:root {
  --bg: #f6f8fc;
  --card: #ffffff;
  --ink: #0e1726;
  --ink-2: #33415a;
  --muted: #64718a;
  --line: #e2e8f2;
  --line-2: #cfd8e6;
  --blue: #2f6db3;
  --blue-d: #1d4f8a;
  --blue-soft: #e8f0fb;
  --yellow: #ffd43b;
  --yellow-d: #e8b800;
  --green: #12935a;
  --red: #c8352b;
  --amber: #a86400;
  --code-bg: #0c1424;
  --code-ink: #dde5f2;
  --code-line: #1c2740;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(14, 23, 38, .05), 0 10px 28px -14px rgba(14, 23, 38, .22);
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --sans: "Plus Jakarta Sans", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --lh: 21px;
  --pad: 12px;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.65 var(--sans); }
[hidden] { display: none !important; }
img, svg, canvas { max-width: 100%; }
a { color: var(--blue-d); text-underline-offset: 3px; }
a:hover { color: var(--blue); }
code, kbd, pre { font-family: var(--mono); font-size: .9em; }
:not(pre) > code { background: #edf1f8; border: 1px solid var(--line); border-radius: 6px; padding: .05em .35em; }
kbd { background: #fff; border: 1px solid var(--line-2); border-bottom-width: 2px; border-radius: 5px; padding: 0 .35em; font-size: .8em; }
h1, h2, h3, h4 { line-height: 1.2; letter-spacing: -.02em; margin: 0 0 .5em; font-weight: 800; }
h1 { font-size: clamp(1.9rem, 4.2vw, 2.9rem); }
h2 { font-size: clamp(1.4rem, 2.6vw, 1.8rem); margin-top: 1.8em; }
h3 { font-size: 1.12rem; margin-top: 1.4em; }
.wrap { width: min(1200px, 100% - 32px); margin-inline: auto; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 12px; top: 12px; z-index: 99; background: #fff; padding: 8px 12px; border-radius: 8px; }
:focus-visible { outline: 3px solid color-mix(in srgb, var(--blue) 50%, transparent); outline-offset: 2px; }

/* play strip + nav */
.strip { background: var(--ink); color: #dfe7f5; font-size: .86rem; }
.strip .wrap { display: flex; gap: 10px; align-items: center; justify-content: center; min-height: 38px; flex-wrap: wrap; padding: 4px 0; }
.strip a { color: var(--yellow); font-weight: 700; }
.nav { position: sticky; top: 0; z-index: 40; background: color-mix(in srgb, var(--bg) 90%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.nav-in { display: flex; align-items: center; gap: 16px; height: 62px; }
.brand { display: inline-flex; align-items: center; gap: 9px; color: var(--ink); text-decoration: none; font-weight: 800; font-size: 1.12rem; letter-spacing: -.02em; }
.brand b { color: var(--blue); }
.nav-links { display: flex; gap: 2px; margin-left: auto; }
.nav-links a { color: var(--ink-2); text-decoration: none; font-size: .92rem; font-weight: 600; padding: 7px 11px; border-radius: 9px; }
.nav-links a:hover, .nav-links a[aria-current] { background: #e9eef7; color: var(--ink); }
.nav .menu-btn { display: none; margin-left: auto; }
@media (max-width: 900px) {
  .nav .menu-btn { display: inline-flex; }
  .nav-links { display: none; position: absolute; top: 62px; left: 0; right: 0; flex-direction: column; background: #fff; border-bottom: 1px solid var(--line); padding: 8px 16px 14px; box-shadow: var(--shadow); }
  .nav-links.open { display: flex; }
}

/* buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 7px; font: 700 .88rem var(--sans); padding: 8px 14px; border-radius: 10px;
  border: 1px solid var(--line-2); background: #fff; color: var(--ink); cursor: pointer; text-decoration: none; white-space: nowrap; line-height: 1.2; }
.btn:hover { border-color: var(--ink-2); color: var(--ink); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn.run { background: var(--green); border-color: var(--green); color: #fff; }
.btn.run:hover { background: #0d7a4a; }
.btn.stop { background: var(--red); border-color: var(--red); color: #fff; }
.btn.primary { background: var(--blue); border-color: var(--blue); color: #fff; }
