:root{color-scheme:light;--bg:#f4f5ef;--ink:#20372f;--muted:#728078;--green:#187963;--mint:#dff2e9;--orange:#d76736;--purple:#8b74b8;--line:#dce3db;font-family:-apple-system,BlinkMacSystemFont,"Noto Sans TC","PingFang TC",sans-serif;font-synthesis:none}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);min-width:280px}button,a,math-field{-webkit-tap-highlight-color:transparent}button{font:inherit;cursor:pointer;min-height:44px;border:0;border-radius:12px;background:#fff;color:var(--ink);padding:9px 13px;touch-action:manipulation}button:focus-visible,a:focus-visible{outline:3px solid #db9a54;outline-offset:3px}button:hover{filter:brightness(.96)}button:disabled{opacity:.4;cursor:default}button[hidden],[hidden]{display:none!important}.shell{max-width:1040px;margin:auto;padding:26px 30px 16px}.top{display:flex;align-items:center;justify-content:space-between;margin-bottom:22px}.brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none;font-weight:800;letter-spacing:1px;font-size:20px}.brand-icon{width:38px;height:38px;color:var(--green)}.brand-sub{display:block;font-weight:400;font-size:10px;color:var(--muted);letter-spacing:1.6px;margin-top:3px}.quiet{background:transparent;font-size:12px;color:var(--muted)}.top .quiet{background:#e8ece4;min-height:38px;padding:6px 13px}#progress{display:flex;gap:7px;margin-bottom:24px;counter-reset:step}#progress span{display:flex;flex:1;align-items:center;gap:8px;font-size:12px;line-height:1.3;color:#91a095;padding:10px 11px;background:#e9ede5;border-radius:9px;counter-increment:step}#progress span::before{content:counter(step);font-weight:700;font-variant-numeric:tabular-nums}#progress .current{color:#fff;background:var(--green);box-shadow:0 3px 9px #18796318}#progress .done{color:var(--green);background:#deebe1}.eyebrow{color:var(--green);letter-spacing:1px;font-size:11px;font-weight:600}h1{font-size:34px;margin:6px 0 8px;letter-spacing:1px}p{line-height:1.65}.mission>p{color:#647268;margin:0 0 18px;font-size:15px}.play-area{display:contents}.field{border:1px solid #d7e0d6;border-radius:20px;overflow:hidden;background:#fff;box-shadow:0 8px 22px #25453606}.field-top,.field-bottom{display:flex;align-items:center;gap:10px;color:var(--muted);font-size:10px;padding:12px 16px}.field-top{padding-bottom:0}.field-title{font-weight:600;letter-spacing:1px}.scale-note{margin-left:auto;font-size:9px}.dot{display:inline-block;width:6px;height:6px;border-radius:50%;margin-right:5px;vertical-align:middle}.cyan{background:var(--green)}.purple{background:var(--purple)}#board{display:block;width:100%;height:auto;aspect-ratio:380/360}#board text{font-family:inherit;font-size:10px;fill:#8a9b90}#board .point-label{fill:var(--orange);font-size:12px;font-weight:700}#board .cannon-label{fill:var(--green);font-size:11px;font-weight:600}.field-bottom{padding-top:0;justify-content:space-between;gap:6px;min-height:28px}.field-bottom span:first-child{color:var(--green);font-size:10px}.legend{white-space:nowrap}.console{min-width:0}.answer-heading{display:flex;justify-content:space-between;align-items:center;margin-bottom:4px}.answer-heading label{font-size:13px;font-weight:700;letter-spacing:1px}.answer-heading .quiet{padding:0 6px;min-height:32px;color:#6b8174}.answer-row{display:flex;gap:6px;align-items:center;padding:5px 6px 5px 12px;background:#fff;border:1.5px solid #cdd9cd;border-radius:14px;min-height:68px;box-shadow:0 3px 6px #213b2903}.answer-row:focus-within{border-color:var(--green);box-shadow:0 0 0 3px #1879630b}.equals{font-size:22px;font-family:Georgia,serif;font-style:italic;white-space:nowrap}.answer-row>#clear{color:#849087;background:transparent;font-size:10px;padding:5px;min-width:34px}math-field{display:block;background:transparent;color:var(--ink);min-width:0;flex:1;border:0;font-size:27px;--caret-color:var(--green);--selection-background-color:#adddcb88;--placeholder-color:#c1ccc2;--contains-highlight-background-color:transparent;--smart-fence-color:var(--green);padding:0}math-field::part(virtual-keyboard-toggle),math-field::part(menu-toggle){display:none}math-field::part(container){padding:3px 0}math-field:focus-within{outline:none}.input-status{font-size:10px;min-height:16px;color:var(--muted);margin:5px 2px 6px;line-height:1.5}.input-status.error{color:#b66136}.action-row{margin-bottom:12px;min-height:30px;display:flex;align-items:center}.action-row p{margin:0;font-size:12px;color:#64786a;line-height:1.5}.action-row p.success{color:var(--green);font-weight:600}.primary{background:var(--green);color:#fff;font-weight:700;min-width:86px;min-height:50px;padding-inline:13px;border-radius:10px;white-space:nowrap;box-shadow:0 3px 0 #0f5b49}.primary:disabled{box-shadow:none;opacity:.35}.primary:hover{background:#156c58}#next{font-size:12px;min-width:92px}#keypad{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:7px}#keypad button{font-size:20px;min-width:0;height:46px;padding:4px;background:#fff;border:1px solid #e0e7dc;border-bottom:3px solid #d5dfd2;border-radius:10px;font-variant-numeric:tabular-nums;box-shadow:0 2px 1px #33462a02}#keypad button:active{transform:translateY(1px);border-bottom-width:1px}#keypad button.operator{color:var(--green);background:#e4eee3;border-color:#d5e2d3;border-bottom-color:#c6d9c2}#keypad button.edit{font-size:18px;color:#7b8d7e;background:#eaf0e7;border-color:#e0e8dc;border-bottom-color:#d4dfcf}#keypad .fraction{display:inline-flex;flex-direction:column;font-size:13px;line-height:1.1;vertical-align:middle;padding:0 6px}#keypad .fraction span:first-child{border-bottom:1px solid currentColor;margin-bottom:2px;padding-bottom:1px}.keyboard-note{font-size:10px;color:#8a9a8d;margin-top:11px;text-align:center}footer{display:flex;justify-content:space-between;color:#98a495;font-size:10px;margin:20px 0 0;gap:10px}dialog{background:var(--bg);color:var(--ink);border:1px solid var(--line);border-radius:22px;max-width:min(90vw,420px);padding:28px;box-shadow:0 20px 100px #1c3a2930}dialog::backdrop{background:#1b392a70;backdrop-filter:blur(5px)}dialog h2{font-size:23px}dialog p{color:#64776a;font-size:15px}dialog .primary{margin-top:8px}.dialog-actions{display:flex;gap:8px;align-items:baseline}.ML__keyboard{display:none!important}
@media(min-width:800px){.shell{display:grid;grid-template-columns:1.18fr 1fr;column-gap:36px}.top,#progress,footer{grid-column:1/-1}.mission{grid-column:1/-1;grid-row:3;padding:0 0 10px}.mission>p{margin-bottom:12px}.field{grid-column:1;grid-row:4;align-self:start}.console{grid-column:2;grid-row:4;padding-top:8px}.answer-row{min-height:80px}.action-row{min-height:53px}.answer-heading{margin-bottom:9px}#keypad button{height:55px}.keyboard-note{margin-top:15px}.field-bottom{min-height:34px}.mission h1{font-size:32px}.mission .eyebrow{font-size:10px}footer{margin-top:23px}}
