/* bntk.fun, in the game's Mực tàu colours (client/src/ui/themes.ts) and its fonts. Radius 0, as in the game. */
:root {
  --ground: #111315;
  --line: #6a7078;
  --text: #e6e8ea;
  --text-strong: #ffffff;
  --text-dim: #c9cdd3;
  --accent: #e8e2d0;
  --accent-ink: #111315;
  --gold: #d9b45f;
  --wrap: 1040px;
}
* { box-sizing: border-box; }
html { background: var(--ground); scrollbar-gutter: stable; }
body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  color: var(--text);
  font: 16px/1.65 "Be Vietnam Pro", system-ui, sans-serif;
  text-shadow: 0 1px 4px rgb(0 0 0 / 0.9);
}
a { color: var(--text-strong); }
.bg { position: fixed; inset: 0; z-index: -1; overflow: hidden; }
.bg video, .bg img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 30%; }
.bg::after {
  content: "";
  position: absolute;
  inset: 0;
  /* No sheets over the video (release.md §12): a dark band behind the text column, the art left lighter at the sides. */
  background:
    linear-gradient(180deg, rgb(17 19 21 / 0.3), transparent 25%, transparent 70%, rgb(17 19 21 / 0.5)),
    linear-gradient(90deg, rgb(17 19 21 / 0.45), rgb(17 19 21 / 0.82) 25%, rgb(17 19 21 / 0.82) 75%, rgb(17 19 21 / 0.45));
}
header, main, footer { width: 100%; max-width: var(--wrap); margin: 0 auto; padding-left: 24px; padding-right: 24px; }

/* Header: icon and name left, links and language right. */
header { display: flex; align-items: center; justify-content: space-between; gap: 20px; height: 72px; }
.brand { display: flex; align-items: center; gap: 10px; font: 600 20px/1.2 "Noto Serif", Georgia, serif; color: var(--text-strong); text-decoration: none; }
.brand img { display: block; }
nav { display: flex; gap: 24px; flex-wrap: wrap; align-items: center; }
nav a { color: var(--text-dim); text-decoration: none; font-size: 15px; }
nav a:hover, nav a[aria-current="page"] { color: var(--text-strong); }
nav a[aria-current="page"] { box-shadow: 0 2px 0 var(--gold); }
.lang { display: flex; gap: 5px; }
.lang button {
  height: 32px; min-width: 40px; padding: 0 10px;
  font: 600 13px "Be Vietnam Pro", sans-serif;
  color: var(--text-dim); background: rgb(17 19 21 / 0.35); border: 0; border-radius: 0; cursor: pointer;
  box-shadow: inset 0 0 0 1px var(--line);
}
.lang button[aria-pressed="true"] { color: var(--accent-ink); background: var(--accent); box-shadow: none; }

main { flex: 1; padding-top: 48px; padding-bottom: 80px; }
h1, h2, h3 { font-family: "Noto Serif", Georgia, serif; font-weight: 600; color: var(--text-strong); }
h1 { margin: 0 0 32px; font-size: 44px; line-height: 1.2; }
h2 { margin: 0 0 12px; font-size: 24px; line-height: 1.3; }
h3 { font-size: 18px; }
p { margin: 0 0 16px; }
b { color: var(--text-strong); font-weight: 600; }
code { font-size: 14px; word-break: break-all; color: var(--text-strong); }
ol, ul { padding-left: 22px; }
li { margin-bottom: 8px; }

.tag { display: inline-block; padding: 4px 12px; font-size: 13px; font-weight: 600; letter-spacing: 2px; color: var(--accent-ink); background: var(--accent); }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  height: 48px; padding: 0 28px;
  font-weight: 600; color: var(--accent-ink); background: var(--accent); text-decoration: none;
}
.btn:hover { background: #fff; }
.btn.ghost { color: var(--text-strong); background: rgb(17 19 21 / 0.45); box-shadow: inset 0 0 0 1px var(--accent); }
.btn.ghost:hover { background: rgb(17 19 21 / 0.7); }
.btn, .tag, .lang button { text-shadow: none; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 0 0 16px; }
.note { color: var(--text-dim); font-size: 14px; }
.num { display: block; margin-bottom: 8px; font: 600 15px "Noto Serif", Georgia, serif; letter-spacing: 2px; color: var(--gold); }

/* Home: the hero fills the first screen, the three pillars below it. */
.home { padding-top: 0; }
.hero { min-height: calc(100vh - 72px); display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; padding: 40px 0 80px; }
.hero h1 { margin: 20px 0 16px; font-size: clamp(40px, 7vw, 76px); line-height: 1.1; text-shadow: 0 2px 20px rgb(0 0 0 / 0.65); }
.lead { max-width: 620px; margin: 0 auto 32px; font-size: 18px; color: var(--text); }
.hero .actions { justify-content: center; }
.pillars { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; padding: 40px 0; }
.pillars p { color: var(--text); }

/* Home, below the pillars: the loop, features, how to play. */
.block { padding: 56px 0 0; }
.block > h2 { font-size: 32px; margin-bottom: 12px; }
.intro { max-width: 620px; margin-bottom: 32px; color: var(--text); }
.block h3 { margin: 0 0 8px; font-size: 18px; line-height: 1.35; }
.block li p, .features p { margin: 0; }
.loop { list-style: none; padding: 0; margin: 0 0 24px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.loop li { position: relative; margin: 0; }
/* The arrow between steps, centred in the 40px gap. */
.loop li + li::before { content: "→"; position: absolute; left: -30px; top: 0; font: 600 18px "Noto Serif", Georgia, serif; color: var(--gold); }
.again { color: var(--gold); font-weight: 600; }
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px 40px; }
.block .steps { margin-bottom: 40px; }
.keys-title { margin-top: 0; }
.keys { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(5, 1fr); gap: 5px 24px; }
.keys li { margin: 0; display: flex; align-items: center; gap: 10px; }
kbd {
  display: inline-block; min-width: 28px; padding: 0 6px;
  font: 600 13px/24px "Be Vietnam Pro", sans-serif; text-align: center; text-shadow: none;
  color: var(--text-strong); background: rgb(17 19 21 / 0.6); box-shadow: inset 0 0 0 1px var(--line);
}

/* Pages: one text column on the header's left edge. */
.page > section, .page > h1 { max-width: 720px; }
.page > section + section { margin-top: 56px; }
.steps { list-style: none; padding: 0; margin: 0 0 24px; display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px 40px; }
.steps li { margin: 0; }
.steps p { margin: 0; }
.cols { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.cols section { display: flex; flex-direction: column; align-items: flex-start; }
.text > .panel, .text > p { max-width: 720px; }
.panel + .panel { margin-top: 40px; }

footer { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; padding-top: 20px; padding-bottom: 24px; color: var(--text-dim); font-size: 14px; }
footer .links { display: flex; gap: 20px; }
footer a { color: var(--text-dim); text-decoration: none; }
footer a:hover { color: var(--text-strong); }

@media (max-width: 760px) {
  header { height: auto; padding-top: 16px; padding-bottom: 8px; flex-wrap: wrap; }
  nav { gap: 16px; }
  .hero { min-height: calc(100vh - 110px); }
  .pillars, .cols, .steps, .loop, .features { grid-template-columns: 1fr; gap: 28px; }
  .loop li + li::before { content: "↓"; left: auto; right: 0; }
  .keys { grid-template-columns: repeat(2, 1fr); }
  h1 { font-size: 34px; }
}
[lang="vi"] .en, [lang="en"] .vi { display: none; }