/* ── Variables ─────────────────────────────────────────────────────── */
:root {
  --black:    #0a0a0f;
  --dark:     #13131a;
  --border:   #2a2a38;
  --white:    #f5f0e8;
  --gold:     #f0c040;
  --red:      #e63946;
  --green:    #2dc653;
  --blue:     #4a90e2;
  --muted:    rgba(245,240,232,0.45);
  --der:      #4a90e2;
  --die:      #e25c5c;
  --das:      #5cb85c;
  --radius:   12px;
  --transition: 0.22s ease;
}

/* ── Reset ─────────────────────────────────────────────────────────── */
*{margin:0;padding:0;box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  background:var(--black);
  color:var(--white);
  font-family:'Noto Sans Bengali',sans-serif;
  min-height:100vh;
  overflow-x:hidden;
}

/* ── Typography ────────────────────────────────────────────────────── */
h1,h2,h3{font-family:'Playfair Display',serif;line-height:1.15;}
.mono{font-family:'Space Mono',monospace;}
.label{font-family:'Space Mono',monospace;font-size:.68rem;letter-spacing:3px;text-transform:uppercase;color:var(--gold);}

/* ── Layout ────────────────────────────────────────────────────────── */
.dl-page{min-height:100vh;display:flex;flex-direction:column;}
.container{max-width:1100px;margin:0 auto;padding:0 1.5rem;}

/* ── Buttons ───────────────────────────────────────────────────────── */
.btn{display:inline-flex;align-items:center;gap:.5rem;padding:.85rem 1.8rem;border-radius:6px;font-family:'Noto Sans Bengali',sans-serif;font-size:.95rem;font-weight:700;cursor:pointer;transition:all var(--transition);border:none;text-decoration:none;}
.btn-gold{background:var(--gold);color:var(--black);}
.btn-gold:hover{background:#ffdd66;transform:translateY(-2px);box-shadow:0 8px 24px rgba(240,192,64,.3);}
.btn-outline{background:transparent;color:var(--white);border:1.5px solid rgba(245,240,232,.25);}
.btn-outline:hover{border-color:var(--white);transform:translateY(-2px);}
.btn-red{background:var(--red);color:#fff;}
.btn-red:hover{background:#ff4455;}
.btn-green{background:var(--green);color:var(--black);}
.btn-green:hover{background:#44dd66;}
.btn-sm{padding:.55rem 1.1rem;font-size:.82rem;}
.btn:disabled{opacity:.4;cursor:not-allowed;transform:none !important;}

/* ══════════════════════════════════════════════════════════════════════
   NAV
══════════════════════════════════════════════════════════════════════ */
.dl-nav{
  position:sticky;top:0;z-index:200;
  background:rgba(10,10,15,.96);
  backdrop-filter:blur(20px);
  border-bottom:1px solid var(--border);
  height:56px;display:flex;align-items:center;
}
.dl-nav .container{display:flex;align-items:center;gap:.5rem;width:100%;overflow-x:auto;scrollbar-width:none;}
.dl-nav .container::-webkit-scrollbar{display:none;}
.nav-brand{font-family:'Playfair Display',serif;font-size:1.15rem;font-weight:700;color:var(--gold);white-space:nowrap;margin-right:1rem;text-decoration:none;}
.nav-link{padding:.4rem .75rem;font-size:.78rem;color:var(--muted);cursor:pointer;white-space:nowrap;transition:color var(--transition);font-family:'Space Mono',monospace;border-radius:6px;text-decoration:none;}
.nav-link:hover,.nav-link.active{color:var(--white);background:rgba(255,255,255,.06);}
.nav-user{margin-left:auto;display:flex;align-items:center;gap:.75rem;white-space:nowrap;}
.nav-streak{font-family:'Space Mono',monospace;font-size:.78rem;color:var(--gold);}
.nav-logout{font-size:.75rem;color:var(--muted);cursor:pointer;text-decoration:none;}
.nav-logout:hover{color:var(--red);}

/* ══════════════════════════════════════════════════════════════════════
   AUTH / ONBOARDING
══════════════════════════════════════════════════════════════════════ */
.auth-wrap{
  min-height:100vh;display:flex;align-items:center;justify-content:center;
  padding:2rem;
  background:radial-gradient(ellipse at 50% 0%, #1a1a2e 0%, var(--black) 70%);
}
.auth-box{
  background:var(--dark);
  border:1px solid var(--border);
  border-radius:20px;
  padding:3rem 2.5rem;
  width:100%;max-width:440px;
}
.auth-flag{display:flex;width:64px;height:12px;border-radius:3px;overflow:hidden;margin-bottom:1.5rem;}
.auth-flag div{flex:1;}
.f-black{background:#000;}.f-red{background:#e63946;}.f-gold{background:var(--gold);}
.auth-title{font-size:2rem;margin-bottom:.4rem;}
.auth-title span{color:var(--gold);}
.auth-sub{color:var(--muted);font-size:.9rem;margin-bottom:2rem;}
.form-group{margin-bottom:1.2rem;}
.form-group label{display:block;font-size:.8rem;color:var(--muted);margin-bottom:.4rem;font-family:'Space Mono',monospace;}
.form-input{
  width:100%;background:rgba(255,255,255,.04);
  border:1.5px solid var(--border);border-radius:8px;
  padding:.8rem 1rem;color:var(--white);font-size:.9rem;
  font-family:'Noto Sans Bengali',sans-serif;outline:none;
  transition:border-color var(--transition);
}
.form-input:focus{border-color:var(--gold);}
.form-input::placeholder{color:rgba(245,240,232,.25);}
.auth-divider{display:flex;align-items:center;gap:.8rem;margin:1.2rem 0;color:var(--muted);font-size:.78rem;}
.auth-divider::before,.auth-divider::after{content:'';flex:1;height:1px;background:var(--border);}
.auth-error{background:rgba(230,57,70,.12);border:1px solid rgba(230,57,70,.3);border-radius:8px;padding:.8rem 1rem;color:var(--red);font-size:.82rem;margin-bottom:1rem;display:none;}
.auth-tabs{display:flex;gap:0;margin-bottom:2rem;border:1px solid var(--border);border-radius:8px;overflow:hidden;}
.auth-tab{flex:1;padding:.75rem;text-align:center;cursor:pointer;font-size:.85rem;font-family:'Space Mono',monospace;color:var(--muted);transition:all var(--transition);}
.auth-tab.active{background:var(--gold);color:var(--black);font-weight:700;}

