/* ==========================================================================
   Basic Mechanical Engineering - Components (components.css)
   Navbar, Hero, Cards, Search, Modals, Footer
   Theme: Netflix Red & Dark Brown
   ========================================================================== */

/* Navbar */
.navbar {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  z-index: 1000;
  transition: background var(--transition-normal), border-color var(--transition-normal);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-family: 'Outfit', sans-serif;
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--text-primary);
  text-decoration: none;
  cursor: pointer;
}

.brand-gear {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, #E50914, #b81d24);
  color: white;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: 0 4px 14px var(--primary-glow);
  transition: transform var(--transition-normal);
}

.brand-logo:hover .brand-gear {
  transform: rotate(45deg);
}

.brand-name {
  color: var(--text-primary);
  font-weight: 800;
}

.brand-badge {
  font-size: 0.65rem;
  font-weight: 700;
  padding: 0.2rem 0.5rem;
  background: var(--primary-50);
  color: var(--primary-600);
  border: 1px solid var(--primary-100);
  border-radius: var(--radius-sm);
  letter-spacing: 0.04em;
}

body.dark-theme .brand-badge,
[data-theme="dark"] .brand-badge {
  background: rgba(229, 9, 20, 0.2);
  color: #ff4d52;
  border-color: rgba(229, 9, 20, 0.35);
}

.nav-links {
  display: none;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}

@media (min-width: 992px) {
  .nav-links {
    display: flex;
  }
}

.nav-link {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  cursor: pointer;
  text-decoration: none;
}

.nav-link:hover, .nav-link.active {
  color: var(--primary-600);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Search Trigger Button */
.search-trigger-btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 0.85rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-full);
  color: var(--text-muted);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.search-trigger-btn:hover {
  background: var(--bg-surface);
  border-color: var(--primary-600);
  color: var(--text-primary);
  box-shadow: 0 0 10px var(--primary-glow);
}

.search-kbd {
  font-size: 0.75rem;
  padding: 0.1rem 0.35rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
}

/* Mode Switches (Teacher Mode & Dark Theme) */
.toggle-icon-btn {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-subtle);
  border: 1px solid var(--border-medium);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 1.15rem;
  transition: all var(--transition-fast);
}

.toggle-icon-btn:hover {
  background: var(--bg-surface);
  border-color: var(--primary-600);
  color: var(--primary-600);
  transform: translateY(-1px);
}

.teacher-mode-btn {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.9rem;
  font-size: 0.8rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-medium);
  background: var(--bg-subtle);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.teacher-mode-btn:hover {
  border-color: var(--primary-600);
  color: var(--text-primary);
}

.teacher-mode-btn.active {
  background: linear-gradient(135deg, #E50914, #991b1b);
  color: #ffffff;
  border-color: transparent;
  box-shadow: 0 4px 14px var(--primary-glow);
}

/* Mobile Menu Button */
.mobile-menu-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  font-size: 1.4rem;
  color: var(--text-primary);
  cursor: pointer;
}

@media (min-width: 992px) {
  .mobile-menu-btn {
    display: none;
  }
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  position: relative;
  padding: 4rem 0 3rem;
  text-align: center;
  overflow: hidden;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1.1rem;
  background: var(--primary-50);
  border: 1px solid var(--primary-100);
  border-radius: var(--radius-full);
  color: var(--primary-600);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  box-shadow: 0 2px 8px var(--primary-glow);
}

body.dark-theme .hero-pill,
[data-theme="dark"] .hero-pill {
  background: rgba(229, 9, 20, 0.15);
  border-color: rgba(229, 9, 20, 0.35);
  color: #ff4d52;
}

.hero-title {
  max-width: 900px;
  margin: 0 auto 1.25rem;
  font-size: clamp(2.25rem, 5.5vw, 3.75rem);
}

.gradient-text {
  background: linear-gradient(135deg, #E50914, #ff333a, #ff7849);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

body.dark-theme .gradient-text,
[data-theme="dark"] .gradient-text {
  background: linear-gradient(135deg, #ff333a, #ff6b6b, #ffa07a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  max-width: 720px;
  margin: 0 auto 2rem;
  font-size: 1.15rem;
  color: var(--text-secondary);
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 3rem;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 1.75rem;
  background: linear-gradient(135deg, #E50914, #b81d24);
  color: #ffffff;
  font-weight: 700;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 16px var(--primary-glow);
  transition: all var(--transition-fast);
  border: none;
  cursor: pointer;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--primary-glow);
  color: #ffffff;
  background: linear-gradient(135deg, #f40612, #E50914);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 1.75rem;
  background: var(--bg-surface);
  color: var(--text-primary);
  font-weight: 600;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-medium);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.btn-secondary:hover {
  background: var(--bg-subtle);
  border-color: var(--primary-600);
  color: var(--primary-600);
}

