@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Manrope:wght@400;500;600;700;800&display=swap');
:root{--bg:#f4f4ef;--paper:#fff;--text:#203732;--muted:#75817a;--line:#e3e7df;--key:#f1f3ee;--accent:#cbe89d;--screen:#edf2e6;--soft:#f8f9f5;--danger:#a74738}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:'DM Sans',Arial,sans-serif;font-size:14px}body.dark{--bg:#14201e;--paper:#1d2d29;--text:#e6eee4;--muted:#a3b0a6;--line:#35443b;--key:#2b3a33;--screen:#263b2e;--soft:#23322c}button,input,textarea,select{font:inherit}button{cursor:pointer;color:inherit;border:1px solid var(--line);background:var(--paper);border-radius:8px;padding:8px 12px}button:hover{filter:brightness(.96);border-color:#93a482}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #74a950;outline-offset:3px}header{height:90px;border-bottom:1px solid var(--line);padding:0 5%;display:flex;align-items:center;justify-content:space-between;background:var(--paper)}.brand{font-family:Manrope,Arial,sans-serif;font-size:28px;font-weight:800;display:flex;align-items:center;gap:12px;color:var(--text);text-decoration:none;letter-spacing:-1px}.mark{background:#203d32;color:#e0efc9;border-radius:11px;width:38px;height:38px;text-align:center;font-family:Georgia;font-size:32px;position:relative}.mark span{font-size:18px;position:absolute;right:5px;top:-5px}.brand-sub{font-size:9px;letter-spacing:1.6px;font-weight:600;border-left:1px solid var(--line);margin-left:13px;padding-left:22px;color:var(--muted)}.header-right{display:flex;align-items:center;gap:12px;font-size:12px;color:var(--muted)}.local-dot{background:#7fa45e;width:6px;height:6px;border-radius:50%}.header-right button{color:var(--text)}main{max-width:1270px;margin:auto;padding:40px 40px 24px}.intro{display:flex;justify-content:space-between;align-items:center;margin-bottom:31px}.eyebrow{font-size:10px;letter-spacing:2px;color:#69815e;font-weight:700;margin:0 0 12px}h1{font-family:Manrope,Arial,sans-serif;letter-spacing:-1.6px;font-size:43px;margin:0 0 9px;font-weight:600}.intro p:not(.eyebrow){color:var(--muted);margin:0;font-size:14px}.version{font-size:9px;letter-spacing:1.5px;color:var(--muted);display:flex;gap:14px;align-items:center}.version b{border:1px solid var(--line);padding:10px;font-size:12px}.workspace{display:grid;grid-template-columns:minmax(0,1.62fr) minmax(300px,1fr);gap:25px;align-items:start}.calculator{background:var(--paper);border:1px solid var(--line);border-radius:18px;padding:21px;box-shadow:0 9px 28px #1b352007}.calc-heading{display:flex;justify-content:space-between;align-items:center;font-size:10px;font-weight:700;letter-spacing:1.6px;margin-bottom:17px}.calc-heading>div{display:flex;gap:8px}.calc-heading button,.calc-heading select{font-size:11px;letter-spacing:.4px;padding:6px 10px;background:var(--key);border:0;border-radius:6px;color:var(--text)}.screen{background:var(--screen);border:1px solid #8da37a33;border-radius:10px;padding:16px 18px 12px;min-height:186px}.screen-top{display:flex;justify-content:space-between;color:var(--muted);font-size:9px;letter-spacing:1.2px}textarea{width:100%;resize:vertical;min-height:54px;max-height:160px;background:transparent;border:0;color:var(--text);font-family:Consolas,monospace;font-size:22px;text-align:right;margin-top:15px;outline:none;line-height:1.4}.answer-line{display:flex;align-items:center;gap:10px;min-height:43px}.answer-line>span{color:var(--muted)}output{font-family:Manrope,Arial,sans-serif;font-size:32px;font-weight:600;letter-spacing:-1px;overflow-wrap:anywhere;text-align:right;flex:1}#feedback{font-size:10px;color:var(--muted);border-top:1px