/* ========================================
   Teach Page Styles
   ======================================== */

/* --- Page Header --- */
.page-header {
  position: relative;
  z-index: 1;
  padding: 120px 2rem 40px;
  text-align: center;
}

.page-header-inner {
  max-width: 700px;
  margin: 0 auto;
}

.page-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 900;
  letter-spacing: 3px;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1rem;
}

.page-desc {
  color: var(--text-secondary);
  font-size: 1.05rem;
}

/* --- Category Tabs --- */
.teach-nav {
  position: sticky;
  top: 72px;
  z-index: 100;
  background: rgba(5,5,16,0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-glass);
  padding: 0 2rem;
}

.teach-nav-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  gap: 0;
  overflow-x: auto;
  scrollbar-width: none;
}

.teach-nav-inner::-webkit-scrollbar { display: none; }

.teach-tab {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px 20px;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-secondary);
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.3s ease;
}

.teach-tab:hover {
  color: var(--text-primary);
  background: rgba(0,229,255,0.03);
}

.teach-tab.active {
  color: var(--accent-cyan);
  border-bottom-color: var(--accent-cyan);
}

.tab-icon { font-size: 1.1rem; }

/* --- Content Area --- */
.teach-content {
  position: relative;
  z-index: 1;
  max-width: 1000px;
  margin: 0 auto;
  padding: 3rem 2rem 4rem;
}

.teach-section {
  display: none;
}

.teach-section.active {
  display: block;
  animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* --- Section Header --- */
.teach-section-header {
  display: flex;
  align-items: flex-start;
  gap: 1.2rem;
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-glass);
}

.section-icon {
  font-size: 3rem;
  line-height: 1;
}

.teach-section-header h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 2px;
  margin-bottom: 0.4rem;
}

.teach-section-header p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* --- Teach Card --- */
.teach-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 1.5rem;
  backdrop-filter: blur(8px);
  transition: all 0.3s ease;
}

.teach-card:hover {
  border-color: rgba(0,229,255,0.15);
}

.teach-card h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 1px;
  margin-bottom: 1.2rem;
}

/* --- Level Badge --- */
.teach-level {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 1rem;
  font-family: var(--font-display);
}

.level-basic {
  background: rgba(16,185,129,0.15);
  color: var(--accent-green);
  border: 1px solid rgba(16,185,129,0.3);
}

.level-intermediate {
  background: rgba(59,130,246,0.15);
  color: var(--accent-blue);
  border: 1px solid rgba(59,130,246,0.3);
}

.level-advanced {
  background: rgba(168,85,247,0.15);
  color: var(--accent-purple);
  border: 1px solid rgba(168,85,247,0.3);
}

/* --- Example --- */
.teach-example {
  background: rgba(0,0,0,0.3);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  padding: 1.2rem 1.5rem;
  margin-bottom: 1.2rem;
}

.example-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-green);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.teach-example code {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--text-primary);
  line-height: 1.7;
  display: block;
  word-break: break-all;
}

/* --- Compare --- */
.teach-compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.2rem;
}

.compare-bad, .compare-good {
  padding: 1rem 1.2rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
}

.compare-bad {
  background: rgba(239,68,68,0.08);
  border: 1px solid rgba(239,68,68,0.2);
}

.compare-good {
  background: rgba(16,185,129,0.08);
  border: 1px solid rgba(16,185,129,0.2);
}

.compare-label {
  display: block;
  font-size: 0.78rem;
  font-weight: 700;
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.compare-bad .compare-label { color: #ef4444; }
.compare-good .compare-label { color: var(--accent-green); }

.compare-bad p, .compare-good p {
  color: var(--text-secondary);
  line-height: 1.6;
  font-size: 0.85rem;
}

/* --- Tips --- */
.teach-tips {
  background: rgba(0,229,255,0.04);
  border: 1px solid rgba(0,229,255,0.1);
  border-radius: var(--radius-md);
  padding: 1.2rem 1.5rem;
}

.tip-badge {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent-cyan);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 10px;
}

.teach-tips ul {
  list-style: none;
  padding: 0;
}

.teach-tips li {
  position: relative;
  padding-left: 1.5rem;
  margin-bottom: 6px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.teach-tips li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--accent-cyan);
  font-weight: 700;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .page-header { padding: 100px 1.5rem 30px; }
  
  .teach-nav { padding: 0 1rem; }
  .teach-tab { padding: 12px 14px; font-size: 0.82rem; }
  
  .teach-content { padding: 2rem 1.5rem; }
  .teach-card { padding: 1.5rem; }
  
  .teach-section-header {
    flex-direction: column;
    gap: 0.8rem;
  }
  
  .teach-compare {
    grid-template-columns: 1fr;
  }
}