/* ============================================================
   Design tokens
   ============================================================ */
:root{
  --bg-0:#08111d;
  --bg-1:#0d1b2e;
  --bg-2:#122443;
  --surface: rgba(255,255,255,0.055);
  --surface-strong: rgba(255,255,255,0.09);
  --border: rgba(255,255,255,0.10);
  --text-0:#eef3f8;
  --text-1:#b7c5d6;
  --text-2:#7f93ab;
  --teal:#2dd4bf;
  --teal-strong:#14b8a6;
  --blue:#3b82f6;
  --indigo:#6366f1;
  --amber:#f5b942;
  --coral:#fb7d68;
  --radius-lg:22px;
  --radius-md:16px;
  --radius-sm:10px;
  --shadow-soft: 0 10px 40px rgba(3,10,20,0.45);
  --font-display: 'Fraunces', Georgia, serif;
  --font-body: 'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-arabic: 'Noto Naskh Arabic', 'Tahoma', sans-serif;
  --ease: cubic-bezier(.22,.9,.32,1);
}

[data-theme="light"]{
  --bg-0:#f4f8fb;
  --bg-1:#eaf1f6;
  --bg-2:#dfeaf1;
  --surface: rgba(255,255,255,0.7);
  --surface-strong: rgba(255,255,255,0.92);
  --border: rgba(15,40,60,0.10);
  --text-0:#0d2438;
  --text-1:#3c5568;
  --text-2:#6b8296;
  --shadow-soft: 0 10px 30px rgba(20,60,90,0.10);
}

*{ box-sizing:border-box; }
html,body{ margin:0; padding:0; height:100%; }
body{
  font-family: var(--font-body);
  background:
    radial-gradient(1100px 700px at 85% -10%, rgba(45,212,191,0.16), transparent 60%),
    radial-gradient(900px 600px at -10% 20%, rgba(99,102,241,0.14), transparent 55%),
    linear-gradient(180deg, var(--bg-0), var(--bg-1) 45%, var(--bg-2));
  color: var(--text-0);
  min-height:100%;
  transition: background .4s var(--ease), color .3s var(--ease);
  overflow-x:hidden;
}
[data-theme="light"] body{
  background:
    radial-gradient(1100px 700px at 85% -10%, rgba(45,212,191,0.20), transparent 60%),
    radial-gradient(900px 600px at -10% 20%, rgba(99,102,241,0.10), transparent 55%),
    linear-gradient(180deg, var(--bg-0), var(--bg-1) 45%, var(--bg-2));
}

::selection{ background: rgba(45,212,191,0.35); }
a{ color:inherit; }
button{ font-family:inherit; }
::-webkit-scrollbar{ width:10px; height:10px; }
::-webkit-scrollbar-thumb{ background: var(--border); border-radius:10px; }

.arabic{ font-family: var(--font-arabic); direction:rtl; }

/* ============================================================
   Layout shell
   ============================================================ */
#app{ min-height:100vh; display:flex; flex-direction:column; }

.topbar{
  position:sticky; top:0; z-index:40;
  display:flex; align-items:center; gap:16px;
  padding:14px 22px;
  background: var(--surface);
  backdrop-filter: blur(18px) saturate(140%);
  border-bottom:1px solid var(--border);
}
.brand{ display:flex; align-items:center; gap:10px; font-family:var(--font-display); font-size:1.25rem; font-weight:600; letter-spacing:.2px; margin-right:auto; }
.brand-mark{ width:34px; height:34px; border-radius:11px; display:grid; place-items:center;
  background: linear-gradient(135deg, var(--teal), var(--blue)); box-shadow: var(--shadow-soft); flex-shrink:0; }
.brand-mark svg{ width:19px; height:19px; }

