/* The web site of BBO. Its look comes from the game: a sky blue that runs to
   navy, white lettering with a navy edge, and buttons like the game's own.
   Nothing is loaded from elsewhere (no web fonts): the site opens as fast in
   mainland China as anywhere. */
:root {
  --sky: #2aa7ff;
  --sky-light: #c9ecff;
  --deep: #0a3c86;
  --navy: #062a63;
  --ink: #12305e;
  --ink-soft: #46608a;
  --gold: #ffd21f;
  --orange: #ff9a00;
  --pink: #ff4f9a;
  --white: #ffffff;
  --paper: #f3faff;
  --line: #cfe3f5;
  --radius: 18px;
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC",
          "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 16px/1.7 var(--font);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--deep); }
h1, h2, h3 { line-height: 1.25; text-wrap: balance; margin: 0; }
.wrap { max-width: 1120px; margin: 0 auto; padding-inline: 20px; }

/* ------------------------------------------------------------ the bar */
.bar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: linear-gradient(var(--deep), var(--navy));
  box-shadow: 0 2px 0 rgba(0, 0, 0, .15);
}
.bar-in {
  max-width: 1120px;
  margin: 0 auto;
  padding: 8px 20px;
  display: flex;
  align-items: center;
  gap: 18px;
}
.brand img { width: 102px; height: auto; }
.menu { display: flex; gap: 4px; margin-left: auto; }
.menu a {
  padding: 6px 12px;
  border-radius: 999px;
  color: var(--white);
  font-weight: 700;
  text-decoration: none;
}
.menu a:hover, .menu a:focus-visible { background: rgba(255, 255, 255, .15); }
.lang {
  border: 2px solid rgba(255, 255, 255, .55);
  border-radius: 999px;
  background: none;
  color: var(--white);
  font: 700 14px/1 var(--font);
  padding: 7px 12px;
  cursor: pointer;
}
.lang:hover { background: rgba(255, 255, 255, .15); }
.menu-toggle { display: none; }

/* ------------------------------------------------------------ buttons */
.btn {
  display: inline-grid;
  place-items: center;
  min-height: 46px;
  padding: 0 26px;
  border: 3px solid var(--navy);
  border-radius: 14px;
  color: var(--white);
  font-weight: 900;
  font-size: 17px;
  text-decoration: none;
  text-shadow: -1px -1px 0 var(--navy), 1px -1px 0 var(--navy), -1px 1px 0 var(--navy), 1px 1px 0 var(--navy);
  box-shadow: 0 4px 0 var(--navy), inset 0 2px 0 rgba(255, 255, 255, .7);
  transition: transform .08s, filter .15s;
  white-space: nowrap;
}
.btn:hover { filter: brightness(1.07) saturate(1.1); }
.btn:active { transform: translateY(3px); box-shadow: 0 1px 0 var(--navy); }
.btn-gold {
  border-color: #7a3c00;
  background: linear-gradient(#fff6b8 0%, #ffe12e 45%, #ffb400 55%, #ff9800 100%);
  text-shadow: -1px -1px 0 #7a3c00, 1px -1px 0 #7a3c00, -1px 1px 0 #7a3c00, 1px 1px 0 #7a3c00;
  box-shadow: 0 4px 0 #5a2c00, inset 0 2px 0 rgba(255, 255, 255, .7);
}
.btn-gold:active { box-shadow: 0 1px 0 #5a2c00; }
.btn-sky { background: linear-gradient(#bff0ff 0%, #5fcbff 45%, #1693e8 55%, #0f7bd6 100%); }
.btn-off {
  background: #b7c6d8;
  border-color: #8a9bb2;
  color: #eef3f8;
  text-shadow: none;
  box-shadow: 0 4px 0 #8a9bb2;
  cursor: default;
}
.btn-big { min-height: 58px; padding: 0 34px; font-size: 21px; border-radius: 16px; }
.btn-small { min-height: 38px; padding: 0 16px; font-size: 15px; border-radius: 12px; }

