/* ---------- base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { color-scheme: light; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: var(--fs-2);
  line-height: var(--lh);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration-color: var(--line-2); text-underline-offset: 3px; }
a:hover { color: var(--accent); text-decoration-color: var(--accent); }
h1, h2, h3, h4 { margin: 0; line-height: 1.25; }
h1 { font-size: var(--fs-4); font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; }
h2 { font-size: var(--fs-0); font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); margin-top: var(--s-7); margin-bottom: var(--s-3); }
h3 { font-size: var(--fs-2); font-weight: 600; margin-top: var(--s-6); margin-bottom: var(--s-2); }
p { margin: 0 0 var(--s-4); }
ul, ol { padding-left: 1.4em; margin: 0 0 var(--s-4); }
li { margin-bottom: var(--s-1); }
blockquote { margin: var(--s-5) 0; padding: 0 0 0 var(--s-4); border-left: 1px solid var(--line-2); color: var(--ink-2); }
blockquote p:last-child { margin: 0; }
code, .mono { font-family: var(--font-mono); font-size: 0.93em; }
hr { border: 0; border-top: 1px solid var(--line); margin: var(--s-6) 0; }
strong { font-weight: 600; }
button { font: inherit; color: inherit; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

.eyebrow { font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); font-weight: 600; }
.small { font-size: var(--fs-1); color: var(--ink-2); }

/* ---------- buttons (metar-taf: filled black primary, outlined uppercase secondary) ---------- */
.btn {
  /* a centred box, so any extra height (the 40px touch target on phones) stays even above and below the text */
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 11px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase;
  padding: 6px 14px; border: 1px solid var(--line-2); background: transparent; color: var(--ink);
  cursor: pointer; transition: border-color 150ms, background 150ms;
}
.btn:hover { border-color: var(--accent); color: var(--accent); }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); padding: 8px 22px; font-size: 12px; letter-spacing: 0.1em; }
.btn.primary:hover { background: var(--accent-deep); border-color: var(--accent-deep); }
.btn.quiet { border-color: var(--line-2); color: var(--ink-2); }
.btn.quiet:hover { color: var(--accent); border-color: var(--accent); }
.btn[disabled] { opacity: 0.4; cursor: default; pointer-events: none; }
.icon-btn {
  width: 32px; height: 32px; display: inline-grid; place-items: center;
  border: 1px solid var(--line-2); background: transparent; cursor: pointer; color: var(--ink-2); padding: 0;
  transition: border-color 150ms, color 150ms;
}
.icon-btn:hover { color: var(--accent); border-color: var(--accent); }
.icon-btn svg { width: 16px; height: 16px; }

/* ---------- layout ---------- */
.app { display: grid; grid-template-columns: var(--sidebar-w) minmax(0, 1fr); min-height: 100vh; }
.app > div { min-width: 0; }
.sidebar {
  position: sticky; top: 0; height: 100vh; overflow-y: auto;
  background: var(--surface); border-right: 1px solid var(--line);
  display: flex; flex-direction: column;
}
.brand {
  position: relative;
  display: flex; flex-direction: column; align-items: flex-start; gap: var(--s-3); padding: var(--s-6) var(--s-5) var(--s-5);
  font-size: 13px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase;
}
.brand .brand-text { color: inherit; text-decoration: none; }
.brand .logo-btn { display: block; padding: 0; border: 0; background: none; cursor: pointer; color: var(--accent); border-radius: var(--bubble-tile-radius); }
.brand .logo-btn:focus-visible { outline: 1px solid var(--accent); outline-offset: 3px; }
.brand .logo { width: 44px; height: 44px; margin: -6px 0 0 -6px; display: block; }
.topbar .brand { flex-direction: row; align-items: center; gap: var(--s-3); }
.topbar .brand .logo { width: 31px; height: 31px; margin: 0; }

