:root{
  --accent:#374a7c;
  --accent-soft:#eef1f8;
  --lv0:#d7dce2;
  --lv1:#e87470;
  --lv2:#f09c52;
  --lv3:#e3bd42;
  --lv4:#4db3a6;
  --lv5:#61ba73;
  /* darker "ink" shades: used wherever these colors sit as TEXT or a
     solid badge fill (white text on top) — keeps >=4.5:1 contrast on white */
  --lv0-ink:#66788d;
  --lv1-ink:#de352f;
  --lv2-ink:#b55d10;
  --lv3-ink:#8f7215;
  --lv4-ink:#378178;
  --lv5-ink:#3a8449;
  /* mid shades: used for icon strokes on white/near-white — >=3:1 contrast,
     the WCAG minimum for graphical/UI objects, while staying closer to the brand hue */
  --lv0-icon:#8594a7;
  --lv1-icon:#e76e6a;
  --lv2-icon:#e47514;
  --lv3-icon:#b38f1a;
  --lv4-icon:#46a397;
  --lv5-icon:#49a75c;
  --bg-canvas:#f5f7fa;
  --bg-surface:#ffffff;
  --text-primary:#26384e;
  --text-secondary:#879398;
  --border-subtle:#e2e7ec;
  --radius-sm:12px;
  --radius-md:16px;
  --radius-lg:24px;
  --radius-xl:28px;
  --radius-full:999px;
  --max:1280px;
  --font-serif:'Source Serif 4',Georgia,'Songti SC',serif;
  --font-sans:'Inter',-apple-system,BlinkMacSystemFont,'PingFang SC','Microsoft YaHei',sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  background:var(--bg-surface);
  color:var(--text-primary);
  font-family:var(--font-sans);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.wrap{width:min(calc(100% - 40px),var(--max));margin:auto}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  height:52px;padding:0 24px;border-radius:var(--radius-md);
  font-weight:600;font-size:15px;white-space:nowrap;
  border:1px solid var(--accent);cursor:pointer;transition:transform .15s ease,box-shadow .15s ease,opacity .15s ease;
}
.btn:hover{transform:translateY(-1px)}
.btn-primary{background:var(--accent);color:#fff;box-shadow:0 8px 20px rgba(55,74,124,.24)}
.btn-primary:hover{box-shadow:0 12px 26px rgba(55,74,124,.32)}
.btn-secondary{background:var(--bg-surface);color:var(--text-primary)}
.btn-on-dark{background:#fff;border-color:#fff;color:var(--accent)}

/* ---------- Header ---------- */
.site-header{
  position:sticky;top:0;z-index:30;
  background:rgba(255,255,255,.9);backdrop-filter:blur(14px);
  border-bottom:1px solid var(--border-subtle);
}
.header-inner{height:88px;display:flex;align-items:center;justify-content:space-between;gap:24px}
.brand{display:flex;align-items:center;gap:12px}
.brand-mark{
  width:44px;height:44px;border-radius:14px;background:var(--accent);
  color:#fff;font-family:var(--font-serif);font-weight:700;font-size:26px;
  display:flex;align-items:center;justify-content:center;flex-shrink:0;
}
.brand-name{font-family:var(--font-serif);font-weight:700;font-size:24px;white-space:nowrap}
.main-nav{display:flex;align-items:center;gap:40px}
.main-nav a{font-weight:600;font-size:15px;color:var(--text-primary);opacity:.82}
.main-nav a:hover{opacity:1}
.header-cta{display:flex;align-items:center;gap:16px}
.lang-toggle{
  border:1px solid var(--border-subtle);border-radius:var(--radius-full);background:none;
  color:var(--text-primary);font-weight:600;font-size:13px;padding:9px 16px;cursor:pointer;
  font-family:var(--font-sans);
}
.lang-toggle:hover{border-color:var(--accent);color:var(--accent)}
.lang-toggle.mobile{width:100%;padding:12px 16px;margin-top:4px}
.menu-toggle{
  display:none;width:44px;height:44px;border-radius:12px;border:1px solid var(--border-subtle);
  background:#fff;align-items:center;justify-content:center;cursor:pointer;flex-shrink:0;
}
.menu-toggle span{display:block;width:18px;height:2px;background:var(--text-primary);position:relative}
.menu-toggle span::before,.menu-toggle span::after{content:"";position:absolute;left:0;width:18px;height:2px;background:var(--text-primary)}
.menu-toggle span::before{top:-6px}
.menu-toggle span::after{top:6px}
.mobile-panel{
  display:none;flex-direction:column;gap:4px;padding:12px 0 20px;
  border-top:1px solid var(--border-subtle);
}
.mobile-panel a{padding:12px 4px;font-weight:600;font-size:15px;border-bottom:1px solid var(--border-subtle)}
.mobile-panel .btn{margin-top:12px;width:100%}
.mobile-panel.open{display:flex}

