/* web.css — DES201 web lessons (หน้าเลื่อนอ่าน + ฉากอนิเมชัน) */
@font-face{font-family:'Sarabun';font-weight:400;font-display:swap;src:url('../vendor/fonts/sarabun-thai-400-normal.woff2') format('woff2');}
@font-face{font-family:'Sarabun';font-weight:400;font-display:swap;src:url('../vendor/fonts/sarabun-latin-400-normal.woff2') format('woff2');unicode-range:U+0000-024F,U+2000-206F;}
@font-face{font-family:'Sarabun';font-weight:500;font-display:swap;src:url('../vendor/fonts/sarabun-thai-500-normal.woff2') format('woff2');}
@font-face{font-family:'Sarabun';font-weight:500;font-display:swap;src:url('../vendor/fonts/sarabun-latin-500-normal.woff2') format('woff2');unicode-range:U+0000-024F,U+2000-206F;}
@font-face{font-family:'Sarabun';font-weight:600;font-display:swap;src:url('../vendor/fonts/sarabun-thai-600-normal.woff2') format('woff2');}
@font-face{font-family:'Sarabun';font-weight:600;font-display:swap;src:url('../vendor/fonts/sarabun-latin-600-normal.woff2') format('woff2');unicode-range:U+0000-024F,U+2000-206F;}
@font-face{font-family:'Sarabun';font-weight:700;font-display:swap;src:url('../vendor/fonts/sarabun-thai-700-normal.woff2') format('woff2');}
@font-face{font-family:'Sarabun';font-weight:700;font-display:swap;src:url('../vendor/fonts/sarabun-latin-700-normal.woff2') format('woff2');unicode-range:U+0000-024F,U+2000-206F;}

:root{
  --ink:#16233A; --ink2:#3E4C63; --muted:#7C8AA0; --line:#E3E9F0; --soft:#F6F9FC; --paper:#FFFFFF;
  --blue:#2563EB; --blue-bg:#EFF6FF; --blue-ln:#BFDBFE;
  --amber:#C2740A; --amber-bg:#FFFAEB; --amber-ln:#FCD98A;
  --green:#047857; --green-bg:#ECFDF5; --green-ln:#9CE6C6;
  --rose:#D01A46; --rose-bg:#FFF1F3; --rose-ln:#FBC5D0;
  --violet:#6D3BE4; --violet-bg:#F4F2FF; --violet-ln:#D6CCFB;
  --teal:#0E7490; --teal-bg:#ECFEFF; --teal-ln:#A5E8F2;
  --hi:#FDE68A; --r:14px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:#F3F6FA;color:var(--ink);font-family:'Sarabun','Leelawadee UI','Segoe UI',system-ui,sans-serif;font-size:17px;line-height:1.8;-webkit-font-smoothing:antialiased}
.wrap{max-width:980px;margin:0 auto;padding:18px 18px 80px}
b,strong{font-weight:700;color:#0E1B30}
a{color:var(--blue);text-decoration:none}
.katex{font-size:1.06em}

/* ---------- หัวตอน ---------- */
.ep-head{padding:26px 26px 20px;background:var(--paper);border:1.5px solid var(--line);border-radius:var(--r);margin-bottom:18px;
  background-image:radial-gradient(700px 300px at 8% 0%,#EEF4FF 0%,rgba(255,255,255,0) 60%)}
.ep-head .eyebrow{font-size:13px;font-weight:700;letter-spacing:.12em;color:var(--blue)}
.ep-head h1{font-size:30px;line-height:1.3;margin:6px 0 4px;letter-spacing:-.01em}
.ep-head .sub{color:var(--ink2);margin:0 0 10px}
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:8px}
.chip{display:inline-flex;align-items:center;gap:6px;font-size:13.5px;font-weight:600;padding:4px 11px;border-radius:999px;border:1.5px solid var(--line);background:var(--soft);color:var(--ink2)}
.chip.have{border-color:var(--teal-ln);background:var(--teal-bg);color:var(--teal)}
.chip.time{border-color:var(--amber-ln);background:var(--amber-bg);color:var(--amber)}