.btn.primary:hover { background: var(--blue-d); color: #fff; }
.btn.yellow { background: var(--yellow); border-color: var(--yellow-d); color: var(--ink); }
.btn.ghost { background: transparent; }
.btn.sm { padding: 6px 10px; font-size: .82rem; border-radius: 8px; }
.btn svg { width: 16px; height: 16px; flex: none; }
select.inp, input.inp { font: 500 .9rem var(--sans); padding: 7px 10px; border: 1px solid var(--line-2); border-radius: 9px; background: #fff; color: var(--ink); min-width: 0; }
.hidden-input { position: absolute; width: 1px; height: 1px; opacity: 0; }

/* hero */
.hero { padding: 30px 0 10px; }
.hero h1 { max-width: 22ch; }
.hero h1 em { font-style: normal; color: var(--blue); background: linear-gradient(transparent 62%, color-mix(in srgb, var(--yellow) 70%, transparent) 62%); }
.lede { font-size: 1.1rem; color: var(--ink-2); max-width: 66ch; margin: 0 0 14px; }
.badges { display: flex; flex-wrap: wrap; gap: 8px; margin: 0; padding: 0; list-style: none; }
.badges li { font-size: .8rem; font-weight: 700; color: var(--ink-2); background: #fff; border: 1px solid var(--line); border-radius: 999px; padding: 4px 11px; }
.badges li::before { content: "✓ "; color: var(--green); }

/* code editor */
.ed { position: relative; display: flex; background: var(--code-bg); border-radius: 0; min-height: calc(var(--min-lines, 16) * var(--lh) + 2 * var(--pad)); font: 14px/var(--lh) var(--mono); }
.ed-g { flex: none; width: 46px; padding: var(--pad) 10px var(--pad) 0; text-align: right; color: #4b5a78; white-space: pre; overflow: hidden; user-select: none; border-right: 1px solid var(--code-line); background: #0a111f; }
.ed-s { position: relative; flex: 1; min-width: 0; }
.ed-h, .ed textarea { position: absolute; inset: 0; margin: 0; padding: var(--pad) 14px; font: inherit; white-space: pre; overflow: auto; tab-size: 4; letter-spacing: 0; word-wrap: normal; }
.ed-h { color: var(--code-ink); pointer-events: none; scrollbar-width: none; }
.ed-h::-webkit-scrollbar { display: none; }
.ed textarea { background: transparent; color: transparent; caret-color: var(--yellow); border: 0; outline: none; resize: none; -webkit-text-fill-color: transparent; }
.ed textarea::selection { background: rgba(120, 160, 255, .3); -webkit-text-fill-color: transparent; }
.ed i { font-style: normal; }
.t-k { color: #ff8fb1; } .t-s { color: #a8e48b; } .t-c { color: #6c7b99; font-style: italic !important; } .t-n { color: #ffcb6b; }
.t-b { color: #7cc7ff; } .t-f { color: #ffd43b; } .t-d { color: #c792ea; }
.ed-mark { position: absolute; left: 0; right: 0; height: var(--lh); background: rgba(255, 212, 59, .14); border-left: 3px solid var(--yellow); pointer-events: none; }

/* IDE */
.ide { background: var(--card); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow); overflow: hidden; margin: 16px 0 8px; }
.ide-bar { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; padding: 10px 12px; border-bottom: 1px solid var(--line); background: #f8fafd; }
.ide-bar .grow { flex: 1; }
.sep { width: 1px; height: 22px; background: var(--line-2); margin: 0 3px; }
.ide-panes { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); min-height: 480px; }
.ide-pane { display: flex; flex-direction: column; min-width: 0; }
.ide-pane + .ide-pane { border-left: 1px solid var(--line); }
.pane-head { display: flex; align-items: center; justify-content: space-between; gap: 8px; font: 700 .72rem var(--sans); text-transform: uppercase; letter-spacing: .08em; color: var(--muted); padding: 7px 12px; border-bottom: 1px solid var(--line); min-height: 40px; }
.pane-head .st { text-transform: none; letter-spacing: 0; font-weight: 600; }
.ide-pane .ed { flex: 1; }
.seg { display: inline-flex; background: #e8edf6; border-radius: 10px; padding: 3px; }
