/* ==========================================================================
   RESPONSIVE DESIGN SYSTEM
   Mosaidur Rahman Asif — Personal Portfolio
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Large Tablets & Small Laptops (<= 1024px)
   -------------------------------------------------------------------------- */
@media (max-width: 1180px) {
  .nav-menu {
    gap: 0.7rem;
  }

  .nav-link {
    font-size: 0.8125rem;
  }

  .brand-mark {
    height: 34px;
  }

  .brand-name {
    font-size: 0.84rem;
  }
}

@media (max-width: 980px) {
  .brand-divider,
  .brand-text {
    display: none;
  }
}

@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3.5rem;
    text-align: center;
  }

  .hero-content {
    align-items: center;
    text-align: center;
  }

  .hero-roles-banner {
    justify-content: center;
  }

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

  .hero-visual {
    order: -1;
    margin-bottom: 1rem;
  }

  .hero-card-wrapper {
    max-width: 380px;
  }

  .hero-image-frame {
    height: 420px;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .featured-grid {
    grid-template-columns: 1fr;
  }

  .featured-visual {
    min-height: 280px;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .edu-awards-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .certs-grid {
    grid-template-columns: 1fr;
  }

  .footer-top-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
  }
}

/* --------------------------------------------------------------------------
   2. Tablets & Mobile Landscape (<= 768px)
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
  .nav-menu {
    display: none;
  }

  .mobile-menu-toggle {
    display: flex;
  }

  .nav-actions .btn-sm {
    display: none;
  }

  .brand-mark {
    height: 34px;
  }

  .brand-name {
    font-size: 0.82rem;
  }

  .brand-role {
    font-size: 0.68rem;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
  }

  .timeline {
    padding-left: 1.5rem;
  }

  .timeline::before {
    left: 4px;
  }

  .timeline-dot {
    left: -1.5rem;
    top: 1rem;
    width: 14px;
    height: 14px;
  }

  .timeline-card {
    padding: 1.25rem;
  }

  .form-row {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .footer-top-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

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

  .badge-top-right {
    top: -10px;
    right: -10px;
    padding: 0.6rem 0.9rem;
  }

  .badge-bottom-left {
    bottom: -10px;
    left: -10px;
    padding: 0.6rem 0.9rem;
  }

  .badge-metric {
    font-size: 1.25rem;
  }

  .badge-label {
    font-size: 0.6875rem;
  }
}

@media (max-width: 520px) {
  .brand-divider,
  .brand-text {
    display: none;
  }

  .brand-mark {
    height: 36px;
  }
}

/* --------------------------------------------------------------------------
   3. Small Mobile Devices (<= 480px)
   -------------------------------------------------------------------------- */
@media (max-width: 480px) {
  :root {
    --section-spacing-y: 3.75rem;
  }

  .container {
    padding-left: 1.25rem;
    padding-right: 1.25rem;
  }

  .hero-headline {
    font-size: 2.25rem;
  }

  .hero-card-wrapper {
    max-width: 320px;
  }

  .hero-image-frame {
    height: 360px;
  }

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

  .projects-grid,
  .research-grid,
  .leadership-grid,
  .recommendations-grid,
  .services-grid,
  .skills-category-grid {
    grid-template-columns: 1fr;
  }

  .btn {
    width: 100%;
  }

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

  .project-filter-bar {
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 0.5rem;
    flex-wrap: nowrap;
    -webkit-overflow-scrolling: touch;
  }

  .filter-btn {
    flex-shrink: 0;
  }
}