflow-x: auto;
    }
    .diagram-label {
      font-family: var(--font-mono);
      font-size: 0.65rem;
      letter-spacing: 0.12em;
      text-transform: uppercase;
      color: var(--muted);
      margin-bottom: 1.5rem;
    }
    .diagram-flow {
      display: flex;
      align-items: center;
      gap: 0;
      flex-wrap: nowrap;
      min-width: 700px;
    }
    .diagram-node {
      background: var(--ink-3);
      border: 1px solid var(--border-2);
      border-radius: 6px;
      padding: 0.75rem 1rem;
      text-align: center;
      flex-shrink: 0;
    }
    .diagram-node .node-name {
      font-family: var(--font-mono);
      font-size: 0.72rem;
      color: var(--head);
      font-weight: 500;
    }
    .diagram-node .node-tech {
      font-size: 0.62rem;
      color: var(--muted);
      margin-top: 0.2rem;
    }
    .diagram-arrow {
      flex: 1;
      min-width: 24px;
      height: 1px;
      background: var(--border-2);
      position: relative;
    }
    .diagram-arrow::after {
      content: '›';
      position: absolute;
      right: -6px;
      top: 50%;
      transform: translateY(-50%);
      color: var(--muted);
      font-size: 0.85rem;
    }

    /* Module modules grid */
    .modules-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
      gap: 1px;
      background: var(--border);
      border: 1px solid var(--border);
      border-radius: 10px;
      overflow: hidden;
      margin-top: 2.5rem;
    }
    .module-card {
      background: var(--ink-2);
      padding: 1.5rem 1.75rem;
      position: relative;
      transition: background 0.2s;
    }
    .module-card:hover { background: var(--ink-3); }
    .module-num {
      font-family: var(--font-mono);
      font-size: 0.65rem;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--amber);
      margin-bottom: 0.5rem;
    }
    .module-title {
      font-weight: 600;
      color: var(--head);
      font-size: 1rem;
      margin-bottom: 0.4rem;
    }
    .module-desc { font-size: 0.83rem; color: var(--muted); line-height: 1.5; margin-bottom: 0.75rem; }
    .module-meta {
      font-family: var(--font-mono);
      font-size: 0.68rem;
      color: var(--muted);
      border-top: 1px solid var(--border);
      padding-top: 0.65rem;
      margin-top: 0.5rem;
    }

    /* ════════════════════════════════════════════════════════
       WHO IT'S FOR
       ════════════════════════════════════════════════════════ */
    .for-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1.5rem;
      margin-top: 2.5rem;
    }
    .for-card {
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 1.5rem;
      background: var(--ink-2);
    }
    .for-card h3 {
      font-size: 0.72rem;
      font-family: var(--font-mono);
      letter-spacing: 0.1em;
      text-transform: uppercase;
      margin-bottom: 1rem;
    }
    .for-card.yes h3 { color: var(--green); }
    .for-card.no  h3 { color: var(--red); }
    .for-card ul { list-style: none; display: flex; flex-direction: column; gap: 0.6rem; }
    .for-card ul li {
      display: flex;
      gap: 0.6rem;
      font-size: 0.88rem;
      line-height: 1.45;
    }
    .for-card ul li::before { flex-shrink: 0; margin-top: 0.05em; }
    .for-card.yes ul li::before { content: '✓'; color: var(--green); font-weight: 700; }
    .for-card.no  ul li::before { content: '✗'; color: var(--red); }

    /* ════════════════════════════════════════════════════════
       TESTIMONIALS
       ════════════════════════════════════════════════════════ */
    .testimonials-bg {
      background: var(--ink-2);
      border-top: 1px solid var(--border);
      border-bottom: 1px solid var(--border);
    }
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
      gap: 1.25rem;
      margin-top: 3rem;
    }
    .testimonial {
      background: var(--ink-3);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 1.5rem;
      position: relative;
    }
    .testimonial::before {
      content: '"';
      font-family: var(--font-serif);
      font-size: 3.5rem;
      color: var(--amber);
      opacity: 0.2;
      position: absolute;
      top: 0.25rem;
      left: 1rem;
      line-height: 1;
    }
    .testimonial-text {
      font-size: 0.9rem;
      line-height: 1.6;
      color: var(--body);
      margin-bottom: 1.25rem;
      padding-top: 0.5rem;
    }
    .testimonial-author {
      display: flex;
      align-items: center;
      gap: 0.75rem;
    }
    .author-avatar {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--amber-dim), var(--amber));
      display: flex;
      align-items: center;
      justify-content: center;
      font-family: var(--font-serif);
      font-size: 1rem;
      color: var(--ink);
      font-weight: 700;
      flex-shrink: 0;
    }
    .author-name { font-size: 0.85rem; font-weight: 600; color: var(--head); }
    .author-role { font-size: 0.75rem; color: var(--muted); }