/* the family bubble: liquid glass just below the logo, its left edge on the logo's own left grid line */
.brand .logo-wrap { position: relative; display: block; }
.family {
  position: absolute; left: 1px; top: calc(100% - 7px + var(--bubble-gap)); z-index: 30; width: 220px;   /* 1px / 7px: where the logo's grid sits inside its viewBox */
  padding: 8px; border-radius: var(--bubble-radius); overflow: hidden;
  background: var(--bubble-fallback);
  box-shadow: inset 0 0 0 1px var(--bubble-rim), 0 0 0 0.5px var(--bubble-edge), var(--bubble-shadow);
  transform-origin: 0 0; transform: scale(0.85) translateY(-8px); opacity: 0;
  transition: transform var(--bubble-anim) cubic-bezier(0.2, 0.8, 0.2, 1), opacity var(--bubble-anim);
  text-transform: none; letter-spacing: 0; font-weight: 400;
}
.family::before { content: ''; position: absolute; inset: 0; border-radius: inherit; background: var(--bubble-sheen); pointer-events: none; }
.family > * { position: relative; }
@supports ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .family { background: var(--bubble-bg); -webkit-backdrop-filter: blur(var(--bubble-blur)) saturate(var(--bubble-saturate)); backdrop-filter: blur(var(--bubble-blur)) saturate(var(--bubble-saturate)); }
}
.family.open { transform: none; opacity: 1; }
.topbar .family { left: 5px; top: calc(100% - 5px + var(--bubble-gap)); }
.family-title { font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-2); padding: 6px 12px; }
.family-item {
  display: flex; align-items: center; gap: 12px; padding: 8px 10px; border-radius: var(--bubble-row-radius);
  color: var(--ink); text-decoration: none; transition: background 120ms;
}
.family-item:hover, .family-item:focus-visible { background: rgba(255, 255, 255, 0.5); box-shadow: inset 0 0 0 0.5px var(--bubble-rim); outline: none; }
.family-item.next { color: var(--ink-3); cursor: default; }
.family-item.next .family-tile { color: var(--ink-3); background: transparent; box-shadow: inset 0 0 0 0.5px var(--bubble-rim); }
.family-item.next:hover { background: transparent; box-shadow: none; }
.family-tile {
  flex: none; width: 40px; height: 40px; border-radius: var(--bubble-tile-radius); color: var(--app-accent);
  background: rgba(255, 255, 255, 0.6); box-shadow: inset 0 0 0 0.5px var(--bubble-rim), 0 1px 3px rgba(0, 0, 0, 0.06);
  display: flex; align-items: center; justify-content: center;
}
.family-tile svg { width: 26px; height: 26px; display: block; }
.family-name { font-size: 12px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; }
.brand small { display: block; font-size: 10px; font-weight: 500; letter-spacing: 0.08em; color: var(--ink-3); margin-top: 4px; text-transform: none; }
.curriculum { flex: 1; padding: 0 var(--s-3) var(--s-4); }
.track { margin-bottom: var(--s-2); }
.track-head {
  display: flex; align-items: center; gap: var(--s-2); width: 100%;
  padding: var(--s-2) var(--s-2); border: 0; background: none; cursor: pointer; text-align: left;
}
.track-head:hover .name { color: var(--ink); }
.track-head .num { font-family: var(--font-mono); font-size: 10px; color: var(--ink-3); width: 1.4em; }
.track-head .name { flex: 1; font-size: 10px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-2); }
.track-head .bar { width: 36px; height: 2px; background: var(--line); overflow: hidden; }
.track-head .bar i { display: block; height: 100%; background: var(--accent); width: 0; transition: width 300ms; }
.track-head .chev { color: var(--ink-3); transition: transform 150ms; font-size: 8px; }
.track.open .track-head .chev { transform: rotate(90deg); }
.lessons { list-style: none; margin: 0; padding: 0 0 var(--s-2) calc(1.4em + var(--s-2) + var(--s-2)); display: none; }
.track.open .lessons { display: block; }
.lesson-link {
  display: flex; align-items: center; gap: var(--s-2);
  padding: 5px var(--s-2); text-decoration: none; font-size: var(--fs-1); color: var(--ink-2);
}
.lesson-link:hover { color: var(--ink); }
.lesson-link.current { color: var(--accent); font-weight: 600; }
.lesson-link.planned { color: var(--ink-3); pointer-events: none; }
.lesson-link .tick { width: 12px; height: 12px; border-radius: 50%; border: 1px solid var(--line-2); flex: none; display: grid; place-items: center; }
.lesson-link.done .tick { background: var(--accent); border-color: var(--accent); }
.lesson-link.done .tick::after { content: ""; width: 4px; height: 7px; border: solid #fff; border-width: 0 1.5px 1.5px 0; transform: translateY(-1px) rotate(45deg); }
.lesson-link.started .tick { border-color: var(--accent); background: linear-gradient(90deg, var(--accent) 50%, transparent 50%); }
.lesson-link .soon { margin-left: auto; font-size: 9px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-3); }
.sidebar-footer { padding: var(--s-4) var(--s-5) var(--s-5); border-top: 1px solid var(--line); }
.sidebar-tools { display: flex; align-items: center; justify-content: space-between; gap: var(--s-2); margin-top: var(--s-3); }

.main { padding: var(--s-8) var(--s-7); min-width: 0; }
.page { max-width: var(--page-w); margin: 0; }
.prose { max-width: var(--measure); }
/* lesson body: text keeps the reading measure, boards and game viewers may use the full page width; everything centred */
.lesson-body { max-width: none; }
.lesson-body > :not(figure):not(.blk) { max-width: var(--measure); }
.topbar { display: none; }
.scrim { display: none; }

