/*
 * Shared lesson theme for every course track (math, python, c, cpp).
 *
 * Loaded after each track's own assets/style.css by
 * scripts/postprocess-course-html.mjs. The tracks already share variable names,
 * so most of the work is resetting those variables to the main site's palette
 * (app/globals.css). Selectors start with html[data-theme] so they win over
 * the track rules without !important; the inline head script always sets it.
 */

html[data-theme="light"],
html[data-theme="light"] body {
    --dm-bg: #fbf9f6;
    --dm-bg-soft: #f6f3ee;
    --dm-surface: #ffffff;
    --dm-raised: #ece7df;
    --dm-border: #e7e1d7;
    --dm-text: #1a1917;
    --dm-text-2: #4d4a45;
    --dm-muted: #8c8882;
    --dm-ink: #1a1917;
    --dm-mint: #10b981;
    --dm-mint-soft: rgba(16, 185, 129, 0.1);
    --dm-code-bg: #efeae1;
    --dm-pre-bg: #f6f3ee;
    --dm-header-bg: rgba(251, 249, 246, 0.88);
    --dm-shadow: 0 1px 2px rgba(26, 25, 23, 0.04), 0 4px 16px rgba(26, 25, 23, 0.05);
    --dm-tok-comment: #8c8882;
    --dm-tok-keyword: #9d174d;
    --dm-tok-string: #047857;
    --dm-tok-number: #b45309;
    --dm-tok-function: #1d4ed8;
    --dm-tok-type: #6d28d9;
    --dm-tok-punct: #57534e;
    color-scheme: light;
}

html[data-theme="dark"],
html[data-theme="dark"] body {
    --dm-bg: #141413;
    --dm-bg-soft: #1a1917;
    --dm-surface: #1f1e1c;
    --dm-raised: #2a2825;
    --dm-border: #2f2d29;
    --dm-text: #ece9e4;
    --dm-text-2: #c4bfb6;
    --dm-muted: #8f8a82;
    --dm-ink: #f5f3ef;
    --dm-mint: #6ee7b7;
    --dm-mint-soft: rgba(110, 231, 183, 0.12);
    --dm-code-bg: #262420;
    --dm-pre-bg: #1b1a18;
    --dm-header-bg: rgba(20, 20, 19, 0.85);
    --dm-shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 4px 16px rgba(0, 0, 0, 0.25);
    --dm-tok-comment: #8f8a82;
    --dm-tok-keyword: #f9a8d4;
    --dm-tok-string: #86efac;
    --dm-tok-number: #fcd34d;
    --dm-tok-function: #93c5fd;
    --dm-tok-type: #c4b5fd;
    --dm-tok-punct: #a8a29e;
    color-scheme: dark;
}

/* Map the shared palette onto the variables every track's stylesheet uses. */
html[data-theme],
html[data-theme] body {
    --bg-color: var(--dm-bg);
    --sidebar-bg: var(--dm-bg-soft);
    --sidebar-border: var(--dm-border);
    --text-primary: var(--dm-text);
    --text-secondary: var(--dm-text-2);
    --text-muted: var(--dm-muted);
    --border-color: var(--dm-border);
    --border-light: var(--dm-border);
    --accent-color: var(--dm-ink);
    --accent-hover: var(--dm-text-2);
    --accent-light: var(--dm-raised);
    --code-bg: var(--dm-code-bg);
    --pre-bg: var(--dm-pre-bg);
    --pre-border: var(--dm-border);
    --pre-text: var(--dm-text);
    --font-serif: Georgia, Cambria, "Times New Roman", Times, serif;
    --font-sans: Inter, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    --font-mono: "JetBrains Mono", "Fira Code", ui-monospace, SFMono-Regular, Menlo, monospace;
}

html[data-theme] {
    background: var(--dm-bg);
}

html[data-theme] body {
    background: var(--dm-bg);
    color: var(--dm-text);
    font-family: var(--font-sans);
}

/* ---------- Sidebar ---------- */

html[data-theme] aside.sidebar {
    background: var(--dm-bg-soft);
    border-right: 1px solid var(--dm-border);
}

html[data-theme] .sidebar-brand {
    display: flex;
    align-items: center;
    gap: 0.55rem;
    margin-bottom: 1.25rem;
    color: var(--dm-ink);
    text-decoration: none;
    font-family: var(--font-sans);
    font-size: 15px;
    font-weight: 650;
    letter-spacing: -0.01em;
}

html[data-theme] .dm-logo {
    width: 16px;
    height: 16px;
    border-radius: 5px;
    background: var(--dm-ink);
    flex-shrink: 0;
}

