:root {
      --soil: #1C1408;
      --soil-mid: #261c0a;
      --blue: #38C8FF;
      --blue-dim: rgba(56,200,255,0.11);
      --green: #5ADB8A;
      --green-dim: rgba(90,219,138,0.13);
      --orange: #E07A28;
      --orange-dim: rgba(224,122,40,0.12);
      --canvas: #F0EAE0;
      --card: #FDF9F3;
      --border: #DDD5C4;
      --text-1: #1a1208;
      --text-2: #4a4030;
      --muted: #9a9070;
      --tc: #0d9488;
      --tc-dim: rgba(13,148,136,0.1);
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { font-size: 14px; }
    body { font-family: 'Nunito', sans-serif; background: var(--canvas); color: var(--text-1); min-height: 100vh; line-height: 1.6; }

    /* ── Page shell ── */
    .view { display: none; }
    .view.active { display: block; }

    /* ═══════════════════════════════════════
       LANDING
    ═══════════════════════════════════════ */
    .landing-hero { background: var(--soil); padding: 60px 24px 52px; text-align: center; }
    .landing-eyebrow { font-family: 'Fira Code', monospace; font-size: 11px; color: var(--green); letter-spacing: 2px; text-transform: uppercase; margin-bottom: 16px; }
    .landing-hero h1 { font-family: 'Outfit', sans-serif; font-size: 38px; font-weight: 800; color: #F0EBE0; letter-spacing: -0.6px; margin-bottom: 14px; line-height: 1.15; }
    .landing-hero h1 em { color: var(--orange); font-style: normal; }
    .landing-hero p { color: rgba(240,235,224,0.62); font-size: 15px; max-width: 560px; margin: 0 auto; }

    .track-grid { max-width: 1040px; margin: 0 auto; padding: 44px 24px 64px; }

    .audience-section + .audience-section { margin-top: 52px; }
    .audience-eyebrow {
      font-family: 'Fira Code', monospace;
      font-size: 13px; color: var(--text-2);
      letter-spacing: 1.5px; text-transform: uppercase;
      padding: 10px 24px 10px 20px;
      margin-bottom: 20px;
      border-left: 3px solid var(--green);
      background: var(--green-dim);
    }
    .track-section-grid {
      max-width: 1040px; margin: 0 auto; padding: 0 24px;
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 22px;
    }

    .track-card { background: var(--card); border: 1.5px solid var(--border); border-radius: 10px; padding: 28px 24px 24px; cursor: pointer; transition: transform 0.18s, box-shadow 0.18s, border-color 0.18s; position: relative; overflow: hidden; }
    .track-card::before { content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px; background: var(--tc-card); border-radius: 10px 10px 0 0; }
    .track-card:hover { transform: translateY(-4px); box-shadow: 0 10px 28px rgba(28,20,8,0.13); border-color: var(--tc-card); }
    .track-card:focus-visible { outline: 2px solid var(--tc-card); outline-offset: 2px; }

    .track-number { font-family: 'Fira Code', monospace; font-size: 16px; color: var(--muted); letter-spacing: 1.5px; margin-bottom: 12px; }
    .track-icon { font-size: 38px; margin-bottom: 14px; display: block; }
    .track-card h2 { font-family: 'Outfit', sans-serif; font-size: 26px; font-weight: 700; color: var(--text-1); letter-spacing: -0.2px; margin-bottom: 10px; }
    .track-card > p { font-size: 16px; color: var(--text-2); line-height: 1.6; margin-bottom: 18px; }

    .track-pills { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 20px; }
    .track-pill { padding: 5px 14px; border-radius: 20px; font-size: 18px; font-weight: 700; }

    .start-btn { display: flex; align-items: center; justify-content: center; gap: 6px; width: 100%; padding: 14px 0; background: var(--tc-card); color: white; border: none; border-radius: 7px; font-family: 'Nunito', sans-serif; font-size: 18px; font-weight: 700; cursor: pointer; transition: opacity 0.15s, transform 0.12s; }
    .start-btn:hover { opacity: 0.87; transform: translateY(-1px); }