.nav-tabs{ display:flex; gap:4px; background:var(--surface); border:1px solid var(--border); padding:4px; border-radius:999px; }
.nav-tab{
  border:none; background:transparent; color:var(--text-1); padding:9px 16px; border-radius:999px;
  font-size:.86rem; font-weight:600; cursor:pointer; transition: all .25s var(--ease); white-space:nowrap;
}
.nav-tab.active{ background: linear-gradient(135deg, var(--teal), var(--blue)); color:#04141c; box-shadow:0 4px 16px rgba(45,212,191,.25); }
.nav-tab:hover:not(.active){ color:var(--text-0); background:var(--surface-strong); }

.icon-btn{
  width:40px; height:40px; border-radius:12px; border:1px solid var(--border); background:var(--surface);
  color:var(--text-1); display:grid; place-items:center; cursor:pointer; transition: all .2s var(--ease); flex-shrink:0;
}
.icon-btn:hover{ color:var(--text-0); background:var(--surface-strong); transform:translateY(-1px); }
.icon-btn svg{ width:18px; height:18px; }

main{ flex:1; width:100%; max-width:1180px; margin:0 auto; padding:28px 22px 90px; }

@media (max-width: 860px){
  .topbar{ gap:10px; padding:12px 14px; flex-wrap:wrap; }
  .nav-tabs{ order:3; width:100%; overflow-x:auto; }
  main{ padding:18px 14px 100px; }
}

/* ============================================================
   Generic components
   ============================================================ */
.card{
  background: var(--surface); border:1px solid var(--border); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft); backdrop-filter: blur(14px);
}
.section-title{ font-family:var(--font-display); font-size:1.5rem; font-weight:600; margin:0 0 4px; }
.section-sub{ color:var(--text-1); font-size:.92rem; margin:0 0 18px; }

.btn{
  border:none; cursor:pointer; font-weight:700; font-size:.88rem; border-radius:999px; padding:11px 20px;
  display:inline-flex; align-items:center; gap:8px; transition: transform .2s var(--ease), box-shadow .2s var(--ease);
}
.btn-primary{ background:linear-gradient(135deg, var(--teal), var(--blue)); color:#04141c; box-shadow:0 8px 22px rgba(45,212,191,.28); }
.btn-primary:hover{ transform:translateY(-2px); box-shadow:0 12px 26px rgba(45,212,191,.35); }
.btn-ghost{ background:var(--surface); border:1px solid var(--border); color:var(--text-0); }
.btn-ghost:hover{ background:var(--surface-strong); }
.btn-sm{ padding:7px 14px; font-size:.78rem; }
.btn:disabled{ opacity:.4; cursor:not-allowed; transform:none !important; }

.pill{ display:inline-flex; align-items:center; gap:6px; font-size:.72rem; font-weight:700; padding:4px 10px; border-radius:999px; background:var(--surface-strong); border:1px solid var(--border); color:var(--text-1); text-transform:uppercase; letter-spacing:.04em; }
.pill.level-A0{ color:#7fe7c4; }
.pill.level-A1{ color:#7fc4e7; }
.pill.level-A2{ color:#e7b47f; }

/* ============================================================
   Dashboard
   ============================================================ */
.dash-hero{ padding:30px 32px; margin-bottom:22px; position:relative; overflow:hidden; }
.dash-hero::after{ content:""; position:absolute; inset:0; background: radial-gradient(500px 260px at 90% 0%, rgba(45,212,191,.20), transparent 70%); pointer-events:none; }
.dash-hero h1{ font-family:var(--font-display); font-size:2rem; margin:0 0 6px; font-weight:600; }
.dash-hero p{ color:var(--text-1); margin:0 0 20px; max-width:520px; }

.stat-grid{ display:grid; grid-template-columns:repeat(auto-fit, minmax(150px,1fr)); gap:14px; margin-bottom:22px; }
.stat-card{ padding:18px 20px; }
.stat-num{ font-family:var(--font-display); font-size:1.9rem; font-weight:600; }
.stat-label{ color:var(--text-2); font-size:.78rem; text-transform:uppercase; letter-spacing:.05em; margin-top:2px; }

.progress-track{ height:10px; border-radius:999px; background:var(--surface-strong); overflow:hidden; border:1px solid var(--border); }
.progress-fill{ height:100%; border-radius:999px; background:linear-gradient(90deg, var(--teal), var(--blue)); transition:width .6s var(--ease); }

