/* Lattice Swap - a quiet puzzle table: oat paper, soft clay tiles, a garden green and a honey yellow. */
:root, [data-theme="light"] {
  --bg: #f4f0e8; --bg-2: #ebe5d8; --card: #fffdf8; --ink: #23252b; --ink-2: #4b4f58; --muted: #7c7f87; --line: #d9d2c3; --soft: #e8e2d5;
  --tile: #fbf8f1; --tile-edge: #d6cfbf; --tile-ink: #2a2d33;
  --g: #4f9d69; --g-ink: #ffffff; --g-edge: #3c7f53; --y: #e3b341; --y-ink: #2a2310; --y-edge: #bf9330; --x: #cfc9bc; --x-ink: #3d3f45; --x-edge: #b6af9f;
  --accent: #2f6f62; --accent-ink: #ffffff; --warn: #a65b12; --bad: #a33a3a; --ok: #2f7a4a;
  --shadow: 0 1px 0 rgba(0,0,0,.04), 0 6px 18px rgba(60,50,30,.08);
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #1b1d21; --bg-2: #23262b; --card: #24272d; --ink: #ecebe6; --ink-2: #c9c7c0; --muted: #969891; --line: #3a3e45; --soft: #30343a;
    --tile: #2e3238; --tile-edge: #1f2226; --tile-ink: #f0eee8;
    --g: #4f9d69; --g-edge: #356f4a; --y: #d9a93a; --y-edge: #a8822b; --x: #4a4e55; --x-ink: #e6e4de; --x-edge: #36393f;
    --accent: #6fb8a6; --accent-ink: #10201c; --warn: #e0a15a; --bad: #e07a7a; --ok: #7cc995; --shadow: 0 6px 18px rgba(0,0,0,.35);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #1b1d21; --bg-2: #23262b; --card: #24272d; --ink: #ecebe6; --ink-2: #c9c7c0; --muted: #969891; --line: #3a3e45; --soft: #30343a;
  --tile: #2e3238; --tile-edge: #1f2226; --tile-ink: #f0eee8;
  --g: #4f9d69; --g-edge: #356f4a; --y: #d9a93a; --y-edge: #a8822b; --x: #4a4e55; --x-ink: #e6e4de; --x-edge: #36393f;
  --accent: #6fb8a6; --accent-ink: #10201c; --warn: #e0a15a; --bad: #e07a7a; --ok: #7cc995; --shadow: 0 6px 18px rgba(0,0,0,.35);
  color-scheme: dark;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--bg); color: var(--ink); font: 16px/1.5 var(--sans); }
a { color: var(--accent); }
button { font: inherit; color: inherit; cursor: pointer; }
button:disabled { cursor: not-allowed; opacity: .55; }
.hidden { display: none !important; }

/* header */
.bar { display: flex; align-items: center; gap: 12px; padding: 10px 16px; border-bottom: 1px solid var(--line); background: var(--bg); position: sticky; top: 0; z-index: 5; flex-wrap: wrap; }
.back { color: var(--muted); text-decoration: none; font-size: 14px; }
.brand { display: flex; align-items: center; gap: 8px; font-family: var(--serif); font-size: 19px; margin-right: auto; }
.mark { display: inline-grid; grid-template-columns: 8px 8px; gap: 3px; }
.mark i { width: 8px; height: 8px; border-radius: 2px; background: var(--g); }
.mark i:nth-child(2) { background: var(--y); } .mark i:nth-child(3) { background: var(--x); }
.session { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.credits { font: 600 13px var(--mono); color: var(--ink-2); }
.pill { border: 1px solid var(--line); background: var(--card); border-radius: 999px; padding: 6px 14px; font-size: 14px; text-decoration: none; color: var(--ink); display: inline-block; }
.pill:hover:not(:disabled) { border-color: var(--accent); }
.pill.solid { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.link { background: none; border: 0; color: var(--accent); padding: 4px 0; text-decoration: underline; font-size: 14px; }