/* ---------- home ---------- */
.hero { max-width: var(--measure); margin: 0 0 var(--s-7); }
.hero h1 { margin: var(--s-3) 0 var(--s-4); }
.hero p { font-size: var(--fs-2); color: var(--ink-2); }
.hero-cite { font-size: 11px; letter-spacing: 0.06em; color: var(--ink-3); margin: calc(-1 * var(--s-3)) 0 var(--s-4); }
.hero-cite cite { font-style: italic; }
.hero-cite a { color: inherit; }
.card { border: 1px solid var(--line); padding: var(--s-5); background: var(--surface); }
.continue { display: flex; align-items: center; justify-content: space-between; gap: var(--s-4); margin-bottom: var(--s-6); }
.continue h3 { margin: var(--s-1) 0 0; }
.track-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: var(--s-4); }
.track-card { text-decoration: none; display: flex; flex-direction: column; gap: var(--s-2); min-height: 140px; transition: border-color 150ms; }
.track-card:hover { border-color: var(--accent); }
.track-card h3 { margin: 0; }
.track-card p { color: var(--ink-2); font-size: var(--fs-1); margin: 0; flex: 1; }
.track-card .meta { font-size: 10px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-3); }
.switch-row { display: flex; align-items: center; gap: var(--s-3); margin: var(--s-6) 0 var(--s-4); font-size: var(--fs-1); color: var(--ink-2); }
.switch { position: relative; width: 34px; height: 18px; border-radius: 9px; background: var(--line-2); border: 0; cursor: pointer; padding: 0; transition: background 150ms; }
.switch::after { content: ""; position: absolute; top: 2px; left: 2px; width: 14px; height: 14px; border-radius: 50%; background: #fff; transition: transform 150ms; }
.switch[aria-checked="true"] { background: var(--accent); }
.switch[aria-checked="true"]::after { transform: translateX(16px); }

/* ---------- lesson ---------- */
.lesson-head { margin: 0 0 var(--s-6); max-width: var(--measure); padding-bottom: var(--s-5); border-bottom: 1px solid var(--line); }
.lesson-head h1 { margin: var(--s-3) 0 var(--s-3); }
.lesson-head .lede { font-size: var(--fs-2); color: var(--ink-2); margin: 0; }
.lesson-nav { display: flex; justify-content: space-between; gap: var(--s-4); margin-top: var(--s-8); padding-top: var(--s-5); border-top: 1px solid var(--line); font-size: var(--fs-1); }
.lesson-nav a { text-decoration: none; color: var(--ink-2); }
.lesson-nav a:hover { color: var(--ink); }
.lesson-nav .next { text-align: right; }
.lesson-nav .eyebrow { display: block; margin-bottom: 2px; }
.complete-row { display: flex; align-items: center; gap: var(--s-4); margin-top: var(--s-7); padding: var(--s-4) 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); font-size: var(--fs-1); }
.complete-row .msg { color: var(--ink-2); }
.complete-row.done .msg { color: var(--accent); font-weight: 600; }
.complete-row .count { font-family: var(--font-mono); color: var(--ink-3); }
.sources { margin: var(--s-7) 0 0; padding-top: var(--s-5); border-top: 1px solid var(--line); font-size: var(--fs-0); color: var(--ink-2); max-width: var(--measure); }
.sources ul { padding-left: 1.2em; }
.sources li { margin-bottom: var(--s-2); overflow-wrap: anywhere; }
.callout { border-left: 1px solid var(--ink); padding: var(--s-2) var(--s-4); margin: var(--s-5) 0; max-width: var(--measure); }
.callout p:last-child { margin: 0; }
details.more { border-top: 1px solid var(--line); margin: var(--s-5) 0; }
details.more:last-of-type { border-bottom: 1px solid var(--line); }
details.more > summary { list-style: none; cursor: pointer; display: flex; align-items: center; gap: var(--s-3); padding: var(--s-4) 0; font-size: 10px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-2); }
details.more > summary::-webkit-details-marker { display: none; }
details.more > summary::before { content: "+"; width: 18px; height: 18px; border: 1px solid var(--line-2); display: grid; place-items: center; font-weight: 400; color: var(--ink-3); flex: none; font-size: 12px; }
details.more[open] > summary::before { content: "–"; border-color: var(--accent); color: var(--accent); }
details.more > summary:hover { color: var(--accent); }
details.more > .more-body { padding-bottom: var(--s-4); }
.puzzle-intro { font-size: var(--fs-1); color: var(--ink-2); margin: var(--s-6) 0 var(--s-3); }


