/* Welcome video: a full-screen slide show with a narrator. The stage is 1920 x 1080 and is scaled to fit any screen. */
:root{--navy:#0f2a4a;--navy2:#1b3d68;--gold:#d2aa4a;--gold2:#b38b2d;--cream:#fff6e3;--serif:'Source Serif 4',Georgia,'Times New Roman',serif;--sans:'Source Sans 3','Segoe UI',Arial,sans-serif}
*{box-sizing:border-box}
html,body{margin:0;height:100%;background:#050d18;overflow:hidden;font-family:var(--sans)}
.screen{position:fixed;inset:0;display:grid;place-items:center;background:#050d18}
.stage{position:absolute;left:50%;top:50%;width:1920px;height:1080px;transform-origin:center;transform:translate(-50%,-50%) scale(.5);overflow:hidden;background:#0b2038;color:#fff;border-radius:0}

/* slides */
.slide{position:absolute;inset:0;opacity:0;visibility:hidden;transition:opacity .8s ease,visibility 0s .8s;background:linear-gradient(160deg,#0a1d34 0%,#12335a 100%)}
.slide.on{opacity:1;visibility:visible;transition:opacity .8s ease}
.slide::after{content:"";position:absolute;inset:0;background:radial-gradient(ellipse at 85% 0%,rgba(210,170,74,.16),transparent 55%);pointer-events:none}
.top{position:absolute;left:0;right:0;top:0;height:130px;padding:0 90px;display:flex;align-items:center;justify-content:space-between;z-index:2}
.kick{font:700 26px var(--sans);letter-spacing:.2em;text-transform:uppercase;color:var(--gold)}
.badge{width:92px;height:92px;border-radius:50%;background:#fff;display:grid;place-items:center;box-shadow:0 6px 24px rgba(0,0,0,.35)}
.badge img{width:70px;height:70px;object-fit:contain}
.body{position:absolute;left:120px;right:120px;top:150px;bottom:110px;display:flex;flex-direction:column;justify-content:center;gap:44px;z-index:1}
.body.center{align-items:center;text-align:center}

/* things that appear when the narrator reaches them */
[data-s]{opacity:0;transform:translateY(22px);transition:opacity .9s ease,transform .9s ease}
[data-s].in{opacity:1;transform:none}
.static [data-s]{opacity:1;transform:none;transition:none}

/* type */
h1,h2,h3{font-family:var(--serif);margin:0;line-height:1.15;color:#fff}
.big{font-size:104px;font-weight:700;letter-spacing:-.01em}
.mid{font-size:80px;font-weight:700}
em{font-style:normal;color:var(--gold)}
.lede{font-size:46px;margin:0;max-width:1300px;line-height:1.35;color:#e8eef7}
.lede b{color:var(--gold);font-weight:700}

/* warm opening */
.slide.warm{background:radial-gradient(ellipse at 50% 38%,#fffaf0 0%,#f8e8c6 52%,#e8c883 100%)}
.slide.warm::after{background:none}
.glow{position:absolute;border-radius:50%;filter:blur(70px);opacity:.55;animation:float 14s ease-in-out infinite}
.glow.g1{width:620px;height:620px;left:-120px;top:-80px;background:#ffe3a3}
.glow.g2{width:560px;height:560px;right:-100px;bottom:-120px;background:#f5c777;animation-delay:-5s}
.glow.g3{width:420px;height:420px;left:48%;top:56%;background:#fff2cf;animation-delay:-9s}
@keyframes float{0%,100%{transform:translate(0,0)}50%{transform:translate(40px,-30px)}}
.open-wrap{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;z-index:1}
.open-logo{width:420px;height:420px;object-fit:contain;filter:drop-shadow(0 18px 30px rgba(15,42,74,.25));opacity:0;transform:scale(.9);animation:logoIn 2.2s .4s ease forwards}
@keyframes logoIn{to{opacity:1;transform:none}}
.open-h{font-size:150px;color:var(--navy);margin-top:6px;font-weight:700}
.open-sub{font:700 34px var(--sans);letter-spacing:.32em;text-transform:uppercase;color:var(--gold2);margin:14px 0 0}
.open-rule{width:220px;height:5px;border-radius:3px;background:linear-gradient(90deg,transparent,var(--gold2),transparent);margin:34px 0 28px}
.open-by{font-size:30px;line-height:1.45;color:#3d4b60;margin:0}