/* ---------- ระหว่างฉาก: ข้อความสั้นๆ ---------- */
.note{background:var(--paper);border:1.5px solid var(--line);border-left:5px solid var(--blue);border-radius:10px;padding:12px 18px;margin:14px 0;font-size:16.5px}
.note.trap{border-left-color:var(--rose);background:var(--rose-bg)}
.note.tip{border-left-color:var(--green);background:var(--green-bg)}
.note.link{border-left-color:var(--teal);background:var(--teal-bg)}
.note .lab{display:inline-block;font-size:11.5px;font-weight:700;letter-spacing:.06em;padding:1px 9px;border-radius:999px;background:var(--blue);color:#fff;margin-right:8px;vertical-align:2px}
.note.trap .lab{background:var(--rose)} .note.tip .lab{background:var(--green)} .note.link .lab{background:var(--teal)}
h2.part{display:flex;align-items:center;gap:12px;font-size:22px;margin:30px 0 10px}
h2.part .n{flex:none;width:36px;height:36px;border-radius:10px;background:var(--blue);color:#fff;display:flex;align-items:center;justify-content:center;font-size:17px}
h2.part .bar{flex:1;height:2px;background:var(--line)}

/* ---------- ฉาก ---------- */
section.scene{background:var(--paper);border:1.5px solid var(--line);border-radius:var(--r);overflow:hidden;margin:14px 0 22px;box-shadow:0 1px 0 rgba(22,35,58,.03)}
section.scene .stage{position:relative;width:100%;aspect-ratio:16/9;background:#FBFDFF;border-bottom:1.5px solid var(--line);overflow:hidden}
section.scene .stage>svg{width:100%;height:100%;display:block}
section.scene .stage svg *{transform-box:fill-box;transform-origin:center}
section.scene .stage svg text{font-family:'Sarabun',sans-serif;user-select:none}
section.scene .stage .mark{filter:drop-shadow(0 0 6px #F59E0B) drop-shadow(0 0 14px #FCD34D)}
/* คำบรรยาย — ตัวใหญ่ อ่านสบาย ไฮไลต์ตามเสียง */
.cap{min-height:58px;padding:12px 22px 8px;font-size:18.5px;line-height:1.75;color:#9AA6B8}
.cap .capin span.on{color:var(--ink)}
.cap .capin{transition:color .2s}
/* คอนโทรล */
.ctl{display:flex;align-items:center;gap:12px;padding:8px 14px 12px;border-top:1px dashed var(--line)}
.btn{font:inherit;font-weight:700;font-size:15px;padding:7px 16px;border-radius:999px;border:1.5px solid var(--blue-ln);background:var(--blue-bg);color:var(--blue);cursor:pointer}
.btn:hover{background:#DBEAFE}
.btn.play{background:var(--blue);color:#fff;border-color:var(--blue);min-width:112px}
.btn.replay{min-width:0;padding:7px 12px}
.dots{display:flex;flex-wrap:wrap;gap:6px;flex:1}
.dot{width:12px;height:12px;border-radius:50%;border:2px solid var(--blue-ln);background:#fff;padding:0;cursor:pointer}
.dot.on{background:var(--blue);border-color:var(--blue)}
.dot:hover{transform:scale(1.25)}
.time{font-variant-numeric:tabular-nums;font-size:13.5px;color:var(--muted);min-width:80px;text-align:right}
section.scene .stitle{position:absolute;right:14px;top:10px;font-size:13px;font-weight:700;color:var(--muted);letter-spacing:.04em;pointer-events:none;background:rgba(255,255,255,.7);padding:2px 8px;border-radius:999px}

/* ---------- โจทย์ + เฉลยกดเปิด ---------- */
.q{background:var(--paper);border:1.5px solid var(--line);border-radius:var(--r);margin:14px 0;overflow:hidden}
.q .qh{display:flex;align-items:center;gap:10px;padding:8px 16px;background:#F1F5FB;border-bottom:1.5px solid var(--line);font-size:13.5px;font-weight:700;color:var(--ink2)}
.q .qh .src{margin-left:auto;font-weight:600;color:var(--muted);font-size:12.5px}
.q .qen{padding:12px 18px 6px;font-size:16.5px;line-height:1.7}
.q .qth{padding:0 18px 12px;color:var(--ink2);font-size:15px}
.q details{border-top:1.5px dashed var(--line)}
.q summary{cursor:pointer;padding:10px 18px;font-weight:700;color:var(--green);list-style:none;display:flex;align-items:center;gap:8px}
.q summary::before{content:'▸';transition:transform .2s}
.q details[open] summary::before{transform:rotate(90deg)}
.q details section.scene{margin:0;border:0;border-radius:0;box-shadow:none}
.q .choices{display:flex;flex-wrap:wrap;gap:8px;padding:6px 18px 12px}
.q .choice{font:inherit;font-size:15.5px;padding:6px 14px;border-radius:10px;border:1.5px solid var(--line);background:var(--soft);cursor:pointer}
.q .choice.ok{border-color:var(--green);background:var(--green-bg);color:var(--green);font-weight:700}
.q .choice.no{border-color:var(--rose);background:var(--rose-bg);color:var(--rose)}