/* ---------- Section shells ---------- */
section{padding:100px 0}
.eyebrow{
  font-family:var(--font-sans);font-weight:600;font-size:13px;letter-spacing:.06em;
  text-transform:uppercase;color:var(--accent);margin:0 0 14px;
}
h1,h2,h3{font-family:var(--font-serif);font-weight:700;color:var(--text-primary);margin:0}
.section-head{max-width:760px;margin:0 auto 44px;text-align:center}
.section-head p{color:var(--text-secondary);font-size:17px;line-height:1.55;margin:14px 0 0}
.section-head h2{font-size:clamp(30px,4vw,38px);line-height:1.2}

/* ---------- Hero ---------- */
.hero{
  background:var(--bg-canvas);
  padding:72px 0 64px;
  overflow:hidden;
}
.hero-inner{display:grid;grid-template-columns:1fr 1fr;gap:64px;align-items:center}
.hero-copy h1{font-size:clamp(38px,5.2vw,64px);line-height:1.1;letter-spacing:-.01em;margin:14px 0 20px}
.hero-copy .lead{font-size:clamp(17px,1.6vw,20px);color:var(--text-secondary);line-height:1.55;max-width:500px;margin:0 0 32px}
.hero-actions{display:flex;gap:16px;flex-wrap:wrap;margin-bottom:20px}
.platform-note{font-size:13px;color:var(--text-secondary)}

.preview{display:flex;align-items:flex-start;gap:22px}
.wordlist-preview{
  position:relative;width:380px;max-width:100%;flex:1 1 380px;margin-top:44px;
  background:var(--bg-surface);border:1px solid var(--border-subtle);border-radius:var(--radius-xl);
  box-shadow:0 18px 40px rgba(26,41,71,.10);padding:22px 20px;
}
.wordlist-preview h3{font-size:26px;margin-bottom:4px}
.wordlist-preview .panel-meta{font-size:13px;color:var(--text-secondary);margin:0 0 18px}
.study-card-float{
  width:265px;flex:0 0 265px;
}
.level-accent-tag{
  position:absolute;right:-16px;bottom:-17px;background:var(--accent);color:#fff;
  font-weight:600;font-size:13px;padding:8px 18px;border-radius:17px;white-space:nowrap;
  box-shadow:0 10px 20px rgba(55,74,124,.24);
}

/* ---------- Word Row ---------- */
.word-row{
  display:flex;align-items:stretch;border-radius:var(--radius-md);border:1px solid var(--row-color,var(--lv0));
  background:linear-gradient(90deg,var(--row-tint,rgba(215,220,226,.05)),var(--row-tint,rgba(215,220,226,.05))),#fff;
  box-shadow:0 3px 6px var(--row-shadow,rgba(215,220,226,.04));
  margin-bottom:14px;overflow:hidden;
}
.word-row:last-child{margin-bottom:0}
.word-row .rail{width:5px;background:var(--row-color,var(--lv0));flex-shrink:0}
.word-row .content{flex:1;min-width:0;padding:12px 16px;display:flex;flex-direction:column;gap:6px;justify-content:center}
.word-row .top-row{display:flex;align-items:center;justify-content:space-between;gap:8px}
.word-row .word{font-family:var(--font-serif);font-weight:700;font-size:19px;color:var(--text-primary)}
.word-row .bottom-row{display:flex;align-items:center;gap:8px}
.word-row .subtitle{font-size:12px;color:var(--text-secondary)}

