@charset "UTF-8";
:root{--paper:#f8f7f2;--ink:#252523;--muted:#73756c;--line:#e3e4da;--lime:#e2f48a;--purple:#dabcF1;--mint:#dcead4;--white:#fff;--serif:Georgia,'Times New Roman','Songti SC',serif;--sans:-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif;--max:1200px}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;color:var(--ink);background:var(--paper);font-family:var(--sans);font-size:16px;line-height:1.65;-webkit-font-smoothing:antialiased}button,a{-webkit-tap-highlight-color:transparent}button{font:inherit;color:inherit}button,a{touch-action:manipulation}button{cursor:pointer}a{color:inherit;text-decoration:none}img{display:block;max-width:100%;height:auto}button:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #786293;outline-offset:5px}::selection{background:var(--lime);color:var(--ink)}.container{width:min(var(--max),calc(100% - 80px));margin-inline:auto}.skip-link{position:fixed;top:-100px;left:20px;background:var(--ink);color:white;padding:12px 20px;z-index:100}.skip-link:focus{top:15px}.site-header{position:sticky;top:0;z-index:20;background:#f8f7f2ee;backdrop-filter:blur(16px);border-bottom:1px solid #2525230a}.header-inner{display:flex;align-items:center;justify-content:space-between;gap:28px;min-height:92px}.brand{display:inline-flex;align-items:center;gap:10px;flex-shrink:0}.brand img{width:39px;height:39px;border-radius:12px}.wordmark{font-size:24px;font-weight:750;letter-spacing:-1.2px}.nav-links{display:flex;gap:32px;align-items:center;font-size:13px;color:#56594f}.nav-links a:hover,.footer-links a:hover{color:var(--ink);text-decoration:underline;text-underline-offset:5px}.language-picker{display:flex;gap:3px;padding:4px;border:1px solid #dfe1d5;border-radius:30px;flex-shrink:0}.language-picker button{background:none;border:0;border-radius:20px;font-size:12px;min-width:48px;min-height:32px;padding:5px 11px}.language-picker button[aria-pressed=true]{background:var(--ink);color:var(--paper)}.eyebrow{font-family:var(--sans);font-size:10px;font-weight:650;letter-spacing:2.5px;line-height:1.5;color:#656b58;text-transform:uppercase}.hero{display:grid;grid-template-columns:.95fr 1.05fr;gap:8px;align-items:center;padding-top:40px;padding-bottom:35px;min-height:640px}.hero-copy{position:relative;z-index:2;padding-bottom:20px}.hero h1{font-size:clamp(52px,5.65vw,80px);font-weight:500;line-height:1.07;letter-spacing:-4px;margin:27px 0 25px}.serif{font-family:var(--serif);font-style:italic;font-weight:400}.hero h1 .serif{color:#6c7d41}.hero-description{font-size:16px;line-height:1.85;color:var(--muted);max-width:415px;margin:0 0 29px}.button{display:inline-flex;align-items:center;justify-content:center;gap:22px;border:1px solid transparent;background:var(--ink);color:var(--paper);font-size:13px;font-weight:600;padding:15px 23px;border-radius:30px;min-height:50px;transition:transform .2s,background .2s}.button:hover{transform:translateY(-2px);background:#3d4234}.button svg,.text-link svg{width:17px;height:17px;flex-shrink:0}.platform-note{font-size:10px;color:var(--muted);margin:17px 0 0;letter-spacing:.15px}.hero-visual{position:relative;min-width:0;width:100%;max-width:500px;margin-left:auto}.island-scene{position:relative;aspect-ratio:1;margin-top:-38px}.island-scene:before{content:'';position:absolute;inset:10% 4% 12%;border-radius:50%;background:radial-gradient(ellipse,#e6edc9 5%,#ecefdc 50%,#f8f7f200 73%)}.island-art{position:absolute;inset:0;width:100%;height:100%;object-fit:contain;filter:drop-shadow(0 30px 28px #6b805011);pointer-events:none}.orbit{position:absolute;border:1px