/* ---------- สรุป / ตอนต่อไป ---------- */
.sum{background:#0E1B30;color:#E8EEF8;border-radius:var(--r);padding:20px 22px;margin:20px 0}
.sum h3{color:#fff;margin:0 0 10px;font-size:20px}
.sum .card{background:rgba(255,255,255,.07);border:1px solid rgba(255,255,255,.14);border-radius:10px;padding:10px 14px;margin-bottom:8px}
.sum .card .ct{color:#93C5FD;font-weight:700;margin-bottom:2px}
.sum p{margin:.15em 0;color:#D8E2F0;font-size:16px}
.sum b{color:#fff} .sum .k{color:#FCD34D;font-weight:700}
.next{display:flex;align-items:center;justify-content:space-between;gap:12px;background:var(--paper);border:1.5px solid var(--line);border-radius:var(--r);padding:14px 20px;margin:16px 0}
.next a.btn{font-size:16px}
footer{color:var(--muted);font-size:13px;text-align:center;margin-top:30px}

/* ---------- หน้าแรกของคอร์ส ---------- */
.eplist{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:12px}
.epcard{display:block;background:var(--paper);border:1.5px solid var(--line);border-radius:var(--r);padding:14px 16px;color:inherit}
.epcard:hover{border-color:var(--blue-ln);box-shadow:0 4px 18px rgba(37,99,235,.08)}
.epcard .no{font-size:12.5px;font-weight:700;color:var(--blue);letter-spacing:.06em}
.epcard .tt{font-weight:700;font-size:17px;margin:2px 0}
.epcard .dd{color:var(--muted);font-size:14px}
.epcard.soon{opacity:.55;pointer-events:none}

@media (max-width:640px){body{font-size:16px}.wrap{padding:10px 10px 60px}.ep-head{padding:18px}.ep-head h1{font-size:24px}.cap{font-size:17px}}

/* ---- ตอบโต้: แผงคำถาม / หยุดคิด + ปุ่มฟังซ้ำ ---- */
.ask{margin:0 22px 12px;padding:12px 16px 14px;border:2px solid #F5D08A;background:#FFFBEB;border-radius:12px}
.ask .asklab{font-size:12.5px;font-weight:700;letter-spacing:.04em;color:#B45309;margin-bottom:4px}
.ask .askq{font-weight:700;font-size:17.5px;line-height:1.6;color:var(--ink);margin-bottom:8px}
.ask .choices{display:flex;flex-wrap:wrap;gap:8px;margin:4px 0 6px}
.ask .choice{font:inherit;font-size:16px;padding:8px 16px;border-radius:10px;border:1.5px solid var(--line);background:#fff;cursor:pointer}
.ask .choice:hover:not(:disabled){border-color:var(--blue-ln);background:var(--blue-bg)}
.ask .choice.ok{border-color:var(--green);background:var(--green-bg);color:var(--green);font-weight:700}
.ask .choice.no{border-color:var(--rose);background:var(--rose-bg);color:var(--rose)}
.ask .choice:disabled{cursor:default;opacity:.85}
.ask .askin{display:flex;gap:8px;align-items:center;margin:4px 0 6px}
.ask input{font:inherit;font-size:16.5px;padding:7px 12px;border:1.5px solid var(--line);border-radius:10px;min-width:180px;background:#fff}
.ask input.ok{border-color:var(--green);background:var(--green-bg);color:var(--green);font-weight:700}
.ask input.no{border-color:var(--rose);background:var(--rose-bg)}
.ask .askfb{font-size:15.5px;line-height:1.6}
.ask .askfb.ok .askr{color:var(--green);font-weight:700}
.ask .askfb.no .askr{color:var(--rose);font-weight:700}
.ask .btn.go{margin-top:8px;background:var(--green);border-color:var(--green);color:#fff}
.ask .btn.go:hover{filter:brightness(1.08)}
.ask.nudge{animation:asknudge .45s}
@keyframes asknudge{0%,100%{transform:none}20%{transform:translateX(-7px)}60%{transform:translateX(7px)}}
.ctl .grp{display:inline-flex;gap:4px}
.btn.sm{padding:7px 10px;min-width:0;font-size:13px}
.ctl .tally{font-size:13.5px;font-weight:700;color:var(--green);min-width:0}
.ctl .spd{font:inherit;font-size:13px;border:1.5px solid var(--line);border-radius:8px;padding:4px 6px;background:#fff;color:var(--ink2)}
.dot.ask{border-color:#D97706;background:#FEF3C7}
.dot.ask.on{background:#D97706;border-color:#D97706}

