:root{
  --bg:#f4f7fc;--card:#fff;--soft:#f8fbff;--text:#101827;--muted:#66758b;--line:#d8e2ef;
  --blue:#2563eb;--blue2:#1d4ed8;--green:#16a34a;--orange:#f59e0b;--red:#dc2626;--purple:#7c3aed;
  --shadow:0 18px 55px rgba(15,23,42,.10);--radius:22px;
}
*{box-sizing:border-box}
html,body{min-height:100%;margin:0}
body{font-family:Inter,Segoe UI,Arial,Helvetica,sans-serif;background:linear-gradient(180deg,#f8fbff,#edf3fb);color:var(--text)}
button,input,textarea,select{font:inherit}
button{border:0;border-radius:14px;padding:11px 15px;background:var(--blue);color:#fff;font-weight:850;cursor:pointer;box-shadow:0 9px 24px rgba(37,99,235,.18)}
button:hover{background:var(--blue2)}
button.secondary{background:#e8f0fb;color:#17315c;box-shadow:none;border:1px solid var(--line)}
button.ghost{background:transparent;color:var(--blue);box-shadow:none;border:1px solid var(--line)}
button.good{background:var(--green)}button.warn{background:var(--orange);color:#1f2937}button.bad{background:var(--red)}button.purple{background:var(--purple)}
button.small{font-size:12px;padding:7px 10px;border-radius:10px}button:disabled{opacity:.55;cursor:not-allowed}
input,textarea,select{width:100%;padding:11px;border:1px solid var(--line);border-radius:14px;background:#fff;color:var(--text);outline:none}
textarea{resize:vertical;min-height:58px}
label{display:block;font-size:12px;color:var(--muted);font-weight:850;margin:9px 0 5px}
.appTop{position:sticky;top:0;z-index:20;display:flex;justify-content:space-between;align-items:center;gap:12px;padding:14px 18px;background:rgba(255,255,255,.94);border-bottom:1px solid var(--line);backdrop-filter:blur(14px)}
.brand{display:flex;gap:12px;align-items:center}.logo{width:46px;height:46px;border-radius:16px;background:linear-gradient(135deg,#1d4ed8,#60a5fa);display:grid;place-items:center;color:white;font-weight:950}.brand h1{font-size:20px;margin:0}.brand p{font-size:12px;color:var(--muted);margin:3px 0 0}
.topActions{display:flex;gap:8px;flex-wrap:wrap;justify-content:flex-end}
.shell{display:grid;grid-template-columns:284px 1fr;gap:18px;padding:18px;max-width:1760px;margin:0 auto}
.side{position:sticky;top:82px;height:calc(100vh - 102px);overflow:auto;background:rgba(255,255,255,.86);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:14px}
.main{min-width:0}.card{background:rgba(255,255,255,.96);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:18px;margin-bottom:18px}.hero{background:linear-gradient(135deg,#0f172a,#1e3a8a 55%,#2563eb);color:white;border:0}.hero .hint{color:#dbeafe}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}.sideStats{display:grid;grid-template-columns:1fr 1fr;gap:8px}.stat{background:var(--soft);border:1px solid var(--line);border-radius:17px;padding:13px}.hero .stat{background:rgba(255,255,255,.13);border-color:rgba(255,255,255,.19)}.stat strong{font-size:28px;display:block}.stat span{font-size:12px;color:var(--muted);font-weight:850}.hero .stat span{color:#dbeafe}
.nav{display:grid;gap:8px;margin:13px 0}.nav button{width:100%;text-align:left;box-shadow:none;background:#f1f5f9;color:#1e293b;border:1px solid var(--line)}.nav button.active{background:var(--blue);color:white;border-color:var(--blue)}
.quickBox{background:#f8fbff;border:1px solid var(--line);border-radius:18px;padding:12px;margin-top:12px}
.viewHead{display:flex;justify-content:space-between;align-items:flex-start;gap:12px}.hint{color:var(--muted);font-size:13px;line-height:1.45}.toolbar{display:flex;gap:8px;flex-wrap:wrap;align-items:center}.grid2{display:grid;grid-template-columns:1fr 1fr;gap:14px}.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.pill{display:inline-flex;border-radius:999px;padding:5px 9px;font-size:12px;font-weight:950;background:#e8f0fb;color:#17315c;align-items:center}.pill.good{background:#dcfce7;color:#166534}.pill.warn{background:#fef3c7;color:#92400e}.pill.bad{background:#fee2e2;color:#991b1b}.pill.blue{background:#dbeafe;color:#1d4ed8}.pill.purple{background:#ede9fe;color:#5b21b6}
.progressbar{height:10px;background:#e5e7eb;border-radius:999px;overflow:hidden}.progressbar i{display:block;height:100%;background:linear-gradient(90deg,#2563eb,#22c55e)}
.focus{border:1px solid var(--line);background:#fbfdff;border-radius:18px;padding:16px}.focus h3{margin:6px 0}
.trainerCard{text-align:center;padding:26px}.prompt{font-size:28px;font-weight:950;margin:15px 0 10px}.answer{font-size:30px;font-weight:950;color:#1d4ed8;margin:12px auto;padding:16px;border-radius:18px;background:#eff6ff;border:1px solid #dbeafe;max-width:900px}.hidden{filter:blur(9px);user-select:none}.now{background:#0f172a;color:white;border-radius:18px;padding:14px;margin-top:12px}.now .hint{color:#cbd5e1}
.courseShell{display:grid;grid-template-columns:330px 1fr;gap:16px}
.coursePanel{position:sticky;top:88px;align-self:start}
.courseCard{text-align:center}
.courseHeader{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:12px}
.lessonDots{display:grid;grid-template-columns:repeat(10,1fr);gap:6px;margin:10px 0}
