:root{color-scheme:light;--bg:#f6f5ef;--paper:#fffefa;--ink:#243f39;--green:#286b58;--line:#dce4dc;--muted:#62756d}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:system-ui,-apple-system,"Segoe UI","Microsoft YaHei",sans-serif;line-height:1.65}button,input,select{font:inherit}a{color:inherit;text-decoration:none}button,a,input,select{outline-offset:5px}button{cursor:pointer}button:disabled,[aria-disabled=true]{cursor:default}header,main,footer{width:min(1120px,calc(100% - 48px));margin:auto}.site-header{display:flex;align-items:center;justify-content:space-between;padding:30px 0}.brand{display:inline-flex;align-items:center;gap:9px;font-size:15px}.brand svg{width:25px;height:25px;fill:var(--bg);stroke:var(--green);stroke-width:1.5}.text-button{border:0;background:none;color:var(--green);min-height:44px;padding:8px}.hero{display:grid;grid-template-columns:1.1fr 1fr;gap:72px;align-items:center;min-height:620px;padding:32px 0 68px}.eyebrow{color:var(--green);font-size:14px;letter-spacing:.08em}h1{font-family:Georgia,"Songti SC",SimSun,serif;font-size:clamp(40px,5vw,64px);font-weight:400;line-height:1.2;margin:20px 0}.lead{font-size:22px;max-width:24em}.intro{color:var(--muted);max-width:30em}.stores{display:flex;gap:12px;margin-top:30px;flex-wrap:wrap}.store{background:var(--ink);color:white;padding:13px 20px;border-radius:13px;min-width:176px;display:flex;flex-direction:column}.store span{font-weight:600;font-size:16px}.store small{opacity:.8;font-size:13px}.store-note,.language-note{font-size:13px;color:var(--muted)}.puzzle-preview{background:var(--paper);padding:32px;border:1px solid var(--line);border-radius:30px;box-shadow:0 18px 55px #24423709}.preview-label{color:var(--green);font-size:13px}.preview-question{font-size:17px}.number-demo{display:grid;grid-template-columns:1fr 36px 1fr;text-align:center;align-items:center;gap:12px;font-size:42px;padding:20px 0;font-family:Georgia,serif}.number-demo i{font-style:normal;font-size:24px;color:var(--muted)}#demo{display:flex;gap:10px}#demo input{width:0;flex:1;min-width:0;border:1px solid var(--line);border-radius:12px;text-align:center;background:transparent;font-size:24px;color:var(--ink)}#demo button,.primary{background:var(--green);color:white;padding:12px 20px;border:0;border-radius:12px;min-height:48px}#demo-feedback{min-height:52px;font-size:17px;margin:12px 0;color:var(--green)}.preview-foot{font-size:12px;color:var(--muted)}.features{display:grid;grid-template-columns:repeat(3,1fr);gap:36px;border-top:1px solid var(--line);padding:40px 0}.features article>span{font-size:13px;color:var(--green)}.features h2{font-size:22px;font-weight:500}.features p{color:var(--muted);font-size:16px}footer{border-top:1px solid var(--line);display:flex;justify-content:space-between;gap:20px;padding:28px 0;margin-top:42px;font-size:13px;color:var(--muted)}footer nav{display:flex;gap:20px}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%)}.document{max-width:760px;padding:40px 0}.document h1{font-size:36px}.document h2{font-size:22px;margin-top:32px}.admin-head{display:flex;justify-content:space-between;align-items:center;gap:16px}.admin-head h1{font-size:32px}.admin-login{max-width:480px;margin:60px auto;padding:28px;border:1px solid var(--line);border-radius:20px;background:var(--paper)}.admin-login label{display:block}.admin-login input{width:100%;padding:12px;border:1px solid var(--line);border-radius:10px;margin:10px 0 18px}.admin-tools{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.admin-tools select,.admin-tools input{padding:10px;border:1px solid var(--line);border-radius:8px;max-width:100%;background:var(--paper);color:var(--ink)}.stats-summary{display:flex;gap:28px;padding:24px 