:root{color-scheme:dark;--bg:#131617;--panel:#1b1f20;--panel2:#222728;--line:#343a3b;--muted:#a3adae;--text:#f2f3ee;--orange:#ff9d59;--green:#b4d5ac;--font: 'NumBraid Sans', 'Segoe UI', sans-serif;--mono: 'Cascadia Code', 'SFMono-Regular', Consolas, monospace}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font);font-size:16px;line-height:1.55}button,input,select,textarea{font:inherit}button,a,input,select,textarea{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:default;opacity:.38}button,a,input,select,textarea{outline-offset:5px}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:2px solid var(--orange)}button{color:inherit}a{color:inherit}button{border:0}button:not(:disabled){transition:background .16s,transform .16s,border-color .16s}button:active:not(:disabled){transform:translateY(1px)}[hidden]{display:none!important}h1,h2,h3,p{margin:0}h1,h2{font-weight:600;line-height:1.15;letter-spacing:-.045em}.shell{max-width:1240px;margin:auto;padding:0 44px}.site-header{display:flex;align-items:center;justify-content:space-between;min-height:112px;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;text-decoration:none;font-size:28px;font-weight:700;letter-spacing:-1.2px}.brand>span:not(.brand-mark){font-weight:400;color:var(--orange)}.brand small{font-size:10px;letter-spacing:2px;line-height:1.7;max-width:126px;margin-left:25px;padding-left:25px;border-left:1px solid var(--line);font-weight:500;color:var(--muted)}.brand-mark{display:grid;grid-template-columns:9px 9px;gap:4px;margin-right:13px}.brand-mark i{width:9px;height:9px;background:var(--orange);border-radius:1px}.brand-mark i:last-child{transform:rotate(45deg)}.site-header nav{display:flex;align-items:center;gap:25px}.nav-button,.help-button{background:transparent}.nav-button{font-size:14px}.nav-button span{color:var(--muted);margin-left:9px}.help-button{border:1px solid #51595b;border-radius:50%;width:30px;height:30px;font-family:var(--mono)}.topline{display:flex;align-items:center;justify-content:space-between;margin-top:29px}.mode-switch{display:flex;border:1px solid var(--line);border-radius:8px;padding:4px;gap:3px;background:#191d1e}.mode-switch button{padding:8px 19px;background:transparent;border-radius:5px;color:var(--muted);font-size:14px}.mode-switch button[aria-pressed=true]{background:#353b3c;color:var(--text);box-shadow:0 1px 3px #0004}.date-label{font-size:13px;color:var(--muted)}.page-heading{display:flex;align-items:end;justify-content:space-between;gap:20px;margin:35px 0 26px}.eyebrow{font-size:11px;font-weight:600;letter-spacing:1.6px;color:var(--muted)}.live-dot{display:inline-block;width:6px;height:6px;background:var(--orange);border-radius:50%;margin-right:8px;vertical-align:middle}h1{font-size:38px;margin:10px 0 9px}.page-heading p{color:var(--muted);font-size:15px}.difficulty-label{display:flex;flex-direction:column;gap:6px;color:var(--muted);font-size:12px;flex-shrink:0}select{color:var(--text);background:var(--panel);border:1px solid #454d4e;border-radius:6px;padding:10px 34px 10px 13px;font-size:14px}.game-layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:25px}.puzzle-panel{background:var(--panel);border:1px solid var(--line);border-radius:13px;overflow:hidden}.board-top{display:flex;justify-content:space-between;align-items:center;padding:20px 26px;border-bottom:1px solid var(--line)}.board-label{font:11px