:root{
  color-scheme:light dark;
  --bg:#eef1f4;--panel:#f8fafb;--key:#fff;--key2:#e4e8ec;--text:#15191d;--muted:#6b747d;
  --line:#cfd5db;--accent:#ccff00;--accentText:#111;--op:#222930;--opText:#fff;
  --shadow:0 24px 70px rgba(20,25,30,.18);--inset:inset 0 1px 0 rgba(255,255,255,.6)
}
@media(prefers-color-scheme:dark){
  html[data-theme="auto"]{--bg:#090b0d;--panel:#11151a;--key:#1b2127;--key2:#252c33;--text:#f4f7f8;--muted:#89949e;--line:#2b333b;--op:#303942;--opText:#fff;--shadow:0 30px 90px rgba(0,0,0,.55);--inset:inset 0 1px 0 rgba(255,255,255,.05)}
}
html[data-theme="dark"]{--bg:#090b0d;--panel:#11151a;--key:#1b2127;--key2:#252c33;--text:#f4f7f8;--muted:#89949e;--line:#2b333b;--op:#303942;--opText:#fff;--shadow:0 30px 90px rgba(0,0,0,.55);--inset:inset 0 1px 0 rgba(255,255,255,.05)}
html[data-theme="light"]{--bg:#eef1f4;--panel:#f8fafb;--key:#fff;--key2:#e4e8ec;--text:#15191d;--muted:#6b747d;--line:#cfd5db;--op:#222930;--opText:#fff}
*{box-sizing:border-box}
body{margin:0;min-height:100vh;background:radial-gradient(circle at 50% 0%,color-mix(in srgb,var(--accent) 7%,var(--bg)),var(--bg) 35%);font-family:Inter,ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:var(--text)}
button,input,select{font:inherit;color:inherit}
.shell{width:min(96vw,1100px);margin:0 auto;padding:22px}
.brandbar{display:flex;align-items:center;justify-content:space-between;margin-bottom:8px}
.brand{display:flex;gap:10px;align-items:center;text-decoration:none;color:var(--text);letter-spacing:.08em}
.brand .mark{display:grid;place-items:center;width:38px;height:38px;border:1px solid var(--line);border-radius:10px;font-weight:900;background:var(--panel)}
.brand strong,.brand small{display:block}.brand strong{font-size:13px}.brand small{font-size:9px;color:var(--muted);letter-spacing:.22em}
.toolbar{display:flex;gap:8px}.iconbtn{width:38px;height:38px;border-radius:10px;border:1px solid var(--line);background:var(--panel);cursor:pointer}
.workspace-note{color:var(--muted);font-size:11px;margin:10px 2px 14px}
.workspace{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;align-items:start}
.tool-panel{min-width:0;background:var(--panel);border:1px solid var(--line);border-radius:24px;box-shadow:var(--shadow),var(--inset);overflow:hidden}
.tool-panel.dragging{opacity:.5}.tool-panel.drop-before{outline:2px solid var(--accent);outline-offset:3px}
.panel-head{height:48px;display:flex;align-items:center;justify-content:space-between;padding:0 12px 0 15px;border-bottom:1px solid var(--line);cursor:grab;user-select:none}
.panel-head:active{cursor:grabbing}.panel-head>div{display:flex;align-items:center;gap:8px;letter-spacing:.1em;font-size:11px}.dragmark{color:var(--muted);font-size:18px}
.collapse-btn{width:34px;height:34px;border:0;border-radius:9px;background:transparent;color:var(--muted);cursor:pointer;font-size:20px}.collapse-btn:hover{background:var(--key2);color:var(--text)}
.tool-panel.collapsed .panel-body{display:none}.tool-panel.collapsed .panel-head{border-bottom:0}
.panel-body{padding:16px}
.calculator{background:transparent}.display{min-height:145px;padding:20px 10px 18px;display:flex;flex-direction:column;align-items:flex-end;justify-content:flex-end;overflow:hidden}
.history{width:100%;text-align:right;min-height:22px;color:var(--muted);font-size:15px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.value{width:100%;padding-right:8px;text-align:right;font-variant-numeric:tabular-nums;font-size:clamp(42px,7vw,66px);font-weight:650;line-height:1.05;letter-spacing:-.055em;white-space:nowrap;overflow:hidden}