.dot{border:1px solid var(--line);background:#fff;color:#334155;border-radius:12px;min-height:36px;font-weight:900;box-shadow:none;padding:6px 0}
.dot.current{background:var(--blue);color:white;border-color:var(--blue)}.dot.done{background:#dcfce7;color:#166534;border-color:#86efac}.dot.problem{background:#fee2e2;color:#991b1b;border-color:#fecaca}
.stageBar{display:flex;gap:8px;overflow-x:auto;padding-bottom:6px;margin:10px 0;scroll-snap-type:x mandatory}
.stage{min-width:132px;border:1px solid var(--line);border-radius:16px;padding:10px;background:#f8fbff;text-align:center;font-size:12px;font-weight:850;color:var(--muted);scroll-snap-align:start}
.stage.active{background:#dbeafe;color:#1d4ed8;border-color:#93c5fd}.stage.done{background:#dcfce7;color:#166534;border-color:#86efac}
.primaryAction{font-size:18px;padding:15px 18px;border-radius:18px;min-width:220px}
.scoreBox{border:1px solid var(--line);border-radius:18px;background:#fff;padding:14px;max-width:900px;margin:14px auto;text-align:left}.scoreBig{font-size:42px;font-weight:950}.scoreGood{color:var(--green)}.scoreOk{color:var(--orange)}.scoreBad{color:var(--red)}.wordLine{display:flex;gap:6px;flex-wrap:wrap}.word{border-radius:10px;padding:6px 8px;font-weight:850;font-size:13px;background:#e5e7eb}.word.ok{background:#dcfce7;color:#166534}.word.miss{background:#fee2e2;color:#991b1b}.word.extra{background:#ede9fe;color:#5b21b6}.word.sub{background:#fef3c7;color:#92400e}
.lessonLayout{display:grid;grid-template-columns:320px 1fr;gap:16px}.lessonList{background:white;border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:12px;max-height:calc(100vh - 130px);overflow:auto}.lessonItem{border:1px solid var(--line);background:#f8fbff;border-radius:16px;padding:12px;margin-bottom:10px;cursor:pointer}.lessonItem.active{border-color:var(--blue);background:#eff6ff}.lessonItem h3{font-size:14px;margin:6px 0}
.sentenceCard{border:1px solid var(--line);background:#fbfdff;border-radius:18px;padding:13px;margin-bottom:12px}.sentenceTop{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:10px}.num{width:36px;height:36px;border-radius:12px;background:#e8f0fb;display:grid;place-items:center;font-weight:950}.sentenceBody{display:grid;grid-template-columns:1fr 1fr;gap:10px}.sentenceMeta{display:grid;grid-template-columns:1fr 1fr 1fr 160px 160px;gap:9px;align-items:end}
.importArea textarea{min-height:280px;font-family:Consolas,monospace;font-size:13px}pre{white-space:pre-wrap;background:#0f172a;color:#e5e7eb;padding:16px;border-radius:18px;overflow:auto;font-size:12px}.empty{border:1px dashed var(--line);border-radius:18px;padding:24px;background:#fbfdff;color:var(--muted);text-align:center}.toast{position:fixed;right:18px;bottom:18px;z-index:99;background:#0f172a;color:white;border-radius:16px;padding:13px 16px;box-shadow:0 18px 45px rgba(15,23,42,.3);display:none;max-width:460px}.login{min-height:100vh;display:grid;place-items:center;padding:20px}.login .card{width:min(440px,100%)}
.bottomNav{display:none}.mobileTop{display:none}.menuGrid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.examQuestion{border:1px solid var(--line);background:#fbfdff;border-radius:18px;padding:15px;margin-bottom:10px}.stickyAction{position:sticky;bottom:78px;z-index:15;background:rgba(255,255,255,.94);border:1px solid var(--line);box-shadow:var(--shadow);border-radius:18px;padding:10px;margin-top:12px}
@media(max-width:1100px){.shell,.lessonLayout,.courseShell{grid-template-columns:1fr}.coursePanel{position:static}.stats,.grid3,.sentenceMeta{grid-template-columns:1fr 1fr}.lessonList{max-height:420px}}
@media(max-width:720px){
  body{padding-bottom:78px}.appTop{display:block;padding:10px 12px}.brand .logo{width:38px;height:38px;border-radius:13px}.brand h1{font-size:17px}.brand p{font-size:11px}.topActions{margin-top:8px;justify-content:flex-start}.topActions button{font-size:12px;padding:7px 9px}.shell{padding:10px;display:block}.side{display:none}.card{padding:14px;border-radius:18px;margin-bottom:12px}.viewHead{display:block}.viewHead .toolbar{margin-top:10px}.stats,.sideStats,.grid2,.grid3,.sentenceBody,.sentenceMeta,.menuGrid{grid-template-columns:1fr}.prompt{font-size:22px}.answer{font-size:23px;padding:12px}.toolbar button{flex:1}.trainerCard{padding:14px}.stage{min-width:112px;padding:8px;font-size:11px}.lessonDots{gap:4px}.dot{min-height:32px;border-radius:10px}.primaryAction{width:100%;min-width:0;font-size:16px}.mobileTop{display:block}.desktopOnly{display:none!important}.courseHeader{display:block;text-align:left}.bottomNav{position:fixed;bottom:0;left:0;right:0;z-index:50;display:grid;grid-template-columns:repeat(5,1fr);background:white;border-top:1px solid var(--line);box-shadow:0 -8px 28px rgba(15,23,42,.12)}.bottomNav button{border-radius:0;box-shadow:none;background:white;color:#334155;padding:9px 3px;font-size:11px;line-height:1.25}.bottomNav button.active{background:#eff6ff;color:#1d4ed8}.toast{left:10px;right:10px;bottom:88px;max-width:none}}