/* ==========================================================================
   1. GLOBAL UI & TYPOGRAPHY
   - This section defines the core look and feel of the site, including
     fonts, background colors, default text styles, and link behavior.
   ========================================================================== */

/* Imports the 'Architects Daughter', 'Roboto', and 'Share Tech Mono' fonts from Google Fonts. */
@import url('https://fonts.googleapis.com/css2?family=Architects+Daughter&family=Roboto:wght@300;400;500;700&family=Share+Tech+Mono&display=swap');

/* Defines a local font 'Dejavu Sans Mono' for code blocks. */
@font-face {
    font-family: "Dejavu Sans Mono";
    src: url("DejaVuSansMono.ttf") format("truetype");
}

/* Base styles for the entire page. */
body {
    background-color: #1b201d;  /* Dark slate background for a consistent, professional theme. */
    color: #e2dfd1 !important;  /* A soft, off-white for readability on the dark background. */
    font-family: 'Roboto', sans-serif; /* Sets the default font for all text. */
    margin: 0; /* Removes default browser margin. */
}

/* Provides consistent padding for the main content area. */
main {
    padding-left: 10px !important;  /* Creates space from the left edge or sidebar. */
    padding-right: 10px !important; /* Creates space from the right edge. */
    padding-top: 5px; /* Adds a little space at the top. */
}

/* Utility class for larger, highlighted text sections. */
.lead {
    font-family: 'Roboto', sans-serif;
    border-left: 3px solid #8f00b3;
    padding-left: 20px;
    font-style: italic;
}

/* Enables smooth scrolling when navigating to an anchor link (e.g., #section). */
html {
    scroll-behavior: smooth;
}

/* repair the scrill bounce and layout shifting on mobile when using anchor links */
html, body {
    /* Prevents the 'pull-to-refresh' bounce and layout shifting */
    overscroll-behavior-y: none; 
    /* Ensures the body takes up exactly the viewport height without shifting */
    height: 100%;
    overflow-x: hidden;
}

/*
 * OFFSETS FOR STICKY HEADER
 * These rules prevent content from being hidden behind the sticky header when jumping to an anchor link.
 * The `scroll-margin-top` property adds space above the element when it's scrolled to.
 */
[id], h1, h2, h3, h4, h5, section, .card-slate {
    scroll-margin-top: 100px !important; /* Value should be roughly the height of the sticky header. */
}

/*
 * STICKY HEADER
 * This section styles the main header container that stays at the top of the viewport during scroll.
 */
#dynamic-header {
    position: sticky;     /* Makes the header stay at the top. */
    top: 0;               /* Pins it to the very top of the viewport. */
    z-index: 1020;        /* Ensures it stays above most page content. */
    background-color: black; /* Matches the main container background. */
    padding-left: 0 !important;
    padding-right: 0 !important;
    padding-top: 2px;
    min-height: 85px; /* Reserves a minimum height for the header area. */
}

/* Resets spacing for rows inside the sticky header to prevent unwanted gaps. */
#dynamic-header .row {
    margin: 0 !important;
    padding: 0 !important;
    --bs-gutter-y: 0px !important; /* Removes vertical gutter spacing for Bootstrap rows. */
    margin-left: 0 !important;
    margin-right: 0 !important;
}

/* Hard reset for column padding within the header to ensure alignment. */
#dynamic-header .col,
#dynamic-header .col-auto {
    padding-left: 0 !important;
}

/* Defines a max-width for the main content container and centers it. */
.container {
    background-color: black;
    max-width: 1020px;
    margin: 0 auto; /* Centers the container horizontally. */
}

/* Remove the forced padding on fluid containers used for full-width elements. */
.container-fluid {
    padding-left: 5px !important;
    padding-right: 5px !important;
}

/* Utility class to center text. */
.center {
    text-align: center;
}

/* Overrides Bootstrap's default secondary text and alert colors to match the site's theme. */
.text-secondary, .alert-secondary {
    color: #e2dfd1 !important;
    font-family: 'Roboto', sans-serif;
}

/*
 * TYPOGRAPHY
 * Defines styles for headings, paragraphs, and links.
 */

/* Base styles for all heading levels. */
h1, h2, h3, h4, h5 {
    font-family: 'Roboto', sans-serif;
    padding-top: 0.1rem;
    padding-bottom: 0.1rem;
}

