/**
 * Tutorial Watch/Read mode — tabs, theme tokens, long-form article reader.
 *
 * Layers onto the existing .tv-app theater layout. The host view declares
 * dark-theme tokens inline; this stylesheet *overrides them by default* now
 * that light is the primary surface (text-first reader pivot, 2026-05-14).
 *
 * - `.tv-app` baseline → light theme.
 * - `.tv-app[data-theme="dark"]` → restores the dark palette for users who
 *   choose it from the theme toggle. The JS always sets data-theme explicitly
 *   (light or dark) so this never relies on the absence of the attribute.
 *
 * Mode is set via [data-mode="read"|"watch"] on .tv-body. The host wraps the
 * existing .tv-player-pane + .tv-library inside .tv-body so both modes sit
 * side-by-side and toggle without a remount.
 */

/* ───── Default = light theme ─────────────────────────────────────────────
   Specificity-bumped (.tv-app + attr) so we beat the inline dark tokens in
   the view files. The host always sets [data-theme="light"] on first paint. */
.tv-app[data-theme="light"],
.tv-app:not([data-theme]) {
    /* Warm paper palette — comfortable for long reading, holds the accent. */
    --bg-0: oklch(0.992 0.004 85);   /* page */
    --bg-1: oklch(0.975 0.006 85);   /* card surface */
    --bg-2: oklch(0.945 0.008 85);   /* hovered */
    --bg-3: oklch(0.905 0.010 85);   /* deepest fill */
    --line-soft: oklch(0.50 0.012 80 / 0.14);
    --line: oklch(0.50 0.012 80 / 0.22);
    --ink-0: oklch(0.18 0.010 60);   /* headings, primary */
    --ink-1: oklch(0.28 0.012 60);   /* body */
    --ink-2: oklch(0.44 0.012 60);   /* secondary */
    --ink-3: oklch(0.58 0.010 60);   /* tertiary, mono */
    --ink-4: oklch(0.72 0.008 60);   /* faded */
}

/* Dark theme — opt-in. */
.tv-app[data-theme="dark"] {
    --bg-0: oklch(0.14 0.008 60);
    --bg-1: oklch(0.17 0.008 60);
    --bg-2: oklch(0.21 0.009 60);
    --bg-3: oklch(0.26 0.010 60);
    --line-soft: oklch(0.32 0.010 60 / 0.25);
    --line: oklch(0.32 0.010 60 / 0.5);
    --ink-0: oklch(0.98 0.005 80);
    --ink-1: oklch(0.88 0.008 80);
    --ink-2: oklch(0.70 0.010 80);
    --ink-3: oklch(0.52 0.010 80);
    --ink-4: oklch(0.40 0.010 80);
}

/* When no articles exist, collapse the reserved first row so .tv-body still
   claims the full viewport. */
.tv-app:not(:has(.tv-tabs)) {
    grid-template-rows: 1fr;
}

/* ───── Tab bar (top of canvas, full width) ───── */
.tv-app .tv-tabs {
    grid-row: 1;
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 4px;
    padding: 12px 20px;
    background: var(--bg-0);
    border-bottom: 1px solid var(--line-soft);
    position: relative;
    z-index: 12;
}
.tv-app[data-theme="dark"] .tv-tabs {
    background: linear-gradient(180deg, color-mix(in srgb, var(--bg-0) 96%, transparent) 0%, color-mix(in srgb, var(--bg-0) 88%, transparent) 100%);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.tv-app .tv-tabs-group {
    grid-column: 2;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px;
    background: var(--bg-2);
    border-radius: 999px;
    border: 1px solid var(--line-soft);
}
.tv-app[data-theme="light"] .tv-tabs-group,
.tv-app:not([data-theme]) .tv-tabs-group {
    background: oklch(0.93 0.008 85);
    box-shadow: inset 0 1px 2px oklch(0.50 0.012 80 / 0.06);
}