/* Quick Stats Bar */
.hero-stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  max-width: 900px;
  margin: 0 auto;
}

@media (min-width: 640px) {
  .hero-stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.stat-item {
  padding: 1.25rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  backdrop-filter: var(--glass-blur);
  text-align: center;
  transition: transform var(--transition-fast);
}

.stat-item:hover {
  transform: translateY(-3px);
  border-color: var(--border-medium);
}

.stat-number {
  font-family: 'Outfit', sans-serif;
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary-600);
  line-height: 1.1;
  margin-bottom: 0.25rem;
}

.stat-label {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ==========================================================================
   Course Progress Bar
   ========================================================================== */
.progress-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.75rem;
  margin-bottom: 2.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  box-shadow: var(--shadow-sm);
}

@media (min-width: 768px) {
  .progress-card {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.progress-info {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.progress-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--primary-50);
  color: var(--primary-600);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
}

body.dark-theme .progress-icon,
[data-theme="dark"] .progress-icon {
  background: rgba(229, 9, 20, 0.2);
  color: #ff4d52;
}

.progress-text h4 {
  font-size: 1.05rem;
  margin-bottom: 0.15rem;
}

.progress-text p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

.progress-bar-wrapper {
  flex: 1;
  max-width: 450px;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.progress-track {
  flex: 1;
  height: 10px;
  background: var(--bg-subtle);
  border-radius: var(--radius-full);
  overflow: hidden;
  position: relative;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #E50914, #ff5c60);
  border-radius: var(--radius-full);
  transition: width 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.progress-percentage {
  font-family: 'Outfit', sans-serif;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary-600);
  min-width: 50px;
  text-align: right;
}

/* ==========================================================================
   Units Showcase Grid
   ========================================================================== */
.units-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-bottom: 4rem;
}

@media (min-width: 768px) {
  .units-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1100px) {
  .units-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.unit-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  backdrop-filter: var(--glass-blur);
  transition: all var(--transition-normal);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.unit-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--primary-600);
  transition: height var(--transition-fast);
}

.unit-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary-600);
  box-shadow: 0 8px 24px var(--primary-glow);
}

.unit-card:hover::before {
  height: 6px;
}

.unit-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.unit-number-badge {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.25rem 0.65rem;
  background: var(--bg-subtle);
  color: var(--text-muted);
  border-radius: var(--radius-full);
}

.unit-co-badge {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.65rem;
  background: var(--primary-50);
  color: var(--primary-600);
  border-radius: var(--radius-full);
}

body.dark-theme .unit-co-badge,
[data-theme="dark"] .unit-co-badge {
  background: rgba(229, 9, 20, 0.2);
  color: #ff4d52;
}

.unit-title {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.unit-tagline {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--primary-600);
  margin-bottom: 0.85rem;
}

.unit-summary {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 1.5rem;
  flex: 1;
}

.unit-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

.unit-link-btn {
  color: var(--primary-600);
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

/* ==========================================================================
   Lecture Cards Grid & Filters
   ========================================================================== */
.lectures-section {
  padding: 3rem 0;
}

.filter-bar {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 2rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1rem 1.25rem;
  box-shadow: var(--shadow-sm);
}

@media (min-width: 768px) {
  .filter-bar {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.unit-filter-pills {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.filter-pill {
  padding: 0.4rem 0.85rem;
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: var(--bg-subtle);
  color: var(--text-secondary);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-pill:hover {
  background: var(--bg-surface-elevated);
  border-color: var(--border-medium);
  color: var(--text-primary);
}

.filter-pill.active {
  background: var(--primary-600);
  color: #ffffff;
  box-shadow: 0 2px 8px var(--primary-glow);
}

.filter-search-box {
  position: relative;
  width: 100%;
  max-width: 280px;
}

.filter-search-input {
  width: 100%;
  padding: 0.5rem 1rem 0.5rem 2.25rem;
  font-size: 0.9rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-medium);
  background: var(--bg-subtle);
  color: var(--text-primary);
  outline: none;
  transition: all var(--transition-fast);
}

.filter-search-input:focus {
  border-color: var(--border-focus);
  background: var(--bg-surface);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.filter-search-icon {
  position: absolute;
  left: 0.85rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Lecture Cards Grid */
.lectures-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

