/* Gomoku — one greyscale ramp (zinc), the same one the app uses. */
:root {
  --bg: #FAFAFA;
  --bg-2: #F4F4F5;
  --card: #FFFFFF;
  --line: #E4E4E7;
  --fg: #09090B;
  --fg-2: #3F3F46;
  --mute: #71717B;
  --invert-bg: #09090B;
  --invert-fg: #FAFAFA;
  --board: #E4E4E7;
  --grid: #D4D4D8;
  --radius: 22px;
  --max: 1120px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #09090B; --bg-2: #111113; --card: #18181B; --line: #27272A;
    --fg: #FAFAFA; --fg-2: #D4D4D8; --mute: #9F9FA9;
    --invert-bg: #FAFAFA; --invert-fg: #09090B;
    --board: #3F3F46; --grid: #27272A;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #09090B; --bg-2: #111113; --card: #18181B; --line: #27272A;
  --fg: #FAFAFA; --fg-2: #D4D4D8; --mute: #9F9FA9;
  --invert-bg: #FAFAFA; --invert-fg: #09090B;
  --board: #3F3F46; --grid: #27272A;
  color-scheme: dark;
}

* { box-sizing: border-box; margin: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg); color: var(--fg);
  font: 17px/1.6 Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
}
img { max-width: 100%; display: block; }
a { color: inherit; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }
@media (max-width: 600px) { .wrap { padding: 0 16px; } }

/* --- nav ------------------------------------------------------------ */
.nav {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(1.4) blur(14px); -webkit-backdrop-filter: saturate(1.4) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav .wrap { display: flex; align-items: center; gap: 28px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; letter-spacing: -.3px; text-decoration: none; font-size: 18px; }
.brand img { width: 30px; height: 30px; border-radius: 8px; }
.nav nav { display: flex; gap: 24px; margin-left: auto; font-size: 15px; }
.nav nav a { text-decoration: none; color: var(--mute); transition: color .15s; }
.nav nav a:hover { color: var(--fg); }
@media (max-width: 760px) { .nav nav .hide-sm { display: none; } }

/* --- buttons -------------------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; gap: 10px; justify-content: center;
  height: 52px; padding: 0 26px; border-radius: 999px;
  font-weight: 600; font-size: 16px; text-decoration: none; letter-spacing: -.1px;
  border: 1px solid transparent; transition: transform .15s, opacity .15s, background .15s;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--invert-bg); color: var(--invert-fg); }
.btn-ghost { border-color: var(--line); color: var(--fg); background: var(--card); }
.btn-sm { height: 38px; padding: 0 16px; font-size: 14px; }
.btn small { font-weight: 500; opacity: .65; }

/* --- type ----------------------------------------------------------- */
.eyebrow { font-size: 13px; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--mute); }
h1, h2, h3 { letter-spacing: -.03em; line-height: 1.08; }
h1 { font-size: clamp(44px, 7vw, 80px); font-weight: 800; }
h2 { font-size: clamp(32px, 4.6vw, 52px); font-weight: 750; }
h3 { font-size: 20px; font-weight: 650; letter-spacing: -.015em; line-height: 1.3; }
.lead { font-size: clamp(18px, 2vw, 21px); color: var(--mute); max-width: 36em; }
section { padding: 112px 0; }
@media (max-width: 600px) { section { padding: 72px 0; } }
.head { max-width: 720px; margin-bottom: 56px; }
.head .eyebrow { margin-bottom: 14px; }
.head .lead { margin-top: 18px; }
.center { text-align: center; margin-left: auto; margin-right: auto; }
.center .lead { margin-left: auto; margin-right: auto; }

/* --- hero ----------------------------------------------------------- */
.hero { padding: 88px 0 0; overflow: hidden; }
.hero .wrap { display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center; }
.hero .lead { margin: 24px 0 36px; }
.hero .ctas { display: flex; flex-wrap: wrap; gap: 12px; }
.hero .note { margin-top: 18px; font-size: 14px; color: var(--mute); }
.phones { position: relative; height: 640px; }
.phone {
  position: absolute; width: 300px; padding: 9px; border-radius: 44px;
  background: #18181B; box-shadow: 0 0 0 1px #3F3F46, 0 40px 80px -24px rgba(0,0,0,.45);
}
.phone img { border-radius: 36px; width: 100%; }
.phones .p1 { left: 4%; top: 30px; z-index: 2; }
.phones .p2 { right: 2%; top: 110px; transform: rotate(4deg); }
@media (max-width: 900px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .phones { height: 560px; max-width: 520px; width: 100%; margin: 0 auto; }
  .phone { width: 250px; }
}
@media (max-width: 480px) { .phones { height: 470px; } .phone { width: 200px; } .phones .p2 { top: 80px; } }

