/* Shared theme roles; components consume tokens rather than choose palettes. */
:root {
  --serif: 'Noto Serif SC', 'Songti SC', Georgia, serif;
  --sans: Inter, 'PingFang SC', 'Microsoft YaHei', sans-serif;
}
html {
  background: var(--paper);
}
body {
  background:
    radial-gradient(
      ellipse at 90% 0,
      color-mix(in srgb, var(--season-glow) 65%, transparent),
      transparent 42%
    ),
    var(--paper);
  color: var(--ink);
}
body :is(input, textarea, select) {
  accent-color: var(--accent);
  caret-color: var(--ink);
}
::selection {
  background: var(--panel);
  color: var(--ink);
}
.site-header {
  background: color-mix(in srgb, var(--paper) 94%, transparent);
}
.site-header nav {
  margin-left: auto;
}
.site-header nav a:hover {
  color: var(--accent);
}
.site-header nav a {
  color: var(--ink);
  font: 600 13px/1.75 var(--sans);
}
/* Public navigation remains readable before and after the shared theme mounts. */
.site-header:has(.site-nav) {
  position: relative;
  z-index: 30;
}
.site-header .site-nav {
  position: relative;
  flex: 0 1 auto;
}
.site-nav .site-nav-links {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
}
.site-nav .site-nav-links > a,
.site-nav summary {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
}
.site-nav summary {
  cursor: pointer;
  list-style: none;
  color: var(--ink);
  font: 600 13px/1.75 var(--sans);
}
.site-nav summary::-webkit-details-marker {
  display: none;
}
.site-nav summary::after {
  content: '⌄';
  margin-left: 6px;
  color: var(--muted);
}
.site-nav-more {
  position: relative;
}
.site-nav-more[open] > summary::after {
  transform: rotate(180deg);
}
.site-nav-more.active > summary {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 7px;
}
.site-nav-extra {
  position: absolute;
  right: 0;
  top: 100%;
  min-width: 132px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  box-shadow: 0 12px 30px #10202c20;
}
.site-header .site-nav-extra a {
  display: flex;
  min-height: 44px;
  padding: 8px 12px;
  white-space: nowrap;
  border-radius: 6px;
}
.site-nav-extra a:hover {
  background: var(--panel);
}
.site-nav-toggle {
  display: none;
  min-height: 44px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink);
  font: 600 13px/1.5 var(--sans);
  cursor: pointer;
}
.site-nav :focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}
@media (max-width: 800px) {
  .site-header .site-nav.nav-ready {
    order: 0;
    flex-basis: auto;
    margin-left: auto;
  }
  .site-nav.nav-ready .site-nav-toggle {
    display: inline-flex;
    align-items: center;
  }
  .site-nav.nav-ready .site-nav-links {
    display: none;
    position: absolute;
    right: 0;
    top: calc(100% + 8px);
    width: min(280px, calc(100vw - 32px));
    max-height: calc(100dvh - 120px);
    overflow-y: auto;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 12px;
    background: var(--surface);
    box-shadow: 0 12px 30px #10202c20;
  }
  .site-nav.nav-ready.is-open .site-nav-links {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .site-nav .site-nav-links > a,
  .site-nav summary {
    padding: 8px 12px;
  }
  .site-nav-extra {
    position: static;
    padding: 0 0 0 12px;
    border: 0;
    box-shadow: none;
    background: transparent;
  }
}
.theme-entry {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  flex: 0 0 auto;
  min-height: 38px;
  padding: 7px 11px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--surface);
  color: var(--accent);
  font: 12px/1.5 var(--sans, system-ui);
  letter-spacing: 0.02em;
  cursor: pointer;
}
.theme-entry:hover {
  background: var(--panel);
  color: var(--ink);
  border-color: var(--accent);
}
.theme-entry svg {
  width: 19px;
  height: 19px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.3;
  stroke-linejoin: round;
}
.theme-admin-bar {
  display: flex;
  justify-content: flex-end;
  max-width: 1600px;
  margin: auto;
  padding: 12px 28px 0;
}
.theme-panel {
  box-sizing: border-box;
  width: min(420px, calc(100% - 28px));
  max-height: calc(100dvh - 32px);
  overflow-y: auto;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
  color: var(--ink);
  box-shadow: 0 24px 80px #10202c38;
  font: 14px/1.65 var(--sans, system-ui);
}
.theme-panel::backdrop {
  background: #10202c70;
