:root{--bg:#0d1219;--page:#eff4ed;--card:#f1f2ea;--ink:#16211e;--muted:#53645b;--soft:#e0e5db;--line:#d1d9ce;--input:#fbfcf8;--lime:#d8ff73;--sidebar:#1c2832;--side-border:#344750;--side-muted:#a6b7bd;--side-value:#d8ff73;--button:#1b2e23;--bad:#983f3b;--ok:#23573a;--font:'Avenir Next','Segoe UI',Arial,sans-serif;--mono:'SFMono-Regular',Consolas,'Liberation Mono',monospace}
:root[data-theme="light"]{--bg:#e8ede5;--page:#21342b;--card:#fffef9;--ink:#15231c;--muted:#53645b;--soft:#eaf0e7;--line:#d3dfd1;--input:#fff;--lime:#285d32;--sidebar:#f9fbf4;--side-border:#cbd8c9;--side-muted:#667c6d;--side-value:#2b6637;--button:#173026;--bad:#963d35;--ok:#255f33}
*{box-sizing:border-box}html{color-scheme:dark}html[data-theme="light"]{color-scheme:light}body{margin:0;min-width:320px;background:var(--bg);color:var(--page);font-family:var(--font);-webkit-font-smoothing:antialiased}button,input,textarea,select{font:inherit}button{cursor:pointer}a{color:inherit;text-decoration:none}button:disabled{opacity:.6;cursor:not-allowed}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #cba05c;outline-offset:2px}[hidden]{display:none!important}
.shell{width:min(100%,1440px);margin:auto;padding:14px clamp(13px,2.1vw,32px)}.game-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(235px,340px);gap:13px;align-items:stretch}
.challenge-card{height:min(570px,calc(100dvh - 28px));min-height:500px;padding:29px clamp(23px,3.1vw,45px) 28px;background:var(--card);color:var(--ink);border-radius:18px;display:flex;flex-direction:column;min-width:0;box-shadow:0 16px 42px rgba(0,0,0,.12)}
.card-toolbar{display:flex;align-items:center;gap:12px;flex:none}.micro-logo{font:950 21px/1 var(--font);letter-spacing:-1.4px;min-width:52px;color:var(--ink)}.micro-logo span{color:#7ca535}.difficulty-tabs{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:4px;padding:4px;border-radius:11px;background:var(--soft);border:1px solid var(--line);margin-left:auto;width:min(405px,75%)}.difficulty-tabs button{border:1px solid transparent;background:none;color:var(--muted);padding:9px 4px;min-height:37px;font:750 12px var(--mono);border-radius:8px}.difficulty-tabs button.active{background:var(--input);color:var(--ink);border-color:var(--line);box-shadow:0 2px 9px rgba(0,0,0,.07)}.difficulty-tabs button[data-level="easy"].active{border-bottom:2px solid #659765}.difficulty-tabs button[data-level="medium"].active{border-bottom:2px solid #c09954}.difficulty-tabs button[data-level="hard"].active{border-bottom:2px solid #be6c69}.done-mark{color:#679643;margin-left:4px}.icon-button{width:38px;height:38px;min-width:38px;padding:8px;display:grid;place-items:center;background:transparent;color:var(--ink);border:1px solid var(--line);border-radius:9px}.icon-button:hover{background:var(--soft)}.icon-button svg{width:20px;height:20px;stroke:currentColor;stroke-width:1.65;fill:none;stroke-linejoin:round;stroke-linecap:round}.toolbar-actions{display:flex;gap:6px}
.question-title{font-size:clamp(29px,3vw,42px);line-height:1.12;letter-spacing:-1.4px;margin:29px 0 13px;font-weight:850}.question-prompt{font-size:clamp(16px,1.4vw,19px);line-height:1.55;color:var(--muted);overflow:auto;min-height:30px;flex:1;scrollbar-width:thin;padding-right:2px;white-space:pre-wrap}.question-prompt strong{color:var(--ink)}
.answer-bottom{flex:none;border-top:1px solid var(--line);margin-top:19px;padding-top:17px;position:relative}.answer-form{display:flex;align-items:stretch;gap:9px}.answer-entry{flex:1;min-width:0;height:51px}.answer-input{width:100%;height:100%;border:1.5px solid #b5c7b5;border-radius:10px;background:var(--input);padding:0 15px;color:var(--ink);font:500 16px var(--mono);outline:none}.answer-input::placeholder{color:#8c9c90}.answer-input:focus,.stacked-fraction:focus-within{border-color:#80a269;box-shadow:0 0 0 3px #80a26924}.primary-button{min-height:44px;background:var(--button);color:#d8ff73;border:0;border-radius:10px;padding:0 18px;font:850 11px var(--mono);white-space:nowrap}.primary-button:hover{filter:brightness(1.16)}.answer-form .primary-button{height:51px;min-width:154px}
.stacked-fraction{height:51px;display:flex;flex-direction:column;align-items:center;justify-content:center;border:1.5px solid #b5c7b5;background:var(--input);border-radius:10px}.stacked-fraction input{display:block;width:min(250px,85%);height:21px;border:0;outline:none;text-align:center;color:var(--ink);background:transparent;font:500 15px var(--mono)}.stacked-fraction .bar{width:min(250px,85%);height:1.5px;background:var(--ink)}.stacked-fraction input::placeholder{color:#8d9d92;font-size:11px}
