/*
 * learn-player.css — learner-facing course views: outline (.sat-course), lesson
 * player (.sat-learn), locked page (.sat-locked) and the completion celebration
 * overlay (.sat-celebrate).
 *
 * Extracted from the per-view inline <style> blocks (R1.10) onto the shared design
 * system: radii via --radius-* tokens, colours via theme vars (no raw hex), and the
 * global .sat-btn system (button.css) instead of the old page-local .sat-cbtn /
 * .sat-btn shadows — which restores :focus-visible rings on every learner CTA for
 * free. The two pages' .sat-llist rules are scoped under their page root so they
 * cannot collide when this one stylesheet loads on both.
 */

/* ── Shared a11y utilities ─────────────────────────────────────────── */
.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;
}
.sat-skip {
    position: absolute; left: 0.5rem; top: -3rem; z-index: 1001;
    padding: 0.5rem 0.9rem; border-radius: var(--radius-md);
    background: var(--brand-primary); color: var(--text-inverse);
    text-decoration: none; transition: top 0.15s ease;
}
.sat-skip:focus { top: 0.5rem; }

/* ── Lesson player (root .sat-learn) ───────────────────────────────── */
.sat-learn { max-width: 1080px; margin: 1.5rem auto; padding: 0 1rem; color: var(--text-primary); display: grid; grid-template-columns: 280px 1fr; gap: 1.75rem; }
.sat-learn__nav { border-right: 1px solid var(--border-secondary); padding-right: 1rem; }
.sat-learn__crumb { font-size: 0.85rem; color: var(--text-tertiary); margin-bottom: 0.75rem; }
.sat-learn__crumb a { color: var(--text-tertiary); }
.sat-sec-title { font-size: 0.78rem; text-transform: uppercase; color: var(--text-tertiary); margin: 1rem 0 0.4rem; font-weight: 600; }
.sat-learn__main h1 { font-size: 1.6rem; font-weight: 600; margin: 0 0 0.25rem; }
.sat-learn__type { font-size: 0.78rem; text-transform: uppercase; color: var(--text-tertiary); margin-bottom: 1.25rem; }
.sat-body { line-height: 1.7; }
.sat-body img { max-width: 100%; height: auto; }
.sat-placeholder { padding: 2rem; text-align: center; border: 1px dashed var(--border-primary); border-radius: var(--radius-lg); color: var(--text-tertiary); }

/* lesson sidebar list (scoped under .sat-learn) */
.sat-learn .sat-llist { list-style: none; margin: 0; padding: 0; }
.sat-learn .sat-llist a, .sat-learn .sat-llist span { display: block; padding: 0.4rem 0.5rem; border-radius: var(--radius-sm); text-decoration: none; color: var(--text-secondary); font-size: 0.92rem; }
.sat-learn .sat-llist a:hover { background: var(--bg-secondary); }
.sat-learn .sat-llist a:focus-visible { outline: 2px solid var(--brand-primary); outline-offset: 2px; }
.sat-learn .sat-llist .is-current { background: var(--brand-primary-subtle); color: var(--brand-primary); font-weight: 600; }
.sat-learn .sat-llist .is-locked { color: var(--text-quaternary); cursor: not-allowed; }

/* player + completion CTA */
.sat-player { margin-bottom: 1.5rem; }
.sat-embed { position: relative; width: 100%; padding-top: 56.25%; border-radius: var(--radius-lg); overflow: hidden; background: var(--bg-tertiary); }
.sat-embed iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.sat-player__status { font-size: 0.85rem; color: var(--text-tertiary); margin: 0.6rem 0 0; }
.sat-player__status[data-player-error] { color: var(--error); font-weight: 500; }
.sat-complete { margin-top: 2rem; padding-top: 1.5rem; border-top: 1px solid var(--border-secondary); display: flex; align-items: center; gap: 0.75rem; flex-wrap: wrap; }
.sat-complete__msg { color: var(--error); font-size: 0.9rem; }
.sat-learn__next { margin-top: 2rem; }

