:root {
  --bg: #f3f5f9;
  --surface: #ffffff;
  --surface-2: #eef2f8;
  --line: #dfe5ee;
  --text: #17202e;
  --muted: #5d6a7e;
  --brand: #1d5fd1;
  --brand-soft: #e5eefc;
  --accent: #e2462c;
  --ok: #1d9a5f;
  --ok-soft: #e3f5ec;
  --warn: #c97800;
  --warn-soft: #fdf1dc;
  --shadow: 0 1px 2px rgba(16, 24, 40, .06), 0 8px 24px rgba(16, 24, 40, .08);
  --radius: 14px;
  --stage-bg: #ffffff;
  font-family: "Noto Sans TC", "Microsoft JhengHei", "PingFang TC", system-ui, sans-serif;
  /* 一律使用淺色版，不跟著電腦的深色模式變暗 */
  color-scheme: light;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--bg); color: var(--text); line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; border: 0; background: none; }
svg { display: block; }
.ico { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

/* ---------- 共用按鈕 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 18px; border-radius: 999px; font-weight: 600; font-size: 15px;
  background: var(--surface-2); transition: transform .15s, background .15s, box-shadow .15s;
}
.btn:hover { transform: translateY(-1px); }
.btn.primary { background: var(--brand); color: #fff; box-shadow: 0 6px 18px rgba(29, 95, 209, .35); }
.btn.ghost { background: rgba(255, 255, 255, .14); color: #fff; backdrop-filter: blur(6px); }
.btn.small { padding: 6px 12px; font-size: 13px; }

/* ---------- 頂部列 ---------- */
.topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; gap: 16px;
  padding: 12px 24px; background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: blur(10px); border-bottom: 1px solid var(--line);
}
.topbar .back { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); font-size: 14px; }
.topbar .back:hover { color: var(--brand); }
.topbar .crumb { display: flex; flex-direction: column; min-width: 0; }
.topbar .crumb small { color: var(--muted); font-size: 12px; }
.topbar .crumb strong { font-size: 17px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.topbar .spacer { flex: 1; }

.seg { display: inline-flex; background: var(--surface-2); border-radius: 999px; padding: 4px; }
.seg button { display: inline-flex; align-items: center; gap: 6px; padding: 6px 14px; border-radius: 999px; font-size: 14px; color: var(--muted); }
.seg button.on { background: var(--surface); color: var(--brand); font-weight: 700; box-shadow: var(--shadow); }

/* ---------- 播放頁佈局 ---------- */
.layout { display: grid; grid-template-columns: minmax(0, 1fr) 340px; gap: 24px; max-width: 1480px; margin: 0 auto; padding: 24px; }
@media (max-width: 1080px) { .layout { grid-template-columns: 1fr; } }

.player { background: var(--stage-bg); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
.player:fullscreen { border-radius: 0; display: flex; flex-direction: column; justify-content: center; }
.player:fullscreen .stage { max-height: calc(100vh - 64px); margin: 0 auto; }
.stage { position: relative; width: 100%; aspect-ratio: var(--ar, 1364 / 724); background: #000; user-select: none; }
.stage video { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: fill; }
/* 匯出 mp4（tools/export.py）：只留影片畫面，填滿視窗 */
body.export { overflow: hidden; }
body.export .topbar, body.export .controls, body.export .keys, body.export .side { display: none; }
body.export .layout { display: block; max-width: none; padding: 0; }
body.export .player { border-radius: 0; box-shadow: none; }
body.export .screen { transition: none; }
.overlay { position: absolute; inset: 0; }

/* 遮蓋影片中過時的畫面元素（例如 IE 圖示），依原影片時間顯示 */
.covers { position: absolute; inset: 0; pointer-events: none; }
.covers span { position: absolute; display: none; background: #fff no-repeat center / 88% auto; }
.covers span.on { display: block; }
.covers span.edge { background-image: url("edge.svg"); }