dashed #aab79260;border-radius:50%;width:88%;height:70%;top:15%;left:7%;transform:rotate(-20deg);pointer-events:none}.scene-target{position:absolute;z-index:2;display:grid;place-items:center;width:40px;height:40px;background:#fff9;border:1px solid #fff;border-radius:50%;box-shadow:0 3px 12px #35482712;transform:translate(-50%,-50%);transition:background .2s,box-shadow .2s}.scene-target:before{content:'+';font-size:23px;font-weight:300;line-height:1}.scene-target:hover{background:var(--lime);box-shadow:0 0 0 6px #fff6}.scene-target.is-learned{background:var(--lime);border-color:#b7cc64}.scene-target.is-learned:before{content:'✓';font-size:19px}.scene-target.is-wrong{animation:shake .35s}.floating-note{position:absolute;top:12%;right:0;background:#fffdf9;border:1px solid #ececdf;border-radius:16px;padding:12px 18px;font-size:11px;transform:rotate(7deg);box-shadow:0 12px 28px #464b2910;z-index:3}.floating-note:before{content:'✳';font-size:19px;margin-right:7px;color:#738449}.demo-panel{position:relative;z-index:3;width:90%;margin:-65px auto 0;padding:18px 21px;background:#ffffffd9;backdrop-filter:blur(18px);border:1px solid #fff;border-radius:22px;box-shadow:0 12px 35px #263b1f08}.demo-topline{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-bottom:12px}.demo-count{font-size:11px;font-variant-numeric:tabular-nums;color:#7a806d}.word-chips{display:flex;gap:9px}.word-chip{border:1px solid #e4e6dc;background:#f9faf5;padding:7px 17px;border-radius:12px;font-size:13px;min-height:39px;flex:1;transition:background .2s,transform .2s}.word-chip:hover:not(:disabled){transform:translateY(-2px);background:#edf2dc}.word-chip.is-selected{background:var(--ink);color:#fff;border-color:var(--ink)}.word-chip.is-learned{background:#e9f2ca;border-color:#d4e3b5;color:#586c32;text-decoration:line-through;cursor:default}.demo-bottom{display:flex;gap:12px;align-items:center;justify-content:space-between;min-height:36px;padding-top:7px}.demo-status{font-size:10px;color:#6e7663;line-height:1.5;margin:0}.reset-demo{flex-shrink:0;background:none;border:0;font-size:10px;color:var(--muted);text-decoration:underline;text-underline-offset:3px;padding:5px 0}.demo-caption{font-size:9px;text-align:center;color:#909487;margin:15px 6px 0}.principles{display:flex;justify-content:space-between;gap:25px;padding:30px 20px;border-block:1px solid var(--line);font-size:13px;color:#5b6350}.principle{display:flex;align-items:center;gap:11px}.principle .symbol{font-size:20px;color:#778656}.app-section{padding:112px 0 105px}.section-heading{max-width:700px;margin-bottom:50px}.section-heading h2,.approach h2,.privacy-banner h2,.faq-heading h2{font-size:clamp(38px,4.3vw,59px);font-weight:450;line-height:1.16;letter-spacing:-2.3px;margin:21px 0 22px}.section-heading p,.approach-intro{max-width:575px;font-size:15px;color:var(--muted);line-height:1.9}.app-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}.app-feature{min-width:0}.feature-copy{padding:0 7px;min-height:170px}.feature-label{font-size:10px;font-weight:600;letter-spacing:1.5px;color:#6f7664}.feature-copy h3{font-size:22px;letter-spacing:-.65px;font-weight:550;margin:13px 0 12px}.feature-copy p{font-size:13px;line-height:1.8;color:var(--muted);max-width:320px;margin:0}.phone-stage{border-radius:32px;padding:34px 35px 0;height:540px;overflow:hidden;display:flex;justify-content:center;align-items:flex-start}.phone-stage.lime{background:#e7edce}.phone-stage.lavender{background:#ebe0f3}.phone-stage.peach{background:#f1e5d8}.phone{width:100%;max-width:242px;border:5px solid #272b24;border-radius:33px;background:var(--paper);box-shadow:0 18px 40px #25252324;overflow:hidden;flex-shrink:0}.phone img{width:100%;border-radius:26px}.screenshot-note{font-size:10px;color:#8b8f82;margin:20px 5px 0}.approach{display:grid;grid-template-columns:1fr 1fr;gap:90px;padding:78px 0 102px;border-top:1px solid var(--line)}.approach-copy{padding-top:10px}.approach h2{margin-bottom:25px}.approach-list{padding-top:15px}.approach-item{display:flex;gap:20px;padding:25px 0;border-bottom:1px solid var(--line)}.step-number{display:grid;place-items:center;width:38px;height:38px;flex-shrink:0;background:#e9eddd;border-radius:50%;font-size:12px;color:#657145}.approach-item:nth-child(2) .step-number{background:#e8ddf0;color:#7d6289}.approach-item:nth-child(3) .step-number{background:#f1e3d4;color:#937c60}.approach-item h3{font-size:17px;font-weight:550;line-height:1.5;margin:3px 0 9px}.approach-item p{font-size:13px;color:var(--muted);line-height:1.85;margin:0;max-width:390px}.privacy-banner{position:relative;display:grid;grid-template-columns:1.1fr .9fr;gap:50px;align-items:center;padding:58px 66px;background:#e8eddb;border-radius:34px;overflow:hidden}.privacy-banner h2{font-size:44px;white-space:pre-line;margin:15px 0 22px}.privacy-banner p{max-width:470px;font-size:14px;line-height:1.9;color:#687157}.text-link{display:inline-flex;align-items:center;gap:16px;font-size:12px;font-weight:550;min-height:44px;text-decoration:underline;text-underline-offset:5px}.privacy-art{position:relative;display:flex;align-items:center;justify-content:center;min-height:270px}.privacy-art:before,.privacy-art:after{content:'';position:absolute;border:1px solid #fff9;border-radius:50%;width:240px;height:240px;transform:rotate(-15deg)}.privacy-art:after{width:290px;height:180px;transform:rotate(28deg)}.privacy-mark{display:grid;place-items:center;background:#f8f9f0bf;width:124px;height:145px;border-radius:38px;transform:rotate(9deg);box-shadow:0 12px 25px #5f754411;z-index:1}.privacy-mark svg{width:52px;height:52px;stroke:#63744d;stroke-width:1.2;fill:none}.privacy-tag{position:absolute;z-index:2;bottom:16px;left:50%;transform:translateX(-50%) rotate(-5deg);background:#fffdf8;padding:10px 19px;border-radius:9px;font-size:11px;white-space:nowrap;box-shadow:0 8px 15px #5f754411}.faq-section{display:grid;grid-template-columns:.85fr 1.15fr;gap:70px;padding:115px 0 110px}.faq-heading h2{font-size:43px;max-width:330px}.faq-list details{border-bottom:1px solid var(--line)}.faq-list summary{cursor:pointer;list-style:none;padding:23px 36px 23px 0;font-size:15px;font-weight:500;position:relative}.faq-list summary::-webkit-details-marker{display:none}.faq-list summary:after{content:'+';position:absolute;right:4px;top:18px;font-size:25px;font-weight:300;color:#7a816b}.faq-list details[open] summary:after{content:'−'}.faq-list details p{font-size:13px;line-height:1.9;color:var(--muted);padding:0 35px 24px 0;margin:0}.closing{position:relative;overflow:hidden;background:var(--lime);text-align:center;border-radius:35px;padding:65px 25px 60px}.closing:before,.closing:after{content:'✳';position:absolute;color:#a8bc53;font-size:120px;font-weight:300;line-height:1}.closing:before{left:6%;top:13%;transform:rotate(13deg)}.closing:after{right:7%;bottom:13%;font-size:85px;transform:rotate(-12deg)}.closing h2{position:relative;z-index:1;font-size:clamp(35px,4.5vw,59px);font-weight:450;letter-spacing:-2px;line-height:1.16;margin:20px 0 25px}.closing .button{position:relative;z-index:1}.site-footer{margin-top:60px}.footer-main{display:flex;justify-content:space-between;align-items:center;gap:30px;padding:35px 