/* ── Course outline (root .sat-course) ─────────────────────────────── */
.sat-course { max-width: 760px; margin: 2rem auto; padding: 0 1rem; color: var(--text-primary); }
.sat-course h1 { font-size: 1.8rem; font-weight: 600; margin: 0 0 0.5rem; }
.sat-course__desc { color: var(--text-secondary); line-height: 1.6; margin-bottom: 1rem; }
.sat-course__status { display: inline-block; font-size: 0.8rem; padding: 0.1rem 0.6rem; border-radius: var(--radius-pill); background: var(--bg-tertiary); color: var(--text-tertiary); margin-bottom: 1.5rem; }
.sat-sec { margin-bottom: 1.25rem; }
.sat-sec__t { font-weight: 600; margin-bottom: 0.4rem; }
.sat-course .sat-llist { list-style: none; margin: 0; padding: 0; }
.sat-course .sat-llist li { display: flex; align-items: center; justify-content: space-between; padding: 0.5rem 0.6rem; border-bottom: 1px solid var(--border-secondary); }
.sat-course .sat-llist a { text-decoration: none; color: var(--brand-primary); font-weight: 500; }
.sat-course .sat-llist a:focus-visible { outline: 2px solid var(--brand-primary); outline-offset: 2px; }
.sat-course .sat-llist .locked { color: var(--text-quaternary); }
.sat-tag { font-size: 0.72rem; text-transform: uppercase; color: var(--text-tertiary); border: 1px solid var(--border-secondary); border-radius: var(--radius-pill); padding: 0.05rem 0.5rem; }
.sat-tag--preview { color: var(--brand-primary); border-color: var(--brand-primary); }

/* ── Locked page (root .sat-locked) ────────────────────────────────── */
.sat-locked { max-width: 560px; margin: 4rem auto; padding: 2rem; text-align: center; color: var(--text-primary); }
.sat-locked__icon { font-size: 2.5rem; color: var(--text-tertiary); }
.sat-locked h1 { font-size: 1.4rem; font-weight: 600; margin: 0.75rem 0 0.5rem; }
.sat-locked p { color: var(--text-secondary); margin-bottom: 1.5rem; }

/* ── Completion celebration overlay (root .sat-celebrate) ──────────── */
.sat-celebrate { position: fixed; inset: 0; z-index: 1000; display: flex; align-items: center; justify-content: center; padding: 1rem; background: rgba(0, 0, 0, 0.5); }
.sat-celebrate[hidden] { display: none; }
.sat-celebrate__box { position: relative; width: 100%; max-width: 460px; padding: 2.5rem 2rem 2rem; text-align: center; background: var(--bg-primary); border: 1px solid var(--border-secondary); border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); }
.sat-celebrate__icon { font-size: 3rem; line-height: 1; color: var(--brand-primary); }
.sat-celebrate__title { font-size: 1.5rem; font-weight: 700; margin: 0.75rem 0 0.5rem; color: var(--text-primary); }
.sat-celebrate__body { color: var(--text-secondary); line-height: 1.6; margin: 0 0 1.5rem; }
.sat-celebrate__actions { display: flex; gap: 0.75rem; justify-content: center; flex-wrap: wrap; }
.sat-celebrate__close { position: absolute; top: 0.5rem; right: 0.5rem; padding: 0.35rem; line-height: 1; font-size: 1.25rem; cursor: pointer; background: transparent; border: 0; border-radius: var(--radius-sm); color: var(--text-tertiary); }
.sat-celebrate__close:hover { color: var(--text-primary); background: var(--bg-secondary); }
.sat-celebrate__close:focus-visible { outline: 2px solid var(--brand-primary); outline-offset: 2px; }

/* ── Responsive ────────────────────────────────────────────────────── */
@media (max-width: 760px) {
    .sat-learn { grid-template-columns: 1fr; }
    .sat-learn__nav { border-right: 0; border-bottom: 1px solid var(--border-secondary); padding: 0 0 1rem; }
}