:root{
  --bg:#fffdf9;--surface:#ffffff;--ink:#172033;--muted:#687386;--line:rgba(23,32,51,.10);
  --green:#16a36a;--green-dark:#0d7b4f;--mint:#e8fff4;--mint-2:#c9f6df;
  --coral:#ff6b5f;--coral-soft:#fff0ec;--blue:#4f7cff;--blue-soft:#eef2ff;
  --purple:#8b5cf6;--purple-soft:#f4efff;--yellow:#ffbf3f;--pink:#ec5ca2;
  --shadow:0 24px 70px rgba(23,32,51,.09);--radius:30px;
}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.62;background:radial-gradient(circle at 6% 6%,rgba(139,92,246,.13),transparent 23%),radial-gradient(circle at 94% 12%,rgba(79,124,255,.12),transparent 24%),radial-gradient(circle at 88% 52%,rgba(236,92,162,.08),transparent 22%),linear-gradient(180deg,#fffdf9 0%,#fbfbff 52%,#fffaf7 100%);-webkit-font-smoothing:antialiased}a{color:inherit}
.site-header{height:74px;position:sticky;top:0;z-index:20;display:flex;align-items:center;justify-content:space-between;padding:0 max(22px,calc((100vw - 1120px)/2));background:rgba(255,253,249,.88);backdrop-filter:blur(18px);border-bottom:1px solid var(--line)}.site-header a{text-decoration:none}.brand{display:flex;align-items:center;gap:10px;font-weight:900;letter-spacing:-.035em}.brand-mark{width:31px;height:31px;border-radius:11px;display:grid;place-items:center;color:#fff;background:linear-gradient(135deg,var(--purple),var(--blue));box-shadow:0 8px 18px rgba(79,124,255,.2)}.header-actions{display:flex;align-items:center;gap:8px}.header-course,.header-level{padding:8px 12px;border-radius:999px;font-size:13px;font-weight:800}.header-course:hover{background:#fff}.header-level{background:var(--blue-soft);color:#3557c7;border:1px solid #d9e1ff}
.lesson-layout,.course-layout{width:min(1120px,calc(100% - 36px));margin:0 auto 90px}.breadcrumbs{display:flex;gap:8px;align-items:center;flex-wrap:wrap;padding:25px 0 6px;color:var(--muted);font-size:13px}.breadcrumbs a{text-decoration:none}.breadcrumbs a:hover{color:var(--blue)}
.hero,.course-hero{position:relative;padding:54px 0 34px}.hero-copy{max-width:950px}.hero h1,.course-hero h1{font-size:clamp(48px,8vw,88px);line-height:.92;letter-spacing:-.065em;margin:18px 0 22px;font-weight:900}.objective,.lead{font-size:clamp(19px,2.2vw,25px);line-height:1.5;color:var(--muted);max-width:800px;margin:0}.pill{display:inline-flex;align-items:center;padding:8px 13px;border-radius:999px;border:1px solid rgba(79,124,255,.18);background:linear-gradient(90deg,#fff,#f4efff);font-size:11px;line-height:1;font-weight:900;letter-spacing:.12em;color:#6844c5}.hero-meta{display:flex;flex-wrap:wrap;gap:9px;margin-top:24px}.hero-meta span{padding:7px 10px;border-radius:999px;background:rgba(255,255,255,.78);border:1px solid var(--line);font-size:12px;font-weight:800;color:#536174}
.video-frame,.video-placeholder{aspect-ratio:16/9;overflow:hidden;border-radius:32px;margin:14px 0 34px;background:#111827;box-shadow:0 34px 90px rgba(23,32,51,.18);border:1px solid rgba(23,32,51,.08)}.video-frame iframe{width:100%;height:100%;border:0}.video-placeholder{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;color:white;background:radial-gradient(circle at 30% 20%,rgba(139,92,246,.32),transparent 30%),radial-gradient(circle at 80% 75%,rgba(22,163,106,.28),transparent 30%),linear-gradient(145deg,#172033,#273657)}.video-orb{width:78px;height:78px;border-radius:999px;display:grid;place-items:center;background:#fff;color:#172033;font-size:24px;padding-left:4px;box-shadow:0 14px 38px rgba(0,0,0,.22)}.video-placeholder>span{font-size:clamp(28px,5vw,48px);font-weight:900;letter-spacing:-.04em}.video-placeholder small{color:#dbe3f4;font-size:14px}
