:root{--paper:#f8f7f2;--panel:#fff;--ink:#0b1f40;--blue:#0868bd;--blue-dark:#064f91;--blue-soft:#e5f2ff;--gold:#d99a16;--gold-soft:#fff2cf;--green:#198754;--green-soft:#e4f5eb;--line:#cbd3df;--muted:#667186;--shadow:0 12px 32px #0b1f4012}*{box-sizing:border-box}html{background:var(--paper)}body{background:var(--paper);color:var(--ink);margin:0;font-family:Arial,Helvetica,sans-serif}button,select{font:inherit}button{border:1px solid var(--line);background:var(--panel);min-height:34px;color:var(--ink);cursor:pointer;border-radius:8px;padding:6px 12px}button:hover:not(:disabled){border-color:var(--blue);color:var(--blue)}button:focus-visible,select:focus-visible,[tabindex]:focus-visible{outline-offset:2px;outline:3px solid #0868bd40}button:disabled{cursor:default;opacity:.42}a{color:var(--blue-dark);text-underline-offset:3px}.site-shell{width:min(1540px,100%);min-height:100svh;margin:0 auto;padding:14px 18px 8px}.eyebrow{color:#9b6500;letter-spacing:.19em;text-transform:uppercase;margin:0 0 5px;font-size:11px;font-weight:800}.masthead{border-bottom:1px solid var(--line);grid-template-columns:minmax(260px,1fr) auto 265px auto;align-items:end;gap:18px;padding:2px 4px 12px;display:grid}.brand h1{letter-spacing:-.04em;margin:0;font-size:clamp(30px,3.2vw,42px);line-height:.95}.brand h1 span{color:var(--blue)}.brand h1 b{color:var(--gold);font-weight:800}.tagline{color:var(--muted);margin:6px 0 0;font-size:14px}.top-nav{align-items:center;gap:4px;display:flex}.top-nav button{background:0 0;border-color:#0000;font-size:13px}.top-nav button.active{border-color:var(--ink);background:var(--ink);color:#fff;font-weight:700}.puzzle-picker{gap:4px;display:grid}.puzzle-picker span{color:var(--muted);letter-spacing:.1em;text-transform:uppercase;font-size:10px;font-weight:700}.puzzle-picker select{border:1px solid var(--line);min-height:38px;color:var(--ink);background:#fff;border-radius:9px;padding:6px 34px 6px 10px;font-weight:700}.progress{text-transform:uppercase;grid-template-columns:auto;place-items:baseline end;display:grid}.progress strong{font-size:32px;line-height:1}.progress small{font-size:14px}.progress span{color:var(--muted);letter-spacing:.08em;white-space:nowrap;margin-top:3px;font-size:9px}.game-card,.content-card{border:1px solid var(--line);background:var(--panel);box-shadow:var(--shadow);border-radius:22px;margin-top:12px;overflow:hidden}.game-card{flex-direction:column;height:calc(100svh - 150px);min-height:500px;display:flex}.puzzle-strip{border-bottom:1px solid var(--line);justify-content:space-between;align-items:center;min-height:48px;padding:8px 16px;display:flex}.puzzle-strip div{flex-wrap:wrap;align-items:center;gap:9px;display:flex}.puzzle-strip span{color:var(--muted);letter-spacing:.1em;text-transform:uppercase;font-size:10px}.puzzle-strip strong{font-size:15px}.puzzle-strip i{color:var(--muted);margin-left:auto;font-size:10px;font-style:normal}.strip-actions{align-items:center;gap:6px;display:flex}.check-setting{color:var(--muted);font-size:10px}.puzzle-strip em,.archive-grid em{border-radius:999px;padding:3px 8px;font-size:10px;font-style:normal;font-weight:700}.puzzle-strip em.easy,.archive-grid em.easy{color:#0664b6;background:#e5f2ff}.puzzle-strip em.standard,.archive-grid em.standard{color:#986300;background:#fff1cc}.puzzle-strip em.challenging,.archive-grid em.challenging{color:#6d37a8;background:#f1e7ff}.game-layout{flex:1;grid-template-columns:185px minmax(500px,1fr) 292px;align-items:center;gap:14px;min-height:0;padding:10px 16px 