/* ============================================================
   麦弗逊式独立悬架 · 15分钟课堂教学展示（大字数智版）
   ============================================================ */
:root{
  --bg:#05111d;
  --bg2:#0a2438;
  --ink:#f2f8fc;
  --soft:#bdd5e4;
  --muted:#89a7ba;
  --dim:#5f7f94;
  --cyan:#5ce1ff;
  --blue:#3f8cff;
  --gold:#e2b76b;
  --red:#e15a4b;
  --line:rgba(120,190,225,.22);
  --line2:rgba(120,190,225,.1);
  --glass:rgba(8,28,46,.72);
  --sans:"Noto Sans SC","Microsoft YaHei","PingFang SC",sans-serif;
  --num:"Bahnschrift","DIN Alternate","Arial Narrow",sans-serif;
  --ease:cubic-bezier(.22,.8,.22,1);
}
*{box-sizing:border-box}
html,body{height:100%;margin:0;overflow:hidden;background:#030a11}
body{font-family:var(--sans);color:var(--ink);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;user-select:none}
a{color:inherit;text-decoration:none}
button{font-family:inherit;appearance:none}
svg{display:block}
.viewport{position:fixed;inset:0;display:grid;place-items:center;background:radial-gradient(ellipse at 50% 40%,#0a2134,#030a11 72%)}
.stage{width:1600px;height:900px;position:relative;overflow:hidden;transform:scale(var(--s,1));transform-origin:center;background:
  radial-gradient(900px 650px at 58% 42%,#0c314b 0,#071a2a 52%,#04101a 100%);
  box-shadow:0 40px 120px rgba(0,0,0,.45)}
.stage::before{content:"";position:absolute;inset:0;z-index:0;background-image:
  linear-gradient(rgba(110,190,230,.055) 1px,transparent 1px),
  linear-gradient(90deg,rgba(110,190,230,.055) 1px,transparent 1px);
  background-size:64px 64px;
  mask:radial-gradient(ellipse at 55% 42%,#000 8%,transparent 82%);
  -webkit-mask:radial-gradient(ellipse at 55% 42%,#000 8%,transparent 82%)}
.stage::after{content:"";position:absolute;inset:0;z-index:0;pointer-events:none;
  background:radial-gradient(ellipse at center,transparent 45%,rgba(0,0,0,.45) 100%)}

/* chrome */
.topbar{position:absolute;left:0;right:0;top:0;height:80px;z-index:50;display:flex;align-items:center;justify-content:space-between;padding:0 72px;border-bottom:1px solid var(--line2)}
.topbar .course{display:flex;align-items:center;gap:12px;font-size:18px;letter-spacing:.5px;color:var(--soft);white-space:nowrap}
.topbar .course b{color:var(--ink);font-weight:700}
.topbar .course .dot{color:var(--red)}
.topbar .course em{font-style:normal;color:var(--muted);font-size:16px}
.topbar .right{display:flex;align-items:center;gap:22px}
.page{font-family:var(--num);font-size:15px;letter-spacing:2px;color:var(--muted)}
.logo-plaque{background:#f7f4ec;padding:5px 10px;border-radius:3px;box-shadow:0 6px 18px rgba(0,0,0,.25)}
.logo-plaque img{width:152px;height:40px;object-fit:contain;display:block}
.footer{position:absolute;left:72px;right:72px;bottom:18px;height:34px;z-index:42;display:flex;align-items:flex-end;justify-content:space-between;border-top:1px solid var(--line2);padding-top:6px;font-size:13px;color:var(--dim);letter-spacing:.3px}
.footer .mid{color:#7794a6}
.footer .num{font-family:var(--num);letter-spacing:1.5px}
.carline{position:absolute;left:0;right:0;bottom:-28px;width:100%;height:180px;z-index:0;color:rgba(100,190,230,.13);pointer-events:none}

/* deck */
.deck{position:absolute;inset:0;z-index:10;overflow:hidden}
.track{display:flex;width:100%;height:100%;will-change:transform;transition:transform .9s var(--ease)}
.slide{position:relative;flex:0 0 100%;width:100%;height:100%;overflow:hidden;background:transparent}