/* 手冊截圖步驟：取代已過時的影片畫面 */
.slide {
  position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; padding: 18px 28px 58px;
  background: radial-gradient(ellipse at 50% 40%, #f4f7fc 0%, #dfe6f1 100%);
}
.slide[hidden] { display: none; }
.slide img { max-width: 100%; max-height: 100%; border-radius: 6px; box-shadow: 0 10px 40px rgba(16, 24, 40, .22); background: #fff; }
.slide img[hidden] { display: none; }
.slide-text { display: none; }
.slide.text .slide-text {
  display: block; max-width: 640px; padding: 32px 36px; border-radius: 16px; background: #fff; color: #17202e;
  box-shadow: 0 10px 40px rgba(16, 24, 40, .18); border-top: 5px solid #1d5fd1;
}
.slide-text h3 { margin: 0 0 10px; font-size: clamp(18px, 2.2vw, 26px); }
.slide-text p, .slide-text .li { margin: 0; color: #435066; font-size: clamp(14px, 1.5vw, 18px); line-height: 1.7; overflow-wrap: anywhere; }
/* 條列：編號固定在左欄，文字換行時對齊編號後的位置 */
.slide-text .li { display: grid; grid-template-columns: auto 1fr; column-gap: .4em; }
/* 網址連結要能點，蓋在 overlay 之上 */
.slide-text a { position: relative; z-index: 5; color: #1d5fd1; font-weight: 700; }
.slide-badge {
  position: absolute; left: 14px; top: 14px; padding: 4px 12px; border-radius: 999px;
  background: #1d5fd1; color: #fff; font-size: 12px; font-weight: 700; letter-spacing: .02em;
}
.overlay.awaiting { cursor: crosshair; }

/* 動手操作：暫停時的遮罩、熱點、提示框 */
.dim { position: absolute; inset: 0; background: rgba(8, 14, 26, .18); opacity: 0; transition: opacity .25s; pointer-events: none; }
.awaiting .dim { opacity: 1; }
.target {
  position: absolute; border-radius: 8px; pointer-events: none; opacity: 0;
  box-shadow: 0 0 0 3px #ffb020, 0 0 0 9999px rgba(8, 14, 26, .45);
  transition: opacity .3s;
}
.target.show { opacity: 1; animation: pulse 1.4s ease-in-out infinite; }
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 3px #ffb020, 0 0 0 9999px rgba(8, 14, 26, .45); }
  50% { box-shadow: 0 0 0 7px rgba(255, 176, 32, .55), 0 0 0 9999px rgba(8, 14, 26, .45); }
}
/* 觀看模式的黃框：由播放器依時間加上 .on，畫面一換就移除，不留殘影 */
.cue {
  position: absolute; display: none; border-radius: 6px; pointer-events: none;
  border: 3px solid #ffb020; box-shadow: 0 0 0 3px rgba(255, 176, 32, .25);
}
.cue.on { display: block; animation: cueIn .25s ease-out, cuePulse 1.2s ease-in-out .25s infinite; }
@keyframes cueIn { from { opacity: 0; transform: scale(1.25); } }
@keyframes cuePulse { 50% { box-shadow: 0 0 0 7px rgba(255, 176, 32, .15); } }
.ripple {
  position: absolute; width: 44px; height: 44px; margin: -22px 0 0 -22px; border-radius: 50%;
  pointer-events: none; animation: ripple .6s ease-out forwards;
}
.ripple.good { background: rgba(29, 154, 95, .45); border: 3px solid #2fd28a; }
.ripple.bad { background: rgba(226, 70, 44, .35); border: 3px solid #ff6a50; }
@keyframes ripple { from { transform: scale(.3); opacity: 1; } to { transform: scale(1.6); opacity: 0; } }

.task {
  position: absolute; left: 50%; bottom: 18px; transform: translate(-50%, 20px);
  display: flex; align-items: center; gap: 14px; max-width: calc(100% - 32px);
  padding: 12px 14px 12px 18px; border-radius: 16px;
  background: rgba(255, 255, 255, .97); color: #17202e; box-shadow: 0 12px 40px rgba(0, 0, 0, .35);
  opacity: 0; pointer-events: none; transition: opacity .25s, transform .25s;
}
.task.top { bottom: auto; top: 18px; }
.task.show { opacity: 1; transform: translate(-50%, 0); pointer-events: auto; }
.task.shake { animation: shake .4s; }
@keyframes shake { 20%, 60% { margin-left: -8px; } 40%, 80% { margin-left: 8px; } }
.task .num {
  flex: none; display: grid; place-items: center; width: 40px; height: 40px; border-radius: 12px;
  background: #e5eefc; color: #1d5fd1; font-weight: 800; font-size: 15px;
}
.task .txt { min-width: 0; }
.task .txt small { display: block; color: #5d6a7e; font-size: 12px; }
.task .txt strong { display: block; font-size: 16px; }
.task .acts { display: flex; gap: 6px; flex: none; }
.task .acts button { padding: 6px 12px; border-radius: 999px; background: #eef2f8; font-size: 13px; color: #17202e; }
.task .acts button:hover { background: #dfe5ee; }