/* bridge */
.bridge{display:flex;align-items:center;gap:30px;margin-top:20px}
.bcard{width:560px;padding:38px 42px;border-radius:22px;text-align:left}
.bcard small{display:block;font:700 22px var(--sans);letter-spacing:.2em;text-transform:uppercase;margin-bottom:12px}
.bcard b{font:700 46px/1.2 var(--serif)}
.bcard.from{background:rgba(255,255,255,.1);border:2px solid rgba(255,255,255,.28)}
.bcard.from small{color:#b9c8dc}
.bcard.to{background:linear-gradient(145deg,#e6c067,#c79a36);color:#10243f;box-shadow:0 0 70px rgba(210,170,74,.4)}
.bcard.to small{color:#5b4210}
.barrow{width:340px;height:110px;flex:none}
.bpath{animation:dash 3s linear infinite}
@keyframes dash{to{stroke-dashoffset:-56}}

/* three pillars and chips */
.trio{display:flex;gap:34px}
.pill{width:500px;padding:34px 30px;border-radius:22px;background:rgba(255,255,255,.09);border:2px solid rgba(255,255,255,.22);display:flex;flex-direction:column;align-items:center;gap:8px}
.pill svg{width:84px;height:84px;color:var(--gold);margin-bottom:6px}
.pill b{font:700 40px var(--serif)}
.pill span{font-size:28px;color:#c9d6e8}
.chips{display:flex;gap:22px;flex-wrap:wrap;justify-content:center}
.chips span{padding:16px 30px;border-radius:40px;background:var(--gold);color:#10243f;font:700 30px var(--sans)}

/* two-column cards */
.two{display:grid;grid-template-columns:1fr 1fr;gap:44px;width:100%}
.card{background:rgba(255,255,255,.09);border:2px solid rgba(255,255,255,.22);border-radius:24px;padding:46px 50px}
.card h3{font-size:50px;margin-bottom:22px;color:var(--gold)}
.card p{font-size:36px;line-height:1.4;margin:0;color:#e8eef7}
.card svg{width:84px;height:84px;color:var(--gold);margin-bottom:14px;display:block}
.card.dim{display:grid;place-content:center;text-align:center;background:rgba(210,170,74,.14);border-color:rgba(210,170,74,.5)}
.huge-q{font:700 54px/1.2 var(--serif)!important;color:#fff!important}
.ticks{list-style:none;margin:0;padding:0;font-size:40px;line-height:1.35}
.ticks li{padding-left:62px;position:relative;margin:14px 0}
.ticks li::before{content:"✓";position:absolute;left:0;top:-2px;width:44px;height:44px;border-radius:50%;background:var(--gold);color:#10243f;font:700 30px/44px var(--sans);text-align:center}
.card.up{border-color:rgba(210,170,74,.6)}
.card.real{border-color:rgba(160,200,255,.5)}
.card.real svg{color:#a9cdfa}.card.real h3{color:#a9cdfa}

/* what technology cannot do */
.rows{display:flex;flex-direction:column;gap:30px;width:100%}
.row{display:flex;align-items:center;gap:34px;padding:34px 44px;border-radius:22px;background:rgba(255,255,255,.09);border:2px solid rgba(255,255,255,.2)}
.row .x{flex:none;width:84px;height:84px;border-radius:50%;background:#b5382e;display:grid;place-items:center;font:700 46px var(--sans);color:#fff}
.row b{display:block;font:700 54px/1.15 var(--serif)}
.row small{display:block;font-size:32px;color:#c9d6e8;margin-top:8px;line-height:1.35}
.row em{font-style:italic}

/* statements */
.slide.statement{background:radial-gradient(ellipse at 50% 40%,#17406f 0%,#0a1d34 75%)}
.stmt{font:700 110px/1.2 var(--serif);margin:0}
.stmt.gold{color:var(--gold)}
.stmt em{font-style:italic}
.go{font:700 44px var(--sans);letter-spacing:.34em;text-transform:uppercase;color:#fff;margin:34px 0 0;padding-top:34px;border-top:3px solid var(--gold)}

/* equation banner */
.banner{display:flex;align-items:center;justify-content:center;gap:34px;font:700 52px var(--serif);padding:30px 40px;border-radius:24px;background:linear-gradient(90deg,rgba(210,170,74,.18),rgba(210,170,74,.32));border:2px solid rgba(210,170,74,.6)}
.banner i{font-style:normal;color:var(--gold);font-size:62px}
.banner .road{color:var(--gold)}

