/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Palette inspired by victoriametrics.com: deep purple, orange accent,
   near-black ink. The layout and components are this site's own. */
:root {
    --purple: #621773;
    --purple-600: #7a2590;
    --purple-dim: #f6f1f7;
    --purple-line: #e4d4e8;
    --orange: #e94600;
    --orange-600: #c73c00;
    --orange-dim: #fdf0ea;
    --ink: #08091c;
    --ink-soft: #17181f;
    --text-dark: #23242e;
    --text-light: #5d5e6b;
    --page-bg: #f5f7fa;
    --surface: #ffffff;
    --border-color: #e6e6e9;
    --code-bg: #17181f;
    --radius: 16px;
    --radius-sm: 8px;
    --shadow: 0 10px 26px 1px rgba(112, 112, 112, 0.10);
    --shadow-hover: 0 16px 36px 2px rgba(98, 23, 115, 0.18);
    --brand-gradient: linear-gradient(90deg, var(--purple) 0%, var(--orange) 100%);

    /* Kept for anything still referring to the old names */
    --primary-color: var(--purple);
    --secondary-color: var(--purple-600);
    --accent-color: var(--orange);
    --dark-bg: var(--ink);
    --light-bg: var(--page-bg);
}

body {
    font-family: 'Lato', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Arial, sans-serif;
    font-size: 17px;
    line-height: 1.65;
    color: var(--text-dark);
    background-color: var(--page-bg);
    -webkit-font-smoothing: antialiased;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    margin-top: 1.6em;
    margin-bottom: 0.7em;
    font-weight: 900;
    line-height: 1.25;
    color: var(--ink);
    letter-spacing: -0.01em;
}

h1 {
    font-size: 2.6rem;
    margin-top: 0;
}

h2 {
    font-size: 1.9rem;
    position: relative;
    padding-left: 1rem;
}

h2::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.2em;
    bottom: 0.2em;
    width: 4px;
    border-radius: 4px;
    background: var(--brand-gradient);
    background: linear-gradient(180deg, var(--purple) 0%, var(--orange) 100%);
}

h3 {
    font-size: 1.4rem;
    font-weight: 700;
}

h4 {
    font-weight: 700;
}

p {
    margin-bottom: 1em;
}

a {
    color: var(--purple);
    text-decoration: none;
    text-underline-offset: 3px;
    transition: color 0.2s;
}

a:hover {
    color: var(--orange);
    text-decoration: underline;
}

::selection {
    background: rgba(233, 70, 0, 0.22);
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navbar */
.navbar {
    background-color: var(--ink);
    padding: 0.9rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 18px rgba(8, 9, 28, 0.25);
}

.navbar::after {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    height: 3px;
    background: var(--brand-gradient);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-home {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 1.15rem;
    font-weight: 900;
    color: white !important;
    text-decoration: none !important;
}

.nav-home::before {
    content: '';
    width: 0.7rem;
    height: 0.7rem;
    border-radius: 50%;
    background: var(--orange);
    box-shadow: 0 0 0 4px rgba(233, 70, 0, 0.25);
    flex-shrink: 0;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-links a {
    color: rgba(255, 255, 255, 0.85) !important;
    text-decoration: none !important;
    font-weight: 700;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: white !important;
}

/* Switchers (track and language) */
.lang-switch,
.track-switch {
    border-left: 1px solid rgba(255, 255, 255, 0.2);
    padding-left: 1.5rem;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: rgba(255, 255, 255, 0.85);
    cursor: pointer;
}

.lang-switch select,
.track-switch select {
    appearance: auto;
    background: rgba(255, 255, 255, 0.08);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.25);
    border-radius: 999px;
    padding: 0.3rem 0.8rem;
    font: inherit;
    font-size: 0.9rem;
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
}

.lang-switch select:hover,
.lang-switch select:focus,
.track-switch select:hover,
.track-switch select:focus {
    background: rgba(255, 255, 255, 0.14);
    border-color: var(--orange);
    outline: none;
}

.lang-switch select option,
.track-switch select option {
    color: #111;
    background: #fff;
}

/* Hero Section */
.hero {
    position: relative;
    overflow: hidden;
    text-align: left;
    padding: 4rem 3rem;
    background:
        radial-gradient(circle at 92% 12%, rgba(233, 70, 0, 0.45) 0%, rgba(233, 70, 0, 0) 38%),
        linear-gradient(120deg, var(--ink-soft) 0%, #2a0f35 45%, var(--purple) 100%);
    color: white;
    border-radius: var(--radius);
    margin: 2.5rem 0 2rem;
    box-shadow: var(--shadow);
}

/* A faint grid, like the axes of a chart, behind the hero text */
.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
    background-size: 48px 48px;
    pointer-events: none;
}

.hero > * {
    position: relative;
}

.hero h1 {
    color: white;
    font-size: 3rem;
    max-width: 22ch;
    margin-bottom: 1rem;
}

.hero .lead {
    font-size: 1.25rem;
    max-width: 60ch;
    margin-bottom: 1.5rem;
    color: rgba(255, 255, 255, 0.88);
}