0}.footer-brand p{font-size:11px;color:var(--muted);margin:13px 0 0}.footer-brand .brand img{width:31px;height:31px;border-radius:10px}.footer-brand .wordmark{font-size:21px}.footer-links{display:flex;gap:30px;flex-wrap:wrap;font-size:12px;color:#62685c}.footer-bottom{border-top:1px solid var(--line);padding:23px 0 30px;font-size:10px;color:#858b7d;display:flex;justify-content:space-between;gap:18px}.footer-signature{letter-spacing:1.6px;font-size:9px;color:#879174}.back-home{font-size:12px;display:flex;align-items:center;gap:10px;color:var(--muted)}.back-home svg{width:15px;height:15px}.legal-header{padding:70px 0 52px;border-bottom:1px solid var(--line)}.legal-header h1{font-size:clamp(45px,6vw,76px);font-weight:450;letter-spacing:-3px;line-height:1.1;margin:24px 0}.legal-intro{max-width:660px;color:var(--muted);font-size:16px;line-height:1.85;margin-bottom:25px}.legal-meta{display:flex;align-items:center;gap:24px;font-size:11px;color:#828979}.print-button{border:1px solid #dfe2d7;background:none;font-size:11px;min-height:35px;border-radius:25px;padding:7px 15px}.legal-grid{display:grid;grid-template-columns:240px minmax(0,1fr);gap:74px;align-items:start;padding-top:45px;padding-bottom:70px}.doc-toc{position:sticky;top:126px;border-left:1px solid var(--line);padding-left:19px;font-size:12px;line-height:1.55}.doc-toc .eyebrow{font-size:9px;margin-bottom:18px}.doc-toc ol{list-style:none;padding:0;margin:0}.doc-toc li{margin-bottom:13px}.doc-toc a{color:#7e8574;display:block}.doc-toc a:hover,.doc-toc a[aria-current=location]{color:var(--ink)}.doc-toc a[aria-current=location]{font-weight:650}.doc-toc .text-link{margin-top:24px;font-size:10px;color:#798365}.legal-document{min-width:0;max-width:790px}.legal-summary{background:#e8eddc;border:1px solid #e2e7d7;border-radius:21px;padding:27px 30px;margin-bottom:42px}.legal-summary .eyebrow{font-size:9px}.legal-summary ul{padding-left:17px;margin-bottom:0;color:#626d50;font-size:13px;line-height:1.85}.legal-summary li+li{margin-top:7px}.document-section{scroll-margin-top:120px;margin:0 0 37px}.document-section h2{font-weight:550;font-size:22px;letter-spacing:-.5px;line-height:1.5;margin:0 0 15px}.document-section p,.document-section li{font-size:14px;color:#686f60;line-height:1.95}.document-section p{margin:0 0 13px}.document-section ul{padding-left:22px;margin:0 0 16px}.document-section li+li{margin-top:7px}.document-section strong{font-weight:600;color:#4a5340}.document-section a{color:#52683b;text-decoration:underline;text-underline-offset:3px;overflow-wrap:anywhere}.document-section .table-wrap{overflow-x:auto}.document-section table{width:100%;border-collapse:collapse;font-size:12px;line-height:1.8;margin:18px 0 24px}.document-section th{background:#ecefe3;font-weight:600;text-align:left;color:#515d43}.document-section th,.document-section td{padding:14px 16px;border:1px solid #e0e4d7;vertical-align:top}.document-section td{color:#68715c}.legal-end{margin-top:45px;padding-top:25px;border-top:1px solid var(--line)}.legal-page .site-footer{border-top:1px solid var(--line);margin-top:0}.lang-copy[lang]{display:none}html[data-lang=en] .lang-copy[lang=en],html[data-lang=zh] .lang-copy[lang=zh-CN]{display:block}html[data-lang=zh] .hero h1{font-size:clamp(47px,5vw,70px);line-height:1.18;letter-spacing:-2px}html[data-lang=zh] .serif{font-family:var(--sans);font-style:normal}html[data-lang=zh] .eyebrow{letter-spacing:2px}html[data-lang=zh] .section-heading h2,html[data-lang=zh] .approach h2{line-height:1.3}.js-only{display:none}.has-js .js-only{display:block}.no-js-note{font-size:12px;color:var(--muted);padding:8px 0}.has-js .no-js-note{display:none}
