/* wenxin-responsive.css - 响应式：移动端断点、侧栏遮罩、触摸适配 */
/* Breakpoints: >1024px desktop, 861-1024px wide tablet,
   640-860px narrow tablet, <640px mobile (single-column) */

@media (max-width: 1024px) {
  :root {
    --text-5xl: 3.5rem;
    --text-4xl: 2.5rem;
  }
}

@media (max-width: 1024px) and (min-width: 861px) {
  body:not(.page-post) .page-layout {
    grid-template-columns: clamp(220px, 24vw, 260px) 1fr;
    gap: var(--space-16);
    padding: var(--space-16) clamp(20px, 3.5vw, 48px);
  }
  /* Sticky top must match layout padding-top */
  .sidebar {
    top: var(--space-16);
    gap: var(--space-10);
  }
  .brand-area .site-title { font-size: 2.75rem; }
  .sidebar-footer { display: none; }
}

@media (max-width: 860px) and (min-width: 640px) {
  body:not(.page-post) .page-layout {
    grid-template-columns: clamp(200px, 23vw, 230px) 1fr;
    gap: var(--space-12);
    padding: var(--space-12) clamp(16px, 3vw, 36px);
  }
  /* Sticky top must match layout padding-top */
  .sidebar {
    top: var(--space-12);
    gap: var(--space-8);
  }
  .brand-area .site-title { font-size: 2.5rem; }
  /* Narrow sidebar: allow bio text to wrap instead of overflow */
  .bio { white-space: normal; }
  .sidebar-footer { display: none; }
}

@media (max-width: 639px) {
  body:not(.page-post) .page-layout {
    grid-template-columns: 1fr;
    gap: var(--space-6);
    padding-top: var(--space-6);
    padding-bottom: var(--space-8);
  }

  body:not(.page-post) .sidebar {
    position: static;
    min-height: 0;
    border-bottom: 1px solid var(--color-border-subtle);
    padding-bottom: var(--space-4);
    gap: var(--space-3);
  }
  .brand-area .site-title {
    font-size: 1.75rem;
    margin-bottom: var(--space-2);
  }
  .brand-mark { width: 6px; height: 6px; }
  .bio {
    white-space: normal;
    font-size: var(--text-sm);
    line-height: var(--leading-normal);
  }

  /* Horizontal nav: active state becomes underline instead of leading dash */
  .site-nav {
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--space-6);
  }
  .site-nav a::before { display: none; }
  .site-nav a {
    border-bottom: 1px solid transparent;
    padding-bottom: 1px;
    transition: border-color var(--duration-fast), color var(--duration-fast);
  }
  .site-nav a.active,
  .site-nav a:hover {
    border-bottom-color: var(--color-accent);
  }

  .sidebar-footer { display: none; }

  /* Suppress iOS long-press context menu on links */
  a { -webkit-touch-callout: none; }
  /* Prevent accidental text selection on nav/brand during rapid tapping */
  .site-nav,
  .brand-area { -webkit-user-select: none; user-select: none; }

  :root {
    --text-xl:  1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.625rem;
    --text-4xl: 2rem;
    --text-5xl: 2.5rem;
  }
}

/* WCAG 2.5.5: minimum touch target size 44×44px */
@media (pointer: coarse) {
  .site-nav a {
    min-height: 44px;
    display: flex;
    align-items: center;
    padding-block: var(--space-2);
  }

  .social-icon {
    min-width: 44px;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .taxonomy-tag {
    min-height: 44px;
    padding-block: var(--space-3);
  }

  .tag {
    min-height: 36px;
    padding-block: var(--space-2);
  }

  .post-nav a {
    min-height: 44px;
    display: flex;
    align-items: flex-start;
    padding-block: var(--space-2);
  }

  .contact-link {
    display: inline-block;
    padding-block: var(--space-2);
  }

  .post-link {
    padding-block: var(--space-2);
  }
}

/* Hover effects only on pointer devices — touch devices have no hover state */
@media (hover: hover) and (pointer: fine) {
  .social-icon:hover {
    transform: translateY(-2px);
  }

  .skill-tag:hover {
    color: var(--color-accent);
    border-color: var(--color-accent);
  }

  .post-item:hover::before {
    background-color: var(--color-accent);
  }
}

/* :active provides immediate visual feedback on touch devices */
@media (hover: none) {
  .social-icon:active {
    color: var(--color-text-secondary);
    transform: scale(0.9);
    transition: transform 80ms;
  }

  .taxonomy-tag:active,
  .tag:active {
    color: var(--color-accent);
    border-color: var(--color-accent);
    opacity: 0.8;
  }

  .post-link:active .post-title {
    color: var(--color-accent);
  }

  .contact-link:active {
    color: var(--color-accent);
    opacity: 0.8;
  }

  .site-nav a:active {
    color: var(--color-text-primary);
    opacity: 0.7;
  }
}