/* start and end cards */
.card-over{position:absolute;inset:0;z-index:20;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:18px;text-align:center;background:radial-gradient(ellipse at 50% 40%,#fffaf0 0%,#f8e8c6 55%,#e8c883 100%);color:var(--navy)}
.card-over[hidden]{display:none}
.card-over h1{font-size:96px;color:var(--navy)}
.card-over p{font-size:36px;margin:0;color:#3d4b60}
.card-over small{font-size:26px;color:#5a6779;margin-top:20px}
.start-logo{width:340px;height:340px;object-fit:contain;filter:drop-shadow(0 14px 24px rgba(15,42,74,.25))}
.go-btn{font:700 42px var(--sans);padding:22px 80px;border-radius:60px;border:4px solid var(--navy);background:var(--navy);color:#fff;cursor:pointer;margin-top:26px;text-decoration:none;display:inline-block}
.go-btn:hover{filter:brightness(1.2)}
.go-btn.out{background:transparent;color:var(--navy)}
.end-btns{display:flex;gap:26px}
kbd{font:700 .9em var(--sans);border:2px solid #8896a9;border-radius:6px;padding:0 10px}

/* captions and progress */
.cap{position:absolute;left:50%;bottom:64px;transform:translateX(-50%);max-width:1560px;padding:18px 36px;border-radius:14px;background:rgba(5,13,24,.82);color:#fff;font:600 38px/1.4 var(--sans);text-align:center;z-index:10;opacity:0;transition:opacity .4s}
.cap.show{opacity:1}
.slide.warm.on ~ .cap{background:rgba(15,42,74,.88)}
.bar{position:absolute;left:0;right:0;bottom:0;height:12px;display:flex;gap:6px;padding:0 6px;z-index:11}
.bar i{flex:1;background:rgba(255,255,255,.22);border-radius:3px;overflow:hidden;position:relative;cursor:pointer}
.bar i b{position:absolute;inset:0;background:var(--gold);transform:scaleX(0);transform-origin:left;transition:transform .5s linear}
.bar i.done b{transform:scaleX(1)}
.bar i.cur b{transform:scaleX(.5)}

/* controls: appear on movement */
.ctl{position:fixed;left:50%;bottom:22px;transform:translateX(-50%);display:flex;align-items:center;gap:10px;padding:10px 16px;border-radius:40px;background:rgba(5,13,24,.88);border:1px solid rgba(255,255,255,.25);z-index:50;opacity:0;pointer-events:none;transition:opacity .3s;color:#fff;font:600 14px var(--sans);max-width:calc(100% - 20px);flex-wrap:wrap;justify-content:center}
.screen.ui .ctl{opacity:1;pointer-events:auto}
.screen:not(.ui){cursor:none}
.ctl button{width:42px;height:42px;border-radius:50%;border:0;background:rgba(255,255,255,.12);color:#fff;cursor:pointer;display:grid;place-items:center;padding:0}
.ctl button:hover{background:rgba(255,255,255,.28)}
.ctl button[aria-pressed="false"]{opacity:.6}
.ctl svg{width:22px;height:22px;fill:currentColor}
.ctl .count{min-width:54px;text-align:center}
.ctl .sp{width:10px}
.ctl .sel{display:flex;align-items:center;gap:6px}
.ctl select{background:#14243b;color:#fff;border:1px solid rgba(255,255,255,.3);border-radius:6px;padding:6px 8px;font:600 14px var(--sans);max-width:200px}
#b-play .i-play,#b-play.paused .i-pause{display:none}
#b-play.paused .i-play{display:block}
#b-mute .i-mut{display:none}
#b-mute.off .i-snd{display:none}
#b-mute.off .i-mut{display:block}
.ctl button:focus-visible,.ctl select:focus-visible,.go-btn:focus-visible{outline:3px solid #ffd800;outline-offset:2px}

@media (prefers-reduced-motion:reduce){
  .slide,[data-s]{transition-duration:.01s}
  .glow,.bpath,.open-logo{animation:none}
  .open-logo{opacity:1;transform:none}
}