/* ------------------------------------------------------------ the first view */
.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(ellipse 60% 40% at 15% 20%, rgba(255, 255, 255, .55), transparent 70%),
    radial-gradient(ellipse 50% 35% at 85% 10%, rgba(255, 255, 255, .45), transparent 70%),
    linear-gradient(#7fd3ff 0%, var(--sky) 55%, #1879d8 100%);
  color: var(--white);
}
.hero-in {
  position: relative;
  max-width: 1120px;
  margin: 0 auto;
  padding: 56px 20px 72px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  gap: 40px;
  align-items: center;
}
.eyebrow {
  display: inline-block;
  margin: 0 0 14px;
  padding: 4px 14px;
  border-radius: 999px;
  background: rgba(6, 42, 99, .35);
  font-weight: 700;
  letter-spacing: .08em;
}
.hero h1 {
  font-size: clamp(40px, 6vw, 68px);
  font-weight: 900;
  letter-spacing: .02em;
  text-shadow: -3px -3px 0 var(--navy), 3px -3px 0 var(--navy), -3px 3px 0 var(--navy), 3px 3px 0 var(--navy),
               0 6px 0 var(--navy);
}
html:lang(zh-Hans) .hero h1 span { white-space: nowrap; }   /* the Chinese name breaks only before BBO */
.title-latin { color: var(--gold); }
.lead { margin: 18px 0 26px; font-size: 18px; max-width: 32em; text-shadow: 0 1px 2px rgba(6, 42, 99, .5); }
.actions { display: flex; flex-wrap: wrap; gap: 14px; }
.chips { display: flex; flex-wrap: wrap; gap: 10px; margin: 24px 0 0; padding: 0; list-style: none; }
.chips li {
  padding: 4px 14px;
  border: 2px solid rgba(255, 255, 255, .7);
  border-radius: 999px;
  font-weight: 700;
  font-size: 15px;
}
.hero-art {
  margin: 0;
  border: 6px solid var(--white);
  border-radius: 28px;
  overflow: hidden;
  box-shadow: 0 10px 0 var(--navy), 0 18px 40px rgba(6, 42, 99, .35);
  transform: rotate(1.5deg);
}
.bubbles i {
  position: absolute;
  bottom: -60px;
  width: 40px;
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, .95), rgba(255, 255, 255, .25) 35%,
                              rgba(120, 210, 255, .25) 70%, rgba(255, 255, 255, .6) 100%);
  animation: rise 14s linear infinite;
}
.bubbles i:nth-child(1) { left: 6%; animation-delay: -2s; }
.bubbles i:nth-child(2) { left: 18%; width: 24px; animation-duration: 11s; animation-delay: -7s; }
.bubbles i:nth-child(3) { left: 33%; width: 56px; animation-duration: 18s; animation-delay: -4s; }
.bubbles i:nth-child(4) { left: 48%; width: 30px; animation-duration: 12s; animation-delay: -9s; }
.bubbles i:nth-child(5) { left: 64%; width: 20px; animation-duration: 10s; animation-delay: -1s; }
.bubbles i:nth-child(6) { left: 79%; width: 46px; animation-duration: 16s; animation-delay: -11s; }
.bubbles i:nth-child(7) { left: 92%; width: 28px; animation-duration: 13s; animation-delay: -5s; }
@keyframes rise {
  to { transform: translateY(-760px) translateX(30px); opacity: .2; }
}
@media (prefers-reduced-motion: reduce) {
  .bubbles { display: none; }
  html { scroll-behavior: auto; }
}

/* ------------------------------------------------------------ bands */
.band { padding: 64px 0; }
.band-sky { background: linear-gradient(#e3f5ff, #f3faff); }
.band-deep { background: linear-gradient(var(--deep), var(--navy)); color: var(--white); }
.band h2 {
  font-size: clamp(28px, 3.6vw, 38px);
  font-weight: 900;
  margin-bottom: 28px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.band h2::before {
  content: "";
  width: 22px;
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(circle at 32% 30%, #fff 0 18%, var(--sky) 45%, var(--deep) 100%);
  flex: none;
}
.band-deep h2::before { background: radial-gradient(circle at 32% 30%, #fff 0 18%, var(--gold) 45%, var(--orange)); }
.section-lead { margin: -14px 0 26px; color: var(--ink-soft); max-width: 40em; }

/* news */
.news { margin: 0; padding: 0; list-style: none; display: grid; gap: 12px; }
.news li {
  display: grid;
  grid-template-columns: 112px auto 1fr;
  align-items: baseline;
  gap: 4px 14px;
  padding: 16px 20px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 14px;
}
.news time { color: var(--ink-soft); font-variant-numeric: tabular-nums; }
.news .kind {
  padding: 1px 10px;
  border-radius: 999px;
  background: var(--sky-light);
  color: var(--deep);
  font-size: 13px;
  font-weight: 700;
  justify-self: start;
}
.news .kind-update { background: #fff1b8; color: #7a4a00; }
.news .kind-event { background: #ffd9ea; color: #a01a5b; }
.news strong { font-size: 17px; }
.news p { grid-column: 3; margin: 2px 0 0; color: var(--ink-soft); }

