/* --- Global Styles & Variables --- */
:root {
    --primary-font: 'Source Sans 3', sans-serif;
    --serif-font: 'Lora', serif;
    --text-color: #333;
    --bg-color: #fdfdfd;
    --accent-color: #007acc;
    --border-color: #ddd;
    --code-bg: #f5f5f5;
    --max-width: 800px;
    --toc-width: 240px;
}

body {
    font-family: var(--serif-font);
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--bg-color);
    margin: 0;
    padding: 0;
    font-size: 18px;
}

/* --- Layout --- */
body {
    display: flex;
    justify-content: center;
}

main {
    max-width: var(--max-width);
    padding: 2rem 1.5rem;
    width: 100%;
}

#toc-container {
    width: var(--toc-width);
    padding: 2rem 1rem;
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
    border-right: 1px solid var(--border-color);
}

/* --- Typography --- */
h1, h2, h3, h4 {
    font-family: var(--primary-font);
    font-weight: 600;
    line-height: 1.3;
    margin-top: 2em;
    margin-bottom: 0.8em;
}

h1 {
    font-size: 2.8rem;
    text-align: center;
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 0.5em;
    margin-bottom: 1em;
}

h2 {
    font-size: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.3em;
}

h3 {
    font-size: 1.5rem;
}

p, ul, ol {
    margin-bottom: 1.2rem;
}

a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: #0056b3;
}

strong {
    font-weight: 600;
}

/* --- Table of Contents --- */
#toc-container h3 {
    margin-top: 0;
    font-size: 1.2rem;
    color: var(--accent-color);
}

#toc {
    display: flex;
    flex-direction: column;
}

#toc a {
    color: #555;
    font-family: var(--primary-font);
    padding: 0.4em 0;
    font-size: 0.9rem;
    border-left: 2px solid transparent;
    padding-left: 1em;
}

#toc a:hover {
    background-color: #f0f0f0;
    border-left-color: var(--accent-color);
}

#toc a.h3 {
    padding-left: 2em;
    font-size: 0.85rem;
}


/* --- Code & Math --- */
pre {
    background: var(--code-bg);
    padding: 1.5em;
    border-radius: 8px;
    overflow-x: auto;
    border: 1px solid var(--border-color);
}

code {
    font-family: 'SF Mono', 'Fira Code', 'Menlo', monospace;
    font-size: 0.9rem;
}

p > code, li > code {
    background-color: var(--code-bg);
    padding: 0.2em 0.4em;
    border-radius: 4px;
}

.katex-display {
    overflow-x: auto;
    overflow-y: hidden;
    padding: 0.5em 0;
}

/* --- Tables --- */
.table-container {
    overflow-x: auto;
    margin: 2em 0;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-family: var(--primary-font);
    font-size: 0.95rem;
}

th, td {
    padding: 0.8em 1em;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: #f9f9f9;
    font-weight: 600;
}

tbody tr:nth-child(even) {
    background-color: #f9f9f9;
}

tbody tr:hover {
    background-color: #f0f8ff;
}

.large-table {
    max-height: 500px;
    overflow-y: auto;
}

/* --- Misc Elements --- */
.mermaid {
    text-align: center;
    margin: 2em 0;
}

.caption {
    text-align: center;
    font-style: italic;
    color: #666;
    margin-top: -1em;
}

.chart-container {
    margin: 3em 0;
    padding: 1.5em;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

/* --- Responsive Design --- */
@media (max-width: 1200px) {
    body {
        flex-direction: column;
    }
    #toc-container {
        position: static;
        width: 100%;
        height: auto;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding: 1rem;
    }
    #toc {
        flex-direction: row;
        flex-wrap: wrap;
    }
    #toc a {
        padding: 0.5em 1em;
    }
    #toc a.h3 {
        padding-left: 2em;
    }
}

@media (max-width: 768px) {
    body {
        font-size: 16px;
    }
    main {
        padding: 1rem;
    }
    h1 {
        font-size: 2.2rem;
    }
    h2 {
        font-size: 1.8rem;
    }
}

/* --- Print Styles --- */
@media print {
  body {
    background: #fff !important;
    color: #222 !important;
    font-size: 14pt !important;
    display: block !important;
    margin: 0;
    padding: 0;
  }
  #toc-container, aside, nav, .chartjs-size-monitor, script, .hljs-ln-numbers {
    display: none !important;
    visibility: hidden !important;
    height: 0 !important;
    width: 0 !important;
    overflow: hidden !important;
  }
  main {
    max-width: none !important;
    width: 100% !important;
    padding: 0 !important;
    margin: 0 !important;
  }
  a {
    color: #555 !important;
    text-decoration: underline dotted #888 !important;
    pointer-events: none !important;
  }
  table, pre, code, .katex-display {
    page-break-inside: avoid !important;
    break-inside: avoid !important;
    background: #f5f5f5 !important;
    color: #222 !important;
    border: 1px solid #bbb !important;
  }
  .table-container, .chart-container {
    page-break-inside: avoid !important;
    break-inside: avoid !important;
    background: none !important;
    border: 1px solid #bbb !important;
    margin-bottom: 1em !important;
    padding: 0.7em !important;
  }
  h1 {
    color: #222 !important;
    background: none !important;
    border-color: #bbb !important;
    page-break-before: always !important;
    page-break-after: avoid !important;
    margin-top: 1em !important;
    margin-bottom: 0.7em !important;
  }
  h2 {
    color: #222 !important;
    background: none !important;
    border-color: #bbb !important;
    page-break-before: auto !important;
    page-break-after: avoid !important;
    margin-top: 1em !important;
    margin-bottom: 0.5em !important;
  }
  h3, h4 {
    color: #222 !important;
    background: none !important;
    border-color: #bbb !important;
    page-break-after: avoid !important;
    margin-top: 0.7em !important;
    margin-bottom: 0.4em !important;
  }
  .caption {
    color: #666 !important;
    margin-top: 0.2em !important;
    margin-bottom: 0.7em !important;
  }
  pre, code {
    background: #f5f5f5 !important;
    color: #222 !important;
    border: 1px solid #bbb !important;
  }
  img, table, .mermaid img, .chart-container img {
    page-break-inside: avoid !important;
    break-inside: avoid !important;
    display: block !important;
    max-width: 100% !important;
    margin: 0.7em auto !important;
  }
  section {
    page-break-after: avoid !important;
    margin-bottom: 1em !important;
    padding-bottom: 0 !important;
    border-bottom: none !important;
  }
  p, ul, ol {
    margin-bottom: 0.7em !important;
  }
  #author-info {
    color: #888 !important;
    font-size: 0.95em !important;
    font-style: italic !important;
    margin-bottom: 0.7em !important;
  }
}