.continue-row{ display:flex; align-items:center; gap:16px; flex-wrap:wrap; }

/* ============================================================
   Lessons grid
   ============================================================ */
.lesson-grid{ display:grid; grid-template-columns:repeat(auto-fill, minmax(240px,1fr)); gap:16px; }
.lesson-card{ padding:20px; cursor:pointer; transition: transform .25s var(--ease), border-color .25s; position:relative; }
.lesson-card:hover{ transform:translateY(-4px); border-color: rgba(45,212,191,.4); }
.lesson-num{ font-family:var(--font-display); font-size:.8rem; color:var(--text-2); margin-bottom:8px; }
.lesson-card h3{ margin:2px 0 8px; font-size:1.08rem; font-family:var(--font-display); font-weight:600; }
.lesson-meta{ display:flex; gap:8px; align-items:center; margin-bottom:12px; flex-wrap:wrap; }
.lesson-progress-ring{ position:absolute; top:16px; right:16px; }
.lesson-obj{ color:var(--text-1); font-size:.84rem; line-height:1.45; margin:0 0 10px; }
.lesson-foot{ display:flex; justify-content:space-between; align-items:center; font-size:.78rem; color:var(--text-2); }

/* ============================================================
   Lesson detail
   ============================================================ */
.lesson-header{ display:flex; align-items:flex-start; justify-content:space-between; gap:16px; margin-bottom:18px; flex-wrap:wrap; }
.mode-switch{ display:flex; gap:6px; background:var(--surface); border:1px solid var(--border); padding:4px; border-radius:999px; flex-wrap:wrap; }
.mode-btn{ border:none; background:transparent; color:var(--text-1); padding:8px 14px; border-radius:999px; font-size:.8rem; font-weight:700; cursor:pointer; transition:.2s; }
.mode-btn.active{ background:var(--surface-strong); color:var(--teal); }

.sentence-card{ padding:20px 22px; margin-bottom:14px; }
.sentence-top{ display:flex; justify-content:space-between; align-items:flex-start; gap:14px; }
.sentence-en{ font-size:1.18rem; font-weight:600; margin:0 0 6px; }
.sentence-pron{ color:var(--amber); font-size:.95rem; margin:0 0 4px; direction:rtl; font-family:var(--font-arabic); }
.sentence-ar{ color:var(--text-1); font-size:1.05rem; direction:rtl; font-family:var(--font-arabic); }
.hidden-text{ filter:blur(6px); user-select:none; transition:filter .2s; }
.hidden-text:hover{ filter:blur(3px); }

.sentence-actions{ display:flex; gap:6px; flex-wrap:wrap; margin-top:14px; }
.tiny-btn{
  border:1px solid var(--border); background:var(--surface); color:var(--text-1); border-radius:10px;
  padding:7px 10px; font-size:.72rem; font-weight:700; cursor:pointer; display:inline-flex; align-items:center; gap:5px;
  transition: all .2s var(--ease);
}
.tiny-btn:hover{ background:var(--surface-strong); color:var(--text-0); }
.tiny-btn.on{ background: linear-gradient(135deg, var(--teal), var(--blue)); color:#04141c; border-color:transparent; }
.tiny-btn svg{ width:14px; height:14px; }

.status-dot{ width:10px; height:10px; border-radius:50%; flex-shrink:0; margin-top:5px; }
.status-new{ background: var(--text-2); }
.status-learning{ background: var(--amber); }
.status-learned{ background: var(--teal); }