/* reveal */
.s-head,.s-body,.cover-copy,.cover-visual{opacity:0;transform:translateY(14px);transition:opacity .75s ease,transform .75s var(--ease)}
.slide.active .s-head{opacity:1;transform:none;transition-delay:.05s}
.slide.active .s-body{opacity:1;transform:none;transition-delay:.14s}
.slide.active .cover-copy{opacity:1;transform:none;transition-delay:.08s}
.slide.active .cover-visual{opacity:1;transform:none;transition-delay:.2s}

/* type */
.s-head{position:absolute;left:72px;right:72px;top:104px;z-index:2}
.kicker{display:flex;align-items:center;gap:12px;font-family:var(--num);font-size:16px;letter-spacing:3px;color:var(--gold);text-transform:uppercase}
.kicker::before{content:"";width:38px;height:2px;background:var(--gold);border-radius:2px}
h1{font-family:var(--sans);font-size:52px;line-height:1.14;letter-spacing:.5px;margin:12px 0 12px;font-weight:700;color:#fff;max-width:1380px}
.sub{font-size:25px;line-height:1.6;color:var(--soft);max-width:1180px;margin:0;font-weight:400}
.rule{position:absolute;left:72px;right:72px;top:286px;height:1px;background:linear-gradient(90deg,rgba(226,183,107,.55),rgba(120,190,225,.14),transparent)}
.s-body{position:absolute;left:72px;right:72px;top:310px;bottom:78px;z-index:2}
.lab-slide .s-body{top:292px}

/* primitives */
.card{background:linear-gradient(145deg,rgba(10,36,56,.78),rgba(5,20,33,.84));border:1px solid var(--line);border-radius:14px;box-shadow:0 18px 46px rgba(0,0,0,.24);position:relative;overflow:hidden}
.card::before{content:"";position:absolute;left:0;top:18px;bottom:18px;width:3px;border-radius:3px;background:var(--gold);opacity:.8}
.btn{display:inline-flex;align-items:center;gap:10px;height:48px;padding:0 22px;border-radius:8px;border:1px solid var(--gold);background:var(--gold);color:#1a1207;font-size:19px;font-weight:700;cursor:pointer;transition:.25s}
.btn:hover{filter:brightness(1.07);transform:translateY(-1px)}
.btn.ghost{background:transparent;color:var(--soft);border-color:var(--line)}
.btn.ghost:hover{border-color:var(--cyan);color:#fff;background:rgba(92,225,255,.06)}
.badge{display:inline-flex;align-items:center;gap:8px;height:32px;padding:0 13px;border-radius:99px;border:1px solid rgba(226,183,107,.4);background:rgba(226,183,107,.07);color:var(--gold);font-size:15px;letter-spacing:.8px;width:max-content}
.badge.cyan{border-color:rgba(92,225,255,.35);background:rgba(92,225,255,.06);color:var(--cyan)}
.tag{font-family:var(--num);font-size:14px;letter-spacing:2px;color:var(--gold)}
.num{font-family:var(--num);font-variant-numeric:tabular-nums}
.note{font-size:14px;line-height:1.7;color:var(--dim);letter-spacing:.2px}
.red{color:var(--red)}.gold{color:var(--gold)}.cyan{color:var(--cyan)}.soft{color:var(--soft)}.muted{color:var(--muted)}