.feedback-space{height:27px;display:flex;align-items:center}.feedback{font:650 12px/1.35 var(--font);color:var(--bad)}.feedback.ok{color:var(--ok)}.hint-slots{display:grid;grid-template-columns:1fr;gap:7px}.hint-slot{height:43px;position:relative;overflow:hidden;display:flex;align-items:center;padding:8px 11px;border:1px solid var(--line);border-radius:8px;background:var(--soft);color:var(--muted);font-size:12px;line-height:1.3}.hint-index{font:850 10px var(--mono);color:var(--ink);margin-right:10px;flex:none}.hint-text{display:block;overflow-y:auto;max-height:38px}.hint-cover{position:absolute;inset:0;border:1px solid #95a996;background:#c6d3c1;color:#254134;text-align:left;padding:0 13px;border-radius:7px;font:780 11px var(--mono);display:flex;align-items:center;justify-content:space-between}.hint-cover:hover:not(:disabled){background:#b6caa9}.hint-cover:disabled{opacity:1;background:#d5dfd1;color:#819586}.hint-cover .plus{font-size:17px}.hint-cover[data-locked="true"]{cursor:not-allowed}.share-btn{border:0;border-radius:7px;background:var(--button);color:#d8ff73;font:750 11px var(--mono);padding:9px 13px}
.math-keyboard{position:absolute;right:0;bottom:calc(100% + 5px);width:min(490px,100%);z-index:20;border-radius:12px;padding:10px;background:#22313a;border:1px solid #43545d;box-shadow:0 18px 40px #0005;color:white}.keyboard-header{font:700 10px var(--mono);color:#b4c4c3;margin:0 0 8px;display:flex;justify-content:space-between;align-items:center}.keyboard-header button{background:none;color:white;border:0;font-size:18px}.keyboard-grid{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:5px}.keyboard-grid button{min-height:35px;padding:3px;border:1px solid #435763;background:#2d404a;border-radius:7px;color:#edf3ed;font:650 12px var(--mono)}.keyboard-grid button:hover{background:#415c64}.keyboard-grid button[data-key="frac"]{color:#d8ff73}.keyboard-footer{font-size:10px;color:#adbdc1;margin-top:8px}
.solved-bar{min-height:42px;display:flex;align-items:center;justify-content:space-between;background:#dcead7;color:#245335;border:1px solid #b6d8ac;border-radius:9px;padding:6px 11px;font:850 13px var(--mono)}.result-panel{flex:none;min-height:98px;margin-top:9px}.result-grid{display:flex;gap:9px;align-items:stretch}.result-stat{background:var(--soft);border:1px solid var(--line);border-radius:8px;padding:9px 11px;flex:1;min-width:0}.result-stat small{display:block;color:var(--muted);font:700 9px var(--mono);letter-spacing:.06em}.result-stat strong{font:850 19px var(--mono);color:var(--ink);margin-top:4px;display:block}.result-explain{font-size:10px;color:var(--muted);margin-top:6px}.curve-svg{width:100%;height:66px;max-width:260px;display:block}.curve-line{stroke:#4a7c55;stroke-width:2;fill:none}.curve-marker{stroke:#c46e42;stroke-width:2}.comment-section{display:flex;flex-direction:column;min-height:85px;flex:1;border-top:1px solid var(--line);padding-top:9px;margin-top:10px}.comment-title{font:800 11px var(--mono);margin:0 0 7px;color:var(--ink);display:flex;justify-content:space-between}.comment-list{overflow-y:auto;min-height:50px;max-height:116px;scrollbar-width:thin;flex:1}.comment{font-size:12px;color:var(--muted);padding:6px 0;border-bottom:1px solid var(--line);overflow-wrap:anywhere}.comment-header{font:800 10px var(--mono);color:var(--ink)}.comment-header em{font-style:normal;font-weight:600;color:var(--muted);margin-left:7px}.comment-body{margin:3px 0 0;white-space:pre-wrap}.comment-form{display:flex;gap:7px;margin-top:7px}.comment-form input{border:1px solid var(--line);border-radius:7px;background:var(--input);padding:8px 10px;flex:1;min-width:0;font-size:12px;color:var(--ink)}.comment-form button{border:0;border-radius:7px;background:var(--button);color:#d8ff73;padding:0 13px;font:800 10px var(--mono)}.comment-note{font-size:11px;color:var(--muted);margin:6px 0}
.side-column{height:min(570px,calc(100dvh - 28px));min-height:500px;display:flex;flex-direction:column;gap:10px;min-width:0}.side-panel,.account-panel{background:var(--sidebar);border:1px solid var(--side-border);border-radius:18px;color:var(--page)}.side-panel{flex:none;min-height:207px;padding:23px 28px}.side-label,.panel-kicker{font:800 11px var(--mono);letter-spacing:.12em;color:var(--side-muted)}.countdown-number{font:850 clamp(27px,2.3vw,37px) var(--mono);color:var(--side-value);letter-spacing:-1.5px;margin-top:12px;font-variant-numeric:tabular-nums}.side-line{height:1px;background:var(--side-border);margin:17px 0 17px}.streak-line{display:flex;align-items:baseline;gap:8px;margin-top:6px}.streak-line strong{font:850 40px/1 var(--mono);color:var(--side-value)}.streak-line span{font:650 11px var(--mono);color:var(--side-muted)}.account-panel{flex:1;min-height:0;padding:22px 24px;display:flex;flex-direction:column;gap:12px}.account-title{font-size:22px;font-weight:850;letter-spacing:-.5px}.account-content{flex:1;display:flex;flex-direction:column;gap:9px}.account-content small,.account-content