  backdrop-filter: blur(4px);
}
.theme-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.theme-heading .eyebrow {
  margin: 0 0 4px;
  color: var(--accent);
  font-size: 10px;
  letter-spacing: 0.15em;
}
.theme-heading h2 {
  margin: 0;
  font: 600 26px/1.5 var(--serif, Georgia);
}
.theme-panel button {
  min-height: 44px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
  padding: 8px 12px;
  font: inherit;
  cursor: pointer;
  border-radius: 8px;
}
.theme-panel button:hover {
  background: var(--panel);
}
.theme-panel .theme-close {
  width: 44px;
  font-size: 22px;
}
.theme-panel label {
  display: block;
  margin-top: 16px;
  margin-bottom: 6px;
}
.theme-panel select {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 10px;
  color: var(--ink);
  background: var(--paper);
  font: inherit;
}
.theme-current {
  padding: 10px 12px;
  border-left: 2px solid var(--accent);
  background: var(--panel);
  color: var(--ink);
  font-size: 12px;
}
.theme-panel .theme-motion {
  display: flex;
  align-items: center;
  gap: 9px;
}
.theme-motion input {
  width: 18px;
  height: 18px;
  margin: 0;
}
.theme-hint {
  color: var(--muted);
  font-size: 12px;
  margin: 14px 0 18px;
}
.theme-panel :focus-visible,
.theme-entry:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}
/* Game colours retain readable numbers and unambiguous light/dark targets. */
.tile {
  color: var(--tile-light-ink);
}
.tile:is(
  [data-value='32'],
  [data-value='64'],
  [data-value='128'],
  [data-value='256'],
  [data-value='512'],
  [data-value='1024'],
  [data-value='2048']
) {
  color: var(--tile-strong-ink);
}
.tile[data-value='2'] {
  color: var(--tile-text-2);
}
.tile[data-value='4'] {
  color: var(--tile-text-4);
}
.tile[data-value='8'] {
  color: var(--tile-text-8);
}
.tile[data-value='16'] {
  color: var(--tile-text-16);
}
.tile[data-value='32'] {
  color: var(--tile-text-32);
}
.tile[data-value='64'] {
  color: var(--tile-text-64);
}
.tile:is([data-value='128'], [data-value='256']) {
  color: var(--tile-text-128);
}
.tile-button {
  background: var(--game-light);
}
.tile-button.dark {
  background: var(--tile-dark);
}
.tile-button.dark:hover {
  background: var(--tile-dark);
  box-shadow: inset 0 0 0 3px var(--accent);
}
.tile-button.hit {
  background: var(--panel);
}
.mine-cell {
  background: color-mix(in srgb, var(--accent) 22%, var(--panel));
  color: var(--ink);
}
.mine-cell.revealed {
  background: var(--surface);
}
.mine-cell.flagged {
  background: var(--panel);
  color: var(--accent);
}
.mine-cell.mine {
  background: var(--danger-fill);
  color: var(--on-danger);
}
.mine-cell[data-nearby='1'] {
  color: var(--accent);
}
.mine-cell[data-nearby='2'] {
  color: var(--ink);
}
.mine-cell[data-nearby='3'] {
  color: var(--danger);
}
.mine-cell[data-nearby='4'] {
  color: var(--muted);
}
.white-tiles-tool-icon i {
  background: var(--surface);
  border-color: var(--accent);
}
.white-tiles-tool-icon i:nth-child(3) {
  background: var(--tile-dark);
  border-color: var(--tile-dark);
}
.footer-social-link svg {
  color: var(--accent);
}
.music-toggle {
  color: var(--surface);
}
body[data-season] .music-toggle {
  background: var(--ink);
}
.landscape-water {
  filter: var(--scene-filter, none);
}
.landscape-image {
  filter: var(--scene-filter, none);
}
html[data-period='dawn'] {
  --scene-filter: sepia(0.1) saturate(0.85) brightness(0.99);
}
html[data-period='day'] {
  --scene-filter: saturate(0.9);
}
html[data-period='dusk'] {
  --scene-filter: sepia(0.23) saturate(0.85) brightness(0.86);
}
html[data-period='night'] {
  --scene-filter: saturate(0.65) brightness(0.42);
}
html[data-period='night'] .landscape-mist {
  opacity: 0.12;
}
html[data-period='night'] .weather-light {
  opacity: 0.45;
}
html[data-effects='false'] .landscape-mist {
  animation: none;
}
@media (max-width: 800px) {
  .site-header {
    gap: 4px 12px;
  }
  .site-header .brand {
    margin-right: auto;
  }
  .site-header nav {
    order: 3;
    flex-basis: 100%;
    margin: 0;
    gap: 20px;
  }
  .theme-entry {
    min-height: 36px;
    padding: 5px 10px;
  }
  .theme-panel {
    padding: 20px;
  }
  .theme-admin-bar {
    padding: 10px 20px 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .landscape-image,
  .theme-entry {
    transition: none;
  }
}