var(--mono);letter-spacing:1.6px;color:var(--muted)}.board-label>span{color:var(--orange);font-size:18px;vertical-align:middle;margin-right:8px}.metrics{display:flex;gap:26px}.metrics>div{display:flex;flex-direction:column;text-align:right}.metrics span{font-size:9px;letter-spacing:1.2px;color:var(--muted)}.metrics strong{font:18px var(--mono);margin-top:3px}.target-area{position:relative;text-align:center;padding:30px 15px 25px;background-image:radial-gradient(#727b7b28 .8px,transparent .8px);background-size:16px 16px}.target-ring{display:flex;align-items:center;flex-direction:column}.target-ring .eyebrow{color:var(--orange);font-size:10px;letter-spacing:2px}.target-ring strong{font-size:100px;line-height:1.1;letter-spacing:-7px;font-weight:500;color:var(--orange);font-variant-numeric:tabular-nums;padding:2px 12px 3px 0}.target-caption{font-size:12px;color:var(--muted)}.target-corner{position:absolute;color:#5c6565;font:18px var(--mono);top:50%}.corner-a{left:33px}.corner-b{right:33px}.tile-heading{display:flex;justify-content:space-between;gap:10px;padding:0 28px;margin-top:5px;font-size:10px;letter-spacing:1.1px;color:var(--muted)}.tile-heading span:last-child{font-size:11px;letter-spacing:0}.tiles{display:flex;justify-content:center;gap:10px;padding:16px 28px 23px;flex-wrap:wrap;min-height:122px}.number-tile{position:relative;background:#edece4;color:#242b2b;border-radius:8px;border:2px solid transparent;border-bottom:5px solid #bcbfb5;flex:1;max-width:104px;min-width:64px;height:91px;font-size:34px;font-weight:600;line-height:1;font-family:var(--mono);letter-spacing:-2px}.number-tile:hover:not(:disabled){background:#fffef5;transform:translateY(-3px)}.number-tile[aria-pressed=true]{background:var(--orange);border-color:var(--orange);border-bottom-color:#c26a2d;transform:translateY(-4px);box-shadow:0 0 0 3px #ff9d5920}.number-tile.result-tile{background:#c7d9c1;border-bottom-color:#7d9b76}.number-tile .tile-origin{position:absolute;left:8px;top:7px;font:9px var(--font);letter-spacing:0;opacity:.65}.number-tile .tile-order{position:absolute;right:6px;top:5px;font:10px var(--mono)}.number-tile.large-number{font-size:22px;letter-spacing:-1px}.operation-row{display:flex;align-items:center;justify-content:center;gap:22px;margin:0 28px 26px}.operations{display:flex;gap:8px}.operations button{font-size:27px;width:48px;height:45px;background:#2a3031;border:1px solid #454e4f;border-radius:7px;line-height:1}.operations button:hover{background:#3c4545}.operations button[aria-pressed=true]{border-color:var(--orange);color:var(--orange);background:#423328}.operation-hint{font-size:11px;color:var(--muted);line-height:1.5}.expression-bar{display:flex;align-items:center;gap:10px;background:#141819;border:1px solid #353c3d;border-radius:8px;margin:0 28px;padding:10px 11px 10px 18px;min-height:66px}.expression-bar>div{flex:1;font:21px var(--mono);letter-spacing:-.5px}.expression-bar .empty-expression{font:12px var(--font);letter-spacing:0;color:#919d9e}.expression-bar .expression-op{color:var(--orange)}.primary-button{display:inline-flex;align-items:center;justify-content:center;gap:25px;min-height:43px;background:var(--orange);color:#221c16;padding:10px 18px;border-radius:6px;font-weight:650;font-size:14px}.primary-button:hover:not(:disabled){background:#ffb37e}.primary-button:disabled{background:#45413c;color:#b5afa6;opacity:.7}.board-actions{display:flex;align-items:center;justify-content:space-between;gap:10px;margin:17px 28px 23px}.board-actions>div{display:flex;gap:18px}.text-button{background:transparent;color:var(--muted);padding:4px 