/* ============================================================
   TenMinLangs – Design System & Styles
   Dark glassmorphism, vibrant accent colours, smooth animations
   ============================================================ */

/* ---------- Tokens ---------- */
:root {
  --bg: #07071a;
  --bg2: #0d0d2b;
  --surface: rgba(255,255,255,0.04);
  --surface-hover: rgba(255,255,255,0.08);
  --border: rgba(255,255,255,0.10);
  --border-strong: rgba(255,255,255,0.18);

  --accent: #7c6bff;
  --accent2: #ff6b9d;
  --accent3: #43e8d8;
  --accent4: #f9a825;

  --text: #f0f0ff;
  --text2: #a8a8cc;
  --text3: #6060a0;

  --danger: #ff4757;
  --success: #2ed573;
  --warning: #ffa502;

  --radius: 16px;
  --radius-sm: 8px;
  --radius-lg: 24px;
  --blur: 20px;

  --font: 'Inter', system-ui, sans-serif;
  --trans: 0.25s cubic-bezier(0.4,0,0.2,1);
}

/* ---------- Reset ---------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--font);
  background:var(--bg);
  color:var(--text);
  min-height:100vh;
  overflow-x:hidden;
  line-height:1.6;
}
body::before{
  content:'';
  position:fixed;inset:0;
  background:
    radial-gradient(ellipse 80% 60% at 10% 10%, rgba(124,107,255,0.18) 0%, transparent 60%),
    radial-gradient(ellipse 60% 80% at 90% 80%, rgba(255,107,157,0.12) 0%, transparent 60%),
    radial-gradient(ellipse 50% 50% at 50% 50%, rgba(67,232,216,0.06) 0%, transparent 70%);
  pointer-events:none;
  z-index:0;
}
#app{position:relative;z-index:1}
img,svg{display:block;max-width:100%}
button{cursor:pointer;font-family:inherit;border:none;background:none;color:inherit}
input{font-family:inherit;color:inherit}
a{color:inherit;text-decoration:none}

/* ---------- Glass ---------- */
.glass{
  background:var(--surface);
  border:1px solid var(--border);
  backdrop-filter:blur(var(--blur));
  -webkit-backdrop-filter:blur(var(--blur));
  border-radius:var(--radius);
}

/* ---------- Utility ---------- */
.hidden{display:none!important}
.page{display:none}
.page.active{display:flex}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:10px 22px;border-radius:var(--radius-sm);
  font-size:0.9rem;font-weight:600;
  transition:all var(--trans);
  position:relative;overflow:hidden;
  border:1px solid transparent;
}
.btn::after{
  content:'';position:absolute;inset:0;
  background:rgba(255,255,255,0);
  transition:background var(--trans);
}
.btn:hover::after{background:rgba(255,255,255,0.07)}
.btn:active{transform:scale(0.97)}

.btn-primary{
  background:linear-gradient(135deg,var(--accent),#9d5cff);
  color:#fff;
  box-shadow:0 4px 24px rgba(124,107,255,0.35);
}
.btn-primary:hover{box-shadow:0 6px 32px rgba(124,107,255,0.55);transform:translateY(-1px)}

.btn-outline{
  background:transparent;
  border-color:var(--border-strong);
  color:var(--text2);
}
.btn-outline:hover{border-color:var(--accent);color:var(--text)}

.btn-ghost{background:transparent;color:var(--text2)}
.btn-ghost:hover{color:var(--text)}

.btn-danger{
  background:linear-gradient(135deg,var(--danger),#c0392b);
  color:#fff;
  box-shadow:0 4px 20px rgba(255,71,87,0.3);
}
.btn-danger:hover{box-shadow:0 6px 28px rgba(255,71,87,0.5)}

.btn-danger-outline{
  background:transparent;
  border:1px solid rgba(255,71,87,0.35);
  color:var(--danger);
}
.btn-danger-outline:hover{background:rgba(255,71,87,0.1)}

.btn-full{width:100%}
.btn-lg{padding:14px 32px;font-size:1rem}
.btn-sm{padding:7px 14px;font-size:0.8rem}

.icon-btn{
  width:36px;height:36px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  font-size:1rem;
  background:var(--surface);border:1px solid var(--border);
  transition:all var(--trans);
}
.icon-btn:hover{background:var(--surface-hover);border-color:var(--border-strong)}