/* ── Onboarding Steps ─────────────────────────────────────────────── */
.onboard-step{display:none;}
.onboard-step.active{display:block;}
.onboard-progress{display:flex;gap:.5rem;margin-bottom:2rem;}
.ob-dot{flex:1;height:4px;border-radius:2px;background:var(--border);transition:background .3s;}
.ob-dot.done{background:var(--gold);}
.ob-step-label{font-family:'Space Mono',monospace;font-size:.68rem;letter-spacing:2px;color:var(--gold);margin-bottom:.5rem;text-transform:uppercase;}
.ob-question{font-size:1.5rem;font-weight:700;margin-bottom:.4rem;}
.ob-sub{color:var(--muted);font-size:.9rem;margin-bottom:1.5rem;}
.ob-options{display:grid;gap:.7rem;}
.ob-option{
  background:rgba(255,255,255,.03);
  border:1.5px solid var(--border);
  border-radius:10px;padding:1rem 1.2rem;
  cursor:pointer;transition:all var(--transition);
  display:flex;align-items:center;gap:.8rem;
}
.ob-option:hover{border-color:rgba(240,192,64,.4);background:rgba(240,192,64,.05);}
.ob-option.selected{border-color:var(--gold);background:rgba(240,192,64,.1);}
.ob-option-icon{font-size:1.4rem;}
.ob-option-text{font-size:.92rem;font-weight:600;}
.ob-option-desc{font-size:.76rem;color:var(--muted);}

/* ══════════════════════════════════════════════════════════════════════
   DASHBOARD
══════════════════════════════════════════════════════════════════════ */
.dashboard-hero{
  padding:3rem 0 2rem;
  background:radial-gradient(ellipse at 50% -20%, #1a1a2e 0%, var(--black) 60%);
}
.dashboard-hero h1{font-size:clamp(1.8rem,4vw,2.8rem);margin-bottom:.4rem;}
.dashboard-hero h1 span{color:var(--gold);}
.dashboard-hero p{color:var(--muted);font-size:1rem;}

/* Level selector tabs */
.level-tabs{display:flex;gap:.5rem;margin:2rem 0 1rem;}
.level-tab{
  padding:.55rem 1.2rem;border-radius:20px;
  font-family:'Space Mono',monospace;font-size:.78rem;font-weight:700;
  cursor:pointer;transition:all var(--transition);
  border:1.5px solid var(--border);color:var(--muted);background:transparent;
}
.level-tab:hover{border-color:var(--gold);color:var(--gold);}
.level-tab.active{background:var(--gold);border-color:var(--gold);color:var(--black);}

/* Streak widget */
.streak-widget{
  background:var(--dark);border:1px solid var(--border);border-radius:16px;
  padding:1.5rem;display:flex;align-items:center;gap:1.5rem;margin-bottom:2rem;
}
.streak-flame{font-size:2.5rem;animation:pulse 2s infinite;}
.streak-num{font-family:'Playfair Display',serif;font-size:2.5rem;font-weight:900;color:var(--gold);line-height:1;}
.streak-lbl{font-size:.75rem;color:var(--muted);font-family:'Space Mono',monospace;}
.streak-days{display:flex;gap:.4rem;margin-top:.7rem;}
.streak-day{width:32px;height:32px;border-radius:50%;border:2px solid var(--border);display:flex;align-items:center;justify-content:center;font-size:.62rem;font-family:'Space Mono',monospace;color:var(--muted);}
.streak-day.done{background:var(--gold);border-color:var(--gold);color:var(--black);font-weight:700;}
.streak-day.today{border-color:var(--gold);color:var(--gold);}

/* Progress bar */
.xp-bar-wrap{flex:1;}
.xp-bar-label{font-size:.78rem;color:var(--muted);margin-bottom:.5rem;}
.xp-bar-track{background:var(--border);border-radius:6px;height:8px;overflow:hidden;}
.xp-bar-fill{background:var(--gold);height:100%;border-radius:6px;transition:width .6s ease;}

