:root {
--c-bg: #f7f7f5;
--c-surface: #ffffff;
--c-surface-2: #f1f2f4;
--c-field: #ffffff;
--c-text: #1b1f24;
--c-muted: #5b6470;
--c-border: #dfe3e8;
--c-border-strong: #b8c0cb;
--c-primary: #2456d6;
--c-primary-hover: #1b45b3;
--c-on-primary: #ffffff;
--c-primary-soft: #e8eefc;
--c-accent: #2456d6;
--c-on-accent: #ffffff;
--c-link: var(--c-primary);
--c-focus: #1a73e8;
--c-success: #1a7f4b;
--c-success-bg: #e5f5ec;
--c-danger: #b3261e;
--c-danger-bg: #fdecea;
--c-warn: #8a5a00;
--c-warn-bg: #fff4d6;
--c-info: #1d5fa8;
--c-info-bg: #e7f1fc;
--c-ink: #1b1f24;
--c-on-ink: #ffffff;
--font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
--font-display: var(--font-sans);
--font-mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
--font-num: var(--font-sans);
--radius: 8px;
--radius-lg: 14px;
--shadow: 0 1px 2px rgb(16 24 40 / 0.06), 0 1px 3px rgb(16 24 40 / 0.08);
--shadow-lg: 0 12px 32px rgb(16 24 40 / 0.14);
--w-page: 72rem;
--w-prose: 46rem;
--gap: clamp(1rem, 2.5vw, 1.5rem);
--h1-weight: 750;
--h1-tracking: -0.02em;
--fs-2xs: 0.75rem;
--fs-xs: 0.8125rem;
--fs-sm: 0.875rem;
--fs-md: 1rem;
--fs-body: 1.0625rem;
--fs-lead: 1.125rem;
--fs-lg: 1.25rem;
--fs-xl: 1.5rem;
--fs-2xl: 2rem;
--fs-h1: clamp(1.875rem, 1.35rem + 2vw, 2.5rem);
--fs-hero: clamp(2.125rem, 1.35rem + 3.4vw, 3.5rem);
--fs-answer: clamp(2.25rem, 1.6rem + 3vw, 3.25rem);
--h1-size: var(--fs-h1);
--fw-medium: 550;
--fw-strong: 650;
--fw-bold: var(--h1-weight);
--btn-height: 2.75rem;
--btn-pad: 0.55rem 1.1rem;
--btn-size: var(--fs-md);
--btn-weight: var(--fw-strong);
--btn-radius: var(--radius);
--ease-out: cubic-bezier(0.23, 1, 0.32, 1);
--ease-in-out: cubic-bezier(0.77, 0, 0.175, 1);
}
*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-padding-top: 1rem; }
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
::selection { background: var(--c-primary-soft); color: var(--c-text); }
input, textarea, [contenteditable] { caret-color: var(--c-primary); }
html { scrollbar-color: var(--c-border-strong) transparent; }
button, summary { -webkit-tap-highlight-color: transparent; }
body {
margin: 0;
font-family: var(--font-sans);
font-size: var(--fs-body);
line-height: 1.6;
color: var(--c-text);
background: var(--c-bg);
-webkit-font-smoothing: antialiased;
}
img, svg, canvas, video { max-width: 100%; }
a { color: var(--c-link); text-underline-offset: 0.15em; }
:focus-visible { outline: 3px solid var(--c-focus); outline-offset: 2px; border-radius: 4px; }
h1, h2, h3, h4 { font-family: var(--font-display); font-weight: var(--h1-weight); line-height: 1.2; color: var(--c-text); text-wrap: balance; }
h1 { font-size: var(--fs-h1); letter-spacing: var(--h1-tracking); margin: 0 0 0.5rem; }
h2 { font-size: var(--fs-xl); margin: 2.25rem 0 0.75rem; }
h3 { font-size: var(--fs-lead); margin: 1.5rem 0 0.5rem; }
p, ul, ol, table, pre, blockquote { margin: 0 0 1rem; }
code, kbd, pre, samp { font-family: var(--font-mono); font-size: 0.92em; }
kbd { border: 1px solid var(--c-border-strong); border-bottom-width: 2px; border-radius: 5px; padding: 0 0.35em; background: var(--c-surface); }
hr { border: 0; border-top: 1px solid var(--c-border); margin: 2rem 0; }
.k-sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.k-muted { color: var(--c-muted); }
.k-num { font-family: var(--font-num); font-variant-numeric: tabular-nums; }
.k-skip { position: absolute; left: 0.5rem; top: -4rem; z-index: 100; background: var(--c-ink); color: var(--c-on-ink); padding: 0.6rem 1rem; border-radius: var(--radius); }
.k-skip:focus { top: 0.5rem; }
.k-header { background: var(--c-header-bg, var(--c-surface)); color: var(--c-header-text, var(--c-text)); border-bottom: 1px solid var(--c-header-border, var(--c-border)); }
.k-header__inner { max-width: var(--w-page); margin: 0 auto; padding: 0.6rem var(--gap); display: flex; align-items: center; gap: 0.75rem 1.25rem; flex-wrap: wrap; }
.k-brand { display: inline-flex; align-items: center; gap: 0.5rem; font-family: var(--font-display); font-weight: 800; font-size: var(--fs-lg); letter-spacing: -0.01em; color: inherit; text-decoration: none; min-height: 2.75rem; }
.k-brand__mark { display: inline-grid; place-items: center; width: 1.9rem; height: 1.9rem; border-radius: 8px; background: var(--c-primary); color: var(--c-on-primary); font-size: var(--fs-md); }
.k-brand__mark svg { width: 1.15rem; height: 1.15rem; }
.k-brand__logo { display: inline-flex; flex: none; width: 2.1rem; height: 2.1rem; }
.k-brand__logo svg { display: block; width: 100%; height: 100%; }
.k-brand__name { white-space: nowrap; }
.k-nav { flex: 1 1 auto; min-width: 0; }
.k-nav ul { display: flex; gap: 0.15rem; list-style: none; margin: 0; padding: 0; }
.k-nav a { display: block; padding: 0.5rem 0.7rem; border-radius: var(--radius); color: inherit; text-decoration: none; font-weight: var(--fw-medium); font-size: var(--fs-md); white-space: nowrap; transition: background-color 150ms ease, color 150ms ease; }
.k-nav a[aria-current] { color: var(--c-nav-current, var(--c-primary)); box-shadow: inset 0 -2px 0 currentColor; border-radius: var(--radius) var(--radius) 0 0; }
.k-header__actions { display: flex; align-items: center; gap: 0.4rem; margin-left: auto; }