/* cover */
.cover-copy{position:absolute;left:72px;top:126px;width:840px;z-index:3}
.cover-eyebrow{display:flex;align-items:center;gap:12px;font-family:var(--num);font-size:16px;letter-spacing:3px;color:var(--gold)}
.cover-eyebrow::before{content:"";width:42px;height:1px;background:var(--gold)}
.cover h1{font-size:80px;line-height:1.06;margin:26px 0 12px;letter-spacing:2px}
.cover h1 em{font-style:normal;color:var(--gold)}
.cover-sub{font-size:28px;color:#c9dfea;letter-spacing:1px;margin-top:6px}
.cover-line{width:420px;height:1px;background:linear-gradient(90deg,var(--red),rgba(226,183,107,.7),transparent);margin:30px 0 24px}
.cover-meta{display:flex;gap:48px;font-size:17px;line-height:1.9;color:var(--soft)}
.cover-meta b{display:block;color:#fff;font-size:22px;font-weight:700;letter-spacing:.5px}
.cover-meta span{display:block;font-size:12px;letter-spacing:2px;color:var(--muted);margin-bottom:4px}
.cover-visual{position:absolute;right:12px;bottom:0;width:700px;height:820px;z-index:2;display:flex;align-items:flex-end;justify-content:center}
.cover-visual img{width:650px;height:auto;filter:drop-shadow(0 30px 70px rgba(0,0,0,.5));opacity:.98;
  -webkit-mask-image:linear-gradient(90deg,transparent 0,#000 16%,#000 100%);
  mask-image:linear-gradient(90deg,transparent 0,#000 16%,#000 100%)}
.cover-visual::before{content:"";position:absolute;right:50px;bottom:130px;width:480px;height:480px;border-radius:50%;background:radial-gradient(circle,rgba(70,180,230,.18),transparent 68%);filter:blur(30px)}
.cover-chips{position:absolute;left:72px;bottom:94px;display:flex;gap:12px;z-index:4}
.cover-chips span{font-size:17px;letter-spacing:.5px;color:#d5e7f1;border:1px solid rgba(160,210,235,.25);background:rgba(8,28,44,.5);border-radius:99px;padding:10px 16px}
.cover-side{position:absolute;right:58px;top:120px;z-index:4;text-align:right;color:var(--muted);font-family:var(--num);font-size:13px;letter-spacing:2px;line-height:2}
.cover-side b{color:var(--gold);font-weight:400}
.cover::after{content:"";position:absolute;right:-140px;top:110px;width:600px;height:600px;border:1px solid rgba(120,190,225,.1);border-radius:50%;box-shadow:0 0 0 40px rgba(120,190,225,.02),0 0 0 80px rgba(120,190,225,.012)}

/* slide 2 */
.import-grid{display:grid;grid-template-columns:1.3fr .92fr;gap:28px;height:100%}
.car-frame{position:relative;border-radius:16px;overflow:hidden;border:1px solid var(--line);background:#071826}
.car-frame img{width:100%;height:100%;object-fit:cover;object-position:50% 55%;opacity:.96}
.car-frame::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(4,15,25,.02),rgba(4,15,25,.45))}
.car-frame .cap{position:absolute;left:20px;bottom:16px;z-index:3;font-size:15px;color:#d4e7f1;letter-spacing:.4px;background:rgba(4,16,27,.55);padding:7px 10px;border-radius:4px}
.car-frame .pin{position:absolute;z-index:3;width:13px;height:13px;border-radius:50%;background:var(--gold);box-shadow:0 0 0 7px rgba(226,183,107,.16),0 0 18px rgba(226,183,107,.8)}
.car-frame .pin::after{content:attr(data-label);position:absolute;left:20px;top:-9px;white-space:nowrap;font-size:15px;color:#fff;background:rgba(4,16,27,.78);border:1px solid rgba(226,183,107,.4);padding:6px 9px;border-radius:4px}
.q-stack{display:flex;flex-direction:column;gap:16px}
.qcard{flex:1;border:1px solid var(--line);border-radius:12px;background:linear-gradient(145deg,rgba(10,36,56,.74),rgba(5,20,33,.82));padding:22px 24px;position:relative}
.qcard .bar{position:absolute;left:0;top:0;bottom:0;width:3px;background:var(--red)}
.qcard .no{font-family:var(--num);font-size:15px;letter-spacing:2px;color:var(--red)}
.qcard h3{font-size:30px;margin:6px 0 6px;color:#fff;line-height:1.2}
.qcard p{font-size:23px;line-height:1.55;color:var(--soft);margin:0}