.seg button { border: 0; background: transparent; font: 700 .8rem var(--sans); padding: 5px 11px; border-radius: 8px; color: var(--ink-2); cursor: pointer; }
.seg button[aria-selected="true"] { background: #fff; color: var(--ink); box-shadow: 0 1px 2px rgba(0, 0, 0, .08); }
.console { flex: 1; margin: 0; padding: 12px 14px; background: #0a111f; color: #e7edf7; font: 13.5px/1.55 var(--mono); white-space: pre-wrap; word-break: break-word; overflow: auto; min-height: 220px; max-height: 560px; }
.console .err { color: #ff8a80; }
.console:empty::before { content: attr(data-empty); color: #5c6a88; }
.ask { display: flex; gap: 6px; padding: 8px; background: #101a2e; border-top: 1px solid var(--code-line); }
.ask input { flex: 1; min-width: 0; background: #0a111f; color: #fff; border: 1px solid #2c3a5a; border-radius: 8px; padding: 7px 10px; font: 13.5px var(--mono); }
.out-panel { flex: 1; display: flex; flex-direction: column; min-height: 0; }
.turtle-wrap { flex: 1; display: grid; place-items: center; background: #eef2f8; padding: 10px; min-height: 300px; }
.turtle-wrap canvas { width: 100%; height: auto; max-height: 520px; border-radius: 10px; box-shadow: 0 2px 10px rgba(0, 0, 0, .1); background: #fff; }
.plots { flex: 1; overflow: auto; padding: 10px; display: grid; gap: 10px; background: #fff; }
.plots img { width: 100%; border: 1px solid var(--line); border-radius: 8px; }
.ide-foot { display: flex; flex-wrap: wrap; gap: 6px 16px; padding: 7px 12px; border-top: 1px solid var(--line); font-size: .8rem; color: var(--muted); background: #f8fafd; }
.pill { display: inline-flex; align-items: center; gap: 6px; font-weight: 700; }
.pill::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--muted); }
.pill.ok::before { background: var(--green); } .pill.busy::before { background: var(--yellow-d); animation: blink 1s infinite; } .pill.bad::before { background: var(--red); }
@keyframes blink { 50% { opacity: .3; } }
.ide.full { position: fixed; inset: 0; z-index: 80; margin: 0; border-radius: 0; display: flex; flex-direction: column; }
.ide.full .ide-panes { flex: 1; min-height: 0; }
@media (max-width: 900px) {
  .ide-panes { grid-template-columns: 1fr; }
  .ide-pane + .ide-pane { border-left: 0; border-top: 1px solid var(--line); }
  .ide-pane .ed { min-height: 300px; }
  .hide-sm { display: none !important; }
}

/* pages */
.page { padding: 22px 0 40px; }
.crumbs { display: flex; flex-wrap: wrap; gap: 6px; list-style: none; margin: 0 0 14px; padding: 0; font-size: .84rem; color: var(--muted); }
.crumbs li + li::before { content: "/"; margin-right: 6px; color: var(--line-2); }
.crumbs a { color: var(--muted); text-decoration: none; }
.page-head { max-width: 860px; margin-bottom: 18px; }
.kicker { font: 800 .76rem var(--sans); text-transform: uppercase; letter-spacing: .1em; color: var(--blue); margin: 0 0 8px; }
.panel { background: var(--card); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow); overflow: hidden; }
.panel-pad { padding: 16px; }
.article-grid { display: grid; grid-template-columns: minmax(0, 1fr) 250px; gap: 40px; margin-top: 30px; align-items: start; }
.article-grid.solo { grid-template-columns: minmax(0, 800px); }
@media (max-width: 980px) { .article-grid { grid-template-columns: minmax(0, 1fr); } .toc { display: none; } }
.prose { max-width: 800px; min-width: 0; }
.prose p, .prose li { color: var(--ink-2); }
.prose h2, .prose h3 { scroll-margin-top: 80px; }
.prose table { width: 100%; border-collapse: collapse; font-size: .93rem; margin: 1em 0; display: block; overflow-x: auto; }
.prose th, .prose td { border: 1px solid var(--line); padding: 8px 10px; text-align: left; vertical-align: top; }
.prose th { background: #eef2f9; color: var(--ink); }