.tv-app .tv-tab {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 9px 20px;
    border-radius: 999px;
    background: transparent;
    border: 1px solid transparent;
    color: var(--ink-2);
    font-family: var(--ff-sans);
    font-size: 13.5px;
    font-weight: 500;
    letter-spacing: -0.005em;
    cursor: pointer;
    transition: background 0.18s ease, color 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
    position: relative;
}
.tv-app .tv-tab svg {
    width: 14px;
    height: 14px;
    stroke-width: 1.8;
}
.tv-app .tv-tab:hover {
    color: var(--ink-0);
    background: color-mix(in srgb, var(--ink-0) 5%, transparent);
}

.tv-app .tv-tab[aria-selected="true"] {
    color: var(--ink-0);
    background: var(--bg-0);
    font-weight: 600;
    box-shadow: 0 1px 2px oklch(0.50 0.012 80 / 0.06), 0 6px 18px oklch(0.50 0.012 80 / 0.08);
}
.tv-app[data-theme="dark"] .tv-tab[aria-selected="true"] {
    background: var(--ink-0);
    color: var(--bg-0);
    box-shadow: 0 6px 18px color-mix(in srgb, var(--bg-0) 25%, transparent);
}
.tv-app .tv-tab[aria-selected="true"]:hover { background: var(--bg-0); }
.tv-app[data-theme="dark"] .tv-tab[aria-selected="true"]:hover { background: var(--ink-0); }

.tv-app .tv-tab-count {
    font-family: var(--ff-mono);
    font-size: 10.5px;
    letter-spacing: 0.04em;
    color: var(--ink-3);
    padding: 2px 8px;
    border-radius: 999px;
    background: color-mix(in srgb, var(--ink-0) 8%, transparent);
}
.tv-app .tv-tab[aria-selected="true"] .tv-tab-count {
    background: color-mix(in srgb, var(--tv-accent) 18%, transparent);
    color: var(--tv-accent);
}
.tv-app[data-theme="dark"] .tv-tab[aria-selected="true"] .tv-tab-count {
    background: color-mix(in srgb, var(--bg-0) 22%, transparent);
    color: color-mix(in srgb, var(--bg-0) 78%, transparent);
}

/* ───── Theme toggle (sun/moon button at far right of tabs row) ───── */
.tv-app .tv-tab-theme {
    grid-column: 3;
    justify-self: end;
    width: 38px;
    height: 38px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 999px;
    background: transparent;
    border: 1px solid var(--line-soft);
    color: var(--ink-2);
    cursor: pointer;
    transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}
.tv-app .tv-tab-theme:hover {
    background: color-mix(in srgb, var(--ink-0) 5%, transparent);
    color: var(--ink-0);
    border-color: color-mix(in srgb, var(--ink-2) 35%, transparent);
}
.tv-app .tv-tab-theme svg { width: 16px; height: 16px; }
/* Sun shows in light mode, moon in dark mode — only one at a time. */
.tv-app .tv-tab-theme .tv-theme-icon-sun { display: none; }
.tv-app .tv-tab-theme .tv-theme-icon-moon { display: block; }
.tv-app[data-theme="light"] .tv-tab-theme .tv-theme-icon-sun,
.tv-app:not([data-theme]) .tv-tab-theme .tv-theme-icon-sun { display: block; }
.tv-app[data-theme="light"] .tv-tab-theme .tv-theme-icon-moon,
.tv-app:not([data-theme]) .tv-tab-theme .tv-theme-icon-moon { display: none; }

/* ───── Layout host — wraps player+library AND the read pane ───── */
.tv-app .tv-body {
    grid-row: 2;
    display: grid;
    grid-template-columns: 1fr 360px;
    min-height: 0;
    min-width: 0;
    overflow: hidden;
}
.tv-app .tv-body[data-mode="watch"] .tv-read { display: none; }
.tv-app .tv-body[data-mode="read"] {
    grid-template-columns: 1fr;
}
.tv-app .tv-body[data-mode="read"] .tv-player-pane,
.tv-app .tv-body[data-mode="read"] .tv-library { display: none; }