0;font-size:12px}.text-button:hover:not(:disabled){color:var(--text)}#undo-button,#reset-button{font-size:18px}#undo-button span,#reset-button span{font-size:12px;margin-left:5px}#swap-button{font-size:24px;width:30px;flex-shrink:0}.board-bottom{border-top:1px solid var(--line);padding:12px 26px;display:flex;align-items:center;justify-content:space-between;gap:10px}.board-bottom>span{font-size:9px;letter-spacing:1.2px;color:var(--muted)}.small-dot{display:inline-block;width:5px;height:5px;border-radius:50%;background:#a9cda2;margin-right:7px}.side-panel{display:flex;flex-direction:column;gap:20px}.streak-card{display:flex;gap:16px;padding:22px 21px;border:1px solid #445043;background:linear-gradient(120deg,#293327,#20271f);border-radius:10px}.streak-icon{font-size:43px;line-height:1.5;color:#bed5a8}.streak-card .eyebrow{font-size:9px;color:#b8cca8;letter-spacing:1.3px}.streak-card h2{font-size:25px;letter-spacing:-1px;margin:6px 0}.streak-card p{font-size:12px;color:#b5c0b0}.journey-card,.leaderboard-card{padding:21px 20px;background:#1b1f20;border:1px solid var(--line);border-radius:10px}.section-heading{display:flex;align-items:center;justify-content:space-between;gap:12px}.section-heading h2{font-size:16px;font-weight:500;letter-spacing:-.3px}.section-heading>span{font-size:11px;color:var(--muted)}.empty-history{display:flex;gap:13px;align-items:center;padding:30px 0 12px;color:#939fa0}.empty-history>span{font-size:28px;color:#606e70}.empty-history p{font-size:12px;line-height:1.8}.history{margin:17px 0 0;padding:0;list-style:none;max-height:216px;overflow:auto}.history:empty{display:none}.history li{display:flex;gap:14px;align-items:center;margin-top:9px;padding:7px 0;border-bottom:1px solid #303637;font:15px var(--mono)}.history li .move-index{font-size:10px;color:#879293;border:1px solid #404a4b;border-radius:50%;width:21px;height:21px;display:grid;place-content:center;flex-shrink:0}.history li b{color:var(--orange);font-weight:400}.pill{font:8px var(--mono)!important;border:1px solid #465050;border-radius:4px;padding:3px 5px;letter-spacing:.5px}.mini-leaderboard{margin:19px 0 12px}.mini-leaderboard p{font-size:12px;line-height:1.7}.ranking-row{display:flex;gap:10px;align-items:center;padding:10px 0;border-bottom:1px solid #303637;font-size:12px}.rank{font:11px var(--mono);color:var(--muted);width:16px;flex-shrink:0}.ranking-name{flex:1;min-width:0;overflow-wrap:anywhere}.ranking-score{font:13px var(--mono);color:var(--text)}.ranking-row.is-you .ranking-name{color:var(--orange)}.leaderboard-link{background:transparent;display:flex;align-items:center;justify-content:space-between;width:100%;font-size:12px;color:var(--muted);padding:7px 0 0}.tip{color:#a4adae;font-size:12px;line-height:1.8;padding:0 6px}.tip>span{display:block;font:9px var(--mono);letter-spacing:1.2px;color:var(--orange);margin-bottom:6px}.rules-strip{display:grid;grid-template-columns:repeat(3,1fr);padding:27px 0;gap:28px}.rules-strip>div{display:flex;align-items:flex-start;gap:12px}.rules-strip>div>span{font:11px var(--mono);color:var(--orange);margin-top:3px}.rules-strip p{font-size:12px;color:var(--muted);line-height:1.8}.rules-strip strong{color:#d7dcd7;font-weight:500}footer{border-top:1px solid var(--line);padding:22px 0 25px;display:flex;justify-content:space-between;gap:15px;color:#909a9b;font-size:11px}footer i{font-style:normal;margin:0 10px}.welcome{text-align:center;min-height:470px;padding:50px 20px 33px;display:flex;flex-direction:column;align-items:center;justify-content:center;background:radial-gradient(ellipse