:root {
    --page: #0b0d10;
    --surface: #15191f;
    --raised: #1c2129;
    --text: #f3f4f6;
    --muted: #a6aebb;
    --line: #303943;
    --accent: #00d289;
    --mint: #86dec1;
    --danger: #ffaca1;
    --heading: 'Manrope', 'Trebuchet MS', sans-serif;
    --body: 'Trebuchet MS', sans-serif;
    --mono: Consolas, 'Courier New', monospace;
    color-scheme: dark;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; background: var(--page); color: var(--text); font-family: var(--body); line-height: 1.6; }
body::before { content: ''; position: fixed; inset: 0; z-index: -1; pointer-events: none; background: radial-gradient(ellipse at 90% 10%, #00d2890d, transparent 50%), repeating-linear-gradient(90deg, transparent 0 79px, #ffffff03 79px 80px); }
a { color: inherit; text-decoration: none; }
button, input, select { font: inherit; }
button, .button { cursor: pointer; }
button { color: inherit; }
button:disabled { cursor: default; opacity: .5; }
button, a, input, select { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
h1, h2, h3, p { margin: 0; }
h1, h2, h3 { font-family: var(--heading); line-height: 1.12; }
.skip-link { position: fixed; left: 16px; top: -100px; z-index: 100; background: var(--accent); color: var(--page); padding: 12px; }
.skip-link:focus { top: 10px; }
.site-header { border-bottom: 1px solid var(--line); background: var(--page); position: sticky; top: 0; z-index: 30; }
.header-inner { max-width: 1240px; margin: auto; min-height: 86px; display: flex; justify-content: space-between; align-items: center; gap: 20px; padding: 16px 28px; }
.brand { font: 700 26px var(--heading); display: flex; align-items: center; gap: 10px; letter-spacing: -1px; }
.brand-mark { display: inline-flex; align-items: center; justify-content: center; width: 40px; height: 40px; background: var(--accent); color: var(--page); border-radius: 10px; font: italic 700 34px Georgia, serif; }
.brand-mark span { font: 700 22px var(--mono); margin: 8px 0 0 -2px; }
.version { font: 11px var(--mono); color: var(--muted); letter-spacing: 0; }
.site-header nav { display: flex; gap: 20px; font-size: 14px; align-items: center; }
.site-header nav a:hover, .back-link:hover, footer a:hover { color: var(--accent); }
.main-link { border: 1px solid var(--accent); padding: 9px 15px; border-radius: 7px; color: var(--accent); font-weight: 700; }
.main-link:hover { background: #00d28918; }
.page { max-width: 1240px; padding: 0 28px 64px; margin: auto; }
.hero { display: grid; grid-template-columns: 1.35fr 1fr; gap: 64px; align-items: center; padding: 76px 0 66px; }
.eyebrow { font: 11px var(--mono); letter-spacing: 1.7px; color: var(--mint); text-transform: uppercase; }
.status-dot { display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: var(--mint); margin-right: 7px; }
.hero h1 { font-size: clamp(36px, 4.4vw, 56px); letter-spacing: -2.5px; margin: 21px 0; }
.hero h1 em { font-family: Georgia, serif; font-weight: 400; color: var(--accent); }
.hero-description { max-width: 500px; font-size: 16px; color: var(--muted); margin-bottom: 27px; }
.button, .primary, .secondary { border-radius: 7px; padding: 12px 22px; min-height: 46px; display: inline-flex; gap: 20px; justify-content: center; align-items: center; border: 1px solid var(--line); font-weight: 700; }
.primary { background: var(--accent); color: #07150e; border-color: var(--accent); }
.primary:hover:not(:disabled) { background: #3be5a9; }
.secondary { background: var(--raised); }
.secondary:hover:not(:disabled) { border-color: var(--mint); }
.hero-note { display: block; margin-top: 13px; color: var(--muted); font-size: 11px; }