.dots{display:flex;gap:6px;flex-shrink:0}
.dots span{width:10px;height:10px;border-radius:50%;border:1.5px solid var(--row-color,var(--lv0));background:transparent}
.dots span.filled{background:var(--row-color,var(--lv0))}

.badge{
  display:inline-flex;align-items:center;justify-content:center;padding:8px 12px;border-radius:var(--radius-full);
  font-weight:600;font-size:13px;background:var(--row-ink,var(--lv0-ink));color:#fff;flex-shrink:0;
}

.row-lv0{--row-color:var(--lv0);--row-ink:var(--lv0-ink);--row-tint:rgba(215,220,226,.05);--row-shadow:rgba(215,220,226,.04)}
.row-lv1{--row-color:var(--lv1);--row-ink:var(--lv1-ink);--row-tint:rgba(232,116,112,.05);--row-shadow:rgba(232,116,112,.06)}
.row-lv2{--row-color:var(--lv2);--row-ink:var(--lv2-ink);--row-tint:rgba(240,156,82,.05);--row-shadow:rgba(240,156,82,.06)}
.row-lv3{--row-color:var(--lv3);--row-ink:var(--lv3-ink);--row-tint:rgba(227,189,66,.05);--row-shadow:rgba(227,189,66,.06)}
.row-lv4{--row-color:var(--lv4);--row-ink:var(--lv4-ink);--row-tint:rgba(77,179,166,.05);--row-shadow:rgba(77,179,166,.06)}
.row-lv5{--row-color:var(--lv5);--row-ink:var(--lv5-ink);--row-tint:rgba(97,186,115,.05);--row-shadow:rgba(97,186,115,.06)}

/* ---------- Study Card ---------- */
.study-card{
  border:1px solid var(--card-color,var(--lv4));border-radius:var(--radius-lg);
  background:linear-gradient(90deg,var(--card-tint,rgba(77,179,166,.03)),var(--card-tint,rgba(77,179,166,.03))),#fff;
  box-shadow:0 4px 14px var(--card-shadow,rgba(77,179,166,.08));
  padding:16px;display:flex;flex-direction:column;gap:10px;
}
.study-card-lv1{--card-color:var(--lv1);--card-ink:var(--lv1-ink);--card-icon:var(--lv1-icon);--card-tint:rgba(232,116,112,.03);--card-shadow:rgba(232,116,112,.08)}
.study-card-lv4{--card-color:var(--lv4);--card-ink:var(--lv4-ink);--card-icon:var(--lv4-icon);--card-tint:rgba(77,179,166,.03);--card-shadow:rgba(77,179,166,.08)}
.study-card .card-head{display:flex;align-items:center;justify-content:space-between}
.study-card .card-badge{
  background:var(--bg-surface);border:1px solid var(--card-color);color:var(--card-ink);
  font-weight:600;font-size:11px;padding:5px 10px;border-radius:var(--radius-full);
}
.study-card .card-tools{display:flex;gap:5px}
.study-card .card-tools .tool{
  width:34px;height:34px;border-radius:50%;display:flex;align-items:center;justify-content:center;
}
.study-card .card-tools svg{width:16px;height:16px;color:var(--card-icon)}
.study-card .card-word{font-family:var(--font-serif);font-weight:700;font-size:25px;text-align:center;text-transform:capitalize}
.study-card .card-ipa{font-family:var(--font-serif);font-size:13px;color:var(--text-secondary);text-align:center}
.study-card .context-image{
  border:1px solid var(--card-color);border-radius:var(--radius-md);height:116px;
  background:
    radial-gradient(120% 100% at 20% 0%, color-mix(in srgb,var(--card-color) 55%,white) 0%, transparent 55%),
    linear-gradient(160deg, color-mix(in srgb,var(--card-color) 30%,white) 0%, color-mix(in srgb,var(--card-color) 75%,#26384e) 100%);
  position:relative;overflow:hidden;
}
.study-card .context-image svg{position:absolute;left:0;bottom:0;width:100%;height:60%;opacity:.55}
.photo-pagination{display:flex;align-items:center;justify-content:center;gap:6px}
.photo-pagination span{width:5px;height:5px;border-radius:50%;background:var(--border-subtle)}
.photo-pagination span.active{background:var(--card-color);width:6px;height:6px}
.study-card .add-photo{
  border:1px solid var(--card-color);border-radius:var(--radius-sm);height:34px;
  display:flex;align-items:center;justify-content:center;gap:6px;
}
.study-card .add-photo svg{width:14px;height:14px;color:var(--card-icon)}
.study-card .add-photo span{font-family:var(--font-serif);font-size:10px;color:var(--card-ink)}
.study-card .example{
  background:color-mix(in srgb,var(--card-color) 8%,transparent);border-radius:var(--radius-sm);
  display:flex;align-items:center;gap:8px;padding:8px 11px;
}
.study-card .example .rail{width:3px;align-self:stretch;background:var(--card-color);border-radius:2px}
.study-card .example p{font-family:var(--font-serif);font-style:italic;font-size:11px;color:var(--text-primary);margin:0}
.study-card .divider{height:1px;background:var(--border-subtle);opacity:.72}
.study-card .def-head{display:flex;align-items:center;justify-content:space-between}
.study-card .def-head span{font-weight:700;font-size:9px;letter-spacing:.08em;text-transform:uppercase;color:var(--card-ink)}
.study-card .def-head svg{width:14px;height:14px;color:var(--card-icon)}
.study-card .def-body{font-family:var(--font-serif);font-size:11px;color:var(--text-primary);margin:0}
.study-card .mastery{display:flex;justify-content:center}
.study-card .mastery .dots span{width:8px;height:8px;border-color:var(--card-color)}
.study-card .mastery .dots span.filled{background:var(--card-color)}

