@font-face{font-family:Calculator;src:url('google-sans-light.ttf') format('truetype');font-weight:300 400;font-display:swap}
:root{color-scheme:dark;--bg:#121212;--key:#343434;--op:#484848;--accent:#dedede;--ink:#dedede;--accent-ink:#080808;--panel:#343434;--muted:#bcbcbc;--line:#555;--focus:#c3c3c3}
:root[data-theme=light]{color-scheme:light;--bg:#f5f5f5;--key:#e5e5e5;--op:#d1d1d1;--accent:#333;--ink:#171717;--accent-ink:#fff;--panel:#eee;--muted:#555;--line:#bbb;--focus:#444}
*{box-sizing:border-box}html,body{margin:0;width:100%;height:100%;min-height:0;overflow:hidden;overscroll-behavior:none;background:var(--bg);color:var(--ink)}body{position:fixed;inset:0;height:var(--app-height,100%);font-family:Calculator,Arial,sans-serif;font-weight:300;-webkit-tap-highlight-color:transparent}button,input,select{font:inherit}button{cursor:pointer;border:0;color:inherit;background:none;touch-action:manipulation}button:focus-visible,[tabindex]:focus-visible{outline:2px solid var(--focus);outline-offset:-4px}button:active{filter:brightness(1.24)}svg{fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round;width:24px;height:24px;flex-shrink:0}.svg-defs{display:none}[hidden]{display:none!important}
.calculator{
 --safe-top:env(safe-area-inset-top,0px);--safe-bottom:env(safe-area-inset-bottom,0px);
 --safe-side:max(env(safe-area-inset-left,0px),env(safe-area-inset-right,0px));
 --screen-height:var(--app-height,100vh);--max-width:576px;--header-height:64px;--min-display:112px;
 --top-pad:calc(var(--safe-top) + 8px);--bottom-pad:calc(var(--safe-bottom) + 8px);
 /* Five rows of circular keys, four gaps, and equal side margins occupy 1.22725 × width. */
 --w:min(calc(100vw - var(--safe-side) - var(--safe-side)),var(--max-width),calc((var(--screen-height) - var(--top-pad) - var(--bottom-pad) - var(--header-height) - var(--min-display)) / 1.22725));
 width:var(--w);height:var(--screen-height);margin:0 auto;display:flex;flex-direction:column;position:relative;
 padding:var(--top-pad) 0 var(--bottom-pad);overflow:hidden;overscroll-behavior:none;touch-action:pinch-zoom;
}
@supports(height:100svh){.calculator{--screen-height:var(--app-height,100svh)}}
@supports(height:100dvh){.calculator{--screen-height:var(--app-height,100dvh)}}
.toolbar{position:relative;z-index:2;flex:0 0 var(--header-height);height:var(--header-height);min-height:var(--header-height);display:flex;justify-content:space-between;align-items:center;padding:0 calc(var(--w)*.022)}.icon-button{width:48px;height:48px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;color:var(--muted);flex-shrink:0}.toolbar .icon-button svg{width:23px;height:23px}.dots{fill:currentColor;stroke:none}.display-area{flex:1;min-height:var(--min-display);position:relative;display:flex;flex-direction:column}.display{width:100%;padding:8px calc(var(--w)*.047) 0 calc(var(--w)*.04);height:calc(var(--w)*.29);min-height:78px;text-align:right;user-select:none;-webkit-user-select:none;touch-action:pinch-zoom;overflow:hidden;font-size:calc(var(--w)*.174);line-height:1.35;font-weight:300;white-space:nowrap;letter-spacing:0}.display #display-content{display:inline-flex;align-items:center;max-width:100%;min-height:1.35em}.caret{display:inline-block;width:1.5px;height:1.28em;margin-left:3px;background:var(--ink);animation:blink 1.1s steps(1) infinite;flex-shrink:0}.result .caret{display:none}.expand{position:absolute;bottom:17px;left:10px}.expand