.hero-art { background: #d5dfc4; color: #1c3528; min-height: 330px; padding: 26px 30px 20px; border-radius: 6px; transform: rotate(2deg); position: relative; overflow: hidden; box-shadow: 12px 12px 0 #34463a66; background-image: linear-gradient(#37563712 1px, transparent 1px), linear-gradient(90deg, #37563712 1px, transparent 1px); background-size: 24px 24px; }
.art-caption, .art-bottom { font: 10px var(--mono); letter-spacing: 1.5px; }
.art-equation { display: flex; align-items: center; justify-content: center; gap: 25px; font: 700 76px var(--mono); margin-top: 20px; }
.art-equation i { font: 400 56px Georgia, serif; color: #547459; }
.art-answer { display: flex; justify-content: center; align-items: center; gap: 20px; font: 60px var(--mono); margin: -10px 0 12px; }
.art-answer strong { font-weight: 400; border-bottom: 3px solid #476a4c; transform: rotate(-7deg); }
.art-star { color: #517458; font-size: 60px; position: absolute; right: 18px; bottom: 49px; }
.art-bottom { display: flex; justify-content: space-between; border-top: 1px solid #9aaf90; padding-top: 16px; }
.library-heading { border-top: 1px solid var(--line); padding-top: 32px; display: flex; justify-content: space-between; gap: 20px; align-items: center; }
.library-heading h2 { font-size: 30px; margin-top: 8px; letter-spacing: -.7px; }
.local-summary { font-size: 13px; color: var(--muted); text-align: right; }
.local-summary strong { color: var(--accent); font: 24px var(--mono); margin-right: 4px; }
.local-summary span { display: block; font-size: 11px; }
.filter-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 27px 0 25px; }
.filter { border: 1px solid var(--line); color: var(--muted); background: transparent; border-radius: 25px; padding: 8px 17px; font-size: 13px; min-height: 40px; }
.filter.active { color: var(--page); background: var(--mint); border-color: var(--mint); }
.filter span { font-family: var(--mono); font-size: 11px; margin-left: 5px; }
.game-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.game-card { display: flex; flex-direction: column; padding: 25px; background: linear-gradient(140deg, #ffffff06, transparent 70%), var(--surface); border: 1px solid var(--line); border-radius: 10px; min-width: 0; transition: transform .18s, border-color .18s; animation: reveal .45s both; animation-delay: calc(var(--i) * 35ms); }
.game-card:hover { transform: translateY(-4px); border-color: #809c76; }
.card-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: 22px; }
.game-symbol { display: inline-flex; align-items: center; justify-content: center; width: 49px; height: 49px; border: 1px solid #617152; color: var(--accent); border-radius: 12px; font: 23px var(--mono); background: #e7bd6209; }
.card-number { font: 11px var(--mono); color: #96aa97; }
.game-card .eyebrow { font-size: 9px; letter-spacing: 1px; }
.game-card h3 { font-size: 21px; letter-spacing: -.5px; margin: 8px 0 12px; }
.game-card p { color: var(--muted); font-size: 13px; flex: 1; }
.card-bottom { display: flex; justify-content: space-between; align-items: center; border-top: 1px solid var(--line); margin-top: 24px; padding-top: 15px; }
.card-bottom span:first-child { font: 11px var(--mono); color: var(--muted); }
.card-bottom span:last-child { color: var(--accent); font-size: 13px; }
.practice-note { margin-top: 30px; border-left: 2px solid var(--mint); padding: 12px 20px; color: var(--muted); font-size: 12px; background: #93d9bc05; }
.practice-note strong { color: var(--text); }
.fastmath-footer { background: var(--surface); border-color: var(--line); font-family: var(--body); }
.fastmath-footer .st-footer-col p, .fastmath-footer .st-footer-col h3, .fastmath-footer .st-footer-nav a, .fastmath-footer .st-footer-bottom p { color: var(--muted); }