0;flex-wrap:wrap}.stats-summary strong{font-size:28px;display:block}.stats-summary span{font-size:13px;color:var(--muted)}.stats-table{width:100%;border-collapse:collapse;font-size:14px}.stats-table th,.stats-table td{border-bottom:1px solid var(--line);padding:14px 10px;text-align:left}.stats-table th{font-weight:500;color:var(--muted)}.stats-table td small{display:block;color:var(--muted)}.stats-table td:first-child{min-width:150px}.table-wrap{overflow-x:auto}#status{min-height:28px;color:#a33d2b}[hidden]{display:none!important}@media(max-width:900px){.hero{gap:28px;min-height:540px}.stores{gap:10px}.store{min-width:150px;padding:12px 15px}.puzzle-preview{padding:24px}.features{gap:24px}.lead{font-size:20px}}@media(max-width:600px){header,main,footer{width:calc(100% - 36px)}.site-header{padding:18px 0}.hero{grid-template-columns:1fr;gap:26px;padding:12px 0 36px;min-height:0}h1{font-size:44px;margin:16px 0}.lead{font-size:21px}.intro{font-size:15px}.stores{flex-wrap:nowrap;margin-top:24px}.store{min-width:0;flex:1;padding:12px}.store span{font-size:14px}.store-note{font-size:12px}.puzzle-preview{padding:24px}.number-demo{font-size:36px}.features{grid-template-columns:1fr;gap:16px;padding:28px 0}.features h2{margin:6px 0}.features p{margin:8px 0}footer{flex-direction:column;gap:10px}.admin-head h1{font-size:26px}.admin-tools label{width:100%}.admin-tools input{width:100%}.stats-table th,.stats-table td{padding:12px 7px;font-size:13px}.stats-summary{gap:20px}}
@media(max-width:600px){.stats-table thead{display:none}.stats-table,.stats-table tbody{display:block}.stats-table tr{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));background:var(--paper);border:1px solid var(--line);border-radius:14px;padding:10px;margin:12px 0}.stats-table td{display:block;border:0;padding:6px;font-size:15px}.stats-table td:first-child{grid-column:1/-1;font-size:14px;border-bottom:1px solid var(--line);margin-bottom:6px;min-width:0}.stats-table td:not(:first-child):before{content:attr(data-label);display:block;white-space:nowrap;font-size:12px;color:var(--muted);margin-bottom:6px}}

.policy{max-width:740px;padding:24px;margin:auto;overflow-wrap:anywhere}.policy h1{font-size:clamp(24px,5vw,38px)}.policy h2{margin:32px 0 12px;font-size:21px}.policy p{font-size:16px;line-height:1.85}.brand img{border-radius:7px}footer nav{flex-wrap:wrap}

.policy-main{width:100%}.policy-main .policy{width:min(740px,calc(100% - 36px));padding:24px 0}.policy-language{display:flex;align-items:center;gap:8px;font-size:13px}.policy-language select{min-height:44px;max-width:145px;background:var(--paper);color:var(--ink);border:1px solid var(--line);border-radius:8px;padding:6px}.policy-language span{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%)}

/* 2026-10-26 Logic Puzzles vivid-v2 brand; layout preserved. */
:root{--brand-surface:#FFFFFF;--brand-surfaceRaised:#FFFFFF;--brand-textPrimary:#183A36;--brand-textSecondary:#4A5D58;--brand-textMuted:#5B6B65;--brand-border:#E8DDCB;--brand-controlBorder:#7B897D;--brand-onPrimary:#173D3B;--brand-onAccent:#173D3B;--brand-disabledSurface:#FFFEFC;--brand-disabledText:#84908C;--brand-success:#24724F;--brand-successSurface:#E8F4EB;--brand-successBorder:#3D865F;--brand-danger:#A23E35;--brand-dangerSurface:#FBECE8;--brand-dangerBorder:#AD4B40;--brand-warning:#7C5315;--brand-warningSurface:#FFF2D6;--brand-warningBorder:#987330;--brand-info:#275D83;--brand-infoSurface:#E9F2FA;--brand-infoBorder:#497CA0;--brand-mint:#85D0C8;--brand-onMint:#173D3B;--brand-background:#FFFAF3;--brand-surfaceSubtle:#E4F7EE;--brand-primary:#FF9A3D;--brand-primarySoft:#FFE8BB;--brand-accent:#85D0C8;--brand-primaryHover:#FF922F;--brand-primaryPressed:#F9841F;--brand-onPrimarySoft:#A93708;--brand-onDanger:#FFFFFF;--brand-toastBackground:#183A36;--brand-toastText:#FAF5ED;--brand-selectedSurface:#FFE8BB;--brand-selectedBorder:#B53E0B;--brand-focus:#B53E0B;--brand-link:#B53E0B;--brand-hoverSurface:#FFF7EF;--brand-pressedSurface:#FFF1E4;--brand-inputSurface:#FFFFFF;--brand-inputText:#183A36;--brand-placeholder:#5B6B65;--brand-targetSurface:#FFE8BB;--brand-targetText:#A93708;--brand-tileSurface:#FFFFFF;--brand-tileText:#183A36;--brand-tileBorder:#7B897D;--brand-tileSelected:#FFE8BB;--brand-tileSelectedText:#A93708;--brand-tileUsedSurface:#FFFEFC;--brand-tileUsedText:#84908C;--brand-hintSurface:#E9F2FA;--brand-hintText:#275D83;--brand-diagramGiven:#183A36;--brand-diagramConstruction:#B53E0B;--brand-diagramAnswer:#24724F;--brand-diagramGrid:#D4DDD7;--brand-loadingTrack:#D4DDD7;--brand-loadingIndicator:#B53E0B;--brand-shadow:rgba(23,61,59,0.10);--brand-scrim:rgba(7,24,20,0.48);--bg:var(--brand-background);--paper:var(--brand-surface);--ink:var(--brand-textPrimary);--green:var(--brand-link);--line:var(--brand-border);--muted:var(--brand-textSecondary);color-scheme:light}@media(prefers-color-scheme:dark){:root{--brand-textPrimary:#E9F1EB;--brand-textSecondary:#B8C9C1;--brand-textMuted:#AEC2B7;--brand-border:#46564E;--brand-controlBorder:#9BB0A6;--brand-onPrimary:#173D3B;--brand-onAccent:#173D3B;--brand-disabledSurface:#283028;--brand-disabledText:#8D9E94;--brand-success:#91D5AE;--brand-successSurface:#173D2B;--brand-successBorder:#61A77D;--brand-danger:#FFB4A7;--brand-dangerSurface:#4B2524;--brand-dangerBorder:#CD8377;--brand-warning:#EBC78B;--brand-warningSurface:#423521;--brand-warningBorder:#B9985A;--brand-info:#A6D0EE;--brand-infoSurface:#203A4B;--brand-infoBorder:#6C9DBB;--brand-mint:#85D0C8;--brand-onMint:#173D3B;--brand-background:#20251F;--brand-surface:#2A332B;--brand-surfaceRaised:#344036;--brand-surfaceSubtle:#243F34;--brand-primary:#FFAC5A;--brand-primarySoft:#483324;--brand-accent:#85D0C8;--brand-primaryHover:#FFB86C;--brand-primaryPressed:#FFA14A;--brand-onPrimarySoft:#FFE3C5;--brand-onDanger:#172A23;--brand-toastBackground:#E9F1EB;--brand-toastText:#261E18;--brand-selectedSurface:#483324;--brand-selectedBorder:#FFBC78;--brand-focus:#FFBC78;--brand-link:#FFBC78;--brand-hoverSurface:#3B3D2F;--brand-pressedSurface:#484432;--brand-inputSurface:#2A332B;--brand-inputText:#E9F1EB;--brand-placeholder:#AEC2B7;--brand-targetSurface:#483324;--brand-targetText:#FFE3C5;--brand-tileSurface:#344036;--brand-tileText:#E9F1EB;--brand-tileBorder:#9BB0A6;--brand-tileSelected:#483324;--brand-tileSelectedText:#FFE3C5;--brand-tileUsedSurface:#283028;--brand-tileUsedText:#8D9E94;--brand-hintSurface:#203A4B;--brand-hintText:#A6D0EE;--brand-diagramGiven:#E9F1EB;--brand-diagramConstruction:#FFBC78;--brand-diagramAnswer:#91D5AE;--brand-diagramGrid:#46564E;--brand-loadingTrack:#46564E;--brand-loadingIndicator:#FFBC78;--brand-shadow:rgba(0,0,0,0.24);--brand-scrim:rgba(0,0,0,0.64);--bg:var(--brand-background);--paper:var(--brand-surface);--ink:var(--brand-textPrimary);--green:var(--brand-link);--line:var(--brand-border);--muted:var(--brand-textSecondary);color-scheme:dark}}
#demo button,.primary{background:var(--brand-primary);color:var(--brand-onPrimary)}#demo button:hover,.primary:hover{background:var(--brand-primaryHover)}#demo button:active,.primary:active{background:var(--brand-primaryPressed)}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid var(--brand-focus);outline-offset:3px}.brand img{border-radius:22%}.store[aria-disabled=true]{background:var(--brand-disabledSurface);color:var(--brand-disabledText);border:1px solid var(--brand-border)}#demo input{background:var(--brand-inputSurface);border-color:var(--brand-controlBorder)}