/* Specific styles for each heading level. */
h1 { color: #8f00b3; font-size: 2.0rem; padding-top: 0.3rem; } /* Main page title - purple */
h2 { color: #cc6600; font-size: 1.8rem; padding-top: 0.2rem; } /* Section title - orange */
h3 { color: #2cba77; font-size: 1.4rem; font-weight: 600; }   /* Sub-section title - green */
h4 { color: rgb(39, 168, 149); font-size: 1.2rem; font-weight: 600; } /* Card/item title - teal */
h5 { color: rgb(232, 157, 251); font-size: 1.1rem; font-weight: 600; } /* Minor heading - light purple */

/* Default font size for common text elements. */
p, div, tr, th, td {
    font-size: 1rem;
}

/* Link styling. */
a {
    text-decoration: none; /* Removes the default underline. */
    transition: color 0.3s; /* Smooth color transition on hover. */
    color: rgb(77, 210, 247); /* Default link color - cyan. */
}
a:hover {
    color: hotpink; /* Changes color on hover. */
    text-decoration: underline; /* Adds underline on hover for clarity. */
}
a:active {
    color: purple; /* Color when a link is being clicked. */
}

/* Styles images with rounded corners. */
img {
    border-radius: 5px;
}

/* ==========================================================================
   2. HERO & BLACKBOARD
   - This section styles the large "blackboard" banner at the top of some pages.
   ========================================================================== */

.hero-blackboard {
    width: 100%;
    height: 320px; /* Fixed height to ensure consistent layout. */
    background: url('https://sagecode.org/images/blackboard.jpg') no-repeat center center;
    background-size: cover; /* Ensures the background image covers the whole area. */
    display: flex;
    justify-content: flex-start;
    align-items: flex-start;
    padding: 10px; /* Provides inner spacing. */
    box-shadow: inset 0 0 100px rgba(0,0,0,0.9); /* Creates a vignette effect. */
    overflow: hidden; /* Prevents content from spilling out. */
    margin-bottom: 2rem; /* Adds space below the hero. */
}

/* "Chalk" style text for headings on the blackboard. */
.chalk-text {
    font-family: 'Architects Daughter', cursive;
    color: rgba(227, 98, 98, 0.95); /* Off-white for a realistic chalk look. */
    font-size: 2rem;
    margin-top: 0;
    margin-bottom: 15px;
    padding-top: 0 !important;
    text-shadow: 1px 1px 2px rgba(255,255,255,0.3), 0 0 10px rgba(255,255,255,0.1); /* Glow effect. */
    transform: rotate(-0.5deg); /* Slight rotation for a hand-written feel. */
}

/* "Chalk" style for body text on the blackboard. */
.chalk-body {
    font-family: 'Architects Daughter', cursive;
    color: rgba(230, 230, 230, 0.85);
    font-size: 1.4rem;
    white-space: normal;
    line-height: 1.4;
    margin-top: 0;
    max-width: 860px;
    text-shadow: 1px 1px 1px rgba(255,255,255,0.2);
    letter-spacing: 0.5px;
}

/* Area for the typewriter effect in the hero section. */
.typewriter-area {
    flex-grow: 1; /* Takes up all available middle space. */
    margin-top: 10px;
    min-height: 300px;
}

.manifesto-wrapper {
    margin-top: auto; /* Pushes the link to the bottom of the hero area. */
    padding-bottom: 10px;
}

/* Responsive adjustments for the blackboard on smaller screens. */
@media screen and (max-width: 768px) {
    .hero-blackboard {
        padding-top: 10px;
        padding-left: 5px;
        padding-right: 5px;
    }

    .chalk-text {
        font-size: 1.4rem;
        line-height: 1.2;
        padding-top: 0px;
        padding-bottom: 0.1rem;
        margin-bottom: 0px;
    }

    .chalk-body {
        font-size: 1.2rem;
        line-height: 1.2;
        word-break: break-word; /* Prevents text overflow. */
        padding-top: 0;
        padding-left: 0;
        padding-right: 0;
        hyphens: auto; /* Allows for better word breaking on small screens. */
    }
}

/* ==========================================================================
   3. SYNTAX HIGHLIGHTING & CODE
   - Styles for code blocks and inline code, creating a custom theme.
   ========================================================================== */

/* Styles the <pre> tag, which contains code blocks. */
pre {
    border-radius: 5px;
    padding: 10px;
    color: lightgreen; /* Default text color for code. */
    background-color: #241f31; /* Dark purple/blue background. */
}