.section{position:relative;overflow:hidden;background:rgba(255,255,255,.92);border:1px solid var(--line);border-radius:var(--radius);padding:clamp(27px,4.5vw,50px);margin:18px 0;box-shadow:0 12px 38px rgba(23,32,51,.045)}.section h2{font-size:clamp(30px,4.5vw,46px);line-height:1.03;letter-spacing:-.05em;margin:9px 0 20px;font-weight:900}.section>p,.section-intro{font-size:17px;color:#4f5c70}.section-label{display:flex;align-items:center;gap:8px;font-size:11px;line-height:1;text-transform:uppercase;letter-spacing:.14em;font-weight:900;color:#58667a}.section-dot{width:8px;height:8px;border-radius:999px;background:var(--blue);box-shadow:0 0 0 4px rgba(79,124,255,.11)}.section-dot.coral{background:var(--coral);box-shadow:0 0 0 4px rgba(255,107,95,.10)}.section-dot.purple{background:var(--purple);box-shadow:0 0 0 4px rgba(139,92,246,.10)}.section-dot.green{background:var(--green);box-shadow:0 0 0 4px rgba(22,163,106,.10)}
.concept-section{background:linear-gradient(145deg,#fff 0%,#f5f8ff 100%)}.key-point{display:flex;gap:14px;align-items:flex-start;margin-top:28px;padding:21px 23px;border-radius:22px;background:linear-gradient(135deg,var(--blue-soft),#f5f0ff);border:1px solid #dce3ff}.key-icon{width:34px;height:34px;flex:0 0 34px;border-radius:11px;display:grid;place-items:center;background:var(--blue);color:#fff;font-weight:900}.key-point strong{font-size:12px;text-transform:uppercase;letter-spacing:.1em;color:#3557c7}.key-point p{margin:5px 0 0;font-size:16px}
.examples-section{background:linear-gradient(145deg,#fff 0%,#fff9f6 100%)}.example-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px}.example-card{display:flex;align-items:center;gap:13px;min-height:78px;padding:18px 20px;border-radius:20px;border:1px solid rgba(23,32,51,.09);background:#fff;font-size:18px;font-weight:750;box-shadow:0 8px 20px rgba(23,32,51,.025)}.example-card:nth-child(3n+1){background:var(--mint)}.example-card:nth-child(3n+2){background:var(--coral-soft)}.example-card:nth-child(3n){background:var(--blue-soft)}.example-num{font-size:11px;letter-spacing:.08em;color:#8290a3;font-weight:900}
.practice-section{background:linear-gradient(145deg,#fff 0%,#fbf8ff 100%)}.practice-list{list-style:none;padding:0;margin:22px 0 0;display:grid;gap:11px;counter-reset:item}.practice-list li{position:relative;padding:15px 17px 15px 48px;border-radius:17px;border:1px solid rgba(139,92,246,.12);background:#fff;font-size:16px}.practice-list li:before{counter-increment:item;content:counter(item);position:absolute;left:14px;top:13px;width:25px;height:25px;border-radius:9px;display:grid;place-items:center;background:var(--purple-soft);color:#6844c5;font-size:11px;font-weight:900}
.labs{background:linear-gradient(145deg,#172033 0%,#22314f 55%,#172033 100%);color:#fff;border-color:rgba(255,255,255,.08);box-shadow:0 30px 80px rgba(23,32,51,.16)}.labs:before{content:"";position:absolute;width:360px;height:360px;border-radius:999px;right:-130px;top:-170px;background:radial-gradient(circle,rgba(139,92,246,.32),transparent 68%)}.labs .section-label{color:#cbd5e1}.labs h2{color:#fff}.labs-heading{position:relative;z-index:1;display:flex;align-items:flex-start;justify-content:space-between;gap:20px}.labs-lede{max-width:720px;color:#cbd5e1!important;margin-top:-8px!important}.labs-badge{flex:0 0 auto;padding:7px 10px;border-radius:999px;background:rgba(255,255,255,.09);border:1px solid rgba(255,255,255,.12);font-size:10px;font-weight:900;letter-spacing:.14em}.lab-grid{position:relative;z-index:1;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin-top:28px}.lab-card{text-decoration:none;color:var(--ink);min-height:285px;padding:23px;border-radius:25px;display:flex;flex-direction:column;justify-content:space-between;gap:20px;transition:transform .18s ease,box-shadow .18s ease;background:var(--mint);border:1px solid #ccefe0}.lab-card.lab-pronunciation{background:#fff0ec;border-color:#ffd8cd}.lab-card.lab-listening{background:#eef2ff;border-color:#d8e0ff}.lab-card:hover{transform:translateY(-5px);box-shadow:0 22px 55px