/* Math's course title under the brand. */
html[data-theme] .brand a {
    color: var(--dm-text);
    font-family: var(--font-display, Georgia, serif);
}

html[data-theme] .search-input {
    background: var(--dm-surface);
    border: 1px solid var(--dm-border);
    border-radius: 10px;
    color: var(--dm-text);
    font-family: var(--font-sans);
}

html[data-theme] .search-input:focus {
    border-color: var(--dm-muted);
    box-shadow: 0 0 0 3px var(--dm-mint-soft);
    outline: none;
}

html[data-theme] .search-results {
    background: var(--dm-surface);
    border: 1px solid var(--dm-border);
    box-shadow: var(--dm-shadow);
}

html[data-theme] .search-result-item:hover {
    background: var(--dm-raised);
}

/* Section and phase headings in the course menus. */
html[data-theme] .menu-group-title,
html[data-theme] .menu-phase-title {
    color: var(--dm-muted);
    font-family: var(--font-sans);
    font-size: 0.7rem;
    font-weight: 650;
    letter-spacing: 0.08em;
}

/* Lesson links: python/c/cpp use .menu-items, math uses chapters + subtopics. */
html[data-theme] .menu-items a,
html[data-theme] .chapter-row a,
html[data-theme] .subtopics-list a {
    color: var(--dm-text-2);
    font-family: var(--font-sans);
    border-radius: 8px;
}

html[data-theme] .menu-items a:hover,
html[data-theme] .chapter-row:hover,
html[data-theme] .subtopics-list a:hover {
    background: var(--dm-raised);
    color: var(--dm-text);
}

html[data-theme] .menu-items li.active a,
html[data-theme] .subtopics-list li.active a,
html[data-theme] .chapter-row a.active {
    background: var(--dm-raised);
    color: var(--dm-ink);
    font-weight: 600;
    box-shadow: inset 2px 0 0 var(--dm-mint);
}

html[data-theme] .menu-items {
    padding-left: 0.5rem;
}

/* Math indented chapter rows ~3rem past their phase heading. */
html[data-theme] .menu-chapters {
    padding-left: 0;
}

html[data-theme] .chapter-row {
    padding-left: 0.25rem;
    border-radius: 8px;
}

html[data-theme] .subtopics-list {
    padding-left: 0.75rem;
}

html[data-theme] .sidebar-footer {
    border-top: 1px solid var(--dm-border);
}

html[data-theme] .footer-nav a {
    color: var(--dm-muted);
}

html[data-theme] .footer-nav a:hover {
    color: var(--dm-text);
}

.dm-sidebar-site {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem 0.9rem;
    margin-bottom: 0.75rem;
    font-family: var(--font-sans);
    font-size: 0.8rem;
}

.dm-sidebar-site a {
    color: var(--dm-muted);
    text-decoration: none;
}

.dm-sidebar-site a:hover {
    color: var(--dm-text);
}

/* ---------- Header with the site nav ---------- */

html[data-theme] header.top-header {
    background: var(--dm-header-bg);
    border-bottom: 1px solid var(--dm-border);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
}

.dm-sitenav {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    margin-left: auto;
    font-family: var(--font-sans);
    font-size: 0.875rem;
}

.dm-sitenav a,
.dm-sitenav-courses a {
    padding: 0.4rem 0.65rem;
    border-radius: 999px;
    color: var(--dm-text-2);
    text-decoration: none;
    white-space: nowrap;
    transition: background-color 0.15s ease, color 0.15s ease;
}

.dm-sitenav a:hover {
    background: var(--dm-raised);
    color: var(--dm-text);
}

.dm-sitenav a[aria-current] {
    background: var(--dm-ink);
    color: var(--dm-bg);
}

.dm-sitenav-home {
    font-weight: 650;
}

.dm-sitenav-courses {
    display: flex;
    gap: 0.15rem;
}

.dm-sitenav-sep {
    width: 1px;
    height: 1.1rem;
    margin: 0 0.35rem;
    background: var(--dm-border);
}

