:root {
  --blue-950:#0b2240; --blue-900:#12335d; --blue-700:#1f5fae; --blue-600:#2673cf;
  --blue-500:#3b82d0; --blue-100:#eaf3ff; --blue-50:#f5f9ff; --ink:#172033;
  --muted:#5d6b80; --line:#dce5f0; --white:#fff; --success:#087f5b; --danger:#c0392b;
  --warning:#a15c00; --shadow:0 14px 38px rgba(31,67,110,.10); --radius:18px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:#f8fafc;color:var(--ink);font-family:Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.65}
button,input,select,textarea{font:inherit}
a{color:inherit}
.container{width:min(1140px,calc(100% - 2rem));margin-inline:auto}
.skip-link{position:fixed;left:1rem;top:-5rem;z-index:1000;background:var(--blue-950);color:#fff;padding:.7rem 1rem;border-radius:8px}
.skip-link:focus{top:1rem}
.site-header{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.96);backdrop-filter:blur(14px);border-bottom:1px solid rgba(220,229,240,.85)}
.nav-wrap{min-height:72px;display:flex;align-items:center;gap:1.5rem}
.brand{display:flex;align-items:center;gap:.65rem;text-decoration:none;font-weight:800;color:var(--blue-950);line-height:1.05;white-space:nowrap}
.brand-mark{display:grid;place-items:center;width:38px;height:38px;border-radius:11px;background:linear-gradient(145deg,var(--blue-700),#45a2ed);color:#fff;font-family:Georgia,serif;font-size:1.25rem}
.brand small{display:block;color:var(--blue-600);font-weight:600;font-size:.64rem;letter-spacing:.05em}
.main-nav{display:flex;align-items:center;gap:.15rem;margin-left:auto}
.main-nav a,.nav-dropdown>button{border:0;background:none;text-decoration:none;padding:.62rem .72rem;border-radius:9px;color:#40516a;font-weight:600;font-size:.88rem;cursor:pointer}
.main-nav a:hover,.main-nav a[aria-current="page"],.nav-dropdown>button:hover{background:var(--blue-50);color:var(--blue-700)}
.nav-dropdown{position:relative}
.dropdown-menu{display:none;position:absolute;right:0;top:calc(100% + .4rem);width:290px;padding:.5rem;background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow)}
.nav-dropdown.open .dropdown-menu{display:grid}
.dropdown-menu a{padding:.55rem .7rem}
.nav-toggle{display:none;margin-left:auto;border:1px solid var(--line);background:#fff;border-radius:10px;padding:.45rem .65rem;font-size:1.2rem}
.home-hero{overflow:hidden;background:linear-gradient(120deg,#f7fbff 0%,#edf5ff 55%,#e7f2ff 100%);padding:6.2rem 0 5.4rem;border-bottom:1px solid var(--line)}
.hero-grid{display:grid;grid-template-columns:1.08fr .92fr;gap:5rem;align-items:center}
.eyebrow{display:inline-block;color:var(--blue-600);font-size:.74rem;letter-spacing:.16em;text-transform:uppercase;font-weight:800;margin-bottom:.7rem}
h1,h2,h3{color:var(--blue-950);line-height:1.18}
h1{font-size:clamp(2.5rem,5vw,4.4rem);letter-spacing:-.045em;margin:.2rem 0 1.25rem}
h1 span{color:var(--blue-600)}
h2{font-size:clamp(1.8rem,3vw,2.6rem);letter-spacing:-.025em;margin:.1rem 0 .65rem}
h3{margin:.25rem 0 .55rem}
.lead{font-size:1.16rem;color:var(--muted);max-width:650px}
.button-row{display:flex;gap:.75rem;flex-wrap:wrap;margin-top:1.8rem}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;border:1px solid transparent;border-radius:11px;padding:.76rem 1.08rem;font-weight:750;text-decoration:none;cursor:pointer;transition:.18s ease}