p{font-size:11px;color:var(--side-muted);line-height:1.45;margin:0}.google-button{width:100%;border:1px solid #dce6dc;background:#fff;color:#27352d;border-radius:9px;padding:10px 9px;display:flex;align-items:center;justify-content:center;gap:9px;font-size:12px;font-weight:750;min-height:41px}.google-button:hover{background:#ecf3e8}.google-button svg{width:17px;height:17px}.account-status{font-size:11px;color:var(--side-muted);line-height:1.35}.profile-name{color:var(--page);font-size:14px;font-weight:760;overflow-wrap:anywhere}.nickname-form{display:flex;gap:6px}.nickname-form input{width:0;min-width:0;flex:1;background:transparent;border:1px solid var(--side-border);color:var(--page);border-radius:6px;padding:7px;font-size:11px}.nickname-form button,.small-link{border:1px solid var(--side-border);background:transparent;color:var(--side-value);border-radius:6px;font:700 10px var(--mono);padding:7px}.account-links{display:grid;gap:0;flex:none;border-top:1px solid var(--side-border)}.account-links a{display:flex;align-items:center;justify-content:space-between;padding:12px 0;font:750 12px var(--mono);border-bottom:1px solid var(--side-border)}.account-links a:hover{color:var(--side-value)}.account-links a:last-child{border:0}.account-links span{color:var(--side-value)}
.toast{position:fixed;left:50%;bottom:14px;transform:translateX(-50%);z-index:100;background:#d8ff73;color:#15221b;border-radius:8px;padding:10px 15px;font-size:12px;font-weight:750;max-width:92vw}#confetti{position:fixed;inset:0;width:100%;height:100%;pointer-events:none;z-index:101}
.loading{color:var(--muted);font-size:14px;margin:auto}.notice{padding:14px;border:1px solid var(--line);border-radius:9px;background:var(--soft);color:var(--muted);font-size:12px;line-height:1.5}.preview-flag{font:750 9px var(--mono);letter-spacing:.09em;color:#9b793b}
.subpage{max-width:980px}.subpage-header{display:flex;align-items:center;justify-content:space-between;margin:9px 0 18px}.back-link{font:750 12px var(--mono);color:var(--page)}.subpage-header .micro-logo{color:var(--page)}.page-panel{background:var(--card);border-radius:18px;color:var(--ink);padding:clamp(24px,4vw,48px)}.page-panel h1{font-size:clamp(33px,5vw,48px);line-height:1.12;letter-spacing:-1.6px;margin:10px 0}.page-kicker{font:760 11px var(--mono);color:var(--muted);letter-spacing:.08em}.page-sub{color:var(--muted);font-size:14px;line-height:1.5;max-width:680px;margin:0 0 25px}.archive-list{display:grid;gap:10px}.archive-day{font:800 12px var(--mono);color:var(--muted);margin-top:16px}.archive-item{border:1px solid var(--line);border-radius:9px;padding:15px;background:var(--input)}.archive-item summary{cursor:pointer;display:flex;gap:15px;align-items:center;justify-content:space-between;font-weight:780;font-size:15px}.archive-item summary span{font:760 10px var(--mono);color:var(--muted)}.archive-item p{white-space:pre-wrap;color:var(--muted);font-size:13px;line-height:1.6}.archive-locked{color:var(--muted);font-size:13px}.admin-panel{max-width:780px}.admin-lock{max-width:450px;display:grid;gap:9px}.admin-lock input,.studio-form input,.studio-form select,.studio-form textarea{width:100%;border:1px solid #bdcbbd;border-radius:8px;background:var(--input);color:var(--ink);padding:11px;font-size:13px}.admin-lock label,.studio-form label{font:730 11px var(--mono);color:var(--muted);display:grid;gap:6px}.form-status{font-size:12px;color:var(--bad)}.studio-form{display:grid;gap:14px}.studio-split{display:grid;grid-template-columns:1fr 1fr;gap:12px}.studio-form textarea{min-height:85px;resize:vertical;line-height:1.5}.studio-form .primary-button{justify-self:start}.studio-schedule{margin-top:24px;border-top:1px solid var(--line);padding-top:18px}.schedule-line{padding:7px 0;border-bottom:1px solid var(--line);font:650 12px var(--mono);color:var(--muted)}
@media(max-width:1060px){.challenge-card{padding:26px 26px}.side-panel{padding:24px 22px}.account-panel{padding:20px}.question-title{font-size:34px}.answer-form .primary-button{min-width:115px;padding:0 10px}.difficulty-tabs{width:min(370px,75%)} }
@media(max-width:790px){.shell{padding:12px}.game-grid{grid-template-columns:1fr;gap:12px}.challenge-card{height:auto;min-height:550px;max-height:none;padding:26px}.question-prompt{flex:none;overflow:visible;max-height:none;min-height:90px}.answer-bottom{margin-top:auto}.side-column{height:auto;min-height:0;gap:12px}.side-panel{min-height:0;padding:18px 23px;display:grid;grid-template-columns:1fr 1px 1fr;align-items:center;gap:17px}.side-panel .side-line{width:1px;height:55px;margin:0;grid-column:2;grid-row:1/3}.side-panel .side-label:first-child{grid-column:1;grid-row:1}.countdown-number{grid-column:1;grid-row:2}.side-panel .side-label:nth-of-type(4){grid-column:3;grid-row:1}.streak-line{grid-column:3;grid-row:2}.countdown-number{font-size:27px;margin:0}.streak-line{margin:0}.account-panel{min-height:160px;gap:12px}.account-content{gap:8px}.account-links{grid-template-columns:1fr 1fr;gap:18px}.account-links a{white-space:nowrap}.comment-list{max-height:160px}.comment-section{flex:auto}.result-panel{flex:auto} }