/* Mobile layout follows the actual Safari visual viewport, including toolbars. */
@media(max-width:799px){
 html{height:100%;overflow:hidden}body{position:fixed;inset:0;height:100%;overflow:hidden}
 .shell{max-width:460px;height:var(--play-height,100dvh);padding:7px 10px max(7px,env(safe-area-inset-bottom));display:grid;grid-template-rows:44px 4px auto minmax(80px,1fr) auto;gap:5px;overflow:hidden}
 .top{grid-row:1;margin:0;min-height:0}.brand{font-size:16px;gap:7px}.brand-icon{width:30px;height:30px}.brand-sub{display:none}.top-actions{display:flex;gap:3px}.top .quiet{min-height:44px;min-width:44px;font-size:11px;padding:4px 9px;background:transparent}
 #progress{grid-row:2;gap:5px;margin:0;height:4px}#progress span{padding:0;font-size:0;height:4px;border-radius:4px}#progress span::before{display:none}
 .mission{grid-row:3;display:grid;grid-template-columns:auto 1fr;column-gap:8px;align-items:center}.eyebrow{grid-column:1/-1;font-size:8px;line-height:12px;letter-spacing:.3px}h1{font-size:20px;line-height:25px;margin:0}.mission>p{margin:0;font-size:11px;line-height:1.4}
 .field{grid-row:4;min-height:0;display:grid;grid-template-rows:18px minmax(0,1fr) 18px;border-radius:13px;box-shadow:none}.field-top,.field-bottom{min-height:0;padding:1px 10px;font-size:8px;gap:5px;overflow:hidden}.field-title{letter-spacing:0}.scale-note{font-size:8px}.field-bottom span:first-child{font-size:8px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}#ref-legend{font-size:8px}.legend{font-size:8px}#board{width:100%;height:100%;min-height:0;max-height:none;aspect-ratio:auto}
 .console{grid-row:5;min-height:0;margin:0;display:grid;grid-template-rows:60px 34px 188px 12px;gap:3px;position:relative}.controls{display:contents}.answer-heading{display:none}.answer-row{grid-row:1;height:60px;min-height:0;padding:3px 5px 3px 10px;gap:4px;border-radius:12px}.equals{font-size:22px}math-field{font-size:25px;max-height:54px;overflow-y:auto}.answer-row>#clear{min-width:36px;min-height:44px;padding:4px;font-size:10px}.primary{min-height:48px;min-width:80px;font-size:14px;padding-inline:10px}#next{font-size:12px;min-width:88px}
 .input-status{display:none;grid-row:2;margin:0;font-size:11px;line-height:1.4;max-height:34px;overflow:auto;align-self:center}.has-error .input-status{display:block}.has-error .action-row{display:none}.action-row{grid-row:2;margin:0;min-height:0;max-height:34px;overflow:auto}.action-row p{font-size:11px;line-height:1.45}
 #keypad{grid-row:3;height:188px;grid-template-columns:repeat(6,minmax(0,1fr));grid-template-rows:repeat(4,44px);gap:4px}#keypad button{height:44px;min-height:44px;font-size:18px;border-radius:9px}#keypad button.edit{font-size:17px}.console[data-mode=equation] #keypad{grid-template-columns:repeat(7,minmax(0,1fr));column-gap:3px}.console[data-mode=equation] #keypad button{font-size:17px}.console[data-mode=equation] #keypad button.edit{font-size:15px}
 .keyboard-note{grid-row:4;margin:0;line-height:12px;font-size:8px;white-space:nowrap}footer{display:none}
}
@media(max-width:350px){.shell{padding-inline:10px}.brand{font-size:15px}h1{font-size:18px}.mission>p{font-size:10px}.top .quiet{font-size:10px;padding-inline:5px}.primary{min-width:73px;font-size:12px}#next{min-width:84px;font-size:11px}.answer-row>#clear{min-width:30px;font-size:9px}.equals{font-size:20px}.keyboard-note{font-size:7px}}