.btn:hover{transform:translateY(-1px);box-shadow:0 8px 20px rgba(22,71,128,.14)}
.btn:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,button:focus-visible,a:focus-visible{outline:3px solid rgba(38,115,207,.28);outline-offset:2px}
.btn-primary{background:var(--blue-700);color:#fff}.btn-primary:hover{background:var(--blue-900)}
.btn-secondary{background:#fff;color:var(--blue-700);border-color:#cbd9e9}
.btn-ghost{color:var(--blue-700);background:transparent;border-color:var(--line)}
.btn-danger{color:var(--danger);background:#fff;border-color:#efc9c5}
.hero-stats{display:flex;gap:2.5rem;margin-top:2.4rem}
.hero-stats div{display:grid}.hero-stats strong{color:var(--blue-950);font-size:1.3rem}.hero-stats span{color:var(--muted);font-size:.8rem}
.hero-visual{position:relative;min-height:360px;display:grid;place-items:center}
.chart-card{width:min(420px,92%);height:275px;background:rgba(255,255,255,.9);padding:1.4rem;border:1px solid #d7e5f5;border-radius:24px;box-shadow:0 28px 65px rgba(32,84,145,.18);transform:rotate(-1deg)}
.chart-head{display:flex;justify-content:space-between;font-weight:700;color:var(--blue-950)}
.badge{color:var(--success);background:#e7f8f2;border-radius:99px;padding:.2rem .55rem;font-size:.75rem}
.chart-bars{height:175px;display:flex;align-items:end;justify-content:space-around;border-bottom:1px solid var(--line);margin-top:1rem;background:repeating-linear-gradient(to top,transparent 0,transparent 43px,#e8eef5 44px)}
.chart-bars i{display:block;width:10%;background:linear-gradient(to top,var(--blue-700),#67b2ed);border-radius:6px 6px 0 0}
.chart-labels{display:flex;justify-content:space-between;color:var(--muted);font-size:.75rem;margin-top:.45rem}
.formula-float{position:absolute;z-index:2;background:var(--blue-950);color:#fff;padding:.75rem 1rem;border-radius:12px;box-shadow:var(--shadow);font-family:Georgia,serif}
.formula-a{right:-1rem;top:1rem}.formula-b{left:-1rem;bottom:.6rem;background:#fff;color:var(--blue-950);border:1px solid var(--line)}
.section{padding:5.2rem 0}
.section-heading{max-width:690px;margin-bottom:2rem}.section-heading>p{color:var(--muted);margin-top:.4rem}
.module-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:1.15rem}
.module-card{position:relative;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:1.45rem;box-shadow:0 3px 12px rgba(20,48,81,.04);transition:.2s ease;min-height:250px;display:flex;flex-direction:column}
.module-card:hover{transform:translateY(-4px);border-color:#b9d1ed;box-shadow:var(--shadow)}
.module-number{position:absolute;right:1.2rem;top:1.15rem;color:#b3c0cf;font-size:.78rem;font-weight:800}
.module-icon{display:grid;place-items:center;width:44px;height:44px;border-radius:12px;background:var(--blue-100);color:var(--blue-700);font-weight:800;font-size:1.05rem;margin-bottom:.9rem}
.module-card p{color:var(--muted);font-size:.91rem;margin:0 0 1.2rem}
.module-card a{margin-top:auto;text-decoration:none;color:var(--blue-700);font-size:.88rem;font-weight:750}
.module-card a span{transition:.15s}.module-card:hover a span{margin-left:.3rem}
