.lsn-player-body{display:flex;flex-direction:column;gap:8px;min-width:0}.lsn-frame{position:relative;width:100%;aspect-ratio:16 / 9;background:var(--bg);border:1px solid var(--border);border-radius:var(--r);overflow:hidden}.lsn-frame iframe{position:absolute;inset:0;width:100%;height:100%;border:0}.lsn-frame-tools{position:absolute;top:10px;right:10px;z-index:1;display:flex;gap:6px}.lsn-full-btn{display:inline-flex;align-items:center;justify-content:center;width:34px;height:34px;padding:0;cursor:pointer;color:var(--text);background:var(--surface);border:1px solid var(--border);border-radius:var(--r);box-shadow:var(--shadow-sm);opacity:.85;transition:opacity .15s,border-color .15s}.lsn-full-btn:hover{opacity:1;border-color:var(--ebf-accent)}.lsn-full-btn:focus-visible{outline:2px solid var(--ebf-accent);outline-offset:1px;opacity:1}.lsn-frame:fullscreen{aspect-ratio:auto;border:0;border-radius:0;background:var(--bg);display:flex;align-items:center;justify-content:center}.lsn-frame:-webkit-full-screen{aspect-ratio:auto;border:0;border-radius:0;background:var(--bg);display:flex;align-items:center;justify-content:center}.lsn-frame:fullscreen iframe{position:static;inset:auto;width:min(100vw,calc(100vh * 16 / 9));height:auto;aspect-ratio:16 / 9}.lsn-frame:-webkit-full-screen iframe{position:static;inset:auto;width:min(100vw,calc(100vh * 16 / 9));height:auto;aspect-ratio:16 / 9}.lsn-player-title{font-size:15px;font-weight:600;color:var(--text)}.lsn-player-meta{display:flex;flex-wrap:wrap;align-items:center;gap:14px;font-size:12.5px;color:var(--text-sec)}.lsn-player-meta a{display:inline-flex;align-items:center;gap:4px;color:var(--ebf-accent)}.lsn-nav{display:flex;justify-content:space-between;gap:8px;flex-wrap:wrap}.lsn-nav button{display:inline-flex;align-items:center;gap:4px}.lsn-frame-empty{display:grid;place-items:center;color:var(--text-sec);font-size:14px}.spc-lessons{--spc-ink: var(--text);--spc-body: var(--text-sec);--spc-muted: var(--text-muted);--spc-line: var(--border);--spc-row: var(--bg);--spc-surface: var(--surface);--spc-accent: var(--ebf-accent);--spc-on: var(--text);--spc-on-ink: var(--surface);background:var(--spc-surface);border:1px solid var(--spc-line);color:var(--spc-ink);min-width:0}.spc-lessons-head{display:flex;align-items:center;justify-content:space-between;padding:20px 16px;min-height:80px;box-sizing:border-box}.spc-lessons-title{margin:0;font-size:20px;font-weight:600;line-height:30px}.spc-ring{position:relative;width:40px;height:40px;flex:none}.spc-ring svg{display:block}.spc-ring-track{fill:var(--spc-surface);stroke:var(--spc-line);stroke-width:1}.spc-ring-fill{fill:none;stroke:var(--spc-accent);stroke-width:2;stroke-linecap:round}.spc-ring-text{position:absolute;inset:0;display:grid;place-items:center;font-size:10px;font-weight:600;color:var(--spc-accent)}.spc-sections{list-style:none;margin:0;padding:0}.spc-section{border-top:1px solid var(--spc-line)}.spc-section-row{display:flex;align-items:center;gap:8px;padding:12px 16px;min-height:64px;box-sizing:border-box;background:var(--spc-row)}.spc-section.is-open .spc-section-row{border-bottom:1px solid var(--spc-line)}.spc-section-main{flex:1;min-width:0;display:flex;flex-direction:column;gap:0;background:none;border:0;padding:0;margin:0;text-align:left;color:inherit;font:inherit;cursor:pointer}.spc-section-main:disabled{cursor:default}.spc-section-main:focus-visible{outline:2px