/* ============================================================
   Mobile / tablet layer (≤ 1099px)

   The desktop hover-sidebar (header.css, ≥1099px) collapses here
   into a sticky frosted top bar. Tapping the toggle adds
   `header.menu-open`, expanding <header> into a full-screen
   overlay that reveals the editorial nav + footer. Built on the
   tokens in base/variables.css. The 1099px breakpoint is mirrored
   in header.css and js/modules/navigation.js — keep them in sync.
   ============================================================ */
@media (max-width: 1099px) {
  /* ---- Sticky top bar (collapsed header) ---- */
  header {
    /* border-box so width:100% + horizontal padding stays within the
       viewport. Without it the bar (and the .menu-open overlay, which
       inherits width:100%) overflow by 2×--space-5 = 48px: the toggle
       falls off the right edge and the language switch gets clipped. */
    box-sizing: border-box;
    position: sticky;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--bar-h);
    padding: 0 var(--space-5);
    /* block (not flex): the collapsed bar must NOT lay out nav/footer in a
       row — even hidden they'd take flex width, overflow the viewport and
       push the toggle off-screen. They flow below the logo, clipped by the
       fixed height + overflow:hidden, and only show once .menu-open lifts
       the clip. */
    display: block;
    background: var(--frost-bg);
    /* stylelint-disable-next-line property-no-vendor-prefix -- iOS < 18 needs the prefix for the frosted bar */
    -webkit-backdrop-filter: var(--frost-filter);
    backdrop-filter: var(--frost-filter);
    border-bottom: 1px solid var(--line);
    overflow: hidden; /* clip nav/footer while collapsed */
    transform: none; /* cancel any desktop translateX */
    z-index: 9999;
  }

  /* Logo → compact wordmark inside the bar */
  header .logo {
    margin: 0;
    float: none;
    display: flex;
    align-items: center;
    height: var(--bar-h);
  }
  header .logo a,
  header .logo a:active,
  header .logo a:visited {
    font-family: var(--font-sans);
    text-transform: uppercase;
    text-decoration: none;
    color: var(--ink);
    font-size: 15px;
    letter-spacing: 0.18em;
    font-weight: 500;
  }
  header .logo a:hover {
    color: var(--muted);
  }
  /* subtitle/description belong to the desktop sidebar only */
  header .logo .subtitle,
  header .logo .description {
    display: none;
  }

  /* ---- Hamburger toggle (top-right of the bar) ---- */
  #menu_icon {
    display: flex;
    align-items: center;
    justify-content: center;
    position: absolute;
    top: 0;
    right: calc(var(--space-5) - 11px);
    width: var(--tap);
    height: var(--bar-h);
    margin: 0;
    padding: 0;
    border: 0;
    background: transparent;
    cursor: pointer;
    z-index: 2;
  }
  .menu-toggle__bars {
    position: relative;
    width: 22px;
    height: 14px;
  }
  .menu-toggle__bars::before,
  .menu-toggle__bars::after {
    content: '';
    position: absolute;
    left: 0;
    width: 22px;
    height: 2px;
    background: var(--ink);
    border-radius: 2px;
    transition:
      transform 0.28s ease,
      top 0.28s ease,
      bottom 0.28s ease;
  }
  .menu-toggle__bars::before {
    top: 0;
  }
  .menu-toggle__bars::after {
    bottom: 0;
  }

  /* ---- Expanded overlay (header.menu-open) ---- */
  header.menu-open {
    position: fixed;
    inset: 0;
    height: 100dvh;
    display: block;
    padding: 0 var(--space-5) var(--space-5);
    overflow-y: auto;
    background: var(--surface);
    /* stylelint-disable-next-line property-no-vendor-prefix -- pair with the prefixed bar rule */
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }
  header.menu-open .logo {
    height: var(--bar-h);
  }
  /* bars morph into an X */
  header.menu-open .menu-toggle__bars::before {
    top: 6px;
    transform: rotate(45deg);
  }
  header.menu-open .menu-toggle__bars::after {
    bottom: 6px;
    transform: rotate(-45deg);
  }

