/* appsyoucanmake.com — developer-textbook meets Apple aesthetic. */

/* ====================================================================
   Design tokens
   ==================================================================== */

:root {
    --bg:        #F8F9FF;   /* barely-blue white */
    --bg-deep:   #ECEEF8;   /* code block / card background */
    --bg-card:   #FFFFFF;   /* raised card surface */
    --ink:       #0F1117;   /* near-black */
    --ink-soft:  #3D4160;
    --ink-mute:  #7A7E9A;

    /* APPS · YOU · CAN · MAKE */
    --aycm-a:    #2B7F31;   /* green   — Apps */
    --aycm-y:    #2D6FB1;   /* blue    — You */
    --aycm-c:    #B8364A;   /* coral   — Can */
    --aycm-m:    #A8551A;   /* orange  — Make */

    --accent:    #2D6FB1;   /* primary = You blue */
    --accent-2:  #B8364A;   /* secondary = Can coral */

    --rule:      rgba(15, 17, 23, 0.12);
    --rule-hard: #0F1117;
    --shadow:    #BFBFBF;   /* 25% grey — hard offset shadows */

    --display: -apple-system, "SF Pro Display", "Helvetica Neue", Arial, sans-serif;
    --sans:    -apple-system, "SF Pro Text", BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
    --mono:    "SF Mono", "JetBrains Mono", ui-monospace, Menlo, Consolas, monospace;

    --max:      44rem;
    --max-wide: 68rem;

    --radius: 6px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg:        #0F1117;
        --bg-deep:   #181C28;
        --bg-card:   #181C28;
        --ink:       #E8EBF5;
        --ink-soft:  #A8ADBE;
        --ink-mute:  #5C607A;

        --aycm-a:    #78C445;   /* green  — Apps  (exact logo) */
        --aycm-y:    #47A2F1;   /* blue   — You   (exact logo) */
        --aycm-c:    #F7788A;   /* coral  — Can   (exact logo) */
        --aycm-m:    #FFA35F;   /* orange — Make  (exact logo) */

        --accent:    #6FA8E0;
        --accent-2:  #E07490;

        --rule:      rgba(232, 235, 245, 0.12);
        --rule-hard: #E8EBF5;
        --shadow:    #404040;   /* 75% grey */
    }
}

/* ====================================================================
   Reset + base
   ==================================================================== */

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--ink);
    font-family: var(--sans);
    font-size: 17px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

::selection { background: var(--accent); color: #fff; }

a {
    color: var(--accent);
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 3px;
    transition: color 80ms linear, opacity 80ms linear;
}
a:hover { opacity: 0.75; text-decoration-thickness: 2px; }

img { max-width: 100%; height: auto; display: block; }

h1, h2, h3, h4 {
    font-family: var(--display);
    font-weight: 700;
    line-height: 1.15;
    margin: 0 0 0.4em;
    color: var(--ink);
    letter-spacing: -0.015em;
}
h1 { font-size: clamp(2.2rem, 5vw, 3.2rem); }
h2 { font-size: 1.55rem; margin-top: 2.2em; }
h3 { font-size: 1.2rem; margin-top: 1.6em; }
h4 { font-size: 1rem; margin-top: 1.2em; }

p, ul, ol { margin: 0 0 1em; }

blockquote {
    margin: 1.5em 0;
    padding: 1em 1.2em;
    background: var(--bg-deep);
    border-left: 3px solid var(--accent);
    color: var(--ink-soft);
    font-style: italic;
    border-radius: 0 var(--radius) var(--radius) 0;
}

hr { border: 0; border-top: 1px solid var(--rule); margin: 2.5em 0; }

/* ====================================================================
   Code — the primary UX surface
   ==================================================================== */

code, pre {
    font-family: var(--mono);
    font-size: 0.9em;
}

pre {
    position: relative;
    background: var(--bg-deep);
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    padding: 1.2em 1.2em 1.2em 1.4em;
    overflow-x: auto;
    line-height: 1.55;
    margin: 1.5em 0;
    tab-size: 4;
    -moz-tab-size: 4;
}

/* Language label */
pre[class*="language-"]::before {
    content: attr(data-lang);
    position: absolute;
    top: 0.5em;
    right: 0.7em;
    font-family: var(--mono);
    font-size: 0.7em;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--ink-mute);
    user-select: none;
}