/* slide 3 */
.learn-grid{display:grid;grid-template-columns:1.42fr 1fr;gap:28px;height:100%}
.graph-card{padding:14px 16px 8px;background:linear-gradient(145deg,rgba(8,30,48,.82),rgba(4,16,28,.88))}
.graph-card svg{width:100%;height:100%;overflow:visible}
.weak-list{display:flex;flex-direction:column;gap:12px}
.weak{border:1px solid var(--line);border-radius:11px;background:rgba(7,27,44,.66);padding:14px 18px;display:flex;gap:16px;align-items:flex-start}
.weak .n{font-family:var(--num);font-size:42px;line-height:1;color:var(--red);min-width:74px}
.weak b{font-size:23px;line-height:1.35;color:#fff;display:block;margin-bottom:3px}
.weak p{font-size:19px;line-height:1.55;color:var(--muted);margin:0}
.learn-quote{font-size:15px;line-height:1.6;color:var(--dim);border-top:1px dashed var(--line);padding-top:8px;margin-top:auto}

/* slide 4 */
.compare{display:grid;grid-template-columns:1.35fr .9fr;gap:28px;height:100%}
.compare-card{padding:14px 18px;display:flex;flex-direction:column}
.compare-card .cap{display:flex;justify-content:space-between;align-items:center;font-size:17px;color:var(--muted);margin-bottom:2px}
.compare-card .cap b{color:#fff;font-size:20px}
.compare-card svg{width:100%;flex:1}
.adv{display:flex;flex-direction:column;gap:12px}
.adv .item{display:flex;gap:14px;padding:12px 16px;border:1px solid var(--line);border-radius:10px;background:rgba(7,27,44,.62)}
.adv .item b{font-family:var(--num);font-size:30px;color:var(--red);line-height:1;min-width:42px}
.adv .item h4{font-size:23px;margin:0 0 3px;color:#fff}
.adv .item p{font-size:17px;line-height:1.5;color:var(--muted);margin:0}
.car-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-top:2px}
.car-strip .c{position:relative;height:76px;border-radius:6px;overflow:hidden;border:1px solid var(--line)}
.car-strip img{width:100%;height:100%;object-fit:cover}
.car-strip span{position:absolute;left:5px;bottom:4px;font-size:11px;color:#fff;background:rgba(4,16,27,.62);padding:2px 4px;border-radius:2px}

/* slide 5 3D */
.lab-grid{display:grid;grid-template-columns:1.42fr .88fr;gap:28px;height:100%}
.lab-frame{position:relative;border:1px solid rgba(120,200,235,.25);border-radius:16px;overflow:hidden;background:#04101a;box-shadow:0 22px 60px rgba(0,0,0,.3)}
.lab-frame iframe{width:100%;height:100%;border:0;display:block}
.lab-frame .hint{position:absolute;left:18px;bottom:14px;z-index:3;font-size:15px;color:#c5deeb;background:rgba(4,16,27,.62);border:1px solid rgba(120,200,235,.22);padding:7px 10px;border-radius:4px;letter-spacing:.4px}
.lab-frame .labtag{position:absolute;left:18px;top:14px;z-index:3;font-family:var(--num);font-size:12px;letter-spacing:2px;color:var(--gold);background:rgba(4,16,27,.62);border:1px solid rgba(226,183,107,.3);padding:6px 9px;border-radius:4px}
.slide#s5 .hint{left:auto;right:18px;top:14px;bottom:auto}
.lab-copy{display:flex;flex-direction:column;justify-content:center}
.lab-copy h2{font-size:38px;line-height:1.2;margin:10px 0 12px;color:#fff}
.lab-copy h2 em{font-style:normal;color:var(--gold)}
.lab-copy p{font-size:21px;line-height:1.7;color:var(--soft);margin:0 0 16px}
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:16px}
.chips span{font-size:15px;color:#d4e7f1;border:1px solid rgba(120,200,235,.25);background:rgba(8,28,44,.6);padding:7px 10px;border-radius:99px}
.roles{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;border-top:1px solid var(--line);padding-top:14px}
.role b{display:block;font-size:17px;color:var(--gold);letter-spacing:.5px}
.role span{display:block;font-size:14px;line-height:1.5;color:var(--muted);margin-top:5px}