/* intro */
.intro { max-width: 1120px; margin: 0 auto; padding: 22px 16px 6px; }
.intro h1 { font: 600 clamp(26px, 4.4vw, 40px)/1.15 var(--serif); margin: 0 0 8px; letter-spacing: -0.01em; }
.intro h1 em { font-style: italic; color: var(--accent); }
.sub { color: var(--ink-2); margin: 0 0 14px; max-width: 720px; }
.k { display: inline-block; padding: 0 7px; border-radius: 5px; font-weight: 600; font-size: 14px; }
.k.g { background: var(--g); color: var(--g-ink); } .k.y { background: var(--y); color: var(--y-ink); } .k.x { background: var(--x); color: var(--x-ink); }
.modes { display: inline-flex; background: var(--bg-2); border-radius: 999px; padding: 4px; gap: 2px; flex-wrap: wrap; }
.mode { border: 0; background: none; padding: 7px 16px; border-radius: 999px; font-weight: 600; color: var(--ink-2); }
.mode.on { background: var(--card); color: var(--ink); box-shadow: var(--shadow); }

/* table layout */
.table { max-width: 1120px; margin: 0 auto; padding: 12px 16px 30px; display: grid; grid-template-columns: minmax(0, 1fr) 380px; gap: 24px; align-items: start; }
@media (max-width: 900px) { .table { grid-template-columns: minmax(0, 1fr); } }
.play { background: var(--card); border: 1px solid var(--line); border-radius: 18px; padding: 18px 16px 16px; box-shadow: var(--shadow); text-align: center; }
.ptitle h2 { font: 600 22px/1.2 var(--serif); margin: 0; }
.meta { font: 12px var(--mono); color: var(--muted); margin: 4px 0 0; }

/* board */
.board { --sz: min(76px, calc((100vw - 92px) / 5)); display: grid; grid-template-columns: repeat(5, var(--sz)); grid-template-rows: repeat(5, var(--sz)); gap: 8px; justify-content: center; margin: 18px auto 14px; touch-action: none; user-select: none; -webkit-user-select: none; }
.hole { border-radius: 12px; background: repeating-linear-gradient(45deg, transparent 0 6px, var(--soft) 6px 7px); opacity: .7; }
.tile { border: 0; border-radius: 12px; font: 700 calc(var(--sz) * 0.46)/1 var(--serif); display: grid; place-items: center; background: var(--tile); color: var(--tile-ink);
  box-shadow: inset 0 -4px 0 var(--tile-edge), 0 1px 2px rgba(0,0,0,.08); transition: background-color .25s, color .25s, transform .12s, box-shadow .2s; position: relative; padding: 0; }
.tile.g { background: var(--g); color: var(--g-ink); box-shadow: inset 0 -4px 0 var(--g-edge); cursor: default; }
.tile.y { background: var(--y); color: var(--y-ink); box-shadow: inset 0 -4px 0 var(--y-edge); }
.tile.x { background: var(--x); color: var(--x-ink); box-shadow: inset 0 -4px 0 var(--x-edge); }
.tile:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
.tile.sel { transform: translateY(-5px) scale(1.04); box-shadow: 0 0 0 3px var(--accent), 0 10px 18px rgba(0,0,0,.18); z-index: 2; }
.tile.lift { z-index: 3; transition: none; box-shadow: 0 14px 26px rgba(0,0,0,.25); }
.tile.still { cursor: default; }
.tile.pop { animation: pop .32s ease-out; }
.tile.nope { animation: nope .3s ease-in-out; }
.tile.wave { animation: wave .6s ease-in-out both; }
@keyframes pop { 0% { transform: scale(.82); } 60% { transform: scale(1.08); } 100% { transform: scale(1); } }
@keyframes nope { 25% { transform: translateX(-4px); } 75% { transform: translateX(4px); } }
@keyframes wave { 0%, 100% { transform: translateY(0); } 40% { transform: translateY(-12px); } }
@media (prefers-reduced-motion: reduce) { .tile, .tile.pop, .tile.nope, .tile.wave { animation: none; transition: none; } }