/* Copy button (injected by JS) */
.copy-btn {
    position: absolute;
    top: 0.45em;
    right: 0.5em;
    padding: 0.2em 0.6em;
    background: var(--bg-card);
    border: 1px solid var(--rule);
    border-radius: 4px;
    font-family: var(--mono);
    font-size: 0.7em;
    color: var(--ink-mute);
    cursor: pointer;
    opacity: 0;
    transition: opacity 120ms;
}
pre:hover .copy-btn { opacity: 1; }
.copy-btn:hover { color: var(--accent); border-color: var(--accent); }
.copy-btn.copied { color: var(--aycm-a); border-color: var(--aycm-a); }

code {
    background: var(--bg-deep);
    padding: 0.15em 0.4em;
    border-radius: 4px;
    border: 1px solid var(--rule);
}
pre code { background: transparent; padding: 0; border: 0; border-radius: 0; }

/* Tables */
table { border-collapse: collapse; margin: 1.5em 0; width: 100%; }
th, td { border-bottom: 1px solid var(--rule); padding: 0.5em 0.75em; text-align: left; }
th { font-weight: 600; border-bottom: 2px solid var(--rule-hard); font-size: 0.9em; text-transform: uppercase; letter-spacing: 0.04em; color: var(--ink-soft); }

/* Skip link */
.skip-link { position: absolute; left: -9999px; }
.skip-link:focus { left: 0.5rem; top: 0.5rem; padding: 0.4em 0.8em; background: var(--ink); color: var(--bg); z-index: 200; border-radius: var(--radius); text-decoration: none; }

/* ====================================================================
   APPS · YOU · CAN · MAKE wordmark colors
   ==================================================================== */

.aycm-a { color: var(--aycm-a); }
.aycm-y { color: var(--aycm-y); }
.aycm-c { color: var(--aycm-c); }
.aycm-m { color: var(--aycm-m); }

/* ====================================================================
   Header
   ==================================================================== */

.site-header {
    background: var(--bg);
    border-bottom: 1px solid var(--rule);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-bar {
    max-width: var(--max-wide);
    margin: 0 auto;
    padding: 0 1.5rem;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.site-mark {
    text-decoration: none;
    color: var(--ink);
    font-family: var(--display);
    font-size: 1.05rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    white-space: nowrap;
    flex-shrink: 0;
}
.site-mark:hover { opacity: 1; text-decoration: none; }
.site-mark:hover .aycm-a { color: var(--aycm-a); }
.site-mark:hover .aycm-y { color: var(--aycm-y); }
.site-mark:hover .aycm-c { color: var(--aycm-c); }
.site-mark:hover .aycm-m { color: var(--aycm-m); }

.nav-links {
    list-style: none; margin: 0; padding: 0;
    display: flex; align-items: center;
    gap: 0.2rem;
}
.nav-links a {
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--ink-soft);
    padding: 0.35em 0.7em;
    border-radius: var(--radius);
    transition: background 80ms, color 80ms;
}
.nav-links a:hover { background: var(--bg-deep); color: var(--ink); opacity: 1; }
.nav-links a[aria-current="page"] { color: var(--accent); background: var(--bg-deep); }

/* CTA nav item */
.nav-links a.nav-cta {
    background: var(--accent);
    color: #fff;
    font-weight: 600;
    padding: 0.35em 0.9em;
}
.nav-links a.nav-cta:hover { opacity: 0.85; background: var(--accent); color: #fff; }

/* ====================================================================
   Layout
   ==================================================================== */

.site-main {
    max-width: var(--max);
    margin: 0 auto;
    padding: 3.5rem 1.5rem 5rem;
}

.site-main--wide {
    max-width: var(--max-wide);
    margin: 0 auto;
    padding: 3.5rem 1.5rem 5rem;
}

/* ====================================================================
   Hero — homepage
   ==================================================================== */

.hero {
    padding: 3.5rem 1.5rem 0;
    max-width: var(--max-wide);
    margin: 0 auto;
}

.hero-eyebrow {
    font-family: var(--mono);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.14em;
    color: var(--ink-mute);
    margin: 0 0 0.8em;
}

.hero-wordmark {
    font-family: var(--display);
    font-size: clamp(2.8rem, 7vw, 4.5rem);
    font-weight: 800;
    line-height: 1.05;
    letter-spacing: -0.03em;
    margin: 0 0 0.45em;
}
.hero-wordmark span { display: inline-block; }
/* Hero is large display text (44px+, weight 800), so WCAG's 3:1 large-text
   threshold applies — a truer orange than the 4.5:1 small-text value above.
   3.79:1. Dark mode already uses the exact logo color, so no override needed. */
.hero-wordmark .aycm-m { color: #C4661E; }
@media (prefers-color-scheme: dark) {
    .hero-wordmark .aycm-m { color: var(--aycm-m); }
}
.hero-wordmark span + span::before { content: " "; }

