.arq-player-bar .arq-player-quality{width:76px;max-width:76px;font-variant-numeric:tabular-nums}
.arq-player-track>span.arq-player-chapter-marker{inset:0 auto 0 auto;width:3px;border-radius:0;background:#080a0d;will-change:auto}
.lesson-chapters{display:grid;gap:6px;margin:16px 0 0;padding:12px 0 0;border-top:1px solid var(--line,#414145)}
.lesson-chapter-button{display:flex;align-items:baseline;gap:12px;width:100%;min-height:44px;padding:10px 12px;text-align:left;font:inherit;font-size:13px;line-height:1.5;border:1px solid transparent;border-radius:6px;background:var(--surface-2,#222224);color:var(--ink,#fff);cursor:pointer}
.lesson-chapter-button>span{min-width:0;overflow-wrap:anywhere}
.lesson-chapter-time{flex:none;font-variant-numeric:tabular-nums;font-weight:700;color:var(--accent,#26bbff)}
.lesson-chapter-button:hover{border-color:var(--accent,#26bbff)}
.lesson-chapter-button:focus-visible{outline:2px solid var(--accent,#26bbff);outline-offset:2px}
@media(max-width:560px){.arq-player-bar:has(.arq-player-quality){flex-wrap:wrap;row-gap:2px}.arq-player-bar .arq-player-quality{width:66px;max-width:66px;font-size:11px}}

.lesson-discussion{margin-top:24px;border-top:1px solid var(--line,#414145);color:var(--ink,#fff)}
.discussion-toggle{display:flex;align-items:center;justify-content:space-between;gap:12px;width:100%;min-height:48px;padding:12px 0;border:0;background:transparent;color:inherit;font:inherit;font-weight:650;text-align:left;cursor:pointer}
.discussion-thread{display:grid;gap:16px;padding:8px 0 16px;min-width:0}
.lesson-discussion button,.lesson-warning-gate button{min-height:44px;font:inherit;font-size:13px;cursor:pointer}
.lesson-discussion button:disabled,.lesson-warning-gate button:disabled{cursor:default;opacity:.6}
.lesson-discussion :focus-visible,.lesson-warning-gate :focus-visible{outline:2px solid var(--accent,#26bbff);outline-offset:3px}
.lesson-discussion-messages{list-style:none;margin:0;padding:0;display:grid;gap:16px}
.discussion-message{min-width:0;padding-bottom:16px;border-bottom:1px solid var(--line,#414145)}
.discussion-reply{margin-left:12px;padding-left:16px;border-left:2px solid var(--line,#414145)}
.discussion-message header{display:flex;align-items:baseline;flex-wrap:wrap;gap:6px 12px;font-size:13px}
.discussion-message header time{margin-left:auto;font-size:11px;color:var(--muted,#d0d0d3)}
.discussion-teacher{font-size:11px;color:var(--accent,#26bbff)}
.discussion-message-body,.lesson-warning-text{white-space:pre-wrap;overflow-wrap:anywhere;font-size:14px;line-height:1.65;margin:10px 0}
.discussion-message-actions{display:flex;gap:16px;flex-wrap:wrap}
.discussion-message-actions button,.discussion-private>button,.discussion-reply-target button,.warning-back{padding:4px 0;border:0;background:transparent;color:var(--accent,#26bbff)}
.discussion-empty,.discussion-removed{color:var(--muted,#d0d0d3);font-size:14px;line-height:1.6}
.discussion-form,.discussion-moderation-form{display:grid;gap:8px;margin:0}
.lesson-discussion textarea{box-sizing:border-box;display:block;width:100%;min-height:100px;resize:vertical;padding:12px;border:1px solid var(--line,#68686d);border-radius:6px;background:var(--surface-2,#222224);color:var(--ink,#fff);font:inherit;font-size:14px;line-height:1.5}
.discussion-form label,.discussion-moderation-form label{font-size:13px;font-weight:650}
.discussion-form-actions,.discussion-reply-target{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:8px 16px}
.discussion-form-actions small{color:var(--muted,#d0d0d3);font-size:12px}
.discussion-form-actions button,.lesson-warning-gate form>button{padding:10px 16px;border:1px solid transparent;border-radius:6px;background:var(--accent,#26bbff);color:var(--accent-ink,#071c28);font-weight:650}
.discussion-reply-target{font-size:12px;color:var(--muted,#d0d0d3)}
.discussion-moderation-form,.discussion-private{padding-top:16px;border-top:1px solid var(--line,#414145)}
.discussion-moderation-form h3{font-size:16px;margin:0}
.discussion-private article{padding:12px 0;border-bottom:1px solid var(--line,#414145);font-size:13px}
.lesson-warning-gate{box-sizing:border-box;max-width:760px;margin:24px auto;padding:24px;border:1px solid var(--line,#414145);border-radius:12px;background:var(--surface,#1c1c1e);color:var(--ink,#fff)}
.lesson-warning-gate h2{font-size:22px;line-height:1.3;margin:0 0 16px}
.lesson-warning-gate:modal{position:fixed;inset:0;width:min(760px,calc(100vw - 32px));max-height:calc(100dvh - 32px);overflow:auto;margin:auto}
.lesson-warning-gate::backdrop{background:#0008}
.lesson-adult-badge{display:inline-flex;align-items:center;justify-content:center;min-height:24px;padding:2px 7px;border:1px solid #ef8383;border-radius:4px;background:#6e1717;color:#fff;font-size:11px;font-weight:750;line-height:1.3;white-space:nowrap}
.lesson-warning-gate form{display:grid;gap:16px;margin-top:24px}
.lesson-warning-gate label{display:flex;align-items:flex-start;gap:12px;font-size:14px;line-height:1.6;cursor:pointer}
.lesson-warning-gate input[type=checkbox]{flex:none;width:18px;height:18px;margin:2px 0 0;accent-color:var(--accent,#26bbff)}
.warning-back{margin-top:12px}
[data-theme="dark"] .lesson-discussion,[data-theme="dark"] .lesson-warning-gate{--accent:#26bbff;--accent-ink:#071c28;--ink:#fff;--muted:#d0d0d3;--surface:#1c1c1e;--surface-2:#222224;--line:#414145}
@media(max-width:600px){.lesson-warning-gate{padding:16px;margin:16px 0}.lesson-warning-gate h2{font-size:20px}.lesson-discussion textarea{font-size:16px}.discussion-message header time{margin-left:0}.discussion-reply{margin-left:0;padding-left:12px}}

/* Single-quality players retain room for captions and speed on small screens. */
@media(max-width:560px){.arq-player-bar{flex-wrap:wrap;row-gap:2px}}