:root{--ink:#1d1d1f;--grey:#6e6e73;--line:#e5e5ea;--accent:#0a5cff;--bg:#fff;--soft:#f5f5f7}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:-apple-system,"SF Pro Display","Helvetica Neue",Helvetica,Arial,sans-serif;color:var(--ink);background:var(--bg);-webkit-font-smoothing:antialiased}
a{color:var(--accent);text-decoration:none}
.wrap{max-width:1080px;margin:0 auto;padding:0 24px}
header.site{position:sticky;top:0;background:rgba(255,255,255,.85);backdrop-filter:blur(12px);border-bottom:1px solid var(--line);z-index:50}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;gap:10px 20px;min-height:60px;padding-top:8px;padding-bottom:8px}
.brand{font-weight:700;font-size:20px;color:var(--ink);white-space:nowrap}
.brand .fx{color:var(--accent)}
nav.main{display:flex;align-items:center}
nav.main a{color:var(--ink);margin-left:26px;font-size:15px;white-space:nowrap}
.hright{display:flex;align-items:center;gap:14px}
.langsw{display:flex;border:1px solid var(--line);border-radius:980px;overflow:hidden;background:#fff;flex:none}
.langsw button{border:none;background:transparent;font-family:inherit;font-size:13px;font-weight:600;padding:7px 13px;cursor:pointer;color:var(--grey)}
.langsw button.on{background:var(--ink);color:#fff}
@media(max-width:760px){
header.site .wrap{flex-wrap:wrap}
.brand{order:1}
.brand .bword{display:none}
.hright{order:2;margin-left:auto}
nav.main{order:3;flex:0 0 100%;gap:24px;overflow-x:auto;padding:2px 0 4px}
nav.main a{margin-left:0}
header.site .pill{padding:9px 18px;font-size:14px}
.langsw button{padding:7px 11px}
}
.pill{display:inline-block;background:var(--accent);color:#fff!important;padding:11px 24px;border-radius:980px;font-size:15px;font-weight:600;border:none;cursor:pointer;white-space:nowrap}
.pill.ghost{background:var(--soft);color:var(--ink)!important}
.hero{padding:88px 0 56px;text-align:center}
.hero h1{font-size:52px;line-height:1.08;letter-spacing:-.02em;font-weight:700}
.hero p{font-size:20px;color:var(--grey);max-width:640px;margin:20px auto 30px;line-height:1.45}
.eyebrow{color:var(--accent);font-weight:600;font-size:15px;letter-spacing:.04em;text-transform:uppercase}
section{padding:56px 0}
h2{font-size:36px;letter-spacing:-.01em;margin-bottom:10px}
.sub{color:var(--grey);font-size:18px;margin-bottom:34px}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px}
.card{background:var(--soft);border-radius:20px;padding:30px}
.card h3{font-size:22px;margin-bottom:8px}
.card p{color:var(--grey);line-height:1.5;font-size:16px}
.card .meta{margin-top:16px;font-size:14px;color:var(--grey)}
.price-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px}
.tier{background:#fff;border:1px solid var(--line);border-radius:20px;padding:32px}
.tier.hot{border:2px solid var(--accent)}
.tier .price{font-size:44px;font-weight:700;margin:12px 0 4px}
.tier .per{color:var(--grey);font-size:16px}
.tier ul{list-style:none;margin:18px 0 24px}
.tier li{padding:7px 0;font-size:16px;border-bottom:1px solid var(--soft)}
.tier li:last-child{border-bottom:none}
.tag{display:inline-block;background:var(--soft);color:var(--accent);font-size:13px;font-weight:600;padding:4px 12px;border-radius:980px}
footer{border-top:1px solid var(--line);padding:36px 0;color:var(--grey);font-size:14px;text-align:center}
/* course player */
.course-head{padding:48px 0 8px}
.course-head h1{font-size:40px;letter-spacing:-.01em}
.lang-tabs{display:flex;gap:10px;margin:22px 0}
.lang-tabs button{border:1px solid var(--line);background:#fff;border-radius:980px;padding:9px 20px;font-size:15px;cursor:pointer;font-family:inherit}
.lang-tabs button.on{background:var(--ink);color:#fff;border-color:var(--ink)}
.layout{display:grid;grid-template-columns:340px 1fr;gap:28px;align-items:start;padding-bottom:70px}
@media(max-width:860px){.layout{grid-template-columns:1fr}}
.lessons{background:var(--soft);border-radius:18px;padding:10px;max-height:78vh;overflow:auto}
.lessons h4{font-size:14px;text-transform:uppercase;letter-spacing:.05em;color:var(--grey);padding:14px 12px 8px}
.lesson{display:flex;gap:10px;align-items:baseline;width:100%;text-align:left;background:none;border:none;font-family:inherit;font-size:15px;padding:10px 12px;border-radius:10px;cursor:pointer;color:var(--ink)}
.lesson:hover{background:#e9e9ee}
.lesson.on{background:#fff;box-shadow:0 1px 4px rgba(0,0,0,.08)}
.lesson .num{color:var(--grey);font-size:13px;min-width:22px}
.lesson .st{margin-left:auto;font-size:12px;color:var(--grey);white-space:nowrap}
.playerbox{position:relative;background:#000;border-radius:18px;overflow:hidden;aspect-ratio:16/9}
.playerbox iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.gate{position:absolute;inset:0;background:rgba(20,20,25,.92);color:#fff;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:30px;gap:14px}
.gate h3{font-size:26px}
.gate p{color:#c7c7cc;max-width:420px;line-height:1.5}
.ltitle{font-size:24px;margin:20px 0 4px}
.lnote{color:var(--grey);font-size:15px}
.soon{background:#fff;border:1px dashed var(--line);color:var(--ink)}
.pill.sm{padding:8px 16px;font-size:13px}
#authbox{display:flex;align-items:center;gap:10px}
#authbox .who{font-size:13px;color:var(--grey);max-width:170px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
@media(max-width:760px){#authbox .who{display:none}}
.acc-wrap{max-width:520px;margin:0 auto;padding:56px 24px 80px}
.acc-card{background:var(--soft);border-radius:20px;padding:30px;margin-top:26px}
.acc-card label{display:block;font-size:14px;font-weight:600;margin:14px 0 6px}
.acc-card input{width:100%;padding:13px 16px;border:1px solid var(--line);border-radius:12px;font-size:16px;font-family:inherit;background:#fff}
.acc-card .pill{width:100%;text-align:center;margin-top:18px}
.acc-msg{display:none;background:#e8f4e8;border:1px solid #bfe3bf;color:#14532d;border-radius:12px;padding:12px 16px;font-size:15px;margin-top:16px}
.acc-err{display:none;background:#fdecec;border:1px solid #f3c2c2;color:#7f1d1d;border-radius:12px;padding:12px 16px;font-size:15px;margin-top:16px}
.tier .pill{margin-top:6px}