/* slide 6 force */
.force-grid{display:grid;grid-template-columns:1.45fr .85fr;gap:28px;height:100%}
.figure{position:relative;border:1px solid var(--line);border-radius:14px;background:linear-gradient(145deg,rgba(8,30,48,.75),rgba(4,16,28,.82));padding:8px;min-height:0}
.figure svg{width:100%;height:100%}
.force-list{display:flex;flex-direction:column;gap:12px}
.fitem{border:1px solid var(--line);border-left:3px solid var(--c);border-radius:10px;padding:13px 16px;background:rgba(7,27,44,.6)}
.fitem .tag{color:var(--c);font-size:13px}
.fitem h4{font-size:24px;margin:4px 0 3px;color:#fff}
.fitem p{font-size:18px;line-height:1.55;color:var(--muted);margin:0}
.mis{font-size:19px;line-height:1.6;color:#ffd0c8;border:1px solid rgba(225,90,75,.42);background:rgba(225,90,75,.07);border-radius:10px;padding:12px 14px;margin-top:auto}
.mis b{color:var(--red)}

/* slide 7 spring */
.damper-grid{display:grid;grid-template-columns:1.12fr .88fr;gap:28px;height:100%}
.cut-card{padding:8px;display:flex;align-items:center;justify-content:center}
.cut-card svg{width:100%;height:100%}
.duo{display:flex;flex-direction:column;gap:14px}
.duo .card{flex:1;padding:22px 24px}
.duo .k{font-family:var(--num);font-size:18px;color:var(--gold);letter-spacing:2px}
.duo h3{font-size:32px;margin:6px 0 6px;color:#fff}
.duo p{font-size:20px;line-height:1.65;color:var(--soft);margin:0}
.mini-quote{font-size:20px;line-height:1.6;color:var(--gold);border-left:2px solid var(--gold);padding-left:14px;margin-top:auto}

/* slide 8/9 */
.figure-grid{display:grid;grid-template-columns:1.5fr .8fr;gap:28px;height:100%}
.points{display:flex;flex-direction:column;gap:12px;justify-content:center}
.point{border:1px solid var(--line);border-radius:10px;padding:14px 16px;background:rgba(7,27,44,.6)}
.point b{font-size:14px;color:var(--gold);letter-spacing:1px}
.point h4{font-size:24px;margin:4px 0 4px;color:#fff}
.point p{font-size:18px;line-height:1.55;color:var(--muted);margin:0}
.big-idea{font-size:22px;line-height:1.45;color:#fff;border-left:3px solid var(--red);padding-left:14px}
.big-idea em{font-style:normal;color:var(--red)}

/* slide 10 errors */
.error-grid{display:grid;grid-template-columns:1fr 1fr;grid-template-rows:1fr 1fr;gap:16px;height:100%}
.flip{perspective:1100px;cursor:pointer;height:100%;position:relative}
.flip-inner{position:relative;width:100%;height:100%;transition:transform .65s var(--ease);transform-style:preserve-3d}
.flip.on .flip-inner{transform:rotateY(180deg)}
.face{position:absolute;inset:0;backface-visibility:hidden;border:1px solid var(--line);border-radius:12px;background:linear-gradient(145deg,rgba(10,36,56,.78),rgba(5,20,33,.86));padding:20px 22px;overflow:hidden}
.back{transform:rotateY(180deg);background:linear-gradient(145deg,rgba(15,52,78,.94),rgba(7,26,42,.96));border-color:rgba(226,183,107,.35)}
.face .no{font-family:var(--num);font-size:15px;letter-spacing:2px;color:var(--red)}
.face h3{font-size:28px;line-height:1.3;margin:7px 0 6px;color:#fff}
.face p{font-size:19px;line-height:1.55;color:var(--soft);margin:0;max-width:560px}
.face .turn{position:absolute;right:16px;bottom:10px;font-size:13px;color:var(--dim)}
.face .wm{position:absolute;right:16px;bottom:-18px;font-family:var(--num);font-size:130px;line-height:1;font-weight:700;color:rgba(120,190,225,.06);pointer-events:none}
.back .wm{color:rgba(226,183,107,.08)}
.back h3{color:var(--gold)}
.back p{color:#c7dce8}
.back .ok{font-size:14px;letter-spacing:1.5px;color:#7fe2b3;margin-bottom:6px}