solid #8da37a33;margin-top:9px;padding-top:10px;line-height:1.5}#feedback.error{color:var(--danger)}.utility{display:flex;gap:6px;padding:12px 0}.utility button{font-size:10px;border:0;background:transparent;padding:6px 9px}.utility button:nth-child(3){margin-left:auto}.keys{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:7px}.keys button{height:44px;background:var(--key);border:1px solid transparent;border-radius:7px;font-size:15px;font-weight:500;box-shadow:0 2px 0 #24342907}.keys .number{background:var(--soft);font-size:20px}.keys .operator{background:#e8eddf;color:#293d2a;font-size:21px}.keys .equals{background:var(--accent);color:#233b22;font-size:24px}.keys .clear{color:#986a3f;background:#f2ece0}.keys .small{font-size:12px}.keys .shift.on{background:var(--accent);color:#233b22}.calc-footer{display:flex;justify-content:space-between;color:var(--muted);font-size:9px;padding-top:17px}.tabs{display:flex;border-bottom:1px solid var(--line);padding-bottom:0;gap:12px}.tabs button{background:transparent;border:0;border-radius:0;padding:16px 12px 17px;font-size:12px;color:var(--muted)}.tabs .active{color:var(--text);border-bottom:2px solid var(--text);font-weight:700}.tabs span{font-size:9px;background:var(--line);border-radius:5px;padding:2px 5px;margin-left:4px}#panel{min-height:360px;max-height:550px;overflow:auto;padding:19px 2px}.panel-heading{display:flex;justify-content:space-between;align-items:center;color:var(--muted);font-size:10px;letter-spacing:1px;margin-bottom:15px}.panel-heading button{font-size:10px;letter-spacing:0;border:0;background:transparent}.empty{display:flex;flex-direction:column;align-items:center;text-align:center;padding:48px 25px}.empty-icon{font-size:33px;color:#8e9e80;margin-bottom:16px}.empty strong{font-size:14px;font-weight:500}.empty p{font-size:12px;line-height:1.8;color:var(--muted);max-width:230px}.empty button{font-size:11px;margin-top:10px;background:var(--paper)}.record{background:var(--paper);border:1px solid var(--line);border-radius:10px;padding:14px;margin-bottom:10px}.record small{font-size:9px;color:var(--muted)}.record .expr{font-family:Consolas,monospace;font-size:13px;overflow-wrap:anywhere;margin:10px 0;color:var(--muted)}.record .value{font-size:21px;text-align:right;overflow-wrap:anywhere;margin-bottom:12px}.record .actions{display:flex;gap:5px}.record button{padding:5px 8px;font-size:10px;background:var(--soft)}.record strong{font-size:12px}.aside-note{border-top:1px solid var(--line);padding:22px 5px;display:flex;gap:13px}.aside-note>span{font-size:20px}.aside-note strong{font-size:12px;font-weight:500}.aside-note p{color:var(--muted);font-size:11px;line-height:1.8;margin:8px 0}.aside-note button,.import{font-size:10px;border:0;background:none;padding:5px 0;margin-right:15px;cursor:pointer}.import input{display:none}footer{display:flex;justify-content:space-between;font-size:10px;color:var(--muted);padding:29px 0 0}footer button{padding:0;border:0;background:none;font-size:10px;color:var(--muted)}dialog{max-width:540px;width:calc(100% - 30px);border:1px solid var(--line);border-radius:16px;padding:30px;background:var(--paper);color:var(--text)}dialog::backdrop{background:#16251ec0;backdrop-filter:blur(4px)}dialog