/* Lesson grid */
.lessons-grid{display:grid;gap:1rem;}
.lesson-card{
  background:var(--dark);border:1px solid var(--border);border-radius:var(--radius);
  padding:1.5rem;display:flex;align-items:center;gap:1.2rem;
  cursor:pointer;transition:all var(--transition);position:relative;overflow:hidden;
  text-decoration:none;color:inherit;
}
.lesson-card::before{content:'';position:absolute;left:0;top:0;width:4px;height:100%;background:var(--border);transition:background .3s;}
.lesson-card.available::before{background:var(--gold);}
.lesson-card.passed::before{background:var(--green);}
.lesson-card:hover.available{transform:translateX(4px);border-color:rgba(240,192,64,.3);}
.lesson-card.locked{opacity:.45;cursor:not-allowed;}
.lesson-icon{font-size:2rem;min-width:48px;text-align:center;}
.lesson-info{flex:1;}
.lesson-title{font-size:1rem;font-weight:700;margin-bottom:.25rem;}
.lesson-desc{font-size:.8rem;color:var(--muted);}
.lesson-meta{display:flex;gap:.5rem;margin-top:.5rem;flex-wrap:wrap;}
.lesson-tag{font-family:'Space Mono',monospace;font-size:.65rem;padding:.2rem .6rem;border-radius:4px;background:rgba(255,255,255,.05);border:1px solid var(--border);color:var(--muted);}
.lesson-badge{
  font-family:'Space Mono',monospace;font-size:.72rem;font-weight:700;
  padding:.3rem .8rem;border-radius:20px;white-space:nowrap;
}
.lesson-badge.passed{background:rgba(45,198,83,.15);color:var(--green);border:1px solid var(--green);}
.lesson-badge.available{background:rgba(240,192,64,.15);color:var(--gold);border:1px solid var(--gold);}
.lesson-badge.locked{background:rgba(255,255,255,.05);color:var(--muted);border:1px solid var(--border);}

/* Parts progress in lesson card */
.parts-progress{display:flex;gap:.3rem;margin-top:.6rem;}
.part-dot{width:8px;height:8px;border-radius:50%;background:var(--border);}
.part-dot.done{background:var(--green);}
.part-dot.current{background:var(--gold);}

/* ══════════════════════════════════════════════════════════════════════
   LESSON PAGE
══════════════════════════════════════════════════════════════════════ */
.lesson-header{padding:2.5rem 0 1.5rem;border-bottom:1px solid var(--border);}
.lesson-level-badge{display:inline-flex;align-items:center;gap:.4rem;margin-bottom:.8rem;}
.back-link{font-size:.8rem;color:var(--muted);text-decoration:none;font-family:'Space Mono',monospace;display:inline-flex;align-items:center;gap:.4rem;margin-bottom:1rem;}
.back-link:hover{color:var(--white);}

/* Parts sidebar + content layout */
.lesson-layout{display:grid;grid-template-columns:280px 1fr;gap:2rem;padding:2rem 0;}
.parts-sidebar{position:sticky;top:72px;height:fit-content;}
.parts-sidebar-title{font-family:'Space Mono',monospace;font-size:.68rem;letter-spacing:2px;color:var(--gold);margin-bottom:.8rem;text-transform:uppercase;}
.part-item{
  display:flex;align-items:center;gap:.8rem;
  padding:.85rem 1rem;border-radius:10px;
  cursor:pointer;transition:all var(--transition);
  border:1px solid transparent;margin-bottom:.4rem;
}
.part-item:hover{background:rgba(255,255,255,.04);}
.part-item.active{background:rgba(240,192,64,.08);border-color:rgba(240,192,64,.25);}
.part-item.complete{opacity:.7;}
.part-circle{
  width:28px;height:28px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  font-size:.75rem;font-family:'Space Mono',monospace;font-weight:700;
  border:2px solid var(--border);color:var(--muted);flex-shrink:0;
}
.part-circle.done{background:var(--green);border-color:var(--green);color:var(--black);}
.part-circle.active{border-color:var(--gold);color:var(--gold);}
.part-name{font-size:.85rem;font-weight:600;}
.part-status{font-size:.68rem;color:var(--muted);font-family:'Space Mono',monospace;}
.pruefung-item{
  margin-top:.8rem;padding:.85rem 1rem;border-radius:10px;
  border:1px solid var(--border);cursor:pointer;
  transition:all var(--transition);
  background:rgba(240,192,64,.05);
}
.pruefung-item:hover{border-color:var(--gold);}
.pruefung-item.locked{opacity:.35;cursor:not-allowed;}

/* Content area */
.lesson-content-area{min-width:0;}
.part-content-card{
  background:var(--dark);border:1px solid var(--border);
  border-radius:16px;padding:2rem;margin-bottom:1.5rem;
}
.part-title-row{display:flex;justify-content:space-between;align-items:flex-start;margin-bottom:1.5rem;flex-wrap:wrap;gap:1rem;}
.part-title{font-size:1.4rem;font-weight:700;}

/* Alphabet grid */
.alpha-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(80px,1fr));gap:.6rem;}
.alpha-card{
  background:rgba(255,255,255,.03);border:1px solid var(--border);
  border-radius:10px;padding:.9rem .5rem;text-align:center;
  cursor:pointer;transition:all var(--transition);
}
.alpha-card:hover{border-color:var(--gold);transform:translateY(-2px);}
.alpha-char{font-family:'Playfair Display',serif;font-size:1.8rem;font-weight:700;}
.alpha-sound{font-size:.62rem;color:var(--muted);font-family:'Space Mono',monospace;margin-top:.2rem;}