.hero-tagline {
    font-size: 1.2rem;
    color: var(--ink-soft);
    margin: 0 0 2.5rem;
    max-width: 38rem;
    line-height: 1.5;
}

/* ====================================================================
   Section rhythm
   ==================================================================== */

.home-sections {
    max-width: var(--max-wide);
    margin: 0 auto;
    padding: 3rem 1.5rem 5rem;
}

.home-section {
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid var(--rule);
}
.home-section:first-child { margin-top: 0; border-top: none; padding-top: 0; }

.section-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}
.section-header h2 {
    margin: 0;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    font-weight: 700;
    color: var(--ink-mute);
}
.section-more {
    font-family: var(--mono);
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--ink-mute);
}
.section-more:hover { color: var(--accent); }

/* ====================================================================
   Book cards — shelf layout
   ==================================================================== */

.book-shelf {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1.5rem;
}

.book-card {
    background: var(--bg-card);
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    overflow: hidden;
    transition: box-shadow 120ms, border-color 120ms;
}
.book-card:hover { border-color: var(--accent); box-shadow: 0 4px 20px rgba(0,0,0,0.08); }
.book-card a { text-decoration: none; color: inherit; display: block; }
.book-card a:hover { opacity: 1; }

.book-card-cover {
    aspect-ratio: 3/4;
    background: var(--bg-deep);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}
.book-card-cover img { width: 100%; height: 100%; object-fit: cover; }
.book-card-cover-placeholder {
    font-family: var(--display);
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.1;
    text-align: center;
    padding: 1rem;
}

.book-card-body { padding: 1rem; }
.book-card-body h3 { font-size: 1rem; margin: 0 0 0.3em; line-height: 1.25; }
.book-card-status {
    display: inline-block;
    font-family: var(--mono);
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    padding: 0.15em 0.5em;
    border-radius: 3px;
    background: var(--bg-deep);
    color: var(--ink-mute);
    margin-top: 0.3em;
}
.book-card-status.published { background: rgba(45, 111, 177, 0.12); color: var(--accent); }
.book-card-status.teaser { background: rgba(168, 85, 26, 0.12); color: var(--aycm-m); }

/* ====================================================================
   Home — featured book + Swift Coding Club
   ==================================================================== */

.home-book {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 2.5rem;
    align-items: start;
}
.home-book + .home-book { margin-top: 2.5rem; }

.home-book-cover {
    display: block;
    width: 200px;
    text-decoration: none;
}
.home-book-cover:hover { opacity: 1; }
.home-book-cover img {
    display: block;
    width: 100%;
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    box-shadow: 6px 6px 0 var(--shadow);
    transition: transform 120ms;
}
.home-book-cover:hover img { transform: translate(-2px, -2px); }
.home-book-cover .book-hero-cover-placeholder { width: 200px; }

.home-book-meta { padding-top: 0.2rem; }
.home-book-title {
    font-size: clamp(1.6rem, 3.5vw, 2.2rem);
    font-weight: 800;
    letter-spacing: -0.025em;
    margin: 0 0 0.15em;
}
.home-book-title a { color: inherit; text-decoration: none; }
.home-book-title a:hover { color: var(--accent); opacity: 1; }
.home-book-subtitle {
    font-size: 1.1rem;
    color: var(--ink-soft);
    margin: 0 0 1rem;
}
.home-book-description {
    max-width: 38rem;
    margin: 0 0 1.4rem;
}
.home-book-links {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    margin: 0.8rem 0 0;
    font-size: 0.92rem;
}

.home-club {
    background: var(--bg-card);
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    box-shadow: 6px 6px 0 var(--shadow);
    padding: 1.8rem 2rem 2rem;
    max-width: 44rem;
}
.home-club-body p { margin: 0 0 1em; }
.home-club-body p:first-child { font-size: 1.15rem; }
.home-club .buy-buttons { margin: 1.4rem 0 0; }

@media (max-width: 600px) {
    .home-book { grid-template-columns: 1fr; gap: 1.5rem; }
    .home-book-cover, .home-book-cover .book-hero-cover-placeholder { width: 150px; }
    .home-club { padding: 1.4rem 1.3rem 1.5rem; }
}

/* ====================================================================
   App grid — chapter cards
   ==================================================================== */

