@media(max-width:900px){.nav-toggle{display:block;margin-left:auto}.theme-toggle{order:2}.nav-links{display:none;position:absolute;top:74px;left:0;right:0;margin:0;padding:1rem 20px;background:var(--surface);border-bottom:1px solid var(--border);flex-direction:column;align-items:stretch}.nav-links.open{display:flex}.nav-links>a,.nav-dropdown>summary{padding:.75rem}.dropdown-panel{position:static;width:100%;box-shadow:none;margin-top:.3rem}.hero{grid-template-columns:1fr;padding-block:4rem;gap:3rem}.hero-visual{min-height:390px}.why-grid,.learn-panel{grid-template-columns:1fr;gap:2rem}.tool-workspace{grid-template-columns:1fr}.graph-workspace{grid-template-columns:1fr}.graph-controls{display:grid;grid-template-columns:1fr 1fr;column-gap:1rem}.graph-controls h2,.graph-controls #function-list,.graph-controls #add-function,.graph-controls .examples,.graph-controls .button-row,.graph-controls #reset-view{grid-column:1/-1}.calculator-layout{grid-template-columns:1fr}.scientific-shell{max-width:none}.footer-grid{grid-template-columns:1.5fr 1fr 1fr}}
@media(max-width:650px){.container{width:min(calc(100% - 24px),var(--container))}.nav{gap:.5rem}.theme-toggle{width:44px;padding:0;justify-content:center}.theme-label{display:none}.hero{min-height:auto;padding-block:3.2rem}.hero h1{font-size:clamp(2.7rem,14vw,4.2rem)}.hero-lead{font-size:1.05rem}.hero-actions .btn{width:100%}.hero-visual{min-height:330px}.hero-visual svg{height:280px}.visual-caption{font-size:.62rem;gap:.35rem}.section-gap{margin-block:4.5rem}.section-heading{display:block}.tool-grid{grid-template-columns:1fr}.tool-card.featured{grid-row:auto}.why-section{padding:4.5rem 0}.learn-panel{padding:1.4rem}.footer-grid{grid-template-columns:1fr}.footer-bottom{display:block}.footer-bottom span{display:block}.tool-page{padding-top:1rem}.tool-heading{margin:1.2rem 0 1.6rem}.tool-heading h1{font-size:2.35rem}.math-input-row{grid-template-columns:1fr}.math-input-row .btn{width:100%}.fraction-entry{grid-template-columns:1fr}.two-inputs{grid-template-columns:1fr}.tool-info{grid-template-columns:1fr;gap:2rem}.input-card,.result-card{padding:1rem}.graph-controls{display:block}#graph{height:470px}.graph-export-bar .btn{flex:1}.calc-keys{gap:.3rem}.calc-keys button{min-height:45px;font-size:.85rem}.history-card{display:none}.prose-page{padding-block:3.5rem}.prose-page>h1{font-size:2.7rem}}
@media(max-width:380px){.brand{font-size:1rem}.brand-mark{width:32px;height:32px}.nav-toggle,.theme-toggle{width:40px}.calc-keys button{font-size:.78rem;padding:0}.tool-card{padding:1.1rem}.tool-icon{width:48px;height:48px}}