/* --- facts strip ---------------------------------------------------- */
.facts { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); background: var(--bg-2); padding: 0; }
.facts .wrap { display: grid; grid-template-columns: repeat(4, 1fr); }
.fact { padding: 34px 8px; text-align: center; }
.fact + .fact { border-left: 1px solid var(--line); }
.fact b { display: block; font-size: 40px; font-weight: 800; letter-spacing: -.04em; line-height: 1.1; }
.fact span { font-size: 14px; color: var(--mute); }
@media (max-width: 700px) {
  .facts .wrap { grid-template-columns: repeat(2, 1fr); }
  .fact:nth-child(3) { border-left: 0; }
  .fact:nth-child(n+3) { border-top: 1px solid var(--line); }
}

/* --- how to play ---------------------------------------------------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.step { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; }
.step svg { width: 100%; height: auto; margin-bottom: 22px; border-radius: 14px; }
.step p { color: var(--mute); margin-top: 8px; font-size: 16px; }
.step .n { font-size: 13px; font-weight: 700; color: var(--mute); letter-spacing: .08em; }
@media (max-width: 820px) { .steps { grid-template-columns: 1fr; } }

/* --- features ------------------------------------------------------- */
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line);
        border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.feat { background: var(--card); padding: 32px 30px; }
.feat .ic { width: 44px; height: 44px; border-radius: 12px; background: var(--bg-2); border: 1px solid var(--line);
            display: grid; place-items: center; margin-bottom: 20px; }
.feat .ic svg { width: 22px; height: 22px; stroke: var(--fg); fill: none; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.feat p { color: var(--mute); margin-top: 8px; font-size: 16px; }
@media (max-width: 900px) { .grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .grid { grid-template-columns: 1fr; } }

/* --- engine (always dark) ------------------------------------------ */
.engine { background: #09090B; color: #FAFAFA; }
.engine .eyebrow, .engine .lead { color: #9F9FA9; }
.engine .cols { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; }
.engine ul { list-style: none; padding: 0; display: grid; gap: 22px; margin-top: 36px; }
.engine li { display: grid; grid-template-columns: 28px 1fr; gap: 14px; }
.engine li b { display: block; font-weight: 650; }
.engine li span { color: #9F9FA9; font-size: 16px; }
.engine li i { width: 22px; height: 22px; border-radius: 50%; background: #FAFAFA; margin-top: 3px; box-shadow: inset 0 0 0 1.5px #71717B; }
.engine li:nth-child(even) i { background: #09090B; box-shadow: inset 0 0 0 1.5px #71717B; }
.engine .honest { margin-top: 36px; padding: 20px 22px; border: 1px solid #27272A; border-radius: 16px; color: #9F9FA9; font-size: 15px; }
.engine .honest b { color: #FAFAFA; font-weight: 600; }
.engine figure { background: #18181B; border: 1px solid #27272A; border-radius: 28px; padding: 28px; }
.engine figcaption { color: #71717B; font-size: 14px; margin-top: 16px; text-align: center; }
@media (max-width: 900px) { .engine .cols { grid-template-columns: 1fr; gap: 48px; } }

/* --- levels --------------------------------------------------------- */
.levels { display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; }
.level { border: 1px solid var(--line); border-radius: 18px; padding: 22px 20px; background: var(--card); }
.level .bar { display: flex; gap: 4px; margin-bottom: 18px; }
.level .bar i { flex: 1; height: 6px; border-radius: 3px; background: var(--line); }
.level .bar i.on { background: var(--fg); }
.level p { color: var(--mute); font-size: 15px; margin-top: 6px; line-height: 1.5; }
@media (max-width: 900px) { .levels { grid-template-columns: repeat(2, 1fr); } .level:last-child { grid-column: 1 / -1; } }
@media (max-width: 480px) { .levels { grid-template-columns: 1fr; } }

/* --- gallery -------------------------------------------------------- */
.gallery { display: flex; gap: 22px; overflow-x: auto; scroll-snap-type: x mandatory; padding: 8px 24px 28px;
           max-width: var(--max); margin: 0 auto; scrollbar-width: thin; }
.gallery .phone { position: relative; flex: 0 0 240px; scroll-snap-align: center; box-shadow: 0 0 0 1px #3F3F46, 0 24px 48px -20px rgba(0,0,0,.4); }
.gallery figure { flex: 0 0 auto; }
.gallery figcaption { text-align: center; color: var(--mute); font-size: 14px; margin-top: 14px; }