@media (min-width: 640px) {
  .lectures-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .lectures-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.lecture-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  backdrop-filter: var(--glass-blur);
  transition: all var(--transition-normal);
  text-decoration: none;
  color: inherit;
  position: relative;
  cursor: pointer;
}

.lecture-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary-600);
  box-shadow: 0 8px 24px var(--primary-glow);
}

.lecture-top-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.85rem;
}

.lecture-number {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.55rem;
  background: var(--bg-subtle);
  color: var(--text-muted);
  border-radius: var(--radius-sm);
}

.sim-tag {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.55rem;
  background: rgba(229, 9, 20, 0.2);
  color: #ff4d52;
  border-radius: var(--radius-full);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.lecture-card-title {
  font-size: 1.15rem;
  line-height: 1.35;
  margin-bottom: 0.65rem;
  transition: color var(--transition-fast);
  color: var(--text-primary);
}

.lecture-card:hover .lecture-card-title {
  color: var(--primary-600);
}

.lecture-card-summary {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 1.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.lecture-bottom-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.85rem;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.completed-check {
  width: 24px;
  height: 24px;
  border-radius: var(--radius-full);
  border: 1.5px solid var(--border-medium);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  color: transparent;
  font-size: 0.8rem;
  font-weight: 700;
}

.completed-check.checked {
  background: #10b981;
  border-color: #10b981;
  color: #ffffff;
}

/* ==========================================================================
   Course Outcomes & Objectives Modal / Tab
   ========================================================================== */
.outcomes-section {
  padding: 3rem 0;
  background: var(--bg-surface);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
}

.outcomes-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 768px) {
  .outcomes-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.outcome-card {
  background: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  display: flex;
  gap: 1rem;
}

.outcome-id {
  font-family: 'Outfit', sans-serif;
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--primary-600);
  min-width: 48px;
}

.outcome-body h5 {
  margin-bottom: 0.35rem;
  color: var(--text-primary);
}

.outcome-body p {
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.bloom-badge {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 0.15rem 0.5rem;
  background: rgba(229, 9, 20, 0.15);
  color: var(--primary-600);
  border-radius: var(--radius-sm);
  display: inline-block;
}

/* ==========================================================================
   Global Search Modal (Ctrl + K)
   ========================================================================== */
.search-modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(10, 6, 5, 0.85);
  backdrop-filter: blur(8px);
  z-index: 99999;
  display: none;
  align-items: flex-start;
  justify-content: center;
  padding: 5rem 1rem 1rem;
}

.search-modal-backdrop.open {
  display: flex !important;
}

.search-modal-content {
  width: 100%;
  max-width: 680px;
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  animation: modalSlideDown 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalSlideDown {
  from { opacity: 0; transform: translateY(-15px); }
  to { opacity: 1; transform: translateY(0); }
}

.search-modal-header {
  display: flex;
  align-items: center;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border-subtle);
  gap: 0.75rem;
  background: var(--bg-surface-elevated);
}

.search-modal-input {
  flex: 1;
  border: none;
  background: transparent;
  font-size: 1.15rem;
  font-family: inherit;
  color: var(--text-primary);
  outline: none;
}

.search-modal-close {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.25rem;
  line-height: 1;
}

.search-modal-close:hover {
  color: var(--primary-600);
}

.search-results-list {
  max-height: 440px;
  overflow-y: auto;
  padding: 0.75rem;
}

.search-result-item {
  display: flex;
  flex-direction: column;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-md);
  text-decoration: none;
  color: var(--text-primary);
  transition: background var(--transition-fast);
  margin-bottom: 0.4rem;
  border: 1px solid transparent;
}

.search-result-item:hover, .search-result-item.selected {
  background: var(--bg-subtle);
  border-color: var(--border-medium);
}

.search-result-title {
  font-weight: 700;
  font-size: 0.98rem;
  margin-bottom: 0.2rem;
  color: var(--primary-600);
}

.search-result-snippet {
  font-size: 0.84rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  margin-top: auto;
  background: var(--bg-surface);
  border-top: 1px solid var(--border-subtle);
  padding: 3.5rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }
}

.footer-brand p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  margin-top: 0.75rem;
  max-width: 320px;
}

.footer-col h5 {
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links a {
  font-size: 0.88rem;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--primary-600);
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  align-items: center;
  justify-content: space-between;
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.85rem;
  color: var(--text-muted);
  text-align: center;
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
    text-align: left;
  }
}

.author-credit strong {
  color: var(--primary-600);
}