.dm-theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.25rem;
    height: 2.25rem;
    margin-left: 0.35rem;
    padding: 0;
    border: 1px solid var(--dm-border);
    border-radius: 999px;
    background: var(--dm-surface);
    color: var(--dm-text);
    cursor: pointer;
    flex-shrink: 0;
}

.dm-theme-toggle:hover {
    background: var(--dm-raised);
}

.dm-theme-toggle:focus-visible,
.dm-sitenav a:focus-visible {
    outline: 2px solid var(--dm-mint);
    outline-offset: 2px;
}

.dm-theme-toggle svg {
    width: 1.05rem;
    height: 1.05rem;
}

html[data-theme="light"] .dm-icon-sun,
html[data-theme="dark"] .dm-icon-moon {
    display: none;
}

/* ---------- Article ---------- */

html[data-theme] .category-indicator {
    color: var(--dm-muted);
    font-family: var(--font-sans);
    font-weight: 600;
    letter-spacing: 0.1em;
}

html[data-theme] .markdown-body {
    color: var(--dm-text);
    font-family: var(--font-sans);
    font-size: 1.0625rem;
    line-height: 1.75;
}

html[data-theme] .markdown-body p,
html[data-theme] .markdown-body li {
    font-family: var(--font-sans);
    color: var(--dm-text);
}

html[data-theme] .markdown-body h1,
html[data-theme] .lecture-title {
    font-family: var(--font-serif);
    font-weight: 400;
    letter-spacing: -0.03em;
    color: var(--dm-ink);
    border-bottom: none;
}

html[data-theme] .markdown-body h2,
html[data-theme] .markdown-body h3,
html[data-theme] .markdown-body h4 {
    font-family: var(--font-serif);
    font-weight: 400;
    letter-spacing: -0.02em;
    color: var(--dm-ink);
}

html[data-theme] .markdown-body h2 {
    border-bottom: 1px solid var(--dm-border);
    padding-bottom: 0.5rem;
}

/* The tracks drew a short accent bar under each h2 that sat off the rule. */
html[data-theme] .markdown-body h2::after {
    display: none;
}

/* Most math lessons open with a leftover rule above the title. */
html[data-theme] .markdown-body > hr:first-child {
    display: none;
}

html[data-theme] .markdown-body strong {
    color: var(--dm-ink);
}

html[data-theme] .markdown-body a,
html[data-theme] .markdown-body a:visited {
    color: var(--dm-ink);
    text-decoration: underline;
    text-decoration-color: var(--dm-mint);
    text-decoration-thickness: 1.5px;
    text-underline-offset: 3px;
}

html[data-theme] .markdown-body a:hover {
    color: var(--dm-text-2);
}

/* One bullet style everywhere (python's index showed a square and a dot). */
html[data-theme] .markdown-body ul {
    list-style: none;
}

html[data-theme] .markdown-body ul li::before {
    background: var(--dm-muted);
}

html[data-theme] .markdown-body ol li::marker {
    color: var(--dm-muted);
}

html[data-theme] .markdown-body blockquote {
    background: var(--dm-bg-soft);
    border-left: 3px solid var(--dm-mint);
    color: var(--dm-text-2);
    border-radius: 0 10px 10px 0;
}

html[data-theme] .markdown-body .insight-box {
    background: var(--dm-mint-soft);
    border: 1px solid var(--dm-border);
}

html[data-theme] .markdown-body hr {
    background: var(--dm-border);
    border-color: var(--dm-border);
}

html[data-theme] .markdown-body table {
    border: 1px solid var(--dm-border);
    box-shadow: none;
}

html[data-theme] .markdown-body th {
    background: var(--dm-bg-soft);
    color: var(--dm-ink);
    font-family: var(--font-sans);
}

html[data-theme] .markdown-body td,
html[data-theme] .markdown-body th {
    border-color: var(--dm-border);
}

html[data-theme] .markdown-body tr:nth-child(even) td {
    background: transparent;
}

html[data-theme] .markdown-body tr:hover td {
    background: var(--dm-bg-soft);
}