.news-tabs { display: flex; flex-wrap: wrap; gap: 8px; margin: -10px 0 18px; }
.news-tabs button {
  padding: 6px 16px;
  border: 2px solid var(--line);
  border-radius: 999px;
  background: var(--white);
  color: var(--ink-soft);
  font: 700 15px var(--font);
  cursor: pointer;
}
.news-tabs button[aria-selected="true"] { border-color: var(--deep); background: var(--deep); color: var(--white); }
.news .kind-guide { background: #dff7d8; color: #24661b; }
.news details { grid-column: 3; }
.news summary {
  font-size: 17px;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
}
.news summary::-webkit-details-marker { display: none; }
.news summary::after { content: " ＋"; color: var(--sky); font-weight: 900; }
.news details[open] summary::after { content: " －"; }
.news details p { color: var(--ink); margin: 8px 0 0; }
.news li.has-more > p { grid-row: 2; }
.news details[open] ~ p { display: none; }
.more {
  display: block;
  margin: 18px auto 0;
  padding: 8px 26px;
  border: 2px solid var(--deep);
  border-radius: 999px;
  background: var(--white);
  color: var(--deep);
  font: 700 15px var(--font);
  cursor: pointer;
}
.more:hover { background: var(--deep); color: var(--white); }

/* features */
.features { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 20px; }
.feature {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.feature img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.feature h3 { font-size: 19px; font-weight: 900; margin: 16px 18px 6px; }
.feature p { margin: 0 18px 20px; color: var(--ink-soft); font-size: 15px; }

/* modes */
.modes { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 44px; align-items: center; }
.modes-art {
  margin: 0;
  border-radius: var(--radius);
  overflow: hidden;
  border: 4px solid var(--white);
  box-shadow: 0 8px 0 var(--deep);
}
.mode-list { margin: 0; display: grid; gap: 6px; }
.mode-list dt { font-weight: 900; font-size: 18px; color: var(--deep); margin-top: 12px; }
.mode-list dt:first-child { margin-top: 0; }
.mode-list dd { margin: 0; color: var(--ink-soft); }

/* gallery */
.gallery { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.gallery button {
  padding: 0;
  border: 3px solid rgba(255, 255, 255, .85);
  border-radius: 14px;
  overflow: hidden;
  background: none;
  cursor: zoom-in;
  transition: transform .15s;
}
.gallery button:hover, .gallery button:focus-visible { transform: translateY(-3px); outline: 3px solid var(--gold); }
.gallery img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.viewer {
  padding: 0;
  border: 4px solid var(--white);
  border-radius: 16px;
  background: var(--navy);
  max-width: min(94vw, 1000px);
}
.viewer::backdrop { background: rgba(3, 18, 44, .8); }
.viewer img { width: 100%; image-rendering: auto; }
.viewer-close {
  position: absolute;
  top: 8px;
  right: 8px;
  border: 0;
  border-radius: 999px;
  padding: 6px 14px;
  background: rgba(6, 42, 99, .85);
  color: var(--white);
  font: 700 14px var(--font);
  cursor: pointer;
}

/* characters */
.chars { margin: 0; padding: 0; list-style: none; display: grid; grid-template-columns: repeat(8, minmax(0, 1fr)); gap: 12px; }
.chars li {
  border-radius: 14px;
  overflow: hidden;
  border: 3px solid var(--white);
  box-shadow: 0 4px 0 var(--line);
  transition: transform .15s;
}
.chars li:hover { transform: translateY(-6px) rotate(-2deg); }
.chars img { width: 100%; image-rendering: pixelated; }