/* slide 11 quiz */
.quiz-grid{display:grid;grid-template-columns:1.42fr .88fr;gap:28px;height:100%}
.quiz-copy{display:flex;flex-direction:column;justify-content:center}
.quiz-copy h2{font-size:34px;line-height:1.25;margin:0 0 12px;color:#fff}
.quiz-copy p{font-size:20px;line-height:1.7;color:var(--soft);margin:0 0 16px}
.quiz-list{display:flex;flex-direction:column;gap:8px}
.qi{display:flex;align-items:center;gap:12px;padding:9px 12px;border:1px solid var(--line);border-radius:8px;background:rgba(7,27,44,.55)}
.qi .n{width:26px;height:26px;border-radius:50%;border:1px solid rgba(226,183,107,.5);color:var(--gold);font-family:var(--num);font-size:15px;display:grid;place-items:center;flex:0 0 auto}
.qi b{font-size:19px;color:#fff}
.qi > span:last-child{font-size:14px;color:var(--muted);margin-left:auto}
.qi .n{margin-left:0}
.eval{font-size:16px;line-height:1.6;color:var(--muted);border-top:1px solid var(--line);padding-top:10px;margin-top:8px}

/* slide 12 innovation */
.innov{display:grid;grid-template-columns:1.05fr .95fr;gap:28px;height:100%}
.innov-img{position:relative;border:1px solid var(--line);border-radius:14px;overflow:hidden;background:#0b1c2d}
.innov-img img{width:100%;height:100%;object-fit:cover;opacity:.95}
.innov-img::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(4,15,25,.05),rgba(4,15,25,.6))}
.innov-img .cap{position:absolute;left:18px;bottom:16px;font-size:15px;color:#d8eaf3;z-index:2}
.innov-copy{display:flex;flex-direction:column;justify-content:center}
.innov-copy h2{font-size:34px;line-height:1.25;margin:0 0 12px;color:#fff}
.innov-copy p{font-size:20px;line-height:1.65;color:var(--soft);margin:0 0 14px}
.innov-points{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.ip{border:1px solid var(--line);border-radius:9px;padding:11px 13px;background:rgba(7,27,44,.6)}
.ip b{font-size:16px;color:var(--gold);display:block;margin-bottom:3px}
.ip span{font-size:15px;line-height:1.5;color:var(--muted)}
.pathline{display:flex;align-items:center;gap:6px;margin-top:14px;font-size:14px;color:var(--soft)}
.pathline b{font-family:var(--num);color:var(--gold);font-size:12px}
.pathline i{width:14px;height:1px;background:var(--gold)}

/* slide 13 ideology */
.ideo{display:grid;grid-template-columns:1.15fr .85fr;gap:36px;height:100%;align-items:center}
.ideo .huge{font-family:var(--num);font-size:126px;line-height:.86;color:var(--gold);letter-spacing:-3px}
.ideo .huge small{font-size:30px;letter-spacing:0;color:#d9c39e;margin-left:4px}
.ideo h2{font-size:38px;line-height:1.25;color:#fff;margin:12px 0 14px}
.ideo h2 em{font-style:normal;color:var(--gold)}
.ideo p{font-size:21px;line-height:1.8;color:var(--soft);margin:0 0 14px;max-width:720px}
.principles{display:flex;gap:10px}
.principles span{font-size:17px;color:#e3f2fa;border:1px solid rgba(226,183,107,.4);padding:8px 14px;border-radius:99px;background:rgba(226,183,107,.06)}
.photo-frame{position:relative;border:1px solid rgba(226,183,107,.4);border-radius:10px;overflow:hidden;box-shadow:0 22px 60px rgba(0,0,0,.3)}
.photo-frame img{width:100%;height:320px;object-fit:cover;display:block;filter:saturate(.9)}
.photo-frame .cap{position:absolute;left:12px;bottom:10px;font-size:13px;color:#fff;background:rgba(4,16,27,.6);padding:4px 7px;border-radius:3px}
.safety-badge{position:absolute;right:6px;bottom:-46px;border:1px solid rgba(225,90,75,.55);color:#ffb3a8;background:rgba(225,90,75,.08);padding:8px 14px;border-radius:99px;font-size:15px;letter-spacing:2px;transform:rotate(-3deg)}

