/* ================================================================
   TechEnglish – English Learning Website for Brazilian Devs
   Dark tech theme with indigo/purple accents
================================================================ */

:root {
  --bg-primary: #0d0d1a;
  --bg-secondary: #13132b;
  --bg-card: #1a1a35;
  --bg-card-hover: #222248;
  --bg-sidebar: #10102a;
  --border: #2a2a55;
  --border-light: #3a3a70;
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --secondary: #8b5cf6;
  --accent: #06b6d4;
  --accent2: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --gold: #fbbf24;
  --text-primary: #f0f0ff;
  --text-secondary: #a0a0cc;
  --text-muted: #606090;
  --gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --gradient-accent: linear-gradient(135deg, #06b6d4 0%, #6366f1 100%);
  --gradient-gold: linear-gradient(135deg, #f59e0b 0%, #fbbf24 100%);
  --shadow: 0 4px 24px rgba(99, 102, 241, 0.18);
  --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.5);
  --radius: 14px;
  --radius-sm: 8px;
  --transition: all 0.28s cubic-bezier(0.4, 0, 0.2, 1);
  --sidebar-width: 260px;
  --header-height: 64px;
}

/* ── RESET ────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; }
button { cursor: pointer; font-family: inherit; border: none; outline: none; }
input, select { font-family: inherit; border: none; outline: none; }
ul, ol { list-style: none; }

/* ── SCROLLBAR ────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb { background: var(--border-light); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--primary); }

/* ── LAYOUT ───────────────────────────────────────────────────── */
#app { display: flex; height: 100vh; }

/* ── SIDEBAR ──────────────────────────────────────────────────── */
#sidebar {
  width: var(--sidebar-width);
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0; left: 0; bottom: 0;
  z-index: 100;
  transition: var(--transition);
  overflow-y: auto;
}

.sidebar-logo {
  padding: 24px 20px 20px;
  border-bottom: 1px solid var(--border);
}

.logo-title {
  font-size: 1.3rem;
  font-weight: 800;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.5px;
}

.logo-sub {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 2px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.sidebar-nav {
  padding: 12px 10px;
  flex: 1;
}

.nav-section-title {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  padding: 10px 10px 4px;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  margin-bottom: 2px;
}

.nav-item:hover {
  background: rgba(99, 102, 241, 0.12);
  color: var(--text-primary);
}

.nav-item.active {
  background: rgba(99, 102, 241, 0.2);
  color: #a5b4fc;
  font-weight: 600;
}

.nav-icon { font-size: 1.1rem; width: 22px; text-align: center; }

.sidebar-footer {
  padding: 16px;
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-muted);
  text-align: center;
}

/* ── MAIN CONTENT ─────────────────────────────────────────────── */
#main {
  margin-left: var(--sidebar-width);
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  overflow-y: auto;
  overflow-x: hidden;
}

.section-wrapper {
  display: none;
  flex-direction: column;
  min-height: 100%;
  animation: fadeIn 0.3s ease;
}
.section-wrapper.active { display: flex; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── PAGE HEADER ──────────────────────────────────────────────── */
.page-header {
  padding: 36px 40px 28px;
  border-bottom: 1px solid var(--border);
}

.page-header h1 {
  font-size: 1.9rem;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.page-header p {
  color: var(--text-secondary);
  margin-top: 6px;
  font-size: 0.95rem;
}

.gradient-text {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.page-content { padding: 32px 40px; flex: 1; }

/* ── HOME ─────────────────────────────────────────────────────── */
.hero {
  background: linear-gradient(135deg, #1a1a3e 0%, #13132b 60%, #0d0d1a 100%);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 48px;
  margin-bottom: 32px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -60px; right: -60px;
  width: 250px; height: 250px;
  background: radial-gradient(circle, rgba(99,102,241,0.25) 0%, transparent 70%);
  pointer-events: none;
}

.hero h2 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 12px;
  line-height: 1.3;
}

