@layer theme{:root,:host{--font-sans:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue","Noto Sans",Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";--font-mono:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;--default-font-family:var(--font-sans);--default-mono-font-family:var(--font-mono)}}@layer base{*,:after,:before,::backdrop{box-sizing:border-box;border:0 solid;margin:0;padding:0}::file-selector-button{box-sizing:border-box;border:0 solid;margin:0;padding:0}html,:host{-webkit-text-size-adjust:100%;tab-size:4;line-height:1.5;font-family:var(--default-font-family,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue","Noto Sans",Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji");font-feature-settings:var(--default-font-feature-settings,normal);font-variation-settings:var(--default-font-variation-settings,normal);-webkit-tap-highlight-color:transparent}hr{height:0;color:inherit;border-top-width:1px}abbr:where([title]){-webkit-text-decoration:underline dotted;text-decoration:underline dotted}h1,h2,h3,h4,h5,h6{font-size:inherit;font-weight:inherit}a{color:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;text-decoration:inherit}b,strong{font-weight:bolder}code,kbd,samp,pre{font-family:var(--default-mono-font-family,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace);font-feature-settings:var(--default-mono-font-feature-settings,normal);font-variation-settings:var(--default-mono-font-variation-settings,normal);font-size:1em}small{font-size:80%}sub,sup{vertical-align:baseline;font-size:75%;line-height:0;position:relative}sub{bottom:-.25em}sup{top:-.5em}table{text-indent:0;border-color:inherit;border-collapse:collapse}:-moz-focusring:where(:not(iframe)){outline:auto}progress{vertical-align:baseline}summary{display:list-item}ol,ul,menu{list-style:none}img,svg,video,canvas,audio,iframe,embed,object{vertical-align:middle;display:block}img,video{max-width:100%;height:auto}button,input,select,optgroup,textarea{font:inherit;font-feature-settings:inherit;font-variation-settings:inherit;letter-spacing:inherit;color:inherit;opacity:1;background-color:#0000;border-radius:0}::file-selector-button{font:inherit;font-feature-settings:inherit;font-variation-settings:inherit;letter-spacing:inherit;color:inherit;opacity:1;background-color:#0000;border-radius:0}:where(select:is([multiple],[size])) optgroup{font-weight:bolder}:where(select:is([multiple],[size])) optgroup option{padding-inline-start:20px}::file-selector-button{margin-inline-end:4px}::placeholder{opacity:1}@supports (not ((-webkit-appearance:-apple-pay-button))) or (contain-intrinsic-size:1px){::placeholder{color:currentColor}@supports (color:color-mix(in lab, red, red)){::placeholder{color:color-mix(in oklab,currentcolor 50%,transparent)}}}textarea{resize:vertical}::-webkit-search-decoration{-webkit-appearance:none}::-webkit-date-and-time-value{min-height:1lh;text-align:inherit}::-webkit-datetime-edit{display:inline-flex}::-webkit-datetime-edit-fields-wrapper{padding:0}::-webkit-datetime-edit{padding-block:0}::-webkit-datetime-edit-year-field{padding-block:0}::-webkit-datetime-edit-month-field{padding-block:0}::-webkit-datetime-edit-day-field{padding-block:0}::-webkit-datetime-edit-hour-field{padding-block:0}::-webkit-datetime-edit-minute-field{padding-block:0}::-webkit-datetime-edit-second-field{padding-block:0}::-webkit-datetime-edit-millisecond-field{padding-block:0}::-webkit-datetime-edit-meridiem-field{padding-block:0}::-webkit-calendar-picker-indicator{line-height:1}:-moz-ui-invalid{box-shadow:none}button,input:where([type=button],[type=reset],[type=submit]){appearance:button}::file-selector-button{appearance:button}::-webkit-inner-spin-button{height:auto}::-webkit-outer-spin-button{height:auto}[hidden]:where(:not([hidden=until-found])){display:none!important}}@layer