.k-search-btn, .k-icon-btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; min-width: 2.75rem; min-height: 2.75rem; padding: 0 0.8rem; font: inherit; font-size: var(--fs-sm); line-height: 1.25; color: var(--c-muted); background: var(--c-field); border: 1px solid var(--c-border-strong); border-radius: var(--btn-radius); cursor: pointer; }
.k-search-btn kbd { font-size: var(--fs-2xs); }
@media (max-width: 52rem) {
.k-header__inner { padding-bottom: 0; }
.k-nav { order: 3; flex-basis: 100%; margin: 0 calc(var(--gap) * -1); overflow-x: auto; scrollbar-width: none; -webkit-overflow-scrolling: touch; }
.k-nav::-webkit-scrollbar { display: none; }
.k-nav ul { padding: 0 var(--gap); }
.k-nav a { padding: 0.55rem 0.6rem; font-size: var(--fs-sm); }
.k-search-btn span { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.k-search-btn kbd { display: none; }
.k-search-btn, .k-icon-btn { padding: 0; width: 2.75rem; }
}
.k-search { width: min(40rem, calc(100vw - 2rem)); max-height: min(34rem, 85vh); margin-top: 8vh; padding: 0; border: 1px solid var(--c-border); border-radius: var(--radius-lg); background: var(--c-surface); color: var(--c-text); box-shadow: var(--shadow-lg); overflow: hidden; }
.k-search[open] { display: flex; flex-direction: column; }
.k-search::backdrop { background: rgb(15 20 30 / 0.45); }
.k-search__box { display: flex; gap: 0.5rem; padding: 0.75rem; border-bottom: 1px solid var(--c-border); }
.k-search__box input { flex: 1; min-width: 0; min-height: 2.75rem; padding: 0 0.75rem; font: inherit; font-size: var(--fs-body); color: var(--c-text); background: var(--c-field); border: 1px solid var(--c-border-strong); border-radius: var(--radius); }
.k-search__results { list-style: none; margin: 0; padding: 0.4rem; overflow-y: auto; }
.k-search__results a { display: flex; justify-content: space-between; gap: 1rem; padding: 0.6rem 0.75rem; border-radius: var(--radius); color: var(--c-text); text-decoration: none; }
.k-search__results a span:last-child { color: var(--c-muted); font-size: var(--fs-sm); white-space: nowrap; }
.k-search__results [aria-selected="true"] a { background: var(--c-primary-soft); }
.k-search__empty { padding: 1rem; color: var(--c-muted); }
.k-search__hint { margin: 0; padding: 0.6rem 1rem; border-top: 1px solid var(--c-border); font-size: var(--fs-sm); }
.k-main { max-width: var(--w-page); margin: 0 auto; padding: clamp(1rem, 3vw, 2rem) var(--gap) 3rem; }
.k-page--tool, .k-page--guide, .k-page--plain { max-width: var(--w-prose); margin: 0 auto; }
.k-page--wide { max-width: none; }
.k-page__head { margin-bottom: 1rem; }
.k-crumbs ol { display: flex; flex-wrap: wrap; gap: 0.25rem 0.5rem; list-style: none; margin: 0 0 0.6rem; padding: 0; font-size: var(--fs-sm); color: var(--c-muted); }
.k-crumbs li + li::before { content: "›"; margin-right: 0.5rem; }
.k-crumbs a { color: inherit; }
.k-lede { font-size: var(--fs-lead); color: var(--c-muted); margin: 0 0 0.75rem; max-width: 40rem; }
.k-trust { display: flex; flex-wrap: wrap; gap: 0.2rem 0.5rem; margin: 0 0 0.25rem; font-size: var(--fs-sm); color: var(--c-muted); }
.k-trust span + span::before { content: "·"; margin-right: 0.5rem; }
.k-trust a { color: inherit; }
.k-prose, .k-page__head, .k-faq, .k-sources { overflow-wrap: break-word; }
.k-prose code, .k-prose samp, .k-prose kbd, .k-faq code, .k-faq samp { overflow-wrap: anywhere; }
.k-prose > :first-child { margin-top: 0; }
.k-prose ul, .k-prose ol { padding-left: 1.3rem; }
.k-prose li { margin-bottom: 0.3rem; }
.k-prose table, .k-table { width: 100%; border-collapse: collapse; font-size: var(--fs-md); font-variant-numeric: tabular-nums; }
.k-prose th, .k-prose td, .k-table th, .k-table td { padding: 0.55rem 0.7rem; border-bottom: 1px solid var(--c-border); text-align: left; vertical-align: top; }
.k-prose thead th, .k-table thead th { font-size: var(--fs-sm); text-transform: uppercase; letter-spacing: 0.04em; color: var(--c-muted); border-bottom: 2px solid var(--c-border-strong); }
.k-table td.k-num, .k-table th.k-num { text-align: right; }
.k-table-wrap { overflow-x: auto; margin: 0 0 1rem; }
@media (max-width: 40rem) {
.k-prose > table { display: block; max-width: 100%; overflow-x: auto; }
}
.k-table-wrap > table { margin: 0; }
.k-prose blockquote { margin-left: 0; padding: 0.25rem 0 0.25rem 1rem; border-left: 3px solid var(--c-primary); color: var(--c-muted); }
.k-prose pre { overflow-x: auto; padding: 0.9rem 1rem; background: var(--c-surface-2); border-radius: var(--radius); }
.k-formula { margin: 0 0 1rem; padding: 0.9rem 1.1rem; background: var(--c-surface-2); border-radius: var(--radius); font-family: var(--font-mono); font-size: var(--fs-md); overflow-x: auto; }
.k-callout { margin: 0 0 1rem; padding: 0.85rem 1rem; border-radius: var(--radius); background: var(--c-info-bg); }
.k-callout--warn { background: var(--c-warn-bg); }
.k-callout--ok { background: var(--c-success-bg); }
.k-callout > :last-child { margin-bottom: 0; }
.tool { margin: 1rem 0 2rem; padding: clamp(1rem, 3vw, 1.6rem); background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius-lg); }
.tool > :first-child { margin-top: 0; }
.tool > :last-child { margin-bottom: 0; }
.tool h2, .tool h3 { margin-top: 1.25rem; font-size: var(--fs-lead); }
.tool label { font-weight: var(--fw-strong); }