/* ---------- Auth Page ---------- */
#page-auth{
  min-height:100vh;
  align-items:center;justify-content:center;
  padding:24px;
}
.auth-bg{position:fixed;inset:0;pointer-events:none;overflow:hidden;z-index:-1}
.auth-orb{
  position:absolute;border-radius:50%;
  filter:blur(80px);opacity:0.5;
  animation:float 8s ease-in-out infinite;
}
.orb-1{width:500px;height:500px;background:rgba(124,107,255,0.3);top:-100px;left:-100px;animation-delay:0s}
.orb-2{width:400px;height:400px;background:rgba(255,107,157,0.2);bottom:-80px;right:-80px;animation-delay:-3s}
.orb-3{width:300px;height:300px;background:rgba(67,232,216,0.15);top:50%;left:50%;transform:translate(-50%,-50%);animation-delay:-5s}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-20px)}}

.auth-card{
  width:100%;max-width:420px;
  padding:40px 36px;
  animation:slideUp 0.5s ease both;
}
@keyframes slideUp{from{opacity:0;transform:translateY(24px)}to{opacity:1;transform:translateY(0)}}

.auth-logo{text-align:center;margin-bottom:32px}
.logo-icon{font-size:2.5rem;display:block;margin-bottom:8px}
.logo-title{font-size:1.8rem;font-weight:800;letter-spacing:-0.02em;
  background:linear-gradient(135deg,var(--accent),var(--accent2));
  -webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.logo-sub{color:var(--text2);font-size:0.85rem;margin-top:4px}

.auth-form{display:flex;flex-direction:column;gap:16px}
.form-group{display:flex;flex-direction:column;gap:6px}
.form-group label{font-size:0.8rem;font-weight:600;color:var(--text2);letter-spacing:0.05em;text-transform:uppercase}
.input-wrapper{position:relative;display:flex;align-items:center}
.input-wrapper input{
  width:100%;padding:12px 44px 12px 16px;
  background:rgba(255,255,255,0.06);
  border:1px solid var(--border);border-radius:var(--radius-sm);
  color:var(--text);font-size:0.95rem;
  transition:border-color var(--trans),box-shadow var(--trans);
  outline:none;
}
.input-wrapper input:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(124,107,255,0.2)}
.input-wrapper .icon-btn{position:absolute;right:6px;font-size:0.9rem}
.error-msg{color:var(--danger);font-size:0.85rem;padding:8px 12px;background:rgba(255,71,87,0.12);border-radius:var(--radius-sm)}
.auth-footer{text-align:center;color:var(--text3);font-size:0.78rem;margin-top:20px}

/* ---------- Navbar ---------- */
.navbar{
  position:fixed;bottom:0;left:0;right:0;
  display:flex;align-items:center;justify-content:space-between;
  padding:8px 16px;
  border-radius:var(--radius-lg) var(--radius-lg) 0 0;
  border-bottom:none;
  z-index:100;
}
.nav-brand{display:flex;align-items:center;gap:8px;font-weight:700;font-size:0.9rem}
.logo-icon-sm{font-size:1.2rem}
@media(max-width:600px){.brand-text{display:none}}
.nav-links{display:flex;gap:4px}
.nav-btn{
  display:flex;flex-direction:column;align-items:center;gap:2px;
  padding:6px 14px;border-radius:var(--radius-sm);
  font-size:0.7rem;font-weight:600;color:var(--text2);
  transition:all var(--trans);
}
.nav-btn .nav-icon{font-size:1.1rem}
.nav-btn:hover,.nav-btn.active{color:var(--text);background:var(--surface-hover)}
.nav-btn.active{color:var(--accent)}
.nav-actions{display:flex;align-items:center;gap:8px}
.sync-indicator{display:flex;align-items:center;gap:6px;font-size:0.75rem;color:var(--text2)}
.sync-dot{width:8px;height:8px;border-radius:50%;background:var(--success);transition:background var(--trans)}
.sync-indicator.syncing .sync-dot{background:var(--warning);animation:pulse 1s infinite}
.sync-indicator.error .sync-dot{background:var(--danger)}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:0.3}}

/* ---------- Main content area ---------- */
#main-app{padding-bottom:80px;min-height:100vh}
.page-inner{
  display:none;padding:24px 20px;
  max-width:700px;margin:0 auto;
  animation:fadeIn 0.3s ease both;
}
.page-inner.active{display:block}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}