/* ---------- Code ---------- */

html[data-theme] .markdown-body :not(pre) > code {
    background: var(--dm-code-bg);
    color: var(--dm-ink);
    border: none;
    border-radius: 5px;
    font-family: var(--font-mono);
    font-size: 0.86em;
}

html[data-theme] .markdown-body pre,
html[data-theme] pre[class*="language-"] {
    background: var(--dm-pre-bg);
    border: 1px solid var(--dm-border);
    border-radius: 12px;
    box-shadow: none;
    text-shadow: none;
}

html[data-theme] .markdown-body pre code,
html[data-theme] code[class*="language-"],
html[data-theme] pre[class*="language-"] {
    color: var(--dm-text);
    /* Tight enough that box-drawing diagrams join up. */
    line-height: 1.55;
    font-family: var(--font-mono);
    text-shadow: none;
}

/* As an inline box the code inherited the pre's prose line height. */
html[data-theme] .markdown-body pre > code {
    display: block;
}

html[data-theme] .markdown-body pre::before {
    color: var(--dm-muted);
}

/* Prism token colours: half the pages load prism.css, half prism-tomorrow. */
html[data-theme] .token.comment,
html[data-theme] .token.prolog,
html[data-theme] .token.doctype,
html[data-theme] .token.cdata {
    color: var(--dm-tok-comment);
    font-style: italic;
}

html[data-theme] .token.punctuation,
html[data-theme] .token.operator {
    color: var(--dm-tok-punct);
    background: none;
}

html[data-theme] .token.keyword,
html[data-theme] .token.atrule,
html[data-theme] .token.important,
html[data-theme] .token.directive,
html[data-theme] .token.macro {
    color: var(--dm-tok-keyword);
}

html[data-theme] .token.string,
html[data-theme] .token.char,
html[data-theme] .token.attr-value,
html[data-theme] .token.regex,
html[data-theme] .token.inserted {
    color: var(--dm-tok-string);
    background: none;
}

html[data-theme] .token.number,
html[data-theme] .token.boolean,
html[data-theme] .token.constant,
html[data-theme] .token.symbol,
html[data-theme] .token.deleted {
    color: var(--dm-tok-number);
}

html[data-theme] .token.function,
html[data-theme] .token.property,
html[data-theme] .token.tag {
    color: var(--dm-tok-function);
}

html[data-theme] .token.class-name,
html[data-theme] .token.builtin,
html[data-theme] .token.variable,
html[data-theme] .token.selector,
html[data-theme] .token.attr-name {
    color: var(--dm-tok-type);
}

html[data-theme] .copy-code-btn {
    background: var(--dm-surface);
    border: 1px solid var(--dm-border);
    color: var(--dm-text-2);
}

html[data-theme] .copy-code-btn:hover {
    background: var(--dm-raised);
    color: var(--dm-text);
}

/* ---------- "On this page" (built from the old table-of-contents boxes) ---------- */

.dm-toc {
    margin: 0 0 2.5rem;
    border: 1px solid var(--dm-border);
    border-radius: 12px;
    background: var(--dm-bg-soft);
    font-family: var(--font-sans);
}

.dm-toc > summary {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.85rem 1.1rem;
    cursor: pointer;
    list-style: none;
    color: var(--dm-text);
    font-size: 0.9rem;
    font-weight: 600;
}

.dm-toc > summary::-webkit-details-marker {
    display: none;
}

.dm-toc > summary::before {
    content: "";
    width: 0.45rem;
    height: 0.45rem;
    border-right: 1.5px solid currentColor;
    border-bottom: 1.5px solid currentColor;
    transform: rotate(-45deg);
    transition: transform 0.15s ease;
}

.dm-toc[open] > summary::before {
    transform: rotate(45deg);
}

.dm-toc-count {
    color: var(--dm-muted);
    font-weight: 400;
}

html[data-theme] .dm-toc .toc-card,
html[data-theme] .dm-toc .toc-container {
    margin: 0;
    padding: 0 1.1rem 1rem 2rem;
    border: none;
    background: none;
    box-shadow: none;
}

html[data-theme] .dm-toc ul,
html[data-theme] .dm-toc ol {
    margin: 0.25rem 0;
    padding-left: 1rem;
    list-style: disc;
}

html[data-theme] .dm-toc li {
    margin: 0.2rem 0;
    padding-left: 0;
    font-size: 0.92rem;
    line-height: 1.5;
}

html[data-theme] .dm-toc li::before {
    display: none;
}

html[data-theme] .dm-toc li::marker {
    color: var(--dm-muted);
}

html[data-theme] .dm-toc a,
html[data-theme] .dm-toc a:visited {
    color: var(--dm-text-2);
    text-decoration: none;
}

html[data-theme] .dm-toc a:hover {
    color: var(--dm-ink);
    text-decoration: underline;
    text-decoration-color: var(--dm-mint);
}

