@charset "UTF-8";
:root {
  --ink: #202944;
  --muted: #59657b;
  --blue: #3f52c6;
  --blue-dark: #293a9c;
  --paper: #f5f7fc;
  --white: #fff;
  --line: #dbe1ed;
  --gold: #ffc76c;
  --mint: #d8f1eb;
  --radius: 18px;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
}
a {
  color: inherit;
  text-decoration: none;
}
button,
input,
select {
  font: inherit;
}
button,
a,
input,
select,
summary {
  -webkit-tap-highlight-color: transparent;
}
button,
summary,
select {
  cursor: pointer;
}
button:disabled {
  cursor: default;
  opacity: 0.45;
}
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 4px;
}
button,
input,
select {
  border: 1px solid var(--line);
  border-radius: 9px;
  background: white;
  color: var(--ink);
}
[hidden] {
  display: none !important;
}
.skip {
  position: fixed;
  left: 15px;
  top: -100px;
  z-index: 20;
  padding: 12px;
  background: var(--white);
}
.skip:focus {
  top: 10px;
}
.site-header {
  min-height: 92px;
  display: flex;
  gap: 32px;
  align-items: center;
  justify-content: space-between;
  max-width: 1320px;
  margin: auto;
  padding: 20px 40px;
  border-bottom: 1px solid var(--line);
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 24px;
  font-weight: 850;
  letter-spacing: -1px;
}
.brand small {
  display: block;
  font:
    9px/1.7 Consolas,
    monospace;
  letter-spacing: 2px;
  color: var(--muted);
}
nav {
  display: flex;
  gap: 26px;
  align-items: center;
  font-weight: 650;
  font-size: 14px;
}
nav a:hover,
.text-link:hover {
  color: var(--blue);
  text-decoration: underline;
}
.languages {
  display: flex;
  gap: 12px;
  font-size: 12px;
}
.languages [aria-current] {
  font-weight: 800;
  color: var(--blue);
  border-bottom: 2px solid var(--blue);
}
main {
  max-width: 1240px;
  margin: auto;
  padding: 0 24px 60px;
}
section {
  scroll-margin-top: 24px;
}
h1,
h2,
h3,
p {
  margin-top: 0;
}
h1,
h2,
h3 {
  letter-spacing: -0.04em;
  line-height: 1.2;
}
h1 {
  font-size: clamp(36px, 4.2vw, 60px);
  font-weight: 850;
}
h2 {
  font-size: 29px;
  font-weight: 800;
  margin-bottom: 14px;
}
h3 {
  font-size: 21px;
  margin-bottom: 10px;
}
p {
  line-height: 1.8;
}
small,
.muted {
  color: var(--muted);
  font-size: 13px;
}
.eyebrow,
.category {
  display: block;
  color: var(--blue);
  font:
    700 12px/1.6 "Segoe UI",
    "Microsoft YaHei",
    sans-serif;
  letter-spacing: 0.08em;
  margin-bottom: 14px;
}
.hero {
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  align-items: center;
  gap: 72px;
  padding: 60px 20px 65px;
}
.hero h1 {
  line-height: 1.18;
  margin-bottom: 22px;
}
.hero-copy > p {
  font-size: 17px;
  max-width: 480px;
  color: var(--muted);
}
.actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin: 22px 0 0;
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 11px 18px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--white);
  font-size: 14px;
  font-weight: 650;
  line-height: 1.4;
}
.button:hover {
  border-color: var(--blue);
  color: var(--blue);
}
.button.primary {
  background: var(--blue);
  color: white;
  border-color: var(--blue);
}
.button.primary:hover {
  background: var(--blue-dark);
}
.hero-board {
  background: #dde4fa;
  border: 1px solid #bdc9ed;
  padding: 22px;
  border-radius: 26px;
  max-width: 375px;
  width: 100%;
  justify-self: center;
  box-shadow: 10px 12px 0 #e9edf7;
  transform: rotate(3deg);
  transition: transform 0.2s;
}
.hero-board:hover {
  transform: rotate(0);
}
.tile-board {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.tile {
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  font:
    bold 25px Consolas,
    monospace;
  border-radius: 10px;
  background: #f7f9ff;
  color: #455581;
}
.tile-8,
.tile-16 {
  background: #98a9e7;
  color: #172861;
