/* Small launcher; comfortable touch targets and independent scrolling. */
.calculator-launcher,.search-launcher{position:fixed;left:12px;bottom:calc(var(--tools-bottom,14px) + env(safe-area-inset-bottom));z-index:48;width:44px;height:44px;display:grid;place-items:center;border:1px solid var(--line);border-radius:12px;background:var(--surface);color:var(--brand);box-shadow:var(--shadow);cursor:pointer}
.learning-dialog{color:var(--ink);background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:16px;box-shadow:var(--shadow);max-height:calc(var(--zoom-view-height,90vh) - 84px);overflow:auto;box-sizing:border-box}
.learning-dialog::backdrop{background:rgba(16,30,50,.35)}
.learning-dialog button,.learning-dialog input,.learning-dialog select{font:inherit}
.tool-heading{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-bottom:12px}
.tool-heading h2{font-size:1.15rem;margin:0}
.tool-close{min-width:44px;min-height:44px;border:1px solid var(--line);border-radius:10px;background:var(--surface);color:var(--ink);font-size:24px!important;cursor:pointer}
.calculator-panel{position:fixed;inset:auto auto calc(var(--tools-bottom,14px) + 52px + env(safe-area-inset-bottom)) 12px;margin:0;width:320px;max-width:calc(var(--zoom-view-width,100vw) - 24px);z-index:65}
.learning-dialog input,.learning-dialog select{width:100%;box-sizing:border-box;min-height:44px;border:1px solid var(--line);border-radius:8px;padding:10px;background:var(--surface);color:var(--ink);margin:8px 0}
.calculator-output{display:block;min-height:44px;padding:10px 0;overflow-wrap:anywhere;font-weight:700}
.calculator-keys{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:7px}
.calculator-keys button{min-height:44px;border:1px solid var(--line);border-radius:9px;background:var(--surface-2);color:var(--ink);cursor:pointer}
.calculator-keys button:last-child{background:var(--brand);color:white}
.tool-hint{font-size:.8rem;line-height:1.5}.tool-error{color:var(--bad,#b42318)}
.calculator-history button{display:block;text-align:left;width:100%;padding:8px;background:var(--surface);color:var(--ink);border:0;border-bottom:1px solid var(--line);overflow-wrap:anywhere;cursor:pointer}
.search-panel{width:640px;max-width:calc(var(--zoom-view-width,100vw) - 24px)}
.search-results a{display:flex;flex-direction:column;gap:4px;padding:14px 4px;border-bottom:1px solid var(--line);text-decoration:none;color:var(--ink)}
.search-results small{color:var(--ink-2)}.search-results a:hover{background:var(--surface-2)}
.constant-help{border-inline-start:3px solid var(--brand);background:var(--surface-2);padding:14px;margin-top:18px;font-size:.9rem;line-height:1.65}
.constant-help p{margin:8px 0}.constants-page{max-width:850px;padding-bottom:80px}.constant-content article{border-bottom:1px solid var(--line);padding:12px 0}.constant-content li{margin:12px 0;line-height:1.7}
.nav-search{font:inherit;color:var(--ink);background:none;border:0;padding:10px;min-height:44px;cursor:pointer}
@media print{.calculator-launcher,.learning-dialog{display:none!important}}

.solution-math-lines{display:block;max-width:100%;overflow-x:auto;margin:8px 0}.wtext,.solution-steps>li>div,.reveal-b{line-height:1.85}.solution-math-lines .katex-display{margin:.5em 0}

.zoom-controls .search-launcher{position:static;flex:none;margin-left:4px;box-shadow:none}
.zoom-controls{gap:6px}.zoom-buttons{margin-left:auto}
@media(max-width:360px){.zoom-label{font-size:11px}}
body[data-calculator-position$="right"] .calculator-launcher,body[data-calculator-position$="right"] .calculator-panel{left:auto;right:12px}
body[data-calculator-position^="top"] .calculator-launcher{bottom:auto;top:calc(var(--zoom-top,56px) + 64px)}
body[data-calculator-position^="top"] .calculator-panel{bottom:auto;top:calc(var(--zoom-top,56px) + 116px);max-height:max(40px,calc(var(--zoom-view-height,90vh) - 132px))}@media print{.search-launcher{display:none!important}}

.tool-heading h2{min-width:0;overflow-wrap:anywhere}.tool-close{flex:none}
.learning-dialog{overflow-wrap:anywhere}.learning-dialog input,.learning-dialog select{min-width:0}
body.zoom-small .learning-dialog{padding:10px}
body.zoom-small .calculator-keys{gap:4px}
body.zoom-small .calculator-keys button{padding:4px 0;min-width:0}

