:root{color-scheme:light;--ink:#17251d;--muted:#5b685f;--paper:#f5f5ed;--green:#1c4933;--lime:#d5ec98;--rule:#d7dcd0}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.65 Arial,Helvetica,sans-serif}a{color:inherit;text-decoration:none}button{font:inherit}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #688d20;outline-offset:5px}.skip{position:absolute;top:-100px;background:white;padding:12px;z-index:5}.skip:focus{top:0}.notice{background:#132b20;color:#e0e8d9;text-align:center;font-size:11px;letter-spacing:.06em;padding:8px 16px}header,main,footer{max-width:1440px;margin:auto}header{height:108px;display:flex;align-items:center;justify-content:space-between;padding:0 6%;gap:24px;border-bottom:1px solid var(--rule)}.brand{font-size:30px;font-weight:700;letter-spacing:-1.5px;display:flex;align-items:center;gap:8px;white-space:nowrap}.brand-sub{font-size:14px;font-weight:400;letter-spacing:-.2px;margin-left:3px}.mark{font-size:40px;color:var(--green);line-height:1}nav{display:flex;gap:28px;font-size:13px}nav a:hover,.text-link:hover,footer a:hover{text-decoration:underline}.source-top{font-size:12px;border:1px solid #a7b2a4;border-radius:30px;padding:10px 17px;white-space:nowrap}.hero{padding:78px 6% 68px;display:grid;grid-template-columns:1.08fr 1fr;gap:45px;align-items:center}.eyebrow{font:10px/1.6 'Courier New',monospace;letter-spacing:.13em;font-weight:700}.dot{display:inline-block;width:7px;height:7px;background:#8dad45;border-radius:50%;margin-right:7px}h1,h2,h3,p{margin-top:0}h1{font-size:clamp(48px,5.35vw,78px);letter-spacing:-.065em;line-height:1.05;font-weight:500;margin:27px 0}h1 em{font:italic .77em/1.2 Georgia,serif;letter-spacing:-.055em}.lede{font-size:16px;line-height:1.8;max-width:480px;color:var(--muted)}.actions{display:flex;align-items:center;gap:24px;margin:30px 0 18px}.button{display:inline-flex;justify-content:space-between;align-items:center;gap:25px;padding:15px 22px;min-height:52px;border-radius:5px;font-size:13px;font-weight:600}.primary{background:var(--green);color:#fff}.primary:hover{background:#103723}.text-link{font-size:13px;font-weight:600;display:inline-block;min-height:44px;line-height:44px}.micro{font-size:11px;color:var(--muted)}.visual{background:#e8ebdb;min-height:460px;border-radius:3px;padding:24px 25px 18px;position:relative;overflow:hidden;display:flex;flex-direction:column;justify-content:space-between;background-image:linear-gradient(#52674409 1px,transparent 1px),linear-gradient(90deg,#52674409 1px,transparent 1px);background-size:25px 25px}.visual-label,.visual-bottom{display:flex;justify-content:space-between;align-items:center;font:9px 'Courier New',monospace;letter-spacing:.08em}.visual p{text-align:center;font:italic 16px Georgia,serif;margin:14px 0 0;color:#53624c}.line{height:1px;background:#98a48a;flex:1;margin:0 15px}.orb{width:290px;height:290px;margin:22px auto 30px;border-radius:50%;background:repeating-radial-gradient(ellipse at 35% 30%,transparent 0 3px,#162f20b0 3.5px 4px,transparent 4.5px 7px),radial-gradient(circle at 30% 20%,#eaffb1 0%,#b9d875 35%,#6a8a42 65%,#163c2b 95%);box-shadow:20px 30px 40px #253e262b,inset -25px -12px 40px #112a354a;transform:rotate(-24deg);position:relative}.orb:before{content:'';position:absolute;inset:17% -9%;border:1px solid #46633555;border-radius:50%;transform:rotate(-20deg)}.orb-core{position:absolute;inset:5%;border-radius:50%;background:repeating-linear-gradient(12deg,transparent 