/* 觀看模式字幕 */
.caption {
  position: absolute; left: 50%; bottom: 18px; transform: translateX(-50%);
  padding: 8px 18px; border-radius: 20px; background: rgba(13, 20, 32, .82); color: #fff; font-size: 15px; line-height: 1.5;
  opacity: 0; transition: opacity .3s; pointer-events: none; width: max-content; max-width: min(820px, calc(100% - 32px)); text-align: center;
}
.caption.show { opacity: 1; }

/* 步驟標頭：章節名稱以「步驟」開頭時，在該步驟開始時顯示 */
.heading {
  position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%) scale(.96);
  display: flex; flex-direction: column; align-items: center; gap: 10px; max-width: calc(100% - 48px);
  padding: 20px 36px; border-radius: 16px; background: rgba(13, 20, 32, .9); color: #fff; text-align: center;
  box-shadow: 0 16px 48px rgba(0, 0, 0, .35); opacity: 0; transition: opacity .3s, transform .3s; pointer-events: none;
}
.heading.show { opacity: 1; transform: translate(-50%, -50%) scale(1); }
.heading b { padding: 3px 14px; border-radius: 999px; background: #ffb020; color: #17202e; font-size: 14px; letter-spacing: .08em; }
.heading span { font-size: clamp(18px, 2.4vw, 28px); font-weight: 700; line-height: 1.4; }

/* 重點提示卡 */
.toasts { position: absolute; top: 14px; right: 14px; width: min(340px, 46%); display: flex; flex-direction: column; gap: 8px; pointer-events: none; }
.toast {
  display: flex; gap: 10px; padding: 12px 14px; border-radius: 12px; background: rgba(255, 255, 255, .97); color: #17202e;
  box-shadow: 0 10px 30px rgba(0, 0, 0, .3); border-left: 4px solid #1d5fd1; pointer-events: auto;
  animation: toastIn .35s ease-out;
}
.toast.warn { border-left-color: #e08a00; }
.toast.ok { border-left-color: #1d9a5f; }
.toast.out { animation: toastOut .3s ease-in forwards; }
.toast strong { display: block; font-size: 14px; }
.toast p { margin: 2px 0 0; font-size: 13px; color: #435066; line-height: 1.5; }
.toast .badge { flex: none; width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center; color: #fff; background: #1d5fd1; }
.toast.warn .badge { background: #e08a00; }
.toast.ok .badge { background: #1d9a5f; }
.toast .badge .ico { width: 15px; height: 15px; stroke-width: 2.6; }
@keyframes toastIn { from { opacity: 0; transform: translateX(24px); } }
@keyframes toastOut { to { opacity: 0; transform: translateX(24px); } }