/* ---------- board: full square, no decoration ---------- */
.board-wrap { width: 100%; max-width: var(--board-max); aspect-ratio: 1; position: relative; min-width: 0; margin: 0; }
.board-wrap[style*="--board-size:9"], .board-wrap[style*="--board-size: 9"] { max-width: min(var(--board-max), 420px); }
.board-wrap[style*="--board-size:13"], .board-wrap[style*="--board-size: 13"] { max-width: min(var(--board-max), 480px); }
.board-figure { margin: var(--s-5) 0 var(--s-6); }
.board-figure.with-aside { display: grid; grid-template-columns: min(var(--board-max), 58%) minmax(0, 1fr); gap: var(--s-6); align-items: end; }
.board-figure.with-aside figcaption { grid-column: 1; }
.board-aside { grid-column: 2; grid-row: 1; align-self: end; }
.board-aside .photo { position: relative; max-width: 240px; background: #f3efe6; padding: 6px; border: 1px solid var(--line); overflow: hidden; }
/* old film: warm monochrome, lifted blacks, soft contrast, grain and a light vignette */
.board-aside img { display: block; width: 100%; aspect-ratio: 4 / 5; object-fit: cover; filter: grayscale(1) sepia(0.32) contrast(0.9) brightness(1.04); }
.board-aside .photo::before { content: ""; position: absolute; inset: 6px; pointer-events: none; background: radial-gradient(ellipse at 50% 45%, rgba(0,0,0,0) 52%, rgba(40,30,15,0.38) 100%); mix-blend-mode: multiply; }
.board-aside .photo::after { content: ""; position: absolute; inset: 6px; pointer-events: none; opacity: 0.35; mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3CfeComponentTransfer%3E%3CfeFuncA type='table' tableValues='0 0.9'/%3E%3C/feComponentTransfer%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E"); }
.board-aside .photo.faded img { filter: grayscale(1) sepia(0.32) contrast(1.35) brightness(0.98); }
.board-aside .photo.dark img { filter: grayscale(1) sepia(0.32) contrast(0.85) brightness(1.15); }
.board-aside .credit { font-size: 10px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-3); margin-top: var(--s-2); max-width: 260px; }
@media (max-width: 900px) { .board-figure.with-aside { grid-template-columns: minmax(0, 1fr); } .board-aside { grid-column: 1; grid-row: auto; } }
.board-figure figcaption { font-size: var(--fs-1); color: var(--ink-2); margin: var(--s-3) 0 0; max-width: var(--board-max); }

/* the goban itself (js/goban.js draws it as SVG; everything visual is here) */
svg.goban { display: block; width: 100%; height: 100%; user-select: none; -webkit-user-select: none; touch-action: manipulation; }
.goban .wood { fill: var(--gb-wood); }
.goban .grid line { stroke: var(--gb-line); stroke-width: var(--gb-line-w); }
.goban .grid .star { fill: var(--gb-star); }
.goban .coords text { font-family: var(--font-sans); font-size: 10px; font-weight: 500; fill: var(--gb-coord); }
.goban .stone { transform-box: fill-box; transform-origin: center; }
.goban .stone.black { fill: var(--stone-black); stroke: var(--stone-black-edge); stroke-width: 0.6; filter: drop-shadow(0.6px 1px 0.8px var(--stone-shadow)); }
.goban .stone.white { fill: var(--stone-white); stroke: var(--stone-white-edge); stroke-width: 0.6; filter: drop-shadow(0.6px 1px 0.8px var(--stone-shadow)); }
.goban .stone.appear { animation: stone-appear var(--board-anim) ease-out; }
@keyframes stone-appear { from { transform: scale(0.72); opacity: 0.4 } to { transform: scale(1); opacity: 1 } }
.goban .stone.captured { animation: stone-capture calc(var(--board-anim) * 1.4) ease-in forwards; }
@keyframes stone-capture { to { transform: scale(0.6); opacity: 0 } }
.goban .stone.shake { animation: stone-shake 380ms ease-in-out; }
@keyframes stone-shake { 0%,100% { translate: 0 0 } 20% { translate: -4px 0 } 40% { translate: 4px 0 } 60% { translate: -3px 0 } 80% { translate: 3px 0 } }
.goban .ghost { pointer-events: none; opacity: var(--gb-ghost); }
.goban .ghost.black { fill: var(--stone-black); }
.goban .ghost.white { fill: var(--stone-white); stroke: var(--stone-white-edge); stroke-width: 0.6; }
.goban .hit { cursor: default; }
.goban.interactive .hit { cursor: pointer; }
.goban .marks * { pointer-events: none; }
.goban .mk-last { fill: none; stroke-width: 2; }
.goban .mk-last.on-black { stroke: var(--gb-last-on-black); }
.goban .mk-last.on-white { stroke: var(--gb-last-on-white); }
.goban .mk-hint { fill: var(--gb-hint); }
.goban .mk-good { fill: none; stroke: var(--gb-mark-good); stroke-width: 2.4; }
.goban .mk-bad { fill: none; stroke: var(--gb-mark-bad); stroke-width: 2.4; }
.goban .mk-tri, .goban .mk-sq { fill: none; stroke-width: 1.8; stroke: var(--gb-line); }
.goban .mk-x { fill: none; stroke-width: 2; stroke: var(--gb-mark-bad); }
.goban .mk-tri.on-black, .goban .mk-sq.on-black, .goban .mk-x.on-black { stroke: var(--gb-last-on-black); }
.goban .mk-tri.on-white, .goban .mk-sq.on-white { stroke: var(--gb-last-on-white); }
.goban .label-bg { fill: var(--gb-wood); }
.goban .label { font-family: var(--font-sans); font-size: 13px; font-weight: 600; fill: var(--gb-line); }
.goban .label.on-black { fill: var(--gb-last-on-black); }
.goban .label.on-white { fill: var(--gb-last-on-white); }
.goban .terr.black { fill: var(--stone-black); opacity: 0.75; }
.goban .terr.white { fill: var(--stone-white); stroke: var(--stone-white-edge); stroke-width: 0.6; opacity: 0.9; }
.goban .illegal { fill: none; stroke: var(--bad); stroke-width: 2; animation: stone-capture 420ms ease-out forwards; }