0 6px,#d9f89960 7px,transparent 8px 10px);mix-blend-mode:soft-light}.status-strip{margin:0 6%;padding:25px 0;border-top:1px solid var(--rule);border-bottom:1px solid var(--rule);display:grid;grid-template-columns:1.25fr 1fr 1fr auto;align-items:center;gap:25px}.status-strip>div{display:flex;flex-direction:column;gap:7px;font-size:11px;color:var(--muted)}.status-strip strong{font-size:13px;color:var(--ink);font-weight:500}.status-strip>a{font-size:11px;border-bottom:1px solid #8b9884}.section{padding:83px 6%;border-bottom:1px solid var(--rule)}.intro{display:grid;grid-template-columns:1fr 1fr;gap:70px}h2{font-weight:500;letter-spacing:-.05em;font-size:44px;line-height:1.12;margin:18px 0 25px}.intro p:not(.big-copy){font-size:14px;color:var(--muted)}.big-copy{font-size:24px;line-height:1.5;letter-spacing:-.02em}.duplex{background:#142e22;color:#f1f4e9;display:grid;grid-template-columns:1fr 1.15fr;gap:70px;align-items:center}.duplex h2{font-size:39px}.duplex p{font-size:13px;color:#b8c8b7;max-width:350px}.duplex .micro{font-size:10px}.toggle{display:flex;border:1px solid #607263;width:max-content;border-radius:5px;padding:4px;margin:25px 0 14px}.toggle button{border:0;border-radius:3px;padding:8px 15px;background:transparent;color:#d6e0cd;font-size:12px;min-height:40px;cursor:pointer}.toggle button[aria-pressed=true]{background:#d3e99d;color:#132b20}.track-label{display:flex;justify-content:space-between;font:10px 'Courier New',monospace;margin:24px 0 13px;color:#d7e3c7}.track-label span{color:#91a88f;font-size:9px}.track{height:56px;position:relative;border-bottom:1px solid #7e98704d;background:repeating-linear-gradient(90deg,transparent 0 calc(8.33% - 1px),#ffffff08 calc(8.33% - 1px) 8.33%)}.track i{position:absolute;top:6px;height:35px;border-radius:4px;background:repeating-linear-gradient(90deg,#c9e88c 0 2px,transparent 2px 5px);transition:left .5s,width .5s}.human i:nth-child(1){left:0;width:33%}.human i:nth-child(2){left:45%;width:28%}.human i:nth-child(3){left:85%;width:15%}.model i{background:repeating-linear-gradient(90deg,#76b59a 0 2px,transparent 2px 5px)}.model i:nth-child(1){left:23%;width:29%}.model i:nth-child(2){left:62%;width:22%}.model i:nth-child(3){left:89%;width:11%}.turns .human i:nth-child(1){width:23%}.turns .human i:nth-child(2){left:50%;width:15%}.turns .human i:nth-child(3){left:85%;width:6%}.turns .model i:nth-child(1){left:26%;width:20%}.turns .model i:nth-child(2){left:68%;width:13%}.turns .model i:nth-child(3){left:94%;width:6%}.time-axis{display:flex;justify-content:space-between;font:8px 'Courier New',monospace;color:#a7baa0;margin:15px 0 30px}.timeline p{font-size:11px;max-width:none}.section-title{display:flex;justify-content:space-between;align-items:center}.section-title>p{font-size:13px;color:var(--muted)}.card-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:0;margin-top:25px;border:1px solid var(--rule)}.guide-card{display:block;padding:26px 22px;border-right:1px solid var(--rule)}.guide-card:last-child{border:0}.guide-card:hover{background:#e9eddc}.guide-card .eyebrow{font-size:9px;color:#64705b}.guide-card h3{font-size:21px;line-height:1.3;letter-spacing:-.04em;font-weight:500;margin:33px 0 13px;min-height:55px}.guide-card h3 span{float:right;font-size:17px}.guide-card