/* 開始／結束畫面 */
.screen {
  position: absolute; inset: 0; z-index: 10; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 18px;
  text-align: center; color: var(--text); padding: 24px;
  background: radial-gradient(ellipse at center, rgba(255, 255, 255, .78), rgba(238, 242, 248, .92)); backdrop-filter: blur(6px);
  transition: opacity .3s, visibility 0s;
}
.screen.hide { opacity: 0; visibility: hidden; pointer-events: none; transition: opacity .3s, visibility 0s .3s; }
.screen h2 { margin: 0; font-size: clamp(20px, 3vw, 32px); letter-spacing: .02em; }
.screen p { margin: 0; color: var(--muted); max-width: 560px; font-size: clamp(13px, 1.4vw, 16px); }
.screen .row { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; }
.screen .choice {
  width: min(250px, 40vw); padding: 18px; border-radius: 16px; text-align: left; color: var(--text);
  background: var(--surface); border: 1px solid var(--line); box-shadow: var(--shadow);
  transition: background .2s, transform .2s;
}
.screen .choice:hover { border-color: var(--brand); transform: translateY(-2px); }
.screen .choice.primary { color: #fff; }
.screen .btn.ghost { background: var(--surface); color: var(--brand); border: 1px solid var(--line); }
.screen .choice.primary { background: var(--brand); border-color: transparent; }
.screen .choice .ico { width: 26px; height: 26px; margin-bottom: 8px; }
.screen .choice strong { display: block; font-size: 17px; }
.screen .choice span { font-size: 13px; color: var(--muted); }
.screen .choice.primary span { color: rgba(255, 255, 255, .85); }
.score { display: flex; gap: 28px; }
.score div { display: flex; flex-direction: column; }
.score b { font-size: clamp(26px, 4vw, 40px); line-height: 1.1; }
.score span { font-size: 13px; color: var(--muted); }

@media (max-width: 700px) {
  .topbar { flex-wrap: wrap; padding: 10px 16px; gap: 8px 12px; }
  .topbar .crumb { flex: 1; }
  .topbar .crumb small { display: none; }
  .topbar .spacer { display: none; }
  .seg { width: 100%; }
  .seg button { flex: 1; justify-content: center; white-space: nowrap; }
  .layout { padding: 16px; gap: 16px; }
  .screen { gap: 8px; padding: 10px; }
  .screen p, .screen .choice span, .screen .choice .ico { display: none; }
  .screen .choice { width: auto; padding: 8px 14px; }
  .screen .choice strong { font-size: 14px; }
  .screen .btn.small { padding: 4px 10px; font-size: 12px; }
  .task { padding: 8px 10px; gap: 8px; bottom: 8px; }
  .task.top { top: 8px; }
  .task .num { width: 32px; height: 32px; font-size: 12px; }
  .task .txt small { display: none; }
  .task .txt strong { font-size: 13px; }
  .toasts { width: 70%; top: 8px; right: 8px; }
  .toast p { display: none; }
  .controls .time { display: none; }
}

/* ---------- 控制列 ---------- */
.controls { display: flex; align-items: center; gap: 6px; padding: 8px 12px 10px; color: var(--text); background: var(--surface); border-top: 1px solid var(--line); }
.controls button { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 10px; color: var(--text); }
.controls button:hover { background: var(--surface-2); color: var(--brand); }
.controls button[hidden] { display: none; }
.controls button.off { color: #a3aec0; }
.controls .time { font-variant-numeric: tabular-nums; font-size: 13px; color: var(--muted); padding: 0 6px; white-space: nowrap; }
.controls .speed { width: auto; padding: 0 10px; font-size: 13px; font-weight: 700; }

.timeline { position: relative; flex: 1; height: 36px; cursor: pointer; }
.timeline .segs { position: absolute; left: 0; right: 0; top: 15px; height: 6px; display: flex; gap: 3px; }
.timeline .seg-bar { position: relative; height: 100%; background: #dfe5ee; border-radius: 3px; overflow: hidden; transition: transform .15s; }
.timeline:hover .seg-bar { transform: scaleY(1.5); }
.timeline .seg-bar i { position: absolute; inset: 0 auto 0 0; background: var(--brand); width: 0; }
.timeline .mk { position: absolute; top: 4px; width: 8px; height: 8px; margin-left: -4px; transform: rotate(45deg); border-radius: 2px; background: #ffb020; pointer-events: none; }
.timeline .mk.warn { background: #ff8a3d; }
.timeline .mk.ok { background: #2fd28a; }
.timeline .dot { position: absolute; top: 25px; width: 6px; height: 6px; margin-left: -3px; border-radius: 50%; background: #b7c2d3; pointer-events: none; }
.timeline .dot.done { background: #2fd28a; }
.timeline .head { position: absolute; top: 11px; width: 14px; height: 14px; margin-left: -7px; border-radius: 50%; background: #fff; border: 3px solid var(--brand); box-shadow: 0 0 0 4px rgba(29, 95, 209, .18); pointer-events: none; }
.timeline .tip {
  position: absolute; bottom: 34px; transform: translateX(-50%); padding: 6px 10px; border-radius: 8px;
  background: #fff; color: #17202e; font-size: 12px; white-space: nowrap; box-shadow: var(--shadow); border: 1px solid var(--line);
  opacity: 0; pointer-events: none; transition: opacity .15s;
}
.timeline:hover .tip { opacity: 1; }
.timeline .tip b { display: block; font-size: 13px; }