@media(max-width:500px){.challenge-card{min-height:475px;border-radius:14px;padding:20px 18px}.card-toolbar{gap:6px}.micro-logo{font-size:17px;min-width:35px}.difficulty-tabs{gap:1px;padding:3px;width:100%}.difficulty-tabs button{font-size:10px;min-height:35px;padding:5px 3px}.icon-button{width:34px;min-width:34px;height:34px;padding:7px}.icon-button svg{width:17px;height:17px}.toolbar-actions{gap:4px}.question-title{font-size:clamp(27px,7.6vw,35px);margin:23px 0 13px}.question-prompt{font-size:16px;line-height:1.5}.answer-bottom{padding-top:13px;margin-top:20px}.answer-entry,.answer-form .primary-button{height:46px}.answer-form{gap:7px}.answer-form .primary-button{font-size:9px;min-width:100px}.answer-input{font-size:14px;padding:0 10px}.hint-slot{height:45px}.side-panel{gap:10px;padding:17px 16px}.countdown-number{font-size:22px}.streak-line strong{font-size:34px}.side-label{font-size:9px}.account-panel{padding:17px 19px}.account-title{font-size:20px}.keyboard-grid{grid-template-columns:repeat(6,minmax(0,1fr))}.math-keyboard{width:min(355px,calc(100vw - 40px))}.result-stat strong{font-size:15px}.result-panel{min-height:85px}.page-panel{padding:22px 17px}.studio-split{grid-template-columns:1fr}}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}
/* Keep the full results and discussion inside the fixed-height challenge card. */
.challenge-card{padding-bottom:22px}
.result-panel{margin-top:6px;min-height:0}
.result-explain{font-size:9px;margin-top:3px}
.comment-section{margin-top:6px;padding-top:6px;min-height:0}
.comment-list{min-height:24px;max-height:90px}
.comment-form{margin-top:4px}
.comment-form input{padding:6px 9px}
.challenge-card.is-solved .question-prompt{flex:0 1 auto;max-height:120px;min-height:0;overflow-y:auto}
.challenge-card.is-solved .comment-section{flex:1}
@media(max-width:790px){.challenge-card.is-solved .question-prompt{max-height:none;overflow:visible}}


/* Developer-only navigation is hidden until the database confirms authorization. */
.account-links a[hidden], .studio-danger[hidden], .studio-submissions[hidden] {display:none!important}

/* Locked collection view. No archive data is downloaded on this page. */
.archive-locked-panel {min-height:540px;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:48px 32px}
.archive-lock-visual {display:grid;place-items:center;width:106px;height:106px;border-radius:26px;background:var(--soft);border:1px solid var(--line);color:var(--ink);margin:30px auto 18px;box-shadow:0 14px 35px rgba(0,0,0,.045)}
.archive-lock-visual svg {width:52px;height:52px}
.archive-locked-panel h1 {font-size:clamp(42px,6vw,68px);letter-spacing:-2.5px}
.archive-locked-panel .page-sub {max-width:470px;margin:12px auto 24px;font-size:15px}
.archive-locked-actions {display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:14px}
.archive-locked-chip,.archive-back-button {font:760 11px var(--mono);letter-spacing:.05em;border-radius:8px;padding:12px 15px}
.archive-locked-chip {color:var(--muted);border:1px solid var(--line);background:var(--soft)}
.archive-back-button {background:var(--button);color:#d8ff73;text-decoration:none}
.archive-back-button:hover {filter:brightness(1.13)}

/* Protected developer question manager */
.subpage:has(.admin-panel) {max-width:1220px}
.admin-panel {max-width:none}
.admin-panel>h1 {margin-top:13px}
.studio-top {display:flex;align-items:center;justify-content:space-between;gap:20px;margin:30px 0 20px;padding-top:24px;border-top:1px solid var(--line)}
.studio-top h2 {font-size:27px;line-height:1.15;letter-spacing:-.8px;margin:5px 0 8px}
.studio-help {font-size:12px;line-height:1.55;color:var(--muted);max-width:640px;margin:6px 0 0}
.studio-secondary {padding:11px 16px;background:var(--soft);border:1px solid var(--line);border-radius:9px;color:var(--ink);font:750 11px var(--mono);white-space:nowrap;cursor:pointer}
.studio-secondary:hover {border-color:var(--muted)}
.studio-workspace {display:grid;grid-template-columns:minmax(255px,.84fr) minmax(0,1.65fr);align-items:start;gap:22px}
.studio-browser {border:1px solid var(--line);border-radius:14px;background:var(--soft);padding:17px;min-width:0}
.studio-search-label {display:block;font:750 11px var(--mono);color:var(--muted);margin:0 0 8px}
#studio-filter {display:block;width:100%;min-width:0;border-radius:8px;border:1px solid var(--line);background:var(--input);color:var(--ink);padding:11px;font-size:12px}
