:root{
  --bg:#f1f5f9;
  --card:#ffffff;
  --ink:#1e293b;
  --muted:#64748b;
  --line:#e2e8f0;
  --brand:#6d28d9;
  --brand2:#4f46e5;
  --grad:linear-gradient(135deg,#6d28d9,#4f46e5 50%,#0891b2);
  --radius:18px;
  --shadow:0 10px 30px rgba(30,41,59,.10);
}
*{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%}
body{
  font-family:'Segoe UI',system-ui,-apple-system,'Helvetica Neue',Arial,sans-serif;
  color:var(--ink);
  background:var(--bg);
  -webkit-font-smoothing:antialiased;
}

/* ---------- buttons ---------- */
.btn{
  border:none;cursor:pointer;font-family:inherit;font-weight:600;
  border-radius:14px;transition:transform .12s ease,box-shadow .12s ease,opacity .12s;
}
.btn:active{transform:scale(.97)}
.btn-primary{background:var(--grad);color:#fff;padding:14px 22px;font-size:15px;box-shadow:0 8px 20px rgba(79,70,229,.35)}
.btn-primary:hover{box-shadow:0 12px 26px rgba(79,70,229,.45)}
.btn-lg{width:100%;font-size:16px;padding:16px}
.btn-quiz{background:#fff;color:#4f46e5;padding:14px 26px;font-size:15px;box-shadow:0 8px 20px rgba(0,0,0,.15)}
.btn-quiz:hover{box-shadow:0 10px 24px rgba(0,0,0,.2)}
.btn-ghost{background:transparent;color:#fff;border:2px solid rgba(255,255,255,.5);padding:10px 18px}
.btn-ghost:hover{background:rgba(255,255,255,.1)}
.btn-cyan{background:#0891b2;color:#fff;padding:12px 20px}

/* ---------- login ---------- */
.screen-login{
  min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px;
  background:linear-gradient(120deg,#0f172a 0%,#4f46e5 45%,#0891b2 100%);
  background-size:200% 200%;animation:flow 14s ease infinite;
}
@keyframes flow{0%{background-position:0% 50%}50%{background-position:100% 50%}100%{background-position:0% 50%}}
.login-card{
  background:#fff;border-radius:26px;padding:38px 32px;width:100%;max-width:430px;
  box-shadow:0 30px 60px rgba(0,0,0,.35);text-align:center;
}
.login-logo{font-size:56px;line-height:1}
.login-card h1{font-size:34px;font-weight:800;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent;margin:8px 0 4px}
.tagline{color:var(--muted);font-size:14px;margin-bottom:26px}
.field{display:block;text-align:left;margin-bottom:16px}
.field span{display:block;font-size:13px;font-weight:600;color:var(--muted);margin-bottom:6px}
.field input,.field select{
  width:100%;padding:13px 14px;border:2px solid var(--line);border-radius:12px;
  font-family:inherit;font-size:15px;background:#f8fafc;color:var(--ink);outline:none;
  transition:border .15s;
}
.field input:focus,.field select:focus{border-color:var(--brand)}
.login-error{color:#dc2626;font-size:13px;font-weight:600;margin-top:12px;min-height:18px}

/* ---------- app shell ---------- */
.app{min-height:100vh}
.topbar{
  position:sticky;top:0;z-index:50;display:flex;align-items:center;gap:12px;
  background:rgba(255,255,255,.92);backdrop-filter:blur(10px);
  padding:14px 18px;border-bottom:1px solid var(--line);
}
.topbar-title{flex:1;font-weight:700;font-size:17px;text-align:center}
.icon-btn{
  width:40px;height:40px;border-radius:50%;border:1px solid var(--line);background:#fff;
  font-size:18px;cursor:pointer;color:var(--ink);display:flex;align-items:center;justify-content:center;
}
.icon-btn:active{transform:scale(.93)}
.avatar{width:40px;height:40px;border-radius:50%;border:1px solid var(--line);background:var(--grad);color:#fff;font-size:18px;cursor:pointer}
main{padding:20px 18px 60px;max-width:860px;margin:0 auto}
body.fullbleed main{max-width:none;padding:0}