.module-card-featured{background:linear-gradient(145deg,var(--blue-950),#1d4b80);border:0}.module-card-featured h3,.module-card-featured p,.module-card-featured a{color:#fff}.module-card-featured p{opacity:.78}.module-card-featured .module-icon{background:rgba(255,255,255,.14);color:#fff}
.learning-strip{background:var(--blue-950);color:#fff;padding:3.4rem 0}.learning-strip h2{color:#fff}.strip-grid{display:grid;grid-template-columns:.7fr 1.3fr;gap:3rem;align-items:center}
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:1rem;padding:0;margin:0;list-style:none}
.steps li{display:flex;align-items:center;gap:.75rem}.steps li>span{display:grid;place-items:center;flex:0 0 38px;height:38px;border-radius:50%;background:rgba(255,255,255,.12);color:#72baff;font-weight:800}.steps div{display:grid}.steps small{opacity:.65}
.about-section{padding:4.5rem 0;background:#f8fafc;scroll-margin-top:80px}.about-card{display:grid;grid-template-columns:auto minmax(0,1fr) auto;gap:1.5rem;align-items:center;background:#fff;border:1px solid var(--line);border-radius:22px;padding:2rem;box-shadow:var(--shadow)}.about-mark{display:grid;place-items:center;width:74px;height:74px;border-radius:20px;background:linear-gradient(145deg,var(--blue-700),#45a2ed);color:#fff;font-size:1.35rem;font-weight:850;letter-spacing:.04em}.about-copy h2{font-size:1.7rem;margin:0 0 .6rem}.about-copy p{color:var(--muted);margin:0;max-width:700px}.about-contact{display:grid;gap:.3rem;background:var(--blue-50);border:1px solid #d9e7f6;border-radius:14px;padding:1rem 1.15rem}.about-contact span{color:var(--muted);font-size:.72rem;text-transform:uppercase;letter-spacing:.08em;font-weight:800}.about-contact a{color:var(--blue-700);font-size:.86rem;font-weight:750;text-decoration:none;overflow-wrap:anywhere}.about-contact a:hover{text-decoration:underline}
.page-hero{background:linear-gradient(120deg,var(--blue-950),#1b4e84);color:#fff;padding:3.4rem 0 3rem}
.breadcrumbs{font-size:.78rem;opacity:.7;margin-bottom:1.2rem}.breadcrumbs a{text-decoration:none}.breadcrumbs span{margin:0 .45rem}
.page-hero h1{color:#fff;font-size:clamp(2.2rem,4vw,3.35rem);margin:.2rem 0 .85rem;letter-spacing:-.035em}
.page-hero p{max-width:760px;color:#d5e4f4;font-size:1.05rem}
.objective{display:flex;gap:.75rem;align-items:flex-start;margin-top:1.4rem;padding:1rem 1.1rem;border-radius:13px;background:rgba(255,255,255,.1);max-width:850px;font-size:.9rem}.objective strong{color:#7ec0ff;white-space:nowrap}
.lesson-layout{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:2.5rem;align-items:start}
.lesson-content{min-width:0}.lesson-content>section{scroll-margin-top:96px;margin-bottom:3.8rem}
.lesson-content h2{font-size:1.75rem;border-bottom:1px solid var(--line);padding-bottom:.65rem}
.lesson-content p,.lesson-content li{color:#46566d}
.lesson-content strong{color:var(--ink)}
.side-index{position:sticky;top:96px;background:#fff;border:1px solid var(--line);border-radius:15px;padding:1rem}
.side-index strong{display:block;color:var(--blue-950);font-size:.82rem;margin-bottom:.55rem}.side-index a{display:block;text-decoration:none;color:var(--muted);font-size:.83rem;padding:.35rem .45rem;border-left:2px solid var(--line)}.side-index a:hover{color:var(--blue-700);border-left-color:var(--blue-600)}