/* ---- มือถือ: แถบควบคุมขึ้นแถวใหม่ได้ ไม่ถูกตัด (รีวิว 5 ก.ย.: ปุ่มความเร็ว/เริ่มใหม่หลุดจอที่ 390px) ---- */
.ctl{flex-wrap:wrap;row-gap:8px}
.ctl .dots{flex:1 1 120px;min-width:0}
@media (max-width:640px){
  .ctl{gap:8px;padding:8px 10px 10px}
  .btn{font-size:14px;padding:6px 12px}
  .btn.play{min-width:0;flex:1 1 auto}
  .time{min-width:0;font-size:12.5px}
  .ctl .dots{flex:1 1 100%;order:9}
  .cap{font-size:16px;padding:10px 14px 6px}
  .ask{margin:0 10px 10px}
}
/* ---- ขยายเต็มจอ: ทั้งฉาก (เวที+คำบรรยาย+ปุ่ม) ทับหน้าจอ · มือถือหมุนแนวนอนจะได้เวทีเต็มความกว้าง ---- */
section.scene.zoom{position:fixed;inset:0;z-index:999;margin:0;border-radius:0;border:0;overflow:hidden;background:var(--paper);display:flex;flex-direction:column}
/* ขนาดเวทีมาจาก player.js `_fitZoom()` ซึ่งวัดความสูงจริงของคำบรรยาย+ปุ่ม แล้วคำนวณให้พอดีจอ
   (ของเดิมใช้ค่าคงที่ calc((100vh - 150px)*16/9) ซึ่งวัดจริงแล้วเผื่อขาดไป ~260px) */
section.scene.zoom .stage{flex:0 0 auto;margin:0 auto;aspect-ratio:auto}
section.scene.zoom .cap{flex:1 1 auto;min-height:0;max-height:none;overflow:auto}
section.scene.zoom .ask{flex:0 0 auto;max-height:46vh;overflow:auto}
section.scene.zoom .ctl{flex:0 0 auto;flex-wrap:wrap}
/* ในโหมดเต็มจอเอาของที่ไม่ใช่การเล่นออก คืนพื้นที่ให้เวที 126px (ผู้ใช้ตัดสิน 18 ก.ย.) */
section.scene.zoom .lesson-timeline,
section.scene.zoom .question-list{display:none}
section.scene.zoom:fullscreen{background:var(--paper)}
body.haszoom{overflow:hidden}
/* โหมดจอสงบ (ทดลอง 18 ก.ย. 2569): ลดสิ่งที่แย่งสายตาโดยไม่เอาข้อมูลออก
   ป้ายที่จอดไว้ในแถบซ้ายยังอยู่ครบ แค่หรี่ลง — สว่างเต็มเมื่อเอาเมาส์ไปวาง ยังอ่านย้อนได้ */
body.calm .stage .kparked{opacity:.32;transition:opacity .25s}
body.calm .stage .kparked:hover{opacity:1}
body.calm .cap .capin span{color:inherit}
.btn.calm.on{background:#244d44;color:#baffd8;border-color:#568a75}
.btn.auto.on{background:var(--green);border-color:var(--green);color:#fff}
/* โฟกัสอัตโนมัติ: หรี่ทุกชิ้นที่ไม่ใช่สิ่งที่กำลังพูดถึง (ใช้ filter จึงไม่ชนกับ style.opacity ของอนิเมชัน) · viewBox ถูกซูมโดย player.js */
.btn.foc.on{background:#3569B1;border-color:#3569B1;color:#fff}
.stage svg.focusing [data-dim]{filter:opacity(.14) saturate(.4);transition:filter .35s ease}
.stage svg{transition:none}