/* ---------- review ---------- */
.nav-badge { margin-left: auto; font-size: 10px; font-weight: 700; letter-spacing: 0.04em; background: var(--accent); color: var(--accent-ink); border-radius: 2px; padding: 1px 5px; }
.review-bar { display: flex; align-items: center; gap: var(--s-3); margin: 0 0 var(--s-5); }
.review-bar[hidden] { display: none; }   /* display:flex would otherwise beat the browser's [hidden] rule */
.review-count { font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); white-space: nowrap; }
.review-progress { flex: 1; height: 2px; background: var(--line); }
.review-progress i { display: block; height: 100%; background: var(--accent); transition: width 200ms; }
.review-from { font-size: var(--fs-1); color: var(--ink-3); margin-bottom: var(--s-2); }
.review-from a { color: var(--ink-2); }
.review-next { margin-top: var(--s-4); }
.review-done { display: flex; align-items: center; justify-content: space-between; gap: var(--s-4); }
.review-done h3 { margin: var(--s-1) 0; }

/* ---------- game viewer / exercise ---------- */
.game, .exercise {
  display: grid; grid-template-columns: min(var(--board-max), 58%) minmax(0, 1fr);
  gap: var(--s-5); margin: var(--s-5) 0 var(--s-7); outline: none;
}
.game > *, .exercise > * { min-width: 0; }
.game:focus-visible .board-wrap, .exercise:focus-visible .board-wrap { outline: 1px solid var(--accent); outline-offset: 2px; }
.game-controls { display: flex; gap: 0; margin-top: var(--s-3); }
.game-controls .icon-btn { width: 36px; margin-right: -1px; }
.game-controls .spacer { flex: 1; }
.game-side { min-width: 0; display: flex; flex-direction: column; }
.game-head { padding-bottom: var(--s-3); border-bottom: 1px solid var(--line); margin-bottom: var(--s-3); }
.game-players { font-size: var(--fs-2); font-weight: 600; line-height: 1.3; }
.game-meta { font-size: 10px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-3); margin-top: 4px; }
.game-note { font-size: var(--fs-1); color: var(--ink-2); min-height: 3.2em; margin-bottom: var(--s-3); line-height: 1.5; }
.moves {
  display: flex; flex-wrap: wrap; gap: 2px 0; align-content: flex-start;
  font-family: var(--font-mono); font-size: 12px; max-height: 420px; overflow-y: auto; padding-right: var(--s-2);
}
.moves .mv { border: 0; background: none; padding: 2px 6px; cursor: pointer; font: inherit; width: calc((100% - 3.2em) / 2); text-align: left; }
.moves .mv:hover { background: var(--surface-2); }
.moves .mv.current { background: var(--accent); color: #fff; }
.moves .mv { width: calc(100% / 3); }
.moves .mv-comment { width: 100%; font-family: var(--font-sans); font-size: var(--fs-1); color: var(--ink-2); padding: var(--s-2) 0 var(--s-2) 0.4em; line-height: 1.45; }
.moves .mv-break { width: 100%; height: 0; }
.moves .mv-result { width: 100%; color: var(--ink-3); padding: var(--s-2) 0 0 0.4em; }
.moves .mv-alt { padding-top: 0; padding-bottom: var(--s-1); color: var(--ink-3); }
.mv-vars .mv-var, .game-vars .mv-var { font: inherit; }
.moves .mv-var { border: 0; background: none; padding: 0 2px; cursor: pointer; color: var(--accent); text-decoration: underline; text-underline-offset: 2px; }
.game-vars { display: flex; flex-wrap: wrap; align-items: center; gap: var(--s-2); margin-bottom: var(--s-3); }
.game-vars-label { font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); margin-right: var(--s-1); }
.game-vars .mv-var.chosen { border-color: var(--accent); color: var(--accent); }

.exercise-side { display: flex; flex-direction: column; gap: var(--s-3); }
.exercise-side .turn { display: flex; align-items: center; gap: var(--s-2); font-size: 10px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-2); }
.turn-dot { width: 10px; height: 10px; border-radius: 50%; border: 1px solid var(--ink); background: #fff; }
.turn-dot.b { background: var(--ink); }
.turn-dot { display: inline-block; vertical-align: -1px; }
.game-caps { display: flex; align-items: center; gap: 6px; font-size: 12px; font-family: var(--font-mono); color: var(--ink-2); }
.moves .mv .mvdot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; border: 1px solid var(--ink); margin-right: 5px; vertical-align: 0; background: #fff; }
.moves .mv.b .mvdot { background: var(--ink); }
.moves .mv.current .mvdot { border-color: #fff; }
.moves .mv.current.w .mvdot { background: #fff; }
.exercise-side .prompt { font-size: var(--fs-2); }
.exercise-side .status { min-height: 1.6em; font-size: var(--fs-1); color: var(--ink-2); }
.exercise-side .status.good { color: var(--good); }
.exercise-side .status.bad { color: var(--bad); }
.exercise-side .hint { font-size: var(--fs-1); color: var(--ink-2); font-style: italic; }
.exercise-side .actions { display: flex; gap: var(--s-2); flex-wrap: wrap; margin-top: auto; }
.exercise.solved .board-wrap { outline: 2px solid var(--good); outline-offset: 0; }