.has-js .scene-target{display:grid}
@keyframes shake{0%,100%{margin-left:0}25%{margin-left:-4px}75%{margin-left:4px}}
@media(min-width:1440px){.hero{padding-top:70px;padding-bottom:70px;min-height:760px}}
@media(max-width:1080px){.container{width:calc(100% - 56px)}.hero{padding-top:55px;min-height:640px}.hero h1{font-size:61px;letter-spacing:-3.1px}.hero-description{font-size:14px;max-width:360px}.demo-panel{padding:16px;width:96%}.word-chip{padding-inline:8px;font-size:12px}.demo-caption{font-size:8px}.app-grid{gap:18px}.phone-stage{padding:27px 23px 0;height:485px}.feature-copy{min-height:185px}.feature-copy h3{font-size:20px}.feature-copy p{font-size:12px}.approach{gap:50px}.privacy-banner{padding:45px;gap:20px}.privacy-banner h2{font-size:38px}.faq-section{gap:50px}.legal-grid{grid-template-columns:190px minmax(0,1fr);gap:40px}.nav-links{gap:20px}}
@media(max-width:760px){.container{width:calc(100% - 40px)}.header-inner{min-height:76px;gap:12px}.brand img{width:32px;height:32px;border-radius:10px}.wordmark{font-size:22px}.nav-links{display:none}.language-picker{padding:3px}.language-picker button{min-width:40px;font-size:11px;padding-inline:8px}.hero{display:flex;flex-direction:column;align-items:stretch;padding-top:45px;padding-bottom:43px;gap:10px;min-height:0}.hero-copy{padding-bottom:0;max-width:520px}.eyebrow{font-size:9px;letter-spacing:2px}.hero h1{font-size:clamp(53px,10vw,75px);letter-spacing:-2.6px;margin:23px 0 21px}.hero-description{max-width:470px;font-size:14px;line-height:1.85;margin-bottom:25px}.button{padding:13px 21px;min-height:48px}.platform-note{margin-top:13px;font-size:9px}.hero-visual{max-width:535px;align-self:center;width:100%;margin-top:0}.island-scene{margin-top:-10px}.floating-note{font-size:9px;padding:10px 14px;top:10%;right:3%}.floating-note:before{font-size:16px}.scene-target{width:44px;height:44px}.scene-target:before{font-size:20px}.demo-panel{margin-top:-52px;width:96%;border-radius:19px;padding:15px 16px}.demo-topline{margin-bottom:10px}.word-chip{font-size:12px;min-height:38px}.demo-status,.reset-demo{font-size:9px}.demo-caption{font-size:8px;margin-top:11px}.principles{padding:23px 0;justify-content:flex-start;gap:13px;align-items:stretch;font-size:10px}.principle{flex:1;gap:7px;align-items:flex-start;line-height:1.6}.principle .symbol{font-size:16px;line-height:1.2;padding-top:2px}.app-section{padding:66px 0}.section-heading{margin-bottom:35px}.section-heading h2,.approach h2{font-size:40px;letter-spacing:-1.6px;margin:18px 0}.section-heading p,.approach-intro{font-size:13px}.app-grid{display:flex;flex-direction:column;gap:36px}.app-feature{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:20px}.feature-copy{padding:0;min-height:0;order:2}.feature-label{font-size:8px;letter-spacing:1.3px}.feature-copy h3{font-size:21px;line-height:1.35;margin:10px 0}.feature-copy p{font-size:12px;line-height:1.85}.phone-stage{padding:21px 17px 0;border-radius:23px;height:340px}.phone{border-width:4px;border-radius:24px}.phone img{border-radius:19px}.screenshot-note{font-size:9px;line-height:1.7;margin-top:23px}.approach{grid-template-columns:1fr;gap:12px;padding:55px 0 65px}.approach-copy{padding-top:0}.approach-intro{max-width:470px}.approach-list{padding-top:0}.approach-item{padding:21px 0;gap:15px}.approach-item h3{font-size:16px}.approach-item p{font-size:12px;max-width:100%}.step-number{width:33px;height:33px;font-size:10px}.privacy-banner{grid-template-columns:1fr;padding:33px 