/* Phrase cards */
.phrase-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:.8rem;}
.phrase-card{
  background:rgba(255,255,255,.02);border:1px solid var(--border);
  border-radius:10px;padding:1.2rem;transition:all var(--transition);cursor:pointer;position:relative;
}
.phrase-card:hover{border-color:rgba(240,192,64,.3);transform:translateY(-2px);}
.phrase-cat{font-size:.62rem;letter-spacing:2px;text-transform:uppercase;color:var(--gold);font-family:'Space Mono',monospace;margin-bottom:.5rem;}
.phrase-de{font-size:1rem;font-weight:700;margin-bottom:.2rem;}
.phrase-ph{font-size:.73rem;color:rgba(245,240,232,.3);font-style:italic;margin-bottom:.4rem;}
.phrase-tr{font-size:.82rem;color:var(--muted);}
.play-btn{
  position:absolute;top:1rem;right:1rem;
  width:30px;height:30px;border-radius:50%;
  background:rgba(240,192,64,.1);border:1px solid rgba(240,192,64,.3);
  color:var(--gold);display:flex;align-items:center;justify-content:center;
  font-size:.65rem;cursor:pointer;transition:all var(--transition);
}
.play-btn:hover{background:rgba(240,192,64,.25);}

/* Vocabulary table */
.vocab-table{width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;border:1px solid var(--border);}
.vocab-table th{background:rgba(240,192,64,.1);color:var(--gold);font-family:'Space Mono',monospace;font-size:.72rem;padding:.8rem 1rem;text-align:left;border-bottom:1px solid var(--border);}
.vocab-table td{padding:.8rem 1rem;font-size:.85rem;border-bottom:1px solid rgba(42,42,56,.5);background:var(--dark);}
.vocab-table tr:last-child td{border-bottom:none;}
.vocab-table tr:hover td{background:rgba(255,255,255,.02);}
.art-der{color:var(--der);font-weight:700;}
.art-die{color:var(--die);font-weight:700;}
.art-das{color:var(--das);font-weight:700;}

/* Grammar explanation */
.grammar-box{background:rgba(240,192,64,.06);border:1px solid rgba(240,192,64,.2);border-radius:12px;padding:1.5rem;margin-bottom:1.5rem;}
.grammar-box pre{white-space:pre-wrap;font-family:'Space Mono',monospace;font-size:.8rem;color:var(--muted);line-height:1.8;}
.examples-list{display:flex;flex-direction:column;gap:.7rem;margin-top:1rem;}
.example-item{background:rgba(255,255,255,.03);border:1px solid var(--border);border-radius:8px;padding:.9rem 1.1rem;}
.example-de{font-size:.95rem;font-weight:700;margin-bottom:.3rem;}
.example-tr{font-size:.82rem;color:var(--muted);}

/* Complete button */
.complete-btn-row{display:flex;justify-content:flex-end;gap:.8rem;margin-top:1.5rem;}
.complete-btn{
  background:rgba(45,198,83,.1);border:1.5px solid var(--green);
  color:var(--green);padding:.75rem 1.8rem;border-radius:8px;
  font-weight:700;font-size:.9rem;cursor:pointer;transition:all var(--transition);
  font-family:'Noto Sans Bengali',sans-serif;
}
.complete-btn:hover{background:rgba(45,198,83,.2);}
.complete-btn.done{background:rgba(45,198,83,.15);cursor:default;}

/* ══════════════════════════════════════════════════════════════════════
   QUIZ OVERLAY
══════════════════════════════════════════════════════════════════════ */
.quiz-overlay{
  position:fixed;inset:0;z-index:1000;
  background:rgba(10,10,15,.97);
  display:none;flex-direction:column;align-items:center;justify-content:center;
  padding:1.5rem;
  overflow-y:auto;
}
.quiz-overlay.active{display:flex;}
.quiz-box{
  background:var(--dark);border:1px solid var(--border);
  border-radius:20px;width:100%;max-width:620px;padding:2.5rem;
}
.quiz-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:2rem;}
.quiz-close{background:none;border:none;color:var(--muted);font-size:1.3rem;cursor:pointer;transition:color .2s;}
.quiz-close:hover{color:var(--red);}
.quiz-progress-bar{flex:1;height:6px;background:var(--border);border-radius:3px;margin:0 1rem;overflow:hidden;}
.quiz-progress-fill{height:100%;background:var(--gold);border-radius:3px;transition:width .4s ease;}
.quiz-q-num{font-family:'Space Mono',monospace;font-size:.75rem;color:var(--muted);white-space:nowrap;}

/* Result streak dots */
.quiz-streak{display:flex;gap:.35rem;margin-bottom:1.5rem;flex-wrap:wrap;}
.q-dot{width:26px;height:26px;border-radius:50%;background:var(--border);border:2px solid var(--border);display:flex;align-items:center;justify-content:center;font-size:.6rem;transition:all .3s;}
.q-dot.correct{background:var(--green);border-color:var(--green);color:var(--black);}
.q-dot.wrong{background:var(--red);border-color:var(--red);color:#fff;}
.q-dot.current{border-color:var(--gold);}

/* Question area */
.quiz-q-type{font-family:'Space Mono',monospace;font-size:.68rem;letter-spacing:2px;color:var(--gold);margin-bottom:.8rem;}
.quiz-question{font-family:'Playfair Display',serif;font-size:1.8rem;font-weight:700;margin-bottom:.5rem;}
.quiz-sub{color:var(--muted);font-size:.85rem;margin-bottom:1.8rem;font-family:'Space Mono',monospace;}