/* ---------- prose tables ---------- */
.lesson-body table { border-collapse: collapse; margin: var(--s-4) 0; font-size: var(--fs-1); }
.lesson-body th, .lesson-body td { text-align: left; padding: 6px 18px 6px 0; border-bottom: 1px solid var(--line); }
.lesson-body th { font-size: 10px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); }
.lesson-body td:last-child, .lesson-body th:last-child { font-family: var(--font-mono); }


/* ---------- play page ---------- */
.nav-play { display: flex; align-items: center; gap: var(--s-2); padding: var(--s-2); margin-bottom: var(--s-3); text-decoration: none; border-bottom: 1px solid var(--line); }
.nav-play .num { font-size: 9px; color: var(--ink-3); width: 1.4em; }
.nav-play .name { font-size: 10px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-2); }
.nav-play:hover .name, .nav-play.current .name { color: var(--accent); }
.play { display: grid; grid-template-columns: min(var(--board-max), 58%) minmax(0, 1fr); align-items: start; gap: var(--s-6); margin: var(--s-5) 0 var(--s-7); }
.play > * { min-width: 0; }
.play-left { min-width: 0; }
.play-left .game-controls { max-width: var(--board-max); gap: var(--s-2); }
.play-side { display: flex; flex-direction: column; gap: var(--s-4); }
.play-side .turn { display: flex; align-items: center; gap: var(--s-2); font-size: 10px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-2); }
.field { display: flex; flex-direction: column; gap: 6px; }
.field label { font-size: 10px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); }
.seg { display: flex; }
.seg .btn { margin-right: -1px; }
.seg-wrap { flex-wrap: wrap; row-gap: 4px; }
.opp-note:empty { display: none; }
.opp-note { max-width: 34em; }
.seg .btn.on { background: var(--accent); color: #fff; border-color: var(--accent); }
.play .status { min-height: 1.6em; font-size: var(--fs-1); color: var(--ink-2); }
.play .status.good { color: var(--good); font-weight: 600; }
.play .status.bad { color: var(--bad); }
.play .moves { max-height: 300px; }
.play .moves .mv { cursor: default; display: inline-block; }
.score { display: flex; flex-direction: column; gap: 4px; padding: var(--s-3) 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); font-size: var(--fs-1); }
.score[hidden] { display: none; }
.score-row { display: flex; align-items: center; gap: var(--s-2); }
.score-row b { font-family: var(--font-mono); font-size: 14px; }
.score-win { color: var(--accent); font-weight: 600; margin-top: 4px; }


/* ---------- activity grid ---------- */
.activity-grid { display: grid; grid-template-rows: repeat(7, 1fr); grid-auto-flow: column; gap: 3px; width: 100%; }
.activity-grid i { aspect-ratio: 1; background: var(--act-0); display: block; }
.activity-grid i.l1 { background: var(--act-1); } .activity-grid i.l2 { background: var(--act-2); }
.activity-grid i.l3 { background: var(--act-3); } .activity-grid i.l4 { background: var(--act-4); }
.activity-grid i.today { outline: 1px solid var(--accent); outline-offset: -1px; }
.activity-stats { display: flex; justify-content: space-between; margin-top: var(--s-2); font-size: 10px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-3); }
.activity-stats b { color: var(--accent); font-weight: 600; }


/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .game, .exercise, .play { grid-template-columns: minmax(0, 1fr); }
  .moves { max-height: 260px; }
}
@media (max-width: 760px) {
  .app { grid-template-columns: minmax(0, 1fr); }
  .sidebar { position: fixed; inset: 0 auto 0 0; width: min(var(--sidebar-w), 86vw); transform: translateX(-100%); transition: transform 200ms; z-index: 20; box-shadow: 0 0 40px rgba(0,0,0,0.12); }
  .sidebar.open { transform: translateX(0); }
  .scrim { position: fixed; inset: 0; background: rgba(0,0,0,0.25); z-index: 15; display: none; }
  .scrim.open { display: block; }
  .topbar { display: flex; align-items: center; gap: var(--s-3); padding: var(--s-3) var(--s-4); border-bottom: 1px solid var(--line); background: var(--surface); position: sticky; top: 0; z-index: 10; }
  .topbar .brand { padding: 0; }
  .main { padding: var(--s-5) var(--s-4) var(--s-8); }
  h1 { font-size: var(--fs-3); }