.counter { display: flex; justify-content: center; gap: 18px; align-items: baseline; flex-wrap: wrap; font-size: 15px; color: var(--ink-2); }
.counter b { font: 700 22px var(--serif); color: var(--ink); }
.stars { color: var(--y); letter-spacing: 2px; font-size: 18px; min-width: 1px; }
.msg { min-height: 24px; margin: 8px 0 4px; font-weight: 600; }
.msg.win { color: var(--ok); } .msg.lose { color: var(--bad); }
.controls { display: flex; gap: 8px; justify-content: center; flex-wrap: wrap; margin-top: 6px; }
.clues { margin-top: 12px; text-align: left; }
.cluelist { margin: 6px 0 0; padding-left: 0; list-style: none; display: grid; gap: 6px; }
.cluelist li { background: var(--bg); border-radius: 10px; padding: 7px 10px; font-size: 14px; }
.cluelist .slot { font: 600 11px var(--mono); text-transform: uppercase; color: var(--muted); display: block; }
.cluelist li.done { opacity: .6; }
.cluelist li.done .ans { color: var(--g); font-weight: 700; }

/* side cards */
.side { display: grid; gap: 16px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 14px 16px; box-shadow: var(--shadow); }
.card h3 { font: 600 17px var(--serif); margin: 0 0 10px; }
.note { font-size: 13px; color: var(--muted); margin: 8px 0 0; }
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; margin: 0; text-align: center; }
.stats dt { font-size: 11px; color: var(--muted); text-transform: uppercase; letter-spacing: .04em; }
.stats dd { margin: 0; font: 700 22px var(--serif); }
.tries { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; margin-bottom: 12px; }
.tries .lbl { font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; }
.try { border: 1px dashed var(--line); background: var(--bg); border-radius: 999px; padding: 4px 11px; font-size: 13px; }
.try.on { border-style: solid; border-color: var(--accent); }
form label { display: block; font-weight: 600; font-size: 14px; margin: 10px 0 4px; }
form label small, .small { font-weight: 400; color: var(--muted); font-size: 12px; }
input[type="text"], textarea { width: 100%; border: 1px solid var(--line); border-radius: 10px; padding: 9px 11px; background: var(--bg); color: var(--ink); font: 15px var(--sans); }
input[type="text"]:focus, textarea:focus { outline: 2px solid var(--accent); outline-offset: 0; }
.diff { border: 0; padding: 0; margin: 10px 0 0; display: flex; gap: 8px; flex-wrap: wrap; }
.diff legend { font-weight: 600; font-size: 14px; padding: 0; margin-bottom: 4px; }
.diff label { margin: 0; font-weight: 400; }
.diff input { position: absolute; opacity: 0; }
.diff span { display: inline-block; border: 1px solid var(--line); border-radius: 999px; padding: 5px 13px; background: var(--bg); font-size: 14px; }
.diff input:checked + span { border-color: var(--accent); background: var(--card); box-shadow: 0 0 0 2px var(--accent) inset; }
.diff input:focus-visible + span { outline: 2px solid var(--accent); }
.stat { font: 12px var(--mono); color: var(--muted); margin: 4px 0; }
.actions { display: flex; gap: 8px; flex-wrap: wrap; margin: 8px 0; }
.meter { font: 12px var(--mono); color: var(--ink-2); margin: 10px 0 6px; }
.notice { font-size: 13px; color: var(--warn); margin: 6px 0; }
.gate { font-size: 13px; color: var(--ink-2); background: var(--bg); border-radius: 10px; padding: 8px 10px; margin: 6px 0; }
.gate .pill { margin-left: 4px; padding: 3px 10px; font-size: 13px; }
.go { width: 100%; border: 0; background: var(--accent); color: var(--accent-ink); border-radius: 12px; padding: 12px; font-weight: 700; font-size: 15px; margin-top: 4px; }
.progress { margin-top: 12px; background: var(--bg); border-radius: 12px; padding: 10px 12px; }
.ptl { margin: 0 0 6px; font-weight: 600; }
.steps { list-style: none; margin: 0; padding: 0; font-size: 13px; }
.step { color: var(--muted); padding: 2px 0; } .step.active { color: var(--ink); font-weight: 600; } .step.done { color: var(--ok); }
.step-ic { font-family: var(--mono); display: inline-block; width: 14px; }
.status { font: 12px var(--mono); color: var(--muted); margin: 6px 0 0; }
.raw pre { white-space: pre-wrap; word-break: break-word; font: 12px var(--mono); max-height: 260px; overflow: auto; background: var(--bg); padding: 8px; border-radius: 8px; }
.result { margin-top: 14px; border-top: 1px solid var(--soft); padding-top: 10px; }
.result h4 { font: 600 18px var(--serif); margin: 8px 0 2px; }
.blurb { color: var(--ink-2); margin: 0 0 8px; font-size: 14px; }
.recon { list-style: none; padding: 0; margin: 0 0 6px; font-size: 13px; display: grid; gap: 4px; }
.recon li { padding: 5px 9px; border-radius: 8px; background: var(--bg); }
.recon li.warn { color: var(--warn); } .recon li.ok { color: var(--ok); } .recon li.info { color: var(--ink-2); }
.words { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 6px; }
.words li { font: 600 12px var(--mono); border: 1px solid var(--line); border-radius: 6px; padding: 2px 7px; background: var(--bg); cursor: help; }
.words li.in { background: var(--g); color: var(--g-ink); border-color: var(--g); }
.wrap { flex-wrap: wrap; }
.coderow { display: flex; gap: 6px; }
.coderow input { flex: 1; min-width: 0; font-family: var(--mono); font-size: 13px; }
.history { list-style: none; padding: 0; margin: 6px 0; display: grid; gap: 8px; }
.history li { background: var(--bg); border-radius: 10px; padding: 8px 10px; font-size: 14px; }
.history li.cur { box-shadow: 0 0 0 2px var(--accent) inset; }
.history .ht { font-weight: 600; display: block; }
.history .hm { font: 11px var(--mono); color: var(--muted); display: block; }
.history .hrow { display: flex; gap: 6px; margin-top: 6px; }
.history .pill { padding: 3px 10px; font-size: 13px; }
.foot { max-width: 1120px; margin: 0 auto; padding: 10px 16px 40px; font-size: 13px; color: var(--muted); }
.toasts { position: fixed; bottom: 16px; left: 50%; transform: translateX(-50%); display: grid; gap: 6px; z-index: 20; width: min(92vw, 460px); }
.toast { background: var(--ink); color: var(--bg); padding: 9px 14px; border-radius: 10px; font-size: 14px; box-shadow: var(--shadow); transition: opacity .5s; }
.toast.err { background: var(--bad); color: #fff; }
.toast a { color: inherit; font-weight: 700; }
.toast.gone { opacity: 0; }