/* ORBIT / Sci-fi pixel study station. Local art, no additional font requests. */
:root{
 --ink:#e6f0ff;--ink2:#bdcee4;--muted:#94a9c6;--line:#2c4160;--soft:#13243a;--paper:#0e1b2e;
 --blue:#72f1de;--blue-bg:#143b40;--blue-ln:#38746f;--teal:#72e4ef;--teal-bg:#123440;--teal-ln:#326776;
 --green:#a8f2a0;--green-bg:#17382c;--green-ln:#497b57;--amber:#f4d386;--amber-bg:#3a3020;--amber-ln:#776342;
 --rose:#ff9fb7;--rose-bg:#3c243b;--rose-ln:#825071;--violet:#c4aeff;--violet-bg:#292343;--violet-ln:#625080;--r:3px;
 color-scheme:dark;
}
body{background-color:#080f1d;background-image:radial-gradient(circle at 75% 0%,#1f2450 0,transparent 44%),radial-gradient(#30435d 1px,transparent 1px);background-size:auto,40px 40px;background-attachment:fixed}
.wrap{max-width:1120px;padding-top:32px}
body strong,body b{color:var(--ink)}
body .ep-head{position:relative;isolation:isolate;overflow:hidden;padding:32px;background:#101e32;border:1px solid #3c5874;border-top:3px solid var(--blue);border-radius:3px;box-shadow:5px 5px 0 #030914;margin-bottom:24px}
@media(min-width:980px){body .ep-head{padding-right:310px}}
@media(min-width:641px) and (max-width:979px){body .ep-head::after{opacity:.24}}
.ep-head::after{content:'';position:absolute;z-index:-1;inset:0;background:linear-gradient(90deg,#101e32 0%,#101e32e6 48%,transparent 72%),url('orbit.svg') right center/360px auto no-repeat;opacity:.8;pointer-events:none}
.ep-head .eyebrow{font:700 12px/1.8 'Sarabun',sans-serif;letter-spacing:.14em;color:#8ef4df}
.ep-head .eyebrow::before{content:'✦ ';color:#c4aeff}
.ep-head h1{font-size:clamp(26px,3.5vw,42px);max-width:760px;line-height:1.38;margin:12px 0}
.ep-head .sub{max-width:670px;font-size:16px;color:#bdcee4}
.ep-head .chips{margin-top:22px}
body .chip{border-radius:2px;padding:4px 10px;font-size:12.5px}
body .subgrid{grid-template-columns:repeat(auto-fit,minmax(min(100%,290px),1fr));gap:20px;margin-top:24px}
body .subcard{padding:26px 24px 22px;min-height:238px;border:1px solid var(--line);border-radius:3px;background:linear-gradient(145deg,#17283f,#0e1b2e);box-shadow:4px 4px 0 #030914;overflow:visible}
body .subcard .rail{width:3px;inset:18px auto 18px -1px}
body .subcard::before{content:'↗';position:absolute;right:18px;top:16px;color:#6985a8;font-family:monospace;font-size:22px}
body .subcard .code{font-family:monospace;font-size:13px;letter-spacing:.16em}
body .subcard h3{font-size:23px;margin-top:14px;margin-right:10px;color:#edf5ff}
body .subcard .th{font-size:13px;color:#91a9c9;line-height:1.6}
body .subcard .bl{color:#bdcee4;line-height:1.7;margin:14px 0 20px}
body .subcard:hover,body .epcard:hover{border-color:#72f1de;box-shadow:4px 4px 0 #245d5d;transform:translate(-1px,-2px)}
body .epcard{border-radius:3px;padding:20px;background:linear-gradient(135deg,#15263b,#0e1b2e);box-shadow:3px 3px 0 #030914;transition:transform .15s,border-color .15s}
.epcard .no{font-family:monospace;font-size:13px}.epcard .tt{font-size:19px;margin:8px 0}
body .scene{border-radius:3px;border:1px solid #3a526f;box-shadow:5px 5px 0 #030914}
body .scene .stage{
 --ink:#16233a;--ink2:#3e4c63;--muted:#60738d;--line:#e3e9f0;--soft:#f6f9fc;--paper:#fff;
 --blue:#2563eb;--blue-bg:#eff6ff;--blue-ln:#bfdbfe;--green:#047857;--green-bg:#ecfdf5;--green-ln:#9ce6c6;
 --amber:#c2740a;--amber-bg:#fffaeb;--amber-ln:#fcd98a;--rose:#d01a46;--rose-bg:#fff1f3;--rose-ln:#fbc5d0;
 --violet:#6d3be4;--violet-bg:#f4f2ff;--violet-ln:#d6ccfb;--teal:#0e7490;--teal-bg:#ecfeff;--teal-ln:#a5e8f2;
 color:#16233a;color-scheme:light;background:#fbfdff;border-bottom:3px solid #456180;
}
body .cap{background:#101e32;color:#8499b6;padding-top:18px;padding-bottom:14px}
body .cap .capin span.on{color:#e9f6ff}
body .ctl{padding:12px 14px;background:#0b1728;border-top:1px solid #314965;gap:10px}