  /* phones: thumbs, not pointers — taller buttons, and the words above the board so that feedback is visible while tapping */
  .btn, .icon-btn { min-height: 40px; }
  .game-controls .icon-btn { width: 44px; height: 44px; }
  .exercise { gap: var(--s-3); }
  .exercise-side { display: contents; }
  .exercise-side .turn { order: -3; }
  .exercise-side .prompt { order: -2; }
  .exercise-side .status { order: -1; min-height: 1.6em; }
  .exercise-board { order: 0; margin-bottom: var(--s-2); }
  .exercise-side .hint { order: 1; }
  .exercise-side .actions { order: 2; }
  .play { gap: var(--s-4); }
  .play-side { display: contents; }
  .play-side .turn { order: -2; }
  .play-side .status { order: -1; }
  .play-left { order: 0; }
  .play-side .field, .play-side .caps, .play-side .score, .play-side .play-moves { order: 1; }
  .play-side .score { order: 0; }
  .moves .mv { width: calc(100% / 3); min-height: 32px; }
  .moves { max-height: 240px; }
}
@media (prefers-reduced-motion: reduce) {
  .goban .stone.appear, .goban .stone.shake { animation: none; }
  .family { transition: none; }
  .switch::after, .track-head .bar i { transition: none; }
}
.sidebar-footer .credit { margin-top: var(--s-3); font-size: 10px; line-height: 1.5; color: var(--ink-3); }
.sidebar-footer .credit b { font-weight: 600; color: var(--ink-2); }
.sidebar-footer .credit a { color: var(--ink-3); text-decoration: none; }
.sidebar-footer .credit a:hover { color: var(--accent); }
/* cmx-20260927-c91973c7d47b */

/* ---------- the cat in the box (js/mascot.js) ---------- */
/* Always in the corner, small. It meows when it has something and waits to be clicked; the bubble only
   opens on a click. Clicked with nothing to say, it answers with hearts. */
.mascot {
  position: fixed; right: max(14px, env(safe-area-inset-right)); bottom: max(8px, env(safe-area-inset-bottom)); z-index: 60;
  display: flex; flex-direction: column; align-items: flex-end;
  pointer-events: none;
}
.mascot > * { pointer-events: auto; }
.mascot[hidden] { display: none; }
.mascot-live { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* the bubble: only there when opened */
.mascot-bubble {
  position: relative; box-sizing: border-box;
  width: max-content; max-width: min(232px, calc(100vw - 28px));
  padding: 8px 24px 9px 11px;
  margin: 0 0 calc(var(--mascot-tail) * 1px + 3px) 0;
  transform-origin: 70% 100%; transform: scale(.6); opacity: 0; visibility: hidden;
  transition: transform 240ms cubic-bezier(.2, 1.4, .4, 1), opacity 140ms, visibility 0s 240ms;
}
.mascot[data-state="open"] .mascot-bubble { transform: scale(1); opacity: 1; visibility: visible; transition: transform 240ms cubic-bezier(.2, 1.4, .4, 1), opacity 140ms, visibility 0s; }
.mascot-outline { position: absolute; left: 0; top: 0; overflow: visible; pointer-events: none; }
.mascot-outline path {
  fill: var(--mascot-paper); stroke: var(--mascot-line); stroke-width: calc(var(--mascot-stroke) * 1px);
  stroke-linejoin: round; stroke-linecap: round;
}
.mascot-label, .mascot-text, .mascot-close { position: relative; }
.mascot-label { display: block; font-size: 9px; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; margin-bottom: 2px; color: var(--mascot-tip); }
.mascot[data-kind="hint"] .mascot-label { color: var(--mascot-hint); }
.mascot-text { margin: 0; font-size: 12.5px; line-height: 1.42; color: var(--ink); }
.mascot-text b { font-weight: 700; }
.mascot-close {
  position: absolute; top: 3px; right: 4px; width: 20px; height: 20px; padding: 0;
  border: 0; background: none; color: var(--ink-3); font-size: 16px; line-height: 1; cursor: pointer;
}
.mascot-close:hover { color: var(--ink); }

/* the cat, its meow, its hearts */
.mascot-body { position: relative; }
.mascot-cat {
  display: block; width: var(--mascot-cat-w); padding: 0; margin: 0; border: 0; background: none; cursor: pointer;
  transform-origin: 50% 100%; transition: transform 160ms;
}
.mascot-cat:hover { transform: translateY(-2px); }
.mascot-cat:focus-visible { outline: 1px solid var(--accent); outline-offset: 3px; border-radius: 6px; }
.mascot-cat svg { display: block; width: 100%; height: auto; filter: drop-shadow(0 2px 2px rgba(0, 0, 0, 0.10)); }
.mascot-cat.squish { animation: mascot-squish 260ms ease-out; }
.mascot-body.hop { animation: mascot-hop 700ms cubic-bezier(.3, 0, .3, 1); }