/* guide */
.steps { margin: 0 0 40px; padding: 0; list-style: none; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; counter-reset: step; }
.steps li {
  position: relative;
  padding: 26px 22px 22px 22px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  counter-increment: step;
}
.steps li::before {
  content: counter(step);
  position: absolute;
  top: -18px;
  left: 18px;
  width: 38px;
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: linear-gradient(#fff6b8, #ffb400);
  border: 3px solid #7a3c00;
  color: var(--white);
  font-weight: 900;
  text-shadow: -1px -1px 0 #7a3c00, 1px 1px 0 #7a3c00, 1px -1px 0 #7a3c00, -1px 1px 0 #7a3c00;
}
.steps h3 { font-size: 19px; font-weight: 900; margin-bottom: 6px; }
.steps p { margin: 0; color: var(--ink-soft); }
.keys-title { font-size: 21px; font-weight: 900; margin-bottom: 12px; }
.keys-wrap { overflow-x: auto; }
.keys { border-collapse: collapse; background: var(--white); border-radius: 14px; overflow: hidden; border: 1px solid var(--line); min-width: 320px; }
.keys td { padding: 10px 18px; border-top: 1px solid var(--line); }
.keys tr:first-child td { border-top: 0; }
.keys td:first-child { white-space: nowrap; background: #f6fbff; }
kbd {
  display: inline-block;
  min-width: 30px;
  padding: 2px 8px;
  border: 2px solid var(--deep);
  border-bottom-width: 4px;
  border-radius: 8px;
  background: var(--white);
  font: 700 14px/1.4 var(--font);
  text-align: center;
}

/* download */
.downloads { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.downloads-one { grid-template-columns: minmax(0, 640px); }
.card {
  position: relative;
  display: grid;
  gap: 10px;
  align-content: start;
  justify-items: start;
  padding: 26px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.card-main { border: 3px solid var(--gold); }
.card h3 { font-size: 22px; font-weight: 900; }
.card p { margin: 0 0 8px; color: var(--ink-soft); }
.tag {
  position: absolute;
  top: -14px;
  right: 20px;
  padding: 2px 12px;
  border-radius: 999px;
  background: var(--pink);
  color: var(--white);
  font-weight: 900;
  font-size: 14px;
}

/* recharge */
.recharge { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); gap: 44px; align-items: center; }
.pay-steps { margin: 0 0 14px; padding-left: 1.3em; display: grid; gap: 6px; }
.note { color: var(--ink-soft); margin: 0 0 20px; }
.prices {
  width: 100%;
  border-collapse: collapse;
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 6px 0 var(--line);
  font-variant-numeric: tabular-nums;
}
.prices th { background: var(--deep); color: var(--white); padding: 12px 18px; text-align: left; }
.prices td { padding: 14px 18px; border-top: 1px solid var(--line); font-weight: 700; }
.prices td:first-child { color: #c25e00; font-size: 22px; font-weight: 900; width: 34%; }

/* faq */
.faq details {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 14px;
  margin-bottom: 10px;
  padding: 0 20px;
}
.faq summary { padding: 16px 0; font-weight: 700; cursor: pointer; list-style-position: inside; }
.faq details p { margin: 0 0 16px; color: var(--ink-soft); }

/* footer */
.foot { background: var(--navy); color: #b8cbe6; padding: 40px 0; text-align: center; font-size: 14px; }
.foot-logo { margin: 0 auto 14px; width: 102px; }
.health { margin: 0 0 10px; line-height: 1.9; }
.copy { margin: 0; }

/* ------------------------------------------------------------ narrower screens */
@media (max-width: 960px) {
  .features { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .chars { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .menu a { padding: 6px 8px; }
}
@media (max-width: 820px) {
  .menu-toggle {
    display: block;
    margin-left: auto;
    border: 2px solid rgba(255, 255, 255, .55);
    border-radius: 10px;
    background: none;
    color: var(--white);
    font: 700 14px var(--font);
    padding: 6px 12px;
  }
  .menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    padding: 10px 20px 16px;
    background: var(--navy);
  }
  .menu.open { display: flex; }
  .play-link { display: none; }
  .hero-in, .modes, .recharge { grid-template-columns: minmax(0, 1fr); }
  .hero-in { padding-top: 36px; gap: 28px; }
  .hero-art { transform: none; }
  .steps, .downloads { grid-template-columns: minmax(0, 1fr); gap: 30px; }
  .gallery { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 560px) {
  .features { grid-template-columns: minmax(0, 1fr); }
  .news li { grid-template-columns: auto 1fr; }
  .news strong, .news p, .news details { grid-column: 1 / -1; }
  .news li.has-more > p { grid-row: auto; }
  .btn-big { width: 100%; }
  .actions { display: grid; }
  .band { padding: 48px 0; }
}