/* ========================================
   Navigation
   ======================================== */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  background-color: rgba(10, 14, 23, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
}

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

.nav__brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}

.nav__brand:hover {
  color: var(--accent-blue);
}

.nav__brand-icon {
  width: 1.75rem;
  height: 1.75rem;
  color: var(--accent-green);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav__link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.nav__link:hover {
  color: var(--text-primary);
}

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--space-sm);
}

.nav__toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--text-primary);
  border-radius: 1px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

@media (max-width: 48em) {
  .nav__toggle {
    display: flex;
  }

  .nav__links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    padding: var(--space-lg);
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
  }

  .nav__links--open {
    display: flex;
  }

  .nav__link {
    font-size: var(--text-base);
    padding: var(--space-sm) 0;
  }
}

/* Toggle active state */
.nav__toggle--active .nav__toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav__toggle--active .nav__toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav__toggle--active .nav__toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ========================================
   Hero
   ======================================== */

.hero {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 85vh;
  padding-top: var(--nav-height);
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(59, 130, 246, 0.08) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 20%, rgba(16, 185, 129, 0.06) 0%, transparent 50%);
  pointer-events: none;
}

.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(59, 130, 246, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(59, 130, 246, 0.03) 1px, transparent 1px);
  background-size: 4rem 4rem;
  pointer-events: none;
}

.hero__content {
  position: relative;
  max-width: 42rem;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-xs) var(--space-md);
  margin-bottom: var(--space-lg);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--accent-green);
  background-color: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.2);
  border-radius: 9999px;
}

.hero__title {
  margin-bottom: var(--space-lg);
}

.hero__title-accent {
  color: var(--accent-blue);
}

.hero__description {
  font-size: var(--text-lg);
  margin-bottom: var(--space-xl);
  max-width: 38rem;
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

/* ========================================
   Buttons
   ======================================== */

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 0.75rem 1.5rem;
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn--primary {
  color: #fff;
  background-color: var(--accent-blue);
}

.btn--primary:hover {
  background-color: var(--accent-blue-hover);
  color: #fff;
}

.btn--secondary {
  color: var(--text-primary);
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
}

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

.btn--amber {
  color: #000;
  background-color: var(--accent-amber);
}

.btn--amber:hover {
  background-color: var(--accent-amber-hover);
  color: #000;
}

/* ========================================
   Cards
   ======================================== */

.card {
  display: flex;
  flex-direction: column;
  padding: var(--space-lg);
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  transition: border-color var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
  text-decoration: none;
  color: inherit;
}

.card:hover {
  border-color: var(--border-color-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  color: inherit;
}

.card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  margin-bottom: var(--space-md);
  border-radius: var(--radius-md);
  font-size: 1.25rem;
}

.card__icon--blue {
  background-color: rgba(59, 130, 246, 0.1);
  color: var(--accent-blue);
}

.card__icon--green {
  background-color: rgba(16, 185, 129, 0.1);
  color: var(--accent-green);
}

.card__icon--amber {
  background-color: rgba(245, 158, 11, 0.1);
  color: var(--accent-amber);
}

.card__icon--red {
  background-color: rgba(239, 68, 68, 0.1);
  color: var(--accent-red);
}

.card__title {
  font-size: var(--text-lg);
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.card__org {
  font-size: var(--text-xs);
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.card__description {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  flex: 1;
}

.card__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid var(--border-color);
}

.card__link-text {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--accent-blue);
}

.card:hover .card__link-text {
  color: var(--accent-blue-hover);
}

.card__arrow {
  transition: transform var(--transition-fast);
}

.card:hover .card__arrow {
  transform: translateX(3px);
}

/* Badge for difficulty levels */
.badge {
  display: inline-block;
  padding: 0.125rem 0.5rem;
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: 9999px;
}

.badge--beginner {
  background-color: rgba(16, 185, 129, 0.1);
  color: var(--accent-green);
}

.badge--intermediate {
  background-color: rgba(59, 130, 246, 0.1);
  color: var(--accent-blue);
}

.badge--advanced {
  background-color: rgba(245, 158, 11, 0.1);
  color: var(--accent-amber);
}

.badge--all {
  background-color: rgba(139, 92, 246, 0.1);
  color: #a78bfa;
}

/* ========================================
   YouTube Facade
   ======================================== */

.youtube-facade {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%; /* 16:9 */
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-lg);
  overflow: hidden;
  cursor: pointer;
}

.youtube-facade__thumb {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.youtube-facade__play {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 4.5rem;
  height: 3.25rem;
  background-color: rgba(255, 0, 0, 0.85);
  border-radius: var(--radius-lg);
  transition: background-color var(--transition-fast);
}

.youtube-facade__play::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 55%;
  transform: translate(-50%, -50%);
  border-style: solid;
  border-width: 0.625rem 0 0.625rem 1rem;
  border-color: transparent transparent transparent #fff;
}

.youtube-facade:hover .youtube-facade__play {
  background-color: rgba(255, 0, 0, 1);
}

.youtube-facade iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* ========================================
   Newsletter
   ======================================== */

.newsletter {
  text-align: center;
}

.newsletter__form {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-sm);
  max-width: 28rem;
  margin-inline: auto;
  margin-top: var(--space-xl);
}

.newsletter__input {
  flex: 1;
  min-width: 12rem;
  padding: 0.75rem 1rem;
  font-size: var(--text-base);
  font-family: var(--font-sans);
  color: var(--text-primary);
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast);
}

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

.newsletter__input:focus {
  outline: none;
  border-color: var(--accent-blue);
}

.newsletter__note {
  margin-top: var(--space-md);
  font-size: var(--text-sm);
  color: var(--text-muted);
}

/* ========================================
   Footer
   ======================================== */

.footer {
  padding-block: var(--space-2xl);
  border-top: 1px solid var(--border-color);
}

.footer__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.footer__copy {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

.footer__links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.footer__link {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--text-primary);
}

/* ========================================
   About Section
   ======================================== */

.about__content {
  display: grid;
  gap: var(--space-2xl);
  align-items: start;
}

@media (min-width: 48em) {
  .about__content {
    grid-template-columns: 1fr 1fr;
  }
}

.about__text p {
  margin-bottom: var(--space-md);
}

.about__credentials {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-top: var(--space-lg);
}

.credential-tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-md);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--accent-green);
  background-color: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.15);
  border-radius: 9999px;
}