/* ───── Read pane: sticky TOC + long-form prose column ───── */
.tv-app .tv-read {
    display: grid;
    grid-template-columns: 260px 1fr;
    min-height: 0;
    min-width: 0;
    overflow: hidden;
    background: var(--bg-0);
}
.tv-app[data-theme="dark"] .tv-read {
    background:
        radial-gradient(900px 600px at 80% 0%, color-mix(in srgb, var(--tv-accent) 8%, transparent), transparent 70%),
        var(--bg-0);
}

/* ───── TOC — pinned left, scrolls independently ───── */
.tv-app .tv-read-toc {
    border-right: 1px solid var(--line-soft);
    padding: 36px 0 28px 0;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--bg-3) transparent;
    background: var(--bg-1);
}
.tv-app .tv-read-toc::-webkit-scrollbar { width: 6px; }
.tv-app .tv-read-toc::-webkit-scrollbar-thumb { background: var(--bg-3); border-radius: 3px; }
.tv-app .tv-toc-eyebrow {
    font-family: var(--ff-mono);
    font-size: 10px;
    letter-spacing: 0.22em;
    color: var(--ink-3);
    text-transform: uppercase;
    padding: 0 28px 14px;
}
.tv-app .tv-toc-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
}
.tv-app .tv-toc-item { display: block; }
.tv-app .tv-toc-link {
    display: grid;
    grid-template-columns: 28px 1fr;
    gap: 12px;
    align-items: flex-start;
    padding: 11px 28px;
    color: var(--ink-2);
    text-decoration: none;
    font-size: 13.5px;
    line-height: 1.4;
    border-left: 2px solid transparent;
    transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}
.tv-app .tv-toc-link:hover {
    background: color-mix(in srgb, var(--ink-0) 4%, transparent);
    color: var(--ink-0);
}
.tv-app .tv-toc-link.active {
    color: var(--ink-0);
    border-left-color: var(--tv-accent);
    background: color-mix(in srgb, var(--tv-accent) 6%, transparent);
}
.tv-app .tv-toc-num {
    font-family: var(--ff-mono);
    font-size: 10.5px;
    color: var(--ink-3);
    padding-top: 3px;
    letter-spacing: 0.04em;
}
.tv-app .tv-toc-link.active .tv-toc-num { color: var(--tv-accent); font-weight: 500; }
.tv-app .tv-toc-title {
    font-weight: 500;
    letter-spacing: -0.005em;
}
.tv-app .tv-toc-coming {
    display: inline-block;
    margin-top: 2px;
    font-family: var(--ff-mono);
    font-size: 9px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--ink-4);
}

/* ───── Prose column ───── */
.tv-app .tv-read-prose {
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--bg-3) transparent;
    scroll-behavior: smooth;
    background: var(--bg-0);
}
.tv-app .tv-read-prose::-webkit-scrollbar { width: 8px; }
.tv-app .tv-read-prose::-webkit-scrollbar-thumb { background: var(--bg-3); border-radius: 4px; }
.tv-app .tv-read-prose-inner {
    max-width: 720px;
    margin: 0 auto;
    padding: 64px 48px 128px;
}

.tv-app .tv-read-hero {
    margin-bottom: 64px;
    padding-bottom: 36px;
    border-bottom: 1px solid var(--line-soft);
}
.tv-app .tv-read-hero-eyebrow {
    font-family: var(--ff-mono);
    font-size: 10.5px;
    letter-spacing: 0.22em;
    color: var(--ink-3);
    text-transform: uppercase;
    margin-bottom: 16px;
}
.tv-app .tv-read-hero-title {
    font-family: var(--ff-display);
    font-size: 48px;
    font-weight: 500;
    line-height: 1.04;
    letter-spacing: -0.028em;
    color: var(--ink-0);
    margin: 0 0 16px;
    text-wrap: balance;
}
.tv-app .tv-read-hero-sub {
    font-size: 17px;
    line-height: 1.55;
    color: var(--ink-2);
    margin: 0;
    text-wrap: pretty;
}