.tool input:not([type="checkbox"]):not([type="radio"]):not([type="range"]):not([type="color"]):not([type="file"]),
.tool select, .tool textarea, .k-input {
max-width: 100%; min-height: 2.75rem; padding: 0.55rem 0.75rem;
font: inherit; color: var(--c-text); background: var(--c-field);
border: 1px solid var(--c-border-strong); border-radius: var(--radius);
}
.tool textarea { width: 100%; min-height: 7rem; line-height: 1.5; }
.tool div:not([class]) > label:not([class]):not(:has(input)) { display: block; margin: 0 0 0.3rem; }
.tool div:not([class]) > label:not([class]) + input:not([type="checkbox"]):not([type="radio"]):not([type="range"]):not([type="color"]):not([type="file"]):not([style*="width"]),
.tool div:not([class]) > label:not([class]) + select:not([style*="width"]),
.tool div:not([class]) > label:not([class]) + br + input:not([type="checkbox"]):not([type="radio"]):not([type="range"]):not([type="color"]):not([type="file"]):not([style*="width"]),
.tool div:not([class]) > label:not([class]) + br + select:not([style*="width"]) { width: min(100%, 22rem); }
.tool > div:not([class]) > div:not([class]), .tool > div:not([class]):not(:last-child) { margin-bottom: 0.75rem; }
.tool div:not([class]) > button + button { margin-left: 0.25rem; }
.tool input:focus-visible, .tool select:focus-visible, .tool textarea:focus-visible, .k-input:focus-visible { outline: 3px solid var(--c-focus); outline-offset: 1px; border-color: var(--c-primary); }
.tool input[type="checkbox"], .tool input[type="radio"] { width: 1.15rem; height: 1.15rem; accent-color: var(--c-primary); vertical-align: -0.15em; }
.tool input[type="range"] { accent-color: var(--c-primary); }
.tool button, .k-btn {
display: inline-flex; align-items: center; justify-content: center; gap: 0.4rem;
min-height: var(--btn-height); padding: var(--btn-pad);
font: inherit; font-size: var(--btn-size); font-weight: var(--btn-weight); line-height: 1.25; color: var(--c-on-primary); background: var(--c-primary);
border: 1px solid transparent; border-radius: var(--btn-radius); cursor: pointer; text-decoration: none;
transition: transform 120ms var(--ease-out), background-color 150ms ease, border-color 150ms ease, color 150ms ease;
}
.tool button:disabled, .k-btn:disabled { opacity: 0.55; cursor: not-allowed; }
.k-btn--ghost, .tool button.k-btn--ghost, .tool button[type="reset"] { color: var(--c-text); background: transparent; border-color: var(--c-border-strong); }
.tool table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
.tool td, .tool th { padding: 0.45rem 0.5rem; border-bottom: 1px solid var(--c-border); text-align: left; }
.tool [aria-live], .tool output { font-variant-numeric: tabular-nums; }
.k-form { display: grid; gap: 0.9rem 1rem; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr)); }
.k-field { display: flex; flex-direction: column; gap: 0.3rem; min-width: 0; }
.k-field > label, .k-field > .k-label { font-weight: var(--fw-strong); font-size: var(--fs-md); }
.k-field > input, .k-field > select, .k-field > textarea { width: 100%; }
.k-field__hint { font-size: var(--fs-sm); color: var(--c-muted); }
.k-field--wide { grid-column: 1 / -1; }
.k-affix { display: flex; align-items: stretch; }
.k-affix > span { display: grid; place-items: center; padding: 0 0.7rem; background: var(--c-surface-2); border: 1px solid var(--c-border-strong); color: var(--c-muted); font-variant-numeric: tabular-nums; }
.k-affix > span:first-child { border-right: 0; border-radius: var(--radius) 0 0 var(--radius); }
.k-affix > span:last-child { border-left: 0; border-radius: 0 var(--radius) var(--radius) 0; }
.k-affix > input { flex: 1; min-width: 0; width: 100%; }
.k-affix > span:first-child + input { border-top-left-radius: 0 !important; border-bottom-left-radius: 0 !important; }
.k-affix > input:not(:last-child) { border-top-right-radius: 0 !important; border-bottom-right-radius: 0 !important; }
.k-check { display: flex; align-items: flex-start; gap: 0.55rem; font-weight: var(--fw-medium); }
.k-check input { margin-top: 0.25em; flex: none; }
.k-segmented { display: inline-flex; padding: 3px; background: var(--c-surface-2); border-radius: calc(var(--radius) + 3px); }
.k-segmented label { position: relative; }
.k-segmented input { position: absolute; opacity: 0; inset: 0; width: 100%; height: 100%; margin: 0; cursor: pointer; }
.k-segmented span { display: block; padding: 0.4rem 0.9rem; border-radius: var(--radius); font-weight: var(--fw-strong); font-size: var(--fs-md); color: var(--c-muted); }
.k-segmented input:checked + span { background: var(--c-surface); color: var(--c-text); box-shadow: var(--shadow); }
.k-segmented input:focus-visible + span { outline: 3px solid var(--c-focus); outline-offset: 1px; }
.k-result { margin-top: 1.25rem; padding: 1rem 1.15rem; background: var(--c-result-bg, var(--c-primary-soft)); border-radius: var(--radius); }
.k-result__label { margin: 0; font-size: var(--fs-sm); font-weight: var(--fw-strong); color: var(--c-muted); }
.k-result__value { margin: 0; font-family: var(--font-num); font-size: var(--fs-answer); font-weight: var(--fw-bold); line-height: 1.1; font-variant-numeric: tabular-nums; color: var(--c-result-text, var(--c-text)); }
.k-result__note { margin: 0.35rem 0 0; color: var(--c-muted); }