.formula-box{background:linear-gradient(120deg,#eef6ff,#f8fbff);border-left:4px solid var(--blue-600);border-radius:0 14px 14px 0;padding:1.3rem 1.5rem;margin:1.2rem 0}
.formula{font-family:Cambria,Georgia,serif;color:var(--blue-950);font-size:1.45rem;text-align:center;margin:.6rem 0}
.formula-legend{font-size:.86rem;color:var(--muted);display:flex;gap:1rem;justify-content:center;flex-wrap:wrap}
.callout{display:flex;gap:.8rem;background:#fff9e8;border:1px solid #f0dfa9;border-radius:13px;padding:1rem 1.1rem;margin:1.2rem 0}.callout.info{background:#edf7ff;border-color:#c6e2f7}.callout strong{color:var(--warning)}
.worked-example{background:#fff;border:1px solid var(--line);border-radius:16px;padding:1.4rem;box-shadow:0 4px 16px rgba(29,58,92,.05)}
.worked-example h3{font-size:1rem;color:var(--blue-700)}.calculation{font-family:Cambria,Georgia,serif;background:#f5f7fa;padding:.85rem;border-radius:9px;color:var(--blue-950)}
.simulator{background:#fff;border:1px solid #cfddeb;border-radius:20px;box-shadow:var(--shadow);overflow:hidden}
.simulator-head{padding:1.4rem 1.5rem;background:var(--blue-950);color:#fff}.simulator-head h3{color:#fff;margin:0}.simulator-head p{color:#c6d7ea;margin:.3rem 0 0;font-size:.9rem}
.simulator-body{padding:1.5rem}
.form-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem}
.form-grid.cols-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.field{display:grid;gap:.35rem}.field.full{grid-column:1/-1}.field label,.field>span{font-size:.82rem;font-weight:700;color:#394b63}
.field input,.field select,.field textarea{width:100%;border:1px solid #cbd7e5;border-radius:9px;padding:.7rem .8rem;background:#fff;color:var(--ink)}
.field input:focus,.field select:focus,.field textarea:focus{border-color:var(--blue-600)}
.field small{font-size:.74rem;color:var(--muted)}
.form-actions{grid-column:1/-1;display:flex;gap:.7rem;align-items:center;margin-top:.25rem}
.error-message{color:var(--danger);font-size:.85rem;font-weight:600;min-height:1.3em}
.result-area{margin-top:1.4rem}.result-area:empty{display:none}
.result-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:.75rem}
.result-card{background:var(--blue-50);border:1px solid #d9e7f6;border-radius:12px;padding:.9rem}.result-card span{display:block;color:var(--muted);font-size:.72rem;text-transform:uppercase;letter-spacing:.06em}.result-card strong{display:block;color:var(--blue-950);font-size:1.1rem;margin-top:.2rem}
.result-card.success{background:#eaf8f3;border-color:#c3e9db}.result-card.danger{background:#fff0ef;border-color:#efcfcb}
.table-wrap{overflow-x:auto;margin-top:1rem;border:1px solid var(--line);border-radius:10px}
table{width:100%;border-collapse:collapse;min-width:610px;background:#fff;font-size:.83rem}th,td{padding:.62rem .7rem;border-bottom:1px solid #e7edf4;text-align:right;white-space:nowrap}th{background:#f3f7fb;color:#43536a;font-size:.73rem;text-transform:uppercase;letter-spacing:.04em}th:first-child,td:first-child{text-align:left}tbody tr:hover{background:#fafcff}