@media(max-width:799px) and (max-height:520px){.shell{grid-template-rows:32px 3px auto minmax(65px,1fr) auto;gap:3px;padding-block:3px}.top .quiet{min-height:32px}.brand-icon{width:24px;height:24px}.eyebrow{display:none}.mission>p{font-size:10px}.console{grid-template-rows:54px 28px 188px;gap:2px}.answer-row{height:54px}.keyboard-note{display:none}.action-row,.input-status{max-height:28px}.action-row p,.input-status{font-size:10px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}
#ref-legend{color:var(--purple);font-weight:600}
#board text{font-size:var(--grid-font,10px)}#board .point-label,#board .cannon-label{font-size:var(--point-font,12px)}
.top-actions{display:flex;gap:5px}
.console[data-mode=equation] #keypad{grid-template-columns:repeat(7,minmax(0,1fr))}

.portal{position:fixed;inset:0;overflow:auto;padding:30px max(20px,calc((100vw - 600px)/2));padding-bottom:max(30px,env(safe-area-inset-bottom));background:var(--bg);z-index:3}.portal h1{font-size:28px;margin:12px 0}.portal h2{font-size:18px;margin:0 0 8px}.intro{color:var(--muted)}.portal-error{color:#b34822;min-height:20px}.login-form{display:grid;gap:10px;max-width:420px}.login-form label{font-weight:600}.login-form input{width:100%;border:1px solid #bdcfc2;border-radius:12px;padding:14px;font:inherit;font-size:18px;background:white;color:var(--ink)}.login-form button{margin-top:12px}.mode-cards{display:grid;gap:14px}.mode-cards button{text-align:left;min-height:70px;font-size:18px;padding:18px}.mode-cards button:first-child{background:#dceadf;color:#205d4c;box-shadow:none}.rules,.record{background:white;padding:20px;border:1px solid var(--line);border-radius:18px;margin-top:20px}.rules p,.record p{font-size:13px;line-height:1.65}.small{font-size:12px;color:var(--muted)}.portal-actions{display:flex;gap:12px;margin-top:16px}.record-summary{font-size:14px}.score{font-size:32px;display:block;color:var(--green);margin:12px 0}summary{cursor:pointer;padding:12px 0}.record details p{border-bottom:1px solid var(--line);padding-bottom:8px}.live-stats{grid-column:1/-1;font-size:10px;color:var(--green);font-variant-numeric:tabular-nums}.dialog-actions{flex-wrap:wrap}
/* Forest theme: warm paper, sage foliage and tactile controls. */
:root{--bg:#eef1e6;--ink:#3f5650;--muted:#74857b;--green:#578a77;--orange:#d17d45;--line:#d9dfcf}
body{background:radial-gradient(ellipse at 5% 95%,#c5d2b2 0,transparent 40%),radial-gradient(ellipse at 95% 10%,#fefcf2 0,transparent 50%),#edf0e7}
.shell{max-width:1080px}.top{background:#fffcf5dd;border-radius:32px;padding:8px 14px;box-shadow:0 5px 18px #596c4a08}.brand{color:#45635a}.brand-icon{color:#d8844d}.top .quiet{background:transparent}.field{border:0;background:#eef1e4aa;border-radius:22px;box-shadow:none}.field-top{font-size:11px}.field-top #zoom{font-size:11px;min-height:32px;padding:3px 5px;color:#547568}.field-bottom{background:#fffcf560}.scale-note{font-size:10px!important;white-space:nowrap}#ref-legend{color:#617c83;font-size:11px!important;line-height:1.3}#board text,#zoom-board text{font-family:inherit}#board .tick,#zoom-board .tick{fill:#64786c;font-size:11px}#board .axis-name,#zoom-board .axis-name{font-size:15px;font-style:italic;fill:#415d51}#board .point-label,#zoom-board .point-label{fill:#ba6435;font-size:12px;font-weight:650}#board .cannon-label,#zoom-board .cannon-label{fill:#426d5b;font-size:10px;font-weight:600}#board .scene-success{fill:#427c65;font-size:17px;font-weight:700}#board .question-mark{fill:#c07b47;font-size:24px;font-weight:bold}.primary{background:linear-gradient(120deg,#87b59b,#547e76);box-shadow:0 4px 8px #46644b19;border-radius:18px}.primary:hover{background:#5b8a77}.answer-row{border:2px solid #d4d9cb;border-radius:20px;background:#fffdf8;box-shadow:0 7px 18px #51623e06}#keypad button{border-radius:16px;background:#fffdf8;border:1px solid #e3e7d9;border-bottom:4px solid #d8dfce;font-size:24px}#keypad button.operator{background:#dfe9d9;color:#466f5e}#keypad button.edit{background:#dce7d9}.console{background:#fffcf566;border-radius:24px;padding:16px}.mission h1{font-weight:650;letter-spacing:2px}#progress span{background:#dfe5d7}#progress .current{background:#64937c}.portal{max-width:900px;padding:clamp(22px,5vw,60px);margin:24px auto;background:#fffcf2d9;border:1px solid #fff;border-radius:34px;box-shadow:0 18px 60px #566b4b0d}.portal h1{font-size:clamp(28px,5vw,42px);font-weight:650;letter-spacing:2px}.portal h2{font-size:19px}.portal .intro{font-size:15px;color:#6a7b6e}.portal .mode-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-block:22px}.mode-card{display:flex;flex-direction:column;align-items:flex-start;border-radius:22px;background:#f1f3e7;padding:20px}.mode-card p{font-size:14px;color:#6d7d70;flex:1}.mode-card h2{margin:0}.mode-card .primary{font-size:14px}.login-form{max-width:440px;margin:22px 0}.portal input,.portal select{background:#fffef9;border:1px solid #d1d9c9;border-radius:12px;min-height:48px;padding:10px;font-size:17px;color:var(--ink)}.portal .quiet{font-size:14px;min-height:44px;color:#4f7762;background:#e7eddf}.portal-actions{display:flex;gap:8px;flex-wrap:wrap;margin:24px 0}.difficulty-label{font-size:14px;display:block}.rules{padding:20px;background:#f1f3e9;border-radius:18px;margin-top:20px;font-size:14px}.rules summary{cursor:pointer;min-height:26px}.record{border:1px solid #dfe5d6;border-radius:20px;padding:20px;margin:15px 0;background:#fffdf6}.score{font-size:34px;color:#54856e}.small{font-size:12px;color:#7c887d}.ranking-row{padding:12px;background:#f0f3e6;border-radius:12px}.portal-error{color:#aa6541}.live-stats{font-size:11px;color:#5e7868;font-variant-numeric:tabular-nums}.misfire .cannon{animation:wiggle .35s ease-in-out}.burst{transform-origin:center;animation:burst .35s ease-out}#zoom-dialog{max-width:min(96vw,800px);width:96vw;max-height:94dvh;padding:12px}#zoom-board svg{width:100%;max-height:72dvh}#zoom-dialog p{font-size:12px;margin:5px}#zoom-dialog .primary{min-height:44px;margin:0}#zoom-board .point-label{font-size:12px}
@keyframes wiggle{0%,100%{opacity:1}30%,70%{opacity:.35}}@keyframes burst{from{opacity:.1}to{opacity:.7}}
@media(prefers-reduced-motion:reduce){.misfire .cannon,.burst{animation:none}}
@media(max-width:799px){
 .portal{max-height:var(--play-height,100dvh);height:auto;margin:0;border-radius:0;overflow:auto;padding:26px 20px;padding-bottom:40px}.portal .mode-cards{grid-template-columns:1fr;gap:10px}.mode-card{display:grid;grid-template-columns:1fr auto;gap:6px 10px;padding:15px}.mode-card h2{font-size:17px}.mode-card p{grid-column:1;margin:0;font-size:12px}.mode-card button{grid-column:2;grid-row:1/3;align-self:center}.portal h1{font-size:30px}.portal .intro{font-size:13px}