.k-badge { display: inline-flex; align-items: center; gap: 0.35rem; padding: 0.2rem 0.65rem; border-radius: 999px; font-size: var(--fs-sm); font-weight: var(--fw-strong); background: var(--c-surface-2); color: var(--c-text); }
.k-badge--ok { background: var(--c-success-bg); color: var(--c-success); }
.k-badge--bad { background: var(--c-danger-bg); color: var(--c-danger); }
.k-badge--warn { background: var(--c-warn-bg); color: var(--c-warn); }
.k-chip { display: inline-flex; align-items: center; padding: 0.25rem 0.7rem; border-radius: 999px; font-size: var(--fs-sm); font-weight: var(--fw-strong); background: var(--c-surface-2); color: var(--c-text); text-decoration: none; }
.k-actions { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 1rem; }
.k-steps { list-style: none; counter-reset: step; margin: 0 0 1rem; padding: 0; }
.k-steps > li { counter-increment: step; position: relative; padding: 0.15rem 0 0.9rem 2.6rem; }
.k-steps > li::before { content: counter(step); position: absolute; left: 0; top: 0; display: grid; place-items: center; width: 1.8rem; height: 1.8rem; border-radius: 50%; background: var(--c-primary); color: var(--c-on-primary); font-weight: var(--fw-bold); font-size: var(--fs-sm); }
.k-steps > li:not(:last-child)::after { content: ""; position: absolute; left: 0.9rem; top: 2rem; bottom: 0.1rem; width: 2px; margin-left: -1px; background: var(--c-border); }
.k-steps mark { background: var(--c-mark, var(--c-warn-bg)); color: inherit; padding: 0 0.2em; border-radius: 3px; }
.k-grid { display: grid; gap: 0 1.75rem; grid-template-columns: repeat(auto-fill, minmax(min(100%, 16rem), 1fr)); list-style: none; margin: 0 0 1rem; padding: 0; }
.k-grid > li { margin: 0; border-top: 1px solid var(--c-border); }
.k-card { display: flex; flex-direction: column; gap: 0.1rem; height: 100%; padding: 0.7rem 0 0.8rem; color: var(--c-text); text-decoration: none; }
.k-card__title { font-weight: var(--fw-strong); color: var(--c-link); }
.k-card__text { font-size: var(--fs-sm); color: var(--c-muted); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.k-tiles { display: grid; gap: 0 1.75rem; grid-template-columns: repeat(auto-fill, minmax(min(100%, 16rem), 1fr)); list-style: none; margin: 0 0 1rem; padding: 0; }
.k-tiles > li { margin: 0; border-top: 1px solid var(--c-border); }
.k-tile { display: flex; flex-direction: column; gap: 0.15rem; height: 100%; padding: 0.75rem 0 0.9rem; color: var(--c-text); text-decoration: none; }
.k-tile__title { font-family: var(--font-display); font-size: var(--fs-lead); font-weight: var(--fw-bold); color: var(--c-link); }
.k-tile__text { font-size: var(--fs-sm); color: var(--c-muted); }
.k-index { display: grid; gap: 1.75rem 2rem; grid-template-columns: repeat(auto-fill, minmax(min(100%, 15rem), 1fr)); list-style: none; margin: 0 0 1rem; padding: 0; }
.k-index > li { margin: 0; padding-top: 0.7rem; border-top: 1px solid var(--c-border-strong); }
.k-index h3 { margin: 0 0 0.4rem; font-size: var(--fs-body); }
.k-index h3 a { color: var(--c-text); text-decoration: none; }
.k-index__blurb { margin: 0 0 0.4rem; font-size: var(--fs-sm); color: var(--c-muted); }
.k-index ul { list-style: none; margin: 0; padding: 0; }
.k-index ul li { margin: 0; }
.k-index ul a { display: inline-block; padding: 0.22rem 0; text-decoration: none; }
.k-index__more { margin: 0.3rem 0 0; font-size: var(--fs-sm); }
.k-index__more a { color: var(--c-muted); }
.k-hero { padding: clamp(1rem, 4vw, 2.5rem) 0 1rem; }
.k-hero h1 { font-size: var(--fs-hero); max-width: 22ch; }
.k-hero .k-lede { font-size: var(--fs-lg); }
.k-hero__search { display: flex; align-items: center; gap: 0.6rem; width: min(100%, 32rem); min-height: 3.25rem; margin-top: 1rem; padding: 0 1rem; font: inherit; font-size: var(--fs-body); color: var(--c-muted); background: var(--c-field); border: 1px solid var(--c-border-strong); border-radius: var(--radius); cursor: pointer; text-align: left; }
.k-hero__meta { margin: 0.9rem 0 0; font-size: var(--fs-md); color: var(--c-muted); }
.k-hero--split { display: grid; gap: 1.75rem clamp(1.5rem, 4vw, 3.5rem); align-items: start; }
@media (min-width: 60rem) { .k-hero--split { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); } }
.k-hero__text, .k-hero__aside { min-width: 0; }
.k-hero__aside > .tool { margin: 0; }
.k-section-head { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; margin: 2.75rem 0 0.75rem; }
.k-section-head h2 { margin: 0; }
.k-related, .k-faq, .k-sources, .k-byline { margin-top: 2.5rem; }
.k-related__more { margin: 0; }
.k-faq details { border-bottom: 1px solid var(--c-border); }
.k-faq summary { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; padding: 0.8rem 0; font-weight: var(--fw-strong); cursor: pointer; list-style: none; }
.k-faq summary::-webkit-details-marker { display: none; }
.k-faq summary::after { content: ""; flex: none; width: 0.75rem; height: 0.75rem; align-self: center; background: currentColor; opacity: 0.6;
-webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12'%3E%3Cpath d='M2 4.5 6 8.5 10 4.5' fill='none' stroke='black' stroke-width='1.6' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / contain no-repeat;
mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12'%3E%3Cpath d='M2 4.5 6 8.5 10 4.5' fill='none' stroke='black' stroke-width='1.6' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / contain no-repeat;
transition: transform 180ms var(--ease-out), opacity 150ms ease; }
.k-faq details[open] > summary::after { transform: rotate(180deg); opacity: 1; }
.k-faq details > div { padding: 0 0 0.9rem; color: var(--c-text); }
.k-faq details[open] > div { animation: k-settle 180ms var(--ease-out); }
.k-faq details > div > :last-child { margin-bottom: 0; }
.k-sources ul { padding-left: 1.2rem; font-size: var(--fs-md); }
.k-byline { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr)); padding: 1rem 0; border-top: 1px solid var(--c-border); border-bottom: 1px solid var(--c-border); }
.k-byline p { margin: 0; font-size: var(--fs-md); }
.k-byline__role { font-size: var(--fs-xs) !important; text-transform: uppercase; letter-spacing: 0.05em; color: var(--c-muted); }
.k-byline__name { font-weight: var(--fw-bold); }
.k-sisters { margin-top: 3rem; }
.k-sisters ul { display: grid; gap: 0 1.75rem; grid-template-columns: repeat(auto-fill, minmax(min(100%, 17rem), 1fr)); list-style: none; margin: 0; padding: 0; }
.k-sisters li { margin: 0; border-top: 1px solid var(--c-border); }
.k-sisters a { display: flex; flex-direction: column; padding: 0.6rem 0 0.7rem; text-decoration: none; color: var(--c-text); }
.k-sisters a strong { color: var(--c-link); }
.k-sisters a span { font-size: var(--fs-sm); color: var(--c-muted); }
.k-footer { margin-top: 2rem; background: var(--c-footer-bg, var(--c-surface)); color: var(--c-footer-text, var(--c-text)); border-top: 1px solid var(--c-border); }
.k-footer__inner { max-width: var(--w-page); margin: 0 auto; padding: 2.25rem var(--gap) 1.5rem; }
.k-footer__brand { margin-bottom: 1.75rem; }
.k-footer__brand .k-brand { display: inline-flex; padding: 0; min-height: 0; font-size: var(--fs-lead); }
.k-footer__brand .k-brand:hover { text-decoration: none; }
.k-footer__brand .k-brand__logo { width: 1.9rem; height: 1.9rem; }
.k-footer__brand p { margin: 0.5rem 0 0; max-width: 34rem; font-size: var(--fs-sm); color: var(--c-footer-muted, var(--c-muted)); }
.k-footer__cols { display: grid; gap: 1.75rem; grid-template-columns: repeat(auto-fit, minmax(12rem, 1fr)); }
.k-footer h2 { margin: 0 0 0.6rem; font-size: var(--fs-sm); text-transform: uppercase; letter-spacing: 0.06em; color: var(--c-footer-muted, var(--c-muted)); }
.k-footer ul { list-style: none; margin: 0; padding: 0; }
.k-footer li { margin-bottom: 0.15rem; }
.k-footer a { display: inline-block; padding: 0.3rem 0; color: inherit; text-decoration: none; }
.k-footer__sisters span { display: block; font-size: var(--fs-xs); color: var(--c-footer-muted, var(--c-muted)); margin-top: -0.2rem; }
.k-footer__legal { margin: 1.75rem 0 0; padding-top: 1rem; border-top: 1px solid var(--c-border); font-size: var(--fs-sm); color: var(--c-footer-muted, var(--c-muted)); }
.k-consent { position: fixed; left: 1rem; right: 1rem; bottom: 1rem; z-index: 50; display: flex; flex-wrap: wrap; align-items: center; gap: 0.75rem 1.25rem; max-width: 44rem; margin: 0 auto; padding: 0.9rem 1.1rem; background: var(--c-surface); color: var(--c-text); border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); font-size: var(--fs-sm); }
.k-consent[hidden] { display: none; }
.k-consent { transition: opacity 240ms var(--ease-out), transform 240ms var(--ease-out); }
@starting-style { .k-consent { opacity: 0; transform: translateY(0.75rem); } }
@media (max-width: 36rem) {
.k-consent { left: 0.5rem; right: 0.5rem; bottom: 0.5rem; padding: 0.7rem 0.8rem; font-size: var(--fs-sm); gap: 0.5rem; }
.k-consent p { flex-basis: 100%; }
.k-consent__actions { width: 100%; }
.k-consent__actions .k-btn { flex: 1; }
}
.k-consent p { flex: 1 1 16rem; margin: 0; }
.k-consent a { color: inherit; }
.k-consent__actions { display: flex; gap: 0.5rem; }
.k-ad { display: grid; place-items: center; min-height: 280px; margin: 2rem 0; }
@keyframes k-settle { from { opacity: 0; transform: translateY(-0.25rem); } }
@keyframes k-fade { from { opacity: 0; } }
:where(.tool button, .k-btn, .k-icon-btn, .k-search-btn, .k-hero__search):active:not(:disabled) { transform: scale(0.97); }
:where(.k-icon-btn, .k-search-btn, .k-hero__search) { transition: transform 120ms var(--ease-out), background-color 150ms ease, border-color 150ms ease, color 150ms ease; }
.k-copied { position: absolute; z-index: 70; padding: 0.25rem 0.6rem; border-radius: var(--radius); background: var(--c-ink); color: var(--c-on-ink); box-shadow: var(--shadow); font-family: var(--font-sans); font-size: var(--fs-xs); font-weight: var(--fw-strong); line-height: 1.3; white-space: nowrap; pointer-events: none;
opacity: 0; transform: translate(-50%, calc(-100% - 0.2rem)); transition: opacity 160ms var(--ease-out), transform 160ms var(--ease-out); }
.k-copied.is-on { opacity: 1; transform: translate(-50%, calc(-100% - 0.45rem)); }
.k-copied { display: inline-flex; align-items: center; gap: 0.35rem; }
.k-copied::before { content: ""; width: 0.8rem; height: 0.8rem; background: currentColor;
-webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12'%3E%3Cpath d='M2.2 6.4 4.8 9 9.8 3.2' fill='none' stroke='black' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / contain no-repeat;
mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12'%3E%3Cpath d='M2.2 6.4 4.8 9 9.8 3.2' fill='none' stroke='black' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / contain no-repeat; }
:where(.k-btn--ghost, .tool button.k-btn--ghost, .tool button[type="reset"])[data-state="copied"] { color: var(--c-success); border-color: currentColor; }
@media (prefers-reduced-motion: no-preference) {
@view-transition { navigation: auto; }
.k-header { view-transition-name: k-header; }
::view-transition-old(root), ::view-transition-new(root) { animation-duration: 180ms; animation-timing-function: var(--ease-out); }
}
@media (hover: hover) and (pointer: fine) {
a:hover { text-decoration-thickness: 2px; }
.k-nav a:hover { background: var(--c-nav-hover, var(--c-surface-2)); }
.k-search-btn:hover, .k-icon-btn:hover, .k-hero__search:hover { border-color: var(--c-primary); color: var(--c-text); }
.k-search__results a:hover { background: var(--c-primary-soft); }
.tool button:hover, .k-btn:hover { background: var(--c-primary-hover); }
.k-btn--ghost:hover, .tool button.k-btn--ghost:hover, .tool button[type="reset"]:hover { background: var(--c-surface-2); }
.k-card:hover .k-card__title, .k-tile:hover .k-tile__title { text-decoration: underline; text-decoration-thickness: 1px; }
.k-index h3 a:hover, .k-index ul a:hover, .k-footer a:hover, .k-sisters a:hover strong { text-decoration: underline; }
}
@media (prefers-reduced-motion: reduce) {
*, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
:where(.tool button, .k-btn, .k-icon-btn, .k-search-btn, .k-hero__search):active:not(:disabled) { transform: none; }
.k-faq details[open] > div { animation-name: k-fade !important; animation-duration: 160ms !important; }
.k-faq summary::after, .k-consent, .k-copied { transition-property: opacity !important; transition-duration: 160ms !important; }
.k-copied, .k-copied.is-on { transform: translate(-50%, calc(-100% - 0.45rem)); }
.k-faq details[open] > summary::after { transform: none; }
@starting-style { .k-consent { transform: none; } }
}
@media print {
.k-header, .k-footer, .k-consent, .k-related, .k-search, .k-actions, .k-ad { display: none !important; }
body { background: #fff; font-size: 11pt; }
.tool, .k-card { box-shadow: none; }
.k-main { padding: 0; max-width: none; }
}
:root {
--c-bg: #f4f2ec;
--c-surface: #ffffff;
--c-surface-2: #f3f2fb;
--c-field: #ffffff;
--c-text: #1e1b3a;
--c-muted: #5a5873;
--c-border: #e2e0ee;
--c-border-strong: #a9a6c6;
--c-primary: #4338ca;
--c-primary-hover: #3730a3;
--c-on-primary: #ffffff;
--c-primary-soft: #eceefe;
--c-accent: #4338ca;
--c-link: #4338ca;
--c-focus: #4f46e5;
--c-success: #136c43;
--c-success-bg: #e3f4ea;
--c-danger: #b3261e;
--c-danger-bg: #fdecea;
--c-warn: #7a5200;
--c-warn-bg: #fff4d1;
--c-info: #3730a3;
--c-info-bg: #eceefe;
--c-ink: #1e1b4b;
--c-on-ink: #ffffff;
--c-highlight: #ffe98a;
--c-result-bg: #fff3bf;
--c-result-text: #1e1b3a;
--c-mark: #ffe98a;
--c-header-bg: #ffffff;
--c-header-text: #1e1b3a;
--c-header-border: #e2e0ee;
--c-nav-hover: #f3f2fb;
--c-nav-current: #4338ca;
--c-footer-bg: #1e1b4b;
--c-footer-text: #eceafb;
--c-footer-muted: #b9b6e3;
--font-sans: "Inter Variable", "Inter", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
--font-display: var(--font-sans);
--font-num: var(--font-sans);
--radius: 10px;
--radius-lg: 16px;
--h1-weight: 760;
--h1-tracking: -0.025em;
--w-prose: 44rem;
--fs-answer: clamp(1.75rem, 1.2rem + 2.3vw, 2.5rem);
--c-highlight-ink: #5d4a00;
--c-highlight-line: rgb(93 74 0 / 0.22);
--c-highlight-soft: #fffbea;
}
body { font-feature-settings: "cv05", "cv08", "ss03"; }
.k-brand__mark { background: var(--c-primary); color: var(--c-highlight); }
.k-footer { border-top: 0; }
.k-footer__legal { border-top-color: rgb(255 255 255 / 0.16); }
.k-page--tool, .k-page--guide, .k-page--plain {
max-width: calc(var(--w-prose) + 2 * clamp(1rem, 4vw, 2.75rem));
padding: clamp(1rem, 4vw, 2.75rem);
background: var(--c-surface);
border: 1px solid var(--c-border);
border-radius: var(--radius-lg);
}
@media (max-width: 40rem) {
.k-main { padding-top: 0; }
.k-page--tool, .k-page--guide, .k-page--plain { margin: 0 calc(var(--gap) * -1); padding: 1rem var(--gap) 1.5rem; border-width: 0 0 1px; border-radius: 0; }
.k-page--tool .k-lede { font-size: var(--fs-md); margin-bottom: 0.4rem; }
.k-page--tool h1 { margin-bottom: 0.3rem; }
.k-page--tool .k-page__head { margin-bottom: 0.6rem; }
}
.k-prose h2 { padding-top: 0.25rem; }
.k-formula.cw-formula { font-family: inherit; font-size: var(--fs-body); padding: 0.75rem 1rem; background: var(--c-surface-2); border-radius: var(--radius); overflow-x: auto; overflow-y: hidden; }
.cw-formula .katex-display { margin: 0.35rem 0; }
.katex { font-size: 1.12em; }
.tool.cw { margin-top: 0.75rem; background: var(--c-surface-2); border-color: var(--c-border); box-shadow: none; }
.cw-form { grid-template-columns: repeat(auto-fit, minmax(8.5rem, 1fr)); gap: 0.75rem 0.9rem; align-items: start; }
.cw-form fieldset { min-width: 0; margin: 0; padding: 0; border: 0; }
.cw-form legend.k-label { padding: 0; margin-bottom: 0.3rem; font-weight: var(--fw-strong); font-size: var(--fs-md); }
