/* ============================================
   Responsive Styles - Mobile First
   ============================================ */

/* Tablet and below */
@media (max-width: 1024px) {
  .highlights {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .metrics__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-5);
  }
  
  .dataset-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .paper-card {
    grid-template-columns: 1fr;
  }
  
  .paper-preview {
    padding: var(--space-4);
  }
  
  .footer__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Mobile */
@media (max-width: 768px) {
  :root {
    --nav-height: 56px;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .container {
    padding: 0 var(--space-4);
  }
  
  /* Navigation */
  .nav__links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-4);
    background: var(--color-bg);
    border-top: 1px solid var(--color-border);
    transform: translateX(100%);
    transition: transform var(--duration-normal) var(--ease-out);
    overflow-y: auto;
  }
  
  .nav__links.open {
    transform: translateX(0);
  }
  
  .nav__link {
    padding: var(--space-4);
    font-size: 1rem;
    border-bottom: 1px solid var(--color-divider);
  }
  
  .nav__toggle {
    display: flex;
  }
  
  .nav__toggle.open span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }
  
  .nav__toggle.open span:nth-child(2) {
    opacity: 0;
  }
  
  .nav__toggle.open span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }
  
  /* Hero */
  .hero {
    padding: calc(var(--nav-height) + var(--space-10)) 0 var(--space-10);
  }
  
  .hero__title {
    font-size: 1.75rem;
  }
  
  .hero__subtitle {
    font-size: 1rem;
  }
  
  .hero__actions {
    flex-direction: column;
    align-items: center;
  }
  
  .btn {
    width: 100%;
    justify-content: center;
    max-width: 280px;
  }
  
  /* Metrics */
  .metrics__grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4);
  }
  
  .metric__value {
    font-size: 1.75rem;
  }
  
  .metric__label {
    font-size: 0.75rem;
  }
  
  /* Sections */
  .section {
    padding: var(--space-10) 0;
  }
  
  .section__header {
    margin-bottom: var(--space-6);
  }
  
  /* Highlights */
  .highlights {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }
  
  .card {
    padding: var(--space-5);
  }
  
  /* Results */
  .results__tabs {
    margin-bottom: var(--space-4);
    gap: 0;
  }
  
  .tab-btn {
    padding: var(--space-3);
    font-size: 0.8125rem;
  }
  
  /* Demo */
  .demo-frame {
    height: 500px;
  }
  
  .demo-header {
    flex-direction: column;
    gap: var(--space-3);
    align-items: flex-start;
  }
  
  /* Dataset */
  .dataset-stats {
    grid-template-columns: 1fr 1fr;
  }
  
  .stat-card__value {
    font-size: 1.5rem;
  }
  
  /* Citation */
  .citation-box {
    padding: var(--space-4);
    padding-top: var(--space-10);
  }
  
  .citation-box pre {
    font-size: 0.75rem;
  }
  
  .citation-copy {
    top: var(--space-3);
    right: var(--space-3);
  }
  
  /* Footer */
  .footer {
    padding: var(--space-8) 0 var(--space-5);
  }
  
  .footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
  
  .footer__bottom {
    flex-direction: column;
    gap: var(--space-4);
    text-align: center;
  }
  
  /* Back to Top */
  .back-to-top {
    bottom: var(--space-4);
    right: var(--space-4);
    width: 40px;
    height: 40px;
  }
}

/* Small Mobile */
@media (max-width: 480px) {
  .hero__badge {
    font-size: 0.75rem;
    padding: var(--space-1) var(--space-3);
  }
  
  .metrics__grid {
    gap: var(--space-3);
  }
  
  .metric__value {
    font-size: 1.5rem;
  }
  
  .data-table {
    font-size: 0.8125rem;
  }
  
  .data-table th,
  .data-table td {
    padding: var(--space-2) var(--space-3);
  }
  
  .paper-info__actions {
    flex-direction: column;
  }
  
  .paper-info__actions .btn {
    max-width: 100%;
  }
}

/* Print Styles */
@media print {
  .nav,
  .back-to-top,
  .demo-container {
    display: none !important;
  }
  
  body {
    font-size: 12pt;
    line-height: 1.5;
  }
  
  .section {
    padding: 2rem 0;
    page-break-inside: avoid;
  }
  
  .card {
    border: 1px solid #ccc;
    box-shadow: none;
  }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* Dark Mode Support (optional enhancement) */
@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #1a1a1a;
    --color-surface: #242424;
    --color-surface-dark: #2a2a2a;
    --color-border: #3a3a3a;
    --color-divider: #333333;
    --color-text: #e8e8e8;
    --color-text-secondary: #a8a8a8;
    --color-text-tertiary: #888888;
  }
  
  .nav {
    background: rgba(26, 26, 26, 0.95);
  }
  
  .citation-box {
    background: #0a0a0a;
  }
  
  .result-figure img {
    border-color: var(--color-border);
  }
}