    /* ═══════════════════════════════════════
       COURSE HEADER
    ═══════════════════════════════════════ */
    .course-header { background: var(--soil); padding: 18px 24px 0; }

    .breadcrumb { display: flex; align-items: center; gap: 8px; margin-bottom: 14px; }
    .breadcrumb-back { display: flex; align-items: center; gap: 5px; background: none; border: none; color: rgba(240,235,224,0.5); font-family: 'Nunito', sans-serif; font-size: 14px; font-weight: 600; cursor: pointer; padding: 0; transition: color 0.15s; }
    .breadcrumb-back:hover { color: rgba(240,235,224,0.85); }
    .breadcrumb-sep { color: rgba(240,235,224,0.2); font-size: 14px; }
    .breadcrumb-current { font-family: 'Outfit', sans-serif; font-size: 14px; font-weight: 600; color: rgba(240,235,224,0.72); }

    .course-header-title { font-family: 'Outfit', sans-serif; font-size: 17px; font-weight: 700; color: #F0EBE0; margin-bottom: 22px; }

    /* ── Signal path progress ── */
    .progress-rail { display: flex; align-items: flex-start; overflow-x: auto; scrollbar-width: none; padding-bottom: 20px; }
    .progress-rail::-webkit-scrollbar { display: none; }

    .p-node { display: flex; flex-direction: column; align-items: center; flex-shrink: 0; width: 84px; cursor: pointer; }
    .p-node-dot { width: 28px; height: 28px; border-radius: 50%; border: 2px solid rgba(255,255,255,0.14); background: rgba(255,255,255,0.06); display: flex; align-items: center; justify-content: center; font-family: 'Fira Code', monospace; font-size: 12px; color: rgba(255,255,255,0.38); transition: all 0.22s; position: relative; z-index: 1; }
    .p-node.done .p-node-dot { background: var(--tc); border-color: var(--tc); color: white; }
    .p-node.active .p-node-dot { background: var(--tc); border-color: var(--tc); color: white; width: 34px; height: 34px; animation: node-pulse 2.4s ease-in-out infinite; }
    @keyframes node-pulse { 0%,100% { box-shadow: 0 0 0 0 var(--tc-pulse,rgba(13,148,136,0.3)); } 50% { box-shadow: 0 0 0 7px transparent; } }
    .p-node-label { font-size: 11px; color: rgba(255,255,255,0.28); margin-top: 6px; text-align: center; max-width: 80px; line-height: 1.3; }
    .p-node.active .p-node-label { color: rgba(255,255,255,0.78); }
    .p-node.done .p-node-label { color: rgba(255,255,255,0.45); }
    .p-node:focus-visible { outline: 2px solid var(--blue); outline-offset: 2px; border-radius: 4px; }

    .p-line { flex: 1; min-width: 14px; height: 2px; background: rgba(255,255,255,0.1); align-self: flex-start; margin-top: 14px; transition: background 0.2s; }
    .p-line.done { background: var(--tc); }

    /* ═══════════════════════════════════════
       COURSE LAYOUT
    ═══════════════════════════════════════ */
    .course-layout { display: grid; grid-template-columns: 232px 1fr; min-height: calc(100vh - 198px); }

    /* ── Sidebar ── */
    .module-sidebar { background: var(--card); border-right: 1.5px solid var(--border); padding: 18px 0; }
    .sb-track-label { font-family: 'Fira Code', monospace; font-size: 12px; color: var(--muted); letter-spacing: 1.5px; text-transform: uppercase; padding: 0 16px 12px; border-bottom: 1px solid var(--border); margin-bottom: 6px; }

    .module-item { display: flex; align-items: flex-start; gap: 10px; padding: 9px 16px; cursor: pointer; border-left: 3px solid transparent; transition: background 0.12s; }
    .module-item:hover { background: rgba(28,20,8,0.04); }
    .module-item.active { background: var(--tc-dim); border-left-color: var(--tc); }

