/* === LAYOUT === */
    .learn-layout {
      display: flex;
      min-height: 100vh;
      padding-top: 6rem;
    }

    .sidebar {
      width: 300px;
      background: var(--gray-800);
      border-right: 1px solid rgba(255,255,255,0.1);
      padding: 2rem;
      position: fixed;
      height: 100%;
      overflow-y: auto;
    }

    .content {
      flex: 1;
      margin-left: 300px;
      padding: 2rem;
      max-width: 900px;
    }

    /* === SIDEBAR === */
    .module-list { list-style: none; }
    .module-item {
      padding: 0.8rem 1rem;
      border-radius: 0.75rem;
      margin-bottom: 0.5rem;
      cursor: pointer;
      transition: all 0.2s;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .module-item:hover, .module-item.active {
      background: rgba(99,102,241,0.2);
      color: white;
    }
    .module-item i { font-size: 0.9rem; }
    .module-item.completed { color: #10b981; }

    /* === ARTICLE – GITHUB MARKDOWN CLONE === */
    .article {
      background: rgba(30,41,59,0.6);
      border-radius: 1.5rem;
      padding: 2rem;
      backdrop-filter: blur(10px);
      max-width: 800px;
      margin: 0 auto;
    }

    .article h1 {
      font-size: 2em;
      margin: 0.67em 0;
      font-weight: 600;
      padding-bottom: 0.3em;
      border-bottom: 1px solid var(--border);
      color: var(--text-heading);
    }

    .article h2 {
      font-size: 1.5em;
      margin: 1.5em 0 0.75em;
      font-weight: 600;
      padding-bottom: 0.3em;
      border-bottom: 1px solid var(--border);
      color: var(--text-heading);
    }

    .article h3 {
      font-size: 1.25em;
      margin: 1.5em 0 0.5em;
      font-weight: 600;
      color: var(--text-heading);
    }

    .article p {
      margin: 0 0 1em;
    }

    .article ul, .article ol {
      margin: 0 0 1em;
      padding-left: 2em;
    }

    .article li {
      margin: 0.25em 0;
    }

    .article li > p { margin: 0; }

    .article blockquote {
      margin: 1em 0;
      padding: 0 1em;
      color: var(--text-muted);
      border-left: 0.25em solid #30363d;
      font-style: italic;
    }

    /* === CODE BLOCKS – NO DOUBLE BACKGROUND === */
    .article pre {
      background: transparent !important;
      padding: 0;
      margin: 1em 0;
      overflow-x: auto;
    }

    .article code {
      font-family: 'JetBrains Mono', ui-monospace, SFMono-Regular, "SF Mono", Consolas, "Liberation Mono", Menlo, monospace;
      font-size: 0.875em;
      background: #30363d;
      padding: 0.2em 0.4em;
      border-radius: 3px;
    }

    /* === PATTERN BLOCKS – CLEAN & GITHUB-STYLE === */
    .pattern {
      background: var(--bg-code);
      padding: 1rem;
      border-radius: 6px;
      margin: 1.5em 0;
      overflow-x: auto;
      font-family: 'JetBrains Mono', monospace;
      font-size: 0.9rem;
      line-height: 1.45;
      color: #c9d1d9;
    }

    .pattern code {
      background: none;
      padding: 0;
      color: inherit;
      font-size: inherit;
    }

    .article img {
      max-width: 100%;
      border-radius: 0.75rem;
      margin: 1rem 0;
    }

    /* === TABLE – GITHUB STYLE === */
    .article table {
      display: table;
      width: 100%;
      border-collapse: separate;
      border-spacing: 0;
      margin: 1.5em 0;
      font-size: 14px;
    }

    .article thead {
      background: var(--bg-table-header);
    }

    .article th {
      padding: 6px 13px;
      border: 1px solid var(--border);
      font-weight: 600;
      text-align: left;
      color: var(--text-heading);
    }

    .article td {
      padding: 6px 13px;
      border: 1px solid var(--border);
      color: var(--text);
    }

    .article tr:nth-child(even) {
      background: #0d1117;
    }

    .article hr {
      height: 1px;
      background: var(--border);
      border: none;
      margin: 2em 0;
    }

    /* === PROGRESS & BUTTONS === */
    .progress-bar {
      height: 6px;
      background: rgba(255,255,255,0.1);
      border-radius: 999px;
      margin: 2rem 0;
      overflow: hidden;
    }

    .progress-fill {
      height: 100%;
      background: var(--gradient);
      width: 0%;
      transition: width 0.6s ease;
    }

    .nav-buttons {
      display: flex;
      justify-content: space-between;
      margin-top: 2rem;
    }

    .nav-btn {
      background: var(--gradient);
      color: white;
      padding: 0.8rem 1.5rem;
      border: none;
      border-radius: 999px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .nav-btn:disabled {
      background: #475569;
      cursor: not-allowed;
    }

    /* === RESPONSIVE === */
    @media (max-width: 992px) {
      .learn-layout { flex-direction: column; }
      .sidebar {
        position: relative;
        width: 100%;
        height: auto;
        padding: 1rem;
        border-right: none;
        border-bottom: 1px solid rgba(255,255,255,0.1);
      }
      .content {
        margin-left: 0;
        padding: 1rem;
      }
      .article {
        padding: 1.5rem;
        border-radius: 1rem;
      }
    }