svg{width:20px;height:20px;stroke-width:2.3}.keypad{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:calc(var(--w)*.009);padding:0 calc(var(--w)*.01);flex-shrink:0}.key{border-radius:50%;aspect-ratio:1;min-width:0;display:flex;align-items:center;justify-content:center;background:var(--key);font-size:calc(var(--w)*.103);font-weight:300;padding:0;user-select:none;-webkit-user-select:none;line-height:1;transition:background .12s,transform .1s}.key.operator{background:var(--op);font-size:calc(var(--w)*.113)}.key.accent{background:var(--accent);color:var(--accent-ink);font-weight:400}.key[data-key="AC"]{font-size:calc(var(--w)*.10)}.key[data-key="="]{font-size:calc(var(--w)*.12)}.key[data-key="backspace"] svg{width:calc(var(--w)*.095);height:calc(var(--w)*.095);stroke-width:2.6}.key:active{transform:scale(.96)}.menu-backdrop{position:fixed;inset:0;z-index:4}.menu{position:absolute;z-index:5;top:calc(var(--top-pad) + var(--header-height));right:calc(var(--w)*.029);width:76%;border-radius:28px;background:var(--panel);padding:10px 0;box-shadow:0 4px 14px #0001}.menu button{width:100%;height:calc(var(--w)*.117);min-height:44px;text-align:left;padding:0 calc(var(--w)*.043);display:flex;align-items:center;gap:calc(var(--w)*.045);font-size:calc(var(--w)*.04);white-space:nowrap}.menu button svg{width:calc(var(--w)*.045);height:calc(var(--w)*.045);color:var(--muted)}.menu button:hover{background:#8882}
dialog{overflow-y:auto;overscroll-behavior:contain;touch-action:pan-y pinch-zoom;-webkit-overflow-scrolling:touch;position:fixed;margin:auto;border:1px solid var(--line);border-radius:28px;background:var(--panel);color:var(--ink);width:min(92vw,440px);max-height:calc(var(--app-height,100dvh) - env(safe-area-inset-top,0px) - env(safe-area-inset-bottom,0px) - 24px);padding:20px;box-shadow:0 16px 70px #0005;font-family:Calculator,Arial,sans-serif;font-size:16px;line-height:1.5}dialog::backdrop{background:#0008;backdrop-filter:blur(3px)}.panel-header{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:10px}.panel-header h1{font-size:24px;line-height:1.2;font-weight:400;margin:0}.panel-header button{font:32px Arial;width:36px;height:36px}p{margin:10px 0 16px}.muted,small{color:var(--muted)}fieldset{border:0;padding:0;margin:16px 0}legend,h2{font-size:18px;font-weight:400;margin-bottom:8px}.option{display:flex;align-items:flex-start;gap:12px;padding:12px 0;cursor:pointer}.option input{accent-color:var(--ink);width:20px;height:20px;margin-top:3px;flex-shrink:0}.option small{display:block;font-size:13px;margin-top:3px}.action{display:inline-flex;justify-content:center;align-items:center;min-height:44px;border-radius:22px;padding:9px 18px;background:var(--accent);color:var(--accent-ink);font-weight:400;margin:8px 4px 4px 0}.secondary{background:var(--key);color:var(--ink);border:1px solid var(--line)}.field{display:flex;flex-direction:column;gap:6px;margin:12px 0}.field input,.field select{min-height:44px;background:var(--bg);color:var(--ink);border:1px solid var(--line);border-radius:10px;padding:8px;max-width:100%;width:100%}details{border-top:1px solid var(--line);padding-top:14px;margin-top:14px}summary{cursor:pointer;min-height:32px}#sensor-status{font-size:13px;color:var(--muted)}.history-row{border-bottom:1px solid var(--line);padding:14px 0;text-align:right;overflow-wrap:anywhere}.history-row strong{display:block;font-weight:400;font-size:25px}.test-output{overflow-wrap:anywhere}.test-output strong{font-size:26px;display:block}#toast{position:fixed;bottom:28px;left:50%;transform:translateX(-50%);padding:12px 20px;border-radius:24px;background:var(--ink);color:var(--bg);z-index:20;max-width:90vw;font-size:15px;text-align:center}@keyframes blink{0%,48%{opacity:1}49%,100%{opacity:0}}@media(prefers-reduced-motion:reduce){.caret{animation:none}.key{transition:none}}