27px;border-radius:26px;gap:15px}.privacy-banner h2{font-size:37px;letter-spacing:-1.5px}.privacy-banner p{font-size:13px}.privacy-art{min-height:235px}.privacy-mark{width:110px;height:130px}.privacy-art:before{width:200px;height:200px}.privacy-art:after{width:250px;height:160px}.privacy-tag{bottom:8px;font-size:10px}.faq-section{grid-template-columns:1fr;padding:65px 0;gap:15px}.faq-heading h2{font-size:37px;max-width:100%;letter-spacing:-1.4px;margin:15px 0 10px}.faq-list summary{font-size:14px;padding-block:21px}.faq-list details p{font-size:12px;padding-right:15px}.closing{border-radius:26px;padding:45px 20px}.closing h2{font-size:40px;letter-spacing:-1.5px;line-height:1.2}.closing:before{font-size:65px;left:0;top:15%}.closing:after{font-size:55px;right:2%;bottom:10%}.site-footer{margin-top:25px}.footer-main{align-items:flex-start;flex-direction:column;gap:27px;padding:30px 0}.footer-links{gap:25px;font-size:11px}.footer-bottom{font-size:9px;padding:20px 0 25px;flex-wrap:wrap}.footer-signature{font-size:8px}.back-home{font-size:11px}.back-home span{display:none}.legal-header{padding:42px 0 33px}.legal-header h1{font-size:48px;letter-spacing:-2px;margin:20px 0}.legal-intro{font-size:14px;line-height:1.8}.legal-meta{gap:15px;font-size:10px;flex-wrap:wrap}.print-button{font-size:10px;padding:6px 13px;min-height:32px}.legal-grid{grid-template-columns:1fr;gap:30px;padding-top:28px;padding-bottom:35px}.doc-toc{position:static;font-size:11px;border-left:0;border-bottom:1px solid var(--line);padding:0 0 18px}.doc-toc ol{grid-template-columns:1fr 1fr;gap:11px 20px}.doc-toc li{margin:0}.doc-toc .eyebrow{margin-bottom:15px}.doc-toc .text-link{display:none}.legal-summary{padding:21px 23px;margin-bottom:30px}.legal-summary ul{font-size:12px}.document-section{margin-bottom:30px}.document-section h2{font-size:20px}.document-section p,.document-section li{font-size:13px;line-height:1.9}.document-section th,.document-section td{padding:10px 12px}.document-section table{font-size:11px}html[data-lang=zh] .hero h1{font-size:clamp(43px,9.1vw,66px);letter-spacing:-1px}html[data-lang=zh] .feature-copy h3{font-size:19px}}
@media(max-width:390px){.container{width:calc(100% - 32px)}.hero h1{font-size:51px}.hero-description{font-size:13px}.island-scene{margin-top:-8px}.floating-note{top:6%;right:0;font-size:8px}.app-feature{gap:16px}.phone-stage{height:305px;padding:17px 12px 0}.feature-copy h3{font-size:19px}.feature-copy p{font-size:11px}.privacy-banner{padding:30px 23px}.closing h2{font-size:34px}.wordmark{font-size:21px}.language-picker button{min-width:37px}.doc-toc ol{gap:11px 15px}.legal-header h1{font-size:43px}.footer-links{gap:22px}}
@media(max-width:760px){html[data-lang=en] .doc-toc ol[lang=en],html[data-lang=zh] .doc-toc ol[lang=zh-CN]{display:grid}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation:none!important;transition:none!important}}
@media print{body{background:white;color:black}.site-header,.site-footer,.doc-toc,.print-button,.legal-end,.skip-link{display:none!important}.container{width:100%}.legal-header{padding:0 0 20px}.legal-header h1{font-size:34px}.legal-grid{display:block;padding-top:20px}.legal-document{max-width:none}.legal-summary{background:none;border:1px solid #ccc;padding:15px;break-inside:avoid}.document-section{scroll-margin:0}.document-section h2{break-after:avoid}.document-section p,.document-section li{font-size:10pt;color:black}.legal-intro{font-size:11pt}.document-section a{color:black}.document-section table{font-size:9pt}}