/* "meow" — a word and three sound lines beside the head, drawn in the artwork's black */
.mascot-meow {
  position: absolute; right: 64%; bottom: 72%;
  display: flex; align-items: flex-end; gap: 1px;
  font-size: 10.5px; font-weight: 700; letter-spacing: 0.03em; color: var(--mascot-ink);
  opacity: 0; transform: scale(.4) rotate(-8deg); transform-origin: 100% 100%;
  transition: opacity 160ms, transform 240ms cubic-bezier(.2, 1.5, .4, 1);
  pointer-events: none;
}
.mascot-meow span { transform: rotate(-8deg); }
.mascot-sound { width: 13px; height: 13px; order: 2; margin-bottom: 7px; }
.mascot-sound path { fill: none; stroke: var(--mascot-ink); stroke-width: 1.6; stroke-linecap: round; }
.mascot[data-state="meowing"] .mascot-meow { opacity: 1; transform: scale(1) rotate(-8deg); animation: mascot-meow 1.6s ease-in-out 400ms infinite; }

.mascot-hearts { position: absolute; left: 40%; top: 6%; width: 0; height: 0; pointer-events: none; }
.mascot-hearts .heart {
  position: absolute; left: calc(var(--size) / -2); top: 0; width: var(--size); height: var(--size);
  animation: mascot-heart 1.1s ease-out var(--delay) both;
}
.mascot-hearts svg { display: block; width: 100%; height: 100%; overflow: visible; }
.mascot-hearts path { fill: var(--mascot-heart); stroke: var(--mascot-ink); stroke-width: 1.8; stroke-linejoin: round; }

@keyframes mascot-hop { 0%, 100% { transform: translateY(0) } 28% { transform: translateY(-9px) } 50% { transform: translateY(0) } 68% { transform: translateY(-3px) } }
@keyframes mascot-squish { 0% { transform: scale(1, 1) } 35% { transform: scale(1.07, .9) } 70% { transform: scale(.97, 1.04) } 100% { transform: scale(1, 1) } }
@keyframes mascot-meow { 0%, 100% { transform: scale(1) rotate(-8deg) } 50% { transform: scale(1.1) rotate(-5deg) } }
@keyframes mascot-heart {
  0% { transform: translate(0, 0) scale(.3); opacity: 0 }
  18% { transform: translate(calc(var(--dx) * .3), -8px) scale(1); opacity: 1 }
  100% { transform: translate(var(--dx), -58px) scale(.85); opacity: 0 }
}

@media (max-width: 560px) {
  .mascot { right: max(10px, env(safe-area-inset-right)); }
  .mascot-cat { width: var(--mascot-cat-w-phone); }
  .mascot-bubble { max-width: calc(100vw - 20px); }
}
@media (prefers-reduced-motion: reduce) {
  .mascot-bubble, .mascot[data-state="open"] .mascot-bubble { transform: none; transition: opacity 140ms, visibility 0s; }
  .mascot-cat.squish, .mascot-body.hop, .mascot[data-state="meowing"] .mascot-meow { animation: none; }
  .mascot-meow { transform: rotate(-8deg); }
  .mascot-hearts .heart { animation: mascot-heart-still 1.1s ease-out var(--delay) both; }
  @keyframes mascot-heart-still { 0% { opacity: 0 } 25% { opacity: 1 } 100% { opacity: 0; transform: translate(var(--dx), -20px) } }
}

/* a tip tucked into a lesson: a small cat and a label in the text; the cat in the corner delivers it */
.prose .tip { margin: var(--s-4) 0; }
.prose .tip-cue {
  display: inline-flex; align-items: center; gap: 9px; padding: 3px 12px 3px 4px;
  border: 1px solid var(--line-2); border-radius: 999px; background: var(--bg); cursor: pointer;
  font: inherit; font-size: 11px; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-2);
}
.prose .tip-cue:hover { border-color: var(--accent); color: var(--accent); }
.prose .tip-cat { display: block; }
.prose .tip-text { margin: var(--s-2) 0 0; padding-left: var(--s-3); border-left: 2px solid var(--line-2); font-size: var(--fs-1); color: var(--ink-2); }

/* the switch for the cat, beside the mute button */
.icon-btn.cat-toggle { width: 32px; }
.icon-btn.cat-toggle .tip-cat { width: 24px; height: auto; }
.icon-btn.cat-toggle[aria-pressed="false"] { opacity: 0.4; }

/* the welcome's background on this app only: a 16-bit goban replaying the ear-reddening game (js/pixel-go.js) */
.wl-pixel { position: absolute; inset: 0; width: 100%; height: 100%; z-index: -1; pointer-events: none; image-rendering: pixelated; }
.wl-pixel-grid { fill: var(--wl-ink); opacity: .16; }
.wl-pixel-stones .b { fill: #1a0405; opacity: .55; }
.wl-pixel-stones .bh { fill: var(--wl-ink); opacity: .35; }
.wl-pixel-stones .w { fill: var(--wl-ink); opacity: .5; }
.wl-pixel-stones .wh { fill: var(--wl-ink); opacity: .25; }
.wl-pixel-cursor { fill: var(--wl-ink); opacity: .9; }