/* docs pages */
.doc { max-width: 860px; margin: 0 auto; padding: 16px; }
.doc h1 { font: 600 30px/1.2 var(--serif); }
.doc h2 { font: 600 22px var(--serif); margin-top: 30px; }
.doc pre { background: #1f2329; color: #eae7df; padding: 12px; border-radius: 10px; overflow-x: auto; font: 13px/1.5 var(--mono); }
.doc code { font-family: var(--mono); font-size: 0.92em; }
.doc table { border-collapse: collapse; width: 100%; font-size: 14px; display: block; overflow-x: auto; }
.doc th, .doc td { border: 1px solid var(--line); padding: 6px 8px; text-align: left; vertical-align: top; }
.codegroup { margin: 10px 0 18px; }
.tabs { display: flex; flex-wrap: wrap; gap: 4px; margin-bottom: 4px; }
.tab { border: 1px solid var(--line); background: var(--card); padding: 3px 10px; font: 600 12px var(--mono); border-radius: 999px; }
.tab.active { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.statebox { border: 1px solid var(--line); border-radius: 12px; padding: 10px 14px; background: var(--card); }
.tokenrow { display: flex; gap: 8px; flex-wrap: wrap; margin: 8px 0; }
.tokenbox { font: 13px var(--mono); padding: 8px 10px; border: 1px dashed var(--line); border-radius: 8px; overflow-wrap: anywhere; flex: 1; }
.mini { border: 1px solid var(--line); background: var(--card); border-radius: 999px; padding: 4px 12px; font-size: 14px; }
.primary { border: 0; background: var(--accent); color: var(--accent-ink); border-radius: 999px; padding: 6px 14px; font-weight: 700; }
.muted { color: var(--muted); } .mono { font-family: var(--mono); }