rgba(0,0,0,.16)}.lab-card-top{display:flex;align-items:center;gap:10px}.lab-icon{width:42px;height:42px;border-radius:14px;display:grid;place-items:center;background:rgba(255,255,255,.72);font-size:18px}.lab-kicker{font-size:10px;line-height:1.25;letter-spacing:.1em;text-transform:uppercase;font-weight:900;color:#5c6876}.lab-card h3{font-size:25px;line-height:1.05;letter-spacing:-.035em;margin:12px 0}.lab-card p{margin:0;color:#5e6878}.lab-cta{display:flex;align-items:center;justify-content:space-between;gap:10px;font-weight:900}.lab-cta span{width:34px;height:34px;border-radius:999px;display:grid;place-items:center;background:rgba(255,255,255,.72)}
.completion{display:flex;align-items:center;justify-content:space-between;gap:28px;background:linear-gradient(135deg,#effdf7,#f4efff)}.completion p{margin-bottom:0}.completion button,.course-progress a{border:0;background:linear-gradient(90deg,var(--purple),var(--blue));color:#fff;border-radius:999px;padding:13px 19px;font:inherit;font-weight:900;cursor:pointer;text-decoration:none;display:inline-block;box-shadow:0 12px 28px rgba(79,124,255,.2)}.completion button:hover,.course-progress a:hover{transform:translateY(-1px)}.completion button.is-complete{background:linear-gradient(90deg,var(--green),#36c887)}
.lesson-nav{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:28px 0}.nav-link{background:rgba(255,255,255,.82);border:1px solid var(--line);padding:20px 22px;border-radius:22px;text-decoration:none;color:var(--ink);font-weight:850;transition:.16s ease}.nav-link:hover{background:#fff;transform:translateY(-2px);box-shadow:0 12px 30px rgba(23,32,51,.06)}.nav-link.next{text-align:right}.source{margin-top:26px;color:var(--muted)}.source summary{cursor:pointer;font-weight:700}.source pre{white-space:pre-wrap;background:#fff;border:1px solid var(--line);padding:22px;border-radius:22px}
.course-hero{max-width:920px}.course-hero:after{content:"";display:block;width:130px;height:9px;border-radius:999px;background:linear-gradient(90deg,var(--yellow),var(--coral),var(--pink));margin-top:28px}.course-progress{margin-top:28px;background:#fff;border:1px solid var(--line);border-radius:26px;padding:24px;box-shadow:0 10px 34px rgba(23,32,51,.05)}.progress-track{height:9px;background:#e8edf6;border-radius:999px;overflow:hidden;margin:13px 0 19px}.progress-track span{height:100%;background:linear-gradient(90deg,var(--green),#3ccf91);display:block}.lesson-list{display:grid;gap:13px}.lesson-card{display:grid;grid-template-columns:64px 1fr 20px;gap:20px;align-items:center;background:rgba(255,255,255,.86);border:1px solid var(--line);border-radius:24px;padding:24px;text-decoration:none;color:var(--ink);transition:.17s ease}.lesson-card:hover{transform:translateY(-3px);box-shadow:var(--shadow);background:#fff}.lesson-card h2{font-size:21px;letter-spacing:-.025em;margin:2px 0}.lesson-card p{margin:3px 0;color:var(--muted)}.lesson-number{font-weight:900;font-size:23px;color:var(--blue)}.lesson-card.completed .status{width:12px;height:12px;border-radius:50%;background:var(--green);box-shadow:0 0 0 4px rgba(22,163,106,.11)}
@media(max-width:900px){.lab-grid{grid-template-columns:1fr}.lab-card{min-height:0}.labs-heading{flex-direction:column}.hero h1,.course-hero h1{font-size:clamp(44px,11vw,72px)}}@media(max-width:700px){.example-grid{grid-template-columns:1fr}.completion{align-items:flex-start;flex-direction:column}.lesson-card{grid-template-columns:44px 1fr 14px}.lesson-card p{display:none}.site-header{padding:0 14px}.header-course{display:none}.hero,.course-hero{padding-top:34px}.lesson-layout,.course-layout{width:min(100% - 22px,1120px)}.section{border-radius:25px;padding:24px 20px}.lesson-nav{grid-template-columns:1fr}.nav-link.next{text-align:left}.video-frame,.video-placeholder{border-radius:24px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}