.comparison-bars{display:grid;gap:.75rem;margin-top:1rem}.bar-row{display:grid;grid-template-columns:125px 1fr 120px;gap:.75rem;align-items:center;font-size:.8rem}.bar-track{height:10px;border-radius:99px;background:#e3ebf4;overflow:hidden}.bar-fill{height:100%;background:var(--blue-600);border-radius:99px}
.dynamic-list{display:grid;gap:.65rem}.dynamic-row{display:grid;grid-template-columns:1fr 1fr auto;gap:.55rem;align-items:end}.dynamic-row .btn{padding:.58rem .75rem}
.flow-columns{display:grid;grid-template-columns:1fr 1fr;gap:1rem}.flow-box{border:1px solid var(--line);padding:1rem;border-radius:12px}.flow-box h4{margin:0 0 .7rem;color:var(--blue-950)}
.exercises{display:grid;gap:.75rem;counter-reset:exercise}.exercise{position:relative;background:#fff;border:1px solid var(--line);border-radius:12px;padding:1rem 1rem 1rem 3.4rem}.exercise:before{counter-increment:exercise;content:counter(exercise);position:absolute;left:1rem;top:1rem;display:grid;place-items:center;width:27px;height:27px;border-radius:50%;background:var(--blue-100);color:var(--blue-700);font-weight:800}.exercise p{margin:0}
.topic-nav{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:.75rem;border-top:1px solid var(--line);padding-top:1.5rem}.topic-nav a{text-decoration:none;color:var(--blue-700);font-weight:700;font-size:.85rem}.topic-nav a:last-child{text-align:right}
.site-footer{background:#081d36;color:#bdcada;padding:2.4rem 0}.footer-grid{display:flex;justify-content:space-between;gap:2rem;align-items:center}.footer-grid p{font-size:.8rem;margin:.25rem 0}.footer-links{display:flex;gap:1rem;flex-wrap:wrap}.footer-links a{font-size:.8rem;text-decoration:none}.footer-email{color:#dbeaff;text-decoration:none}.footer-email:hover{text-decoration:underline}
.plan-tabs{display:flex;gap:.4rem;flex-wrap:wrap;margin:1.2rem 0}.plan-tabs button{border:1px solid var(--line);background:#fff;color:var(--blue-700);padding:.5rem .75rem;border-radius:8px;font-weight:700;cursor:pointer}.plan-tabs button.active{background:var(--blue-700);color:#fff;border-color:var(--blue-700)}
.hp-calculator-scroll{overflow-x:auto;padding:.3rem .2rem 1rem}.hp-calculator-actions{display:flex;justify-content:flex-end;width:min(780px,100%);margin:0 auto .55rem}.hp-fullscreen-button{display:inline-flex;align-items:center;justify-content:center;gap:.4rem;border:1px solid #c5d4e5;border-radius:9px;padding:.48rem .72rem;background:#fff;color:var(--blue-700);font-size:.78rem;font-weight:800;cursor:pointer;box-shadow:0 3px 10px rgba(20,48,81,.08)}.hp-fullscreen-button:hover{background:var(--blue-50);border-color:#9bbbe0}.hp-fullscreen-button span[aria-hidden="true"]{font-size:1rem;line-height:1}.hp-shell{min-width:700px;max-width:780px;margin:auto;overflow:hidden;background:#24272d;border:5px solid #5c6066;border-radius:8px;box-shadow:0 24px 55px rgba(0,0,0,.28),inset 0 0 0 2px #111}
.hp-top-panel{padding:1rem 1.35rem .8rem;background:linear-gradient(150deg,#dfd9bd,#bdb79e);border-bottom:7px solid #17191d}
.hp-brand{display:flex;justify-content:space-between;align-items:center;color:#2a2a27;margin-bottom:.65rem;font-size:.7rem;font-weight:800;letter-spacing:.22em}.hp-brand small{display:block;font-size:.48rem;letter-spacing:.12em;color:#5c5a50}.hp-logo{display:grid;place-items:center;width:48px;height:48px;border-radius:5px;background:#26241f;color:#ebd38b;line-height:.78;text-align:center;font-family:Georgia,serif;font-size:1rem;letter-spacing:0}.hp-logo b{font-family:Arial,sans-serif;font-size:.72rem}