p{font-size:12px;color:var(--muted);min-height:50px}.read{font-size:11px;font-weight:600;display:block;margin-top:25px}.source-note{text-align:center;background:#e7ecdb}.source-note p{max-width:550px;margin:0 auto 28px;color:var(--muted);font-size:14px}.source-note h2{margin:20px 0}.faq{display:grid;grid-template-columns:1fr 1.3fr;gap:60px}details{border-bottom:1px solid var(--rule);padding:0 0 18px;margin-bottom:18px}summary{cursor:pointer;font-size:14px;padding:8px 0;min-height:44px}details p{font-size:13px;color:var(--muted);padding:12px 0 0}.article{max-width:910px;padding:50px 6% 85px;margin:auto}.back{display:inline-block;font-size:12px;margin-bottom:45px;min-height:44px}.article h1{font-size:58px;margin-top:20px}.article-lede{font-size:20px;color:var(--muted);margin-bottom:50px;line-height:1.6}.article-body h2{font-size:28px;margin:36px 0 18px}.article-body p{font-size:16px;color:#4b5b4f}.reference{border-left:3px solid #617d3e;padding:25px;background:#e8eddd;margin:40px 0}.reference p{font-size:13px;margin:10px 0}.reference a{font-size:14px;text-decoration:underline}.related{display:grid;gap:12px}.related a{font-size:14px;text-decoration:underline;min-height:35px}footer{padding:50px 6% 30px;display:grid;grid-template-columns:1fr 1fr;gap:30px}.foot-brand{font-size:23px;font-weight:600;letter-spacing:-1px}.foot-brand p{font-size:12px;color:var(--muted);font-weight:400;letter-spacing:0;margin-top:7px}footer>div:nth-child(2){display:flex;gap:25px;justify-content:flex-end;font-size:11px;align-items:flex-start;padding-top:10px}footer a{min-height:44px}.fine{grid-column:1/-1;border-top:1px solid var(--rule);padding-top:22px;font-size:10px;color:var(--muted);line-height:1.8}@media(min-width:1440px){h1{font-size:78px}}@media(max-width:1050px){header{gap:14px}nav{gap:15px}.source-top{display:none}.hero{gap:25px}.visual{min-height:400px}.orb{width:240px;height:240px}.actions{flex-wrap:wrap;gap:8px}h2{font-size:38px}.card-grid{grid-template-columns:repeat(2,1fr)}.guide-card:nth-child(2){border-right:0}.guide-card:nth-child(-n+2){border-bottom:1px solid var(--rule)}.duplex{gap:35px}}@media(max-width:700px){header{height:auto;min-height:110px;padding:16px 6%;flex-wrap:wrap;gap:14px}.brand{font-size:28px}.brand-sub{font-size:12px}nav{width:100%;justify-content:space-between;gap:10px;font-size:11px}nav a{min-height:32px}.notice{font-size:9px}.hero{grid-template-columns:1fr;padding-top:43px;gap:34px}h1{font-size:58px;max-width:500px}.lede{font-size:14px}.visual{min-height:350px}.orb{width:230px;height:230px;margin:12px auto 22px}.visual-label{font-size:8px}.visual p{font-size:14px}.status-strip{grid-template-columns:1fr 1fr;gap:24px}.status-strip>a{justify-self:start}.section{padding:55px 6%}.intro,.duplex,.faq{grid-template-columns:1fr;gap:25px}h2{font-size:38px}.big-copy{font-size:21px}.section-title{align-items:flex-start;gap:15px}.section-title>p{font-size:11px}.section-title h2{font-size:33px}.guide-card{padding:21px 16px}.guide-card h3{font-size:19px}.guide-card p{min-height:65px}.source-note h2{font-size:35px}.article h1{font-size:44px}.article-lede{font-size:18px}.article{padding-top:30px}.article-body p{font-size:15px}footer{grid-template-columns:1fr;gap:15px}footer>div:nth-child(2){justify-content:flex-start}.fine{grid-column:auto}.time-axis{font-size:7px}}@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}
/* Audit improvements: clearer tasks, legible metadata and compact article navigation. */