.prose pre { background: var(--code-bg); color: var(--code-ink); padding: 14px 16px; border-radius: 12px; overflow-x: auto; line-height: 1.55; position: relative; }
.prose pre .try { position: absolute; top: 8px; right: 8px; font: 700 .72rem var(--sans); background: var(--yellow); color: var(--ink); border-radius: 7px; padding: 4px 9px; text-decoration: none; }
.prose blockquote { margin: 1em 0; padding: 4px 16px; border-left: 4px solid var(--yellow-d); background: #fffbe6; border-radius: 0 10px 10px 0; }
.answer { background: #fff; border: 1px solid var(--line); border-left: 4px solid var(--blue); border-radius: 12px; padding: 14px 18px; margin: 0 0 18px; }
.answer p { margin: 0; color: var(--ink); }
.answer strong:first-child { display: block; font: 800 .72rem var(--sans); text-transform: uppercase; letter-spacing: .1em; color: var(--blue); margin-bottom: 4px; }
.note { font-size: .9rem; background: #ebf7f1; border: 1px solid #c8e9d8; border-radius: 10px; padding: 10px 14px; color: #155c3b !important; }
.meta-line { font-size: .86rem; color: var(--muted); margin: 10px 0 0; }
.toc { position: sticky; top: 84px; background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 14px 16px; font-size: .88rem; }
.toc b { display: block; font: 800 .7rem var(--sans); text-transform: uppercase; letter-spacing: .1em; color: var(--muted); margin-bottom: 6px; }
.toc ol { margin: 0; padding-left: 1.1em; }
.toc a { color: var(--ink-2); text-decoration: none; }
.faq details { border: 1px solid var(--line); border-radius: 12px; background: #fff; margin-bottom: 8px; }
.faq summary { cursor: pointer; padding: 12px 40px 12px 16px; font-weight: 700; list-style: none; position: relative; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 16px; top: 10px; font-size: 1.2rem; color: var(--muted); }
.faq details[open] summary::after { content: "−"; }
.faq details p { margin: 0; padding: 0 16px 14px; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 12px; }
.card { display: flex; flex-direction: column; gap: 4px; background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 15px 16px; text-decoration: none; color: var(--ink); transition: border-color .15s, transform .15s; }
.card:hover { border-color: var(--blue); transform: translateY(-2px); color: var(--ink); }
.card .k { font: 800 .66rem var(--sans); text-transform: uppercase; letter-spacing: .1em; color: var(--blue); }
.card b { font-size: 1.02rem; }
.card .d { font-size: .88rem; color: var(--muted); line-height: 1.5; }
.card .ico { font-size: 1.6rem; line-height: 1; }
.section { padding: 26px 0; }
.sub { color: var(--muted); margin: -4px 0 18px; max-width: 70ch; }
.feat { display: grid; grid-template-columns: repeat(auto-fill, minmax(255px, 1fr)); gap: 12px; }
.feat div { background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 16px; }
.feat h3 { margin: 0 0 4px; font-size: 1rem; }
.feat p { margin: 0; font-size: .92rem; color: var(--ink-2); }
.cmp-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 14px; background: #fff; }
.cmp { width: 100%; border-collapse: collapse; font-size: .92rem; }
.cmp th, .cmp td { padding: 10px 12px; border-bottom: 1px solid var(--line); text-align: left; }
.cmp th { background: #eef2f9; }
.cmp td.y { color: var(--green); font-weight: 700; } .cmp td.n { color: var(--red); }
.app-cta { display: grid; grid-template-columns: auto 1fr auto; gap: 16px; align-items: center; background: var(--ink); color: #e5ecf7; border-radius: 18px; padding: 18px 20px; margin: 26px 0; }
.app-cta b { color: #fff; font-size: 1.05rem; }
.app-cta p { margin: 2px 0 0; color: #b7c4da !important; font-size: .92rem; }
.app-cta img { width: 56px; height: 56px; border-radius: 14px; }
@media (max-width: 640px) { .app-cta { grid-template-columns: auto 1fr; } .app-cta .btn { grid-column: 1 / -1; } }