.hp-display-frame{width:76%;margin:0 auto;background:#c5aa68;border-radius:8px;padding:.38rem;box-shadow:inset 0 1px 2px rgba(255,255,255,.7)}.hp-display{position:relative;min-height:86px;overflow:hidden;background:#bfc3b2;border:2px solid #55584e;border-radius:5px;padding:.55rem .8rem .35rem;text-align:right;color:#11170e;font-family:"Courier New",monospace;box-shadow:inset 0 2px 6px rgba(0,0,0,.2)}#hpDisplayValue{overflow-x:auto;font-family:"Courier New",monospace;font-size:2.55rem;font-weight:700;line-height:1;letter-spacing:.05em;white-space:nowrap}.hp-annunciators{display:flex;justify-content:space-between;min-height:1rem;font-family:Arial,sans-serif;font-size:.6rem;font-weight:800}.hp-status{min-height:.85rem;margin-top:.2rem;text-align:left;font-family:Arial,sans-serif;font-size:.58rem;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.hp-registers{display:grid;grid-template-columns:repeat(5,1fr);gap:.35rem;margin:.7rem auto 0;width:92%;font-size:.62rem;color:#34342f}.hp-registers div{min-width:0;padding:.25rem .35rem;border:1px solid rgba(50,50,45,.25);border-radius:4px;background:rgba(255,255,255,.18);text-align:center}.hp-registers strong{display:block;overflow:hidden;color:#171a18;text-overflow:ellipsis;white-space:nowrap}
.hp-keyboard{padding:1.35rem 1.15rem 1rem;background:linear-gradient(145deg,#252830,#17191e)}.hp-keys{display:grid;grid-template-columns:repeat(10,minmax(0,1fr));gap:.72rem .6rem}.hp-key{position:relative;min-height:58px;border:1px solid #07080a;border-radius:5px;padding:.8rem .2rem .65rem;background:linear-gradient(#3d424d,#262a33);color:#f3f5fa;box-shadow:0 3px 0 #090a0d,0 4px 8px rgba(0,0,0,.45);font-weight:800;cursor:pointer;transition:transform .08s ease,filter .12s ease}.hp-key:hover{filter:brightness(1.16)}.hp-key:active{transform:translateY(2px);box-shadow:0 1px 0 #090a0d}.key-main{display:block;font-size:1.05rem;line-height:1.05}.key-top,.key-bottom{position:absolute;left:2px;right:2px;font-size:.48rem;line-height:1;white-space:nowrap}.key-top{top:.2rem;color:#ef9b35}.key-bottom{bottom:.2rem;color:#36b9e9}.operator-key .key-main{font-size:1.45rem}.financial-key .key-main{font-size:1.12rem}.prefix-f{background:linear-gradient(#e1a563,#bd7138);color:#35200d}.prefix-g{background:linear-gradient(#38bbda,#167f9f);color:#072d38}.prefix-f .key-main,.prefix-g .key-main{font-size:1.3rem}.hp-enter{grid-column:6;grid-row:3/span 2;min-height:126px}.hp-enter .key-main{font-size:.8rem;line-height:1.07;letter-spacing:.05em}.hp-help{margin:.9rem 0 0;color:#bec7d5;text-align:center;font-size:.72rem}.hp-help strong:first-of-type{color:#ef9b35}.hp-help strong:last-of-type{color:#36b9e9}