components;@layer utilities{.visible{visibility:visible}.grid{display:grid}}:root{--math-ink:#18243a;--math-blue:#2454a5;--math-red:#cc5548;--math-paper:#f4f1e8;--math-sheet:#fffdf7;--math-grid:#d8e0eb;--math-muted:#697386;--math-line:#cbd2dc;--math-yellow:#f0df8a}*{box-sizing:border-box}html{background:var(--math-paper)}body{color:var(--math-ink);background:var(--math-paper);margin:0;font-family:Georgia,Times New Roman,serif}button,a{font:inherit}button{cursor:pointer}a{color:inherit;text-decoration:none}button:disabled{cursor:not-allowed}button:focus-visible,a:focus-visible{outline:3px solid var(--math-red);outline-offset:3px}::selection{background:var(--math-yellow);color:var(--math-ink)}.math-page{background-color:var(--math-paper);min-height:100vh;padding:22px 20px 32px}.math-shell{width:min(1210px,100%);margin:auto}.math-header,.math-brand,.math-label,.sheet-rule,.proof-actions,.math-footer{align-items:center;display:flex}.math-header{border-bottom:1px solid var(--math-ink);background:var(--math-paper);min-height:49px;color:var(--math-muted);letter-spacing:.11em;text-transform:uppercase;justify-content:space-between;gap:18px;padding:0 3px;font:10px Courier New,monospace}.math-brand{color:var(--math-ink);gap:10px;font-weight:700}.math-mark{border:1px solid var(--math-blue);width:31px;height:31px;color:var(--math-blue);place-items:center;font:20px Georgia,serif;display:grid}.math-status{color:var(--math-red)}.math-hero{border-bottom:2px solid var(--math-ink);background:var(--math-paper);grid-template-columns:minmax(0,1fr) 250px;align-items:end;gap:40px;padding:91px 3px 75px;display:grid}.math-hero h1{letter-spacing:-.1em;margin:0;font:400 clamp(4.2rem,9vw,8.5rem)/.78 Georgia,serif}.math-hero h1 em{color:var(--math-blue);font-style:italic}.math-hero p{max-width:550px;color:var(--math-muted);margin:29px 0 0;font-size:17px;line-height:1.6}.math-equation{border-top:2px solid var(--math-red);border-bottom:1px solid var(--math-red);color:var(--math-red);gap:13px;padding:16px 0;display:grid}.math-equation span,.math-equation small{letter-spacing:.1em;text-transform:uppercase;font:10px Courier New,monospace}.math-equation strong{color:var(--math-ink);letter-spacing:-.08em;font:italic 39px Georgia,serif}.math-equation small{color:var(--math-muted);text-transform:none}.math-workbench{grid-template-columns:245px minmax(0,1fr);gap:32px;padding:41px 3px 70px;display:grid}.math-label{border-bottom:2px solid var(--math-ink);color:var(--math-blue);letter-spacing:.12em;text-transform:uppercase;justify-content:space-between;gap:12px;padding-bottom:12px;font:10px Courier New,monospace}.math-label span:last-child{color:var(--math-muted)}.problem-index>p{color:var(--math-muted);margin:17px 0 20px;font-size:14px;line-height:1.45}.problem-list{border-top:1px solid var(--math-line)}.problem-row{border:0;border-bottom:1px solid var(--math-line);width:100%;min-height:79px;color:var(--math-ink);text-align:left;background:0 0;grid-template-columns:29px minmax(0,1fr);gap:8px;padding:13px 7px;display:grid}.problem-row:hover,.problem-row.is-active{background:#e6edf8}.problem-row>span{color:var(--math-red);font:11px Courier New,monospace}.problem-row strong,.problem-row small{grid-column:2}.problem-row strong{font-size:18px;font-weight:400}.problem-row small{color:var(--math-muted);margin-top:3px;font:10px/1.4 Courier New,monospace}.margin-note{background:var(--math-yellow);margin-top:52px;padding:16px 14px;transform:rotate(-1.5deg)}.margin-note span{color:var(--math-red);letter-spacing:.12em;font:10px Courier New,monospace}.margin-note