solid var(--spc-accent);outline-offset:2px;border-radius:4px}.spc-meta{display:inline-flex;align-items:center;gap:6px;font-size:10px;font-weight:600;line-height:16px;letter-spacing:.02em;text-transform:uppercase;color:var(--spc-muted)}.spc-meta-bar{width:1px;height:8px;background:var(--spc-line)}.spc-section-title{display:flex;align-items:center;gap:8px;min-width:0;font-size:14px;font-weight:600;line-height:24px;color:var(--spc-ink)}.spc-ellipsis{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;min-width:0}.spc-pdf{flex:none;display:grid;place-items:center;width:44px;height:44px;color:var(--spc-accent);border-radius:50%}.spc-pdf:focus-visible{outline:2px solid var(--spc-accent);outline-offset:0}.spc-lock{flex:none;display:grid;place-items:center;width:44px;height:44px;border-radius:50%;box-sizing:border-box;border:1px solid var(--spc-ink);background:transparent;color:var(--spc-ink);padding:0;font:inherit}.spc-lock.is-on{background:var(--spc-on);border-color:var(--spc-on);color:var(--spc-on-ink)}.spc-lock:not(.is-actionable){opacity:.45}.spc-lock.is-actionable{cursor:pointer}.spc-lock.is-actionable:hover:not(:disabled){box-shadow:0 0 0 3px var(--spc-line)}.spc-lock:focus-visible{outline:2px solid var(--spc-accent);outline-offset:2px}.spc-lock:disabled{cursor:progress}.spc-spin{width:16px;height:16px;border-radius:50%;border:2px solid currentColor;border-right-color:transparent;animation:spc-spin .8s linear infinite}@keyframes spc-spin{to{transform:rotate(360deg)}}@media(prefers-reduced-motion:reduce){.spc-spin{animation:none}}.spc-done{flex:none;display:grid;place-items:center;width:16px;height:16px;border-radius:50%;box-sizing:border-box;border:1.5px solid var(--spc-ink);color:var(--spc-on-ink)}.spc-done.is-done{background:var(--spc-accent);border-color:var(--spc-accent)}.spc-lesson-list{list-style:none;margin:0;padding:0 0 0 16px;background:var(--spc-surface)}.spc-lesson{padding:12px 16px 12px 0;border-bottom:1px solid var(--spc-line)}.spc-lesson:last-child{border-bottom:0}.spc-lesson-row{display:flex;align-items:center;gap:8px;min-width:0}.spc-lesson-title{flex:1;min-width:0;font-size:12px;font-weight:600;line-height:16px;color:var(--spc-ink)}.spc-lesson-slides{flex:none;gap:4px}.spc-lesson-desc{margin:8px 0 0;font-size:12px;line-height:16px;color:var(--spc-body)}.spc-tick{flex:none;display:grid;place-items:center;width:44px;height:44px;margin:-14px;background:none;border:0;padding:0;border-radius:50%;cursor:pointer;color:inherit}.spc-tick .spc-done{border-color:var(--spc-accent);box-shadow:0 0 0 3px var(--spc-row)}.spc-tick:hover:not(:disabled) .spc-done{box-shadow:0 0 0 3px var(--spc-line)}.spc-tick:focus-visible{outline:2px solid var(--spc-accent);outline-offset:-8px}.spc-tick:disabled{cursor:progress}.spc-spin-sm{width:10px;height:10px;border-width:1.5px;color:var(--spc-accent)}.spc-lesson-open{flex:1;min-width:0;display:flex;align-items:center;gap:8px;min-height:44px;margin:-14px 0;background:none;border:0;padding:0 4px;border-radius:4px;text-align:left;font:inherit;color:inherit;cursor:pointer}.spc-lesson-open:hover .spc-lesson-title{color:var(--spc-accent);text-decoration:underline}.spc-lesson-open:focus-visible{outline:2px solid var(--spc-accent);outline-offset:-2px}.spc-lesson.is-open{box-shadow:inset 3px 0 0 var(--spc-accent)}.spc-lesson.is-open .spc-lesson-title{color:var(--spc-accent)}