/* ============================================================
   Flashcards
   ============================================================ */
.flash-wrap{ display:flex; flex-direction:column; align-items:center; gap:20px; padding:20px 0; }
.flash-card{
  width:100%; max-width:480px; min-height:260px; border-radius:24px; cursor:pointer; perspective:1200px;
}
.flash-inner{ position:relative; width:100%; height:260px; transition: transform .5s var(--ease); transform-style:preserve-3d; }
.flash-card.flipped .flash-inner{ transform: rotateY(180deg); }
.flash-face{
  position:absolute; inset:0; backface-visibility:hidden; border-radius:24px; border:1px solid var(--border);
  background:var(--surface-strong); display:flex; flex-direction:column; align-items:center; justify-content:center;
  padding:26px; text-align:center; box-shadow: var(--shadow-soft);
}
.flash-face.back{ transform: rotateY(180deg); gap:10px; }
.flash-face .big-en{ font-family:var(--font-display); font-size:1.6rem; font-weight:600; }
.flash-hint{ color:var(--text-2); font-size:.78rem; margin-top:10px; }
.flash-controls{ display:flex; gap:12px; }
.flash-progress{ color:var(--text-2); font-size:.82rem; }

/* ============================================================
   Quiz
   ============================================================ */
.quiz-wrap{ max-width:560px; margin:0 auto; padding:10px 0; }
.quiz-prompt{ text-align:center; margin-bottom:22px; }
.quiz-prompt .q-label{ color:var(--text-2); font-size:.78rem; text-transform:uppercase; letter-spacing:.06em; }
.quiz-prompt .q-main{ font-family:var(--font-display); font-size:1.5rem; font-weight:600; margin-top:6px; }
.quiz-options{ display:grid; gap:10px; }
.quiz-opt{
  text-align:left; padding:14px 16px; border-radius:14px; border:1px solid var(--border); background:var(--surface);
  cursor:pointer; font-size:.98rem; color:var(--text-0); transition: all .2s var(--ease); direction:rtl; font-family:var(--font-arabic);
}
.quiz-opt:hover{ background:var(--surface-strong); }
.quiz-opt.correct{ border-color: var(--teal); background: rgba(45,212,191,.15); }
.quiz-opt.wrong{ border-color: var(--coral); background: rgba(251,125,104,.15); }
.quiz-footer{ display:flex; justify-content:space-between; align-items:center; margin-top:20px; }
.quiz-score{ text-align:center; padding:40px 20px; }
.quiz-score .big-score{ font-family:var(--font-display); font-size:3rem; font-weight:700; background:linear-gradient(135deg, var(--teal), var(--blue)); -webkit-background-clip:text; background-clip:text; color:transparent; }

/* ============================================================
   Empty / search
   ============================================================ */
.empty-state{ text-align:center; padding:60px 20px; color:var(--text-1); }
.search-input-wrap{ position:relative; margin-bottom:20px; }
.search-input{
  width:100%; padding:14px 18px 14px 46px; border-radius:16px; border:1px solid var(--border);
  background:var(--surface); color:var(--text-0); font-size:.98rem; outline:none; transition:border-color .2s;
}
.search-input:focus{ border-color: var(--teal); }
.search-icon{ position:absolute; left:16px; top:50%; transform:translateY(-50%); color:var(--text-2); width:18px; height:18px; }

.result-list{ display:flex; flex-direction:column; gap:10px; }
.result-row{ padding:14px 18px; display:flex; justify-content:space-between; align-items:center; gap:12px; flex-wrap:wrap; }

/* ============================================================
   Toast
   ============================================================ */
.toast{
  position:fixed; bottom:24px; left:50%; transform:translateX(-50%) translateY(20px); opacity:0;
  background:var(--surface-strong); border:1px solid var(--border); backdrop-filter:blur(16px);
  padding:12px 20px; border-radius:14px; font-size:.86rem; font-weight:600; z-index:100;
  transition: all .35s var(--ease); pointer-events:none; box-shadow:var(--shadow-soft);
}
.toast.show{ opacity:1; transform:translateX(-50%) translateY(0); }

/* ============================================================
   Motion respect
   ============================================================ */
@media (prefers-reduced-motion: reduce){
  *{ transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }
}

/* Fonts (system fallback fine offline; loaded via CDN when online) */
@font-face{
  font-family:'Fraunces'; font-weight:500 700; font-display: swap;
  src: local('Georgia');
}