    .m-dot { width: 18px; height: 18px; border-radius: 50%; border: 1.5px solid var(--border); flex-shrink: 0; margin-top: 2px; display: flex; align-items: center; justify-content: center; font-size: 11px; color: white; transition: all 0.15s; }
    .module-item.active .m-dot { background: var(--tc); border-color: var(--tc); }
    .module-item.done .m-dot { background: var(--tc); border-color: var(--tc); }

    .m-text { min-width: 0; }
    .m-num { font-family: 'Fira Code', monospace; font-size: 12px; color: var(--muted); }
    .m-title { font-size: 15px; font-weight: 600; color: var(--text-1); line-height: 1.35; }
    .module-item.active .m-title { color: var(--tc); }
    .module-item.done .m-title { color: var(--text-2); }
    .m-dur { font-size: 12px; color: var(--muted); margin-top: 2px; }

    /* ── Lesson pane ── */
    .lesson-pane { padding: 36px 52px 48px; max-width: 740px; }

    .lesson-eyebrow { font-family: 'Fira Code', monospace; font-size: 12px; color: var(--muted); letter-spacing: 1.5px; text-transform: uppercase; margin-bottom: 8px; }
    .lesson-title { font-family: 'Outfit', sans-serif; font-size: 30px; font-weight: 800; color: var(--text-1); letter-spacing: -0.4px; margin-bottom: 6px; line-height: 1.2; }
    .lesson-meta { font-size: 14px; color: var(--muted); margin-bottom: 30px; display: flex; align-items: center; gap: 12px; }
    .lesson-meta span { display: flex; align-items: center; gap: 4px; }

    /* lesson body elements */
    .lesson-body h3 { font-family: 'Outfit', sans-serif; font-size: 20px; font-weight: 700; color: var(--text-1); margin: 28px 0 10px; letter-spacing: -0.2px; }
    .lesson-body p { font-size: 17px; color: var(--text-2); line-height: 1.72; margin-bottom: 14px; }
    .lesson-body ul { padding-left: 20px; margin-bottom: 16px; }
    .lesson-body ul li { font-size: 17px; color: var(--text-2); line-height: 1.66; margin-bottom: 7px; }
    .lesson-body strong { color: var(--text-1); font-weight: 700; }
    .lesson-body code { font-family: 'Fira Code', monospace; font-size: 14px; background: rgba(28,20,8,0.07); padding: 1px 5px; border-radius: 3px; }

    .callout { border-radius: 8px; padding: 13px 18px; margin: 20px 0; font-size: 16px; line-height: 1.65; }
    .callout-blue  { background: var(--blue-dim);   border-left: 3px solid var(--blue); }
    .callout-green { background: var(--green-dim);  border-left: 3px solid var(--green); }
    .callout-orange{ background: var(--orange-dim); border-left: 3px solid var(--orange); }

    .code-block { background: var(--soil); color: #5ADB8A; font-family: 'Fira Code', monospace; font-size: 14px; padding: 16px 20px; border-radius: 8px; margin: 16px 0; overflow-x: auto; line-height: 1.75; white-space: pre; }
    .code-block .cm { color: rgba(90,219,138,0.45); }
    .code-block .kw { color: #38C8FF; }
    .code-block .st { color: #E07A28; }

    .key-takeaway { background: var(--card); border: 1.5px solid var(--border); border-radius: 8px; padding: 15px 20px; margin-top: 30px; }
    .key-takeaway-label { font-family: 'Fira Code', monospace; font-size: 12px; color: var(--muted); letter-spacing: 1.5px; text-transform: uppercase; margin-bottom: 7px; }
    .key-takeaway p { font-size: 16px; color: var(--text-1); font-weight: 600; margin: 0; line-height: 1.55; }

