/* AI Snake — page + board styles. Shared by /games/snake/ and /embed/snake/. */
:root{
  /* page: warm ivory chrome, deep-pine board */
  --page:#f6f1e7; --page-surface:#fffdf8; --page-surface2:#efe8da; --page-border:#d9d0bf;
  --page-ink:#1d2a24; --page-muted:#5c6b63;
  --accent:#1f9d6a; --accent-ink:#157a52; --accent-dim:rgba(31,157,106,.14); --accent-glow:rgba(31,157,106,.35);
  --board:#0f2a1f; --board-edge:#0a1f17; --cell-a:#163d2c; --cell-b:#1a4634;
  --apple:#ff7a45; --apple-leaf:#8fd672;
  --snake-a:#2ee59d; --snake-b:#b8f36a;
  --radius:18px; --shadow:0 18px 50px rgba(29,42,36,.18);
  color-scheme:light;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--page);color:var(--page-ink);font-family:'Space Grotesk',system-ui,sans-serif;line-height:1.55;-webkit-font-smoothing:antialiased}
a{color:var(--accent-ink)}
:focus-visible{outline:3px solid var(--accent);outline-offset:3px;border-radius:8px}

/* ---- site nav (games-cluster convention) ---- */
.site-nav-bar{background:var(--page-surface);border-bottom:1px solid var(--page-border);display:flex;align-items:center;justify-content:space-between;padding:0 24px;height:56px;position:sticky;top:0;z-index:200;width:100%}
.site-logo{display:flex;align-items:center;gap:8px;font-family:'Orbitron',sans-serif;font-size:1rem;font-weight:700;color:var(--accent-ink);letter-spacing:.06em;text-decoration:none}
.site-logo img{width:22px;height:22px}
.site-nav{display:flex;align-items:center;gap:6px}
.nav-link{display:inline-flex;align-items:center;justify-content:center;min-width:96px;font-size:.875rem;font-weight:700;padding:8px 12px;border:1.5px solid var(--page-border);border-radius:9px;color:var(--page-ink);background:transparent;text-decoration:none;transition:background .18s,border-color .18s,color .18s}
.nav-link:hover{background:var(--accent-ink);border-color:var(--accent-ink);color:#fff}
.nav-dropdown-btn{display:inline-flex;align-items:center;gap:6px;background:none;border:1px solid var(--page-border);cursor:pointer;padding:6px 12px;border-radius:9px;font-size:.85rem;font-weight:700;color:var(--page-ink);font-family:inherit;min-height:38px}
.nav-dropdown-btn:hover{background:var(--page-surface2)}
.nav-hamburger{display:none;align-items:center;gap:6px;background:none;border:1px solid var(--page-border);cursor:pointer;padding:6px 12px;border-radius:9px;font-size:.85rem;font-weight:700;color:var(--page-ink);font-family:inherit;min-height:38px}
.nav-mobile-menu{display:none}
.nav-mobile-menu.open{display:flex;flex-direction:column;position:fixed;top:60px;right:12px;left:auto;width:max-content;max-width:calc(100vw - 24px);max-height:min(62vh,560px);overflow-y:auto;gap:2px;padding:6px;background:var(--page-surface);border:1px solid var(--page-border);border-radius:12px;box-shadow:0 12px 28px rgba(0,0,0,.18);z-index:210}
.nav-mobile-link{padding:8px 14px;font-size:.9rem;white-space:nowrap;border-radius:8px;color:var(--page-ink);text-decoration:none;font-weight:600}
.nav-mobile-link:hover{background:var(--page-surface2)}
.nav-mobile-link.active{background:var(--accent-ink);color:#fff}
@media(max-width:640px){.nav-dropdown-btn,.site-nav .nav-link{display:none}.nav-hamburger{display:flex}}

/* ---- page frame ---- */
.sk-wrap{max-width:1040px;margin:0 auto;padding:28px 20px 60px}
.sk-hero{text-align:center;margin:8px auto 22px;max-width:680px}
.sk-hero h1{font-family:'Orbitron',sans-serif;font-weight:900;font-size:clamp(1.7rem,4.6vw,2.6rem);letter-spacing:.02em;margin:0 0 10px;color:var(--page-ink)}
.sk-hero p{margin:0;color:var(--page-muted);font-size:1.02rem}