h2{font-size:25px;font-family:Manrope;margin-top:3px}dialog p,dialog li{font-size:13px;line-height:1.8;color:var(--muted)}.close{float:right;border:0;font-size:22px}.tool-search,input.tool-input{width:100%;padding:11px;border:1px solid var(--line);border-radius:7px;background:var(--paper);color:var(--text);margin-bottom:12px}.tool-card{display:block;text-align:left;width:100%;margin-bottom:9px;padding:15px;background:var(--paper)}.tool-card strong{display:block;font-size:12px}.tool-card span{font-size:10px;color:var(--muted);display:block;margin-top:6px}.tool-form label{display:block;font-size:12px;margin-bottom:6px}.tool-form select{width:100%;padding:10px;margin-bottom:12px;color:var(--text);background:var(--paper);border:1px solid var(--line);border-radius:7px}.tool-result{background:var(--screen);padding:16px;margin-top:15px;line-height:1.8;overflow-wrap:anywhere;font-family:Consolas,monospace;font-size:14px}.primary{background:var(--accent);color:#203722}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}@media(min-width:1400px){main{padding-top:55px}.keys button{height:48px}}@media(max-width:850px){main{padding:30px 20px}.workspace{grid-template-columns:1fr 300px;gap:16px}.calculator{padding:15px}.brand-sub{display:none}.keys{gap:5px}.keys button{height:42px;font-size:13px}.keys .number{font-size:18px}.utility button{padding:6px 4px}.header-right>span{display:none}footer{gap:15px;flex-wrap:wrap}}@media(max-width:680px){header{height:70px;padding:0 20px}.brand{font-size:25px}.intro{margin-bottom:24px}h1{font-size:35px}.version{display:none}.eyebrow{font-size:8px}.workspace{grid-template-columns:1fr}.keys button{height:47px}.calculator{padding:15px}aside{margin-top:6px}#panel{min-height:200px;max-height:420px}.empty{padding:24px}.intro p:not(.eyebrow){font-size:12px}main{padding:26px 14px}.header-right{gap:7px}footer{line-height:1.6}.header-right button{padding:6px 9px}output{font-size:29px}}
/* Bubble palette: colourful surfaces with readable mathematical controls. */
:root{--bg:#faf4ff;--paper:#fffdfd;--text:#342452;--muted:#7c6b91;--line:#e5d8f4;--key:#f0e7ff;--accent:#c7f58d;--screen:#e9f5ff;--soft:#fff7e7}
body{background:radial-gradient(ellipse at 0% 20%,#e5d6ff 0,transparent 42%),radial-gradient(ellipse at 100% 65%,#ffd9eb 0,transparent 40%),linear-gradient(140deg,#f6efff,#effaff 55%,#fff1e7);min-height:100vh}body:before{content:'';position:fixed;z-index:-1;width:240px;height:240px;border-radius:50%;background:#ffd5ed80;top:130px;right:-100px;border:18px solid #ffffff50}header{background:#ffffffa8;backdrop-filter:blur(18px);border-bottom:1px solid #fff;box-shadow:0 5px 25px #6c409108}.mark{background:#8c63da;color:white;border-radius:15px;box-shadow:0 4px 0 #6d47b3}.brand{color:#54357f}.eyebrow{color:#9a5b99}.intro h1{color:#63408e}.intro h1:after{content:'✦';display:inline-block;color:#ef91bd;font-size:31px;margin-left:15px;vertical-align:middle}.version{background:#ffffff80;border-radius:30px;padding:5px 7px 5px 17px}.version b{background:#e8d9ff;border-radius:50%;border:0;color:#7250a2}.calculator{border-radius:30px;border:2px solid white;box-shadow:0 12px 0 #ded1ee70,0 22px 50px #75429d15;padding:24px;background:linear-gradient(150deg,#fff,#fff9fe)}.calc-heading>span{background:#f0e4ff;color:#8a60b6;border-radius:20px;padding:8px 12px}.calc-heading button,.calc-heading