.hero p {
  color: var(--text-secondary);
  max-width: 560px;
  font-size: 1rem;
  margin-bottom: 28px;
}

.hero-goal {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 0.88rem;
  color: #a5b4fc;
  margin-bottom: 8px;
  max-width: 520px;
}

.wod-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 32px;
  position: relative;
  overflow: hidden;
}

.wod-card::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 4px;
  background: var(--gradient);
  border-radius: 4px 0 0 4px;
}

.wod-label {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: #a5b4fc;
  margin-bottom: 12px;
}

.wod-word {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.wod-phonetics {
  font-size: 0.9rem;
  color: var(--accent);
  font-style: italic;
  margin-bottom: 10px;
}

.wod-definition {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 16px;
}

.wod-example {
  background: rgba(99, 102, 241, 0.08);
  border-left: 3px solid var(--primary);
  padding: 10px 14px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-style: italic;
}

.section-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
  margin-bottom: 32px;
}

.section-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.section-card:hover {
  border-color: var(--primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}

.section-card::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 3px;
  background: var(--gradient);
  transform: scaleX(0);
  transition: var(--transition);
  border-radius: 0 0 var(--radius) var(--radius);
}

.section-card:hover::after { transform: scaleX(1); }

.section-card-icon { font-size: 2rem; margin-bottom: 12px; }
.section-card-title { font-size: 1.05rem; font-weight: 700; margin-bottom: 6px; }
.section-card-desc { font-size: 0.82rem; color: var(--text-muted); line-height: 1.5; }

.tip-box {
  background: rgba(6, 182, 212, 0.08);
  border: 1px solid rgba(6, 182, 212, 0.25);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 16px;
}

.tip-box-title {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--accent);
  margin-bottom: 8px;
}

.tip-box p { font-size: 0.9rem; color: var(--text-secondary); }

/* ── VOCABULARY ───────────────────────────────────────────────── */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
  align-items: center;
}

.filter-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 7px 16px;
  border-radius: 50px;
  font-size: 0.82rem;
  font-weight: 500;
  transition: var(--transition);
}

.filter-btn:hover {
  border-color: var(--primary);
  color: var(--text-primary);
}

.filter-btn.active {
  background: rgba(99, 102, 241, 0.2);
  border-color: var(--primary);
  color: #a5b4fc;
  font-weight: 700;
}

.search-input {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: 8px 16px;
  border-radius: 50px;
  font-size: 0.88rem;
  width: 220px;
  transition: var(--transition);
}

.search-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

.search-input::placeholder { color: var(--text-muted); }

/* Vocabulary card grid */
.vocab-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
}

.vocab-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0;
  perspective: 1000px;
  height: 280px;
  cursor: pointer;
}

.vocab-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.55s cubic-bezier(0.4, 0, 0.2, 1);
}

.vocab-card.flipped .vocab-card-inner { transform: rotateY(180deg); }

.vocab-card-front,
.vocab-card-back {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--radius);
  padding: 24px;
  display: flex;
  flex-direction: column;
}

.vocab-card-front {
  background: var(--bg-card);
  border: 1px solid var(--border);
  justify-content: space-between;
  overflow: hidden;
}

.vocab-card-back {
  background: linear-gradient(135deg, #1e1e45 0%, #252555 100%);
  border: 1px solid var(--primary);
  transform: rotateY(180deg);
  justify-content: flex-start;
  gap: 10px;
  overflow: auto;
}

.vocab-word {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-primary);
}

.vocab-phonetics {
  font-size: 0.85rem;
  color: var(--accent);
  margin-top: 2px;
  font-style: italic;
}

.vocab-pos {
  display: inline-block;
  background: rgba(99, 102, 241, 0.15);
  color: #a5b4fc;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 3px 8px;
  border-radius: 50px;
  margin-top: 8px;
}

.vocab-definition {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.45;
  margin-top: 8px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.vocab-category-badge {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 3px 8px;
  border-radius: 50px;
  align-self: flex-start;
}