.hp-calculator-scroll:fullscreen,.hp-calculator-scroll.hp-fullscreen-fallback{width:100%;height:100%;max-width:none;margin:0;padding:.75rem;background:#101216;overflow:auto}.hp-calculator-scroll:fullscreen .hp-calculator-actions,.hp-calculator-scroll.hp-fullscreen-fallback .hp-calculator-actions{width:min(780px,100%)}.hp-calculator-scroll:fullscreen .hp-fullscreen-button,.hp-calculator-scroll.hp-fullscreen-fallback .hp-fullscreen-button{border-color:#4e5968;background:#262b34;color:#fff}.hp-calculator-scroll:fullscreen .hp-shell,.hp-calculator-scroll.hp-fullscreen-fallback .hp-shell{width:min(780px,100%)}.hp-calculator-scroll.hp-fullscreen-fallback{position:fixed;inset:0;z-index:1000}.hp-fullscreen-open{overflow:hidden}
@media(max-width:960px){.main-nav{display:none;position:absolute;left:1rem;right:1rem;top:68px;background:#fff;border:1px solid var(--line);border-radius:12px;padding:.6rem;box-shadow:var(--shadow);align-items:stretch;flex-direction:column}.main-nav.open{display:flex}.nav-toggle{display:block}.nav-dropdown>button{text-align:left;width:100%}.dropdown-menu{position:static;width:auto;box-shadow:none;margin-top:.3rem}.hero-grid{grid-template-columns:1fr;gap:3rem}.hero-visual{min-height:300px}.module-grid{grid-template-columns:repeat(2,1fr)}.lesson-layout{grid-template-columns:1fr}.side-index{display:none}.strip-grid{grid-template-columns:1fr}.steps{margin-top:.5rem}}
@media(max-width:680px){.home-hero{padding:4rem 0}.hero-visual{display:none}.hero-stats{gap:1.4rem}.module-grid{grid-template-columns:1fr}.section{padding:3.6rem 0}.steps{grid-template-columns:1fr}.about-card{grid-template-columns:1fr}.about-mark{width:60px;height:60px}.form-grid,.form-grid.cols-3,.result-grid,.flow-columns{grid-template-columns:1fr}.dynamic-row{grid-template-columns:1fr 1fr}.dynamic-row .btn{grid-column:1/-1}.topic-nav{grid-template-columns:1fr 1fr}.topic-nav .home-link{grid-column:1/-1;grid-row:1;text-align:center}.bar-row{grid-template-columns:95px 1fr}.bar-row strong{grid-column:2}.footer-grid{align-items:flex-start;flex-direction:column}.formula-a,.formula-b{display:none}}
@media(max-width:680px){
  .hp-calculator-scroll{margin-inline:-.5rem;padding:.2rem 0 .8rem;overflow-x:hidden}
  .hp-calculator-actions{padding-inline:.2rem}
  .hp-fullscreen-button{padding:.42rem .62rem;font-size:.72rem}
  .hp-shell{width:100%;min-width:0;max-width:none;border-width:3px;border-radius:6px;box-shadow:0 14px 30px rgba(0,0,0,.24),inset 0 0 0 1px #111}
  .hp-top-panel{padding:.65rem .5rem .5rem;border-bottom-width:4px}
  .hp-brand{margin-bottom:.45rem;font-size:.5rem;letter-spacing:.08em}
  .hp-brand small{font-size:.36rem;letter-spacing:.05em}
  .hp-logo{width:34px;height:34px;font-size:.72rem}
  .hp-logo b{font-size:.52rem}
  .hp-display-frame{width:94%;padding:.25rem;border-radius:5px}
  .hp-display{min-height:66px;padding:.35rem .45rem .25rem}
  #hpDisplayValue{font-size:clamp(1.45rem,8vw,2rem);letter-spacing:.02em}
  .hp-annunciators{font-size:.48rem}
  .hp-status{font-size:.46rem}
  .hp-registers{width:100%;gap:.15rem;margin-top:.45rem;font-size:.48rem}
  .hp-registers div{padding:.16rem .05rem}
  .hp-keyboard{padding:.75rem .35rem .65rem}
  .hp-keys{gap:.5rem .2rem}
  .hp-key{min-width:0;min-height:45px;border-radius:4px;padding:.65rem 0 .55rem;box-shadow:0 2px 0 #090a0d,0 3px 5px rgba(0,0,0,.4);touch-action:manipulation}
  .key-main{font-size:clamp(.55rem,2.5vw,.78rem)}
