:root {
  --ink: #202124;
  --muted: #5d5a54;
  --paper: #f4f1ea;
  --card: #fffdf8;
  --line: #ddd8cd;
  --green: #1f6f43;
  --green-dark: #185737;
  --gold: #d4af37;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: var(--paper);
  color: var(--ink);
  line-height: 1.65;
}
a { color: inherit; }
.container { width: min(100% - 40px, 1080px); margin: 0 auto; }
.hero {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: #f8f5ee;
  padding: clamp(64px, 10vw, 118px) 0 clamp(58px, 8vw, 96px);
}
.hero::after {
  content: "";
  position: absolute;
  width: 420px;
  height: 420px;
  right: -190px;
  bottom: -250px;
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 50%;
  box-shadow: 0 0 0 35px rgba(255,255,255,.025), 0 0 0 70px rgba(255,255,255,.025);
  pointer-events: none;
}
.hero-inner { position: relative; z-index: 1; }
.eyebrow {
  font-size: .76rem;
  font-weight: 800;
  letter-spacing: .18em;
  line-height: 1.4;
}
.hero h1 {
  max-width: 950px;
  margin: 22px 0 0;
  font-size: clamp(3rem, 8vw, 6.5rem);
  line-height: .99;
  letter-spacing: -.065em;
}
.hero h1 span { color: #e6d9ad; }
.tagline { margin: 24px 0 0; font-size: clamp(1.1rem, 2vw, 1.4rem); font-weight: 700; }
.hero-copy { margin: 28px 0 0; font-size: clamp(1.3rem, 2.8vw, 1.85rem); font-weight: 700; line-height: 1.3; max-width: 740px; }
.hero-detail { max-width: 710px; margin: 14px 0 0; color: #d8d5ce; font-size: 1.08rem; }
.hero-actions, .about-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-top: 28px; }
.button {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  min-height: 48px;
  padding: 12px 21px;
  border: 1px solid transparent;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 800;
  line-height: 1.25;
  transition: transform .15s ease, background .15s ease, opacity .15s ease;
}
.button:hover { transform: translateY(-2px); }
.button:focus-visible, a:focus-visible { outline: 3px solid #c7a94b; outline-offset: 3px; }
.button-primary { background: #f8f5ee; color: var(--ink); }
.button-primary:hover { background: #e6d9ad; }
.button-secondary { border-color: rgba(255,255,255,.48); color: #fff; background: transparent; }
.button-secondary:hover { background: rgba(255,255,255,.09); }
.platform-note { margin: 18px 0 0; color: #c8c4bc; font-size: .9rem; }
main { padding: 34px 0 90px; }
.section {
  margin-top: 28px;
  padding: clamp(28px, 5.5vw, 58px);
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: 0 12px 35px rgba(0,0,0,.045);
}
.intro-section { margin-top: 0; }
.dark-eyebrow { color: #6d6a61; }
h2 { margin: 12px 0 18px; font-size: clamp(2rem, 4.6vw, 3.25rem); line-height: 1.08; letter-spacing: -.045em; }
h3 { margin: 0 0 10px; font-size: 1.25rem; line-height: 1.25; }
p { margin-top: 0; }
.intro-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(280px, .9fr); gap: clamp(24px, 4vw, 48px); align-items: center; }
.intro-copy p { color: var(--muted); font-size: 1.06rem; }
.board-figure { margin: 0; }
.team-chess-image { display: block; width: 100%; height: auto; }
.board-figure figcaption { margin-top: 10px; color: #77736b; font-size: .88rem; text-align: center; }
.video-section { background: #e9e5db; box-shadow: none; }
.section-lead { max-width: 760px; color: var(--muted); font-size: 1.08rem; }
.small-note { color: #716d64; font-size: .9rem; }
.video-section .small-note { margin: 16px 0 0; }
.feature-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; margin-top: 28px; }
.feature-card { padding: 24px; border: 1px solid var(--line); border-radius: 14px; background: #fff; }
.feature-number { color: var(--green); font-size: .8rem; font-weight: 800; letter-spacing: .12em; margin-bottom: 16px; }
.feature-card p { margin: 0; color: var(--muted); font-size: .98rem; }
.download-section { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(280px, .9fr); gap: 28px; margin-top: 28px; padding: clamp(28px, 5.5vw, 58px); border-radius: 20px; background: var(--ink); color: #f8f5ee; }
.download-main h2 { max-width: 600px; }
.download-intro { max-width: 600px; color: #d8d5ce; font-size: 1.08rem; }
.button-download { margin-top: 8px; background: var(--green); color: #fff; }
.button-download:hover { background: var(--green-dark); }
.download-details { margin: 12px 0 0; color: #c8c4bc; font-size: .92rem; }
.download-aside { padding: 26px; border: 1px solid rgba(255,255,255,.2); border-radius: 16px; background: rgba(255,255,255,.045); }
.download-aside p { color: #d8d5ce; }
.button-light { background: #f8f5ee; color: var(--ink); }
.button-light:hover { background: #e6d9ad; }
.download-aside .small-note { margin: 14px 0 0; color: #c8c4bc; }
.download-notice { grid-column: 1 / -1; padding: 16px 19px; border-left: 4px solid var(--gold); background: rgba(255,255,255,.07); border-radius: 0 10px 10px 0; }
.download-notice p { margin: 5px 0 0; color: #d8d5ce; font-size: .94rem; }
.online-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin-top: 28px; }
.online-card { padding: 24px; border: 1px solid var(--line); border-radius: 14px; background: #fff; }
.online-card p, .online-card li { color: var(--muted); }
.online-card ol, .online-card ul { padding-left: 22px; }
.online-card li + li { margin-top: 9px; }
.online-card .small-note { margin: 14px 0 0; }
.beta-reminder { margin: 22px 0 0; padding: 15px 18px; border-radius: 10px; background: #f3eddb; color: #51472c; }
.about-section p { max-width: 760px; color: var(--muted); font-size: 1.06rem; }
.about-actions { gap: 22px; }
.text-link { color: var(--green-dark); font-weight: 800; text-underline-offset: 4px; }
footer { border-top: 1px solid #d8d3c8; padding: 26px 0; color: #77736b; font-size: .9rem; }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px 24px; }
footer a { text-decoration: none; }
footer a:hover { text-decoration: underline; }

@media (max-width: 760px) {
  .intro-grid, .download-section { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .online-grid { grid-template-columns: 1fr; }
  .download-notice { grid-column: auto; }
  .board-figure { max-width: 560px; margin: 0 auto; }
}
@media (max-width: 520px) {
  .container { width: min(100% - 28px, 1080px); }
  .hero { padding: 60px 0 54px; }
  .hero-actions { align-items: stretch; flex-direction: column; }
  .hero-actions .button { width: 100%; }
  main { padding: 18px 0 55px; }
  .section, .download-section { padding: 25px 21px; border-radius: 15px; }
  .feature-card, .online-card, .download-aside { padding: 20px; }
  .footer-inner { flex-direction: column; gap: 8px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}