/* ---------- Proficiency journey ---------- */
.journey-steps{
  display:grid;grid-template-columns:repeat(6,1fr);gap:20px;margin-top:44px;
}
.journey-step{display:flex;flex-direction:column;align-items:center;gap:8px;text-align:center}
.journey-step h3{font-size:18px}
.journey-step p{font-size:12px;color:var(--text-secondary);margin:0;line-height:1.5}
.journey-step .badge{align-self:center}

/* ---------- Two-col feature (WordList / Immersion) ---------- */
.feature{background:var(--bg-canvas)}
.feature.alt-surface{background:var(--bg-surface)}
.feature-inner{display:grid;grid-template-columns:1fr 1fr;gap:80px;align-items:center}
.feature-inner.reverse .feature-visual{order:2}
.feature-inner.reverse .feature-copy{order:1}
.feature-copy h2{font-size:clamp(30px,3.6vw,46px);line-height:1.18;margin:0 0 18px}
.feature-copy p.body{font-size:clamp(16px,1.4vw,18px);color:var(--text-secondary);line-height:1.6;max-width:540px;margin:0 0 24px}
.benefit-list{display:flex;flex-direction:column;gap:16px}
.benefit{display:flex;align-items:center;gap:12px;font-weight:600;font-size:15px}
.benefit .dot{width:10px;height:10px;border-radius:50%;background:var(--accent);flex-shrink:0}

.wordlist-panel{
  background:var(--bg-surface);border:1px solid var(--border-subtle);border-radius:var(--radius-xl);
  box-shadow:0 16px 36px rgba(26,41,71,.08);padding:22px 24px;max-width:420px;
}
.wordlist-panel h3{font-size:25px;margin-bottom:4px}
.wordlist-panel .panel-meta{font-size:12px;color:var(--text-secondary);margin:0 0 18px}

.color-logic{display:flex;align-items:center;gap:12px;margin-top:8px}
.color-logic .swatch{width:44px;height:44px;border-radius:50%;flex-shrink:0}
.color-logic .swatch.c1{background:var(--lv1)}
.color-logic .swatch.c2{background:var(--lv4);margin-left:-14px;border:3px solid var(--bg-canvas)}
.color-logic p{font-weight:600;font-size:14px;max-width:260px;margin:0}

.study-card-pair{display:flex;gap:28px;justify-content:center}
.study-card-pair .study-card{width:258px}