.memory-strip{display:grid;grid-template-columns:repeat(4,1fr) 26px;gap:6px;align-items:center;margin:0 2px 10px}
.memory-strip button{border:0;background:transparent;color:var(--muted);height:30px;border-radius:8px;cursor:pointer;font-size:12px;font-weight:700}
.memory-strip button:hover{background:var(--key2);color:var(--text)}.memory-lamp{font-size:11px;font-weight:900;color:var(--muted);opacity:.25;text-align:center}.memory-lamp.on{color:var(--accent);opacity:1}
.keys{display:grid;grid-template-columns:repeat(4,1fr);gap:9px}.keys button,.quick button{border:1px solid var(--line);background:var(--key);border-radius:16px;min-height:68px;cursor:pointer;font-size:23px;font-weight:650;box-shadow:var(--inset);transition:transform .06s ease,filter .1s ease}
.keys button:active,.quick button:active,.pressed{transform:scale(.96);filter:brightness(.9)}.keys .utility{background:var(--key2);font-size:18px}.keys .operator{background:var(--op);color:var(--opText)}.keys .equals{background:var(--accent);color:var(--accentText);border-color:color-mix(in srgb,var(--accent) 65%,#000);font-weight:900}.keys .wide{grid-column:span 2;text-align:left;padding-left:29px}
.quick{display:grid;grid-template-columns:repeat(4,1fr);gap:7px;margin-top:10px}.quick button{min-height:42px;border-radius:12px;font-size:13px;color:var(--muted)}
.converter{padding:22px}.field-label{display:block;color:var(--muted);font-size:11px;font-weight:800;letter-spacing:.08em;margin:0 0 7px}
.converter select,.converter input,.convert-output{width:100%;border:1px solid var(--line);background:var(--key);border-radius:14px;min-height:48px;padding:0 13px}
.converter input{font-size:24px;font-weight:700;margin-bottom:8px}.converter>select{margin-bottom:22px}
.convert-grid{display:grid;grid-template-columns:minmax(0,1fr) 44px minmax(0,1fr);gap:10px;align-items:end}.swap-btn{width:44px;height:48px;border:1px solid var(--line);background:var(--key2);border-radius:13px;cursor:pointer;margin-bottom:0}
.convert-output{display:flex;align-items:center;font-size:24px;font-weight:700;margin-bottom:8px;overflow:hidden;white-space:nowrap}.formula{min-height:20px;margin-top:16px;color:var(--muted);font-size:12px;line-height:1.5}
footer{display:flex;justify-content:space-between;gap:12px;padding:14px 5px 0;color:var(--muted);font-size:11px;letter-spacing:.04em}.kbd{text-align:right}
@media(max-width:780px){.workspace{grid-template-columns:1fr}.shell{width:min(96vw,540px)}}
@media(max-width:390px){.shell{padding:10px}.tool-panel{border-radius:22px}.keys button{min-height:60px}.display{min-height:126px}.brandbar{padding:0 3px}.convert-grid{grid-template-columns:1fr}.swap-btn{width:100%;height:40px}.kbd{display:none}}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}
/* v0.2 workspace: independent floating tool panels */
body{display:block;place-items:unset;min-height:100vh}
.shell{width:100%;max-width:none;padding:22px 28px;margin:0}
.workspace-note{margin:10px 2px 14px}
.workspace{position:relative;display:block;min-height:760px;width:100%;overflow:hidden}
.tool-panel{position:absolute;min-width:300px;max-width:min(94vw,480px);background:var(--panel);border:1px solid var(--line);border-radius:24px;box-shadow:var(--shadow),var(--inset);overflow:hidden}
.tool-panel[data-tool="calculator"]{left:0;top:0;width:440px}
.tool-panel[data-tool="converter"]{left:464px;top:0;width:420px}
.panel-head{cursor:grab}.panel-head:active{cursor:grabbing}
.tool-panel.dragging{opacity:.92;box-shadow:0 32px 100px rgba(0,0,0,.35)}
.tool-panel.drop-before{outline:0}
@media(max-width:920px){.workspace{min-height:1200px}.tool-panel[data-tool="converter"]{left:0;top:650px}.tool-panel{max-width:100%}}