.calculator-panel{max-height:max(40px,calc(var(--zoom-view-height,90vh) - var(--tools-bottom,14px) - 64px))}#app{padding-bottom:64px}

/* Settings stay readable and reachable regardless of reading preferences. */
.zoom-controls .search-launcher{margin-left:auto}
.settings-launcher,.settings-action{min-height:44px;padding:8px 12px;border:1px solid var(--line);border-radius:10px;background:var(--surface);color:var(--ink);font:inherit;cursor:pointer}
.settings-panel{zoom:var(--app-zoom-inverse,1);width:480px;max-width:calc(100vw - 24px);max-height:calc(100dvh - 80px)}
.settings-panel .zoom-buttons{display:flex;gap:8px;margin:8px 0}
.settings-field{display:block;margin-top:16px}
.settings-field>span{display:block;font-weight:600}
.settings-panel input[type=checkbox]{width:24px;min-height:24px;height:24px}
.settings-panel input[type=color]{height:48px;padding:4px}
.settings-panel .settings-action{display:block;width:100%;margin-top:12px}
.calculator-launcher[hidden]{display:none!important}
.scientific-keys{margin-top:12px}
.scientific-keys button:last-child{background:var(--surface-2);color:var(--ink)}
#app.custom-reading-size :is(p,li,td,th,.say,.wtext,.rule-b,.tip-b,.q-prompt,.reveal-b){font-size:var(--reading-size);line-height:1.8}
@media print{.settings-launcher{display:none!important}}
#app{color:var(--ink)}

/* Five clear background choices, with compact settings rows. */
.settings-panel{padding:20px;border-radius:20px}
.settings-panel .tool-heading{margin-bottom:8px}
.settings-panel h3{font-size:1rem;margin:18px 0 8px}
.settings-panel .settings-field{margin-top:12px}
.settings-panel .settings-field>span{font-size:.9rem}
.settings-panel input[type=color]{width:72px;height:40px;min-height:40px}
.settings-panel input[type=range]{padding:0;margin:0;accent-color:var(--brand)}
.settings-panel .font-value{font-size:.8rem;color:var(--ink-2)}
.background-palette{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:6px;margin-top:10px}
.background-palette button{display:flex;flex-direction:column;align-items:center;gap:6px;min-width:0;padding:6px 2px;border:2px solid transparent;border-radius:10px;background:transparent;color:var(--ink);font-size:11px;cursor:pointer}
.background-palette button[aria-pressed=true]{border-color:var(--brand);background:var(--surface-2);font-weight:700}
.color-swatch{display:block;width:30px;height:30px;border:1px solid #9aa6b5;border-radius:50%}
.settings-panel .settings-action{font-size:.85rem}
.settings-field:has(input[type=checkbox]){display:flex;align-items:center;justify-content:space-between;gap:12px}
.settings-field:has(input[type=checkbox]) input{flex:none}

.community-page{max-width:760px;padding-top:28px;padding-bottom:80px;overflow-wrap:anywhere}
.community-eyebrow{font-size:.75rem;letter-spacing:.14em;color:var(--brand);margin-top:26px}
.community-page h1{font-size:clamp(1.6rem,5vw,2.3rem);line-height:1.25}
.community-intro{color:var(--ink-2);line-height:1.8}
.community-card{border:1px solid var(--line);border-radius:16px;padding:20px;margin:20px 0;background:var(--surface)}
.community-card h2{font-size:1.1rem;margin:0 0 12px}
.community-card p,.community-card li{line-height:1.8}
.community-note{color:var(--ink-2);font-size:.9rem}
.community-links{display:flex;flex-wrap:wrap;gap:8px 20px}
.community-links a{display:inline-flex;align-items:center;min-height:44px;color:var(--ink)}

.donation-number{font-size:clamp(1rem,4.5vw,1.6rem);font-weight:700;font-variant-numeric:tabular-nums;user-select:all}
.community-contact{display:flex;flex-direction:column;gap:4px;padding:14px 0;border-bottom:1px solid var(--line);color:var(--ink);text-decoration:none;min-height:44px}
.community-contact span{color:var(--brand);text-decoration:underline;overflow-wrap:anywhere}