.studio-count {font:720 10px var(--mono);color:var(--muted);margin:13px 0 10px}
.studio-question-list {display:grid;gap:8px;overflow:auto;max-height:min(70vh,740px);scrollbar-width:thin}
.studio-question-item {display:grid;gap:6px;min-width:0;width:100%;text-align:left;border-radius:9px;border:1px solid var(--line);background:var(--input);color:var(--ink);padding:12px;cursor:pointer}
.studio-question-item:hover {border-color:var(--muted)}
.studio-question-item.selected {outline:2px solid var(--button);outline-offset:0;border-color:var(--button)}
.studio-item-date {font:750 10px var(--mono);color:var(--muted);letter-spacing:.04em}
.studio-item-title {display:block;font:780 13px var(--sans,system-ui);overflow-wrap:anywhere}
.studio-item-footer {display:flex;justify-content:space-between;gap:5px;align-items:center;font:620 9px var(--mono);color:var(--muted)}
.studio-detail {min-width:0}
.studio-detail-head {display:flex;align-items:end;justify-content:space-between;gap:10px;margin-bottom:18px}
.studio-detail-head h3 {font-size:23px;line-height:1.2;letter-spacing:-.6px;margin:4px 0 0;overflow-wrap:anywhere}
.studio-status-pill {font:750 10px var(--mono);color:var(--muted);border:1px solid var(--line);background:var(--soft);padding:7px 9px;border-radius:7px;white-space:nowrap}
.studio-form {display:grid;gap:13px}
.studio-form label {font:730 11px var(--mono);color:var(--muted);display:grid;gap:7px}
.studio-form input,.studio-form select,.studio-form textarea {display:block;width:100%;min-width:0;border:1px solid #bdcbbd;border-radius:8px;background:var(--input);color:var(--ink);padding:11px;font:500 13px/1.45 system-ui,sans-serif}
.studio-form textarea {resize:vertical;min-height:80px}
.studio-form textarea[name=prompt] {min-height:115px}
.studio-split {display:grid;grid-template-columns:1fr 1fr;gap:12px;min-width:0}
.studio-check {display:flex!important;align-items:start;gap:12px!important;padding:14px;border:1px solid var(--line);background:var(--soft);border-radius:10px;cursor:pointer}
.studio-check input {width:17px!important;height:17px!important;flex:0 0 17px;margin:1px 0 0;accent-color:var(--button)}
.studio-check span {display:grid;gap:4px}
.studio-check strong {font:800 11px var(--mono);color:var(--ink)}
.studio-check small {font:500 11px/1.5 system-ui,sans-serif;color:var(--muted)}
.studio-actions {display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-top:2px}
.studio-actions .primary-button {min-width:160px;padding:12px 19px;cursor:pointer}
.studio-danger {border:1px solid #c47769;border-radius:8px;background:transparent;color:#ac4c3d;padding:11px 14px;font:790 11px var(--mono);cursor:pointer}
.studio-danger:hover {background:#fff0ed}
.studio-feedback {font-size:12px;line-height:1.5;color:#347650;margin:0;min-height:18px}
.studio-feedback.is-error {color:#ad493d}
.studio-submissions {margin-top:30px;padding-top:19px;border-top:1px solid var(--line)}
.studio-section-head {display:flex;align-items:center;justify-content:space-between;gap:10px}
.studio-section-head h3 {font-size:18px;margin:0}
.studio-section-head span {font:700 10px var(--mono);color:var(--muted)}
.studio-attempt-list {display:grid;gap:7px;margin-top:15px}
.studio-attempt {display:flex;align-items:center;justify-content:space-between;gap:14px;border:1px solid var(--line);border-radius:9px;padding:11px 13px}
.studio-attempt strong {font-size:12px;font-weight:800;overflow-wrap:anywhere}
.studio-attempt p {font:650 10px/1.5 var(--mono);color:var(--muted);margin:5px 0 0}
.studio-attempt-state {font:700 9px var(--mono);color:var(--muted)}
.studio-attempt-remove {background:transparent;border:1px solid #ca8d85;color:#a64238;border-radius:7px;padding:7px 10px;font:750 10px var(--mono);cursor:pointer}
.studio-empty {margin:8px 0;color:var(--muted);font:600 12px/1.5 var(--mono)}
.studio-form button:disabled {cursor:wait;opacity:.55}

@media(max-width:850px){
 .studio-workspace {grid-template-columns:1fr}
 .studio-question-list {max-height:300px}
 .studio-top {align-items:flex-start}
}
@media(max-width:500px){
 .studio-top {flex-direction:column;align-items:stretch}
 .studio-top .studio-secondary {align-self:flex-start}
 .studio-split {grid-template-columns:1fr}
 .archive-locked-panel {min-height:480px;padding:34px 16px}
 .archive-locked-panel h1 {letter-spacing:-1.7px}
 .studio-detail-head {align-items:flex-start;flex-direction:column}
}

@media(max-width:790px){.account-links:has(> #developer-access-link[hidden]){grid-template-columns:1fr}}


/* Private results: no public rank or solver totals. */
.result-grid-private{display:grid;grid-template-columns:repeat(2,minmax(0,1fr))}
.result-grid-waiting{display:grid;grid-template-columns:minmax(100px,.6fr) minmax(0,2fr)}
.result-waiting strong{font:750 12px/1.35 var(--font);letter-spacing:0}