    /* ════════════════════════════════════════════════════════
       PRICING
       ════════════════════════════════════════════════════════ */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.25rem;
      margin-top: 3rem;
    }
    .price-card {
      border: 1px solid var(--border);
      border-radius: 12px;
      padding: 1.75rem;
      background: var(--ink-2);
      display: flex;
      flex-direction: column;
      gap: 0;
      position: relative;
      transition: border-color 0.2s;
    }
    .price-card:hover { border-color: var(--border-2); }
    .price-card.featured {
      border-color: var(--amber);
      background: linear-gradient(160deg, rgba(232,162,60,0.06), var(--ink-2));
    }
    .price-card.featured::before {
      content: 'MOST POPULAR';
      position: absolute;
      top: -1px;
      left: 50%;
      transform: translateX(-50%);
      background: var(--amber);
      color: var(--ink);
      font-family: var(--font-mono);
      font-size: 0.6rem;
      font-weight: 700;
      letter-spacing: 0.1em;
      padding: 0.25em 0.9em;
      border-radius: 0 0 5px 5px;
    }
    .price-tier {
      font-family: var(--font-mono);
      font-size: 0.65rem;
      letter-spacing: 0.12em;
      text-transform: uppercase;
      color: var(--muted);
      margin-bottom: 0.75rem;
    }
    .price-amount {
      font-family: var(--font-serif);
      font-size: 3rem;
      color: var(--head);
      line-height: 1;
      margin-bottom: 0.25rem;
    }
    .price-amount sup {
      font-size: 1.25rem;
      vertical-align: super;
      font-family: var(--font-sans);
      font-weight: 400;
    }
    .price-period {
      font-size: 0.8rem;
      color: var(--muted);
      margin-bottom: 1.5rem;
    }
    .price-features {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 0.6rem;
      margin-bottom: 1.75rem;
      flex: 1;
    }
    .price-features li {
      display: flex;
      gap: 0.6rem;
      font-size: 0.86rem;
      line-height: 1.4;
    }
    .price-features li .chk {
      flex-shrink: 0;
      color: var(--green);
      font-weight: 700;
      margin-top: 0.05em;
    }
    .price-features li .chk.no { color: var(--border-2); }
    .price-cta {
      display: block;
      text-align: center;
      padding: 0.75rem 1rem;
      border-radius: 6px;
      font-weight: 600;
      font-size: 0.9rem;
      transition: opacity 0.2s, transform 0.2s;
    }
    .price-cta:hover { opacity: 0.85; transform: translateY(-1px); text-decoration: none; }
    .price-cta.primary { background: var(--amber); color: var(--ink); }
    .price-cta.outline { border: 1px solid var(--border-2); color: var(--muted); }
    .price-cta.outline:hover { border-color: var(--amber); color: var(--amber); }

    /* ════════════════════════════════════════════════════════
       FAQ
       ════════════════════════════════════════════════════════ */
    .faq-bg {
      background: var(--ink-2);
      border-top: 1px solid var(--border);
    }
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
      margin-top: 3rem;
    }
    .faq-item { }
    .faq-q {
      font-weight: 600;
      color: var(--head);
      font-size: 0.95rem;
      margin-bottom: 0.5rem;
    }
    .faq-a { font-size: 0.88rem; color: var(--muted); line-height: 1.6; }

    /* ════════════════════════════════════════════════════════
       FINAL CTA
       ════════════════════════════════════════════════════════ */
    .final-cta {
      padding: 7rem 0;
      text-align: center;
      position: relative;
      overflow: hidden;
    }
    .final-cta::before {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 800px;
      height: 400px;
      background: radial-gradient(ellipse at bottom, rgba(232,162,60,0.1) 0%, transparent 70%);
      pointer-events: none;
    }
    .final-cta h2 {
      font-family: var(--font-serif);
      font-size: clamp(2rem, 5vw, 3.6rem);
      color: var(--head);
      line-height: 1.15;
      margin-bottom: 1.25rem;
      letter-spacing: -0.02em;
    }
    .final-cta p { color: var(--muted); font-size: 1.05rem; margin-bottom: 2.5rem; }

    /* ════════════════════════════════════════════════════════
       FOOTER
       ════════════════════════════════════════════════════════ */
    footer {
      border-top: 1px solid var(--border);
      padding: 2rem 0;
    }
    .footer-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 1rem;
    }
    .footer-brand {
      font-family: var(--font-mono);
      font-size: 0.85rem;
      color: var(--muted);
    }
    .footer-brand span { color: var(--amber); }
    .footer-links { display: flex; gap: 1.5rem; }
    .footer-links a { font-size: 0.82rem; color: var(--muted); transition: color 0.2s; }
    .footer-links a:hover { color: var(--head); text-decoration: none; }

    /* ════════════════════════════════════════════════════════
       RESPONSIVE
       ════════════════════════════════════════════════════════ */
    @media (max-width: 768px) {
      .problem-grid { grid-template-columns: 1fr; gap: 1.5rem; }
      .for-grid { grid-template-columns: 1fr; }
      .pricing-grid { grid-template-columns: 1fr; }
      .faq-grid { grid-template-columns: 1fr; }
      nav ul { display: none; }
      .stats-bar { grid-template-columns: 1fr 1fr; }
      .stat { border-right: none; border-bottom: 1px solid var(--border); }
      .stat:nth-child(2n) { border-bottom: 1px solid var(--border); }
      .stat:last-child { border-bottom: none; }
    }
  
}
.theme-sdcourse body, body.theme-sdcourse { background: var(--ink); }