/* slide 14 summary */
.sum{display:grid;grid-template-columns:1.05fr .95fr;gap:28px;height:100%}
.sum-img{position:relative;border:1px solid rgba(120,200,235,.25);border-radius:14px;overflow:hidden;background:#061522}
.sum-img img{width:100%;height:100%;object-fit:contain;mix-blend-mode:screen;
  -webkit-mask-image:linear-gradient(90deg,transparent 0,#000 14%,#000 86%,transparent 100%);
  mask-image:linear-gradient(90deg,transparent 0,#000 14%,#000 86%,transparent 100%)}
.sum-img .tag1{position:absolute;left:18px;top:18px;font-size:15px;color:var(--cyan);border:1px solid rgba(92,225,255,.3);padding:6px 9px;border-radius:4px;background:rgba(4,16,27,.55)}
.sum-copy{display:flex;flex-direction:column;gap:12px;justify-content:center}
.take{border:1px solid var(--line);border-left:3px solid var(--gold);border-radius:9px;padding:12px 15px;background:rgba(7,27,44,.6)}
.take b{font-size:13px;letter-spacing:1.5px;color:var(--gold)}
.take h4{font-size:23px;margin:3px 0 3px;color:#fff}
.take p{font-size:16px;line-height:1.55;color:var(--muted);margin:0}
.exit{border:1px dashed rgba(226,183,107,.45);border-radius:9px;padding:11px 14px;background:rgba(226,183,107,.055);font-size:16px;line-height:1.6;color:var(--soft)}
.exit b{color:var(--gold);font-size:13px;letter-spacing:1px;display:block;margin-bottom:3px}

/* slide 15 end */
.end{display:flex;align-items:center;justify-content:center;text-align:center}
.end-inner{position:relative;z-index:2}
.end h1{font-size:56px;line-height:1.2;margin:0 0 10px;color:#fff}
.end h1 em{font-style:normal;color:var(--gold)}
.end .line{width:100px;height:2px;background:var(--red);margin:24px auto}
.end p{font-size:26px;letter-spacing:4px;color:var(--soft);margin:0}
.end .meta{font-size:18px;line-height:1.9;color:#d6e6ef;letter-spacing:.5px;margin-top:20px}
.end .meta b{color:var(--gold);font-weight:400}
.end .end-logo{margin:24px auto 0;display:inline-block}

/* floating controls */
.arrow{position:fixed;top:50%;width:46px;height:46px;margin-top:-23px;z-index:90;border-radius:50%;border:1px solid rgba(120,190,225,.28);background:rgba(6,22,35,.72);color:#d9edf7;display:grid;place-items:center;cursor:pointer;font-size:22px;backdrop-filter:blur(8px);transition:.25s}
.arrow:hover{border-color:var(--gold);color:var(--gold);background:rgba(12,40,60,.85)}
.arrow:disabled{opacity:.18;cursor:default}
.arrow.prev{left:14px}.arrow.next{right:14px}
.progress{position:fixed;left:0;top:0;right:0;height:2px;z-index:100;background:rgba(255,255,255,.06)}
.progress i{display:block;height:100%;width:6.67%;background:linear-gradient(90deg,var(--gold),var(--cyan));transition:width .7s var(--ease)}
.keyhint{position:fixed;left:50%;bottom:5px;transform:translateX(-50%);z-index:80;font-size:10px;letter-spacing:1.4px;color:rgba(200,225,240,.36);font-family:var(--num);pointer-events:none;transition:opacity .8s}
.keyhint kbd{border:1px solid rgba(200,225,240,.18);border-radius:3px;padding:0 4px}

@media (max-width:900px){.arrow,.keyhint{display:none}}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}}
body.static .s-head,body.static .s-body,body.static .cover-copy,body.static .cover-visual{opacity:1!important;transform:none!important;transition:none!important}