}
.tile-32 {
  background: #647bd0;
  color: #fff;
}
.tile-64 {
  background: #3f52c6;
  color: #fff;
}
.tile-128 {
  background: var(--gold);
  color: #433817;
}
.board-caption {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 18px;
  font-size: 13px;
}
.board-caption strong {
  font-size: 22px;
}
.section-heading {
  display: flex;
  gap: 22px;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}
.section-heading p {
  color: var(--muted);
  max-width: 720px;
  margin: 0;
}
.pill {
  display: inline-block;
  white-space: nowrap;
  border: 1px solid var(--line);
  border-radius: 30px;
  padding: 6px 12px;
  background: #fff;
  font-size: 12px;
  color: var(--muted);
}
.game-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 20px;
}
.game-grid.featured {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}
.game-card {
  position: relative;
  border: 1px solid var(--line);
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  transition:
    transform 0.15s,
    box-shadow 0.15s;
}
.game-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 7px 22px #2030640c;
}
.game-card > a {
  display: block;
  height: 100%;
}
.game-card img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 12/7;
  object-fit: cover;
}
.card-copy {
  padding: 20px;
}
.card-copy .category {
  font-size: 11px;
  margin-bottom: 6px;
}
.card-copy h3 {
  margin-bottom: 10px;
}
.card-copy p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 18px;
}
.save {
  position: absolute;
  right: 12px;
  top: 12px;
  width: 38px;
  height: 38px;
  border: 0;
  border-radius: 50%;
  font-size: 23px;
  background: #fffffff2;
}
.save[aria-pressed="true"] {
  color: var(--blue);
  background: #fff;
}
.learning-strip {
  margin: 56px 0;
  padding: 32px;
  border: 1px solid #cbd9e6;
  background: #eaf0f6;
  border-radius: 22px;
}
.lesson-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}
.lesson-card {
  position: relative;
  display: block;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: white;
  padding: 26px;
}
.lesson-card:hover {
  border-color: var(--blue);
}
.lesson-card p {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 20px;
}
.lesson-card > span:last-child {
  font-size: 25px;
  color: var(--blue);
}
#catalog {
  margin-top: 52px;
}
.filters {
  display: flex;
  align-items: end;
  gap: 15px;
  flex-wrap: wrap;
  padding: 20px;
  background: #eaf0f6;
  border-radius: 14px;
}
.filters label {
  display: block;
  flex: 1;
  min-width: 145px;
}
.filters label:first-child {
  flex: 2;
  min-width: 240px;
}
.filters label span {
  display: block;
  font-size: 12px;
  margin-bottom: 7px;
  color: var(--muted);
}
input[type="search"],
select {
  width: 100%;
  padding: 12px;
  min-height: 44px;
}
#result-count {
  margin: 20px 0;
}
#empty-results {
  padding: 35px;
  background: white;
  border: 1px dashed var(--line);
  border-radius: 12px;
}
.faq {
  max-width: 840px;
  margin: 65px auto 0;
}
.faq details {
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}
summary {
  font-size: 16px;
  font-weight: 650;
  line-height: 1.5;
}
.faq p {
  margin: 15px 0 0;
  color: var(--muted);
}
footer {
  padding: 35px max(24px, calc((100vw - 1192px) / 2));
  border-top: 1px solid var(--line);
  background: white;
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  align-items: center;
}
footer .brand {
  font-size: 21px;
}
footer p {
  font-size: 12px;
  color: var(--muted);
  margin: 0;
  flex: 1;
  min-width: 220px;
}
footer small {
  width: 100%;
}
.status:empty {
  display: none;
}
.status {
  max-width: 1192px;
  margin: 12px auto;
  padding: 14px 24px;
  background: var(--mint);
  border-radius: 10px;
}
.breadcrumbs {
  display: flex;
  gap: 12px;
  padding: 30px 0;
  color: var(--muted);
