/* Gomoku Online — site styles (no framework, no external fonts) */
:root {
  --paper: #faf7f1;
  --card: #ffffff;
  --ink: #1c1917;
  --muted: #6b6257;
  --line: #e7dfd2;
  --line-strong: #d8cfc0;
  --accent: #166534;
  --accent-dark: #14532d;
  --accent-soft: #ecfdf3;
  --warn-soft: #fffbeb;
  --radius: 14px;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 17px;
  line-height: 1.7;
}

a { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; text-decoration-thickness: 1px; }
a:hover { color: var(--accent-dark); }

/* ---------- header ---------- */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px 24px;
  max-width: 1080px;
  margin: 0 auto;
  padding: 16px 22px;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 1.12rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
}
.brand:hover { color: var(--ink); }

.brand-stone {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, #6f6f6f, #0b0b0b 70%);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.35);
  flex: none;
}

.site-nav { display: flex; flex-wrap: wrap; gap: 4px 18px; }
.site-nav a {
  color: var(--muted);
  font-size: 0.94rem;
  font-weight: 500;
  text-decoration: none;
}
.site-nav a:hover { color: var(--ink); }

/* ---------- main ---------- */
main {
  max-width: 1080px;
  margin: 0 auto;
  padding: 28px 22px 56px;
}

/* ---------- game card ---------- */
.game-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 12px 32px rgba(63, 42, 12, 0.07);
  padding: 22px 22px 18px;
  max-width: 720px;
  margin: 0 auto 40px;
}

.game-head { margin-bottom: 16px; }

h1 {
  font-size: 1.85rem;
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin: 0 0 8px;
}

.game-sub {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  margin-bottom: 14px;
}

.control {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--muted);
}

select {
  font: inherit;
  font-size: 0.9rem;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line-strong);
  border-radius: 9px;
  padding: 7px 9px;
  cursor: pointer;
}
select:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

button {
  font: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line-strong);
  border-radius: 10px;
  padding: 8px 14px;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease, transform 0.05s ease;
}
button:hover { background: #f4eee3; }
button:active { transform: translateY(1px); }
button.primary {
  color: #fff;
  background: var(--accent);
  border-color: var(--accent);
}
button.primary:hover { background: var(--accent-dark); border-color: var(--accent-dark); }
button:disabled { opacity: 0.6; cursor: default; }

#board-wrap { display: flex; justify-content: center; margin: 4px 0 12px; }

#board {
  display: block;
  width: 100%;
  max-width: 100%;
  border-radius: 12px;
  touch-action: manipulation;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(72, 47, 12, 0.16);
}

.status {
  margin: 0;
  min-height: 1.6em;
  padding: 9px 12px;
  border-radius: 10px;
  text-align: center;
  font-weight: 600;
  font-size: 0.96rem;
  color: #44403c;
  background: #f7f3ea;
  border: 1px solid var(--line);
}
.status.win { color: var(--accent); background: var(--accent-soft); border-color: #bbf7d0; }
.status.lose { color: #b91c1c; background: #fef2f2; border-color: #fecaca; }
.status.foul { color: #b91c1c; background: #fef2f2; border-color: #fecaca; }
.status.thinking { color: #92400e; background: var(--warn-soft); border-color: #fde68a; }

/* ---------- prose / content pages ---------- */
.prose { max-width: 720px; margin: 0 auto; }
.game-card + .prose { margin-top: 8px; }

.prose h2 {
  font-size: 1.42rem;
  line-height: 1.3;
  letter-spacing: -0.015em;
  margin: 38px 0 12px;
}
.prose h3 { font-size: 1.12rem; margin: 26px 0 8px; }
.prose p { margin: 0 0 16px; color: #33302b; }
.prose ul, .prose ol { margin: 0 0 16px; padding-left: 1.35em; }
.prose li { margin-bottom: 7px; }
.prose li strong { color: var(--ink); }

.lede { font-size: 1.06rem; color: var(--muted); }

.updated {
  margin-top: 34px;
  font-size: 0.84rem;
  color: #8a8177;
  border-top: 1px solid var(--line);
  padding-top: 12px;
}

.callout {
  background: var(--accent-soft);
  border-left: 3px solid var(--accent);
  border-radius: 0 10px 10px 0;
  padding: 13px 16px;
  margin: 20px 0;
}
.callout p:last-child { margin-bottom: 0; }

.links { list-style: none; padding-left: 0; }
.links li { margin-bottom: 9px; }

.table-wrap { overflow-x: auto; margin: 16px 0 20px; }
table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.94rem;
}
th, td {
  border: 1px solid var(--line);
  padding: 9px 12px;
  text-align: left;
  vertical-align: top;
}
th { background: #f7f3ea; font-weight: 700; }
td code { font-size: 0.9em; }

details {
  border-bottom: 1px solid var(--line);
  padding: 14px 0;
}
details summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
}
details summary::-webkit-details-marker { display: none; }
details summary::before { content: "+ "; color: var(--accent); }
details[open] summary::before { content: "− "; }
details p { margin: 10px 0 0; }

/* ---------- footer ---------- */
.site-footer {
  max-width: 1080px;
  margin: 0 auto;
  padding: 22px 22px 40px;
  border-top: 1px solid var(--line);
  text-align: center;
  color: #8a8177;
  font-size: 0.85rem;
}
.site-footer p { margin: 4px 0; }
.footer-links a { color: var(--muted); text-decoration: none; }
.footer-links a:hover { color: var(--ink); }

/* ---------- mobile ---------- */
@media (max-width: 640px) {
  body { font-size: 16px; }
  .site-header { padding: 13px 16px; }
  .site-nav { gap: 2px 12px; }
  .site-nav a { font-size: 0.88rem; }
  main { padding: 18px 14px 44px; }
  .game-card { padding: 16px 14px 14px; border-radius: 16px; }
  h1 { font-size: 1.5rem; }
  .prose h2 { font-size: 1.25rem; }
  .controls { gap: 8px 10px; }
  button { padding: 8px 12px; }
}