.app-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr));
    gap: 1rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

.app-card {
    background: var(--bg-card);
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    overflow: hidden;
    transition: border-color 100ms, box-shadow 100ms;
}
.app-card:hover { border-color: var(--accent); box-shadow: 0 2px 12px rgba(0,0,0,0.07); }
.app-card a { display: block; padding: 1.2rem; text-decoration: none; color: inherit; }
.app-card a:hover { opacity: 1; }

.app-card-chapter {
    font-family: var(--mono);
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent);
    margin: 0 0 0.5em;
}
.app-card h3 { font-size: 1.05rem; margin: 0 0 0.35em; }
.app-card p {
    margin: 0;
    font-size: 0.88rem;
    color: var(--ink-soft);
    line-height: 1.45;
}

.app-card.coming-soon { opacity: 0.5; }
.app-card.coming-soon a { cursor: default; pointer-events: none; }
.app-card.coming-soon .app-card-chapter { color: var(--ink-mute); }

/* ====================================================================
   Post lists
   ==================================================================== */

.post-list { list-style: none; margin: 0; padding: 0; }
.post-list-item {
    padding: 1.2em 0;
    border-bottom: 1px solid var(--rule);
}
.post-list-item:first-child { padding-top: 0; }
.post-list-item:last-child { border-bottom: 0; }
.post-link { display: block; text-decoration: none; color: inherit; }
.post-link:hover { opacity: 1; }
.post-link:hover .post-title { color: var(--accent); }

.post-date {
    display: block;
    font-family: var(--mono);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--ink-mute);
    margin-bottom: 0.3em;
}
.post-title {
    font-family: var(--display);
    font-weight: 700;
    margin: 0 0 0.25em;
    font-size: 1.25rem;
    line-height: 1.2;
    letter-spacing: -0.01em;
    color: var(--ink);
    transition: color 80ms;
}
.post-summary {
    margin: 0;
    color: var(--ink-soft);
    font-size: 0.93rem;
}

.post-type-badge {
    display: inline-block;
    font-family: var(--mono);
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    padding: 0.1em 0.5em;
    border-radius: 3px;
    margin-right: 0.4em;
    vertical-align: middle;
}
.badge-experiment { background: rgba(45,111,177,0.1); color: var(--aycm-y); }
.badge-post       { background: rgba(43,127,49,0.1);  color: var(--aycm-a); }

/* Year groupings */
.post-year { margin-top: 3rem; }
.post-year:first-of-type { margin-top: 1rem; }
.post-year-label {
    font-family: var(--mono);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--ink-mute);
    border-top: 2px solid var(--rule-hard);
    padding-top: 0.6em;
    margin: 0 0 0.8em;
    font-weight: 600;
}

/* ====================================================================
   Article pages
   ==================================================================== */

.page-header { margin: 0 0 2.5rem; }
.page-header h1 { margin: 0 0 0.2em; }

/* Optional page hero (front matter hero_image). White card so the artwork
   reads the same in dark mode; the artwork itself is never recolored. */
.page-hero { margin: 0 0 2.5rem; }
.page-hero img {
    display: block;
    width: 100%;
    height: auto;
    background: #fff;
    border: 1px solid var(--rule);
    border-radius: var(--radius);
}

.sr-only {
    position: absolute;
    width: 1px; height: 1px;
    padding: 0; margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.breadcrumb {
    font-family: var(--mono);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--ink-mute);
    margin: 0 0 1.2em;
    display: flex;
    align-items: center;
    gap: 0.4em;
    flex-wrap: wrap;
}
.breadcrumb a { color: inherit; text-decoration: none; }
.breadcrumb a:hover { color: var(--accent); opacity: 1; }
.breadcrumb-sep { color: var(--rule-hard); opacity: 0.3; }

.post-header { margin: 0 0 2.5rem; padding-bottom: 1.5rem; border-bottom: 2px solid var(--rule-hard); }
.post-meta {
    font-family: var(--mono);
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--ink-mute);
    margin: 0 0 0.6em;
}
.post-header .post-title {
    font-family: var(--display);
    font-size: clamp(1.9rem, 4vw, 2.7rem);
    line-height: 1.1;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin: 0;
    color: var(--ink);
}
.post-lede {
    font-size: 1.15rem;
    color: var(--ink-soft);
    margin: 0.8em 0 0;
    line-height: 1.5;
}