/* Sets the font and base styles for code. */
code[class*="language-"], pre[class*="language-"] {
    color: darkseagreen;
    font-family: "Dejavu Sans Mono", "Share Tech Mono", monospace;
    line-height: 1.2rem;
    font-size: 0.95rem;
}

/*
 * SYNTAX TOKENS
 * Defines colors for different parts of the code (keywords, strings, comments, etc.).
 */
.keyword { color: orange; }
.keytab { color: gold; }
.impera, .directive-hash { color: palevioletred; }
.control { color: deepskyblue; }
.interrupt, .operator { color: lightcoral; }
.type, .constant, .builtin { color: cyan; }
.title { color: springgreen; }
.subtitle { color: silver; }
.comment { color: lightseagreen; }
.string { color: yellow; }

/* ==========================================================================
   4. CARDS, PANELS, AND TABLES
   - Layout and styling for structured content containers.
   ========================================================================== */

/* Utility class for a generic panel heading. */
.panel-heading {
    background-color: #19334d; /* Dark blue background. */
    color: silver;
    padding: 10px;
    margin-top: 10px !important;
    border-radius: 5px 5px 0px 0px; /* Rounded top corners. */
}

/* A panel used specifically for displaying code. */
.code-panel {
    height: 100%;
    color: lightgreen;
    border-radius: 0px 0px 5px 5px; /* Rounded bottom corners. */
}

/* Table header cells. */
th {
    color: #e60073; /* Pink text color. */
    background-color: #19334d !important; /* Dark blue background. */
    font-weight: 500;
    font-size: 1.2rem;
    padding: 10px;
}

/* Styling for header rows within tables, used to group related items. */
.table-group-header th {
    background-color: #242424 !important; /* Constant solid black. */
    color: #8f00b3 !important;            /* Sage-Code Purple. */
    font-size: 0.85rem;
    letter-spacing: 1.5px; /* Wider spacing for a "header" feel. */
    border-top: 2px solid #333 !important;
    border-bottom: 1px solid #333 !important;
    padding-top: 15px !important;
    padding-bottom: 10px !important;
}

/*
 * CARD STYLES
 * A "slate" is a custom card component.
 */
.card-slate {
    background-color: #1a1a1a; /* Very dark gray, almost black. */
    border: 1px solid #333; /* Subtle border. */
    border-radius: 5px;
    transition: 0.3s;
    height: 100%; /* Ensures cards in a row have the same height. */
    display: flex;
    flex-direction: column;
    margin: 0;
    box-sizing: border-box;
}

/* Standard padding for the body of a card. */
.card-body {
    padding: 1rem !important;
}

/* Card titles, overriding Bootstrap defaults. */
.card-title {
    font-family: Roboto, Tahoma, Verdana, Sans-Serif;
    color: rgb(117, 204, 241) !important; /* Light blue color. */
    font-size: 1.2rem;
    margin-top: 0;
    margin-bottom: 10px;
}

/* Justified text alignment for card content. */
.card-text-justified {
    font-size: 0.95rem;
    color: #e2dfd1;
    text-align: justify;
    margin: 0;
}

/*
 * ROW CHECK HIGHLIGHTING
 * Styles for table rows that contain a checkbox, indicating a "completed" state.
 */

/* Removes any background color when a checkbox in a row is checked. */
tr:has(input:checked) {
    background-color: transparent !important;
}

/* Instead of a background, the text color is changed to indicate a checked state. */
tr:has(input:checked) td {
    color: #d0cfd0ec !important; /* Muted text color. */
    opacity: 0.9;                /* Slightly dims the row. */
}

/* Adds a glow effect when hovering over a checked row. */
tr:has(input:checked):hover td {
    color: hotpink !important;  /* Bright hover color for feedback. */
    opacity: 1;
    text-shadow: 0 0 8px rgba(255, 105, 180, 0.4); /* Subtle pink glow. */
}

/* ==========================================================================
   5. INTERACTIVE ELEMENTS
   - Buttons, links, and other interactive components.
   ========================================================================== */

/* Overrides Bootstrap's primary button style. */
.btn-primary {
    background-color: #0d6efd;
    border: 1px solid #0d6efd;
    color: white;
    padding: 10px 20px;
    transition: 0.2s ease-in-out;
}