/* ---------- 側欄 ---------- */
.side { display: flex; flex-direction: column; gap: 16px; min-width: 0; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }
.progress-card { padding: 16px 18px; display: flex; align-items: center; gap: 14px; }
.ring { width: 54px; height: 54px; flex: none; }
.ring circle { fill: none; stroke-width: 6; }
.ring .bg { stroke: var(--surface-2); }
.ring .fg { stroke: var(--ok); stroke-linecap: round; transition: stroke-dashoffset .4s; transform: rotate(-90deg); transform-origin: center; }
.progress-card strong { display: block; font-size: 15px; }
.progress-card small { color: var(--muted); font-size: 13px; }

.tabs { display: flex; border-bottom: 1px solid var(--line); padding: 0 8px; }
.tabs button { padding: 12px 12px 10px; font-size: 14px; color: var(--muted); border-bottom: 2px solid transparent; margin-bottom: -1px; }
.tabs button.on { color: var(--brand); border-color: var(--brand); font-weight: 700; }
.panel { padding: 8px; max-height: calc(100vh - 290px); min-height: 200px; overflow: auto; }
@media (max-width: 1080px) { .panel { max-height: none; } }

.chap { border-radius: 12px; padding: 4px; }
.chap.cur { background: var(--brand-soft); }
.chap-h { display: flex; align-items: center; gap: 10px; width: 100%; padding: 8px; text-align: left; border-radius: 10px; }
.chap-h:hover { background: var(--surface-2); }
.chap.cur .chap-h:hover { background: transparent; }
.chap-h .n { flex: none; width: 28px; height: 28px; border-radius: 9px; display: grid; place-items: center; font-size: 13px; font-weight: 800; background: var(--surface-2); color: var(--muted); }
.chap.cur .chap-h .n { background: var(--brand); color: #fff; }
.chap.done .chap-h .n { background: var(--ok); color: #fff; }
.chap-h .t { flex: 1; min-width: 0; font-weight: 600; font-size: 14px; }
.chap-h .t small { display: block; font-weight: 400; color: var(--muted); font-size: 12px; }
.steps { list-style: none; margin: 2px 0 6px; padding: 0 0 0 22px; }
.steps li button { display: flex; gap: 8px; width: 100%; padding: 5px 8px; text-align: left; font-size: 13px; color: var(--muted); border-radius: 8px; }
.steps li button:hover { background: color-mix(in srgb, var(--surface-2) 70%, transparent); color: var(--text); }
.steps li .chk { flex: none; width: 16px; height: 16px; margin-top: 2px; border-radius: 50%; border: 2px solid var(--line); display: grid; place-items: center; }
.steps li.done .chk { background: var(--ok); border-color: var(--ok); color: #fff; }
.steps li.done .chk .ico { width: 10px; height: 10px; stroke-width: 3.5; }
.steps li.now button { color: var(--text); font-weight: 700; }
.steps li.now .chk { border-color: var(--brand); }

.note { display: flex; gap: 10px; width: 100%; padding: 10px; text-align: left; border-radius: 10px; }
.note:hover { background: var(--surface-2); }
.note .badge { flex: none; width: 26px; height: 26px; border-radius: 8px; display: grid; place-items: center; background: var(--brand-soft); color: var(--brand); }
.note.warn .badge { background: var(--warn-soft); color: var(--warn); }
.note.ok .badge { background: var(--ok-soft); color: var(--ok); }
.note .badge .ico { width: 15px; height: 15px; }
.note strong { display: block; font-size: 14px; }
.note p { margin: 2px 0 0; font-size: 13px; color: var(--muted); }
.note time { font-size: 12px; color: var(--brand); font-variant-numeric: tabular-nums; }
.empty { padding: 24px 12px; text-align: center; color: var(--muted); font-size: 14px; }

