/* ============================================================
   TENSES HUB — Redesigned with Cyan/Navy Palette
   ============================================================ */

/* ── PAGE HERO ── */
.tenses-hero {
  background: linear-gradient(135deg, rgba(0,119,182,0.14), rgba(0,180,216,0.08), rgba(124,58,237,0.07));
  border:1px solid rgba(0,229,255,0.15);
  border-radius:20px; padding:28px 32px; margin-bottom:24px;
  position:relative; overflow:hidden;
  display:flex; align-items:center; justify-content:space-between; gap:20px;
}
.tenses-hero::before {
  content:''; position:absolute; top:-60px; right:-60px;
  width:220px; height:220px; border-radius:50%;
  background:radial-gradient(circle, rgba(0,229,255,0.1), transparent 70%);
}
.tenses-hero-text h1 {
  font-size:1.8rem; font-weight:800;
  background:linear-gradient(135deg, #e8f4fd, #00e5ff, #7c3aed);
  -webkit-background-clip:text; -webkit-text-fill-color:transparent;
  background-clip:text; margin-bottom:6px;
}
.tenses-hero-text p { color:var(--text-secondary); font-size:0.9rem; line-height:1.5; }
.tenses-hero-stats { display:flex; gap:16px; flex-shrink:0; }
.hero-stat {
  text-align:center;
  background:rgba(0,229,255,0.05);
  border:1px solid rgba(0,229,255,0.12);
  border-radius:14px; padding:12px 18px;
  backdrop-filter:blur(10px);
}
.hero-stat-value { font-size:1.7rem; font-weight:800; color:var(--text-primary); line-height:1; }
.hero-stat-value.accent { color:var(--accent); text-shadow:0 0 16px rgba(0,229,255,0.4); }
.hero-stat-value.success { color:var(--success); }
.hero-stat-value.warning { color:var(--warning); }
.hero-stat-label { font-size:0.7rem; color:var(--text-secondary); text-transform:uppercase; letter-spacing:0.07em; font-weight:600; margin-top:4px; }

/* ── LAYOUT ── */
.tenses-layout { display:grid; grid-template-columns:280px 1fr; gap:20px; align-items:start; }

/* ── SIDEBAR ── */
.tenses-sidebar {
  background:rgba(13,21,38,0.7);
  border:1px solid rgba(0,229,255,0.1);
  border-radius:18px; padding:14px;
  height:calc(100vh - 160px);
  position:sticky; top:76px;
  overflow-y:auto; backdrop-filter:blur(20px);
}
.tenses-sidebar::-webkit-scrollbar { width:3px; }
.tenses-sidebar::-webkit-scrollbar-thumb { background:rgba(0,229,255,0.15); border-radius:4px; }
.sidebar-header { padding:6px 10px 14px; border-bottom:1px solid rgba(0,229,255,0.08); margin-bottom:10px; }
.sidebar-header-title { font-size:0.7rem; font-weight:700; color:var(--text-muted); text-transform:uppercase; letter-spacing:0.1em; }

.tree-group { margin-bottom:4px; }
.tree-group-title {
  display:flex; align-items:center; gap:8px;
  font-size:0.78rem; font-weight:700; color:var(--text-primary);
  padding:9px 10px; border-radius:10px; cursor:pointer;
  transition:var(--transition); user-select:none;
}
.tree-group-title:hover { background:rgba(0,229,255,0.06); }
.tree-group-icon {
  width:28px; height:28px; border-radius:8px;
  display:flex; align-items:center; justify-content:center;
  background:color-mix(in srgb, var(--group-color) 18%, transparent);
  color:var(--group-color); flex-shrink:0;
}
.tree-group-icon .material-icons { font-size:15px; }
.tree-chevron { margin-left:auto; color:var(--text-muted); font-size:16px !important; transition:transform 0.25s ease; }
.tree-group.open .tree-chevron { transform:rotate(90deg); }
.tree-items {
  margin:3px 0 3px 14px; border-left:1.5px solid rgba(0,229,255,0.1); padding-left:12px;
  display:flex; flex-direction:column; gap:1px;
  overflow:hidden; max-height:0; transition:max-height 0.35s cubic-bezier(0.4,0,0.2,1);
}
.tree-group.open .tree-items { max-height:600px; }
.tree-lesson {
  display:flex; align-items:center; gap:7px;
  padding:8px 10px; border-radius:9px;
  font-size:0.78rem; font-weight:500; color:var(--text-secondary);
  cursor:pointer; transition:var(--transition);
}
.tree-lesson:hover { color:var(--text-primary); background:rgba(0,229,255,0.04); }
.tree-lesson.active {
  color:var(--group-color);
  background:color-mix(in srgb,var(--group-color) 12%,transparent); font-weight:600;
}
.tree-lesson-dot { width:5px; height:5px; border-radius:50%; background:var(--border); flex-shrink:0; transition:var(--transition); }
.tree-lesson.active .tree-lesson-dot { background:var(--group-color); box-shadow:0 0 6px var(--group-color); }
.tree-lesson-done { margin-left:auto; color:var(--success); font-size:15px !important; opacity:0; transition:var(--transition); }
.tree-lesson.done .tree-lesson-done { opacity:1; }