/* MCQ options */
.quiz-options{display:grid;grid-template-columns:1fr 1fr;gap:.7rem;margin-bottom:1.5rem;}
.quiz-opt{
  padding:.9rem;background:rgba(255,255,255,.03);
  border:1.5px solid var(--border);border-radius:10px;
  cursor:pointer;text-align:center;font-size:1rem;font-weight:700;
  font-family:'Space Mono',monospace;transition:all .15s;color:var(--white);
}
.quiz-opt:hover:not(:disabled){border-color:var(--gold);background:rgba(240,192,64,.08);}
.quiz-opt.correct{border-color:var(--green);background:rgba(45,198,83,.15);color:var(--green);}
.quiz-opt.wrong{border-color:var(--red);background:rgba(230,57,70,.15);color:var(--red);}
.quiz-opt:disabled{cursor:not-allowed;}

/* Spelling / fill input */
.quiz-input-wrap{margin-bottom:1.5rem;}
.quiz-input{
  width:100%;background:rgba(255,255,255,.04);
  border:1.5px solid var(--border);border-radius:8px;
  padding:.9rem 1.1rem;color:var(--white);font-size:1.1rem;
  font-family:'Space Mono',monospace;outline:none;
  transition:border-color var(--transition);text-align:center;
}
.quiz-input:focus{border-color:var(--gold);}
.quiz-input.correct-input{border-color:var(--green);color:var(--green);}
.quiz-input.wrong-input{border-color:var(--red);color:var(--red);}

/* Feedback */
.quiz-feedback{
  min-height:2.2rem;font-size:.88rem;text-align:center;
  padding:.6rem;border-radius:8px;margin-bottom:1.2rem;
  font-family:'Space Mono',monospace;transition:all .2s;
}
.quiz-feedback.correct{background:rgba(45,198,83,.1);color:var(--green);border:1px solid rgba(45,198,83,.25);}
.quiz-feedback.wrong{background:rgba(230,57,70,.1);color:var(--red);border:1px solid rgba(230,57,70,.25);}

/* Quiz bottom row */
.quiz-actions{display:flex;justify-content:space-between;align-items:center;}
.quiz-score-label{font-family:'Space Mono',monospace;font-size:.78rem;color:var(--muted);}

/* Result screen */
.quiz-result{display:none;text-align:center;}
.quiz-result.show{display:block;}
.result-circle{
  width:120px;height:120px;border-radius:50%;
  display:inline-flex;align-items:center;justify-content:center;
  font-family:'Playfair Display',serif;font-size:2rem;font-weight:900;
  margin-bottom:1.5rem;
}
.result-circle.pass{background:rgba(45,198,83,.15);border:3px solid var(--green);color:var(--green);}
.result-circle.fail{background:rgba(230,57,70,.15);border:3px solid var(--red);color:var(--red);}
.result-title{font-size:1.5rem;font-weight:700;margin-bottom:.5rem;}
.result-msg{color:var(--muted);font-size:.9rem;margin-bottom:2rem;}

/* ══════════════════════════════════════════════════════════════════════
   FLASHCARD SECTION
══════════════════════════════════════════════════════════════════════ */
.flashcard-area{display:flex;flex-direction:column;align-items:center;gap:1.5rem;}
.flashcard-wrap{width:100%;max-width:420px;height:240px;perspective:1000px;cursor:pointer;}
.flashcard-inner{width:100%;height:100%;position:relative;transform-style:preserve-3d;transition:transform .6s cubic-bezier(.4,0,.2,1);}
.flashcard-inner.flipped{transform:rotateY(180deg);}
.fc-front,.fc-back{
  position:absolute;width:100%;height:100%;
  backface-visibility:hidden;border-radius:16px;
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  padding:2rem;text-align:center;
}
.fc-front{background:var(--dark);border:2px solid var(--border);}
.fc-back{background:linear-gradient(135deg,#1a1a2e,#16213e);border:2px solid var(--gold);transform:rotateY(180deg);}
.fc-art{font-family:'Space Mono',monospace;font-size:.78rem;padding:.2rem .8rem;border-radius:20px;margin-bottom:.6rem;}
.fc-word{font-family:'Playfair Display',serif;font-size:2.2rem;font-weight:700;}
.fc-hint{font-size:.78rem;color:rgba(245,240,232,.3);margin-top:.5rem;font-family:'Space Mono',monospace;}
.fc-meaning{font-size:1.1rem;color:var(--gold);font-weight:600;margin-bottom:.4rem;}
.fc-example{font-size:.82rem;color:var(--muted);font-style:italic;}
.fc-controls{display:flex;gap:.8rem;align-items:center;}
.fc-btn{padding:.65rem 1.3rem;border-radius:8px;border:1px solid var(--border);background:var(--dark);color:var(--white);cursor:pointer;font-family:'Space Mono',monospace;font-size:.78rem;transition:all .2s;}
.fc-btn:hover{border-color:var(--gold);color:var(--gold);}
.fc-btn.know{border-color:var(--green);color:var(--green);}
.fc-btn.know:hover{background:rgba(45,198,83,.1);}
.fc-progress{font-family:'Space Mono',monospace;font-size:.78rem;color:var(--muted);}

/* ══════════════════════════════════════════════════════════════════════
   GRAMMAR TABLE
══════════════════════════════════════════════════════════════════════ */
.grammar-table{width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;border:1px solid var(--border);}
.grammar-table th{background:rgba(240,192,64,.1);color:var(--gold);font-family:'Space Mono',monospace;font-size:.72rem;padding:.85rem 1.1rem;text-align:left;border-bottom:1px solid var(--border);}
.grammar-table td{padding:.85rem 1.1rem;font-size:.84rem;border-bottom:1px solid rgba(42,42,56,.5);background:var(--dark);}
.grammar-table tr:last-child td{border-bottom:none;}
.grammar-table tr:hover td{background:rgba(255,255,255,.02);}