at 50% 35%,#3334285c,transparent 70%)}.welcome-art{position:relative;display:flex;gap:10px;align-items:center;margin-bottom:30px}.welcome-art>span{display:grid;place-content:center;width:55px;height:65px;background:#edece4;color:#293030;border-radius:6px;font-size:36px;box-shadow:0 4px 0 #a8aca3;transform:rotate(-7deg)}.welcome-art>span:nth-child(2){background:var(--orange);transform:translateY(-9px) rotate(3deg);box-shadow:0 4px 0 #b76630}.welcome-art>span:nth-child(3){transform:rotate(9deg)}.welcome-art i{position:absolute;right:-33px;top:-24px;font:24px var(--mono);color:var(--orange)}.welcome>.eyebrow{font-size:9px}.welcome h2{font-size:32px;line-height:1.18;margin:15px 0}.welcome p{font-size:14px;line-height:1.75;color:var(--muted);margin-bottom:25px}.welcome-footnote{font-size:11px;color:var(--muted);margin-top:13px}.notice{border:1px solid #8b623e;background:#342a21;color:#ffd2af;padding:12px 17px;margin-bottom:18px;border-radius:7px;font-size:14px}.target-reached{margin:20px 28px 0;border:1px solid #607353;background:#283526;border-radius:8px;padding:15px;display:flex;align-items:center;justify-content:space-between;gap:15px}.target-reached strong{font-size:15px;color:#cee2c2}.target-reached p{font-size:12px;color:#bccbb5;margin-top:3px}.target-reached .primary-button{background:#c4ddb4;font-size:12px}.skip-link{position:fixed;left:20px;top:-70px;background:var(--orange);color:#141819;padding:10px 18px;z-index:99;border-radius:5px}.skip-link:focus{top:10px}dialog{max-width:500px;width:calc(100% - 32px);max-height:90dvh;overflow:auto;color:var(--text);background:#202627;border:1px solid #4b5556;border-radius:16px;padding:36px;box-shadow:0 30px 100px #0008}dialog::backdrop{background:#070c0ec9;backdrop-filter:blur(6px)}dialog h2{font-size:32px;margin:11px 0 20px}dialog p{font-size:14px;color:#b8c2c3;line-height:1.8;margin:14px 0}.dialog-close{position:absolute;right:15px;top:10px;background:transparent;color:var(--muted);font-size:25px;padding:3px 8px}.rule-list{padding-left:19px;font-size:14px;color:#c5cece}.rule-list li{padding-left:5px;margin:10px 0}.example-equation{display:flex;align-items:center;justify-content:center;gap:14px;padding:20px 0}.example-equation span{background:#e6e7dd;color:#222829;border-radius:6px;padding:7px 13px;font:26px var(--mono)}.example-equation b{font-size:20px;color:var(--orange)}.shortcut-note{padding:15px;border-radius:7px;background:#171d1e;font-size:12px!important}.wide{width:100%;margin-top:14px}.muted{color:var(--muted)}.small{font-size:12px!important}.secondary-button{background:transparent;border:1px solid #586362;border-radius:6px;min-height:43px;color:#d1d8d5;font-size:14px;padding:10px}.name-label{display:block;font-size:14px;margin-bottom:7px}input,textarea{color:var(--text);width:100%;background:#141a1b;border:1px solid #596566;padding:12px;border-radius:6px}textarea{resize:vertical;margin-top:15px;font-size:13px}.result-spark{font-size:55px;line-height:1;color:var(--orange);margin-bottom:24px}#result-dialog{text-align:center}.result-score{display:flex;flex-direction:column;align-items:center;padding:18px 0}.result-score strong{font:56px var(--mono);letter-spacing:-3px;color:var(--orange)}.result-score>span{font-size:10px;letter-spacing:2px;color:var(--muted)}.result-metrics{display:grid;grid-template-columns:repeat(3,1fr);padding:17px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.result-metrics