.view{display:none;animation:fade .25s ease}
.view.active{display:block}
@keyframes fade{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* ---------- home ---------- */
.welcome{
  display:flex;align-items:center;justify-content:space-between;gap:14px;
  background:var(--grad);color:#fff;border-radius:var(--radius);padding:22px;box-shadow:var(--shadow);
}
.welcome h2{font-size:22px;font-weight:800}
.welcome p{font-size:13px;opacity:.9}
.welcome-level{font-size:46px}
.stat-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:16px 0}
.stat-card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:12px;text-align:center}
.stat-card b{font-size:20px;display:block}
.stat-card span{font-size:11px;color:var(--muted)}
.section-title{font-size:17px;font-weight:700;margin:6px 0 14px}
.subject-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:14px}
.subject-card{
  background:var(--card);border-radius:var(--radius);border:1px solid var(--line);cursor:pointer;
  padding:18px;display:flex;align-items:center;gap:14px;box-shadow:0 4px 14px rgba(30,41,59,.06);
  transition:transform .15s ease,box-shadow .15s ease;
}
.subject-card:hover{transform:translateY(-3px);box-shadow:var(--shadow)}
.subject-icon{
  width:54px;height:54px;border-radius:14px;display:flex;align-items:center;justify-content:center;
  font-size:26px;color:#fff;flex-shrink:0;
}
.subject-card h4{font-size:15px;font-weight:700}
.subject-card small{font-size:12px;color:var(--muted);display:block;margin-top:2px}
.subject-progress{height:6px;background:var(--line);border-radius:6px;margin-top:8px;overflow:hidden}
.subject-progress i{display:block;height:100%;border-radius:6px;background:var(--ac,#4f46e5)}
.feature-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:14px;margin-top:22px}
.feature-card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);cursor:pointer;
  padding:18px;display:flex;gap:12px;align-items:center;text-align:left;box-shadow:var(--shadow);
  transition:transform .15s;
}
.feature-card:hover{transform:translateY(-3px)}
.feature-icon{font-size:32px}
.feature-card strong{font-size:14px;display:block}
.feature-card small{font-size:11px;color:var(--muted)}

.mega-btn{
  width:100%;display:flex;align-items:center;gap:16px;text-align:left;cursor:pointer;
  background:linear-gradient(135deg,#f59e0b,#ef4444);color:#fff;border:none;border-radius:var(--radius);
  padding:18px 20px;margin-bottom:20px;box-shadow:var(--shadow);transition:transform .15s;
  font-family:inherit;
}
.mega-btn:hover{transform:translateY(-2px)}
.mega-emoji{font-size:36px}
.mega-btn strong{font-size:16px;font-weight:800}
.mega-btn small{font-size:12px;opacity:.92}

.revision-btn{
  width:100%;display:flex;align-items:center;gap:14px;text-align:left;cursor:pointer;
  background:linear-gradient(135deg,#0ea5e9,#6366f1);color:#fff;border:none;border-radius:var(--radius);
  padding:16px 18px;margin-bottom:16px;box-shadow:var(--shadow);transition:transform .15s;font-family:inherit;
}
.revision-btn:hover{transform:translateY(-2px)}
.revision-btn span{font-size:30px}
.revision-btn strong{font-size:15px;font-weight:800}
.revision-btn small{font-size:12px;opacity:.92}

.resources-intro{color:var(--muted);font-size:13px;margin:2px 0 12px}
.resource-list{display:flex;flex-direction:column;gap:12px}
.resource-card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;
  display:flex;gap:14px;align-items:flex-start;box-shadow:0 4px 14px rgba(30,41,59,.06);
}
.resource-pic{font-size:34px;flex-shrink:0}
.resource-card h5{font-size:15px;font-weight:700;color:#4f46e5}
.resource-card p{font-size:13px;color:#475569;line-height:1.6;margin-top:4px}
.resource-card small{font-size:11px;color:var(--muted)}