/* ── CONTENT AREA ── */
.tenses-content { min-height:70vh; }

/* ── BREADCRUMB ── */
.tenses-breadcrumb { display:flex; align-items:center; gap:5px; font-size:0.76rem; color:var(--text-muted); margin-bottom:10px; }
.tenses-breadcrumb span { color:var(--text-secondary); }

/* ── CONTENT HEADER ── */
.tenses-content-header {
  background:rgba(13,21,38,0.7);
  border:1px solid rgba(0,229,255,0.1);
  border-radius:16px; padding:20px 24px; margin-bottom:16px;
  display:flex; align-items:center; gap:16px;
}
.content-header-icon {
  width:48px; height:48px; border-radius:13px;
  display:flex; align-items:center; justify-content:center;
  background:color-mix(in srgb,var(--group-color,var(--accent)) 18%,transparent);
  color:var(--group-color,var(--accent)); flex-shrink:0;
}
.content-header-icon .material-icons { font-size:24px; }
.tenses-title { font-size:1.25rem; font-weight:800; color:var(--text-primary); margin-bottom:3px; line-height:1.3; }
.tenses-subtitle { font-size:0.8rem; color:var(--text-muted); }

/* ── TABS ── */
.tenses-tabs {
  display:flex; gap:5px;
  background:rgba(13,21,38,0.7); padding:4px;
  border-radius:12px; border:1px solid rgba(0,229,255,0.08); margin-bottom:18px;
}
.tenses-tab {
  flex:1; display:flex; align-items:center; justify-content:center; gap:6px;
  padding:10px 16px; border-radius:9px; font-size:0.85rem; font-weight:600;
  color:var(--text-secondary); cursor:pointer; transition:var(--transition);
}
.tenses-tab:hover { color:var(--text-primary); background:rgba(0,229,255,0.05); }
.tenses-tab .material-icons { font-size:16px; }
.tenses-tab.active {
  background:linear-gradient(135deg, #0077b6, var(--accent-3));
  color:#fff; box-shadow:0 4px 14px rgba(0,119,182,0.4);
}

/* ── THEORY VIEW ── */
.theory-view { display:none; }
.theory-view.active { display:block; animation:fadeSlideUp 0.3s ease; }

.theory-section {
  background:rgba(13,21,38,0.7); border:1px solid rgba(0,229,255,0.08);
  border-radius:14px; padding:20px 24px; margin-bottom:14px;
  position:relative; overflow:hidden; transition:var(--transition);
}
.theory-section:hover { border-color:rgba(0,229,255,0.18); }
.theory-section::before {
  content:''; position:absolute; top:0; left:0; width:3px; height:100%;
  background:var(--section-color,var(--accent)); border-radius:4px 0 0 4px;
  box-shadow:0 0 10px var(--section-color,var(--accent));
}
.theory-section-title {
  display:flex; align-items:center; gap:8px;
  font-size:0.92rem; font-weight:700; color:var(--text-primary); margin-bottom:14px;
}
.theory-section-badge {
  font-size:0.66rem; font-weight:700; text-transform:uppercase; letter-spacing:0.06em;
  padding:2px 8px; border-radius:20px;
  background:color-mix(in srgb,var(--section-color,var(--accent)) 15%,transparent);
  color:var(--section-color,var(--accent));
  border:1px solid color-mix(in srgb,var(--section-color,var(--accent)) 30%,transparent);
  margin-left:auto;
}
.theory-concept-text { font-size:0.92rem; line-height:1.8; color:var(--text-secondary); }