    /* ── Lesson nav ── */
    .lesson-nav { display: flex; align-items: center; justify-content: space-between; margin-top: 40px; padding-top: 22px; border-top: 1.5px solid var(--border); }
    .lesson-nav-btn { display: inline-flex; align-items: center; gap: 8px; padding: 10px 20px; border-radius: 7px; font-family: 'Nunito', sans-serif; font-size: 15px; font-weight: 700; cursor: pointer; border: 1.5px solid var(--border); background: var(--card); color: var(--text-1); transition: border-color 0.15s, color 0.15s, transform 0.1s; }
    .lesson-nav-btn:hover:not(:disabled) { border-color: var(--tc); color: var(--tc); }
    .lesson-nav-btn:disabled { opacity: 0.32; cursor: not-allowed; }
    .lesson-nav-btn.primary { background: var(--tc); border-color: var(--tc); color: white; }
    .lesson-nav-btn.primary:hover:not(:disabled) { opacity: 0.88; color: white; }

    /* ── Completion screen ── */
    .completion-view { text-align: center; padding: 64px 24px; max-width: 540px; margin: 0 auto; }
    .completion-icon { font-size: 52px; margin-bottom: 20px; }
    .completion-view h2 { font-family: 'Outfit', sans-serif; font-size: 30px; font-weight: 800; letter-spacing: -0.4px; color: var(--text-1); margin-bottom: 12px; }
    .completion-view p { font-size: 16px; color: var(--text-2); margin-bottom: 28px; line-height: 1.65; }
    .completion-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
    .btn-outline { padding: 10px 22px; border: 1.5px solid var(--border); border-radius: 7px; background: var(--card); color: var(--text-1); font-family: 'Nunito', sans-serif; font-size: 15px; font-weight: 700; cursor: pointer; text-decoration: none; display: inline-flex; align-items: center; gap: 6px; transition: border-color 0.15s, color 0.15s; }
    .btn-outline:hover { border-color: var(--tc); color: var(--tc); }
    .btn-solid { padding: 10px 22px; border-radius: 7px; background: var(--tc); color: white; border: none; text-decoration: none; font-family: 'Nunito', sans-serif; font-size: 15px; font-weight: 700; cursor: pointer; display: inline-flex; align-items: center; gap: 6px; transition: opacity 0.15s; }
    .btn-solid:hover { opacity: 0.87; }

    /* ── Mobile module nav ── */
    .mobile-module-nav { display: none; padding: 10px 16px; background: var(--card); border-bottom: 1.5px solid var(--border); }
    .mobile-module-nav select { width: 100%; padding: 8px 12px; border-radius: 6px; border: 1.5px solid var(--border); background: var(--card); color: var(--text-1); font-family: 'Nunito', sans-serif; font-size: 15px; font-weight: 600; cursor: pointer; appearance: none; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%239a9070' d='M6 8L1 3h10z'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 12px center; padding-right: 32px; }

    @media (max-width: 960px) {
      .track-section-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 720px) {
      .course-layout { grid-template-columns: 1fr; }
      .module-sidebar { display: none; }
      .mobile-module-nav { display: block; }
      .lesson-pane { padding: 24px 20px 36px; }
      .lesson-title { font-size: 21px; }
      .landing-hero h1 { font-size: 26px; }
      .track-grid { padding: 32px 16px 48px; }
      .track-section-grid { grid-template-columns: 1fr; }
    }
  
.lesson-done{color:#16a34a;font-weight:700}
.completion-note{font-size:12px;color:var(--muted)}

/* -- Further Reading -- */
.further-reading { margin-top: 32px; padding-top: 24px; border-top: 1.5px solid var(--border); text-align: left; max-width: 420px; margin-left: auto; margin-right: auto; }
.further-reading-label { font-family: 'Fira Code', monospace; font-size: 12px; color: var(--muted); letter-spacing: 1.5px; text-transform: uppercase; margin-bottom: 12px; }
.further-reading-list { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.further-reading-link { font-size: 15px; font-weight: 600; color: var(--tc); text-decoration: none; display: inline-flex; align-items: center; gap: 6px; transition: opacity 0.15s; }
.further-reading-link:hover { opacity: 0.75; text-decoration: underline; }