/* ---------- chapters ---------- */
.subject-banner{
  border-radius:var(--radius);color:#fff;padding:18px;display:flex;align-items:center;gap:14px;margin-bottom:16px;
}
.subject-banner .subject-icon{background:rgba(255,255,255,.2)}
.subject-banner h3{font-size:18px;font-weight:800}
.subject-banner p{font-size:12px;opacity:.9}
.chapter-list{display:flex;flex-direction:column;gap:10px}
.chapter-item{
  background:var(--card);border:1px solid var(--line);border-radius:14px;padding:14px 16px;
  display:flex;align-items:center;gap:14px;cursor:pointer;transition:transform .12s,box-shadow .12s;
}
.chapter-item:hover{transform:translateX(4px);box-shadow:var(--shadow)}
.chapter-num{
  width:38px;height:38px;border-radius:10px;background:#eef2ff;color:#4f46e5;font-weight:700;
  display:flex;align-items:center;justify-content:center;font-size:14px;flex-shrink:0;
}
.chapter-item h5{font-size:14px;font-weight:600}
.chapter-item small{font-size:11px;color:var(--muted)}
.chapter-status{margin-left:auto;font-size:20px}

/* ---------- lesson (warm parchment background) ---------- */
.view-lesson{
  background:linear-gradient(160deg,#fdf6ec 0%,#fbeede 55%,#fdeee6 100%);
  margin:-20px -18px -60px;padding:26px 18px 70px;border-radius:0;
}
.lesson-head{max-width:860px;margin:0 auto 20px}
.lesson-chip{
  display:inline-block;background:#4f46e5;color:#fff;font-size:12px;font-weight:700;
  padding:5px 14px;border-radius:20px;margin-bottom:10px;
}
.lesson-chip.light{background:rgba(255,255,255,.18);color:#fff}
.lesson-head h2{font-size:26px;font-weight:800;color:#3b2f2f}
.lesson-intro{color:#6b5b4f;font-size:14px;margin-top:8px;line-height:1.6}
.def-card-list{max-width:860px;margin:0 auto;display:flex;flex-direction:column;gap:18px}
.def-card{
  background:#fff;border-radius:20px;padding:20px;box-shadow:0 12px 30px rgba(120,80,30,.12);
  display:flex;gap:18px;align-items:flex-start;border:1px solid #f3e2c9;
}
.def-pic{
  width:86px;height:86px;border-radius:16px;flex-shrink:0;
  background:linear-gradient(140deg,#ffedd5,#fde68a);display:flex;align-items:center;justify-content:center;font-size:46px;
}
.def-body{flex:1}
.def-tag{font-size:11px;font-weight:700;color:#b45309;text-transform:uppercase;letter-spacing:.5px}
.def-body h3{font-size:17px;font-weight:700;color:#3b2f2f;margin:2px 0 6px}
.def-body p{font-size:13.5px;color:#57534e;line-height:1.6}
.def-example{
  margin-top:10px;background:#fef9ef;border-left:4px solid #f59e0b;padding:10px 12px;border-radius:8px;
  font-size:13px;color:#7c5c1a;line-height:1.55;
}
.def-example b{color:#b45309}
.lesson-actions{max-width:860px;margin:26px auto 0;text-align:center}
.lesson-actions .btn-quiz{background:var(--grad);color:#fff}