span{display:block;font-size:10px;color:var(--muted);letter-spacing:1px}.result-metrics strong{font:18px var(--mono)}.stats-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:24px 0}.stats-grid>div{padding:18px;background:#151c1d;border-radius:8px}.stats-grid strong{display:block;font:30px var(--mono);color:var(--orange)}.stats-grid span{font-size:12px;color:var(--muted)}#full-leaderboard .ranking-row{font-size:14px;padding:14px 0}#full-leaderboard .ranking-score{font-size:14px}.board-complete .number-tile:disabled{opacity:1}.board-complete .operations{opacity:.5}#turnstile-container{margin-bottom:12px;max-width:100%;overflow:hidden}body.loading{cursor:progress}
@media(min-width:1500px){.shell{max-width:1320px;padding:0 55px}.game-layout{grid-template-columns:minmax(0,1fr) 320px}.target-area{padding:35px 15px}.target-ring strong{font-size:112px}.tiles{padding-bottom:26px}.number-tile{height:99px}.welcome{min-height:511px}}
@media(max-width:1050px){.shell{padding:0 28px}.game-layout{grid-template-columns:minmax(0,1fr) 260px;gap:18px}.side-panel{gap:16px}.streak-card{padding:18px 14px;gap:10px}.streak-card h2{font-size:23px}.journey-card,.leaderboard-card{padding:19px 15px}.brand small{display:none}.number-tile{min-width:48px;font-size:29px;height:82px}.tiles{gap:7px;padding:16px 20px 20px}.expression-bar{margin:0 20px}.tile-heading{padding:0 20px}.operation-row{gap:13px;margin:0 20px 24px}.operations button{width:43px}.operation-hint{font-size:10px}.target-reached{margin:20px 20px 0;flex-wrap:wrap}.board-label{font-size:9px}.board-top{padding:18px 20px}}
@media(max-width:800px){.shell{max-width:640px;padding:0 22px}.site-header{min-height:86px}.site-header nav{gap:18px}.brand{font-size:26px}.game-layout{grid-template-columns:1fr}.page-heading{align-items:start;gap:15px;flex-wrap:wrap;margin:27px 0 22px}h1{font-size:34px}.page-heading p{font-size:14px}.difficulty-label{flex-direction:row;align-items:center;gap:12px}.date-label{font-size:11px}.side-panel{display:grid;grid-template-columns:1fr 1fr;gap:15px}.streak-card{grid-column:1 / -1;align-items:center;padding:16px 20px}.streak-card>div:last-child{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:3px 20px;width:100%}.streak-card .eyebrow{grid-column:1}.streak-card h2{grid-column:1;margin:0}.streak-card p{grid-column:2;grid-row:1/3;justify-self:end}.streak-icon{font-size:36px;line-height:1}.tip{display:none}.rules-strip{gap:18px;padding:25px 0}.rules-strip p{font-size:11px}.rules-strip>div{gap:8px}.rules-strip>div>span{font-size:10px}.number-tile{height:90px;font-size:34px;max-width:100px}.tile-heading{padding:0 26px}.tiles{padding:16px 26px 23px;gap:9px}.expression-bar{margin:0 26px}.board-actions{margin:17px 26px 22px}.board-top{padding:18px 26px}.board-label{font-size:10px}.operation-row{gap:23px}.operation-hint{font-size:11px}.operations button{width:48px}.welcome{min-height:456px}footer{font-size:10px;flex-wrap:wrap}.target-reached{margin:20px 26px 0}}
@media(max-width:460px){.shell{padding:0 15px}.site-header{min-height:78px}.brand{font-size:24px}.nav-button{font-size:12px}.site-header nav{gap:14px}.help-button{width:27px;height:27px;font-size:14px}.brand-mark{margin-right:10px}.topline{margin-top:22px;gap:10px}.mode-switch button{padding:7px 13px;font-size:12px}.date-label{max-width:115px;text-align:right;line-height:1.6;font-size:10px}.page-heading{margin-top:24px}h1{font-size:29px}.page-heading p{font-size:13px}.eyebrow{font-size:9px}.difficulty-label{font-size:11px}select{padding:8px 22px 8px 