.page-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:24px;flex-wrap:wrap;gap:12px}
.page-title{font-size:1.5rem;font-weight:800;letter-spacing:-0.02em}
.header-actions{display:flex;gap:8px;flex-wrap:wrap}
.section-title{font-size:1rem;font-weight:700;color:var(--text2);margin:24px 0 12px;text-transform:uppercase;letter-spacing:0.06em}

/* ---------- Streak ---------- */
.streak-badge{
  display:flex;align-items:center;gap:6px;
  padding:6px 14px;border-radius:20px;
  background:linear-gradient(135deg,rgba(249,168,37,0.15),rgba(249,168,37,0.05));
  border:1px solid rgba(249,168,37,0.25);
  font-size:0.9rem;font-weight:700;
}
.streak-fire{font-size:1.1rem}
#streak-count{color:var(--accent4);font-size:1.1rem}
.streak-label{color:var(--text2);font-size:0.8rem}

/* ---------- Dashboard Hero ---------- */
.dashboard-hero{
  padding:28px;display:flex;
  align-items:center;justify-content:space-between;
  gap:20px;margin-bottom:8px;
  background:linear-gradient(135deg,rgba(124,107,255,0.1),rgba(255,107,157,0.07));
}
.hero-content{flex:1}
.hero-content h3{font-size:1.3rem;font-weight:700;margin-bottom:6px}
.hero-content p{color:var(--text2);margin-bottom:20px;font-size:0.9rem}
.hero-visual{flex-shrink:0}
.hero-clock{width:90px;height:90px}
.clock-svg{width:100%;height:100%;transform:rotate(-90deg)}
.clock-bg{fill:none;stroke:rgba(255,255,255,0.07);stroke-width:8}
.clock-progress{
  fill:none;stroke:var(--accent);stroke-width:8;
  stroke-dasharray:283;stroke-dashoffset:0;
  stroke-linecap:round;transition:stroke-dashoffset 1s ease;
}
.clock-inner{
  position:absolute;inset:0;display:flex;flex-direction:column;
  align-items:center;justify-content:center;
}
.clock-ring{position:relative;width:90px;height:90px}
.clock-time{font-size:1.6rem;font-weight:800;line-height:1}
.clock-unit{font-size:0.7rem;color:var(--text2)}

/* ---------- Language Cards ---------- */
.lang-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:14px}
.lang-card{
  background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius);padding:18px;
  cursor:pointer;transition:all var(--trans);
  position:relative;overflow:hidden;
}
.lang-card::before{
  content:'';position:absolute;top:0;left:0;right:0;height:3px;
  background:linear-gradient(90deg,var(--accent),var(--accent2));
  transform:scaleX(0);transform-origin:left;transition:transform var(--trans);
}
.lang-card:hover{transform:translateY(-3px);border-color:var(--border-strong);box-shadow:0 8px 32px rgba(0,0,0,0.3)}
.lang-card:hover::before{transform:scaleX(1)}
.lang-flag{font-size:2rem;margin-bottom:10px}
.lang-name{font-weight:700;font-size:1rem;margin-bottom:4px}
.lang-unit{color:var(--text2);font-size:0.8rem;margin-bottom:12px}
.lang-progress-bar{height:4px;background:rgba(255,255,255,0.07);border-radius:2px;overflow:hidden}
.lang-progress-fill{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2));border-radius:2px;transition:width 0.8s ease}

/* ---------- Session ---------- */
.session-idle{
  display:flex;flex-direction:column;align-items:center;
  justify-content:center;text-align:center;
  min-height:60vh;gap:12px;color:var(--text2);
}
.session-idle-icon{font-size:3rem;margin-bottom:8px}
.unit-study{padding:0}
.session-header{
  display:flex;align-items:center;justify-content:space-between;
  padding:16px 20px;gap:12px;
  background:var(--surface);border-bottom:1px solid var(--border);
  position:sticky;top:0;z-index:10;
}
.session-progress{display:flex;flex-direction:column;gap:4px;flex:1;align-items:center}
.session-progress-bar{width:100%;max-width:200px;height:6px;background:rgba(255,255,255,0.08);border-radius:3px;overflow:hidden}
.session-progress-fill{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2));border-radius:3px;transition:width 0.4s ease}
#session-progress-text{font-size:0.75rem;color:var(--text2)}
.session-lang-badge{font-size:0.85rem;font-weight:600;color:var(--text2)}