p{margin:10px 0 0;font-size:14px;line-height:1.45}.proof-sheet{background:var(--math-sheet);min-width:0;padding:24px 28px 27px;box-shadow:0 16px 38px #1b2a4421}.sheet-rule{border-bottom:1px solid var(--math-line);color:var(--math-muted);letter-spacing:.11em;justify-content:space-between;gap:18px;padding-bottom:17px;font:10px Courier New,monospace}.sheet-rule span:first-child{color:var(--math-blue)}.problem-question{padding:31px 0 24px}.problem-question>span,.givens>span{color:var(--math-blue);letter-spacing:.12em;font:10px Courier New,monospace}.problem-question h2{letter-spacing:-.07em;max-width:690px;margin:12px 0 0;font-size:clamp(2.2rem,5vw,4.5rem);font-weight:400;line-height:.95}.visual-proof{border-top:1px solid var(--math-line);border-bottom:1px solid var(--math-line);grid-template-columns:minmax(230px,1fr) 160px;gap:25px;padding:21px 0 24px;display:grid}.diagram-frame{border:1px solid var(--math-blue);background:repeating-linear-gradient(0deg,#0000 0 23px,#dfe7f1 24px),repeating-linear-gradient(90deg,#0000 0 23px,#dfe7f1 24px);min-height:148px;position:relative;overflow:hidden}.diagram-frame:before,.diagram-frame:after{content:"";background:var(--math-blue);position:absolute}.diagram-frame:before{height:1px;bottom:27%;left:15%;right:10%}.diagram-frame:after{width:1px;top:15%;bottom:16%;left:27%}.diagram-glyph{z-index:1;color:var(--math-red);font:italic 39px Georgia,serif;position:absolute;top:39%;left:45%;transform:rotate(-9deg)}.diagram-label{z-index:1;color:var(--math-blue);text-transform:uppercase;font:10px Courier New,monospace;position:absolute}.diagram-label-a{bottom:17%;left:13%}.diagram-label-b{top:18%;right:10%}.givens{align-content:start;gap:10px;display:grid}.givens strong{border-bottom:1px solid var(--math-line);color:var(--math-ink);padding-bottom:9px;font:400 15px Courier New,monospace}.step-stack{padding-top:8px}.proof-step{border-bottom:1px solid var(--math-line);grid-template-columns:42px minmax(0,1fr) 20px;gap:15px;min-height:73px;padding:17px 0;display:grid}.step-number{color:var(--math-red);font:11px Courier New,monospace}.proof-step h3{margin:0;font-size:18px;font-weight:400}.proof-step p{max-width:620px;color:var(--math-muted);margin:7px 0 0;font-size:15px;line-height:1.5}.step-closed{color:#9aa2ae;margin-top:7px;font:11px Courier New,monospace;display:block}.step-check{color:var(--math-blue);font:18px Courier New,monospace}.proof-step:not(.is-open) h3{color:#8b94a2}.proof-actions{gap:20px;margin-top:21px}.math-primary{border:1px solid var(--math-blue);background:var(--math-blue);color:#fff;text-transform:uppercase;padding:13px 17px;font:11px Courier New,monospace}.math-primary:disabled{background:var(--math-ink);border-color:var(--math-ink)}.math-reset{color:var(--math-muted);text-underline-offset:4px;background:0 0;border:0;padding:0;font:11px Courier New,monospace;text-decoration:underline}.math-footer{border-top:1px solid var(--math-ink);background:var(--math-paper);color:var(--math-muted);letter-spacing:.1em;justify-content:space-between;gap:15px;padding:18px 3px 0;font:10px Courier New,monospace}@media (max-width:760px){.math-page{padding-inline:14px}.math-header>span:nth-child(2){display:none}.math-hero{padding:70px 3px 58px;display:block}.math-hero h1{font-size:clamp(4rem,18vw,6rem)}.math-equation{width:210px;margin:48px 0 0 auto}.math-workbench{padding-top:32px;display:block}.problem-index{margin-bottom:35px}.margin-note{max-width:310px}.proof-sheet{padding:20px 16px 23px}.sheet-rule{flex-direction:column;align-items:start;gap:8px}.problem-question h2{font-size:clamp(2.6rem,11vw,4rem)}.visual-proof{grid-template-columns:1fr}.diagram-frame{min-height:128px}.math-footer{gap:8px;display:grid}}