select{border-radius:18px;background:#f1e7ff}.screen{border-radius:22px;background:linear-gradient(135deg,#eaf5ff,#e9f9f1);border:2px solid #ddeafa;box-shadow:inset 0 3px 12px #98b6cb15}.screen-top{color:#688c94}textarea,output{color:#2b5266}#feedback{color:#688a91}.utility button{border-radius:18px;color:#8462a6}.utility button:hover{background:#f5eaff}.keys{gap:8px}.keys button{border-radius:17px;background:#eee5ff;color:#6d4a99;box-shadow:0 3px 0 #d9caed;transition:transform .12s,box-shadow .12s,background .12s}.keys button:hover{transform:translateY(-2px);filter:none;background:#e4d4ff}.keys button:active{transform:translateY(2px);box-shadow:0 1px 0 #d9caed}.keys .number{background:#fff4dd;color:#725842;box-shadow:0 3px 0 #eddfc4}.keys .number:hover{background:#ffe9ba}.keys .operator{background:#ffd9e8;color:#a4517c;box-shadow:0 3px 0 #ebbbcf}.keys .operator:hover{background:#ffc4dc}.keys .equals{background:#c7f19a;color:#4f753c;box-shadow:0 3px 0 #a6ce7d}.keys .equals:hover{background:#b9eb83}.keys .clear{background:#ffd9cd;color:#ad624e;box-shadow:0 3px 0 #eabeb0}.keys .shift.on{background:#d5f4a7}.calc-footer{color:#9c88b3}aside{background:#ffffff80;border:2px solid #fff;border-radius:28px;padding:10px 16px 2px;box-shadow:0 10px 30px #8251a009}.tabs{border:0;background:#eee4fa;border-radius:24px;padding:5px;gap:2px;justify-content:space-between}.tabs button{border-radius:20px;padding:10px 14px;font-weight:500;flex:1}.tabs .active{border:0;background:#fff;color:#8057aa;box-shadow:0 3px 8px #78529a12}.tabs span{background:#eee5fa;color:#926eb5}.panel-heading{padding:2px 7px;color:#9c83b2;font-size:9px}.record{border-radius:20px;border:1px solid #ebdff6;box-shadow:0 4px 0 #eae0f140;background:#fff}.record:nth-child(3n+2){background:#fff8ed;border-color:#f1e3cd}.record:nth-child(3n){background:#f0f9ff;border-color:#d9eaf5}.record .value{color:#70519b}.record button{border-radius:12px;background:#f5effc;border-color:#e7ddf2;color:#8963a8}.empty-icon{background:#e9ddfb;color:#9e78cf;border:7px solid #f4ebff;width:77px;height:77px;border-radius:27px;display:grid;place-items:center;transform:rotate(-8deg)}.empty strong{color:#79579a}.empty button{border-radius:20px;background:#f2e7ff;border:0;color:#8e63b4}.aside-note{border-color:#e7dbf2;padding:23px 8px}.aside-note>span{background:#ffe6ef;color:#ca80a3;width:34px;height:34px;flex-shrink:0;text-align:center;border-radius:13px;padding-top:3px}.aside-note strong{color:#926ea8}.aside-note button,.import{color:#a477bc}.tool-search,input.tool-input{border-radius:15px;background:#fff;border-color:#e6daf1}.tool-card{border-radius:19px;border-color:#e9ddf4;background:#fff}.tool-card:nth-child(even){background:#fff5e6}.tool-card:nth-child(3n){background:#edf8ff}.tool-card strong{color:#8b64ad}.header-right button{border-radius:16px;background:#f8efff;border-color:#eadcf5}.tool-result{white-space:pre-wrap;border-radius:18px}.primary{border-radius:18px;background:#d3efac;border:0;padding:12px 20px}dialog{border-radius:28px;border:2px solid #fff;box-shadow:0 15px 60px #684b872b;background:#fffafd}.local-dot{background:#c18ae8}.dark{--text:#f4eafa;--muted:#bdaaca;--line:#574261;--paper:#30243d;--key:#473255;--screen:#2a3d43;--soft:#3e3345;background:radial-gradient(at top left,#402955,transparent 60%),#211b2c}.dark header,.dark aside{background:#30243dc9;border-color:#564265}.dark .calculator{background:linear-gradient(140deg,#30243d,#392b46);border-color:#584167;box-shadow:0 