/* Chess Puzzles — design system: near-black board theme, warm gold accent,
   tournament-green board motif. Mobile-first; wider layouts layered on top. */
:root {
  --bg: #0e1014;
  --bg-2: #161922;
  --surface: #1d212c;
  --border: #2a2f3c;
  --text: #eceef2;
  --muted: #98a0ad;
  --gold: #f0b95c;
  --gold-2: #d99b3a;
  --green: #6db58c;
  --sq-light: #ead9b0;
  --sq-dark: #56795f;
  --radius: 14px;
  --maxw: 1100px;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  color: var(--text);
  background:
    radial-gradient(1100px 600px at 80% -10%, rgba(240,185,92,0.10), transparent 60%),
    radial-gradient(900px 500px at -10% 10%, rgba(109,181,140,0.08), transparent 55%),
    var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--gold); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }
h1, h2, h3 { line-height: 1.2; letter-spacing: -0.01em; }
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.muted { color: var(--muted); }

/* Header */
header.site { padding: 18px 0; border-bottom: 1px solid var(--border); }
header.site .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--text); }
.brand .mark { width: 32px; height: 32px; flex: 0 0 auto; }
.lang-switch {
  font-size: 0.95rem; padding: 8px 14px; border: 1px solid var(--border);
  border-radius: 999px; color: var(--text); min-height: 44px; display: inline-flex; align-items: center;
}

/* Hero */
.hero { padding: 56px 0 36px; text-align: center; }
.hero .mark-lg { width: 76px; height: 76px; margin: 0 auto 22px; }
.hero h1 { font-size: 2.1rem; margin: 0 0 14px; }
.hero h1 .accent { color: var(--gold); }
.hero p.lede { font-size: 1.15rem; color: var(--muted); max-width: 36ch; margin: 0 auto 26px; }
.cta-row { display: flex; flex-direction: column; gap: 12px; align-items: center; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  min-height: 52px; padding: 0 26px; border-radius: 12px; font-weight: 700; font-size: 1.05rem;
  width: 100%; max-width: 320px;
}
.btn-primary { background: linear-gradient(180deg, var(--gold), var(--gold-2)); color: #1a1205; }
.btn-primary:hover { text-decoration: none; filter: brightness(1.05); }
.btn-ghost { border: 1px solid var(--border); color: var(--text); background: var(--surface); }
.btn-ghost:hover { text-decoration: none; border-color: var(--gold); }
.hero .sub { margin-top: 16px; font-size: 0.92rem; color: var(--muted); }

/* Sections */
section { padding: 40px 0; }
section h2 { font-size: 1.6rem; margin: 0 0 8px; text-align: center; }
section .intro { color: var(--muted); text-align: center; max-width: 56ch; margin: 0 auto 30px; }

/* Feature cards */
.grid { display: grid; grid-template-columns: 1fr; gap: 16px; }
.card { background: var(--bg-2); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; }
.card .ico { font-size: 1.7rem; line-height: 1; color: var(--gold); }
.card h3 { font-size: 1.15rem; margin: 12px 0 6px; }
.card p { margin: 0; color: var(--muted); font-size: 0.98rem; }

/* Steps */
.steps { counter-reset: step; display: grid; grid-template-columns: 1fr; gap: 14px; max-width: 640px; margin: 0 auto; }
.step { display: flex; gap: 16px; align-items: flex-start; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; }
.step .n { counter-increment: step; flex: 0 0 auto; width: 38px; height: 38px; border-radius: 50%;
  display: grid; place-items: center; font-weight: 700; color: #1a1205; background: var(--gold); }
.step .n::before { content: counter(step); }
.step h3 { margin: 2px 0 4px; font-size: 1.05rem; }
.step p { margin: 0; color: var(--muted); font-size: 0.96rem; }

/* Screenshots */
.shots { display: flex; flex-wrap: wrap; gap: 26px; justify-content: center; align-items: flex-start; }
.phone { width: 230px; max-width: 70vw; border: 1px solid var(--border); border-radius: 28px;
  padding: 8px; background: #05070a; box-shadow: 0 20px 50px rgba(0,0,0,0.45); }
.phone img { border-radius: 20px; }
.phone figcaption { text-align: center; color: var(--muted); font-size: 0.88rem; padding: 10px 6px 2px; }

/* Tech list */
.tech { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; max-width: 720px; margin: 0 auto; }
.tag { border: 1px solid var(--border); background: var(--bg-2); border-radius: 999px; padding: 8px 15px; font-size: 0.9rem; color: var(--text); }

/* Footer */
footer { border-top: 1px solid var(--border); padding: 30px 0 48px; text-align: center; color: var(--muted); font-size: 0.92rem; }
footer a { color: var(--text); }

/* Breakpoints */
@media (min-width: 640px) {
  .hero h1 { font-size: 2.7rem; }
  .cta-row { flex-direction: row; justify-content: center; }
  .btn { width: auto; }
  .grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1024px) {
  .hero { padding: 80px 0 48px; }
  .hero h1 { font-size: 3.2rem; }
  .grid { grid-template-columns: repeat(3, 1fr); }
}

/* RTL / Persian */
[dir="rtl"] body { font-family: "Vazirmatn", var(--font); }
[dir="rtl"] .step { flex-direction: row; }
[dir="rtl"] .step .n::before { content: counter(step, persian); }
[dir="rtl"] h1, [dir="rtl"] h2, [dir="rtl"] h3 { letter-spacing: 0; }