/* Formula */
.formula-grid { display:flex; flex-direction:column; gap:8px; }
.formula-card {
  background:rgba(0,0,0,0.3); border:1px solid rgba(255,255,255,0.06);
  border-radius:10px; padding:12px 16px;
  display:flex; align-items:center; gap:12px;
}
.formula-type-chip {
  font-size:0.66rem; font-weight:700; text-transform:uppercase; letter-spacing:0.06em;
  padding:3px 9px; border-radius:20px; flex-shrink:0; min-width:80px; text-align:center;
}
.formula-type-chip.pos { background:rgba(0,214,143,0.12); color:var(--success); border:1px solid rgba(0,214,143,0.25); }
.formula-type-chip.neg { background:rgba(255,77,109,0.12); color:var(--danger); border:1px solid rgba(255,77,109,0.25); }
.formula-type-chip.que { background:rgba(255,183,3,0.12);  color:var(--warning); border:1px solid rgba(255,183,3,0.25); }
.formula-type-chip.wh  { background:rgba(0,229,255,0.1);   color:var(--accent);  border:1px solid rgba(0,229,255,0.25); }
.formula-type-chip.default { background:rgba(124,58,237,0.12); color:var(--accent-3); border:1px solid rgba(124,58,237,0.25); }
.formula-content { font-family:'Courier New',monospace; font-size:0.9rem; color:var(--text-primary); font-weight:600; flex:1; }

/* Formula symbol notes */
.formula-notes { margin-top:12px; overflow:hidden; border:1px solid rgba(0,229,255,.12); border-radius:11px; background:rgba(0,229,255,.025); }
.formula-notes>summary { display:grid; grid-template-columns:auto 1fr auto; align-items:center; gap:10px; min-height:58px; padding:11px 14px; list-style:none; cursor:pointer; }
.formula-notes>summary::-webkit-details-marker { display:none; }
.formula-notes>summary>.material-icons:first-child { display:grid; place-items:center; width:34px; height:34px; border-radius:9px; color:var(--accent); background:rgba(0,229,255,.09); font-size:18px; }
.formula-notes>summary span:nth-child(2) b,.formula-notes>summary span:nth-child(2) small { display:block; }
.formula-notes>summary span:nth-child(2) b { color:var(--text-primary); font-size:.82rem; }
.formula-notes>summary span:nth-child(2) small { margin-top:2px; color:var(--text-muted); font-size:.66rem; }
.formula-notes-chevron { color:var(--accent); font-size:19px; transition:transform .2s ease; }
.formula-notes[open] .formula-notes-chevron { transform:rotate(180deg); }
.formula-note-grid { display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); gap:8px; padding:12px; border-top:1px solid rgba(0,229,255,.1); }
.formula-note-item { display:grid; grid-template-columns:minmax(62px,auto) 1fr; align-items:start; gap:11px; padding:12px; border:1px solid rgba(255,255,255,.065); border-radius:9px; background:rgba(0,0,0,.16); }
.formula-note-item>code { display:grid; place-items:center; min-height:30px; padding:5px 8px; border-radius:7px; color:var(--accent); background:rgba(0,229,255,.09); font-family:'Courier New',monospace; font-size:.72rem; font-weight:800; text-align:center; }
.formula-note-item b { display:block; color:var(--text-primary); font-size:.76rem; }
.formula-note-item p { margin-top:4px; color:var(--text-secondary); font-size:.7rem; line-height:1.5; }
.formula-note-item small { display:block; margin-top:7px; color:var(--text-muted); font-size:.65rem; line-height:1.45; }
.formula-note-item small span { color:var(--success); font-weight:750; }

/* Usage & Signs */
.usage-list, .signs-list { list-style:none; display:flex; flex-direction:column; gap:7px; }
.usage-list li, .signs-list li {
  display:flex; align-items:flex-start; gap:10px;
  font-size:0.88rem; line-height:1.65; color:var(--text-secondary);
  padding:9px 12px; border-radius:9px;
  background:rgba(0,229,255,0.03); border:1px solid rgba(0,229,255,0.06);
}
.usage-list li .li-icon, .signs-list li .li-icon { font-size:16px !important; flex-shrink:0; margin-top:2px; }
.usage-list li .li-icon { color:var(--success); }
.signs-list li .li-icon { color:var(--warning); }