.fastmath-footer .st-company-name { display: inline-block; margin-bottom: 12px; }
.fastmath-footer .footer-privacy { margin: 15px 0; }
.fastmath-footer .st-footer-bottom > a { color: var(--accent); font-size: 12px; }
.text-button { padding: 0; background: none; border: 0; color: var(--muted); font-size: 12px; text-decoration: underline; text-underline-offset: 4px; }
.text-button:hover { color: var(--accent); }
.play-heading { display: flex; align-items: center; justify-content: space-between; gap: 15px; padding-top: 35px; }
.back-link { font-size: 14px; color: var(--muted); }
.play-title-row { display: flex; align-items: center; justify-content: space-between; gap: 18px; margin: 25px 0 30px; }
.play-title-row h1 { font-size: clamp(27px, 4vw, 42px); letter-spacing: -1px; }
#game-title:focus { outline: none; }
.play-title-row p { color: var(--muted); margin-top: 8px; font-size: 14px; }
.game-index { font: 32px var(--mono); color: #69806d; }
.play-layout { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 24px; align-items: start; }
.play-panel { border: 1px solid var(--line); border-radius: 12px; background: var(--surface); overflow: hidden; }
.panel-top { display: flex; justify-content: space-between; align-items: center; padding: 17px 24px; border-bottom: 1px solid var(--line); font: 10px var(--mono); letter-spacing: 1px; }
.controls { display: flex; align-items: end; flex-wrap: wrap; gap: 18px; padding: 22px 26px; background: #0b120e40; }
.controls label { color: var(--muted); font-size: 12px; display: grid; gap: 6px; flex: 1; min-width: 130px; }
.controls label.check { display: flex; align-items: center; gap: 10px; flex: 1 1 100%; }
input, select { padding: 9px 12px; border: 1px solid #576d5b; border-radius: 6px; background: #101b15; color: var(--text); min-height: 44px; min-width: 0; max-width: 100%; }
input[type="range"] { padding: 0; width: 100%; accent-color: var(--accent); }
input[type="checkbox"] { accent-color: var(--accent); min-height: auto; width: 18px; height: 18px; }
.controls output { float: right; font-family: var(--mono); color: var(--accent); }
.stage { min-height: 300px; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 20px; padding: 30px 26px; position: relative; text-align: center; }
.stage p { color: var(--muted); font-size: 14px; max-width: 500px; }
.stage .stage-label { font: 11px var(--mono); color: var(--mint); letter-spacing: 1px; text-transform: uppercase; }
.idle-symbol { font: 70px var(--mono); color: var(--accent); opacity: .8; }
.actions { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 12px; padding: 0 26px 28px; }
.answer-form { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; width: 100%; }
.answer-form label { flex-basis: 100%; font-size: 12px; color: var(--muted); }
.answer-form input { width: 180px; font: 22px var(--mono); text-align: center; }
.answer-form input.expression-input { width: min(100%, 390px); font-size: 19px; }
.feedback { margin: 0 26px 22px; padding: 14px 18px; border: 1px solid var(--line); border-radius: 7px; background: #10171480; font-size: 14px; overflow-wrap: anywhere; }
.feedback:empty { display: none; }
.feedback.good { color: var(--mint); border-color: #4d8267; }
.feedback.bad { color: var(--danger); border-color: #88554d; }
.feedback .result-stats { display: flex; flex-wrap: wrap; gap: 10px 25px; margin-top: 10px; font: 12px var(--mono); }
.game-sidebar { display: grid; gap: 16px; }
.side-card { padding: 23px; border: 1px solid var(--line); border-radius: 10px; }
.side-card h2 { font-size: 18px; margin: 12px 0; }
.side-card p:not(.eyebrow), .side-card li { font-size: 13px; color: var(--muted); }
.side-card .small { margin-top: 12px; font-size: 10px !important; }