.result-small{display:block;color:var(--muted);font-size:10px;line-height:1.35;margin-top:5px}
.result-curve-row{display:flex;align-items:flex-start;gap:12px;max-width:100%;margin-top:6px}
.result-model-flag{font:800 9px var(--mono);letter-spacing:.06em;color:var(--muted);border:1px solid var(--line);border-radius:5px;padding:5px;flex-shrink:0}
.result-disclosure{font-weight:650}

/* Safe KaTeX rendering: readable on desktop and small screens. */
.question-prompt .katex-display,
.hint-text .katex-display,
.studio-math-preview .katex-display{max-width:100%;overflow-x:auto;overflow-y:hidden;padding:5px 0}
.question-prompt .katex{font-size:1.08em}
.hint-text .katex{font-size:1em}
.question-prompt .katex-html{white-space:normal}
.studio-math-preview{border:1px solid var(--line);background:var(--soft);padding:16px;border-radius:11px;overflow:hidden}
.studio-math-preview .page-kicker{margin-bottom:12px}
.studio-preview-content{background:var(--input);padding:15px;border:1px solid var(--line);border-radius:8px;max-width:100%;color:var(--ink);overflow-wrap:anywhere}
.studio-preview-content h4{font-size:17px;line-height:1.3;margin:0 0 10px}
.studio-preview-prompt{white-space:pre-wrap;line-height:1.6;font-size:14px;margin:0}
.studio-preview-hints{border-top:1px solid var(--line);margin-top:14px;padding-top:11px;display:grid;gap:5px}
.studio-preview-hints strong{font:800 10px var(--mono);color:var(--muted)}
.studio-preview-hints p{font:500 12px/1.5 var(--font);white-space:pre-wrap;margin:0 0 8px}
.studio-preview-guide{color:var(--muted);font:650 11px/1.6 var(--mono);margin:10px 0 0;overflow-wrap:anywhere}
@media(max-width:500px){
 .result-grid-waiting{grid-template-columns:1fr}
 .result-curve-row{flex-wrap:wrap;gap:5px}
 .result-model-flag{font-size:8px}
 .studio-math-preview{padding:11px}
}


/* Private revision history */
.studio-history{border-top:1px solid var(--line);margin-top:25px;padding-top:20px}
.studio-history-list{display:grid;gap:8px;margin-top:15px;max-height:450px;overflow-y:auto}
.studio-history-event{border:1px solid var(--line);border-radius:9px;background:var(--soft);overflow:hidden}
.studio-history-event summary{display:flex;gap:12px;align-items:center;justify-content:space-between;cursor:pointer;padding:12px;font:700 10px var(--mono);color:var(--muted)}
.studio-history-kind{color:var(--ink);font-weight:850;overflow-wrap:anywhere}
.studio-history-json{margin:0;max-height:360px;overflow:auto;font:500 11px/1.5 var(--mono);white-space:pre-wrap;overflow-wrap:anywhere;background:var(--input);padding:12px;color:var(--ink)}

/* Standalone input lab: does not affect the production answer field. */
.math-lab-page{max-width:950px}
.math-lab-page .page-panel{max-width:none}
.math-lab-page h1{font-size:clamp(40px,5vw,62px);line-height:1.1}
.lab-console{border:1px solid var(--line);background:var(--soft);padding:22px;border-radius:14px;margin-top:25px;display:grid;gap:12px;color:var(--ink)}
.lab-console>label{font:800 11px var(--mono);color:var(--muted)}
.lab-console math-field{display:block;width:100%;min-height:92px;padding:20px 16px;background:var(--input);border:2px solid var(--line);border-radius:12px;font-size:28px;line-height:1.3;color:var(--ink);overflow-x:auto;--caret-color:var(--ink);--selection-background-color:#bedbba}
.lab-console math-field:focus-within{border-color:#78a47a;outline:3px solid #78a47a33}
.lab-buttons,.lab-examples{display:flex;flex-wrap:wrap;gap:8px}
.lab-buttons button,.lab-examples button,.lab-inspection button{background:var(--input);border:1px solid var(--line);padding:10px 12px;border-radius:8px;color:var(--ink);font:750 11px var(--mono);cursor:pointer}
.lab-buttons button:hover,.lab-examples button:hover,.lab-inspection button:hover{border-color:var(--muted)}
.lab-caption{font:800 10px var(--mono);color:var(--muted);margin:8px 0 0}
.lab-inspection{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:15px;border:1px solid var(--line);background:var(--input);border-radius:10px}
.lab-inspection>div{min-width:0;flex:1;display:grid;gap:6px}
.lab-inspection strong{font:800 10px var(--mono);color:var(--muted)}
.lab-inspection code{display:block;font:500 12px/1.5 var(--mono);white-space:pre-wrap;overflow-wrap:anywhere}
.lab-status{font-size:11px;color:var(--muted);margin:0}
.lab-disclaimer{border-left:3px solid #7b9f72;padding:12px 14px;margin-top:18px;font-size:12px;line-height:1.6;color:var(--muted)}
.lab-disclaimer strong{color:var(--ink)}
@media(max-width:540px){.lab-console{padding:12px}.lab-console math-field{min-height:77px;padding:15px 10px;font-size:23px}.lab-inspection{align-items:stretch;flex-direction:column}}


/* Natural, MathLive-powered answer input. Text input remains as a fallback. */
.answer-form.mathlive-active{align-items:stretch}