  /* nav + footer hidden (and unfocusable) until the overlay opens */
  header nav,
  header .footer {
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease;
  }
  header.menu-open nav,
  header.menu-open .footer {
    opacity: 1;
    visibility: visible;
  }

  /* ---- Editorial navigation ---- */
  header nav {
    width: 100%;
    margin-top: var(--space-4);
  }
  header nav ul {
    display: block;
    counter-reset: nav;
    margin: 0;
    list-style: none;
  }
  header nav ul li {
    display: block;
    margin: 0;
  }
  header nav ul li a {
    display: flex;
    align-items: baseline;
    gap: var(--space-3);
    width: 100%;
    padding: 16px 2px;
    border-top: none;
    border-bottom: 1px solid var(--line);
    color: var(--ink-strong);
    font-family: var(--font-sans);
    font-size: 27px;
    font-weight: 500;
    letter-spacing: 0.01em;
    text-align: left;
    text-decoration: none;
    background: transparent;
    /* stagger-in starting state */
    opacity: 0;
    transform: translateY(12px);
  }
  header nav ul li a::before {
    counter-increment: nav;
    content: counter(nav, decimal-leading-zero);
    align-self: center;
    min-width: 22px;
    color: var(--faint);
    font-size: 12px;
    font-weight: 500;
    letter-spacing: 0;
  }
  /* current page: tint the numeral */
  header nav ul li a.selected {
    color: var(--ink-strong);
  }
  header nav ul li a.selected::before {
    color: var(--accent);
  }

  /* stagger the items in once the overlay is open */
  header.menu-open nav ul li a {
    opacity: 1;
    transform: none;
    transition:
      opacity 0.4s ease,
      transform 0.4s ease;
  }
  header.menu-open nav ul li:nth-child(1) a {
    transition-delay: 0.08s;
  }
  header.menu-open nav ul li:nth-child(2) a {
    transition-delay: 0.16s;
  }
  header.menu-open nav ul li:nth-child(3) a {
    transition-delay: 0.24s;
  }
  header.menu-open nav ul li:nth-child(4) a {
    transition-delay: 0.32s;
  }

  /* ---- Footer inside the overlay ---- */
  header .footer {
    display: block;
    position: static;
    margin-top: var(--space-6);
  }

  /* Language: labelled row + EN · 中文 segmented control (mobile only) */
  .lang-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 0;
    margin-bottom: var(--space-5);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
  }
  .lang-row__label {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    color: var(--muted);
    font-family: var(--font-sans);
    font-size: 14px;
  }
  .lang-row__icon {
    width: 18px;
    height: 18px;
    background: currentColor;
    mask-image: url('../img/social/icon-language.svg');
    mask-repeat: no-repeat;
    mask-position: center;
    mask-size: contain;
  }
  .lang-switch {
    display: inline-flex;
    overflow: hidden;
    border: 1px solid var(--line-2);
    border-radius: var(--radius);
  }
  .lang-switch__opt {
    appearance: none;
    margin: 0;
    border: 0;
    padding: 9px 18px;
    background: var(--surface);
    color: var(--muted);
    font-family: var(--font-sans);
    font-size: 14px;
    letter-spacing: 0.02em;
    cursor: pointer;
  }
  .lang-switch__opt[aria-pressed='true'] {
    background: var(--ink);
    color: #fff;
  }

  /* Social icons → flex row (cancel the desktop float) */
  header ul.social {
    display: flex;
    flex-wrap: wrap;
    gap: 11px;
    margin: 0 0 var(--space-5);
    padding: 0;
  }
  header ul.social li {
    display: block;
    float: none;
    margin: 0;
  }
  header ul.social li a {
    width: var(--tap);
    height: var(--tap);
    border-radius: 13px;
    border-color: var(--line-2);
  }
  /* the globe toggle is replaced by the .lang-row control on mobile */
  header ul.social li.social-lang {
    display: none;
  }

  /* Copyright / credits */
  header .rights p {
    margin: 0;
    color: var(--muted);
    font-family: var(--font-sans);
    font-size: 11px;
    letter-spacing: 0.5px;
    line-height: 1.9;
  }
  header .rights a {
    color: var(--ink);
    font-weight: 500;
    text-decoration: none;
  }