12px 0 #140e2040}.dark .screen{background:linear-gradient(130deg,#2c3b52,#2b4646);border-color:#48516c}.dark textarea,.dark output{color:#def3f7}.dark .intro h1,.dark .brand{color:#e6c5ff}.dark .tabs{background:#453254}.dark .tabs .active,.dark .record,.dark .tool-card,.dark input.tool-input,.dark .tool-search{background:#3d2c4b;color:#f4eafa;border-color:#604876}.dark .record .value,.dark .tool-card strong,.dark .empty strong{color:#ddbbff}.dark .keys button{background:#594073;color:#f0dcff;box-shadow:0 3px 0 #271d35}.dark .keys .number{background:#594b3a;color:#ffe8be}.dark .keys .operator{background:#74435e;color:#ffd8e9}.dark .keys .equals{background:#aedb81;color:#2b4720}.dark dialog{background:#30243d}.dark .calc-heading>span,.dark .calc-heading button,.dark .calc-heading select{background:#594073;color:#f1ddff}@media(max-width:850px){.calculator{padding:16px}.keys{gap:6px}aside{padding:8px 10px}.tabs button{padding:10px}.utility button{font-size:9px}}@media(prefers-reduced-motion:reduce){.keys button{transition:none}}
#naturalExpression{min-height:42px;text-align:right;overflow-x:auto;overflow-y:hidden;padding:15px 0 4px;color:#304c64;font-size:27px}#naturalExpression math{margin-left:auto;width:max-content;max-width:100%}textarea{font-size:15px;min-height:29px;height:33px;margin-top:7px;line-height:1.4;opacity:.85}.screen{min-height:220px}.dark #naturalExpression{color:#def3f7}#feedback:empty{display:none}.intro{margin-bottom:26px}.calculator .keys button{font-family:'DM Sans',Arial,sans-serif}.calc-footer{line-height:1.5}@media(max-width:680px){#naturalExpression{font-size:26px}.screen{min-height:220px}main{padding-top:22px}.intro{margin-bottom:20px}}
.detail-block{padding:17px 0;border-bottom:1px solid var(--line)}.detail-block span{display:block;color:var(--muted);font-size:11px;margin-bottom:10px}.detail-block strong,.detail-math{font:19px Consolas,monospace;overflow-wrap:anywhere;white-space:pre-wrap}.graph-dialog{max-width:800px}.graph-wrap{margin-top:18px;border:1px solid #e5d9f1;border-radius:22px;overflow:hidden;background:#fffdfd}#plot{display:block;width:100%;height:auto;touch-action:pan-y}.graph-ranges{display:grid;grid-template-columns:1fr 1fr;gap:10px}.graph-ranges label{grid-row:1}.graph-ranges input{grid-row:2}.graph-caption{font-size:11px}.utility{flex-wrap:wrap}.utility button{white-space:nowrap}#graphRotation input{width:100%;accent-color:#a576d0}.graph-dialog h2{margin-bottom:15px}
.calculator,aside,.screen,#naturalExpression{min-width:0}#naturalExpression{width:100%;max-width:100%}#naturalExpression math{max-width:none}body{overflow-x:hidden}@media(max-width:680px){.workspace{grid-template-columns:minmax(0,1fr)}.calculator{width:100%}.calc-heading{gap:6px}.utility{gap:2px}.utility button{padding:6px 5px}.keys button{min-width:0}.intro h1{font-size:31px}}
textarea{resize:none;overflow-y:hidden;white-space:pre;scrollbar-width:thin}.dark .header-right button{background:#594073;color:#f3e2ff;border-color:#74548a}.dark #feedback,.dark .screen-top{color:#b5d0d1}.dark .utility button{color:#d2b5e9}.dark .calc-footer{color:#c1a9d3}.dark body:before{background:#875ca220}#naturalExpression{scrollbar-width:thin;scrollbar-color:#c7b2e1 transparent}
/* Scientific hardware layout: compact function bank, separate five-column keypad. */