.cw-form textarea { min-height: 4.5rem; font-variant-numeric: tabular-nums; }
.cw-form input, .cw-form select { width: 100%; font-variant-numeric: tabular-nums; }
.cw-form__intro { margin: 0; font-size: var(--fs-lead); font-weight: var(--fw-strong); letter-spacing: 0.01em; }
.cw-form--three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.cw-form--four { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.cw-group__fields { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.5rem; }
.cw-group .k-field > label { font-weight: var(--fw-medium); color: var(--c-muted); }
.cw-form--four input, .cw-form--three input { padding-left: 0.55rem !important; padding-right: 0.4rem !important; }
.cw-seg .k-segmented { align-self: flex-start; flex-wrap: wrap; background: var(--c-surface); border: 1px solid var(--c-border-strong); }
.cw-seg .k-segmented input:checked + span { background: var(--c-primary); color: var(--c-on-primary); box-shadow: none; }
.cw-seg .k-segmented span { min-width: 2.6rem; text-align: center; }
.cw-form--fractions { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 0.9rem 1.25rem; }
.cw-fracin__row { display: flex; align-items: center; gap: 0.6rem; }
.cw-fracin__part { display: flex; flex-direction: column; gap: 0.15rem; }
.cw-fracin__part label { font-size: var(--fs-2xs); font-weight: var(--fw-medium); color: var(--c-muted); }
.cw-fracin__part input { width: 4.6rem; text-align: center; }
.cw-fracin__stack { display: flex; flex-direction: column; gap: 0.3rem; }
.cw-fracin__stack .cw-fracin__part { flex-direction: row; align-items: center; gap: 0.45rem; }
.cw-fracin__stack .cw-fracin__part label { order: 2; }
.cw-fracin__part--n input { border-bottom: 3px solid var(--c-text) !important; }
.cw-answer { margin-top: 1rem; }
.cw-answer.is-waiting { background: var(--c-surface); }
.cw-answer .k-result__label { color: var(--c-highlight-ink); }
.cw-answer .k-result__value { line-height: 1.2; letter-spacing: -0.01em; overflow-wrap: anywhere; }
.cw-answer .k-result__note { color: var(--c-highlight-ink); }
.cw-answer__msg { margin: 0.2rem 0 0; font-size: var(--fs-lead); font-weight: var(--fw-strong); }
.cw-more { display: grid; gap: 0.5rem 1.25rem; grid-template-columns: repeat(auto-fit, minmax(10.5rem, 1fr)); margin: 0.85rem 0 0; padding-top: 0.75rem; border-top: 1px solid var(--c-highlight-line); }
.cw-more dt { font-size: var(--fs-xs); color: var(--c-highlight-ink); }
.cw-more dd { margin: 0; font-weight: var(--fw-strong); overflow-wrap: anywhere; }
.cw-actions { margin-top: 0.75rem; }
.cw-plotwrap { margin-top: 0.9rem; padding: 0.5rem; background: var(--c-surface); border-radius: var(--radius); }
.cw-plotwrap:empty { display: none; }
.cw-plot { display: block; width: 100%; max-width: 30rem; height: auto; margin: 0 auto; }
.cw-plot__frame { fill: var(--c-surface-2); stroke: var(--c-border); }
.cw-plot__axis { stroke: var(--c-border-strong); stroke-width: 1; }
.cw-plot__line { fill: none; stroke: var(--c-primary); stroke-width: 2.25; stroke-linejoin: round; stroke-linecap: round; }
.cw-plot__dot { fill: var(--c-primary); stroke: #ffffff; stroke-width: 1.5; }
.cw-plot__dot--alt { fill: var(--c-warn); }
.cw-plot__label, .cw-plot__tick { font-family: var(--font-sans); font-size: var(--fs-2xs); fill: var(--c-muted); }
.cw-plot__label { font-size: var(--fs-2xs); fill: var(--c-text); font-weight: var(--fw-strong); paint-order: stroke; stroke: #ffffff; stroke-width: 3px; }
.cw-steps { margin-top: 1rem; background: var(--c-surface); border-radius: var(--radius); }
.cw-steps > summary { display: flex; flex-wrap: wrap; align-items: baseline; gap: 0.2rem 0.75rem; padding: 0.8rem 1rem; cursor: pointer; font-weight: var(--fw-bold); color: var(--c-primary); }
@media (hover: hover) and (pointer: fine) { .cw-steps > summary:hover { background: var(--c-primary-soft); border-radius: var(--radius); } }
.cw-steps[open] > summary { border-bottom: 1px solid var(--c-border); border-radius: var(--radius) var(--radius) 0 0; }
.cw-steps[open] .cw-steps__label::before { content: "Hide steps"; }
.cw-steps:not([open]) .cw-steps__label::before { content: "Show steps"; }
.cw-steps__label { font-size: 0; }
.cw-steps__label::before { font-size: var(--fs-body); }
.cw-steps__tag { font-size: var(--fs-sm); font-weight: var(--fw-medium); color: var(--c-muted); }
.cw-steps > div { padding: 1rem 1rem 0.25rem; }
.cw-steplist { margin-bottom: 0; }
@keyframes cw-step-in { from { opacity: 0; transform: translateY(0.375rem); } }
.cw-unfold .cw-steplist > li { animation: cw-step-in 240ms var(--ease-out) both; }
.cw-unfold .cw-steplist > li:nth-child(2) { animation-delay: 45ms; }
.cw-unfold .cw-steplist > li:nth-child(3) { animation-delay: 90ms; }
.cw-unfold .cw-steplist > li:nth-child(4) { animation-delay: 135ms; }
.cw-unfold .cw-steplist > li:nth-child(5) { animation-delay: 180ms; }
.cw-unfold .cw-steplist > li:nth-child(n + 6) { animation-delay: 225ms; }
.cw-step__title { margin: 0 0 0.3rem; font-weight: var(--fw-strong); }
.cw-step__math { margin: 0 0 0.3rem; font-size: var(--fs-lead); font-variant-numeric: tabular-nums; line-height: 1.9; overflow-wrap: anywhere; }
.cw-step__note { margin: 0.1rem 0 0; font-size: var(--fs-sm); color: var(--c-muted); }
.cw-steplist .k-table-wrap { margin: 0.4rem 0 0.5rem; }