nav a[aria-current=page]{text-decoration:underline;text-underline-offset:7px;font-weight:700}.hero{padding-top:48px;padding-bottom:42px;grid-template-columns:1.3fr 1fr}.hero h1{font-size:clamp(48px,4.8vw,68px)}.hero .visual{min-height:360px}.hero .orb{width:220px;height:220px;margin:10px auto 20px}.hero-status{font-size:13px;line-height:1.8;padding:12px 14px;background:#e7ecdb;border-left:3px solid #64833d;max-width:520px}.micro{font-size:12px}.micro a{text-decoration:underline}.eyebrow{font-size:11px}.article{padding-top:30px}.back{margin-bottom:20px}.article h1{font-size:clamp(36px,4vw,54px)}.article-lede{margin-bottom:24px}.article-toc{display:flex;flex-wrap:wrap;gap:8px 18px;margin:25px 0;padding:16px 0;border-block:1px solid var(--rule);width:auto}.article-toc a{font-size:13px;min-height:32px;line-height:1.4;display:flex;align-items:center;text-decoration:underline}.table-scroll{overflow-x:auto;margin:28px 0;border:1px solid var(--rule);border-radius:5px}.table-scroll:focus-visible{outline:3px solid #688d20}table{width:100%;border-collapse:collapse;font-size:13px;line-height:1.6}caption{text-align:left;padding:14px 16px;font-size:12px;color:var(--muted);background:#e8eddf}th,td{padding:15px;text-align:left;vertical-align:top;border-top:1px solid var(--rule)}thead{background:#edf0e5}th{font-weight:600}td{color:#4b5b4f}.citation{display:inline-block;font-size:12px;min-height:32px;text-decoration:underline;color:var(--green)}.demo-link{margin:0 0 10px}.article-body section{scroll-margin-top:25px}.article-body a:hover{text-decoration:underline}footer>div:nth-child(2){flex-wrap:wrap;gap:12px 20px}.notice{font-size:12px}.source-top{min-height:44px}.visual-label,.visual-bottom{font-size:10px}.track-label,.track-label span{font-size:11px}.time-axis{font-size:10px}.guide-card .eyebrow{font-size:11px}.guide-card p,.read{font-size:13px}.fine{font-size:12px}
@media(max-width:700px){header{padding-top:12px;padding-bottom:8px}nav{flex-wrap:wrap;gap:0 16px;justify-content:flex-start}nav a{font-size:13px;min-height:44px;display:flex;align-items:center}.hero{grid-template-columns:1fr;padding-top:30px;gap:20px}.hero h1{font-size:48px}.hero .visual{min-height:250px}.hero .orb{width:150px;height:150px;margin:10px auto}.hero .visual p{margin-top:8px}.hero-status{font-size:13px}.section{padding-top:40px;padding-bottom:40px}.notice{font-size:11px}.article h1{font-size:38px;overflow-wrap:break-word}.article-toc a{min-height:44px}.table-scroll{margin:20px 0}th,td{padding:11px 9px;font-size:12px}.table-scroll table{min-width:0}footer a{font-size:12px}.time-axis{font-size:8px}.track-label span{font-size:10px}.guide-card{padding:20px 14px}.guide-card h3{font-size:19px}.guide-card p{min-height:70px}}
.editorial-note{font-size:12px;color:var(--muted);line-height:1.8;margin:20px 0}.editorial-note a{text-decoration:underline}.section-title h2{max-width:650px}.guides .section-title{gap:24px}@media(max-width:700px){.guides .section-title{display:block}.guides h2{font-size:32px}}

/* Original recording players */
html{scroll-behavior:smooth}.listening{scroll-margin-top:24px}.demo-player{margin:24px 0;padding:24px;border:1px solid var(--line,#d6ddd4);border-radius:16px;background:#f0f3ed}.demo-player audio{display:block;width:100%;min-height:54px}.demo-player .micro{margin:12px 0 0}.demo-player .audio-error{color:#8a3023;font-size:14px}.demo-player [hidden]{display:none}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