/* ── QUIZ VIEW ── */
.quiz-view { display:none; }
.quiz-view.active { display:block; animation:fadeSlideUp 0.3s ease; }
.quiz-wrapper {
  background:rgba(13,21,38,0.7); border:1px solid rgba(0,229,255,0.1);
  border-radius:18px; padding:28px; position:relative; overflow:hidden;
}
.quiz-wrapper::before {
  content:''; position:absolute; top:0; left:0; right:0; height:2px;
  background:linear-gradient(90deg,var(--accent),var(--accent-3),var(--success));
}

.tq-progress-bar-wrap { height:4px; background:rgba(255,255,255,0.07); border-radius:10px; margin-bottom:20px; overflow:hidden; }
.tq-progress-bar { height:100%; background:linear-gradient(90deg,var(--accent),var(--accent-3)); border-radius:10px; transition:width 0.5s ease; }
.tq-meta { display:flex; align-items:center; justify-content:space-between; margin-bottom:20px; }
.tq-counter { font-size:0.78rem; font-weight:600; color:var(--text-muted); }
.tq-counter b { color:var(--text-primary); font-size:0.95rem; }
.tq-score-badge {
  display:flex; align-items:center; gap:5px;
  background:rgba(0,214,143,0.1); border:1px solid rgba(0,214,143,0.25);
  border-radius:20px; padding:4px 12px; font-size:0.78rem; font-weight:700; color:var(--success);
}
.tq-question {
  font-size:1.3rem; font-weight:700; color:var(--text-primary);
  text-align:center; margin-bottom:24px; line-height:1.5;
  padding:18px; background:rgba(0,229,255,0.05);
  border-radius:13px; border:1px solid rgba(0,229,255,0.12);
}
.tq-formula-hint { margin:-14px 0 18px; overflow:hidden; border:1px solid rgba(255,183,3,.18); border-radius:11px; background:rgba(255,183,3,.035); }
.tq-formula-hint>summary { display:grid; grid-template-columns:auto 1fr auto; align-items:center; gap:9px; min-height:54px; padding:10px 13px; list-style:none; cursor:pointer; }
.tq-formula-hint>summary::-webkit-details-marker { display:none; }
.tq-formula-hint>summary>.material-icons:first-child { display:grid; place-items:center; width:32px; height:32px; border-radius:8px; color:var(--warning); background:rgba(255,183,3,.1); font-size:17px; }
.tq-formula-hint>summary span:nth-child(2) b,.tq-formula-hint>summary span:nth-child(2) small { display:block; }
.tq-formula-hint>summary span:nth-child(2) b { color:var(--text-primary); font-size:.78rem; }
.tq-formula-hint>summary span:nth-child(2) small { margin-top:2px; color:var(--text-muted); font-size:.63rem; }
.tq-formula-hint-chevron { color:var(--warning); font-size:18px; transition:transform .2s ease; }
.tq-formula-hint[open] .tq-formula-hint-chevron { transform:rotate(180deg); }
.tq-formula-hint>div { display:grid; grid-template-columns:auto 1fr; align-items:center; gap:8px 12px; padding:12px 13px; border-top:1px solid rgba(255,183,3,.15); }
.tq-formula-hint>div>span { padding:4px 8px; border-radius:99px; color:var(--warning); background:rgba(255,183,3,.09); font-size:.61rem; font-weight:800; }
.tq-formula-hint code { color:var(--text-primary); font-family:'Courier New',monospace; font-size:.82rem; font-weight:700; line-height:1.5; }
.tq-formula-hint p { grid-column:1/3; color:var(--text-secondary); font-size:.68rem; line-height:1.5; }
.tq-options { display:grid; grid-template-columns:1fr 1fr; gap:10px; margin-bottom:18px; }
.tq-option {
  padding:13px 16px; border-radius:11px;
  background:rgba(255,255,255,0.04); border:2px solid rgba(255,255,255,0.07);
  color:var(--text-primary); font-size:0.9rem; font-weight:600;
  cursor:pointer; transition:all 0.2s ease; text-align:left;
  display:flex; align-items:center; gap:9px;
}
.tq-option-letter {
  width:26px; height:26px; border-radius:7px;
  background:rgba(255,255,255,0.07);
  display:flex; align-items:center; justify-content:center;
  font-size:0.72rem; font-weight:800; flex-shrink:0;
  color:var(--text-muted); transition:var(--transition);
}
.tq-option:hover:not(:disabled) {
  border-color:var(--accent); background:rgba(0,229,255,0.08);
  transform:translateY(-2px); box-shadow:0 5px 16px rgba(0,229,255,0.15);
}
.tq-option:hover:not(:disabled) .tq-option-letter { background:var(--accent); color:#070c14; }
.tq-option.correct { border-color:var(--success); background:rgba(0,214,143,0.1); color:var(--success); }
.tq-option.correct .tq-option-letter { background:var(--success); color:#070c14; }
.tq-option.wrong { border-color:var(--danger); background:rgba(255,77,109,0.1); color:var(--danger); }
.tq-option.wrong .tq-option-letter { background:var(--danger); color:#fff; }
.tq-option:disabled { cursor:not-allowed; transform:none !important; box-shadow:none !important; }