.key-hint { margin-top: 16px; font-size: 11px; color: var(--accent); font-family: var(--mono); }
.record-item { padding: 10px 0; border-bottom: 1px solid var(--line); font-size: 12px; }
.record-item strong { display: block; color: var(--accent); font: 18px var(--mono); }
.record-item span { color: var(--muted); font-size: 10px; }
.dice-tray { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; width: 100%; }
.die { width: 66px; height: 66px; padding: 10px; display: grid; grid-template-columns: repeat(3, 1fr); grid-template-rows: repeat(3, 1fr); gap: 3px; background: #f3eedc; border-radius: 11px; box-shadow: 0 4px 0 #a9b7a0; transform: rotate(var(--tilt)); }
.pip { width: 100%; aspect-ratio: 1; border-radius: 50%; background: transparent; }
.pip.on { background: #19392a; }
.timer { font: 20px var(--mono); color: var(--accent); font-variant-numeric: tabular-nums; }
.spatial-grid { display: grid; gap: 8px; width: min(100%, 430px); }
.chimp-grid { grid-template-columns: repeat(var(--size), 1fr); gap: 6px; }
.spatial-cell { aspect-ratio: 1; border: 1px solid transparent; background: transparent; border-radius: 6px; display: flex; justify-content: center; align-items: center; font: clamp(16px, 3vw, 25px) var(--mono); padding: 0; min-width: 0; touch-action: manipulation; }
.spatial-cell.empty { pointer-events: none; }
.chimp-tile { background: #eef0df; color: #163a29; border-color: #e7ebd9; }
.chimp-tile.masked { color: transparent; }
.chimp-tile.cleared { opacity: 0; pointer-events: none; }
.chimp-tile.wrong { background: #ffaca1; color: #501810; }
.corsi-grid { grid-template-columns: repeat(3, 1fr); max-width: 330px; }
.corsi-tile { background: #2e4638; border-color: #66806a; opacity: 1 !important; }
.corsi-tile.lit { background: var(--accent); box-shadow: 0 0 25px #e7bd6244; color: #13261b; }
.giant-number { font: clamp(75px, 12vw, 130px) var(--mono); line-height: 1.15; color: var(--accent); min-height: 150px; display: flex; align-items: center; }
#prime-number { touch-action: pan-y; user-select: none; }
.progress { height: 4px; background: #34463a; width: 100%; border-radius: 3px; }
.progress > span { display: block; height: 100%; background: var(--mint); }
.source-numbers { display: flex; flex-wrap: wrap; gap: 9px; justify-content: center; }
.source-number { font: 26px var(--mono); padding: 9px 14px; border: 1px solid #617152; border-radius: 6px; color: var(--mint); background: #93d9bc09; }
.target-number { font: 62px var(--mono); color: var(--accent); line-height: 1.2; }
.comparison { display: grid; grid-template-columns: 1fr 38px 1fr; gap: 12px; align-items: center; width: 100%; }
.expression { padding: 25px 8px; background: #0d1710; border: 1px solid var(--line); border-radius: 10px; font: clamp(20px, 3vw, 32px) var(--mono); }
.comparison .versus { color: var(--muted); font: 13px var(--mono); }
.score-strip { width: 100%; display: flex; justify-content: space-between; gap: 8px; font: 13px var(--mono); color: var(--mint); }
.choice-row { display: flex; justify-content: center; flex-wrap: wrap; gap: 10px; }
.choice-row button { min-width: 90px; }
.operator-equation { font: clamp(20px, 3vw, 32px) var(--mono); display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 8px; }
.operator-slot { font: 22px var(--mono); width: 62px; padding: 8px 4px; text-align: center; border-style: dashed; border-color: var(--accent); }
.operator-slot.selected { outline: 2px solid var(--mint); outline-offset: 3px; }
.operator-bank button { font: 25px var(--mono); min-width: 52px; padding: 5px 15px; }
.matrix { border-collapse: collapse; width: min(100%, 350px); font: 24px var(--mono); }
.matrix th { font: 10px var(--body); color: var(--muted); padding-bottom: 10px; }