/* ---------- Course home: module cards (python and c++ homes) ---------- */

.dm-modules {
    display: grid;
    gap: 1rem;
    margin: 1.5rem 0 2.5rem;
}

.dm-module {
    padding: 1.25rem 1.4rem 1.1rem;
    border: 1px solid var(--dm-border);
    border-radius: 14px;
    background: var(--dm-surface);
}

html[data-theme] .dm-module h3 {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 1rem;
    margin: 0 0 0.75rem;
    font-size: 1.35rem;
}

.dm-module-count {
    color: var(--dm-muted);
    font-family: var(--font-sans);
    font-size: 0.8rem;
    letter-spacing: 0;
    white-space: nowrap;
}

html[data-theme] .dm-module ol {
    margin: 0;
    padding-left: 1.6rem;
    columns: 2 16rem;
    column-gap: 2rem;
}

html[data-theme] .dm-module li {
    margin: 0 0 0.35rem;
    break-inside: avoid;
    font-size: 0.95rem;
    line-height: 1.5;
}

html[data-theme] .dm-module li::marker {
    color: var(--dm-muted);
    font-size: 0.85em;
    font-variant-numeric: tabular-nums;
}

html[data-theme] .dm-module a,
html[data-theme] .dm-module a:visited {
    color: var(--dm-text);
    text-decoration: none;
}

html[data-theme] .dm-module a:hover {
    color: var(--dm-ink);
    text-decoration: underline;
    text-decoration-color: var(--dm-mint);
}

/* ---------- Previous / next ---------- */

html[data-theme] .pagination-container {
    border-top: 1px solid var(--dm-border);
}

html[data-theme] .pag-btn {
    background: var(--dm-surface);
    border: 1px solid var(--dm-border);
    border-radius: 12px;
    box-shadow: none;
}

html[data-theme] .pag-btn:hover {
    border-color: var(--dm-muted);
    box-shadow: var(--dm-shadow);
}

html[data-theme] .pag-label {
    color: var(--dm-muted);
    font-family: var(--font-sans);
}

html[data-theme] .pag-title {
    color: var(--dm-ink);
    font-family: var(--font-serif);
}

/* ---------- Small screens ---------- */

/* Below 1024px the tracks swap the sidebar for a drawer; the nav keeps
   only the theme button and the drawer's footer carries the site links. */
@media (max-width: 1024px) {
    .dm-sitenav > a,
    .dm-sitenav-courses,
    .dm-sitenav-sep {
        display: none;
    }

    .dm-sitenav {
        margin-left: auto;
        margin-right: 0.25rem;
    }

    html[data-theme] header.top-header {
        background: var(--dm-header-bg);
    }

    /* An inline display:none on every page hid the course name on phones. */
    html[data-theme] .mobile-brand {
        display: inline-flex !important;
        align-items: center;
        gap: 0.5rem;
        color: var(--dm-ink) !important;
        font-family: var(--font-sans);
        font-size: 0.95rem;
        font-weight: 650 !important;
        min-width: 0;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        order: -1;
    }

    html[data-theme] .mobile-brand::before {
        content: "";
        width: 14px;
        height: 14px;
        border-radius: 4px;
        background: var(--dm-ink);
        flex-shrink: 0;
    }

    html[data-theme] .markdown-body h1,
    html[data-theme] .lecture-title {
        font-size: clamp(2rem, 1.4rem + 3vw, 2.5rem);
        line-height: 1.15;
    }

    html[data-theme] .markdown-body h2 {
        font-size: 1.6rem;
    }

    html[data-theme] .mobile-nav-toggle {
        color: var(--dm-text);
    }
}

@media (min-width: 1025px) and (max-width: 1280px) {
    .dm-sitenav-home,
    .dm-sitenav-home + .dm-sitenav-sep {
        display: none;
    }
}

@media print {
    .dm-sitenav,
    .dm-toc > summary {
        display: none;
    }
}