.btn-primary:hover {
    background-color: rgba(247, 0, 255, 0.6); /* Purple/pink on hover. */
    border-color: white;
}

/* A custom class for YouTube links to make them look like buttons. */
.youtube {
    color: white;
    background: red;
    border-radius: 6px;
    padding: 5px 10px;
    font-family: "Share Tech Mono", monospace;
}

/* Horizontal rule color. */
hr {
    color: rgb(136, 46, 204); /* Sage Purple */
}

/* Special text color utility. */
.highlight-discord {
    color: #fc7f18; /* Sage Orange */
    font-weight: bold;
}

/* ==========================================================================
   6. HEADER & NAVIGATION
   - Styles for the site header, main navigation, and breadcrumbs.
   ========================================================================== */

.site-header {
    background: transparent;
    padding-top: 15px;
    padding-bottom: 10px;
    padding-left: 0px;
}

/* Main navigation link container. */
.nav-links {
    display: flex; /* Aligns nav items in a row. */
    gap: 25px; /* Space between nav items. */
    list-style: none; /* Removes bullet points. */
    margin: 0;
    padding: 0; /* Critical for right-alignment. */
}

/* Individual navigation links. */
.nav-links a {
    font-family: 'Share Tech Mono', monospace;
    color: #888; /* Muted color for unselected links. */
    text-transform: uppercase;
    font-size: 0.9rem;
    transition: 0.3s;
}

.nav-links a:hover {
    color: #fc7f18; /* Sage Orange on hover. */
}

/* Breadcrumb navigation bar (e.g., Home > Engineering > Concepts). */
.breadcrumb-nav {
    font-family: 'Share Tech Mono', monospace;
    font-size: 0.75rem;
    text-transform: uppercase;
    color: #444; /* Very subtle text color. */
    padding-top: 2px;
    padding-bottom: 2px;
    margin-left: 0 !important;
    padding-left: 0 !important;
    border-top: 1px solid rgb(136, 46, 204);
    border-bottom: 1px solid rgb(136, 46, 204);
}

.breadcrumb-nav a { color: #666; }
.breadcrumb-nav .sep { color: #333; } /* Separator character (e.g., '>'). */
.breadcrumb-nav .current { color: #fc7f18; } /* Color for the current page. */
.breadcrumb-nav i {
    margin-right: 5px;
    vertical-align: middle;
}
.breadcrumb-nav a,
.breadcrumb-nav span {
    display: inline-block;
    vertical-align: middle;
}

/* Hamburger menu for mobile. Initially hidden on larger screens. */
.hamburger {
    display: none;
}

/* Mobile navigation styles. */
@media (max-width: 640px) {
    /* Hides the desktop nav links and shows the hamburger icon. */
    .nav-links {
        display: none;
        position: absolute;
        top: 60px;
        right: 20px;
        background: #0a0a0a;
        border: 1px solid #333;
        flex-direction: column;
        width: 180px;
        padding: 10px;
        z-index: 100;
    }
    /* When active, the mobile nav menu is shown. */
    .nav-links.active {
        display: flex;
    }
    .hamburger {
        display: flex;
        flex-direction: column;
        gap: 5px;
        cursor: pointer;
    }
    /* The three lines of the hamburger icon. */
    .hamburger span {
        width: 22px;
        height: 2px;
        background: #fc7f18;
    }
}

.progress {
    height: 20px;
    background-color: #333; /* Dark background for the progress bar. */
    border-radius: 3px;
}

/* ==========================================================================
   7. SIDEBAR & BOOKMARKS
   - Styles for the left sidebar, including the collapsible study checklist.
   ========================================================================== */

/* The main container for the sidebar on desktop. */
.side-bar {
    border-right: 2px solid rgba(216, 26, 216, 0.2); /* Very subtle purple edge. */
    margin-left: 0px !important;
    padding-left: 0px !important;
}

/* The content area within the sidebar that becomes scrollable. */
.sidebar-content {
    background-color: rgba(0, 0, 0, 0.2); /* Darker than body for depth. */
    padding-right: 10px !important;
    padding-left: 0px !important;
    margin-left: 0px !important;
}

/* Custom Scrollbar for the sidebar (WebKit browsers like Chrome/Safari). */
.sidebar-content::-webkit-scrollbar { width: 4px; }
.sidebar-content::-webkit-scrollbar-track { background: transparent; }
.sidebar-content::-webkit-scrollbar-thumb { background: #333; border-radius: 3px; }
.sidebar-content::-webkit-scrollbar-thumb:hover { background: #8f00b3; } /* Purple hover on scrollbar. */