.tq-feedback { padding:14px 18px; border-radius:11px; display:none; animation:fadeSlideUp 0.25s ease; margin-top:4px; }
.tq-feedback.show { display:block; }
.tq-feedback.success { background:rgba(0,214,143,0.09); border:1px solid rgba(0,214,143,0.25); }
.tq-feedback.error   { background:rgba(255,77,109,0.08); border:1px solid rgba(255,77,109,0.25); }
.tq-feedback-title { display:flex; align-items:center; gap:7px; font-weight:700; font-size:0.92rem; margin-bottom:5px; }
.tq-feedback.success .tq-feedback-title { color:var(--success); }
.tq-feedback.error   .tq-feedback-title { color:var(--danger); }
.tq-feedback-text { font-size:0.86rem; line-height:1.6; color:var(--text-secondary); }
.tq-actions { display:flex; align-items:center; justify-content:flex-end; margin-top:18px; gap:9px; }
#tq-next-btn { display:none; }

/* ── RESULT SCREEN ── */
.tq-result { display:none; text-align:center; padding:20px; animation:fadeSlideUp 0.4s ease; }
.tq-result.show { display:block; }
.tq-result-emoji { font-size:3.5rem; margin-bottom:12px; }
.tq-result h2 { font-size:1.5rem; font-weight:800; margin-bottom:6px; }
.tq-result-sub { color:var(--text-secondary); font-size:0.88rem; margin-bottom:24px; }
.tq-result-scorecard {
  display:inline-flex; align-items:center; justify-content:center; gap:28px;
  background:rgba(0,229,255,0.04); border:1px solid rgba(0,229,255,0.12);
  border-radius:18px; padding:24px 36px; margin-bottom:24px;
}
.tq-score-item { text-align:center; }
.tq-score-item .score-num { font-size:2rem; font-weight:800; line-height:1; margin-bottom:4px; }
.tq-score-item .score-label { font-size:0.7rem; color:var(--text-muted); text-transform:uppercase; letter-spacing:0.07em; font-weight:600; }
.tq-score-divider { width:1px; height:50px; background:rgba(0,229,255,0.15); }
.tq-result-actions { display:flex; justify-content:center; gap:10px; }

/* ── WELCOME STATE ── */
.tenses-welcome { display:flex; flex-direction:column; align-items:center; justify-content:center; padding:80px 20px; text-align:center; color:var(--text-muted); }
.tenses-welcome-icon { font-size:4rem; margin-bottom:20px; opacity:0.5; }
.tenses-welcome h3 { font-size:1.15rem; font-weight:700; color:var(--text-secondary); margin-bottom:8px; }
.tenses-welcome p { font-size:0.85rem; }

/* ── ANIMATIONS ── */
@keyframes fadeSlideUp { from{opacity:0;transform:translateY(12px);} to{opacity:1;transform:translateY(0);} }

/* ── RESPONSIVE ── */
@media (max-width:992px) {
  .tenses-layout { grid-template-columns:1fr; }
  .tenses-sidebar { height:auto; position:static; max-height:360px; }
  .tenses-hero { flex-direction:column; align-items:flex-start; }
  .tenses-hero-stats { gap:10px; flex-wrap:wrap; }
  .tq-options { grid-template-columns:1fr; }
  .tenses-content-header { flex-direction:column; align-items:flex-start; }
}
@media (max-width:600px) {
  .tenses-hero { padding:20px; }
  .quiz-wrapper { padding:18px; }
  .tq-question { font-size:1.05rem; }
  .tq-result-scorecard { gap:18px; padding:18px 22px; flex-wrap:wrap; }
  .formula-note-grid { grid-template-columns:1fr; }
  .formula-note-item { grid-template-columns:55px 1fr; }
}