4px;display:grid}.number-panel{flex-direction:column;justify-content:center;align-self:stretch;padding:8px 0;display:flex}.mode-switch{background:#edf0f5;border-radius:9px;width:max-content;margin-bottom:12px;padding:2px;display:flex}.mode-switch button{background:0 0;border:0;min-height:30px;padding:4px 12px}.mode-switch button.active{background:var(--ink);color:#fff;font-weight:700;box-shadow:0 1px 3px #0b1f402e}.panel-heading span{color:#9b6500;letter-spacing:.16em;font-size:10px;font-weight:800;display:block}.panel-heading strong{margin-top:3px;font-size:17px;display:block}.number-bank{grid-template-columns:repeat(6,1fr);gap:4px;margin-top:10px;display:grid}.number-bank button{min-height:32px;padding:2px;font-size:12px}.number-bank button.used{color:#a1a7b1;background:#f2f3f5;text-decoration:line-through}.number-bank button.candidate{border-color:var(--gold);background:var(--gold-soft);color:#7d5100;font-weight:800}.erase-button{width:100%;margin-top:6px}.mode-note{color:var(--muted);margin:9px 0 0;font-size:10px;line-height:1.35}.board-panel{align-self:center;min-width:0}.board{width:100%;min-height:330px;max-height:calc(100svh - 268px);display:block}.triangle-cell{cursor:pointer}.triangle-cell polygon{fill:#fff;stroke:var(--ink);stroke-width:2.1px;stroke-linejoin:round;transition:fill .12s,stroke .12s}.triangle-cell.active polygon{fill:var(--gold-soft)}.triangle-cell.selected polygon{fill:var(--blue-soft);stroke:var(--blue);stroke-width:4px}.triangle-cell.given polygon{fill:#fafbfc}.triangle-cell text.entry{fill:var(--blue);text-anchor:middle;dominant-baseline:central;pointer-events:none;font-size:24px;font-weight:800}.triangle-cell.given text.entry{fill:var(--ink)}.pencil-object{pointer-events:none;overflow:visible}.pencil-grid{color:#9b6500;text-align:center;flex-wrap:wrap;place-content:center;align-items:center;gap:2px 4px;width:58px;height:36px;font-size:8.5px;font-weight:800;line-height:1;display:flex}.pencil-grid span{min-width:12px}.target{cursor:pointer}.target circle{fill:var(--gold);stroke:var(--ink);stroke-width:2px}.target text{fill:#111;text-anchor:middle;dominant-baseline:central;pointer-events:none;font-size:14px;font-weight:800}.target.boundary circle{fill:#f2bd4d;stroke-width:1.7px}.target.boundary text{font-size:12px}.target.selected circle{stroke:var(--blue);stroke-width:5px}.target.correct circle{fill:#45b980}.instructions{border-left:1px solid var(--line);flex-direction:column;justify-content:center;align-self:stretch;padding:14px 18px;display:flex}.instructions h2{margin:0 0 10px;font-size:23px}.instructions p{margin:0 0 10px;font-size:13px;line-height:1.5}.target-readout{background:var(--gold-soft);border-radius:10px;margin:10px 0 14px;padding:11px}.target-readout span{color:var(--muted);letter-spacing:.09em;text-transform:uppercase;font-size:10px;display:block}.target-readout strong{margin-top:4px;font-size:21px;display:block}.target-readout small{color:var(--muted);margin-top:3px;font-size:10px;display:block}.greybrow-link{border:1px solid var(--line);color:var(--ink);background:#fafbfc;border-radius:9px;flex-direction:column;gap:2px;margin:-4px 0 12px;padding:9px 10px;text-decoration:none;display:flex}.greybrow-link:hover{border-color:var(--blue);color:var(--blue)}.greybrow-link strong{font-size:12px}.greybrow-link span{color:var(--muted);font-size:10px}.instructions .proof-note{color:var(--green);margin-bottom:0;font-weight:800}.status{text-align:center;background:#f0f2f5;border-radius:10px;margin:0 16px;padding:9px 