.academy-mark{display:block;object-fit:contain;border-radius:8px}
.brand-text small img{vertical-align:middle}
.academy-intro{display:flex;align-items:center;gap:28px;padding-top:24px;padding-bottom:16px}
.academy-logo{width:220px;height:auto;max-width:100%;border-radius:18px;flex:none}
.academy-intro p{line-height:1.75}.academy-intro h2{font-size:1.6rem;margin:8px 0}
.math-subject{display:flex;align-items:center;gap:12px;margin-top:16px}
.release-note-wrap{padding-bottom:24px}
.release-note{padding:18px;border:1px solid var(--line);border-radius:14px;background:var(--surface);margin:22px 0;line-height:1.75}
.release-note p{margin:8px 0}.release-note a{color:var(--brand)}
.zoom-controls .community-shortcut{display:grid;place-items:center;flex:none;width:44px;height:44px;border:1px solid;border-radius:12px;text-decoration:none}
.community-shortcut[data-ui-icon]::before{margin:0;width:24px;height:24px}
.community-shortcut[data-ui-icon=support]{color:#b52b60;background:#fff0f5;border-color:#f5c8d8}
.community-shortcut[data-ui-icon=contact]{color:#076a9d;background:#eaf7ff;border-color:#bce4f7}
.community-links [data-ui-icon=support]::before,.header-more [data-ui-icon=support]::before{background:#d13c78}
.community-links [data-ui-icon=contact]::before,.header-more [data-ui-icon=contact]::before{background:#1284bd}
.community-contact[data-ui-icon=telegram]::before{background:#1395cc}
.community-contact[data-ui-icon=instagram]::before{background:linear-gradient(35deg,#f6b73b,#e13c80,#7954cd)}
.community-contact[data-ui-icon=email]::before{background:#1c9a75}
@media(max-width:600px){.academy-intro{flex-direction:column;gap:12px}.academy-logo{width:210px}.academy-intro h2{font-size:1.35rem}}
body.zoom-narrow .academy-intro{flex-direction:column;gap:12px}
@media print{.community-shortcut{display:none!important}}

.academy-subjects h2{font-size:1.15rem;line-height:1.4}.academy-subjects ul{padding-inline-start:22px}.academy-subjects a{color:var(--brand);display:inline-block;min-height:44px;line-height:1.6;padding:10px 0;box-sizing:border-box}

/* A clear subject name and one collapsible navigation panel. */
.topbar .topbar-in{flex-wrap:wrap;justify-content:space-between;gap:12px}
.brand-text .brand-academy{font-size:13px;line-height:1.5;color:var(--ink-2)}
.brand-text .brand-subject{display:block;font:800 28px/1.2 var(--font);color:var(--ink)}
.menu-toggle{display:flex;align-items:center;gap:7px;min-height:44px;padding:8px 12px;cursor:pointer;border:1px solid var(--line);border-radius:10px;background:var(--surface);color:var(--ink);font:600 14px var(--font);flex:none}
.menu-toggle svg{display:block}.menu-chevron{transition:transform .15s}.menu-toggle[aria-expanded=true] .menu-chevron{transform:rotate(180deg)}
.main-menu{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:6px;flex-basis:100%;width:100%;padding-top:10px;border-top:1px solid var(--line)}
.main-menu[hidden]{display:none!important}
.main-menu a{padding:12px;border-radius:8px;color:var(--ink);text-decoration:none;min-height:44px;overflow-wrap:anywhere}
.main-menu a:hover,.main-menu a:focus-visible{background:var(--brand-l)}
.main-menu .topstats{grid-column:1/-1;margin:4px 0}
.home-menu{padding-top:24px;padding-bottom:24px}
.home-menu h2{font-size:1.2rem;margin-bottom:14px}
.home-menu-links{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}
.home-menu-links a{justify-content:flex-start;text-align:left;white-space:normal;overflow-wrap:anywhere}
.home-menu-links [data-ui-icon=support]::before,.main-menu [data-ui-icon=support]::before{background:#d13c78}
.home-menu-links [data-ui-icon=contact]::before,.main-menu [data-ui-icon=contact]::before{background:#1284bd}
body.zoom-narrow .main-menu,body.zoom-narrow .home-menu-links{grid-template-columns:repeat(2,minmax(0,1fr))}
body.zoom-small .brand .academy-mark{width:40px;height:34px}
body.zoom-small .brand{gap:6px}
body.zoom-small .brand-text .brand-subject{font-size:18px}
body.zoom-small .brand-text .brand-academy{font-size:11px}
body.zoom-small .main-menu,body.zoom-small .home-menu-links{grid-template-columns:minmax(0,1fr)}
@media print{.menu-toggle,.main-menu{display:none!important}}

.main-menu{max-height:max(44px,calc(var(--zoom-view-height,80vh) - 145px));overflow-y:auto;overscroll-behavior:contain}