.prose h2 { border-bottom: 1px solid var(--rule); padding-bottom: 0.3em; }
.prose img { margin: 2em 0; border: 1px solid var(--rule); border-radius: var(--radius); }

.post-footer { margin-top: 3rem; padding-top: 1.5rem; border-top: 2px solid var(--rule-hard); }
.post-tags {
    list-style: none; margin: 0 0 1em; padding: 0;
    display: flex; gap: 0.4rem; flex-wrap: wrap;
}
.post-tags li a, .post-tags li {
    font-family: var(--mono);
    font-size: 0.75rem;
    text-transform: lowercase;
    color: var(--ink-mute);
    background: var(--bg-deep);
    padding: 0.2em 0.6em;
    border-radius: 3px;
    text-decoration: none;
    border: 1px solid var(--rule);
}
.post-tags li a:hover { color: var(--accent); border-color: var(--accent); opacity: 1; }

.back-link {
    font-family: var(--mono);
    font-size: 0.82rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--ink-mute);
    text-decoration: none;
}
.back-link:hover { color: var(--accent); opacity: 1; }

/* ====================================================================
   Book page — hero with cover
   ==================================================================== */

.book-hero {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 2.5rem;
    align-items: start;
    margin-bottom: 3rem;
}

.book-hero-cover {
    width: 180px;
    flex-shrink: 0;
}
.book-hero-cover img {
    width: 100%;
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    box-shadow: 6px 6px 0 var(--shadow);
}
.book-hero-cover-placeholder {
    width: 180px;
    aspect-ratio: 3/4;
    background: var(--bg-deep);
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    box-shadow: 6px 6px 0 var(--shadow);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    font-family: var(--display);
    font-weight: 800;
    font-size: 1.3rem;
    letter-spacing: -0.02em;
    line-height: 1.1;
    text-align: center;
    padding: 1rem;
    color: var(--ink);
}

.book-hero-meta { padding-top: 0.2rem; }
.book-hero-meta h1 { margin: 0 0 0.15em; }
.book-hero-subtitle {
    font-size: 1.1rem;
    color: var(--ink-soft);
    margin: 0 0 1.2rem;
}

.buy-buttons { display: flex; gap: 0.6rem; flex-wrap: wrap; margin-bottom: 0.5rem; }
.buy-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4em;
    padding: 0.5em 1.1em;
    background: var(--accent);
    color: #fff;
    font-weight: 600;
    font-size: 0.92rem;
    border-radius: var(--radius);
    text-decoration: none;
    transition: opacity 100ms;
}
.buy-btn:hover { opacity: 0.85; color: #fff; }
.buy-btn.secondary {
    background: var(--bg-deep);
    color: var(--ink);
    border: 1px solid var(--rule);
}
.buy-btn.secondary:hover { border-color: var(--accent); color: var(--accent); }

@media (max-width: 600px) {
    .book-hero { grid-template-columns: 1fr; }
    .book-hero-cover, .book-hero-cover-placeholder { width: 140px; }
}

/* ====================================================================
   Sample app page
   ==================================================================== */

.app-hero { margin-bottom: 2rem; }
.app-hero-chapter {
    font-family: var(--mono);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--accent);
    margin: 0 0 0.4em;
}

.platforms {
    display: flex; gap: 0.4rem; flex-wrap: wrap;
    margin: 0.8rem 0;
    list-style: none; padding: 0;
}
.platform-badge {
    font-family: var(--mono);
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    padding: 0.15em 0.55em;
    border-radius: 3px;
    background: var(--bg-deep);
    color: var(--ink-mute);
    border: 1px solid var(--rule);
}

.download-cta {
    display: inline-flex;
    align-items: center;
    gap: 0.5em;
    padding: 0.6em 1.2em;
    background: var(--bg-card);
    border: 2px solid var(--accent);
    border-radius: var(--radius);
    color: var(--accent);
    font-weight: 600;
    font-size: 0.9rem;
    text-decoration: none;
    margin: 1rem 0;
}
.download-cta:hover { background: var(--accent); color: #fff; opacity: 1; }

/* ====================================================================
   Video embed + video grid
   ==================================================================== */

.video-embed {
    margin: 1.5rem 0 2.5rem;
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid var(--rule);
    aspect-ratio: 16 / 9;
}
.video-embed iframe {
    width: 100%;
    height: 100%;
    display: block;
    border: 0;
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 0 0 3rem;
}

.video-card {
    background: var(--bg-card);
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    display: block;
    transition: border-color 100ms, box-shadow 100ms;
}
.video-card:hover { border-color: var(--accent); box-shadow: 0 2px 12px rgba(0,0,0,0.07); opacity: 1; }