.cat-ai { background: rgba(139, 92, 246, 0.2); color: #c4b5fd; }
.cat-data { background: rgba(6, 182, 212, 0.2); color: #67e8f9; }
.cat-dev { background: rgba(16, 185, 129, 0.2); color: #6ee7b7; }
.cat-business { background: rgba(245, 158, 11, 0.2); color: #fde68a; }
.cat-travel { background: rgba(239, 68, 68, 0.2); color: #fca5a5; }
.cat-everyday { background: rgba(99, 102, 241, 0.2); color: #a5b4fc; }

.vocab-back-label {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-muted);
}

.vocab-back-example {
  font-size: 0.85rem;
  font-style: italic;
  color: var(--text-secondary);
  background: rgba(0,0,0,0.2);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--primary);
}

.vocab-back-context {
  font-size: 0.82rem;
  color: var(--accent);
}

.card-flip-hint {
  font-size: 0.68rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ── STORIES ──────────────────────────────────────────────────── */
.story-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  margin-bottom: 32px;
}

.story-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  cursor: pointer;
  transition: var(--transition);
}

.story-card:hover {
  border-color: var(--secondary);
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(139, 92, 246, 0.2);
}

.story-level {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 3px 10px;
  border-radius: 50px;
  display: inline-block;
  margin-bottom: 12px;
}

.level-beginner { background: rgba(16, 185, 129, 0.15); color: #6ee7b7; }
.level-intermediate { background: rgba(245, 158, 11, 0.15); color: #fde68a; }
.level-advanced { background: rgba(239, 68, 68, 0.15); color: #fca5a5; }

.story-card-title { font-size: 1.1rem; font-weight: 700; margin-bottom: 8px; }
.story-card-desc { font-size: 0.83rem; color: var(--text-muted); line-height: 1.5; margin-bottom: 16px; }

.story-meta {
  display: flex;
  gap: 12px;
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Story reader */
.story-reader { display: none; }
.story-reader.active { display: block; }
.story-list-view { display: block; }
.story-list-view.hidden { display: none; }

.story-reader-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 28px;
}

.back-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  transition: var(--transition);
}

.back-btn:hover { border-color: var(--primary); color: var(--text-primary); }

.story-body {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  max-width: 760px;
  font-size: 1.05rem;
  line-height: 1.9;
  color: var(--text-secondary);
}

.story-body h3 {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.story-body p { margin-bottom: 18px; }

.vocab-highlight {
  color: #a5b4fc;
  border-bottom: 1px dotted #a5b4fc;
  cursor: pointer;
  position: relative;
  font-weight: 600;
}

.vocab-highlight:hover { color: #c7d2fe; }

.vocab-tooltip {
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  background: #1e1e55;
  border: 1px solid var(--primary);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 0.82rem;
  color: var(--text-primary);
  white-space: nowrap;
  z-index: 1000;
  box-shadow: 0 8px 24px rgba(0,0,0,0.5);
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.2s;
}

.vocab-highlight:hover .vocab-tooltip { opacity: 1; }

.story-vocab-list {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 32px;
  max-width: 760px;
  margin-top: 24px;
}

.story-vocab-list h4 {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.story-vocab-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}

.story-vocab-item:last-child { border-bottom: none; }

.story-vocab-word { font-weight: 700; color: #a5b4fc; min-width: 140px; font-size: 0.95rem; }
.story-vocab-def { font-size: 0.85rem; color: var(--text-secondary); }

/* ── GRAMMAR ──────────────────────────────────────────────────── */
.grammar-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 28px;
}

.grammar-tab {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 8px 18px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  transition: var(--transition);
}

.grammar-tab:hover { border-color: var(--primary); color: var(--text-primary); }
.grammar-tab.active { background: rgba(99,102,241,0.18); border-color: var(--primary); color: #a5b4fc; font-weight: 700; }

.grammar-section { display: none; }
.grammar-section.active { display: block; }

.grammar-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 32px;
  margin-bottom: 20px;
}