.matrix td { padding: 12px; border: 1px solid var(--line); }
.matrix td.missing { color: var(--accent); }
.number-line { width: 100%; position: relative; margin: 35px 0 35px; min-height: 54px; padding: 20px 0; cursor: crosshair; touch-action: pan-y; outline-offset: 8px; user-select: none; }
.number-line::before { content: ''; position: absolute; top: 26px; height: 3px; background: #e6e5d6; left: 0; right: 0; }
.line-end { position: absolute; top: 37px; font: 13px var(--mono); color: var(--muted); }
.line-end.left { left: 0; }
.line-end.right { right: 0; }
.line-marker { position: absolute; top: 14px; width: 3px; height: 27px; background: var(--accent); transform: translateX(-50%); }
.line-marker.exact { background: var(--mint); height: 42px; top: 7px; }
.line-marker::after { content: attr(data-label); position: absolute; top: -27px; transform: translateX(-50%); font: 13px var(--mono); color: var(--accent); white-space: nowrap; }
.line-marker.exact::after { top: 50px; color: var(--mint); }
.estimate-prompt { font: 34px var(--mono); color: var(--accent); }
.flash-number { font: clamp(50px, 10vw, 90px) var(--mono); color: var(--accent); min-height: 120px; }
.revealed-sequence { font: 15px var(--mono); color: var(--muted); overflow-wrap: anywhere; }
.live-message { min-height: 26px; font-size: 13px; color: var(--muted); }
@keyframes reveal { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
@media (max-width: 1000px) {
    .hero { gap: 35px; }
    .game-grid { grid-template-columns: repeat(2, 1fr); }
    .play-layout { grid-template-columns: minmax(0, 1fr) 240px; gap: 16px; }
}
@media (max-width: 760px) {
    .page { padding: 0 18px 40px; }
    .header-inner { padding: 14px 18px; min-height: 72px; }
    .brand { font-size: 23px; gap: 8px; }
    .site-header nav { gap: 13px; font-size: 12px; }
    .brand .version { display: none; }
    .hero { padding: 42px 0; grid-template-columns: 1fr; gap: 32px; }
    .hero h1 { font-size: 43px; letter-spacing: -1.7px; }
    .hero-art { min-height: 270px; width: min(100% - 12px, 450px); justify-self: center; }
    .art-equation { font-size: 66px; margin-top: 9px; }
    .art-answer { font-size: 53px; }
    .library-heading { align-items: start; }
    .library-heading h2 { font-size: 25px; }
    .local-summary { max-width: 110px; font-size: 11px; }
    .game-card { padding: 20px; }
    .play-layout { grid-template-columns: 1fr; }
    .game-sidebar { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .records { grid-column: 1 / -1; }
    .play-heading .eyebrow { font-size: 9px; text-align: right; max-width: 190px; }
}
@media (max-width: 450px) {
    .header-inner { flex-wrap: wrap; gap: 12px; }
    .site-header nav { flex-basis: 100%; justify-content: space-between; }
    .game-grid { grid-template-columns: 1fr; gap: 12px; }
    .game-card { padding: 22px; }
    .card-top { margin-bottom: 16px; }
    .game-card h3 { font-size: 23px; }
    .stage { padding: 25px 16px; min-height: 270px; }
    .controls { padding: 18px 16px; gap: 12px; }
    .actions { padding: 0 16px 24px; }
    .feedback { margin: 0 16px 18px; }
    .play-title-row { align-items: start; }
    .game-index { font-size: 24px; }
    .game-sidebar { grid-template-columns: 1fr; }
    .die { width: 55px; height: 55px; padding: 8px; }
    .dice-tray { gap: 10px; }
    .comparison { gap: 5px; grid-template-columns: 1fr 22px 1fr; }
    .expression { font-size: 19px; padding: 23px 4px; }
    .choice-row button { min-width: 76px; padding: 11px 14px; }
    .operator-equation { gap: 5px; }
    .operator-slot { width: 53px; }
    .operator-result { flex-basis: 100%; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; } }