/* ============================================================
   responsive.css — Media Queries for Robotics Platform
   ============================================================ */

/* ─── 1200px ────────────────────────────────────────────────── */
@media (max-width: 1200px) {
  .grid-4 {
    grid-template-columns: repeat(3, 1fr);
  }

  .footer__grid {
    grid-template-columns: 2fr 1fr 1fr;
  }
}

/* ─── 992px ─────────────────────────────────────────────────── */
@media (max-width: 992px) {
  :root {
    --section-padding: 80px;
  }

  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  /* Hero: single column */
  .hero__container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero__content {
    order: 1;
  }

  .hero__visual {
    display: none;
  }

  .hero__actions {
    justify-content: center;
  }

  .hero__subtitle {
    max-width: 100%;
  }

  .hero__stats {
    grid-template-columns: repeat(2, 1fr);
  }

  /* About */
  .about-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .about-visual {
    display: none;
  }

  /* Footer */
  .footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  /* Timeline: single column */
  .timeline-line {
    left: 16px;
  }

  .timeline-item {
    width: 100%;
    padding-right: 0;
    padding-left: 48px;
    justify-content: flex-start;
  }

  .timeline-item--right {
    margin-left: 0;
    padding-left: 48px;
    padding-right: 0;
  }

  .timeline-item__marker {
    right: auto;
    left: 8px;
  }

  .timeline-item--right .timeline-item__marker {
    left: 8px;
  }

  .timeline-item__content {
    max-width: 100%;
  }
}

/* ─── 768px ─────────────────────────────────────────────────── */
@media (max-width: 768px) {
  :root {
    --section-padding: 64px;
    --navbar-height: 64px;
  }

  /* Mobile Nav: slide-in panel */
  .nav-links {
    position: fixed;
    top: var(--navbar-height);
    right: -100%;
    width: 280px;
    height: calc(100vh - var(--navbar-height));
    background: var(--color-bg-dark);
    border-left: 1px solid var(--color-border);
    flex-direction: column;
    padding: 32px 24px;
    gap: 4px;
    transition: right 0.35s ease;
    z-index: 999;
    align-items: flex-start;
    overflow-y: auto;
  }

  .nav-links.active {
    right: 0;
    box-shadow: -8px 0 32px rgba(0, 0, 0, 0.4);
  }

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

  .nav-link {
    font-size: 1rem;
    padding: 12px 16px;
    width: 100%;
    border-radius: var(--radius-sm);
  }

  .hamburger {
    display: flex;
  }

  /* All grids → 1 column */
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  /* Hero */
  .hero__container {
    padding: 20px 24px;
    gap: 32px;
  }

  .hero__stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-top: 40px;
    padding-top: 24px;
  }

  .hero__stat-value {
    font-size: 1.6rem;
  }

  /* Section header */
  .section-header {
    margin-bottom: 40px;
  }

  /* About features */
  .about-features {
    grid-template-columns: 1fr;
  }

  /* Filters: horizontal scroll */
  .filter-tabs {
    flex-wrap: nowrap;
    overflow-x: auto;
    justify-content: flex-start;
    padding-bottom: 10px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .filter-tabs::-webkit-scrollbar {
    display: none;
  }

  .difficulty-filters {
    flex-wrap: wrap;
    justify-content: center;
  }

  /* Pipeline: vertical */
  .pipeline-steps {
    flex-direction: column;
    gap: 8px;
    width: 100%;
  }

  .pipeline-arrow {
    transform: rotate(90deg);
    padding: 0;
  }

  .pipeline-step {
    width: 100%;
    text-align: center;
    min-width: unset;
  }

  /* Footer */
  .footer__grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer__bottom {
    flex-direction: column;
    text-align: center;
    gap: 8px;
  }

  /* System pipeline container */
  .system-pipeline {
    padding: 28px 20px;
  }

  /* Contact */
  .contact-actions {
    flex-direction: column;
    align-items: center;
  }

  /* Search modal */
  .search-modal {
    padding-top: 80px;
  }

  /* Post detail */
  .post-detail {
    padding-top: calc(var(--navbar-height) + 32px);
  }

  .post-detail__title {
    font-size: 1.75rem;
  }

  .post-detail__content h2 {
    font-size: 1.35rem;
  }

  .post-detail__meta {
    flex-direction: column;
    gap: 8px;
  }
}

/* ─── 480px ─────────────────────────────────────────────────── */
@media (max-width: 480px) {
  :root {
    --section-padding: 52px;
  }

  .hero__stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .hero__stat-value {
    font-size: 1.4rem;
  }

  .btn--lg {
    padding: 14px 28px;
    font-size: 1rem;
  }

  .section-title {
    font-size: 1.6rem;
  }

  .contact-social {
    gap: 10px;
  }

  .timeline-item {
    padding-left: 40px;
  }

  .post-detail {
    padding-left: 16px;
    padding-right: 16px;
  }

  .about-features {
    gap: 12px;
  }

  .nav-logo__text {
    display: none;
  }

  .footer__grid {
    gap: 24px;
  }
}