  /* ---- Main content: drop the desktop sidebar offset ---- */
  .main,
  header:not(.show_menu) ~ .main {
    width: 100%;
    padding-left: 0;
    position: relative;
  }

  /* ---- Portfolio grid: gapless photo tiles with captions ---- */
  .main .work {
    width: calc(100% / 3); /* 3 columns on tablet */
    margin: 0;
  }
  /* Title scrim — always visible on touch (hover never fires) */
  .main .work .caption {
    top: auto;
    bottom: 0;
    height: auto;
    opacity: 1;
    background: linear-gradient(transparent, rgb(0 0 0 / 0.55));
  }
  .work .caption .work_title {
    box-sizing: border-box;
    position: static;
    top: auto;
    margin-top: 0;
    padding: 36px 12px 12px;
    text-align: left;
  }
  .main .work .caption h2 {
    max-width: 100%;
    padding: 0;
    border: 0;
    color: #fff;
    font-size: 15px;
    letter-spacing: 0.03em;
  }
}

@media (max-width: 768px) {
  .main .work {
    width: 50%; /* 2 columns */
  }

  /* ---- Archive page: scale down + reclaim horizontal room ----
     The desktop archive uses a 120px gutter for the absolute-positioned date
     plus a 65px list indent — on a phone that squeezes titles into a sliver.
     Trim the card padding, drop the indent, narrow the gutter, shrink type. */
  .content.archives {
    margin-top: 24px;
    padding: 36px 18px;
  }
  #tag-graph-section {
    margin-bottom: 24px;
    padding-bottom: 16px;
  }
  .content .archive-year {
    margin-bottom: 28px;
  }
  .content .archive-year .year-title {
    font-size: 21px;
    margin-bottom: 14px;
    padding-bottom: 8px;
  }
  .content ul.archive-list {
    margin-left: 0;
    padding-left: 0;
  }
  .content ul.archive-list li.archive-item {
    margin: 12px 0;
    padding-left: 92px;
  }
  .content ul.archive-list li.archive-item .archive-date {
    font-size: 13px;
  }
  .content ul.archive-list li a {
    font-size: 15px;
  }
}

/* Mobile long-form reading: one clean measure with no heading-based indent. */
@media (max-width: 768px) {
  .content:not(.archives) {
    padding: 44px 18px 60px;
    font-size: 16px;
    line-height: 1.75;
  }

  .content:not(.archives) p,
  .content:not(.archives) ol,
  .content:not(.archives) ul {
    font-size: 16px;
    line-height: 1.75;
  }

  .content:not(.archives) h1 {
    margin-bottom: 24px;
    font-size: 28px;
  }

  .content:not(.archives) h2 {
    margin-top: 46px;
    margin-bottom: 18px;
    padding-bottom: 8px;
    font-size: 24px;
  }

  .content:not(.archives) h3 {
    margin-top: 36px;
    margin-bottom: 15px;
    font-size: 20px;
  }

  .content:not(.archives) h4 {
    margin-top: 30px;
    font-size: 18px;
  }

  .content:not(.archives) h5,
  .content:not(.archives) h6 {
    font-size: 16px;
  }

  .content:not(.archives) h1,
  .content:not(.archives) h2,
  .content:not(.archives) h3,
  .content:not(.archives) h4,
  .content:not(.archives) h5,
  .content:not(.archives) h6 {
    padding-left: 22px;
  }

  .content:not(.archives) blockquote {
    padding: 12px 14px;
  }

  .content:not(.archives) > .media-layout {
    margin-top: 20px;
    margin-bottom: 20px;
  }

  .media-layout--grid,
  .media-layout--quad,
  .media-layout--pair {
    grid-template-columns: minmax(0, 1fr);
  }

  .media-layout--left,
  .media-layout--right {
    justify-content: center;
  }
}

@media (max-width: 550px) {
  .main .work {
    width: 100%; /* single column */
  }
}

/* Honour reduced-motion: no morph, no stagger */
@media (max-width: 1099px) and (prefers-reduced-motion: reduce) {
  .menu-toggle__bars::before,
  .menu-toggle__bars::after,
  header.menu-open nav ul li a {
    transition: none !important;
  }
  header nav ul li a {
    opacity: 1;
    transform: none;
  }
}