@media(min-width:650px){.calculator{--max-width:440px;border-inline:1px solid #7772}}
@media(max-height:700px){.calculator{--header-height:56px;--min-display:100px}.expand{bottom:6px}}
@media(orientation:landscape) and (max-height:600px){
 .calculator{--w:min(calc(100vw - var(--safe-side) - var(--safe-side)),720px);--header-height:48px;display:grid;grid-template-columns:minmax(0,1fr) auto;grid-template-rows:var(--header-height) minmax(0,1fr);column-gap:16px;padding-inline:8px}
 .toolbar{grid-column:1;grid-row:1;padding:0}
 .display-area{grid-column:1;grid-row:2;min-height:0}
 .display{font-size:clamp(32px,7vw,52px);padding:10px 8px;min-height:72px;height:auto}
 .expand{left:0;bottom:4px}
 .keypad{--key-size:min(calc((var(--screen-height) - var(--top-pad) - var(--bottom-pad) - 16px) / 5),calc(var(--w)*.14));grid-column:2;grid-row:1/3;grid-template-columns:repeat(4,var(--key-size));grid-template-rows:repeat(5,var(--key-size));gap:4px;padding:0;align-self:center}
 .key{width:var(--key-size);height:var(--key-size);font-size:calc(var(--key-size)*.43)!important}
 .key[data-key="backspace"] svg{width:calc(var(--key-size)*.40);height:calc(var(--key-size)*.40)}
 .menu{top:calc(var(--top-pad) + var(--header-height));width:min(310px,calc(100% - 16px));right:8px}
 .menu button{height:46px;font-size:16px;gap:16px;padding:0 16px}.menu button svg{width:20px;height:20px}
}

/* Public help: four equal regions, with settings behind an unobtrusive version label. */
.help-intro{margin-bottom:18px}.help-map{position:relative;aspect-ratio:1;isolation:isolate;border:1px solid var(--line);border-radius:18px;overflow:hidden;background:var(--bg)}
.help-zone{position:absolute;inset:0;width:100%;height:100%;padding:0;border-radius:0;text-align:center;touch-action:manipulation;-webkit-user-select:none;user-select:none}
.help-zone span{position:absolute;transform:translate(-50%,-50%);width:48%;pointer-events:none;line-height:1.35}
.help-zone b{display:block;font-size:16px;font-weight:400}.help-zone small{display:block;font-size:12px;margin-top:3px}
.help-up{clip-path:polygon(0 0,100% 0,50% 50%)}.help-up span{left:50%;top:20%}
.help-down{clip-path:polygon(0 100%,50% 50%,100% 100%)}.help-down span{left:50%;top:80%}
.help-left{clip-path:polygon(0 0,50% 50%,0 100%)}.help-left span{left:20%;top:50%;width:38%}
.help-right{clip-path:polygon(100% 0,100% 100%,50% 50%)}.help-right span{left:80%;top:50%;width:38%}
.help-zone:active{background:#8881;filter:none}.help-zone:focus-visible{outline:0;background:#8882}
.help-dividers{position:absolute;inset:0;width:100%;height:100%;pointer-events:none;stroke:var(--line);stroke-width:.3;stroke-linecap:butt}
.help-note{font-size:14px;line-height:1.5;margin-top:16px;margin-bottom:4px}.help-footer{display:flex;justify-content:center;margin-top:4px}.help-version{min-height:44px;padding:8px 18px;color:var(--muted);font-size:12px;opacity:.65;border-radius:12px}
@media(max-width:350px){.help-zone b{font-size:14px}.help-zone small{font-size:11px}}