/* checker / visualizer / exercises */
.issues { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.issues li { display: grid; grid-template-columns: auto 1fr; gap: 10px; align-items: start; padding: 9px 12px; border: 1px solid var(--line); border-radius: 10px; background: #fff; font-size: .92rem; }
.issues .hint { display: block; color: var(--muted); font-size: .86rem; margin-top: 2px; }
.lv { font: 800 .66rem var(--sans); text-transform: uppercase; letter-spacing: .06em; padding: 3px 7px; border-radius: 6px; }
.lv.error { background: #fde7e5; color: var(--red); } .lv.warning { background: #fff2d6; color: var(--amber); }
.lv.info { background: #e6effc; color: var(--blue-d); } .lv.ok { background: #e1f5ea; color: var(--green); }
.ln { color: var(--blue-d); font-size: .8rem; font-weight: 700; cursor: pointer; }
.two { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
.two > * { min-width: 0; }
.two > * + * { border-left: 1px solid var(--line); }
@media (max-width: 900px) { .two { grid-template-columns: minmax(0, 1fr); } .two > * + * { border-left: 0; border-top: 1px solid var(--line); } }
.viz-ctrl { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; padding: 10px 12px; border-top: 1px solid var(--line); background: #f8fafd; }
.viz-ctrl input[type=range] { flex: 1; min-width: 140px; accent-color: var(--blue); }
.frames { padding: 12px; display: grid; gap: 10px; align-content: start; overflow: auto; max-height: 520px; }
.frame { border: 1px solid var(--line); border-radius: 12px; background: #fff; overflow: hidden; }
.frame h4 { margin: 0; padding: 7px 12px; background: #eef2f9; font-size: .82rem; }
.frame.top h4 { background: #fff3c4; }
.frame table { width: 100%; border-collapse: collapse; font: 13px var(--mono); }
.frame td { padding: 5px 12px; border-top: 1px solid var(--line); vertical-align: top; word-break: break-word; }
.frame td:first-child { width: 34%; font-weight: 600; color: var(--ink); }
.frame td .ty { display: block; font: 600 .66rem var(--sans); color: var(--muted); text-transform: uppercase; }
.frame td.chg { background: #fff8db; }
.exercise { background: #fff; border: 1px solid var(--line); border-radius: 16px; margin: 18px 0; overflow: hidden; box-shadow: var(--shadow); }
.exercise .ex-head { padding: 14px 16px 6px; }
.exercise .ex-head h3 { margin: 0 0 6px; font-size: 1.08rem; }
.exercise .ex-head p { margin: 0 0 6px; }
.lvl { font: 800 .66rem var(--sans); text-transform: uppercase; letter-spacing: .08em; padding: 3px 8px; border-radius: 6px; background: #e1f5ea; color: var(--green); margin-left: 6px; vertical-align: middle; }
.lvl.medium { background: #fff2d6; color: var(--amber); } .lvl.hard { background: #fde7e5; color: var(--red); }
.ex-bar { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; padding: 10px 12px; border-top: 1px solid var(--line); background: #f8fafd; }
.results { list-style: none; margin: 0; padding: 0 12px 12px; display: grid; gap: 6px; }
.results li { font-size: .9rem; padding: 8px 10px; border-radius: 9px; background: #f6f8fc; border: 1px solid var(--line); }
.results li.pass { background: #ebf8f1; border-color: #c4e8d4; }
.results li.fail { background: #fdf0ef; border-color: #f2cdc9; }
.results pre { margin: 6px 0 0; font-size: .8rem; background: #0c1424; color: #dde5f2; padding: 8px 10px; border-radius: 8px; white-space: pre-wrap; }
.ex-sol { margin: 0 12px 12px; }
.ex-sol summary { cursor: pointer; font-weight: 700; font-size: .9rem; color: var(--blue-d); }
.ex-sol pre { margin: 8px 0 0; background: var(--code-bg); color: var(--code-ink); padding: 12px 14px; border-radius: 10px; overflow-x: auto; font-size: .85rem; }
.progress { display: flex; align-items: center; gap: 10px; font-size: .9rem; font-weight: 700; }