/* ══════════════════════════════════════════════════════════════════════
   CHATBOT
══════════════════════════════════════════════════════════════════════ */
.chat-window{background:var(--dark);border:1px solid var(--border);border-radius:16px;overflow:hidden;max-width:640px;}
.chat-head{background:rgba(240,192,64,.08);border-bottom:1px solid var(--border);padding:.9rem 1.3rem;display:flex;align-items:center;gap:.7rem;}
.chat-avatar{width:34px;height:34px;border-radius:50%;background:var(--gold);display:flex;align-items:center;justify-content:center;font-size:.95rem;color:var(--black);}
.chat-name{font-weight:700;font-size:.88rem;}
.chat-status{font-size:.68rem;color:var(--green);font-family:'Space Mono',monospace;}
.chat-msgs{padding:1.3rem;display:flex;flex-direction:column;gap:.8rem;min-height:260px;max-height:320px;overflow-y:auto;}
.msg{max-width:80%;padding:.75rem 1rem;border-radius:12px;font-size:.86rem;line-height:1.5;}
.msg-bot{background:rgba(255,255,255,.05);border:1px solid var(--border);align-self:flex-start;border-bottom-left-radius:4px;}
.msg-user{background:rgba(240,192,64,.1);border:1px solid rgba(240,192,64,.25);align-self:flex-end;border-bottom-right-radius:4px;}
.chat-suggs{padding:0 1.3rem .8rem;display:flex;gap:.4rem;flex-wrap:wrap;}
.chat-sugg{background:rgba(255,255,255,.04);border:1px solid var(--border);padding:.3rem .7rem;border-radius:20px;font-size:.72rem;cursor:pointer;transition:all .2s;color:var(--muted);font-family:'Space Mono',monospace;}
.chat-sugg:hover{border-color:var(--gold);color:var(--gold);}
.chat-input-row{padding:.9rem 1.3rem;border-top:1px solid var(--border);display:flex;gap:.7rem;}
.chat-input-field{flex:1;background:rgba(255,255,255,.04);border:1px solid var(--border);border-radius:8px;padding:.65rem .9rem;color:var(--white);font-size:.86rem;font-family:'Noto Sans Bengali',sans-serif;outline:none;transition:border-color .2s;}
.chat-input-field:focus{border-color:var(--gold);}
.chat-send-btn{padding:.65rem 1.1rem;background:var(--gold);border:none;border-radius:8px;color:var(--black);font-weight:700;cursor:pointer;transition:all .2s;font-size:.86rem;}
.chat-send-btn:hover{background:#ffdd66;}

/* ══════════════════════════════════════════════════════════════════════
   PRONUNCIATION
══════════════════════════════════════════════════════════════════════ */
.pronun-box{background:var(--dark);border:1px solid var(--border);border-radius:16px;padding:2.2rem;max-width:620px;}
.pronun-target{font-family:'Playfair Display',serif;font-size:2rem;font-weight:700;margin-bottom:.3rem;}
.pronun-ph{font-size:.82rem;color:rgba(245,240,232,.3);font-style:italic;margin-bottom:.3rem;}
.pronun-tr{font-size:.85rem;color:var(--muted);}
.mic-btn{padding:.65rem 1.4rem;background:var(--red);border:none;border-radius:6px;color:#fff;font-weight:700;cursor:pointer;font-size:.88rem;transition:all .2s;}
.mic-btn:hover{background:#ff4455;}
.mic-btn.listening{background:#cc2233;animation:pulse .8s infinite;}
.pronun-result{border-radius:12px;padding:1.1rem;margin-top:1rem;display:none;}
.pronun-result.show{display:block;}

/* ══════════════════════════════════════════════════════════════════════
   LEADERBOARD
══════════════════════════════════════════════════════════════════════ */
.lb-row{display:flex;align-items:center;gap:1rem;padding:.85rem 1.4rem;border-bottom:1px solid rgba(42,42,56,.4);transition:background .2s;}
.lb-row:hover{background:rgba(255,255,255,.02);}
.lb-rank{font-family:'Playfair Display',serif;font-size:1.1rem;font-weight:900;width:24px;text-align:center;}
.lb-name{flex:1;font-weight:600;font-size:.88rem;}
.lb-streak{font-size:.7rem;color:var(--muted);font-family:'Space Mono',monospace;}
.lb-xp{font-family:'Space Mono',monospace;font-size:.83rem;color:var(--gold);font-weight:700;}

/* ══════════════════════════════════════════════════════════════════════
   BADGES
══════════════════════════════════════════════════════════════════════ */
.badges-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(140px,1fr));gap:.9rem;}
.badge-card{background:var(--dark);border:1px solid var(--border);border-radius:12px;padding:1.3rem .8rem;text-align:center;transition:all .2s;}
.badge-card.earned{border-color:var(--gold);background:rgba(240,192,64,.04);}
.badge-card:not(.earned){opacity:.35;filter:grayscale(1);}
.badge-icon{font-size:2.2rem;margin-bottom:.4rem;}
.badge-name{font-size:.78rem;font-weight:700;margin-bottom:.15rem;}
.badge-desc{font-size:.67rem;color:var(--muted);}

