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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: white;
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

h1 {
    color: #2c3e50;
    margin-bottom: 30px;
    padding-bottom: 10px;
    border-bottom: 3px solid #3498db;
}

h2 {
    color: #34495e;
    margin-top: 30px;
    margin-bottom: 15px;
    font-size: 1.5em;
}

h3 {
    color: #555;
    margin-top: 20px;
    margin-bottom: 10px;
    font-size: 1.4em;
}

.cell {
    margin-bottom: 30px;
    padding: 15px;
    border-radius: 5px;
}

.markdown-cell {
    background-color: transparent;
}

.code-cell {
    background-color: #f8f9fa;
}

.output-cell {
    background-color: #fff;
    margin-top: 10px;
    padding: 15px;
}

pre {
    background-color: #2d2d2d;
    color: #f8f8f2;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 14px;
    line-height: 1.5;
}

code {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 14px;
}

/* Python syntax highlighting styles */
code.python .hl-c { color: #75715e; font-style: italic; } /* Comments */
code.python .hl-s { color: #e6db74; } /* Strings */
code.python .hl-k { color: #66d9ef; } /* Keywords */
code.python .hl-nb { color: #a6e22e; } /* Built-in functions */
code.python .hl-m { color: #ae81ff; } /* Numbers */
code.python .hl-o { color: #f92672; } /* Operators */

.markdown-cell code {
    background-color: #f4f4f4;
    padding: 2px 6px;
    border-radius: 3px;
    color: #c7254e;
}

p {
    margin-bottom: 15px;
}

ul, ol {
    margin-left: 20px;
    margin-bottom: 15px;
}

li {
    margin-bottom: 8px;
}

.output-text {
    white-space: pre-wrap;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 14px;
}

.output-image {
    max-width: 100%;
    height: auto;
    margin: 15px 0;
    border-radius: 5px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 15px 0;
}

th, td {
    border: 1px solid #ddd;
    padding: 12px;
    text-align: left;
}

th {
    background-color: #3498db;
    color: white;
}

tr:nth-child(even) {
    background-color: #f2f2f2;
}

blockquote {
    border-left: 4px solid #3498db;
    margin: 15px 0;
    padding-left: 20px;
    color: #666;
    font-style: italic;
}

a {
    color: #3498db;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.colab-badge {
    margin: 20px 0; 
}

.skill-check {
    background-color: #e8f5e9;
    border-left: 4px solid #4caf50;
    padding: 15px;
    margin: 20px 0;
}

.green-square {
    font-size: 1.5em;
    margin: 10px 0;
}

.info-box {
    background-color: #e3f2fd;
    border-left: 4px solid #2196f3;
    padding: 20px;
    margin: 20px 0;
    border-radius: 5px;
}

.info-box h3 {
    margin-top: 0;
    color: #1976d2;
}

.info-box a {
    color: #1976d2;
    font-weight: bold;
}

.breadcrumb-nav {
    font-size: 0.9em;
    color: #666;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid #e0e0e0;
}

.breadcrumb-nav a {
    color: #3498db;
    text-decoration: none;
}

.breadcrumb-nav a:hover {
    text-decoration: underline;
}

.breadcrumb-nav .separator {
    margin: 0 6px;
    color: #999;
    user-select: none;
}

.chapter-nav {
    display: flex;
    gap: 10px;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid #e0e0e0;
    justify-content: center;
    flex-wrap: wrap;
}

.nav-button {
    display: inline-block;
    padding: 8px 16px;
    background-color: #3498db;
    color: white;
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.9em;
    transition: background-color 0.2s;
    border: none;
    cursor: pointer;
}

.nav-button:hover {
    background-color: #2980b9;
    text-decoration: none;
}

.nav-button.nav-disabled {
    background-color: #bdc3c7;
    color: #7f8c8d;
    cursor: not-allowed;
    pointer-events: none;
}