/* Vocab Card (flip) */
.study-phase{padding:24px 20px;max-width:500px;margin:0 auto}
.flip-card-wrapper{perspective:1000px;margin-bottom:24px}
.flip-card{
  position:relative;height:320px;
  transform-style:preserve-3d;transition:transform 0.5s ease;
  cursor:pointer;
}
.flip-card.flipped{transform:rotateY(180deg)}
.flip-card-front,.flip-card-back{
  position:absolute;inset:0;
  backface-visibility:hidden;-webkit-backface-visibility:hidden;
  border-radius:var(--radius);padding:24px;
  display:flex;flex-direction:column;align-items:center;justify-content:center;gap:8px;
}
.flip-card-back{transform:rotateY(180deg)}
.word-counter{position:absolute;top:14px;right:14px;font-size:0.75rem;color:var(--text3)}
.native-word{font-size:2.5rem;font-weight:700;text-align:center;line-height:1.2}
.romanisation{color:var(--accent3);font-size:1rem;font-style:italic}
.audio-btn{
  width:44px;height:44px;border-radius:50%;font-size:1.3rem;
  background:rgba(124,107,255,0.15);border:1px solid rgba(124,107,255,0.3);
  transition:all var(--trans);margin-top:4px;
}
.audio-btn:hover{background:rgba(124,107,255,0.3);transform:scale(1.1)}
.flip-hint{font-size:0.78rem;color:var(--text3);margin-top:8px}
.english-word{font-size:1.5rem;font-weight:700;text-align:center}
.word-notes{font-size:0.85rem;color:var(--text2);text-align:center;font-style:italic}
.card-actions{display:flex;gap:12px;margin-top:16px}

/* Quiz */
.quiz-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}
.quiz-score-display{display:flex;align-items:center;gap:6px;font-size:1.1rem;font-weight:700}
#quiz-q-counter{font-size:0.85rem;color:var(--text2)}
.quiz-card{padding:24px}
.quiz-question{font-size:1.05rem;font-weight:600;margin-bottom:20px;line-height:1.5}
.quiz-choices{display:flex;flex-direction:column;gap:10px}
.quiz-choice{
  padding:14px 18px;border-radius:var(--radius-sm);
  background:rgba(255,255,255,0.04);border:1px solid var(--border);
  text-align:left;font-size:0.9rem;font-weight:500;
  transition:all var(--trans);cursor:pointer;
}
.quiz-choice:hover:not(:disabled){background:rgba(124,107,255,0.12);border-color:var(--accent)}
.quiz-choice.correct{background:rgba(46,213,115,0.12);border-color:var(--success);color:var(--success)}
.quiz-choice.wrong{background:rgba(255,71,87,0.12);border-color:var(--danger);color:var(--danger)}
.quiz-choice:disabled{cursor:default}

/* Complete */
.complete-card{
  padding:40px 32px;text-align:center;position:relative;overflow:hidden;
  background:linear-gradient(135deg,rgba(124,107,255,0.1),rgba(255,107,157,0.07));
}
.complete-icon{font-size:4rem;margin-bottom:12px}
.complete-title{font-size:2rem;font-weight:800;margin-bottom:8px}
.complete-score{font-size:1.1rem;color:var(--text2);margin-bottom:16px}
.complete-stars{font-size:1.8rem;margin-bottom:24px;letter-spacing:4px}
.complete-actions{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}

/* SRS */
.srs-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}
.srs-card{padding:32px;text-align:center;cursor:pointer}
.srs-english{font-size:1.3rem;font-weight:700;margin-bottom:8px}
.srs-prompt{color:var(--text2);font-size:0.85rem;margin-bottom:16px}
.srs-rating-btns{display:flex;gap:10px;justify-content:center}
.srs-btn{font-size:0.85rem}
.srs-hard{border:1px solid rgba(255,71,87,0.4);color:var(--danger)}
.srs-ok{border:1px solid rgba(249,168,37,0.4);color:var(--accent4)}
.srs-easy{border:1px solid rgba(46,213,115,0.4);color:var(--success)}