/* ══════════════════════════════════════════════════════════════════════
   DER/DIE/DAS CARDS
══════════════════════════════════════════════════════════════════════ */
.article-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:1rem;margin-top:1.5rem;}
.article-card{border-radius:12px;padding:1.8rem 1rem;text-align:center;cursor:pointer;transition:transform .2s;}
.article-card:hover{transform:scale(1.03);}
.article-card.der{background:rgba(74,144,226,.12);border:2px solid var(--der);}
.article-card.die{background:rgba(226,92,92,.12);border:2px solid var(--die);}
.article-card.das{background:rgba(92,184,92,.12);border:2px solid var(--das);}
.article-lbl{font-family:'Playfair Display',serif;font-size:2.2rem;font-weight:900;margin-bottom:.4rem;}
.der .article-lbl{color:var(--der);}
.die .article-lbl{color:var(--die);}
.das .article-lbl{color:var(--das);}
.article-meaning{font-size:.82rem;color:var(--muted);margin-bottom:.9rem;}
.article-examples span{display:block;padding:.2rem .5rem;border-radius:4px;margin:.2rem 0;background:rgba(255,255,255,.04);font-size:.78rem;}

/* ══════════════════════════════════════════════════════════════════════
   GUEST BANNER
══════════════════════════════════════════════════════════════════════ */
.guest-banner{
  background:rgba(240,192,64,.08);
  border-bottom:1px solid rgba(240,192,64,.2);
  padding:.6rem 1.5rem;
  text-align:center;
  font-size:.8rem;
  color:var(--muted);
}

/* ══════════════════════════════════════════════════════════════════════
   FLOATING CHAT WIDGET
══════════════════════════════════════════════════════════════════════ */
.chat-fab{
  position:fixed;bottom:1.5rem;right:1.5rem;
  width:56px;height:56px;border-radius:50%;
  background:var(--gold);border:none;cursor:pointer;z-index:400;
  display:flex;align-items:center;justify-content:center;
  font-size:1.5rem;
  box-shadow:0 4px 24px rgba(240,192,64,.45);
  transition:transform .2s,background .2s;
}
.chat-fab:hover{transform:scale(1.1);background:#ffdd66;}
.chat-fab.open{transform:rotate(10deg);}

.chat-panel{
  position:fixed;bottom:0;right:0;
  width:360px;height:520px;
  background:var(--dark);border:1px solid var(--border);
  border-radius:16px 16px 0 0;z-index:399;
  display:flex;flex-direction:column;
  transform:translateY(100%);
  transition:transform .3s cubic-bezier(.4,0,.2,1);
  box-shadow:0 -8px 40px rgba(0,0,0,.5);
}
.chat-panel.open{transform:translateY(0);}
.chat-panel-head{border-radius:16px 16px 0 0;}
.chat-panel .chat-msgs{flex:1;overflow-y:auto;}
.chat-close-btn{
  background:none;border:none;color:var(--muted);
  font-size:1.2rem;cursor:pointer;padding:.3rem;
  line-height:1;transition:color .2s;
}
.chat-close-btn:hover{color:var(--red);}

/* ══════════════════════════════════════════════════════════════════════
   FOOTER
══════════════════════════════════════════════════════════════════════ */
.dl-footer{border-top:1px solid var(--border);padding:2.5rem 1.5rem;text-align:center;color:rgba(245,240,232,.2);font-family:'Space Mono',monospace;font-size:.75rem;}
.dl-footer span{color:var(--gold);}

/* ══════════════════════════════════════════════════════════════════════
   SECTION SHARED
══════════════════════════════════════════════════════════════════════ */
.section{padding:4rem 0;}
.section + .section{border-top:1px solid var(--border);}
.section-label{font-family:'Space Mono',monospace;font-size:.68rem;letter-spacing:3px;text-transform:uppercase;color:var(--gold);margin-bottom:.6rem;}
.section-title{font-size:clamp(1.6rem,4vw,2.6rem);font-weight:700;margin-bottom:.8rem;line-height:1.1;}
.section-desc{color:var(--muted);font-size:.95rem;line-height:1.7;max-width:580px;margin-bottom:2rem;}
.divider{border:none;border-top:1px solid var(--border);margin:0;}

/* ══════════════════════════════════════════════════════════════════════
   ANIMATIONS
══════════════════════════════════════════════════════════════════════ */
@keyframes fadeUp{from{opacity:0;transform:translateY(24px);}to{opacity:1;transform:translateY(0);}}
@keyframes bounce{0%,100%{transform:translateX(-50%) translateY(0);}50%{transform:translateX(-50%) translateY(8px);}}
@keyframes pulse{0%,100%{transform:scale(1);}50%{transform:scale(1.08);}}
@keyframes spin{to{transform:rotate(360deg);}}
.fade-up{animation:fadeUp .6s ease both;}
.loading-spinner{width:32px;height:32px;border:3px solid var(--border);border-top-color:var(--gold);border-radius:50%;animation:spin .7s linear infinite;}

/* ══════════════════════════════════════════════════════════════════════
   RESPONSIVE — TABLET (≤ 768px)
══════════════════════════════════════════════════════════════════════ */
@media(max-width:768px){
  /* Nav */
  .nav-brand{font-size:1rem;}
  .nav-link{padding:.35rem .6rem;font-size:.72rem;}
  .nav-user{gap:.5rem;}

  /* Dashboard hero */
  .dashboard-hero{padding:2rem 0 1.5rem;}
  .dashboard-hero h1{font-size:1.6rem;}