/* part 2 */
.chips.no span{background:rgba(255,255,255,.1);color:#e8eef7;border:2px solid rgba(255,255,255,.3);text-decoration:line-through;text-decoration-color:#e46b5f;text-decoration-thickness:4px}
.chips.no i{font-style:normal;color:#e46b5f;margin-right:14px;text-decoration:none;display:inline-block}
.flow{display:flex;align-items:center;gap:26px;margin-top:10px}
.node{width:450px;padding:34px 36px;border-radius:22px;background:rgba(255,255,255,.1);border:2px solid rgba(255,255,255,.28);text-align:left}
.node small{display:block;font:700 22px var(--sans);letter-spacing:.16em;text-transform:uppercase;color:#b9c8dc;margin-bottom:10px}
.node b{font:700 46px/1.15 var(--serif)}
.node.gold{background:linear-gradient(145deg,#e6c067,#c79a36);color:#10243f;border-color:transparent;box-shadow:0 0 70px rgba(210,170,74,.4)}
.node.gold small{color:#5b4210}
.arr{width:110px;height:40px;flex:none}
.pipe{display:flex;align-items:center;gap:22px;width:100%;margin-top:6px}
.pn{flex:1;padding:36px 30px;border-radius:22px;background:rgba(255,255,255,.1);border:2px solid rgba(255,255,255,.28);text-align:center}
.pn small{display:block;font:700 21px var(--sans);letter-spacing:.14em;text-transform:uppercase;color:#b9c8dc;margin-bottom:12px}
.pn b{font:700 44px/1.15 var(--serif)}
.pn.filt{background:rgba(210,170,74,.18);border-color:rgba(210,170,74,.7)}
.pn.filt b{color:var(--gold)}
.note{font:600 40px var(--sans);text-align:center;margin:0;color:#e8eef7}
.warn{font-size:44px;line-height:1.35;padding:30px 44px;border-radius:22px;background:rgba(181,56,46,.22);border:3px solid #e46b5f;max-width:1400px}
.warn b{color:#ffb4aa}
.three{display:grid;grid-template-columns:repeat(3,1fr);gap:36px;width:100%}
.three .card{padding:40px 38px}
.three .card h3{font-size:44px;margin:14px 0 14px}
.three .card p{font-size:32px}
.num{display:inline-grid;place-items:center;width:70px;height:70px;border-radius:50%;background:var(--gold);color:#10243f;font:700 40px var(--serif)}
.route{display:flex;gap:44px;align-items:stretch}
.stop{width:480px;padding:34px 34px;border-radius:22px;background:rgba(255,255,255,.1);border:2px solid rgba(255,255,255,.28);display:flex;align-items:center;gap:24px;text-align:left;position:relative}
.stop+.stop::before{content:"";position:absolute;left:-44px;top:50%;width:44px;border-top:5px dashed var(--gold)}
.stop b{flex:none;display:grid;place-items:center;width:64px;height:64px;border-radius:50%;background:var(--gold);color:#10243f;font:700 36px var(--serif)}
.stop span{font:700 34px/1.25 var(--serif)}
.strike{font:600 44px var(--sans);margin:0;color:#c9d6e8;text-decoration:line-through;text-decoration-color:#e46b5f;text-decoration-thickness:4px}

/* part 3 */
.open-h.sm{font-size:110px}
.stmt.sm{font-size:88px}
.smart{max-width:1360px;padding:44px 60px;border-radius:26px;background:linear-gradient(145deg,#e6c067,#c79a36);color:#10243f;box-shadow:0 0 70px rgba(210,170,74,.35)}
.smart h3{font-size:92px;color:#10243f;margin:0 0 16px}
.smart p{margin:0;font-size:40px;line-height:1.35;color:#10243f}
.card.no{border-color:#e46b5f}
.card.no h3{color:#ffb4aa}
.ticks.crossed li::before{content:"✕";background:#b5382e;color:#fff}
.three .ticks{font-size:34px}
.three .ticks li{padding-left:56px;margin:12px 0}
.three .ticks li::before{width:38px;height:38px;font-size:26px;line-height:38px}
.carry{max-width:1360px;padding:36px 54px;border-radius:24px;background:rgba(210,170,74,.16);border:3px solid var(--gold);font:600 46px/1.35 var(--serif);text-align:center}

/* the hidden attribute must win over display rules such as the button style */
[hidden]{display:none !important}

/* part 4 */
.four{display:grid;grid-template-columns:repeat(4,1fr);gap:28px;width:100%}
.four .card{padding:36px 30px}
.four .card h3{font-size:40px;margin-bottom:14px}
.four .card p{font-size:30px}