.grammar-title {
  font-size: 1.2rem;
  font-weight: 800;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.grammar-subtitle {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 18px;
}

.grammar-explanation {
  color: var(--text-secondary);
  font-size: 0.93rem;
  line-height: 1.7;
  margin-bottom: 18px;
}

.grammar-formula {
  background: rgba(99, 102, 241, 0.1);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: var(--radius-sm);
  padding: 12px 18px;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  color: #c7d2fe;
  margin-bottom: 18px;
}

.examples-list { list-style: none; }

.examples-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.9rem;
}

.examples-list li:last-child { border-bottom: none; }

.en-sentence {
  color: var(--text-primary);
  font-style: italic;
  margin-bottom: 3px;
}

.pt-translation {
  color: var(--text-muted);
  font-size: 0.82rem;
}

.grammar-note {
  background: rgba(245, 158, 11, 0.1);
  border: 1px solid rgba(245, 158, 11, 0.3);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 0.85rem;
  color: #fde68a;
  margin-top: 14px;
  display: flex;
  gap: 8px;
  align-items: flex-start;
}

.grammar-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  margin-top: 10px;
}

.grammar-table th {
  background: rgba(99, 102, 241, 0.15);
  color: #a5b4fc;
  padding: 10px 14px;
  text-align: left;
  font-weight: 700;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.grammar-table td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
  vertical-align: top;
}

.grammar-table tr:last-child td { border-bottom: none; }
.grammar-table tr:hover td { background: rgba(99,102,241,0.05); }
.grammar-table td.en { color: var(--text-primary); font-style: italic; }

/* ── SLANG ────────────────────────────────────────────────────── */
.slang-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 14px;
}

.slang-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  transition: var(--transition);
}

.slang-card:hover {
  border-color: var(--secondary);
  background: var(--bg-card-hover);
}

.slang-expression {
  font-size: 1.05rem;
  font-weight: 800;
  color: #c4b5fd;
  margin-bottom: 4px;
}

.slang-meaning {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.slang-context {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 10px;
  background: rgba(139, 92, 246, 0.08);
  border-radius: var(--radius-sm);
  padding: 5px 10px;
}

.slang-formal {
  font-size: 0.78rem;
  color: var(--accent2);
  margin-bottom: 10px;
}

.slang-example {
  font-size: 0.84rem;
  font-style: italic;
  color: var(--text-muted);
  border-left: 3px solid var(--secondary);
  padding-left: 10px;
}

.slang-category-chip {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 2px 8px;
  border-radius: 50px;
  display: inline-block;
  margin-bottom: 10px;
}

.slang-office { background: rgba(16,185,129,0.15); color: #6ee7b7; }
.slang-everyday { background: rgba(99,102,241,0.15); color: #a5b4fc; }
.slang-idiom { background: rgba(245,158,11,0.15); color: #fde68a; }
.slang-email { background: rgba(6,182,212,0.15); color: #67e8f9; }

/* ── BUSINESS ENGLISH ─────────────────────────────────────────── */
.business-sections {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.business-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.business-block-header {
  background: rgba(99, 102, 241, 0.1);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.business-block-icon { font-size: 1.3rem; }
.business-block-title { font-size: 1rem; font-weight: 700; }

.business-phrases {
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.phrase-row {
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}

.phrase-row:last-child { border-bottom: none; }

.phrase-en {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 3px;
}

.phrase-pt {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 5px;
}

.phrase-context {
  font-size: 0.78rem;
  color: var(--accent2);
  background: rgba(16,185,129,0.08);
  border-radius: 4px;
  padding: 2px 8px;
  display: inline-block;
}

/* ── TECH TALK ────────────────────────────────────────────────── */
.tech-topic-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 28px;
}

.tech-topic-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 8px 16px;
  border-radius: 50px;
  font-size: 0.82rem;
  transition: var(--transition);
}

.tech-topic-btn:hover { border-color: var(--accent); color: var(--text-primary); }
.tech-topic-btn.active { background: rgba(6,182,212,0.15); border-color: var(--accent); color: #67e8f9; font-weight: 700; }