/* ---------- quiz (dark indigo background) ---------- */
.view-quiz{
  background:linear-gradient(160deg,#1e1b4b 0%,#312e81 50%,#3730a3 100%);
  margin:-20px -18px -60px;padding:26px 18px 70px;border-radius:0;color:#e0e7ff;
}
.quiz-head{max-width:860px;margin:0 auto 20px;text-align:center}
.quiz-head h2{font-size:24px;font-weight:800;color:#fff}
.quiz-sub{font-size:13px;color:#a5b4fc;margin-top:4px}
.quiz-body{max-width:860px;margin:0 auto;display:flex;flex-direction:column;gap:18px}
.q-card{background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.14);border-radius:18px;padding:18px;backdrop-filter:blur(4px)}
.q-label{font-size:12px;font-weight:700;color:#a5b4fc;text-transform:uppercase;letter-spacing:.6px}
.q-card h4{font-size:15px;font-weight:600;color:#fff;margin:6px 0 12px;line-height:1.5}
.opt{display:block;background:rgba(255,255,255,.06);border:2px solid rgba(255,255,255,.15);border-radius:12px;padding:11px 14px;margin-bottom:8px;cursor:pointer;font-size:13.5px;color:#e0e7ff;transition:border .12s,background .12s}
.opt:hover{border-color:#818cf8}
.opt input{margin-right:10px;accent-color:#6366f1}
.opt.sel{border-color:#6366f1;background:rgba(99,102,241,.2)}
.theory-area{width:100%;min-height:88px;background:#fff;color:#1e293b;border:none;border-radius:12px;padding:12px;font-family:inherit;font-size:13.5px;resize:vertical;outline:none}
.theory-area:focus{box-shadow:0 0 0 3px rgba(99,102,241,.5)}
.quiz-actions{max-width:860px;margin:24px auto 0;text-align:center}

/* quiz result */
.quiz-result{
  max-width:860px;margin:26px auto 0;background:#fff;border-radius:20px;padding:26px;color:var(--ink);
  box-shadow:var(--shadow);
}
.quiz-result h3{font-size:22px;font-weight:800;text-align:center}
.score-circle{
  width:120px;height:120px;border-radius:50%;margin:16px auto;display:flex;flex-direction:column;
  align-items:center;justify-content:center;color:#fff;font-weight:800;
}
.score-circle b{font-size:30px}
.score-circle span{font-size:12px;opacity:.9}
.result-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:14px 0}
.result-box{background:#f8fafc;border:1px solid var(--line);border-radius:14px;padding:14px;text-align:center}
.result-box b{font-size:18px;display:block}
.result-box span{font-size:12px;color:var(--muted)}
.review-item{background:#f8fafc;border:1px solid var(--line);border-radius:12px;padding:12px;margin-bottom:10px;font-size:13px}
.review-item .ok{color:#16a34a;font-weight:700}
.review-item .no{color:#dc2626;font-weight:700}

/* ---------- dictionary ---------- */
.dict-search input{
  width:100%;padding:14px 16px;border:2px solid var(--line);border-radius:14px;font-family:inherit;font-size:15px;background:#fff;outline:none;
}
.dict-search input:focus{border-color:var(--brand)}
.dict-filters{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0}
.dict-filter{background:#fff;border:1px solid var(--line);border-radius:20px;padding:7px 14px;font-size:12px;font-weight:600;cursor:pointer;color:var(--muted)}
.dict-filter.active{background:var(--grad);color:#fff;border-color:transparent}
.dict-list{display:flex;flex-direction:column;gap:10px}
.dict-count{color:var(--muted);font-size:13px;margin:2px 0 12px}
.dict-item{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:14px 16px}
.dict-head{display:flex;align-items:center;gap:10px}
.dict-item h5{font-size:15px;font-weight:700;color:#4f46e5}
.dict-type{
  background:#eef2ff;color:#4f46e5;font-size:10px;font-weight:700;text-transform:uppercase;
  letter-spacing:.5px;padding:3px 9px;border-radius:20px;line-height:1.4;
}
.dict-item p{font-size:13px;color:#475569;line-height:1.6;margin-top:5px}
.dict-example{margin-top:8px;font-size:12.5px;color:#7c5c1a;line-height:1.5}
.dict-example span{font-style:italic}
.dict-item small{font-size:11px;color:var(--muted)}
.dict-empty{text-align:center;color:var(--muted);padding:40px 0;font-size:14px}