12px;font-size:13px}.status.success{background:var(--green-soft);color:#08733e;font-weight:800}.actions{justify-content:center;align-items:center;gap:8px;min-height:52px;padding:8px 16px 12px;display:flex}.actions .primary{border-color:var(--blue);background:var(--blue);color:#fff;font-weight:800}.actions .primary:hover:not(:disabled){background:var(--blue-dark);color:#fff}.share-button{align-items:center;gap:6px;display:flex}.share-hex{width:25px;height:25px;overflow:visible}.share-hex polygon{stroke:#101827;stroke-width:1.5px}.share-hex .green{fill:#45b980}.share-hex .grey{fill:#d6d9de}.check-choice{text-align:center;flex-direction:column;flex:1;justify-content:center;align-items:center;padding:30px;display:flex}.check-choice h2{letter-spacing:-.035em;margin:0;font-size:clamp(28px,4vw,46px)}.check-choice>p:not(.eyebrow){color:var(--muted);margin:10px 0 26px}.check-choice>div{grid-template-columns:1fr 1fr;gap:14px;width:min(700px,100%);display:grid}.check-choice button{text-align:left;flex-direction:column;justify-content:center;align-items:flex-start;gap:8px;min-height:150px;padding:24px;display:flex;position:relative}.check-choice button strong{font-size:21px}.check-choice button span{color:var(--muted);line-height:1.45}.check-choice button em{background:var(--blue-soft);color:var(--blue);letter-spacing:.05em;text-transform:uppercase;border-radius:999px;padding:3px 7px;font-size:9px;font-style:normal;font-weight:800;position:absolute;top:12px;right:12px}.check-choice button.recommended{border-color:var(--blue);background:#f7fbff}.content-card{min-height:calc(100svh - 124px);padding:clamp(24px,5vw,64px)}.section-heading{max-width:650px}.section-heading h2{letter-spacing:-.035em;margin:0;font-size:clamp(28px,4vw,48px)}.section-heading>p:last-child{color:var(--muted);margin:10px 0 0;line-height:1.5}.archive-grid{grid-template-columns:repeat(3,1fr);gap:12px;margin-top:32px;display:grid}.archive-grid button{text-align:left;grid-template-columns:1fr auto;align-content:center;gap:7px 12px;min-height:140px;padding:20px;display:grid}.archive-grid button>span{color:var(--muted);letter-spacing:.08em;font-size:11px}.archive-grid button>strong{letter-spacing:-.02em;grid-column:1/-1;font-size:24px}.archive-grid button>em{justify-self:start}.archive-grid button>small{color:var(--muted);align-self:center}.archive-grid button.complete{background:var(--green-soft);border-color:#75b996}.stat-grid{grid-template-columns:repeat(4,1fr);gap:12px;margin-top:32px;display:grid}.stat-grid div{border:1px solid var(--line);border-radius:14px;flex-direction:column;justify-content:center;min-height:125px;padding:20px;display:flex}.stat-grid strong{font-size:40px}.stat-grid span{color:var(--muted);text-transform:uppercase;letter-spacing:.08em;font-size:12px}.result-list{border-top:1px solid var(--line);margin-top:24px}.result-list>div{border-bottom:1px solid var(--line);grid-template-columns:34px 65px 1fr auto;align-items:center;gap:10px;padding:10px 0;display:grid}.result-list span,.result-list em{color:var(--muted);font-size:12px}.result-list em{font-style:normal}.help-columns{grid-template-columns:repeat(4,1fr);gap:14px;margin-top:32px;display:grid}.help-columns article{border:1px solid var(--line);border-radius:14px;padding:20px}.help-columns article>span{background:var(--gold);color:#111;border-radius:50%;place-items:center;width:28px;height:28px;font-weight:800;display:grid}.help-columns h3{margin:18px 0 8px}.help-columns p,.strategy-note