/* ---------- Logs ---------- */
.logs-list{display:flex;flex-direction:column;gap:8px}
.log-entry{
  display:flex;align-items:flex-start;gap:12px;
  padding:14px 16px;border-radius:var(--radius-sm);
  background:var(--surface);border:1px solid var(--border);
  transition:all var(--trans);
}
.log-entry:hover{border-color:var(--border-strong)}
.log-entry.selected{border-color:var(--accent);background:rgba(124,107,255,0.08)}
.log-check{width:18px;height:18px;border-radius:4px;border:1px solid var(--border);
  appearance:none;-webkit-appearance:none;background:transparent;cursor:pointer;flex-shrink:0;margin-top:2px;}
.log-check:checked{background:var(--accent);border-color:var(--accent)}
.log-icon{font-size:1.3rem;flex-shrink:0}
.log-body{flex:1;min-width:0}
.log-type{font-size:0.75rem;font-weight:700;text-transform:uppercase;letter-spacing:0.06em;color:var(--accent);margin-bottom:2px}
.log-detail{font-size:0.9rem;color:var(--text)}
.log-time{font-size:0.75rem;color:var(--text3);margin-top:4px}
.empty-state{text-align:center;padding:60px 20px;color:var(--text2)}
.empty-icon{font-size:3rem;margin-bottom:12px}

/* ---------- Settings ---------- */
.settings-card{padding:24px;margin-bottom:16px}
.settings-section-title{font-size:1rem;font-weight:700;margin-bottom:6px}
.settings-desc{color:var(--text2);font-size:0.85rem;margin-bottom:16px}
.mode-selector{display:flex;gap:12px;flex-wrap:wrap}
.mode-option{flex:1;min-width:180px;cursor:pointer}
.mode-option input[type=radio]{display:none}
.mode-card{
  padding:16px;border-radius:var(--radius-sm);
  border:1px solid var(--border);
  display:flex;flex-direction:column;gap:4px;
  transition:all var(--trans);
}
.mode-option input:checked + .mode-card{border-color:var(--accent);background:rgba(124,107,255,0.1)}
.mode-card:hover{border-color:var(--border-strong)}
.mode-icon{font-size:1.5rem;margin-bottom:4px}
.mode-card strong{font-size:0.9rem}
.mode-card small{color:var(--text2);font-size:0.78rem}
.danger-zone{border-color:rgba(255,71,87,0.2)}
.danger-title{color:var(--danger)}
.danger-grid{display:flex;flex-direction:column;gap:20px}
.danger-item h4{font-size:0.9rem;font-weight:700;margin-bottom:4px}
.danger-item p{color:var(--text2);font-size:0.82rem;margin-bottom:10px}
.lang-reset-buttons{display:flex;gap:8px;flex-wrap:wrap}

/* ---------- Confirm Dialog ---------- */
.overlay{
  position:fixed;inset:0;z-index:200;
  background:rgba(0,0,0,0.6);backdrop-filter:blur(4px);
  display:flex;align-items:center;justify-content:center;padding:24px;
}
.confirm-dialog{padding:32px;max-width:380px;width:100%;text-align:center}
.confirm-icon{font-size:2.5rem;margin-bottom:12px}
.confirm-dialog h3{font-size:1.2rem;font-weight:700;margin-bottom:8px}
.confirm-dialog p{color:var(--text2);font-size:0.9rem;margin-bottom:24px}
.confirm-actions{display:flex;gap:12px;justify-content:center}

/* ---------- Toast ---------- */
.toast-container{
  position:fixed;bottom:90px;right:20px;
  display:flex;flex-direction:column;gap:8px;z-index:300;
}
.toast{
  padding:12px 18px;border-radius:var(--radius-sm);
  font-size:0.85rem;font-weight:600;
  background:var(--surface);border:1px solid var(--border);
  backdrop-filter:blur(16px);
  animation:toastIn 0.3s ease both;
  min-width:200px;max-width:320px;
}
.toast.success{border-color:var(--success);color:var(--success)}
.toast.error{border-color:var(--danger);color:var(--danger)}
.toast.info{border-color:var(--accent);color:var(--accent)}
@keyframes toastIn{from{opacity:0;transform:translateX(20px)}to{opacity:1;transform:translateX(0)}}

/* ---------- Confetti ---------- */
.complete-confetti{position:absolute;inset:0;pointer-events:none;overflow:hidden}
.confetti-piece{
  position:absolute;width:8px;height:8px;
  animation:confettiFall 1.5s ease-out forwards;
}
@keyframes confettiFall{
  from{transform:translateY(-10px) rotate(0deg);opacity:1}
  to{transform:translateY(300px) rotate(360deg);opacity:0}
}

/* ---------- Responsive ---------- */
@media(max-width:480px){
  .dashboard-hero{flex-direction:column}
  .hero-visual{display:none}
  .auth-card{padding:28px 20px}
  .flip-card{height:280px}
  .native-word{font-size:2rem}
}