/* v0.3: full-page canvas + full-width WereByte header */
.shell{width:100%;max-width:none;margin:0;padding:0}
.brandbar{height:72px;margin:0;padding:16px 28px;border-bottom:1px solid var(--line);background:color-mix(in srgb,var(--panel) 82%,transparent)}
.workspace-note{display:none}
.workspace{position:relative;display:block;width:100%;min-height:calc(100vh - 112px);overflow:visible;padding:0}
.tool-panel[data-tool="calculator"]{left:28px;top:28px}
.tool-panel[data-tool="converter"]{left:492px;top:28px}
footer{padding:12px 28px 18px}
@media(max-width:920px){.workspace{min-height:calc(100vh - 112px)}.tool-panel[data-tool="calculator"]{left:14px;top:18px}.tool-panel[data-tool="converter"]{left:14px;top:670px}}

/* v0.4 header tagline + compact bottom footer */
body{min-height:100vh;display:flex;flex-direction:column}
.shell{min-height:100vh;display:flex;flex-direction:column}
.brand{min-width:0}
.tagline{margin-left:8px;color:var(--muted);font-size:11px;letter-spacing:.04em;white-space:nowrap}
.workspace{flex:1;min-height:calc(100vh - 104px)}
footer{margin-top:auto;min-height:32px;padding:8px 28px;border-top:1px solid var(--line);display:flex;align-items:center;justify-content:center;color:var(--muted);font-size:10px;letter-spacing:.04em}
@media(max-width:520px){.tagline{display:none}footer{padding:8px 14px}}

/* v0.5: true 32px document footer; workspace grows around floating panels */
.shell{min-height:100vh;height:auto}
.workspace{flex:1 0 auto;min-height:calc(100vh - 104px);overflow:visible}
footer{height:32px;min-height:32px;max-height:32px;flex:0 0 32px;margin-top:0;padding:0 28px;line-height:32px;overflow:hidden}
@media(max-width:520px){footer{height:32px;min-height:32px;max-height:32px;padding:0 14px;line-height:32px}}


/* v0.8: keep native selects, but give the browser an explicitly opaque palette. */
html[data-theme="dark"]{color-scheme:dark}
html[data-theme="light"]{color-scheme:light}
@media(prefers-color-scheme:dark){html[data-theme="auto"]{color-scheme:dark}}
@media(prefers-color-scheme:light){html[data-theme="auto"]{color-scheme:light}}

html[data-theme="dark"] .converter select,
html[data-theme="dark"] .converter select option{
  background-color:#1b2127;
  color:#f4f7f8;
  color-scheme:dark;
}
html[data-theme="light"] .converter select,
html[data-theme="light"] .converter select option{
  background-color:#ffffff;
  color:#15191d;
  color-scheme:light;
}
@media(prefers-color-scheme:dark){
  html[data-theme="auto"] .converter select,
  html[data-theme="auto"] .converter select option{
    background-color:#1b2127;
    color:#f4f7f8;
    color-scheme:dark;
  }
}
@media(prefers-color-scheme:light){
  html[data-theme="auto"] .converter select,
  html[data-theme="auto"] .converter select option{
    background-color:#ffffff;
    color:#15191d;
    color-scheme:light;
  }
}


/* v1.0 custom dropdowns: web-rendered popup is portaled to <body>, so panel overflow cannot clip it. */
.native-select{position:absolute!important;width:1px!important;height:1px!important;opacity:0!important;pointer-events:none!important;clip-path:inset(50%)!important}
.custom-select{position:relative;width:100%;min-height:48px;padding:0 40px 0 13px;border:1px solid var(--line);border-radius:14px;background:var(--key);color:var(--text);font:inherit;text-align:left;cursor:pointer;box-shadow:var(--inset)}
.custom-select::after{content:"";position:absolute;right:15px;top:50%;width:7px;height:7px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:translateY(-70%) rotate(45deg);opacity:.8}
.custom-select:hover{background:var(--key2)}
.custom-select:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.converter>.custom-select{margin-bottom:22px}
.custom-select-menu{position:fixed;z-index:100000;max-height:min(300px,calc(100vh - 16px));overflow:auto;padding:6px;border:1px solid var(--line);border-radius:14px;background:var(--panel);color:var(--text);box-shadow:0 18px 55px rgba(0,0,0,.45);overscroll-behavior:contain}
.custom-select-option{display:block;width:100%;min-height:38px;padding:8px 10px;border:0;border-radius:9px;background:transparent;color:inherit;font:inherit;text-align:left;cursor:pointer;white-space:nowrap}
.custom-select-option:hover,.custom-select-option.active{background:var(--key2)}
.custom-select-option[aria-selected="true"]{font-weight:750;color:var(--text)}
.custom-select-option[aria-selected="true"]::before{content:"✓";display:inline-block;width:20px;color:var(--accent)}
.custom-select-option[aria-selected="false"]::before{content:"";display:inline-block;width:20px}