/* ───── A single lesson card ───── */
.tv-app .tv-lesson {
    padding-top: 28px;
    padding-bottom: 64px;
    border-bottom: 1px solid var(--line-soft);
    scroll-margin-top: 24px;
}
.tv-app .tv-lesson:last-child {
    border-bottom: 0;
    padding-bottom: 0;
}
.tv-app .tv-lesson-head {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}
.tv-app .tv-lesson-meta {
    display: flex;
    align-items: baseline;
    gap: 10px;
    font-family: var(--ff-mono);
    font-size: 11px;
    color: var(--ink-3);
    letter-spacing: 0.06em;
}
.tv-app .tv-lesson-num { color: var(--tv-accent); font-weight: 500; }
.tv-app .tv-lesson-dot { color: var(--ink-4); }
.tv-app .tv-lesson-watch {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 14px 7px 12px;
    border-radius: 999px;
    background: transparent;
    border: 1px solid color-mix(in srgb, var(--tv-accent) 32%, transparent);
    color: var(--tv-accent);
    font-family: var(--ff-sans);
    font-size: 12.5px;
    font-weight: 500;
    letter-spacing: -0.005em;
    cursor: pointer;
    transition: background 0.15s ease, border-color 0.15s ease, transform 0.15s ease;
}
.tv-app .tv-lesson-watch:hover {
    background: color-mix(in srgb, var(--tv-accent) 10%, transparent);
    border-color: color-mix(in srgb, var(--tv-accent) 55%, transparent);
}
.tv-app .tv-lesson-watch svg {
    width: 12px;
    height: 12px;
    fill: currentColor;
}
.tv-app .tv-lesson-title {
    font-family: var(--ff-display);
    font-size: 32px;
    font-weight: 500;
    letter-spacing: -0.022em;
    line-height: 1.12;
    color: var(--ink-0);
    margin: 0 0 16px;
    text-wrap: balance;
}
.tv-app .tv-lesson-desc {
    font-size: 16px;
    line-height: 1.6;
    color: var(--ink-2);
    margin: 0 0 28px;
    text-wrap: pretty;
    font-style: italic;
}

/* ───── Markdown-rendered body ───── */
.tv-app .tv-lesson-body {
    font-size: 16.5px;
    line-height: 1.72;
    color: var(--ink-1);
}
.tv-app .tv-lesson-body > * + * { margin-top: 1.2em; }
.tv-app .tv-lesson-body h2 {
    font-family: var(--ff-display);
    font-size: 26px;
    font-weight: 500;
    letter-spacing: -0.018em;
    color: var(--ink-0);
    margin-top: 2em;
    margin-bottom: 0.5em;
    line-height: 1.2;
}
.tv-app .tv-lesson-body h3 {
    font-family: var(--ff-sans);
    font-size: 18px;
    font-weight: 600;
    letter-spacing: -0.005em;
    color: var(--ink-0);
    margin-top: 1.8em;
    margin-bottom: 0.4em;
}
.tv-app .tv-lesson-body h4 {
    font-family: var(--ff-mono);
    font-size: 11px;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--ink-3);
    margin-top: 1.8em;
    margin-bottom: 0.4em;
}
.tv-app .tv-lesson-body p {
    margin: 0;
    text-wrap: pretty;
}
.tv-app .tv-lesson-body ul,
.tv-app .tv-lesson-body ol {
    margin: 0;
    padding-left: 1.5em;
}
.tv-app .tv-lesson-body li {
    margin: 0.5em 0;
}
.tv-app .tv-lesson-body li::marker { color: var(--ink-3); }
.tv-app .tv-lesson-body a {
    color: var(--tv-accent);
    text-decoration: none;
    border-bottom: 1px solid color-mix(in srgb, var(--tv-accent) 40%, transparent);
    transition: border-color 0.15s;
}
.tv-app .tv-lesson-body a:hover { border-bottom-color: var(--tv-accent); }
.tv-app .tv-lesson-body strong { color: var(--ink-0); font-weight: 600; }
.tv-app .tv-lesson-body em { color: var(--ink-1); }
.tv-app .tv-lesson-body code {
    font-family: var(--ff-mono);
    font-size: 0.88em;
    background: var(--bg-2);
    color: var(--ink-0);
    padding: 2px 7px;
    border-radius: 5px;
    border: 1px solid var(--line-soft);
}
.tv-app .tv-lesson-body pre {
    background: var(--bg-1);
    border: 1px solid var(--line-soft);
    border-radius: 12px;
    padding: 18px 20px;
    overflow-x: auto;
    margin: 1.6em 0;
}
.tv-app .tv-lesson-body pre code {
    background: transparent;
    border: 0;
    padding: 0;
    font-size: 13.5px;
    line-height: 1.6;
    color: var(--ink-1);
}
.tv-app .tv-lesson-body blockquote {
    margin: 1.6em 0;
    padding: 14px 22px;
    border-left: 3px solid var(--tv-accent);
    background: color-mix(in srgb, var(--tv-accent) 7%, transparent);
    border-radius: 0 10px 10px 0;
    color: var(--ink-1);
}
.tv-app .tv-lesson-body blockquote p { margin: 0; }
.tv-app .tv-lesson-body blockquote p + p { margin-top: 0.6em; }
.tv-app .tv-lesson-body figure {
    margin: 1.6em -8px;
}
.tv-app .tv-lesson-body img {
    display: block;
    max-width: 100%;
    height: auto;
    border-radius: 14px;
    border: 1px solid var(--line-soft);
    box-shadow: 0 8px 24px oklch(0.50 0.012 80 / 0.08);
}
.tv-app[data-theme="dark"] .tv-lesson-body img {
    box-shadow: 0 8px 24px rgba(0,0,0,0.3);
}
.tv-app .tv-lesson-body hr {
    border: 0;
    border-top: 1px solid var(--line-soft);
    margin: 2.4em 0;
}