  .key-top,.key-bottom{left:0;right:0;font-size:clamp(.25rem,1.15vw,.38rem);letter-spacing:-.02em}
  .key-top{top:.15rem}
  .key-bottom{bottom:.14rem}
  .operator-key .key-main{font-size:clamp(.8rem,3.2vw,1.05rem)}
  .financial-key .key-main{font-size:clamp(.53rem,2.35vw,.72rem)}
  .prefix-f .key-main,.prefix-g .key-main{font-size:clamp(.75rem,3vw,.95rem)}
  .hp-enter{min-height:98px}
  .hp-enter .key-main{font-size:.58rem}
  .hp-help{font-size:.62rem;line-height:1.45}
}
@media(orientation:landscape) and (max-height:600px){
  .hp-calculator-scroll:fullscreen,.hp-calculator-scroll.hp-fullscreen-fallback{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:.25rem;overflow:hidden}
  .hp-calculator-scroll:fullscreen .hp-calculator-actions,.hp-calculator-scroll.hp-fullscreen-fallback .hp-calculator-actions{flex:0 0 auto;width:min(720px,100%);margin:0 auto .2rem}
  .hp-calculator-scroll:fullscreen .hp-fullscreen-button,.hp-calculator-scroll.hp-fullscreen-fallback .hp-fullscreen-button{padding:.25rem .5rem;font-size:.65rem}
  .hp-calculator-scroll:fullscreen .hp-shell,.hp-calculator-scroll.hp-fullscreen-fallback .hp-shell{flex:0 1 auto;width:min(720px,100%);min-width:0;border-width:3px;border-radius:6px}
  .hp-calculator-scroll:fullscreen .hp-top-panel,.hp-calculator-scroll.hp-fullscreen-fallback .hp-top-panel{padding:.35rem .55rem .3rem;border-bottom-width:4px}
  .hp-calculator-scroll:fullscreen .hp-brand,.hp-calculator-scroll.hp-fullscreen-fallback .hp-brand{display:none}
  .hp-calculator-scroll:fullscreen .hp-display-frame,.hp-calculator-scroll.hp-fullscreen-fallback .hp-display-frame{width:78%;padding:.2rem}
  .hp-calculator-scroll:fullscreen .hp-display,.hp-calculator-scroll.hp-fullscreen-fallback .hp-display{min-height:49px;padding:.2rem .45rem .15rem}
  .hp-calculator-scroll:fullscreen #hpDisplayValue,.hp-calculator-scroll.hp-fullscreen-fallback #hpDisplayValue{font-size:1.6rem}
  .hp-calculator-scroll:fullscreen .hp-annunciators,.hp-calculator-scroll.hp-fullscreen-fallback .hp-annunciators{min-height:.7rem;font-size:.46rem}
  .hp-calculator-scroll:fullscreen .hp-status,.hp-calculator-scroll.hp-fullscreen-fallback .hp-status{min-height:.6rem;margin-top:.05rem;font-size:.43rem}
  .hp-calculator-scroll:fullscreen .hp-registers,.hp-calculator-scroll.hp-fullscreen-fallback .hp-registers{width:100%;gap:.2rem;margin-top:.25rem;font-size:.45rem}
  .hp-calculator-scroll:fullscreen .hp-registers div,.hp-calculator-scroll.hp-fullscreen-fallback .hp-registers div{padding:.08rem .12rem}
  .hp-calculator-scroll:fullscreen .hp-keyboard,.hp-calculator-scroll.hp-fullscreen-fallback .hp-keyboard{padding:.4rem .45rem .35rem}
  .hp-calculator-scroll:fullscreen .hp-keys,.hp-calculator-scroll.hp-fullscreen-fallback .hp-keys{gap:.3rem .25rem}
  .hp-calculator-scroll:fullscreen .hp-key,.hp-calculator-scroll.hp-fullscreen-fallback .hp-key{min-height:42px;padding:.62rem .08rem .52rem}
  .hp-calculator-scroll:fullscreen .hp-enter,.hp-calculator-scroll.hp-fullscreen-fallback .hp-enter{min-height:89px}
  .hp-calculator-scroll:fullscreen .hp-help,.hp-calculator-scroll.hp-fullscreen-fallback .hp-help{display:none}
}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}