/* --- privacy band --------------------------------------------------- */
.privacy-band { background: var(--bg-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.zeros { display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; margin-top: 8px; }
.zero { background: var(--card); border: 1px solid var(--line); border-radius: 18px; padding: 24px 18px; text-align: center; }
.zero b { display: block; font-size: 34px; font-weight: 800; letter-spacing: -.04em; }
.zero span { color: var(--mute); font-size: 14px; }
@media (max-width: 800px) { .zeros { grid-template-columns: repeat(2, 1fr); } .zero:last-child { grid-column: 1 / -1; } }

/* --- roadmap -------------------------------------------------------- */
.road { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.lane { border: 1px solid var(--line); border-radius: var(--radius); padding: 26px 24px; background: var(--card); }
.lane.now { background: var(--invert-bg); color: var(--invert-fg); border-color: var(--invert-bg); }
.lane.now .tag, .lane.now li { color: color-mix(in srgb, var(--invert-fg) 70%, transparent); }
.lane .tag { font-size: 12px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--mute); }
.lane h3 { margin: 8px 0 16px; }
.lane ul { padding: 0; list-style: none; display: grid; gap: 10px; }
.lane li { font-size: 15px; color: var(--mute); padding-left: 22px; position: relative; line-height: 1.45; }
.lane li::before { content: ""; position: absolute; left: 0; top: .45em; width: 10px; height: 10px; border-radius: 50%; border: 1.5px solid currentColor; }
.lane.now li::before { background: currentColor; }
.road-note { margin-top: 22px; color: var(--mute); font-size: 14px; text-align: center; }
@media (max-width: 960px) { .road { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .road { grid-template-columns: 1fr; } }

/* --- faq ------------------------------------------------------------ */
.faq { max-width: 780px; margin: 0 auto; }
.faq details { border-bottom: 1px solid var(--line); padding: 22px 0; }
.faq summary { cursor: pointer; list-style: none; font-weight: 600; font-size: 18px; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--mute); font-weight: 400; font-size: 24px; line-height: 1; }
.faq details[open] summary::after { content: "–"; }
.faq details p { color: var(--mute); margin-top: 12px; }

/* --- cta ------------------------------------------------------------ */
.cta { text-align: center; }
.cta .box { background: var(--invert-bg); color: var(--invert-fg); border-radius: 32px; padding: 80px 24px; }
.cta .box .lead { color: color-mix(in srgb, var(--invert-fg) 65%, transparent); margin: 18px auto 34px; }
.cta .btn-primary { background: var(--invert-fg); color: var(--invert-bg); }
.cta img { width: 84px; height: 84px; border-radius: 22px; margin: 0 auto 28px; }

/* --- footer --------------------------------------------------------- */
footer { border-top: 1px solid var(--line); padding: 40px 0 56px; color: var(--mute); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 16px 28px; align-items: center; }
footer nav { display: flex; gap: 22px; margin-left: auto; flex-wrap: wrap; }
footer a { text-decoration: none; }
footer a:hover { color: var(--fg); }

/* --- document pages (privacy, support) ----------------------------- */
.doc { max-width: 760px; margin: 0 auto; padding: 88px 24px 112px; }
.doc h1 { font-size: clamp(40px, 6vw, 60px); }
.doc .meta { color: var(--mute); margin-top: 14px; }
.doc .summary { margin: 40px 0 8px; padding: 24px 26px; border-radius: 18px; background: var(--bg-2); border: 1px solid var(--line); font-size: 18px; }
.doc h2 { font-size: 26px; margin: 52px 0 14px; letter-spacing: -.02em; }
.doc p, .doc li { color: var(--fg-2); }
.doc p + p { margin-top: 14px; }
.doc ul { padding-left: 22px; display: grid; gap: 8px; margin-top: 12px; }
.doc table { width: 100%; border-collapse: collapse; margin-top: 14px; font-size: 16px; }
.doc td, .doc th { text-align: left; padding: 12px 10px; border-bottom: 1px solid var(--line); vertical-align: top; }
.doc th { color: var(--mute); font-weight: 600; font-size: 14px; }
.contact-card { margin-top: 40px; padding: 40px 32px; border-radius: 24px; background: var(--card); border: 1px solid var(--line); text-align: center; }
.contact-card .email { margin-top: 14px; color: var(--mute); font-size: 15px; }
.contact-card .btn { margin-top: 26px; height: 56px; padding: 0 32px; font-size: 17px; }
.tips { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 18px; }
.tips div { border: 1px solid var(--line); border-radius: 16px; padding: 18px 20px; background: var(--card); font-size: 15px; color: var(--mute); }
.tips b { display: block; color: var(--fg); margin-bottom: 4px; font-size: 16px; }
@media (max-width: 600px) { .tips { grid-template-columns: 1fr; } }