.tech-section { display: none; }
.tech-section.active { display: block; }

.tech-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 20px;
}

.tech-block h3 { font-size: 1.15rem; font-weight: 800; margin-bottom: 8px; }
.tech-block p { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 14px; line-height: 1.7; }

.tech-terms {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.tech-term-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  transition: var(--transition);
}

.tech-term-card:hover { border-color: var(--accent); }

.tech-term { font-weight: 700; font-size: 0.95rem; color: #67e8f9; margin-bottom: 4px; }
.tech-term-def { font-size: 0.82rem; color: var(--text-secondary); margin-bottom: 6px; line-height: 1.5; }
.tech-term-example { font-size: 0.78rem; font-style: italic; color: var(--text-muted); }

/* ── TRAVEL ───────────────────────────────────────────────────── */
.travel-scenarios {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.travel-scenario {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.travel-scenario-header {
  padding: 18px 24px;
  background: rgba(239, 68, 68, 0.08);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 12px;
}

.travel-scenario-icon { font-size: 1.5rem; }
.travel-scenario-title { font-size: 1rem; font-weight: 700; }

.travel-phrases {
  padding: 20px 24px;
}

.dialog-row {
  display: flex;
  gap: 16px;
  margin-bottom: 14px;
  font-size: 0.9rem;
}

.dialog-speaker {
  font-weight: 700;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  min-width: 60px;
  margin-top: 2px;
}

.you-speaker { color: var(--accent); }
.them-speaker { color: var(--text-muted); }

.dialog-text-en { color: var(--text-primary); margin-bottom: 2px; }
.dialog-text-pt { color: var(--text-muted); font-size: 0.8rem; }

.culture-tip {
  background: rgba(251, 191, 36, 0.08);
  border: 1px solid rgba(251, 191, 36, 0.25);
  border-radius: var(--radius-sm);
  padding: 14px 18px;
  margin-top: 12px;
  font-size: 0.85rem;
  color: var(--gold);
  display: flex;
  gap: 10px;
}

/* ── UTIL COMPONENTS ──────────────────────────────────────────── */
.badge {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 3px 10px;
  border-radius: 50px;
}

.badge-primary { background: rgba(99,102,241,0.18); color: #a5b4fc; }
.badge-accent { background: rgba(6,182,212,0.18); color: #67e8f9; }
.badge-success { background: rgba(16,185,129,0.18); color: #6ee7b7; }
.badge-warning { background: rgba(245,158,11,0.18); color: #fde68a; }
.badge-danger { background: rgba(239,68,68,0.18); color: #fca5a5; }

.divider {
  height: 1px;
  background: var(--border);
  margin: 24px 0;
}

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }

/* ── MOBILE TOGGLE ────────────────────────────────────────────── */
.sidebar-toggle {
  display: none;
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: var(--gradient);
  border: none;
  border-radius: 50%;
  width: 52px;
  height: 52px;
  font-size: 1.3rem;
  color: white;
  z-index: 200;
  box-shadow: 0 4px 16px rgba(99,102,241,0.4);
}

/* ── RESPONSIVE ───────────────────────────────────────────────── */
@media (max-width: 900px) {
  :root { --sidebar-width: 0px; }

  #sidebar {
    transform: translateX(-260px);
    width: 260px;
  }

  #sidebar.open {
    transform: translateX(0);
    box-shadow: 4px 0 32px rgba(0,0,0,0.6);
  }

  #main { margin-left: 0; }

  .sidebar-toggle { display: flex; align-items: center; justify-content: center; }

  .page-header, .page-content { padding-left: 20px; padding-right: 20px; }
  .hero { padding: 28px 24px; }
  .story-body { padding: 24px; }
  .vocab-grid { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  .page-header h1 { font-size: 1.4rem; }
  .grammar-block { padding: 20px; }
  .business-phrases { padding: 16px; }
}