.mathlive-active .answer-entry{height:auto;min-height:51px}
.mathlive-active #answer-input,
.mathlive-active #stacked-fraction{display:none!important}
.answer-mathfield{display:block;box-sizing:border-box;width:100%;min-height:51px;max-height:100px;
  overflow-y:auto;overflow-x:auto;padding:9px 12px;font-size:21px;line-height:1.3;
  border:1.5px solid #b5c7b5;border-radius:10px;background:var(--input);color:var(--ink)}
.answer-mathfield:focus-within{border-color:#80a269;outline:3px solid #80a26924}
.answer-bottom:has(.mathlive-active) #math-keyboard{display:none!important}
.answer-mathfield::part(virtual-keyboard-toggle),
#lab-field::part(virtual-keyboard-toggle){display:none}
.answer-evaluation{font:700 11px/1.4 var(--mono);color:var(--ok);margin:6px 0 -4px;overflow-wrap:anywhere}
.answer-evaluation.is-invalid{color:var(--muted)}
.answer-bottom:has(.mathlive-active){overflow:visible}
.lab-result{display:flex;align-items:baseline;gap:12px;min-height:69px;background:var(--input);
  border:1px solid var(--line);border-radius:10px;padding:14px 17px;color:var(--ink)}
.lab-result-equals{font-size:28px;font-weight:600;color:var(--muted)}
#lab-result-number{font:780 clamp(20px,3vw,34px)/1.2 var(--mono);overflow-wrap:anywhere}
#lab-result-number.has-error{color:var(--muted)}
.lab-console .lab-status{font:600 12px/1.5 var(--mono);min-height:18px}
@media(max-width:600px){
  .answer-form.mathlive-active{flex-wrap:wrap}
  .answer-form.mathlive-active .answer-entry{flex:1 0 100%;width:100%}
  .answer-form.mathlive-active .primary-button{width:100%}
  .answer-mathfield{font-size:19px}
  .lab-result{min-height:60px}
}


/* Crawlable public site information — same design tokens as the challenge UI. */
.site-intro{margin-top:7px}
.site-intro-content{background:var(--sidebar);color:var(--page);border:1px solid var(--side-border);
  border-radius:15px;padding:clamp(20px,3vw,34px);max-width:none}
.site-intro-kicker{font:800 10px/1.5 var(--mono);letter-spacing:.09em;color:var(--side-muted);margin:0 0 8px}
.site-intro h2{font-size:clamp(22px,3vw,32px);font-weight:850;letter-spacing:-.9px;margin:0 0 9px}
.site-intro p:not(.site-intro-kicker){font:500 13px/1.65 var(--font);color:var(--side-muted);max-width:790px;margin:0 0 13px}
.site-intro-about{font:800 11px var(--mono);color:var(--side-value);text-decoration:underline;text-underline-offset:3px}
.site-intro-about:hover{filter:brightness(1.13)}

.site-footer{margin-top:9px;padding-top:23px;padding-bottom:35px;display:flex;gap:12px 30px;
  align-items:center;justify-content:space-between;flex-wrap:wrap;
  color:var(--page);border-top:1px solid var(--side-border)}
.site-footer-brand{font:750 11px/1.5 var(--mono)}
.site-footer nav{display:flex;gap:13px 20px;align-items:center;flex-wrap:wrap}
.site-footer nav a,.site-footer-contact a{font:700 11px/1.5 var(--mono);
  text-decoration:underline;text-underline-offset:3px}
.site-footer-contact{font:500 11px/1.5 var(--mono);color:var(--side-muted);overflow-wrap:anywhere}
.site-footer a:hover,.trust-text-link:hover{text-decoration-thickness:2px}

.public-content{max-width:1020px}
.trust-page-panel{max-width:none;padding:clamp(25px,4vw,55px)}
.trust-page-panel h1{font-size:clamp(36px,5vw,62px);max-width:800px;letter-spacing:-2px}
.trust-lead{font:550 clamp(16px,2.1vw,20px)/1.55 var(--font);color:var(--ink);
  max-width:740px;margin:14px 0 24px}
.trust-page-panel p:not(.trust-lead):not(.trust-updated),
.trust-page-panel li{font:460 14px/1.8 var(--font);color:var(--muted)}
.trust-page-panel h2{font-size:clamp(18px,2vw,23px);margin:30px 0 9px;font-weight:830;
  letter-spacing:-.4px;color:var(--ink)}
.trust-page-panel ul{padding-left:20px;display:grid;gap:10px}
.trust-page-panel li strong{color:var(--ink)}
.trust-page-panel a{overflow-wrap:anywhere}
.trust-text-link{color:var(--ink);font-weight:750;text-decoration:underline;text-underline-offset:2px}
.trust-updated{color:var(--muted);font:720 11px var(--mono);margin:4px 0 22px}
.trust-feature-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;
  margin:30px 0;padding:0}
.trust-feature{border:1px solid var(--line);background:var(--soft);border-radius:12px;
  padding:19px;min-width:0}
.trust-feature-number{font:800 11px var(--mono);color:var(--muted)}
.trust-feature h2{font-size:16px;line-height:1.3;margin:13px 0 6px}
.trust-feature p{font-size:12px!important;line-height:1.65!important;margin:0}
.trust-actions{display:flex;gap:12px;flex-wrap:wrap;align-items:center;margin-top:25px}
.trust-primary-link,.trust-secondary-link{display:inline-flex;align-items:center;justify-content:center;
  border-radius:9px;padding:13px 17px;font:800 11px var(--mono)}
.trust-primary-link{background:var(--button);color:#d8ff73}
.trust-secondary-link{background:var(--soft);color:var(--ink);border:1px solid var(--line)}
