/* ============================================================
   responsive.css — Karpathy-style Minimal Responsive
   Single-column focus, minimal breakpoint changes
   ============================================================ */

/* ============================================================
   Tablet & Desktop (>= 768px)
   ============================================================ */

@media (min-width: 768px) {
  .hamburger { display: none; }
  .nav-list { display: flex; }

  .about-layout {
    flex-direction: row;
    gap: var(--sp-2xl);
  }

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

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

/* ============================================================
   Mobile (< 768px)
   ============================================================ */

@media (max-width: 767px) {
  html {
    scroll-padding-top: 48px;
  }

  .container {
    padding-inline: var(--sp-md);
  }

  /* Hero */
  .hero-banner {
    height: 240px;
  }

  .hero-title {
    font-size: 1.23rem;
  }

  .hero-subtitle {
    font-size: 0.96rem;
  }

  .hero-tagline {
    font-size: 0.85rem;
    line-height: 1.9;
    margin-top: var(--sp-sm);
    max-width: 90%;
  }

  /* Header */
  .header-inner {
    flex-wrap: wrap;
    padding-block: var(--sp-sm);
  }

  .site-title {
    font-size: 0.8125rem;
  }

  .hamburger {
    display: flex;
  }

  .site-nav {
    display: none;
    width: 100%;
    order: 3;
    border-top: 1px solid var(--color-border);
    padding-top: var(--sp-sm);
  }

  .site-nav.open {
    display: block;
  }

  .nav-list {
    flex-direction: column;
    gap: 0;
  }

  .nav-link {
    display: block;
    padding: var(--sp-sm) 0;
    font-size: 0.875rem;
    border-bottom: 1px solid var(--color-border);
  }

  .nav-link:last-child {
    border-bottom: none;
  }

  /* Sections */
  section {
    padding-block: var(--sp-xl);
  }

  .section-heading {
    font-size: 1.25rem;
  }

  /* About */
  .about-layout {
    flex-direction: column;
    gap: var(--sp-lg);
  }

  .about-photo-col {
    display: flex;
    justify-content: center;
  }

  .profile-photo {
    width: 140px;
  }

  .prof-name-ko {
    font-size: 1.5rem;
    text-align: center;
  }

  .prof-name-en {
    text-align: center;
  }

  .prof-meta-row {
    flex-direction: column;
    gap: 0;
  }

  .prof-meta-row dt {
    width: auto;
    font-size: 0.75rem;
  }

  /* Publications */
  .pub-item {
    flex-direction: column;
    gap: var(--sp-xs);
  }

  .filter-bar {
    flex-wrap: wrap;
    gap: 0;
  }

  .filter-btn {
    font-size: 0.75rem;
    padding: var(--sp-xs) var(--sp-sm);
  }

  /* Teaching */
  .course-grid {
    gap: var(--sp-md);
  }

  .course-meta-row {
    flex-direction: column;
    gap: 0;
  }

  /* Lab */
  .members-grid {
    grid-template-columns: 1fr;
  }

  .alumni-item {
    flex-direction: column;
    gap: 2px;
  }

  .alumni-position {
    margin-left: 0;
  }

  /* News */
  .news-item {
    flex-direction: column;
    gap: var(--sp-xs);
  }

  .news-meta {
    display: flex;
    gap: var(--sp-sm);
    align-items: center;
    min-width: 0;
  }

  /* Contact */
  .contact-cards {
    grid-template-columns: 1fr;
  }

  /* Footer */
  .footer-inner {
    flex-direction: column;
    gap: var(--sp-md);
  }

  .footer-meta {
    text-align: left;
  }

  .footer-contact-list {
    flex-direction: column;
    gap: var(--sp-xs);
  }
}