/* ───── "Coming soon" placeholder when a video has no article ───── */
.tv-app .tv-lesson-pending {
    padding: 22px 26px;
    background: var(--bg-1);
    border: 1px dashed var(--line);
    border-radius: 14px;
    color: var(--ink-3);
    font-size: 14.5px;
    line-height: 1.6;
}
.tv-app .tv-lesson-pending strong { color: var(--ink-1); font-weight: 600; }

/* ───── Empty state — no articles anywhere yet ───── */
.tv-app .tv-read-empty {
    display: grid;
    place-items: center;
    padding: 80px 32px;
    text-align: center;
    color: var(--ink-2);
    max-width: 520px;
    margin: 0 auto;
}
.tv-app .tv-read-empty svg {
    width: 56px;
    height: 56px;
    color: var(--ink-3);
    margin-bottom: 18px;
}
.tv-app .tv-read-empty h3 {
    font-family: var(--ff-display);
    font-size: 24px;
    font-weight: 500;
    color: var(--ink-0);
    margin: 0 0 8px;
    letter-spacing: -0.015em;
}
.tv-app .tv-read-empty p { margin: 0; line-height: 1.55; }

/* ───── Responsive ───── */
@media (max-width: 1100px) {
    .tv-app .tv-read { grid-template-columns: 220px 1fr; }
    .tv-app .tv-read-prose-inner { padding: 56px 40px 96px; }
}
@media (max-width: 920px) {
    .tv-app .tv-body { grid-template-rows: auto auto auto; }
    .tv-app .tv-body[data-mode="read"] {
        grid-template-columns: 1fr;
    }
    .tv-app .tv-read { grid-template-columns: 1fr; grid-template-rows: auto 1fr; }
    .tv-app .tv-read-toc {
        border-right: 0;
        border-bottom: 1px solid var(--line-soft);
        padding: 18px 0;
        max-height: 200px;
    }
    .tv-app .tv-read-prose-inner { padding: 36px 22px 80px; }
    .tv-app .tv-read-hero-title { font-size: 34px; }
    .tv-app .tv-lesson-title { font-size: 24px; }
    .tv-app .tv-lesson-body { font-size: 15.5px; }
}