.hero .hero-note {
    background-color: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.18);
    padding: 0.9rem 1.2rem;
    border-radius: 12px;
    display: inline-block;
    margin: 0;
    backdrop-filter: blur(6px);
}

.hero a,
.hero strong {
    color: white;
}

/* Sections */
section {
    background: var(--surface);
    padding: 2.25rem;
    margin: 2rem 0;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

section h2:first-child {
    margin-top: 0;
}

/* Module Grid */
.modules-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.25rem;
    margin-top: 2rem;
}

.module-card-link {
    text-decoration: none !important;
    color: inherit;
    display: block;
}

.module-card-link:hover {
    text-decoration: none !important;
}

.module-card {
    position: relative;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 1.5rem;
    transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s, background 0.25s;
    background: var(--surface);
    height: 100%;
    overflow: hidden;
}

.module-card::after {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    height: 3px;
    background: var(--brand-gradient);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s;
}

.module-card-link:hover .module-card {
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
    border-color: var(--purple-line);
    background: var(--purple-dim);
}

.module-card-link:hover .module-card::after {
    transform: scaleX(1);
}

.module-number {
    display: inline-block;
    background-color: var(--purple-dim);
    color: var(--purple);
    border: 1px solid var(--purple-line);
    padding: 0.2rem 0.8rem;
    border-radius: 999px;
    font-family: 'Ubuntu Mono', ui-monospace, monospace;
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    text-transform: uppercase;
    margin-bottom: 0.75rem;
}

.module-card-link:hover .module-number {
    background-color: var(--purple);
    border-color: var(--purple);
    color: white;
}

.module-card h3 {
    margin: 0.5rem 0;
    font-size: 1.2rem;
    color: var(--ink);
}

.module-card-link:hover .module-card h3 {
    color: var(--purple);
}

.module-card p {
    margin: 0.5rem 0 0 0;
    color: var(--text-light);
    font-size: 0.95rem;
}

/* Code Blocks */
pre {
    background: var(--code-bg) !important;
    border: 1px solid #2a2b36;
    border-radius: 12px;
    padding: 1.5rem;
    padding-top: 1.9rem;
    overflow-x: auto;
    margin: 1.5rem 0;
    line-height: 1.55;
    box-shadow: 0 10px 24px rgba(8, 9, 28, 0.18);
    position: relative;
}

pre::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--brand-gradient);
    border-radius: 12px 12px 0 0;
}

code {
    font-family: 'Ubuntu Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 0.98em;
    background-color: var(--purple-dim);
    color: var(--purple);
    padding: 0.1em 0.45em;
    border-radius: 6px;
    border: 1px solid var(--purple-line);
}

pre code {
    background-color: transparent !important;
    padding: 0 !important;
    border: none;
    color: #e6e6ea;
    display: block;
    font-size: 0.95rem;
}

/* Copy Button */
.copy-button {
    position: absolute;
    top: 0.8rem;
    right: 0.8rem;
    background-color: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.18);
    color: rgba(255, 255, 255, 0.8);
    padding: 0.35rem 0.6rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.2s ease;
    z-index: 10;
}

.copy-button:hover {
    background-color: var(--orange);
    border-color: var(--orange);
    color: white;
}

.copy-button.copied {
    background-color: rgba(26, 127, 55, 0.3);
    border-color: #2ea043;
    color: #7ee2a8;
}

/* Lists */
ul, ol {
    margin: 1rem 0 1rem 1.75rem;
}

li {
    margin: 0.45rem 0;
}

li::marker {
    color: var(--orange);
}

ol > li::marker {
    font-weight: 700;
}

/* Module Content */
.module-content {
    background: var(--surface);
    padding: 3rem;
    margin: 2.5rem 0 2rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.module-content h1:first-child {
    margin-top: 0;
    padding-bottom: 1rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    position: relative;
}

.module-content h1:first-child::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -2px;
    width: 120px;
    height: 3px;
    border-radius: 3px;
    background: var(--brand-gradient);
}

.module-content hr {
    border: none;
    height: 1px;
    background: var(--border-color);
    margin: 2.5rem 0;
}

.module-content img {
    max-width: 100%;
    border-radius: 12px;
}

/* Module Navigation */
.module-nav {
    display: flex;
    justify-content: space-between;
    margin: 2rem 0;
    gap: 1rem;
}

.nav-button {
    display: inline-block;
    padding: 0.8rem 1.6rem;
    background-color: var(--surface);
    color: var(--purple) !important;
    border: 1px solid var(--purple-line);
    text-decoration: none !important;
    border-radius: 999px;
    font-weight: 700;
    transition: all 0.2s;
    box-shadow: var(--shadow);
}

.nav-button:hover {
    background-color: var(--purple);
    border-color: var(--purple);
    color: white !important;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.module-nav .nav-button:last-child:not(:first-child) {
    background-color: var(--purple);
    border-color: var(--purple);
    color: white !important;
    margin-left: auto;
}

