/* ==========================================================================
   VTN GROUP - PREMIUM MOBILE & TABLET RESPONSIVE BREAKPOINTS
   ========================================================================== */

/* Laptop / Desktop Medium (1200px) */
@media (max-width: 1200px) {
  .header-container {
    max-width: 100%;
    padding: 0 1.5rem;
  }
}

/* Tablet & Mobile Drawer Navigation (991px) */
@media (max-width: 991px) {
  .site-header {
    background-color: rgba(7, 25, 47, 0.98);
  }

  .header-container {
    height: 76px;
  }

  .main-navigation {
    position: fixed;
    top: 76px;
    right: 0;
    width: 85%;
    max-width: 320px;
    height: calc(100vh - 76px);
    background: linear-gradient(180deg, #07192f 0%, #0b2545 100%);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    padding: 2rem 1.5rem;
    box-shadow: -10px 20px 40px rgba(0, 0, 0, 0.5);
    border-left: 1px solid rgba(59, 130, 246, 0.25);
    transform: translateX(100%);
    transition: transform 0.35s cubic-bezier(0.25, 0.8, 0.25, 1);
    visibility: hidden;
    overflow-y: auto;
    z-index: 999;
  }

  .main-navigation.is-open {
    transform: translateX(0);
    visibility: visible;
  }

  .nav-menu {
    flex-direction: column;
    align-items: stretch;
    width: 100%;
    gap: 0.5rem;
  }

  .nav-menu li {
    width: 100%;
  }

  .nav-menu a {
    padding: 0.85rem 1rem;
    font-size: 1.02rem;
    color: #f1f5f9;
    border-radius: 8px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition);
  }

  .nav-menu a::after {
    display: none;
  }

  .nav-menu a:hover,
  .nav-menu .current-menu-item > a {
    background: rgba(37, 99, 235, 0.2);
    color: #60a5fa;
  }

  .mobile-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(59, 130, 246, 0.3);
    color: #ffffff;
    font-size: 1.4rem;
  }

  /* Hero Section Mobile Adjustment */
  .hero-section {
    padding: 140px 0 70px 0;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
    text-align: center;
  }

  .hero-subtitle {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-ctas {
    justify-content: center;
  }

  .hero-media-wrapper img {
    height: 380px;
  }

  /* Grid Layouts */
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 2.5rem;
  }
}

/* Smartphone Portrait (576px) */
@media (max-width: 576px) {
  .header-container {
    height: 68px;
  }

  .main-navigation {
    top: 68px;
    height: calc(100vh - 68px);
    width: 90%;
  }

  .site-logo img {
    height: 44px;
  }

  .header-actions .btn-sm {
    padding: 0.5rem 0.9rem;
    font-size: 0.8rem;
  }

  .hero-section {
    padding: 120px 0 50px 0;
  }

  .hero-title {
    font-size: 2.1rem;
  }

  .hero-subtitle {
    font-size: 1.02rem;
  }

  .hero-ctas {
    flex-direction: column;
    width: 100%;
  }

  .hero-ctas .btn {
    width: 100%;
  }

  .hero-media-wrapper img {
    height: 280px;
  }

  .hero-badge-floating {
    position: relative;
    bottom: auto;
    left: auto;
    margin-top: 15px;
    border-radius: 14px;
    padding: 14px 18px;
  }

  /* Section Padding for Mobile */
  .section {
    padding: 3.8rem 0;
  }

  .section-title {
    font-size: 1.75rem;
  }

  /* Founder Section Mobile */
  #founder .grid-2 {
    gap: 2.5rem;
  }

  #founder img {
    height: 380px !important;
  }

  /* Footer Mobile */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2.2rem;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}