.listening-lede{max-width:760px}.listening-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px;margin:32px 0}.listening-card{min-width:0;padding:28px;border:1px solid #d6ddd4;border-radius:18px;background:#f8faf5}.demo-meta{display:flex;justify-content:space-between;gap:12px;font-size:11px;letter-spacing:.06em;color:#526257}.listening-card h3{font-size:26px;line-height:1.2;margin:20px 0 14px}.listening-card .demo-player{padding:16px;margin:20px 0}.listening-card details{border-top:1px solid #d6ddd4;padding-top:16px}.listening-card summary{cursor:pointer;font-size:14px}.listening-card details p{font-size:14px;line-height:1.7}@media(max-width:700px){.listening-grid{grid-template-columns:1fr;gap:18px}.listening-card{padding:20px}.listening-card h3{font-size:24px}.demo-meta{font-size:10px}}

/* Conversation waveform player: real per-speaker amplitude data. */
.listening-grid{grid-template-columns:1fr}.listening-card{padding:32px}.waveform-player{background:#0d0f0e!important;border:0!important;padding:28px!important;color:#f5f5f0;--progress:0%}.wave-ui[hidden],.waveform-player audio[hidden]{display:none}.wave-stage{position:relative;display:grid;gap:12px}.wave-lane{display:flex;align-items:center;gap:22px;background:#202321;border:1px solid #2e322e;border-radius:28px;padding:18px 20px}.wave-lane:nth-child(2){background:#161916}.wave-label{flex:0 0 58px;font-size:10px;letter-spacing:.12em;color:#d2ddca}.wave-lane:nth-child(2) .wave-label{color:#d0f178}.wave-lane svg{width:100%;height:70px;min-width:0;fill:#6d746c}.wave-lane:nth-child(2) svg{fill:#a7b28e}.wave-cursor{position:absolute;top:0;bottom:0;left:calc(100px + (100% - 122px)*var(--fraction,0));display:none}.wave-stage:after{content:'';position:absolute;left:calc(100px + (100% - 122px)*var(--fraction,0));top:0;bottom:0;width:2px;background:#e7efdf;pointer-events:none}.seek-label{display:block;font-size:0;margin:10px 0 14px}.wave-seek{width:100%;height:18px;cursor:pointer;accent-color:#d0f178;margin:0}.cue-list{display:flex;gap:8px;flex-wrap:wrap;margin:4px 0 26px}.cue{background:#d0f178;color:#151a0d;border:0;border-radius:100px;padding:9px 13px;font-size:12px;cursor:pointer;display:flex;gap:9px;align-items:center}.cue span{font-size:10px;opacity:.65}.cue:hover,.cue.active{background:#ebffa8;box-shadow:0 0 0 2px #d0f17866}.player-controls{display:flex;align-items:center;gap:16px}.play-toggle{width:52px;height:52px;border:0;border-radius:50%;background:#f2f0f5;color:#181a18;font-size:21px;cursor:pointer;flex:none}.player-time{font-variant-numeric:tabular-nums;font-size:17px;display:block}.player-note{display:block;font-size:12px;color:#a5aaa1;margin-top:4px}.play-speed{margin-left:auto;background:transparent;border:1px solid #58614f;color:#e6eddf;border-radius:16px;padding:7px 12px;cursor:pointer}.audio-download{color:#edf2e8!important;font-size:25px;line-height:1;width:42px;height:42px;display:grid;place-items:center;background:#272d25;border-radius:50%;text-decoration:none}.waveform-player :focus-visible{outline:3px solid #d0f178;outline-offset:4px}.demo-strengths{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin:28px 0 36px}.demo-strengths div{border-top:2px solid #749155;padding-top:16px}.demo-strengths strong{display:block;font-size:18px;margin-bottom:8px}.demo-strengths span{font-size:13px;line-height:1.6;display:block;color:#526257}.article .waveform-player{margin:24px 0 36px}@media(max-width:700px){.listening-card{padding:20px}.waveform-player{padding:18px 12px!important}.wave-lane{padding:12px 10px;gap:10px;border-radius:18px}.wave-label{flex-basis:42px;font-size:8px}.wave-lane svg{height:48px}.wave-stage:after{left:calc(62px + (100% - 74px)*var(--fraction,0))}.cue{padding:8px 10px;font-size:11px}.cue-list{gap:7px;margin-bottom:20px}.demo-strengths{grid-template-columns:1fr;gap:16px}.player-controls{gap:10px}.player-time{font-size:15px}.play-toggle{width:44px;height:44px}}

.extended-library{display:grid;gap:28px;margin-top:28px}.extended-recording{padding-top:20px;border-top:1px solid #cdd5c8;min-width:0}.extended-recording h3{font-size:25px;line-height:1.3}.more-recordings{margin:32px 0;padding:24px;border:1px solid #cdd5c8;border-radius:18px}.more-recordings>summary{font-size:20px;cursor:pointer;font-weight:600}.ai-pair-note{font-size:13px!important;line-height:1.6;color:#526257}.cue-list:empty{display:none}.wave-label{overflow-wrap:anywhere}.extended-recording .waveform-player{margin:20px 0}@media(max-width:700px){.more-recordings{padding:14px}.more-recordings>summary{font-size:17px}.extended-recording h3{font-size:22px}}

/* Small-screen layout and touch targets. */
.hero>*,.intro>*,.duplex>*,.faq>*,.section-title>*,.player-controls>*{min-width:0}.article-body,.listening-card,.extended-recording{overflow-wrap:anywhere}.cue,.play-speed,.audio-download{min-height:44px}.audio-download{flex-shrink:0}.wave-seek{height:32px}.demo-player .audio-error{color:#ffc6b9}.player-controls{display:grid;grid-template-columns:52px minmax(0,1fr)52px 44px}.play-speed{margin-left:0;padding:7px 5px}.player-time{white-space:nowrap}.demo-meta{flex-wrap:wrap}.demo-meta>span:last-child{white-space:nowrap}.table-scroll table{min-width:440px}.table-scroll{max-width:100%}.wave-lane{overflow:hidden}.article-toc{max-width:100%}.notice{overflow-wrap:break-word}
@media(max-width:700px){.hero h1{font-size:clamp(38px,11vw,48px)}.visual-label{gap:10px}.section-title{flex-wrap:wrap}.more-recordings{padding:14px 10px}.listening-card{padding:20px 14px}.waveform-player{padding:18px 10px!important}.player-controls{grid-template-columns:44px minmax(0,1fr)40px 40px;gap:6px}.play-speed,.audio-download{width:40px}.player-time{font-size:13px}.player-note{font-size:11px;line-height:1.4}.wave-label{font-size:9px}.cue{font-size:12px}.cue span{font-size:11px}.guide-card p{min-height:0}.guide-card h3{min-height:0}.guide-card{display:flex;flex-direction:column}.guide-card .read{margin-top:auto;padding-top:15px}.time-axis{gap:7px}.track-label{gap:10px}.track-label span{text-align:right}}
@media(max-width:380px){.player-controls{grid-template-columns:40px minmax(0,1fr)36px 36px;gap:4px}.play-toggle{width:40px;height:44px}.play-speed,.audio-download{width:36px}.player-time{font-size:12px}.player-note{font-size:10px}.wave-label{flex-basis:34px;font-size:8px}.wave-lane{gap:7px;padding-inline:8px}.wave-stage:after{left:calc(50px + (100% - 60px)*var(--fraction,0))}.card-grid{grid-template-columns:1fr}.guide-card{border-right:0;border-bottom:1px solid var(--rule)}.guide-card:last-child{border-bottom:0}.guide-card h3{margin-top:15px}.guide-card p{margin-bottom:8px}footer>div:nth-child(2){gap:10px 16px}}

.wave-label{white-space:nowrap;letter-spacing:.04em}@media(max-width:380px){.wave-label{font-size:8px}}