.module-nav .nav-button:last-child:not(:first-child):hover {
    background-color: var(--orange);
    border-color: var(--orange);
}

/* CTA Button */
.cta {
    text-align: center;
    margin: 3rem 0;
}

.cta-button {
    display: inline-block;
    padding: 1rem 2.4rem;
    background: var(--orange);
    color: white !important;
    text-decoration: none !important;
    border-radius: 999px;
    font-size: 1.2rem;
    font-weight: 900;
    transition: all 0.2s;
    box-shadow: 0 10px 24px rgba(233, 70, 0, 0.3);
}

.cta-button:hover {
    background: var(--orange-600);
    transform: translateY(-2px);
    box-shadow: 0 14px 30px rgba(233, 70, 0, 0.38);
}

/* Footer */
footer {
    position: relative;
    background-color: var(--ink);
    color: rgba(255, 255, 255, 0.8);
    padding: 2.5rem 0;
    margin-top: 4rem;
    text-align: center;
}

footer::before {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    height: 3px;
    background: var(--brand-gradient);
}

footer p {
    margin: 0.5rem 0;
}

footer p:first-child {
    color: white;
    font-weight: 900;
    font-size: 1.1rem;
}

footer strong {
    color: white;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 1rem;
    flex-wrap: wrap;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8) !important;
    text-decoration: none !important;
    transition: color 0.2s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.footer-links a:hover {
    color: var(--orange) !important;
}

/* Tables */
table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin: 1.5rem 0;
    background: var(--surface);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    font-size: 0.95rem;
}

table th,
table td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    vertical-align: top;
}

table th {
    background-color: var(--ink);
    color: white;
    font-weight: 700;
}

table tr:last-child td {
    border-bottom: none;
}

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

table tbody tr:hover {
    background-color: var(--purple-dim);
}

/* Blockquotes */
blockquote {
    border: 1px solid var(--purple-line);
    border-left: 4px solid var(--purple);
    padding: 1rem 1.5rem;
    margin: 1.5rem 0;
    background-color: var(--purple-dim);
    border-radius: 0 12px 12px 0;
}

blockquote > :last-child {
    margin-bottom: 0;
}

/* Strong/Bold emphasis */
strong {
    color: var(--ink);
    font-weight: 700;
}

/* Track hint on the index page */
.track-hint {
    background: var(--orange-dim);
    border: 1px solid rgba(233, 70, 0, 0.2);
    border-left: 4px solid var(--orange);
    border-radius: 0 12px 12px 0;
    padding: 0.9rem 1.2rem;
    margin: 1.5rem 0 0;
    font-size: 0.95rem;
}

.track-hint i {
    color: var(--orange);
}

/* Track Blocks
   Without JavaScript every track is shown, each under its own label, so the
   page still reads correctly. The switcher injects a rule that hides the
   tracks the reader did not pick. */
.track-block {
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--orange);
    border-radius: 0 12px 12px 0;
    padding: 1rem 1.5rem 0.5rem;
    margin: 1.5rem 0;
    background: #fcfcfd;
}

.track-block > .track-label {
    display: inline-block;
    margin: 0 0 0.5rem 0;
    padding: 0.2rem 0.8rem;
    background-color: var(--orange);
    color: white;
    border-radius: 999px;
    font-family: 'Ubuntu Mono', ui-monospace, monospace;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.track-block > pre:first-of-type {
    margin-top: 0.5rem;
}

.track-block > :last-child {
    margin-bottom: 1rem;
}

/* Video Grid */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.video-container {
    background: var(--surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 1rem;
    box-shadow: var(--shadow);
}

.video-container h4 {
    margin-top: 0;
    margin-bottom: 1rem;
    color: var(--ink);
}

.video-container iframe {
    width: 100%;
    aspect-ratio: 16 / 9;
    border-radius: 10px;
    margin-bottom: 1rem;
}

.video-container p {
    margin: 0;
    color: var(--text-light);
    font-size: 0.95rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        font-size: 16px;
    }

    .container {
        padding: 0 16px;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .hero {
        padding: 2.5rem 1.5rem;
    }

    .hero h1 {
        font-size: 2.1rem;
    }

    section {
        padding: 1.5rem;
    }

    .modules-grid,
    .video-grid {
        grid-template-columns: 1fr;
    }

    .module-content {
        padding: 1.5rem;
    }

    .module-content table {
        display: block;
        overflow-x: auto;
    }

    .module-nav {
        flex-direction: column;
    }

    .nav-button {
        text-align: center;
    }

    .module-nav .nav-button:last-child:not(:first-child) {
        margin-left: 0;
    }

    .navbar {
        position: static;
    }

    .navbar .container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.75rem 1rem;
    }

    .lang-switch,
    .track-switch {
        border-left: none;
        padding-left: 0;
    }

    .track-block {
        padding: 1rem 1rem 0.5rem;
    }
}

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

.mb-1 {
    margin-bottom: 1rem;
}

.mb-2 {
    margin-bottom: 2rem;
}

.mt-1 {
    margin-top: 1rem;
}

.mt-2 {
    margin-top: 2rem;
}