  /* Level tabs — horizontal scroll */
  .level-tabs{overflow-x:auto;scrollbar-width:none;padding-bottom:.25rem;flex-wrap:nowrap;}
  .level-tabs::-webkit-scrollbar{display:none;}
  .level-tab{white-space:nowrap;flex-shrink:0;}

  /* Streak widget */
  .streak-widget{flex-wrap:wrap;gap:1rem;padding:1.2rem;}
  .streak-flame{font-size:2rem;}
  .streak-num{font-size:2rem;}
  .streak-days{flex-wrap:wrap;}
  .streak-day{width:28px;height:28px;font-size:.58rem;}

  /* Lesson layout — single column */
  .lesson-layout{grid-template-columns:1fr;gap:1rem;}
  .parts-sidebar{position:static;display:flex;flex-direction:column;}

  /* Parts list — horizontal scroll on mobile */
  .parts-list{display:flex;overflow-x:auto;gap:.4rem;scrollbar-width:none;padding-bottom:.3rem;}
  .parts-list::-webkit-scrollbar{display:none;}
  .part-item{flex-shrink:0;min-width:140px;}

  /* Article cards — 1 column */
  .article-cards{grid-template-columns:1fr;}
  .article-card{padding:1.3rem .8rem;}
  .article-lbl{font-size:1.8rem;}

  /* Quiz overlay — fullscreen */
  .quiz-overlay{padding:0;}
  .quiz-box{border-radius:0;border:none;padding:1.5rem 1.2rem;min-height:100vh;max-width:100%;}
  .quiz-options{grid-template-columns:1fr;}
  .quiz-question{font-size:1.4rem;}

  /* Flashcard */
  .flashcard-wrap{max-width:100%;}
  .fc-word{font-size:1.8rem;}

  /* Grammar/vocab table — horizontal scroll */
  .grammar-table-wrap,.vocab-table-wrap{overflow-x:auto;-webkit-overflow-scrolling:touch;}
  .grammar-table,.vocab-table{min-width:480px;}

  /* Chat */
  .chat-window{max-width:100%;}
  .chat-msgs{min-height:180px;max-height:240px;}

  /* Pronunciation */
  .pronun-box{max-width:100%;}
  .pronun-target{font-size:1.5rem;}

  /* Leaderboard */
  .leaderboard-wrap{grid-template-columns:1fr!important;}

  /* Badges */
  .badges-grid{grid-template-columns:repeat(auto-fill,minmax(110px,1fr));}

  /* Phrase grid */
  .phrase-grid{grid-template-columns:1fr;}

  /* Section shared */
  .section{padding:3rem 0;}

  /* Auth modal inside overlay */
  #authModal .auth-box{max-width:100%;margin:1rem;border-radius:16px;}
}

/* ══════════════════════════════════════════════════════════════════════
   RESPONSIVE — MOBILE (≤ 480px)
══════════════════════════════════════════════════════════════════════ */
@media(max-width:480px){
  /* Auth/onboarding box */
  .auth-box{padding:1.8rem 1.2rem;border-radius:14px;}
  .auth-title{font-size:1.6rem;}
  .ob-question{font-size:1.2rem;}

  /* Wrap — no side padding */
  .auth-wrap{padding:1rem;}

  /* Nav */
  .dl-nav{height:48px;}
  .nav-brand{font-size:.95rem;}
  .nav-link{display:none;}
  .nav-user{margin-left:auto;}

  /* Dashboard */
  .dashboard-hero{padding:1.5rem 0 1rem;}
  .dashboard-hero h1{font-size:1.35rem;}

  /* Lesson card */
  .lesson-card{padding:1.1rem;gap:.8rem;}
  .lesson-icon{font-size:1.5rem;min-width:36px;}
  .lesson-title{font-size:.9rem;}
  .lesson-desc{font-size:.73rem;}
  .lesson-badge{font-size:.65rem;padding:.25rem .6rem;}

  /* Quiz */
  .quiz-box{padding:1.2rem 1rem;}
  .quiz-question{font-size:1.2rem;}
  .quiz-sub{font-size:.78rem;}
  .quiz-opt{padding:.75rem .5rem;font-size:.88rem;}
  .result-circle{width:90px;height:90px;font-size:1.6rem;}

  /* Part items */
  .part-item{padding:.7rem .75rem;}
  .part-name{font-size:.78rem;}
  .part-circle{width:24px;height:24px;font-size:.65rem;}

  /* Flashcard */
  .flashcard-wrap{height:200px;}
  .fc-word{font-size:1.5rem;}

  /* Streak */
  .streak-widget{padding:1rem;}
  .xp-bar-wrap{width:100%;}

  /* Section */
  .section{padding:2.5rem 0;}
  .section-title{font-size:1.4rem;}

  /* Buttons row — stack on small */
  .complete-btn-row{flex-direction:column;}
  .complete-btn{width:100%;text-align:center;}

  /* Chat */
  .chat-msgs{min-height:140px;max-height:200px;}

  /* Pronunciation pills */
  .pronun-target{font-size:1.2rem;}

  /* Auth modal fullscreen on mobile */
  #authModal{align-items:flex-end;}
  #authModal .auth-box{border-radius:20px 20px 0 0;max-width:100%;margin:0;padding:2rem 1.5rem;}

  /* Floating chat — full width on mobile */
  .chat-panel{width:100%;height:65vh;border-radius:20px 20px 0 0;}
  .chat-fab{bottom:1rem;right:1rem;width:50px;height:50px;font-size:1.3rem;}
}