/* ---- stats strip ---- */
.sk-stats{display:flex;justify-content:center;gap:14px;margin:0 auto 16px;max-width:560px}
.sk-stat{flex:1;background:var(--page-surface);border:1px solid var(--page-border);border-radius:14px;padding:10px 14px;text-align:center;min-width:0}
.sk-stat .n{font-family:'Orbitron',sans-serif;font-weight:700;font-size:1.35rem;font-variant-numeric:tabular-nums;color:var(--page-ink);line-height:1.15}
.sk-stat .l{font-size:.78rem;color:var(--page-muted);margin-top:2px}

/* ---- board ---- */
.sk-stage{position:relative;width:min(100%,560px);aspect-ratio:1/1;margin:0 auto;background:var(--board);border-radius:var(--radius);box-shadow:var(--shadow),inset 0 0 0 1px rgba(255,255,255,.04);overflow:hidden;touch-action:none;user-select:none;-webkit-user-select:none}
.sk-stage canvas{display:block;width:100%;height:100%}
.sk-overlay{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;background:rgba(10,31,23,.72);backdrop-filter:blur(3px);color:#eef7f1;text-align:center;padding:24px;transition:opacity .25s}
.sk-overlay[hidden]{display:none}
.sk-overlay .t{font-family:'Orbitron',sans-serif;font-weight:900;font-size:clamp(1.3rem,4vw,2rem);letter-spacing:.04em}
.sk-overlay .s{font-size:.95rem;opacity:.9;max-width:320px}
.sk-overlay .k{font-size:.8rem;opacity:.7}

/* ---- controls ---- */
.sk-controls{display:flex;flex-wrap:wrap;justify-content:flex-start;align-items:center;gap:8px;margin:16px auto 0;max-width:560px}
.sk-btn-icon{width:44px;padding:0;display:inline-flex;align-items:center;justify-content:center;flex:none}
.sk-btn-icon svg{width:24px;height:24px;stroke:#2563eb;flex:none}
/* On phones, let the restart button grow into the leftover space so the row
   reaches the board's right edge (icon stays centered). */
@media(max-width:560px){.sk-btn-icon{flex:1 1 auto}}
.sk-btn{appearance:none;border:1.5px solid var(--page-border);background:var(--page-surface);color:var(--page-ink);font:inherit;font-weight:700;font-size:.92rem;padding:10px 16px;border-radius:12px;cursor:pointer;min-height:44px;transition:background .15s,border-color .15s,transform .1s}
.sk-btn:hover{border-color:var(--accent-ink);background:var(--accent-dim)}
.sk-btn:active{transform:translateY(1px)}
.sk-btn.primary{background:var(--accent-ink);border-color:var(--accent-ink);color:#fff}
.sk-btn.primary:hover{background:#116444}
.sk-btn[aria-pressed="true"]{background:var(--accent-ink);border-color:var(--accent-ink);color:#fff}
.sk-seg{display:inline-flex;border:1.5px solid var(--page-border);border-radius:12px;overflow:hidden;background:var(--page-surface)}
.sk-seg button{appearance:none;border:0;background:transparent;color:var(--page-ink);font:inherit;font-weight:600;font-size:.88rem;padding:10px 14px;cursor:pointer;min-height:44px}
.sk-seg button+button{border-left:1.5px solid var(--page-border)}
.sk-seg button[aria-pressed="true"]{background:var(--accent-dim);color:var(--accent-ink)}
.sk-seg-label{font-size:.82rem;color:var(--page-muted);margin-right:4px}
.sk-group{display:inline-flex;align-items:center;gap:6px}
.sk-select{appearance:none;border:1.5px solid var(--page-border);background:var(--page-surface);color:var(--page-ink);font:inherit;font-weight:600;font-size:.88rem;padding:10px 34px 10px 14px;border-radius:12px;min-height:44px;cursor:pointer;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' fill='none' stroke='%231d2a24' stroke-width='2'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 12px center}
.sk-ai-note{text-align:center;font-size:.85rem;color:var(--page-muted);margin:10px auto 0;max-width:560px;min-height:1.3em}