/* ---------- games ---------- */
.games-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px}
.game-card{
  background:linear-gradient(140deg,#fef9c3,#fde68a);border-radius:var(--radius);padding:20px;cursor:pointer;
  box-shadow:var(--shadow);transition:transform .15s;border:1px solid #fde68a;
}
.game-card:nth-child(2){background:linear-gradient(140deg,#dcfce7,#bbf7d0)}
.game-card:nth-child(3){background:linear-gradient(140deg,#dbeafe,#bfdbfe)}
.game-card:nth-child(4){background:linear-gradient(140deg,#fce7f3,#fbcfe8)}
.game-card:nth-child(5){background:linear-gradient(140deg,#ede9fe,#ddd6fe)}
.game-card:hover{transform:translateY(-4px)}
.game-card .game-emoji{font-size:38px}
.game-card h4{font-size:16px;font-weight:700;margin:6px 0 4px}
.game-card p{font-size:12px;color:#475569}
.game-area{
  margin-top:20px;background:var(--card);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow);
}
.game-hud{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px}
.game-hud b{font-size:16px}
.game-hud span{font-size:13px;color:var(--muted)}
.game-question{font-size:24px;font-weight:800;text-align:center;margin:18px 0}
.game-options{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.game-option{
  background:#f8fafc;border:2px solid var(--line);border-radius:12px;padding:14px;font-size:16px;font-weight:600;cursor:pointer;font-family:inherit;
}
.game-option:hover{border-color:var(--brand)}
.game-option.ok{background:#dcfce7;border-color:#16a34a;color:#166534}
.game-option.bad{background:#fee2e2;border-color:#dc2626;color:#991b1b}
.game-answer-row{display:flex;gap:10px;justify-content:center;align-items:center;margin-top:16px}
.game-answer-row input{
  padding:12px 14px;border:2px solid var(--line);border-radius:12px;font-family:inherit;font-size:15px;width:220px;outline:none;
}
.game-answer-row input:focus{border-color:var(--brand)}
.game-feedback{text-align:center;font-size:14px;font-weight:600;margin-top:12px;min-height:20px}
.memory-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;max-width:360px;margin:0 auto}
.mem-cell{aspect-ratio:1;border-radius:12px;background:var(--grad);display:flex;align-items:center;justify-content:center;font-size:30px;cursor:pointer;color:transparent;user-select:none;transition:transform .15s}
.mem-cell.flip{background:#fff;border:2px solid var(--line);color:inherit}
.mem-cell.matched{background:#dcfce7;border:2px solid #16a34a;cursor:default}

.simon-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;max-width:300px;margin:0 auto}
.simon-btn{aspect-ratio:1;border-radius:18px;border:none;cursor:pointer;opacity:.55;transition:opacity .12s,transform .1s}
.simon-btn.on{opacity:1;transform:scale(1.04)}
.simon-btn.lit{opacity:1;box-shadow:0 0 0 6px rgba(255,255,255,.35)}
.simon-btn:disabled{cursor:default}
.tf-row{display:flex;gap:12px;justify-content:center;margin-top:14px}
.tf-btn{padding:14px 34px;font-size:17px;font-weight:800;border-radius:14px;border:2px solid var(--line);background:#f8fafc;cursor:pointer;font-family:inherit}
.tf-btn.ok{background:#dcfce7;border-color:#16a34a;color:#166534}
.tf-btn.bad{background:#fee2e2;border-color:#dc2626;color:#991b1b}
.riddle-card{text-align:center;padding:10px 0}
.riddle-card h4{font-size:17px;line-height:1.6}
.riddle-answer{color:#16a34a;font-weight:700;font-size:15px;margin-top:10px}
.riddle-actions{display:flex;gap:10px;justify-content:center;margin-top:12px;flex-wrap:wrap}
.riddle-actions .btn-ghost{color:#4f46e5;border-color:#4f46e5;padding:9px 18px}
.version-note{text-align:center;color:var(--muted);font-size:12px;margin-top:24px}

/* ---------- responsive ---------- */
@media (max-width:560px){
  .subject-grid{grid-template-columns:1fr 1fr}
  .feature-row{grid-template-columns:1fr}
  .result-grid{grid-template-columns:1fr}
  .game-options{grid-template-columns:1fr}
  .def-card{flex-direction:column}
  .def-pic{width:100%;height:90px}
}