/* 快捷鍵說明：放在播放器正下方，手機沒有鍵盤時不顯示 */
.keys { padding: 10px 4px 0; font-size: 12px; color: var(--muted); display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 6px 16px; }
@media (max-width: 700px) { .keys { display: none; } }
kbd { font: inherit; font-size: 11px; padding: 1px 6px; border-radius: 5px; border: 1px solid var(--line); background: var(--surface-2); color: var(--text); }

/* ---------- 課程總覽 ---------- */
.hero {
  padding: 48px 24px 36px; color: #fff;
  background: linear-gradient(120deg, #123d8a 0%, #1d5fd1 55%, #2d7ff0 100%);
}
.hero .in { max-width: 1240px; margin: 0 auto; }
.hero small { opacity: .8; letter-spacing: .08em; }
.hero h1 { margin: 6px 0 8px; font-size: clamp(26px, 4vw, 38px); }
.hero p { margin: 0; opacity: .88; }
.hero .stats { display: flex; gap: 28px; margin-top: 22px; flex-wrap: wrap; }
.hero .stats b { display: block; font-size: 26px; line-height: 1.2; }
.hero .stats span { font-size: 13px; opacity: .8; }
.wrap { max-width: 1240px; margin: 0 auto; padding: 24px; }
.filters { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 20px; }
.filters button { padding: 8px 16px; border-radius: 999px; background: var(--surface); border: 1px solid var(--line); font-size: 14px; color: var(--muted); }
.filters button.on { background: var(--brand); border-color: var(--brand); color: #fff; font-weight: 700; }
.sys-h { display: flex; align-items: baseline; gap: 10px; margin: 28px 0 14px; }
.sys-h h2 { margin: 0; font-size: 20px; }
.sys-h span { color: var(--muted); font-size: 14px; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 18px; }
.lesson { display: flex; flex-direction: column; overflow: hidden; transition: transform .2s, box-shadow .2s; }
.lesson:hover { transform: translateY(-3px); box-shadow: 0 2px 4px rgba(16, 24, 40, .06), 0 16px 36px rgba(16, 24, 40, .14); }
.lesson .thumb { position: relative; aspect-ratio: 16 / 8.5; background: #0d1420 center / cover no-repeat; }
.lesson .thumb::after { content: ""; position: absolute; inset: 0; background: linear-gradient(180deg, transparent 50%, rgba(0, 0, 0, .55)); }
.lesson .thumb .dur { position: absolute; right: 10px; bottom: 8px; z-index: 1; color: #fff; font-size: 12px; font-weight: 700; padding: 2px 8px; border-radius: 6px; background: rgba(0, 0, 0, .55); }
.lesson .thumb .tag { position: absolute; left: 10px; top: 10px; z-index: 1; display: inline-flex; align-items: center; gap: 4px; padding: 3px 10px; border-radius: 999px; font-size: 12px; font-weight: 700; background: #ffb020; color: #3a2400; }
.lesson .thumb .tag .ico { width: 13px; height: 13px; stroke-width: 2.6; }
.lesson .thumb .play { position: absolute; inset: 0; margin: auto; z-index: 1; width: 52px; height: 52px; border-radius: 50%; display: grid; place-items: center; background: rgba(255, 255, 255, .92); color: #1d5fd1; opacity: 0; transform: scale(.85); transition: opacity .2s, transform .2s; }
.lesson:hover .thumb .play { opacity: 1; transform: scale(1); }
.lesson .bar { height: 4px; background: var(--surface-2); }
.lesson .bar i { display: block; height: 100%; background: var(--ok); }
.lesson .body { padding: 14px 16px 16px; display: flex; flex-direction: column; gap: 4px; flex: 1; }
.lesson .body small { color: var(--brand); font-size: 12px; font-weight: 700; }
.lesson .body strong { font-size: 16px; }
.lesson .body p { margin: 0; color: var(--muted); font-size: 13px; flex: 1; }
.lesson .meta { display: flex; justify-content: space-between; align-items: center; margin-top: 10px; font-size: 12px; color: var(--muted); }
.lesson .meta .st { font-weight: 700; }
.lesson .meta .st.done { color: var(--ok); }
.lesson .meta .st.go { color: var(--brand); }