.trust-contact-card{border:1px solid var(--line);background:var(--soft);padding:clamp(16px,3vw,28px);
  border-radius:14px;display:grid;justify-items:start;gap:10px;margin:25px 0}
.trust-email{font:850 clamp(18px,3vw,27px)/1.3 var(--font);color:var(--ink);
  text-decoration:underline;text-underline-offset:4px;overflow-wrap:anywhere}
.trust-contact-card p{margin:0 0 7px}
.trust-independent-note{border-top:1px solid var(--line);padding-top:18px;margin-top:25px}
@media(max-width:750px){
  .trust-feature-grid{grid-template-columns:1fr}
  .trust-feature{padding:16px}
  .site-footer{align-items:flex-start;flex-direction:column}
  .site-intro-content{padding:22px}
}


/* Dedicated, crawlable educational guides. Landing page styles stay untouched. */
.guide-index .guide-topic-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px;margin:26px 0 36px}
.guide-topic{display:flex;flex-direction:column;gap:10px;background:var(--soft);border:1px solid var(--line);
  border-radius:12px;padding:clamp(17px,2.4vw,25px);color:var(--ink);min-width:0;text-decoration:none;
  transition:transform .16s ease,border-color .16s ease}
.guide-topic:hover{border-color:#6f9274;transform:translateY(-2px)}
.guide-topic-label{font:800 10px var(--mono);color:var(--muted);text-transform:uppercase;letter-spacing:.07em}
.guide-index .guide-topic h2{font:850 clamp(17px,2vw,23px)/1.2 var(--font);margin:1px 0 0}
.guide-index .guide-topic p{font:500 13px/1.6 var(--font);margin:0;color:var(--muted)}
.guide-topic-action{font:800 11px var(--mono);color:var(--ok);margin-top:auto;padding-top:8px}
.guide-article .trust-lead{max-width:790px}
.guide-breadcrumb{display:flex;align-items:center;gap:8px;flex-wrap:wrap;color:var(--muted);font:700 11px var(--mono);margin-bottom:25px}
.guide-breadcrumb a{text-decoration:underline;text-underline-offset:3px}
.guide-breadcrumb span[aria-current=page]{color:var(--ink)}
.guide-article h1{max-width:900px}
.guide-byline{font:700 11px/1.6 var(--mono)!important;color:var(--muted);border-bottom:1px solid var(--line);
  padding-bottom:20px;margin-bottom:28px}
.guide-body{max-width:850px}
.guide-body h2{scroll-margin-top:25px}
.guide-body p{max-width:77ch}
.guide-equation{display:block;max-width:100%!important;padding:15px 17px;margin:15px 0 20px!important;
  overflow-x:auto;border:1px solid var(--line);border-radius:8px;background:var(--soft);
  color:var(--ink)!important;font:650 clamp(13px,1.75vw,17px)/1.75 var(--mono)!important;
  font-variant-numeric:tabular-nums;overflow-wrap:anywhere}
.guide-equation strong{font-weight:900}
.guide-table-wrap{max-width:100%;overflow-x:auto;margin:18px 0 23px}
.guide-table{min-width:440px;width:100%;border-collapse:collapse;color:var(--ink);font-size:13px;text-align:left}
.guide-table caption{caption-side:top;text-align:left;font:760 11px/1.5 var(--mono);
  color:var(--muted);padding-bottom:9px}
.guide-table th,.guide-table td{padding:12px 10px;border:1px solid var(--line);vertical-align:top}
.guide-table thead{background:var(--soft)}
.guide-table tbody tr:nth-child(even){background:var(--input)}
.guide-table tfoot{font-weight:800;background:var(--soft)}
.guide-steps{padding-left:24px}
.guide-body ul,.guide-body ol{display:grid;gap:9px;margin:15px 0 24px;padding-left:23px}
.guide-body li{max-width:75ch}
.guide-body a{color:var(--ink);font-weight:750;text-decoration:underline;text-underline-offset:3px}
.guide-answer{border:1px solid var(--line);border-radius:10px;background:var(--soft);padding:15px 18px;margin:18px 0}
.guide-answer summary{cursor:pointer;font:800 13px var(--mono);color:var(--ink)}
.guide-answer[open] summary{margin-bottom:10px}
.guide-answer p{margin:0}
.guide-further-reading{font-size:12px!important;color:var(--muted)!important;border-left:3px solid #799c75;
  padding:12px 15px;margin:26px 0!important;background:var(--soft);max-width:100%!important}
.guide-next{border-top:1px solid var(--line);margin-top:33px;padding-top:20px}
.guide-related-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;margin:15px 0}
.guide-related-grid a{border:1px solid var(--line);background:var(--soft);border-radius:10px;
  display:grid;align-content:space-between;gap:13px;padding:15px;color:var(--ink);min-width:0}
.guide-related-grid a:hover{border-color:#6f9274}
.guide-related-grid strong{font-size:13px;line-height:1.4;overflow-wrap:anywhere}
.guide-related-grid span{font:800 10px var(--mono);color:var(--muted)}
@media(max-width:720px){
 .guide-index .guide-topic-grid{grid-template-columns:1fr}
 .guide-related-grid{grid-template-columns:1fr}
 .guide-topic:hover{transform:none}
 .guide-equation{padding:12px 13px}
 .guide-article h1{font-size:clamp(31px,7.8vw,44px)}
}
@media(prefers-reduced-motion:reduce){.guide-topic{transition:none}}