10px;font-size:12px}.board-top{padding:15px 17px}.board-label{font-size:9px}.board-label>span{margin-right:5px}.metrics{gap:16px}.metrics strong{font-size:16px}.metrics span{font-size:8px}.target-area{padding:25px 10px 22px}.target-ring strong{font-size:87px}.tile-heading{padding:0 17px}.tile-heading span{font-size:9px}.tile-heading span:last-child{font-size:10px}.tiles{gap:6px;padding:13px 17px 21px;min-height:108px}.number-tile{min-width:40px;height:75px;font-size:28px;border-radius:6px;letter-spacing:-1px}.number-tile .tile-origin{font-size:8px;left:4px}.number-tile.large-number{font-size:17px;letter-spacing:-1px}.operation-row{gap:14px;margin:0 17px 22px}.operations{gap:7px}.operations button{width:40px;height:42px;font-size:25px}.operation-hint{font-size:10px}.expression-bar{margin:0 17px;gap:5px;padding:8px 8px 8px 12px}.expression-bar>div{font-size:18px}.expression-bar .empty-expression{font-size:10px}.expression-bar .primary-button{padding:9px 12px;gap:12px;font-size:12px}.board-actions{margin:14px 17px 18px}.board-bottom{padding:11px 17px}.board-bottom>span{font-size:8px;letter-spacing:.7px}.board-bottom .text-button{font-size:10px}.target-caption{font-size:11px}.welcome{padding:40px 18px 30px;min-height:440px}.welcome h2{font-size:29px}.welcome>.eyebrow{font-size:8px;letter-spacing:1px}.welcome p{font-size:13px}.side-panel{grid-template-columns:1fr}.streak-card{padding:16px}.journey-card,.leaderboard-card{padding:18px}.empty-history{padding:18px 0 0}.empty-history p br{display:none}.history{max-height:180px}.streak-card p{font-size:11px;max-width:120px}.rules-strip{grid-template-columns:1fr;gap:12px;padding:24px 4px}.rules-strip p{font-size:12px}.rules-strip br{display:none}.rules-strip strong{margin-right:5px}.rules-strip>div{gap:12px}.target-reached{margin:18px 17px 0}.target-reached .primary-button{width:100%}dialog{padding:30px 23px}dialog h2{font-size:28px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

.security-screen{position:fixed;inset:0;z-index:1000;display:grid;place-items:center;padding:24px;background:radial-gradient(circle at 50% 42%,#2a302b 0,#171b1c 48%,#101314 100%)}
.security-card{width:min(430px,100%);display:flex;flex-direction:column;align-items:center;text-align:center;padding:38px 30px 34px;border:1px solid var(--line);border-radius:16px;background:#1b1f20;box-shadow:0 28px 90px #0008}
.security-brand{display:flex;align-items:center;margin-bottom:34px;color:var(--text)}
.security-brand strong{font-size:23px;letter-spacing:-.8px}
.security-brand strong span{color:var(--orange);font-weight:400}
.security-loader{display:flex;align-items:center;gap:7px;margin-bottom:27px}
.security-loader span{display:grid;place-items:center;width:42px;height:50px;border-radius:5px;background:#edece4;color:#293030;font:27px var(--mono);box-shadow:0 3px 0 #9da19a;transform:rotate(-6deg)}
.security-loader span:nth-child(2){background:var(--orange);box-shadow:0 3px 0 #b76630;transform:translateY(-6px) rotate(3deg)}
.security-loader span:nth-child(3){transform:rotate(7deg)}
.security-card h1{font-size:31px;margin:12px 0 9px}
.security-card p{max-width:310px;margin-bottom:24px;color:var(--muted);font-size:14px}
.security-card #turnstile-container{width:100%;display:flex;justify-content:center;margin:0}
body.security-pending{overflow:hidden}
body.security-pending>.shell,body.security-pending>.skip-link{visibility:hidden}
@media(max-width:460px){.security-card{padding:32px 18px 28px}.security-card h1{font-size:28px}}