.progress .bar { flex: 1; height: 10px; background: #e5ebf5; border-radius: 99px; overflow: hidden; min-width: 120px; }
.progress .bar i { display: block; height: 100%; background: linear-gradient(90deg, var(--green), #3fcf8e); width: 0; transition: width .4s; }

/* games */
.game { background: var(--card); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow); overflow: hidden; }
.game-top { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; justify-content: space-between; padding: 12px 14px; border-bottom: 1px solid var(--line); background: #f8fafd; }
.game-top h2 { margin: 0; font-size: 1.05rem; }
.stat { display: inline-flex; gap: 6px; align-items: baseline; font-size: .82rem; color: var(--muted); font-weight: 700; }
.stat b { font-size: 1.15rem; color: var(--ink); }
.game-stage { display: grid; place-items: center; background: radial-gradient(circle at 30% 20%, #18284a, #0a1120); padding: 14px; }
.game-stage canvas { width: 100%; max-width: 520px; height: auto; border-radius: 12px; image-rendering: pixelated; }
.levels { display: flex; flex-wrap: wrap; gap: 6px; }
.levels button { width: 34px; height: 34px; border-radius: 9px; border: 1px solid var(--line-2); background: #fff; font: 800 .85rem var(--sans); cursor: pointer; }
.levels button.on { background: var(--blue); color: #fff; border-color: var(--blue); }
.levels button.done { background: #e1f5ea; border-color: #b9e3cc; color: var(--green); }
.levels button.on.done { background: var(--green); color: #fff; }
.brief { padding: 12px 14px; border-bottom: 1px solid var(--line); font-size: .95rem; }
.brief p { margin: 0 0 6px; }
.toast { position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%); background: var(--ink); color: #fff; padding: 10px 18px; border-radius: 12px; font-weight: 700; z-index: 90; box-shadow: var(--shadow); }
.type-box { padding: 16px; font: 15px/1.7 var(--mono); background: var(--code-bg); color: #5b6a8a; white-space: pre-wrap; min-height: 200px; }
.type-box .ok { color: #a8e48b; } .type-box .bad { color: #fff; background: #c8352b; border-radius: 2px; } .type-box .cur { border-left: 2px solid var(--yellow); margin-left: -1px; }
.type-in { position: absolute; opacity: 0; width: 1px; height: 1px; }
.lines-puzzle { list-style: none; margin: 0; padding: 12px; display: grid; gap: 6px; background: var(--code-bg); min-height: 220px; }
.lines-puzzle li { display: flex; align-items: center; gap: 8px; font: 14px var(--mono); color: var(--code-ink); }
.lines-puzzle li code { flex: 1; background: #16223a !important; border: 1px solid #24345a !important; color: var(--code-ink); border-radius: 8px; padding: 6px 10px !important; white-space: pre; cursor: grab; }
.lines-puzzle li .ib { flex: none; width: 30px; height: 30px; border-radius: 8px; border: 1px solid #2c3a5a; background: #101a2e; color: #cfe0ff; cursor: pointer; font: 800 .9rem var(--sans); }
.lines-puzzle li.ok code { border-color: #2f9d65 !important; }

/* footer */
.foot { border-top: 1px solid var(--line); background: #eef2f8; padding: 36px 0 22px; margin-top: 30px; font-size: .9rem; }
.foot-cols { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr 1fr; gap: 26px; }
@media (max-width: 900px) { .foot-cols { grid-template-columns: 1fr 1fr; } .foot-cols > div:first-child { grid-column: 1 / -1; } }
.foot h4 { font: 800 .72rem var(--sans); text-transform: uppercase; letter-spacing: .1em; color: var(--muted); margin: 0 0 8px; }
.foot ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 5px; }
.foot a { color: var(--ink-2); text-decoration: none; }
.foot a:hover { color: var(--blue); }
.foot p { color: var(--muted); }
.foot-base { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; border-top: 1px solid var(--line-2); margin-top: 22px; padding-top: 14px; font-size: .82rem; color: var(--muted); }
.foot-base p { margin: 0; }