  font-size: 13px;
}
.breadcrumbs a {
  text-decoration: underline;
}
.game-heading {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: center;
  margin-bottom: 28px;
}
.game-heading h1 {
  font-size: 42px;
  margin-bottom: 14px;
}
.game-heading p {
  max-width: 750px;
  color: var(--muted);
}
.tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.play-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 24px;
}
.play-area {
  min-width: 0;
}
#game-stage {
  height: 640px;
  background: #e6eaf5;
  border: 1px solid var(--line);
  border-radius: 18px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}
#game-stage iframe {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
  background: #111827;
}
#game-stage:fullscreen {
  height: 100%;
  width: 100%;
  border: 0;
  border-radius: 0;
}
.launch {
  text-align: center;
  padding: 24px;
  max-width: 480px;
}
.launch img {
  width: 220px;
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  margin-bottom: 26px;
}
.launch p {
  color: var(--muted);
  font-size: 14px;
}
.game-toolbar {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin: 14px 0;
}
.game-toolbar a {
  font-size: 13px;
  text-decoration: underline;
  margin-left: auto;
}
.quick-guide {
  align-self: start;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: white;
}
.quick-guide h2 {
  font-size: 18px;
  margin-top: 28px;
}
.quick-guide p {
  font-size: 14px;
  line-height: 1.9;
}
.quick-guide a {
  color: var(--blue);
}
.local-record {
  border-top: 1px solid var(--line);
  margin-top: 25px;
}
.rules {
  margin: 46px 0;
  background: white;
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 30px;
}
.rules-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 26px 40px;
}
.rules h3 {
  font-size: 19px;
}
.rules p {
  font-size: 15px;
  color: var(--muted);
  margin: 0;
}
.related {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}
.text-link {
  display: inline-block;
  margin-top: 24px;
  color: var(--blue);
}
.page-intro {
  padding: 45px 0 30px;
  max-width: 840px;
}
.page-intro p {
  color: var(--muted);
  font-size: 18px;
}
.page-intro h1 {
  font-size: clamp(30px, 4vw, 48px);
}
.lesson-layout {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 50px;
}
.prose h2 {
  font-size: 23px;
  line-height: 1.5;
  margin: 28px 0 13px;
}
.prose p {
  line-height: 1.95;
  color: var(--muted);
}
.prose a:not(.button) {
  color: var(--blue);
  text-decoration: underline;
}
.experiment {
  position: sticky;
  top: 20px;
  align-self: start;
  padding: 28px;
  background: white;
  border: 1px solid var(--line);
  border-radius: 18px;
}
.experiment h2 {
  font-size: 24px;
}
.experiment p {
  font-size: 14px;
}
.experiment label {
  display: block;
}
.experiment select {
  margin-top: 10px;
}
.experiment details {
  border-top: 1px solid var(--line);
  margin-top: 20px;
  padding-top: 18px;
}
.example-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin: 20px 0;
}
.example-row span {
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  background: #dde4fa;
  border-radius: 10px;
  font:
    bold 24px Consolas,
    monospace;
}
.puzzle-diagram {
  width: 204px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 4px;
  margin: 20px auto;
}
.puzzle-diagram span {
  height: 64px;
  display: grid;
  place-items: center;
  background: #e5eaf3;
  font-size: 24px;
  font-weight: bold;
}
.puzzle-diagram .unknown {
  background: var(--gold);
}
.puzzle-diagram .wall {
  background: var(--ink);
  color: var(--ink);
}
fieldset {
  border: 0;
  padding: 0;
  margin: 0 0 18px;
}
legend {
  font-size: 14px;
  line-height: 1.8;
  margin-bottom: 12px;
}
.choice {
  padding: 10px 0;
  font-size: 14px;
}
.choice input {
  margin-right: 8px;
  accent-color: var(--blue);