p{color:var(--muted);margin:0;line-height:1.55}.strategy-note{background:var(--blue-soft);border-radius:14px;margin-top:16px;padding:20px}.strategy-note h3{margin:0 0 8px}.strategy-note p+p{margin-top:10px}footer{color:var(--muted);justify-content:space-between;gap:24px;padding:10px 5px 2px;font-size:11px;display:flex}footer nav{flex-wrap:wrap;gap:14px;display:flex}footer a{color:var(--muted)}@media (width>=901px){.site-shell{flex-direction:column;height:100svh;min-height:0;display:flex;overflow:hidden}.masthead,footer{flex:none}.game-card{flex:auto;height:auto;min-height:0}.content-card{flex:auto;min-height:0;overflow:auto}}@media (width<=1180px){.masthead{grid-template-columns:minmax(220px,1fr) auto 235px auto;gap:10px}.tagline{font-size:12px}.top-nav button{padding:5px 7px}.game-layout{grid-template-columns:152px minmax(445px,1fr) 245px;gap:8px;padding-inline:10px}.number-bank{grid-template-columns:repeat(4,1fr)}.number-bank button{min-height:29px}.instructions{padding:8px 12px}.instructions p{margin-bottom:7px;font-size:11px}.greybrow-link{margin-bottom:8px;padding:7px 9px}.board{max-height:calc(100svh - 255px)}}@media (width<=900px){.site-shell{padding:8px}.masthead{grid-template-columns:1fr auto;align-items:center}.brand .tagline{display:none}.top-nav{order:3;grid-area:2/1/auto/-1;justify-content:center}.puzzle-picker{grid-area:1/2}.progress{display:none}.game-card,.content-card{border-radius:16px;height:auto;min-height:calc(100svh - 118px);margin-top:8px}.game-layout{grid-template-columns:140px minmax(420px,1fr)}.instructions{border-top:1px solid var(--line);border-left:0;grid-column:1/-1;grid-template-columns:1fr 1fr;gap:5px 18px;padding:12px;display:grid}.instructions .eyebrow,.instructions h2{grid-column:1/-1}.target-readout{grid-area:3/2/6;margin:0}.greybrow-link{grid-column:1;align-self:start;margin:0}.instructions .proof-note{grid-column:1/-1}.board{min-height:340px;max-height:55svh}.archive-grid,.help-columns,.stat-grid{grid-template-columns:repeat(2,1fr)}}@media (width<=650px){.site-shell{padding:5px}.masthead{padding:5px 4px 8px}.brand .eyebrow{display:none}.brand h1{font-size:26px}.puzzle-picker{max-width:210px}.puzzle-picker span{display:none}.puzzle-picker select{width:100%;font-size:11px}.top-nav{justify-content:flex-start;overflow-x:auto}.top-nav button{flex:1;font-size:11px}.game-card{min-height:auto}.puzzle-strip{min-height:42px;padding:6px 8px}.puzzle-strip>div:first-child span,.puzzle-strip i{display:none}.check-setting{white-space:normal;max-width:112px;padding-inline:6px;line-height:1.1}.game-layout{flex-direction:column;padding:5px;display:flex}.board-panel{order:1;width:100%}.board{min-height:0;max-height:none}.number-panel{order:2;width:100%;padding:2px 5px 8px}.mode-switch{margin:0 0 7px}.panel-heading{justify-content:space-between;align-items:baseline;display:flex}.number-bank{grid-template-columns:repeat(7,1fr);margin-top:6px}.number-bank button{min-height:35px}.mode-note{text-align:center}.instructions{order:3;width:100%;padding:14px 10px;display:block}.target-readout{margin:10px 0}.greybrow-link{margin:0 0 10px}.status{margin:0 6px}.actions{padding:8px}.check-choice{padding:35px 16px}.check-choice>div{grid-template-columns:1fr}.check-choice button{min-height:125px}.content-card{min-height:auto;padding:24px 16px}.archive-grid,.help-columns,.stat-grid{grid-template-columns:1fr}.archive-grid button{min-height:112px}.result-list>div{grid-template-columns:30px 55px 1fr}.result-list em{grid-column:3}.section-heading h2{font-size:30px}footer{padding:12px 6px;display:block}footer nav{margin-top:8px}}