/* --- DESKTOP: STICKY SIDEBAR --- */
@media (min-width: 992px) {
    .sidebar-content {
        position: sticky; /* Makes sidebar stick during scroll. */
        top: 85px;      /* Sits below the 85px header with a 10px gap. */
        z-index: 1010;  /* Below the header (1020). */
        max-height: calc(100vh - 100px); /* Max height is the viewport height minus header. */
        overflow-y: auto; /* Enables scrolling only when content overflows. */
        display: block;
        margin-left: 5px !important;
        padding-left: 5px !important;
    }
}

/* --- MOBILE: SLIDE-OUT OVERLAY --- */
@media (max-width: 991px) {
    /* Styles the sidebar container, positioned off-screen to the left. */
    #study-sidebar {
        position: fixed;
        top: 0;
        left: -100%; /* Initially hidden off-screen. */
        width: 280px;
        height: 100vh;
        z-index: 2000;
        background-color: #1a1a1a !important;
        transition: left 0.3s ease; /* Smooth slide-in animation. */
        overflow-y: auto;
        padding: 20px 25px !important;
        display: block !important;
    }

    /* When active, the sidebar slides into view. */
    #study-sidebar.active {
        left: 0;
        box-shadow: 10px 0 30px rgba(0,0,0,0.8); /* Adds depth. */
    }

    #study-sidebar .sidebar-content {
        background-color: #1a1a1a !important;
        padding-left: 15px !important;
        margin-left: 0 !important;
    }
    
    /* Ensure sub-items indent properly on mobile */
    #study-sidebar #bookmark-list ul {
        padding-left: 15px !important; 
        margin-left: 14px !important;
        border-left: 1px solid #756e6e;
    }

    #study-sidebar #bookmark-list {
        padding-left: 5px !important;
    }

    /* Adds padding to the bottom of the main content to prevent it from being hidden by the mobile sidebar toggle button. */
    main, .content-area {
        padding-bottom: 80px !important;
    }
    
    /* The button to open the mobile sidebar. */
    #open-sidebar {
        position: fixed; /* Stays in place during scroll. */
        bottom: 20px;
        right: auto;
        left: 10px;
        width: 60px;
        height: 60px;
        padding: 0;
        display: flex;
        align-items: center;
        justify-content: center;
        border-radius: 50% !important; /* Makes it a circle. */
        z-index: 3500;
    }
}


/* --- BOOKMARK LIST (CHECKLIST) --- */

/* Base styles for the list container. */
#bookmark-list {
    list-style: none; /* Removes default bullets. */
    padding-left: 0;
    font-family: 'Roboto', sans-serif;
    font-size: 0.85rem;
    color: #b0af9e;
}

/* Styles for each list item. */
#bookmark-list li {
    display: block;
    margin-bottom: 8px;
    line-height: 1.2;
}

/* Nested lists (sub-topics) are indented and have a guide line. */
#bookmark-list ul {
    list-style: none;
    padding-left: 15px; /* Creates space between the line and the text. */
    margin-top: 5px;
    margin-bottom: 10px;
    margin-left: 22px;  /* Positions the line away from the parent checkbox. */
    border-left: 1px solid #444; /* Vertical guide line for the "tree" view. */
}

/* Default link state in the bookmark list. */
#bookmark-list a {
    text-decoration: none;
    color: #e2dfd1;
    transition: color 0.3s, opacity 0.3s;
    margin-left: 5px; /* Space between checkbox and link text. */
}

/* Hover state for links. */
#bookmark-list a:hover {
    color: hotpink !important;
    text-decoration: none;
}

/*
 * CHECKED STATE STYLING
 * Uses the :has() pseudo-class to style the link when its sibling checkbox is checked.
 */
#bookmark-list li:has(input:checked) a {
    color: #87b9d49d; /* Muted blue color. */
    font-weight: 500;
    opacity: 0.8;   /* Dims the text to indicate completion. */
}

/* Hovering over a link that is already checked. */
#bookmark-list li:has(input:checked) a:hover {
    color: hotpink !important; /* Still pops with the bright hover color. */
    opacity: 1;
    text-decoration: underline;
}