.cw-table { width: 100%; min-width: 0 !important; border-collapse: collapse; font-size: var(--fs-md); font-variant-numeric: tabular-nums; }
.cw-table th, .cw-table td { padding: 0.35rem 0.6rem; border-bottom: 1px solid var(--c-border); text-align: right; white-space: nowrap; }
.cw-table thead th { font-size: var(--fs-xs); text-transform: none; letter-spacing: 0; color: var(--c-muted); border-bottom: 2px solid var(--c-border-strong); }
.cw-table tfoot td { font-weight: var(--fw-bold); border-bottom: 0; border-top: 2px solid var(--c-border-strong); }
.cw-tableau { display: inline-block; max-width: 100%; margin: 0.5rem 0; padding: 0.75rem 1rem; overflow-x: auto; font-family: var(--font-mono); font-size: var(--fs-md); line-height: 1.3; background: var(--c-surface-2); border: 1px solid var(--c-border); border-radius: var(--radius); }
.cw-frac { display: inline-flex; flex-direction: column; align-items: center; margin: 0 0.12em; vertical-align: middle; font-size: 0.88em; line-height: 1.15; text-align: center; white-space: nowrap; }
.cw-frac > span:first-child { padding: 0 0.3em 0.08em; border-bottom: 0.09em solid currentColor; }
.cw-frac > span:last-child { padding: 0.08em 0.3em 0; }
.cw-rep { text-decoration: overline; text-decoration-thickness: 0.08em; }
.k-steps mark, .cw-worked__value { background: var(--c-mark); color: inherit; padding: 0.05em 0.3em; border-radius: 4px; box-decoration-break: clone; -webkit-box-decoration-break: clone; }
.cw-step__math sup, .k-result__value sup { font-size: 0.68em; }
.cw-worked, .cw-practice { margin: 0 0 1rem; padding: 1rem 1.1rem 0.6rem; background: var(--c-surface-2); border-radius: var(--radius); }
.cw-worked__answer { margin: 0.25rem 0 0.5rem; font-size: var(--fs-lead); }
.cw-worked__link { margin: 0 0 0.4rem; font-size: var(--fs-sm); }
.cw-practice { background: var(--c-highlight-soft); }
.cw-practice__q { margin: 0 0 0.6rem; font-size: var(--fs-lead); font-weight: var(--fw-strong); }
.cw-practice summary { padding: 0.35rem 0; cursor: pointer; font-weight: var(--fw-strong); color: var(--c-link); }
.cw-practice details[open] summary { margin-bottom: 0.6rem; }
.cw-intro { max-width: var(--w-prose); margin-top: 0; }
.cw-how { max-width: var(--w-prose); }
.k-hub__intro { max-width: var(--w-prose); }
.tool:not(.cw) > div { margin-bottom: 1rem; }
.tool:not(.cw) > div:last-child { margin-bottom: 0; }
.tool:not(.cw) label { display: block; margin-bottom: 0.3rem; }
.tool:not(.cw) label:has(> input[type="radio"]), .tool:not(.cw) label:has(> input[type="checkbox"]) { display: flex; align-items: center; gap: 0.5rem; margin-bottom: 0.45rem; font-weight: var(--fw-medium); cursor: pointer; }
.tool:not(.cw) input[type="radio"] + label, .tool:not(.cw) input[type="checkbox"] + label { display: inline-block; margin-left: 0.35rem; font-weight: var(--fw-medium); }
.tool:not(.cw) input:not([type="checkbox"]):not([type="radio"]):not([type="range"]):not([type="color"]):not([type="file"]),
.tool:not(.cw) select, .tool:not(.cw) textarea { width: 100%; max-width: 26rem; margin: 0 0.4rem 0.6rem 0; }
.tool:not(.cw) button { margin: 0.2rem 0.4rem 0.4rem 0; }
.tool:not(.cw) fieldset { margin: 0 0 1rem; padding: 0.75rem 1rem; border: 1px solid var(--c-border-strong); border-radius: var(--radius); }
.tool:not(.cw) legend { padding: 0 0.4rem; font-weight: var(--fw-strong); }
.tool:not(.cw) canvas, .tool:not(.cw) svg { max-width: 100%; height: auto; }
.tool:not(.cw) pre { overflow-x: auto; }
.cw-novelty { display: inline-block; margin: 0 0 0.75rem; }
.tool.cw .cw-form .k-field > label { display: block; margin: 0; }
.tool.cw .cw-form .k-field > input, .tool.cw .cw-form .k-field > select, .tool.cw .cw-form .k-field > textarea { width: 100% !important; }
.k-brand__name span { color: var(--c-primary); }
.k-footer .k-brand__name span { color: var(--c-highlight); }
.cw-example { margin: 0; padding: 1.25rem 1.4rem 1.1rem; background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius-lg); }
.cw-example__problem { margin: 0 0 1rem; padding-bottom: 0.8rem; border-bottom: 1px solid var(--c-border); font-size: var(--fs-xl); font-weight: var(--fw-bold); letter-spacing: -0.01em; }
.cw-example .k-steps { margin-bottom: 0.4rem; }
.cw-example .k-steps > li { padding-bottom: 0.7rem; }
.cw-example__answer { margin: 0 0 1rem; font-size: var(--fs-xl); font-weight: 800; letter-spacing: -0.01em; }
.cw-example__answer mark { position: relative; z-index: 0; padding: 0.05em 0.3em; background: none; color: var(--c-ink); }
.cw-example__answer mark::before { content: ""; position: absolute; inset: 0; z-index: -1; border-radius: 4px; background: var(--c-highlight); transform-origin: left center; }
@keyframes cw-mark { from { transform: scaleX(0); } }
@media (prefers-reduced-motion: no-preference) {
.cw-example .k-steps > li { animation: cw-step-in 320ms var(--ease-out) both; }
.cw-example .k-steps > li:nth-child(1) { animation-delay: 150ms; }
.cw-example .k-steps > li:nth-child(2) { animation-delay: 330ms; }
.cw-example .k-steps > li:nth-child(3) { animation-delay: 510ms; }
.cw-example__answer mark::before { animation: cw-mark 420ms var(--ease-out) 780ms both; }
}
.cw-example figcaption { font-size: var(--fs-sm); color: var(--c-muted); }