:root{
  --bg:#0b1220; --bg2:#101a2e; --card:#15223a; --card2:#1b2b47;
  --line:#26395c; --txt:#e8eefb; --mut:#9fb0cc; --dim:#6c7d9c;
  --acc:#f5b43c; --acc2:#ffd27a; --ok:#39d98a; --bad:#ff6b6b; --info:#5aa7ff;
  --r:14px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
body{background:var(--bg);color:var(--txt);font:16px/1.55 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Inter,sans-serif;min-height:100vh;display:flex;flex-direction:column}
button{font:inherit;cursor:pointer;border:0;background:none;color:inherit}

.topbar{position:sticky;top:0;z-index:10;display:flex;align-items:center;justify-content:space-between;gap:10px;padding:12px 18px;background:rgba(11,18,32,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line);flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:10px;cursor:pointer}
.brand-mark{font-size:26px;color:var(--acc);transform:rotate(-45deg)}
.brand-name{font-weight:800;font-size:18px;letter-spacing:.5px}
.brand-name span{color:var(--acc)}
.brand-sub{font-size:11px;color:var(--dim);letter-spacing:2px;text-transform:uppercase}
.nav{display:flex;gap:4px;flex-wrap:wrap}
.nav button{padding:8px 12px;border-radius:999px;color:var(--mut);font-size:14px;font-weight:600}
.nav button:hover{color:var(--txt);background:var(--card)}
.nav button.active{background:var(--acc);color:#1a1405}

main{flex:1;width:100%;max-width:880px;margin:0 auto;padding:22px 16px 60px}

.hero{padding:34px 8px 10px;text-align:center}
.hero h1{font-size:clamp(26px,5vw,40px);line-height:1.15;margin-bottom:12px}
.hero h1 em{color:var(--acc);font-style:normal}
.hero p{color:var(--mut);max-width:560px;margin:0 auto 22px}
.cta-row{display:flex;gap:10px;justify-content:center;flex-wrap:wrap;margin-bottom:8px}

.btn{display:inline-flex;align-items:center;gap:8px;padding:12px 20px;border-radius:12px;font-weight:700;background:var(--card2);color:var(--txt);border:1px solid var(--line);transition:transform .08s}
.btn:active{transform:scale(.97)}
.btn.primary{background:var(--acc);color:#1a1405;border-color:transparent}
.btn.ghost{background:transparent}
.btn.small{padding:8px 14px;font-size:14px}
.btn:disabled{opacity:.45;cursor:default}

.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px;margin-top:18px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:18px}
.card h3{font-size:16px;margin-bottom:6px}
.card p{color:var(--mut);font-size:14px}
.card.click{cursor:pointer;transition:border-color .15s, transform .08s}
.card.click:hover{border-color:var(--acc)}
.card.click:active{transform:scale(.99)}

.module-head{display:flex;align-items:center;gap:10px;margin-bottom:6px}
.chip{font-size:11px;font-weight:700;letter-spacing:1px;text-transform:uppercase;padding:3px 9px;border-radius:999px;background:var(--bg2);color:var(--acc);border:1px solid var(--line)}
.chip.ok{color:var(--ok)}
.chip.info{color:var(--info)}

.lesson{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:26px 22px;margin-top:14px}
.lesson h2{margin-bottom:4px}
.lesson h4{margin:20px 0 8px;color:var(--acc2)}
.lesson p{margin:10px 0;color:#cfdaf0}
.lesson ul{margin:8px 0 8px 22px;color:#cfdaf0}
.lesson li{margin:5px 0}
.lesson table{width:100%;border-collapse:collapse;margin:12px 0;font-size:14px}
.lesson th,.lesson td{border:1px solid var(--line);padding:7px 10px;text-align:left}
.lesson th{background:var(--bg2);color:var(--acc2)}
.radio{display:block;background:#0d1626;border-left:3px solid var(--acc);border-radius:8px;padding:10px 14px;margin:10px 0;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:14px;color:#ffe9bd;white-space:pre-wrap}
.say{color:var(--info);font-weight:700;background:none;font-size:15px;padding:2px 6px}
.say:hover{color:var(--acc)}

.toolrow{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap;margin-top:18px}

.qwrap{margin-top:16px}
.qmeta{display:flex;justify-content:space-between;align-items:center;color:var(--mut);font-size:14px;margin-bottom:10px;flex-wrap:wrap;gap:8px}
.timer{font-family:ui-monospace,Menlo,monospace;font-weight:800;font-size:18px;color:var(--acc)}
.timer.low{color:var(--bad);animation:blink 1s step-end infinite}
@keyframes blink{50%{opacity:.4}}
.question{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:22px}
.question h3{font-size:17px;margin-bottom:16px;line-height:1.5}
.opts{display:flex;flex-direction:column;gap:9px}
.opt{display:flex;gap:10px;align-items:flex-start;text-align:left;background:var(--bg2);border:1px solid var(--line);border-radius:10px;padding:12px 14px;font-size:15px;color:var(--txt);transition:border-color .12s}
.opt:hover{border-color:var(--acc)}
.opt .key{font-weight:800;color:var(--acc);min-width:18px}
.opt.sel{border-color:var(--info);background:#14233f}
.opt.right{border-color:var(--ok);background:#10301f}
.opt.wrong{border-color:var(--bad);background:#391b1b}
.exp{margin-top:14px;padding:12px 14px;border-radius:10px;background:var(--bg2);border-left:3px solid var(--info);color:var(--mut);font-size:14px}
.progressbar{height:6px;background:var(--bg2);border-radius:99px;overflow:hidden;margin:10px 0 16px}
.progressbar i{display:block;height:100%;background:var(--acc)}

.score{ text-align:center;padding:36px 16px}
.score .big{font-size:56px;font-weight:900}
.score .big.ok{color:var(--ok)} .score .big.bad{color:var(--bad)}
.score p{color:var(--mut);margin-top:6px}

.flash{max-width:430px;margin:26px auto;perspective:900px}
.flashcard{position:relative;height:240px;border-radius:18px;cursor:pointer;transform-style:preserve-3d;transition:transform .45s}
.flashcard.flip{transform:rotateY(180deg)}
.face{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:8px;border-radius:18px;backface-visibility:hidden;border:1px solid var(--line)}
.face.front{background:var(--card2)}
.face.back{background:#2b2410;transform:rotateY(180deg)}
.face .big{font-size:64px;font-weight:900}
.face .word{font-size:34px;font-weight:800;color:var(--acc2)}
.face .ipa{color:var(--mut)}

.statrow{display:flex;gap:12px;flex-wrap:wrap;margin-top:16px}
.stat{flex:1;min-width:140px;background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:16px;text-align:center}
.stat .n{font-size:30px;font-weight:900;color:var(--acc)}
.stat .l{font-size:12px;color:var(--mut);text-transform:uppercase;letter-spacing:1px}
.histlist{margin-top:14px;display:flex;flex-direction:column;gap:8px}
.histitem{display:flex;justify-content:space-between;gap:10px;background:var(--card);border:1px solid var(--line);border-radius:10px;padding:10px 14px;font-size:14px}
.histitem .ok{color:var(--ok);font-weight:700}.histitem .bad{color:var(--bad);font-weight:700}

.footer{border-top:1px solid var(--line);padding:20px 18px;color:var(--mut);font-size:13px;text-align:center}
.footer .fine{color:var(--dim);font-size:11.5px;margin-top:6px;max-width:640px;margin-inline:auto}

@media (max-width:620px){
  .topbar{padding:10px 12px}
  .nav button{padding:7px 9px;font-size:13px}
  .lesson{padding:20px 16px}
}