.container > h1 { 
    color: var(--dark-grey);
    text-align: center;
    border-bottom: 3px solid var(--h1-main-border-color); 
    padding-bottom: 25px;
    margin-top: 0;
    margin-bottom: 40px;
    font-size: 2.4em;
    font-weight: 600;
}

h2 { 
    color: var(--primary-color);
    margin-top: 50px; 
    border-bottom: 2px solid var(--h2-border-color);
    padding-bottom: 15px;
    font-size: 2em;
    font-weight: 600;
}



h3 { 
    color: var(--accent-color);
    margin-top: 35px;
    font-size: 1.6em;
    
}

#overview .chapter-summary h3 { 
    font-size: 1.3em;
    margin-top:0;
    margin-bottom: 10px;
    font-weight: 500;
}
#overview .chapter-summary h3 a {
    text-decoration: none;
    color: var(--accent-color);
}
#overview .chapter-summary h3 a:hover {
    text-decoration: underline;
    color: var(--overview-link-hover-color);
}


.function-block h3 { 
    color: var(--accent-color); 
    margin-top: 0; 
    margin-bottom: 15px;
    font-size: 1.4em; 
    font-weight: 600;
}


h4 { 
    color: var(--h4-color);
    margin-top:25px;
    margin-bottom:12px;
    font-size: 1.2em;
    font-weight: 600;
}

p, .container ul, .container li { 
    margin-bottom: 16px;
    font-size: 1.05em;
}
.container ul { padding-left: 30px; } 
.container li { margin-bottom: 10px; } 


#overview ul {
    list-style-type: none;
    padding-left: 0;
}
#overview .chapter-summary {
    background-color: var(--overview-chapter-bg);
    border: 1px solid var(--overview-chapter-border);
    border-left: 5px solid var(--overview-chapter-border-left);
    padding: 20px;
    margin-bottom: 25px;
    border-radius: 8px;
}
#overview .chapter-summary p {
    font-size: 1em;
    line-height: 1.6;
    margin-bottom: 0; 
}


pre {
    background-color: var(--pre-bg-color);
    padding: 20px;
    border: 1px solid var(--pre-border-color);
    border-left: 5px solid var(--pre-border-left-color);
    border-radius: 8px;
    overflow-x: auto;
    font-size: 1em; 
    line-height: 1.7;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}
code {
    font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;
    font-size: 0.95em; 
    background-color: #f0f0f0; 
    padding: 0.2em 0.4em;
    border-radius: 3px;
}
pre code { 
    font-size: 1em; 
    background-color: transparent;
    padding: 0;
    border-radius: 0;
}


.function-block {
    margin-bottom: 40px;
    padding: 30px;
    border: 1px solid var(--function-block-border);
    border-radius: 10px;
    background-color: var(--function-block-bg);
    box-shadow: 0 3px 7px var(--function-block-shadow);
}
.explanation { margin-bottom: 15px; }
.code-example pre {
    background-color: var(--code-example-pre-bg);
    border-left-color: var(--code-example-pre-border-left);
}
.output-example pre {
    background-color: var(--output-example-pre-bg);
    border-left-color: var(--output-example-pre-border-left);
    color: var(--output-example-text-color);
}


#practice-exercises details {
    border: 1px solid var(--exercise-details-border);
    border-radius: 6px;
    padding: 15px;
    margin-bottom: 20px;
    background-color: var(--exercise-details-bg);
}
#practice-exercises summary {
    font-weight: 600;
    cursor: pointer;
    color: var(--exercise-summary-color);
    font-size: 1.1em;
    padding: 5px;
    transition: color 0.2s ease;
}
#practice-exercises summary:hover { color: var(--exercise-summary-hover-color); }
#practice-exercises .solution pre {
    background-color: var(--exercise-solution-pre-bg);
    border-left: 4px solid var(--exercise-solution-pre-border);
    margin-top: 10px;
}