/* ---- options panel (native <details>) ---- */
.sk-options{display:inline-flex;flex-direction:column;align-items:stretch}
/* When open, dissolve the <details> box so the button stays put in the row and
   only the panel drops to its own full-width row beneath all the buttons. */
.sk-options[open]{display:contents}
.sk-options[open]::details-content{flex:1 0 100%;order:99;width:100%} /* the UA content box is the real flex item */
.sk-options summary{list-style:none;cursor:pointer;align-self:center}
.sk-options summary::-webkit-details-marker{display:none}
.sk-options summary.sk-btn{background:#2563eb;border-color:#2563eb;color:#fff}
.sk-options summary.sk-btn:hover{background:#1d4ed8;border-color:#1d4ed8}
.sk-options summary.sk-btn::after{content:"▾";margin-left:8px;opacity:.85}
.sk-options[open] summary.sk-btn{background:#1d4ed8;border-color:#1d4ed8;color:#fff}
.sk-options[open] summary.sk-btn::after{content:"▴"}
.sk-options-panel{flex:1 0 100%;order:99;display:grid;gap:12px;background:var(--page-surface);border:1px solid var(--page-border);border-radius:14px;padding:14px 16px;margin-top:4px;max-width:560px;width:100%;margin-left:auto;margin-right:auto}
.sk-opt{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}
.sk-opt-label{font-size:.9rem;font-weight:600;color:var(--page-ink)}
.sk-opt .sk-seg,.sk-opt .sk-select{margin-left:auto}
@media(max-width:480px){.sk-opt{flex-direction:column;align-items:stretch}.sk-opt .sk-seg,.sk-opt .sk-select{margin-left:0}.sk-opt .sk-seg{justify-content:stretch}.sk-opt .sk-seg button{flex:1}}

/* Mobile control is drag-steer on the board itself (game.js) — no on-screen buttons. */

/* ---- content sections ---- */
.sk-section{max-width:720px;margin:44px auto 0}
.sk-section h2{font-family:'Orbitron',sans-serif;font-weight:700;font-size:1.25rem;letter-spacing:.02em;margin:0 0 12px}
.sk-section p,.sk-section li{color:#2f3d36;font-size:1rem}
.sk-section ul,.sk-section ol{padding-left:22px}
.sk-cols{display:grid;grid-template-columns:1fr 1fr;gap:22px}
@media(max-width:640px){.sk-cols{grid-template-columns:1fr}}
.sk-card{background:var(--page-surface);border:1px solid var(--page-border);border-radius:14px;padding:18px 20px}
.sk-card h3{margin:0 0 8px;font-size:1rem}
.sk-card p{margin:0;font-size:.95rem}
kbd{font-family:ui-monospace,Menlo,monospace;font-size:.82em;background:var(--page-surface2);border:1px solid var(--page-border);border-bottom-width:2px;border-radius:6px;padding:1px 6px}
.sk-faq details{border:1px solid var(--page-border);border-radius:12px;background:var(--page-surface);padding:0 18px;margin-bottom:10px}
.sk-faq summary{cursor:pointer;font-weight:700;padding:14px 0;list-style:none}
.sk-faq summary::-webkit-details-marker{display:none}
.sk-faq summary::after{content:"+";float:right;color:var(--accent-ink);font-weight:700}
.sk-faq details[open] summary::after{content:"–"}
.sk-faq .a{padding:0 0 16px;color:#2f3d36}
.sk-embed textarea{width:100%;font-family:ui-monospace,Menlo,monospace;font-size:13px;line-height:1.5;padding:14px;border-radius:12px;border:1px solid var(--page-border);background:var(--page-surface);color:var(--page-ink);resize:vertical}
.sk-related{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:12px}
.sk-related a{display:block;background:var(--page-surface);border:1px solid var(--page-border);border-radius:12px;padding:14px 16px;text-decoration:none;color:var(--page-ink);font-weight:600}
.sk-related a:hover{border-color:var(--accent-ink)}
.sk-related small{display:block;color:var(--page-muted);font-weight:400;margin-top:3px}
footer{text-align:center;color:var(--page-muted);font-size:.85rem;padding:30px 20px 40px;border-top:1px solid var(--page-border);margin-top:40px}
footer a{color:var(--accent-ink);text-decoration:none}

/* ---- embed ---- */
body.lk-embed{background:transparent}
body.lk-embed .sk-wrap{padding:12px 12px 8px}
.embed-attrib{display:block;text-align:center;padding:10px 12px;font-size:.8rem;font-weight:600;letter-spacing:.02em;color:var(--accent-ink);text-decoration:none}

@media(prefers-reduced-motion:reduce){.sk-overlay{transition:none}}