}
#experiment-result {
  margin: 18px 0 0;
  color: var(--blue);
  font-weight: 600;
}
.information {
  max-width: 790px;
  margin: 50px auto;
}
.information > h1 {
  font-size: 40px;
}
@media (min-width: 1000px) {
  .featured .card-copy p {
    min-height: 50px;
  }
}
@media (max-width: 960px) {
  .site-header {
    padding: 18px 24px;
    gap: 20px;
  }
  .site-header nav {
    gap: 14px;
  }
  .hero {
    gap: 30px;
    padding: 44px 0;
  }
  .game-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .play-layout {
    grid-template-columns: 1fr;
  }
  .quick-guide {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px 25px;
  }
  .quick-guide > * {
    margin: 0 !important;
  }
  .local-record {
    padding-top: 14px;
    grid-column: 1/-1;
  }
  .lesson-layout {
    gap: 25px;
  }
  .learning-strip {
    padding: 24px;
  }
  .lesson-card {
    padding: 20px;
  }
}
@media (max-width: 680px) {
  .site-header {
    flex-wrap: wrap;
    padding: 16px 20px;
    gap: 17px;
  }
  .brand {
    font-size: 22px;
  }
  .site-header nav {
    order: 3;
    width: 100%;
    justify-content: space-between;
    font-size: 13px;
  }
  .languages {
    margin-left: auto;
  }
  main {
    padding: 0 18px 45px;
  }
  .hero {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 36px 0;
  }
  .hero h1 {
    font-size: 40px;
  }
  .hero-copy > p {
    font-size: 15px;
  }
  .hero-board {
    max-width: 275px;
    padding: 16px;
    margin-bottom: 20px;
    transform: rotate(2deg);
  }
  .tile {
    font-size: 20px;
  }
  .hero .actions {
    margin-top: 18px;
  }
  .section-heading {
    align-items: start;
  }
  .section-heading h2,
  h2 {
    font-size: 25px;
  }
  .section-heading p {
    font-size: 14px;
  }
  .game-grid,
  .game-grid.featured,
  .related {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
  }
  .card-copy {
    padding: 14px;
  }
  .card-copy h3 {
    font-size: 18px;
  }
  .card-copy p {
    font-size: 13px;
    line-height: 1.7;
  }
  .card-copy small {
    font-size: 11px;
  }
  .save {
    width: 34px;
    height: 34px;
    right: 8px;
    top: 8px;
  }
  .learning-strip {
    margin: 36px -2px;
    padding: 20px 16px;
  }
  .lesson-grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .lesson-card {
    padding: 20px;
  }
  .lesson-card h3 {
    font-size: 20px;
  }
  .filters {
    padding: 16px;
    gap: 12px;
  }
  .filters label:first-child {
    min-width: 100%;
    flex-basis: 100%;
  }
  .filters label {
    min-width: 120px;
  }
  .filters button {
    width: 100%;
  }
  .game-heading {
    align-items: start;
  }
  .game-heading h1 {
    font-size: 33px;
  }
  .game-heading > button {
    font-size: 12px;
    padding: 8px;
    min-width: 75px;
  }
  .game-heading p {
    font-size: 14px;
  }
  #game-stage {
    height: 650px;
    max-height: 85svh;
    min-height: 470px;
  }
  .quick-guide {
    display: block;
    padding: 20px;
  }
  .quick-guide h2 {
    margin: 20px 0 10px !important;
  }
  .quick-guide p {
    margin-bottom: 14px !important;
  }
  .rules {
    padding: 22px;
    margin: 30px 0;
  }
  .rules .section-heading {
    display: block;
  }
  .rules-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .lesson-layout {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .experiment {
    position: static;
    grid-row: 1;
  }
  .page-intro {
    padding: 25px 0;
  }
  .page-intro p {
    font-size: 16px;
  }
  .information {
    margin: 30px 0;
  }
  .information > h1 {
    font-size: 34px;
  }
  footer {
    padding: 28px 20px;
  }
  footer nav {
    width: 100%;
    gap: 18px;
  }
  .faq {
    margin-top: 40px;
  }
}
@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto !important;
    transition: none !important;
  }
}