 .shell{max-width:520px;padding:6px 9px max(6px,env(safe-area-inset-bottom));gap:4px;grid-template-rows:44px 4px auto minmax(90px,1fr) auto}.top{padding:0 10px}.mission{column-gap:8px}.mission h1{font-size:18px}.mission>p{font-size:11px}.field{grid-template-rows:26px minmax(0,1fr) 16px}.field-top{padding:0 5px;gap:4px}.field-top #zoom{min-height:26px;padding:2px;font-size:10px}.field-bottom{padding:0 9px}.console{padding:6px;background:#fffcf5bb;border-radius:20px;grid-template-rows:54px 30px 188px;gap:4px}.answer-row{height:54px;border-radius:15px}.primary{border-radius:13px;min-height:44px}.keyboard-note{display:none}.action-row,.input-status{max-height:30px}#keypad button{border-radius:12px;font-size:22px}.live-stats{grid-column:1/-1;font-size:10px;line-height:14px}.eyebrow{font-size:9px}.field #ref-legend{font-size:9px!important}.shell footer{display:none}
}
@media(max-width:360px){.console{grid-template-rows:50px 28px 188px}.answer-row{height:50px}.mission>p{font-size:10px}.shell{gap:3px}.field #ref-legend{font-size:8px!important}}
/* In short landscape viewports, keys flank an undistorted central graph. */


#console[data-mode="equation"] #keypad{grid-template-columns:repeat(6,minmax(0,1fr))}

.reference-equation{grid-column:1/-1;font-size:16px!important;color:#4f737c!important;background:#e1eae7;border:1px solid #cedbd6;border-radius:9px;padding:7px 12px;margin:6px 0;font-weight:650;line-height:1.4} @media(max-width:799px){.reference-equation{font-size:13px!important;margin:2px 0;padding:4px 8px}}

#board .point-label{font-size:var(--point-font,12px)}#board .cannon-label{font-size:var(--cannon-font,10px)}#board .tick{font-size:var(--tick-font,11px)}.mode-card .primary{min-height:48px;padding:10px 14px;text-align:center}.portal{height:fit-content;max-height:calc(var(--play-height,100dvh) - 48px)}@media(max-width:799px){.portal{max-height:var(--play-height,100dvh);height:100%}}

#board .apple-label,#zoom-board .apple-label{font-size:11px;fill:#a25f3e;font-weight:700}
/* Long MathLive input must scroll inside its field, never widen the play grid. */
.answer-row{min-width:0;max-width:100%}.answer-row>math-field{width:0;flex:1 1 0%;overflow-x:auto}.console{grid-template-columns:minmax(0,1fr)}
@media(max-width:799px) and (orientation:portrait){.shell{grid-template-columns:minmax(0,1fr)}}

/* Two columns at each thumb, six rows; the middle stays available for the graph. */

.mode-card .examples{font-size:12px;min-height:36px;padding:5px 10px;box-shadow:none}
@media(max-width:799px){.mode-card .examples{grid-column:1;grid-row:auto;justify-self:start}}
#zoom-dialog[open]{display:flex;flex-direction:column;width:min(98vw,1000px);height:96dvh;max-height:96dvh;padding:10px;gap:4px}
.zoom-toolbar{display:flex;gap:6px;align-items:center}.zoom-toolbar button{min-height:44px;min-width:44px;padding:6px 10px}.zoom-toolbar #close-zoom{margin:0 0 0 auto}
#zoom-board{flex:1;min-height:0;overflow:hidden}#zoom-board svg{width:100%;height:100%;max-height:none;touch-action:none;user-select:none;cursor:grab}#zoom-board svg:active{cursor:grabbing}
#zoom-dialog p{margin:0;font-size:12px}#zoom-dialog #zoom-condition{color:#496b65;font-size:13px}#zoom-range{font-variant-numeric:tabular-nums}
#zoom-canvas .point-label{font-size:var(--point-font,12px)}#zoom-canvas .cannon-label{font-size:var(--cannon-font,10px)}#zoom-canvas .tick{font-size:var(--tick-font,11px)}