body .btn{border-radius:2px;box-shadow:0 3px 0 #030914;transition:background .12s,transform .12s}
body .btn:hover{background:#234f58}
body .btn:active{transform:translateY(2px);box-shadow:none}
body .btn.play{background:#83f0dc;color:#092723;border-color:#b7ffef;min-width:136px}
body .btn.play:hover{background:#afffe9}
body .btn.auto.on,body .btn.foc.on{background:#244d44;color:#baffd8;border-color:#568a75}
body .dot{border-radius:0;width:14px;height:14px;background:#142a43;border-color:#497092;box-shadow:0 2px 0 #030914}
body .dot.on{background:#80f3de;border-color:#80f3de}
body .dot.ask{background:#3a3020;border-color:#c8a964}
body .dot.ask.on{background:#f4d386;border-color:#f4d386}
body .ctl .spd{border-radius:2px;background:#12263c;color:#dbedff;border-color:#3c5874}
body .time{font-family:monospace;font-size:12px;color:#a6bad3}
body .ask{background:#172a39;border:1px solid #577065;border-left:4px solid #a8f2a0;border-radius:2px;padding:18px 20px}
body .ask .asklab{color:#b4f8b1;letter-spacing:.02em}
body .ask .choice,body .ask input{background:#0c192a;color:#e6f0ff;border-color:#58708e;border-radius:2px}
body .ask .choice.ok{background:#17382c;color:#a8f2a0;border-color:#a8f2a0}
body .ask .choice.no{background:#3c243b;color:#ff9fb7;border-color:#ff9fb7}
body .ask .btn.go{background:#a8f2a0;color:#102b1e;border-color:#ccffc5}
body .q .qh{background:#192b42}
body .note,body .q,body .next,body h2.part .n{border-radius:2px}
body .note .lab,body h2.part .n{color:#08271f}
body .crumb{margin-bottom:18px}
body :focus-visible{outline:3px solid #e1b7ff;outline-offset:4px}
body footer{font-size:12px;color:#94a9c6;letter-spacing:.03em;padding:20px 0;border-top:1px solid #263950}
@media(max-width:640px){
 .wrap{padding:16px 12px 48px}body .ep-head{padding:24px 20px}.ep-head::after{opacity:.3;background-position:right top;background-size:auto,260px auto}.ep-head h1{font-size:27px}.ep-head .sub{font-size:15px}
 body .subcard{min-height:0;padding:22px}body .ctl{padding:12px 10px;gap:8px}body .btn.play{min-width:0}body .ask{padding:14px}.ask .askin{flex-wrap:wrap}.ask input{min-width:0;width:min(100%,240px)}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}body .subcard,body .epcard,body .btn{transition:none}.ask.nudge{animation:none}}
/* Question dots and Next controls share legacy class names with full panels. */
body .ctl .dot{padding:0;margin:0;min-width:14px;min-height:14px;width:14px;height:14px;align-self:center;border-width:2px;border-radius:0}
body .ctl .grp .btn{margin:0;display:inline-flex;align-items:center;justify-content:center;padding:7px 10px;min-height:36px}

/* Drag-to-seek transport and explicit, durable question resets. */
.dots[hidden]{display:none!important}
.lesson-timeline{padding:10px 18px 4px;background:var(--paper)}
.lesson-scrub{display:block;width:100%;height:28px;margin:0;accent-color:var(--blue);cursor:pointer;touch-action:pan-y}
.question-marks{position:relative;height:22px;margin:0 8px}
.question-marker{position:absolute;top:0;transform:translateX(-50%);width:18px;height:18px;border:2px solid var(--amber);background:var(--amber-bg);border-radius:3px;padding:0;cursor:pointer}
.question-marker.answered{border-color:var(--green);background:var(--green-bg)}
.load-status{display:block;min-height:20px;font-size:12px;color:var(--muted)}
.question-list{padding:10px 18px;border-top:1px solid var(--line);font-size:14px}
.question-list>summary{color:var(--ink2);cursor:pointer}
.question-row{display:flex;gap:12px;align-items:center;justify-content:space-between;margin:12px 0}
.question-row>span{flex:1;min-width:0}.question-row button{flex:none}
@media(max-width:640px){.lesson-timeline{padding:8px 12px 2px}.question-list{padding:10px 12px}.question-row{align-items:flex-start;flex-wrap:wrap}}