/* v1.1 date calculator */
.tool-panel[data-tool="date"]{left:936px;top:28px;width:420px}
.datecalc{padding:22px}
.date-tabs{display:grid;grid-template-columns:repeat(3,1fr);gap:6px;margin-bottom:18px;padding:5px;border:1px solid var(--line);border-radius:14px;background:var(--key)}
.date-tab{min-height:36px;border:0;border-radius:10px;background:transparent;color:var(--muted);font:inherit;font-size:12px;font-weight:800;cursor:pointer}
.date-tab:hover{background:var(--key2);color:var(--text)}
.date-tab.active{background:var(--panel);color:var(--text);box-shadow:0 2px 8px rgba(0,0,0,.18)}
.date-mode{display:none}.date-mode.active{display:block}
.date-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.datecalc input,.datecalc select{width:100%;min-height:48px;padding:0 13px;border:1px solid var(--line);border-radius:14px;background:var(--key);color:var(--text);font:inherit}
.datecalc input[type="number"]{font-size:18px;font-weight:700}
.datecalc input[type="date"]{font-size:15px;font-weight:700;color-scheme:dark}
html[data-theme="light"] .datecalc input[type="date"]{color-scheme:light}
@media(prefers-color-scheme:light){html[data-theme="auto"] .datecalc input[type="date"]{color-scheme:light}}
.date-result{margin-top:16px;padding:16px;border:1px solid var(--line);border-radius:16px;background:var(--display);box-shadow:var(--inset)}
.date-result-main{font-size:25px;font-weight:850;letter-spacing:-.02em;line-height:1.2}
.date-result-sub{margin-top:7px;color:var(--muted);font-size:12px;line-height:1.5}
.date-direction{display:grid;grid-template-columns:1fr 1fr;gap:6px;margin:0 0 12px}
.date-direction button{min-height:38px;border:1px solid var(--line);border-radius:11px;background:var(--key);color:var(--muted);font:inherit;font-size:12px;font-weight:800;cursor:pointer}
.date-direction button.active{background:var(--accent);border-color:var(--accent);color:#fff}
@media(max-width:1380px) and (min-width:921px){.tool-panel[data-tool="date"]{left:492px;top:480px}}
@media(max-width:920px){.tool-panel[data-tool="date"]{left:14px;top:1120px}}

/* Percentage Calculator — v1.8 */

.percent-body{display:flex;flex-direction:column;gap:14px}
.percent-modes{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:7px}
.percent-mode{min-height:36px;border:1px solid var(--line,#343a40);border-radius:9px;background:var(--key,#20252b);color:inherit;font:inherit;font-size:12px;cursor:pointer;padding:7px 8px}
.percent-mode.active{border-color:var(--accent,#50c8ff);box-shadow:inset 0 0 0 1px var(--accent,#50c8ff)}
.percent-fields{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.percent-field{display:flex;flex-direction:column;gap:6px;min-width:0;font-size:12px;color:var(--muted,#9ca6af)}
.percent-field input,.percent-field select{width:100%;box-sizing:border-box;min-height:42px;border:1px solid var(--line,#343a40);border-radius:9px;background:var(--input,#15191e);color:inherit;padding:8px 10px;font:inherit;font-size:16px;outline:none}
.percent-field input:focus,.percent-field select:focus{border-color:var(--accent,#50c8ff)}
.percent-result-wrap{border-top:1px solid var(--line,#343a40);padding-top:12px}
.percent-result-label{font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted,#9ca6af)}
.percent-result{display:block;font-size:28px;font-weight:700;line-height:1.25;margin-top:3px;overflow-wrap:anywhere}
.percent-explain{font-size:12px;color:var(--muted,#9ca6af);margin-top:4px;overflow-wrap:anywhere}
@media(max-width:520px){.percent-fields{grid-template-columns:1fr}}




/* v2.4 — percentage is a standard floating panel; generic panel JS owns drag/save/reset */
/* Same 24px gutter as calculator→converter and converter→date.
   Converter is 346px tall at top:28, so 28 + 346 + 24 = 398. */
.tool-panel[data-tool="percentage"]{left:492px;top:398px;width:420px}
@media(max-width:1380px) and (min-width:921px){.tool-panel[data-tool="percentage"]{left:28px;top:747px}}
@media(max-width:920px){.tool-panel[data-tool="percentage"]{left:14px;top:1478px}}