/* --- CUSTOM CHECKBOX --- */

/* Hides the default browser checkbox. */
.topic-check,
.form-check-input {
    appearance: none;
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    border: 1px solid #555;
    border-radius: 3px;
    background-color: #111;
    cursor: pointer;
    position: relative;
    top: 2px;
    flex-shrink: 0;
}

/* Styles the checkbox when it is checked. */
.topic-check:checked,
.form-check-input:checked {
    background-color: #2cba77 !important; /* Sage Green */
    border-color: #2cba77 !important;
}

/* Creates the "check" mark using a pseudo-element. */
.topic-check:checked::after {
    content: '✔';
    font-size: 9px;
    color: #000;
    position: absolute;
    top: 0px;
    left: 2px;
}

/* ==========================================================================
   8. MISCELLANEOUS & UTILITIES
   - Various helper classes and styles for specific components.
   ========================================================================== */

/* Inverts the color of social media icons, useful for dark mode. */
.fix-social {
    filter: invert(1);
    position: relative;
}

/* A grid layout for step-by-step guides or feature lists. */
.card-grid-steps {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    row-gap: 5px;
    column-gap: 10px;
    padding: 5px 0;
    width: 100%;
}

/* Styles for individual cards within the step grid. */
.step-card {
    align-items: flex-start !important;
    text-align: left !important;
    padding: 10px !important;
}

/* Large number for the step indicator. */
.step-number {
    font-family: 'Share Tech Mono', monospace;
    font-size: 2.5rem;
    color: rgb(136, 46, 204); /* Sage Purple */
    line-height: 1;
    margin-bottom: 10px;
}

/* Layout for metadata at the top of a card (e.g., star rating, badges). */
.card-meta-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

/* Star rating display. */
.star-rating {
    font-size: 0.7rem;
    cursor: help;
    white-space: nowrap;
}
.stars-on { color: #fd7e14; } /* Orange for filled stars. */
.stars-off { color: #444; }  /* Gray for empty stars. */

/* Hint badges with a help cursor. */
.badge-hint {
    cursor: help;
    font-size: 0.7rem;
    padding: 0.4em 0.7em;
}

/*
 * BOOK & RESOURCE STYLES
 * Cards specifically for displaying book recommendations.
 */
.book-card {
    background-color: #1a1a1a;
    border: 1px solid #333;
    border-radius: 5px;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 10px;
    transition: transform 0.3s ease;
}

.book-card:hover {
    transform: translateY(-5px); /* Lifts the card on hover. */
    border-color: rgb(136, 46, 204); /* Adds a purple glow on hover. */
}

.book-card img {
    max-width: 200px; /* Constrains book cover size. */
    margin-bottom: 10px;
    border-radius: 2px; /* Book covers shouldn't have rounded corners. */
    box-shadow: 0 4px 10px rgba(0,0,0,0.5); /* Adds depth to the book cover. */
}

.book-card button {
    margin-top: 10px;
}

/* Styling for a resource link, often associated with a book. */
.book-resource {
    background: #111;
    border: 1px solid #333;
    border-left: 4px solid rgb(136, 46, 204); /* Purple accent line. */
    padding: 15px;
    display: flex;
    align-items: center;
    gap: 15px;
}


/* ==========================================================================
   9. RESPONSIVE VIDEO & FOOTER
   ========================================================================== */
.responsive-video-container {
    max-width: 50vw;
    margin: 0 auto;
    position: relative;
    padding-bottom: 28%; /* Aspect ratio hack. */
    height: 0;
    overflow: hidden;
    border-radius: 5px;
}

.responsive-video-container video {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    object-fit: contain;
}

/* Adjusts video container for mobile. */
@media screen and (max-width: 768px) {
    .responsive-video-container {
        max-width: 90vw;
        padding-bottom: 56%;
    }
    #main-img {
        width: 100%;
    }
}

@media screen and (min-width: 640px) {
    .top-video { position: absolute; top: 0; left: 15%; width: 70%; height: 100%; }
    .frame-host { padding: 50% 0 0 0; position: relative; }
    #main-img { width: 70%; }
}

/* Footer styling. */
.footer {
    position: relative;
    padding-top: 20px;
    padding-bottom: 20px;
    background-color: black;
    color: rgba(255, 255, 255, 0.784);
    width: 100%;
    border-top: 1px solid #800568;
}

.footer.copyright p {
    text-align: center;
    margin-left: auto;
    margin-right: auto;
}