#keys{display:block;padding:11px 10px 12px;background:linear-gradient(150deg,#3b315d,#2b2447);border:1px solid #554772;border-radius:12px;box-shadow:inset 0 1px 0 #ffffff20,0 5px 0 #d8cde6}.keypad-functions{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:2px 5px}.keypad-numbers{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:4px 7px;margin-top:10px;padding-top:7px;border-top:1px solid #a08cbc44}.key-cell{min-width:0}.key-secondary{height:17px;display:block;text-align:center;font:10px Arial,sans-serif;color:#d6b9ef;line-height:17px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;letter-spacing:.1px}.key-secondary.selected{color:#fff1a1}.calculator #keys button{display:block;width:100%;height:34px;padding:0 2px;border:1px solid #baa7d2;border-radius:4px;background:linear-gradient(#e9def7,#d5c4e9);color:#44305f;box-shadow:0 2px 0 #17102c;font-family:Arial,sans-serif;font-size:15px;font-weight:400;transition:filter .1s,transform .1s}.calculator #keys button:hover{background:linear-gradient(#faf4ff,#e6d3fa);transform:translateY(-1px);filter:none}.calculator #keys button:active{transform:translateY(2px);box-shadow:none}.calculator #keys .keypad-numbers button{height:48px;font-size:25px;border-radius:4px;background:linear-gradient(#67558b,#594778);color:#fff8ff;border-color:#86719f;box-shadow:0 3px 0 #170f2a}.calculator #keys .keypad-numbers button:hover{background:linear-gradient(#806aab,#70578f)}.calculator #keys .keypad-numbers .operator{background:linear-gradient(#f3c8d2,#e2afbe);color:#663e60;border-color:#f6d8e4}.calculator #keys .keypad-numbers .operator:hover{background:linear-gradient(#ffdeea,#f6c8d9)}.calculator #keys .keypad-numbers .equals{background:linear-gradient(#a0dfce,#82ccb8);color:#194f48;border-color:#b0e7dc}.calculator #keys .shift{background:linear-gradient(#b5e5d6,#8ed0ba);border-color:#c4eddf;color:#204c42;font-size:12px}.calculator #keys .shift.on{background:linear-gradient(#ffedb1,#f1ce73);border-color:#ffedb1;color:#594515}.calculator #keys .menu-key{background:linear-gradient(#d9c8ee,#c4abdf);font-size:12px}.calculator #keys .clear,.calculator #keys .delete-key{background:linear-gradient(#ffe2af,#f0c481);border-color:#ffe6bc;color:#70502a;font-size:13px}.calculator #keys .memory-key{color:#5b4393;background:linear-gradient(#e0d9f7,#cbc1ea);font-size:13px}.calculator #keys .small{font-size:11px}.calculator #keys .navigation-key{font-size:17px}.scientific-menu{display:grid;grid-template-columns:1fr 1fr;gap:8px}.scientific-menu .tool-card{margin:0;padding:13px}.calc-heading>span{letter-spacing:1.1px}.intro h1{font-size:35px}.intro h1:after{font-size:24px}.calculator{padding:20px}.calc-footer{font-size:9px}.dark #keys{border-color:#755e8c;box-shadow:inset 0 1px 0 #ffffff20,0 5px 0 #170f25;background:linear-gradient(150deg,#3b315d,#241e39)}.dark .calculator #keys .key-secondary{color:#ddc0f6}@media(max-width:680px){#keys{padding:7px 6px 10px}.keypad-functions{gap:1px 4px}.keypad-numbers{gap:2px 5px;margin-top:8px}.key-secondary{font-size:9px;height:17px;line-height:17px}.calculator #keys button{height:32px;font-size:13px}.calculator #keys .keypad-numbers button{height:43px;font-size:22px}.calculator #keys .memory-key{font-size:11px}.calculator #keys .small{font-size:10px}.calculator #keys .shift,.calculator #keys .menu-key{font-size:10px}.calculator{padding:13px}.intro h1{font-size:27px}.scientific-menu{grid-template-columns:1fr 1fr}.scientific-menu .tool-card{padding:10px}}