.video-card-thumb {
    position: relative;
    aspect-ratio: 16 / 9;
    background: var(--bg-deep);
    overflow: hidden;
}
.video-card-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }

.video-duration {
    position: absolute;
    bottom: 0.45em;
    right: 0.45em;
    background: rgba(0, 0, 0, 0.76);
    color: #fff;
    font-family: var(--mono);
    font-size: 0.72rem;
    padding: 0.1em 0.45em;
    border-radius: 3px;
    pointer-events: none;
}

.video-duration-inline {
    font-family: var(--mono);
    font-size: 0.75rem;
    color: var(--ink-mute);
    margin-left: 0.6em;
}

.video-card-body { padding: 1rem; }
.video-card-body h2 { font-size: 1rem; margin: 0 0 0.3em; line-height: 1.3; }
.video-card-body p { margin: 0; font-size: 0.88rem; color: var(--ink-soft); line-height: 1.45; }
.video-card-date {
    font-family: var(--mono);
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--ink-mute);
    margin: 0 0 0.4em;
}

.empty-state {
    padding: 4rem 0;
    text-align: center;
    color: var(--ink-soft);
}

/* ====================================================================
   Newsletter CTA
   ==================================================================== */

.newsletter-cta {
    background: var(--bg-deep);
    border: 1px solid var(--rule);
    border-left: 3px solid var(--accent);
    border-radius: 0 var(--radius) var(--radius) 0;
    padding: 1.5rem;
    margin: 3rem 0;
}
.newsletter-cta h3 { margin: 0 0 0.4em; font-size: 1.1rem; }
.newsletter-cta p { margin: 0 0 1em; font-size: 0.93rem; color: var(--ink-soft); }
.newsletter-form { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.newsletter-form input[type="email"] {
    flex: 1;
    min-width: 220px;
    padding: 0.55em 0.85em;
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    background: var(--bg-card);
    color: var(--ink);
    font-family: var(--sans);
    font-size: 0.95rem;
}
.newsletter-form input[type="email"]:focus {
    outline: 2px solid var(--accent);
    outline-offset: 1px;
    border-color: var(--accent);
}
.newsletter-form button {
    padding: 0.55em 1.2em;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: var(--radius);
    font-family: var(--sans);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 80ms;
}
.newsletter-form button:hover { opacity: 0.85; }

/* ====================================================================
   Footer
   ==================================================================== */

.site-footer {
    border-top: 1px solid var(--rule);
    margin-top: 6rem;
    padding: 2.5rem 1.5rem;
    background: var(--bg);
}
.footer-inner {
    max-width: var(--max-wide);
    margin: 0 auto;
    text-align: center;
    color: var(--ink-mute);
    font-size: 0.85rem;
}
.footer-nav, .footer-social {
    display: flex;
    justify-content: center;
    gap: 1.2rem;
    flex-wrap: wrap;
    margin: 0 0 0.6em;
    font-family: var(--mono);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}
.footer-nav a, .footer-social a {
    color: var(--ink-mute);
    text-decoration: none;
}
.footer-nav a:hover, .footer-social a:hover {
    color: var(--accent); opacity: 1;
}
.footer-copy { margin: 0.8em 0 0.2em; }

/* ====================================================================
   404
   ==================================================================== */

.error-page { text-align: center; padding: 4rem 1.5rem; }
.error-code {
    font-family: var(--mono);
    font-size: clamp(5rem, 15vw, 9rem);
    font-weight: 800;
    color: var(--bg-deep);
    line-height: 1;
    margin: 0;
    letter-spacing: -0.05em;
}
.error-title { font-size: 1.8rem; margin: 0.2em 0 0.4em; }
.error-body { color: var(--ink-soft); margin-bottom: 2rem; }
.error-links { list-style: none; padding: 0; margin: 0; display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
.error-links a { font-weight: 600; }

/* ====================================================================
   Mobile
   ==================================================================== */

@media (max-width: 680px) {
    body { font-size: 16px; }
    .nav-bar { padding: 0 1rem; }
    .nav-links a { padding: 0.3em 0.45em; font-size: 0.85rem; }
    .hero { padding: 2.5rem 1rem 0; }
    .home-sections { padding: 2rem 1rem 4rem; }
    .site-main { padding: 2.5rem 1rem 4rem; }
    .book-shelf { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); }
    .app-grid { grid-template-columns: 1fr; }
}