/* ---------- Feature cards ---------- */
.feature-cards-section{background:var(--bg-canvas)}
.feature-cards-row{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:44px}
.feature-card{
  background:var(--bg-surface);border:1px solid var(--border-subtle);border-radius:var(--radius-lg);
  padding:28px;display:flex;flex-direction:column;gap:16px;
}
.feature-card .icon-circle{
  width:52px;height:52px;border-radius:50%;background:var(--accent);
  display:flex;align-items:center;justify-content:center;
}
.feature-card .icon-circle svg{width:24px;height:24px;color:#fff}
.feature-card h3{font-size:20px}
.feature-card p{font-size:14px;color:var(--text-secondary);margin:0;line-height:1.55}

/* ---------- Proof ---------- */
.proof-inner{display:flex;gap:70px;align-items:center;justify-content:center;flex-wrap:wrap}
.metrics{display:flex;gap:60px;flex-wrap:wrap}
.metric{text-align:center;max-width:180px}
.metric strong{display:block;font-family:var(--font-serif);font-size:40px;color:var(--accent);line-height:1.1}
.metric span{display:block;font-size:13px;color:var(--text-secondary);margin-top:6px;line-height:1.4}
.testimonial{
  background:var(--bg-canvas);border:1px solid var(--border-subtle);border-radius:var(--radius-lg);
  padding:30px;max-width:500px;
}
.testimonial p.quote{font-family:var(--font-serif);font-weight:700;font-size:22px;line-height:1.4;margin:0 0 16px}
.testimonial .attribution{font-size:13px;color:var(--text-secondary)}

/* ---------- Final CTA ---------- */
.final-cta{background:var(--accent);color:#fff;text-align:center}
.final-cta .eyebrow{color:#fff}
.final-cta h2{color:#fff;font-size:clamp(30px,4.4vw,42px);line-height:1.25;max-width:820px;margin:0 auto 18px}
.final-cta p{font-size:17px;line-height:1.5;max-width:640px;margin:0 auto 32px;opacity:.92}

/* ---------- Footer ---------- */
.site-footer{padding:42px 0 34px;border-top:1px solid var(--border-subtle)}
.footer-main{display:flex;align-items:center;justify-content:space-between;gap:24px;flex-wrap:wrap}
.footer-main .brand-name{font-size:24px}
.footer-links{display:flex;gap:32px;flex-wrap:wrap}
.footer-links a{font-weight:600;font-size:14px}
.footer-links a:hover{color:var(--accent)}
.footer-divider{height:1px;background:var(--border-subtle);margin:24px 0}
.footer-meta{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;font-size:12px;color:var(--text-secondary)}

/* ---------- Responsive ---------- */
@media (max-width:960px){
  .main-nav{display:none}
  .header-cta .btn{display:none}
  .header-cta #lang-toggle{display:none}
  .menu-toggle{display:flex}
  .mobile-panel{display:none}
  .mobile-panel.open{display:flex}

  .hero-inner{grid-template-columns:1fr;gap:48px}
  .hero-copy{text-align:left}
  .preview{flex-direction:column}
  .wordlist-preview{width:100%;margin-top:0}
  .study-card-float{display:none}
  .level-accent-tag{display:none}

  .journey-steps{grid-template-columns:repeat(2,1fr);gap:28px 16px}

  .feature-inner{grid-template-columns:1fr;gap:40px}
  .feature-inner.reverse .feature-visual,
  .feature-inner.reverse .feature-copy{order:0}
  .wordlist-panel{max-width:100%}
  .study-card-pair{flex-wrap:wrap}
  .study-card-pair .study-card{width:100%;max-width:320px}

  .feature-cards-row{grid-template-columns:1fr}

  .proof-inner{flex-direction:column}
  .metrics{justify-content:center;gap:32px}
  .testimonial{max-width:100%}

  .footer-main{flex-direction:column;align-items:flex-start}
}

@media (max-width:640px){
  section{padding:64px 0}
  .header-inner{height:72px}
  .brand-mark{width:38px;height:38px;font-size:22px;border-radius:12px}
  .brand-name{font-size:20px}
  .hero{padding:48px 0}
  .hero-actions .btn{width:100%}
  .journey-steps{grid-template-columns:repeat(2,1fr)}
}