:root {
  --doc-bg: #FDFDFF;
  --doc-panel: #FFFFFF;
  --doc-soft: #F5F6FA;
  --doc-ink: #050505;
  --doc-muted: #6E6E6E;
  --doc-line: rgba(5, 5, 5, .12);
  --doc-line-strong: rgba(5, 5, 5, .22);
  --doc-dark: #272727;
  --doc-accent: #375DFF;
  --doc-wrap: min(1220px, 92vw);
}

* {
  box-sizing: border-box;
}

html {
  background: var(--doc-bg);
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--doc-bg);
  color: var(--doc-ink);
  font-family: "DM Sans", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 18px;
  line-height: 1.55;
  letter-spacing: -0.05em;
}

a {
  color: inherit;
}

:focus-visible {
  outline: 2px solid #111;
  outline-offset: 3px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  background: rgba(255,255,255,.86);
  border-bottom: 1px solid var(--doc-line);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
}

.nav {
  width: var(--doc-wrap);
  height: 68px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 22px;
}

.brand {
  color: var(--doc-ink);
  text-decoration: none;
  font-family: "Space Grotesk", "DM Sans", system-ui, sans-serif;
  font-weight: 700;
  font-size: 19px;
  line-height: 1;
}

.links {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 18px;
}

.links a {
  color: #1f1f1f;
  text-decoration: none;
  font-size: 16px;
  font-weight: 500;
  line-height: 1;
}

.menu-toggle {
  display: none;
}

main {
  padding-top: 68px;
}

.eyebrow {
  margin: 0 0 12px;
  color: #77878B;
  font-family: "Unbounded", sans-serif;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  line-height: 1;
  text-transform: uppercase;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  color: var(--doc-ink);
  font-family: "Space Grotesk", "DM Sans", system-ui, sans-serif;
  font-weight: 700;
  letter-spacing: -0.055em;
  line-height: 1.06;
}

p {
  margin: 0;
  color: var(--doc-muted);
}

.doc-index-hero {
  width: var(--doc-wrap);
  min-height: 500px;
  margin: 0 auto;
  padding: 118px 0 64px;
  display: grid;
  align-content: end;
  gap: 24px;
}

.doc-index-hero h1 {
  max-width: 1000px;
  font-size: clamp(50px, 7vw, 104px);
  text-transform: uppercase;
}

.doc-index-hero p:not(.eyebrow) {
  max-width: 760px;
  font-size: clamp(21px, 2vw, 28px);
  line-height: 1.22;
}

.doc-button-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
}

.doc-list {
  width: var(--doc-wrap);
  margin: 0 auto;
  padding: 50px 0 108px;
}

.doc-list-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 440px);
  gap: 28px;
  align-items: end;
  margin-bottom: 28px;
}

.doc-list-head h2 {
  font-size: clamp(34px, 4vw, 58px);
  text-transform: uppercase;
}

.doc-list-head p {
  margin-top: 12px;
  max-width: 720px;
  font-size: 20px;
  line-height: 1.32;
}

.doc-toolbar {
  display: flex;
  justify-content: flex-end;
  gap: 14px;
  flex-wrap: wrap;
  align-items: center;
}

.doc-toolbar input,
.doc-toolbar select {
  height: 46px;
  border: 1px solid var(--doc-line);
  border-radius: 999px;
  background: #fff;
  color: var(--doc-ink);
  font: 400 15px/1 "DM Sans", system-ui, sans-serif;
  letter-spacing: -0.04em;
}

.doc-toolbar input {
  width: min(460px, 100%);
  padding: 0 18px;
  font-size: 16px;
}

.doc-toolbar select {
  width: auto;
  padding: 0 38px 0 15px;
  font-family: "Unbounded", sans-serif;
  letter-spacing: -0.05em;
  appearance: none;
  background-image:
    linear-gradient(45deg, transparent 50%, #111 50%),
    linear-gradient(135deg, #111 50%, transparent 50%);
  background-position:
    calc(100% - 18px) 20px,
    calc(100% - 13px) 20px;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
}

.docs-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.doc-card {
  position: relative;
  min-height: 360px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 28px;
  padding: 24px;
  border: 1px solid #ECECEC;
  background: #fff;
  color: inherit;
  text-decoration: none;
  overflow: hidden;
  transition: transform .28s ease, border-color .28s ease, box-shadow .28s ease;
}

.doc-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 3px;
  background: linear-gradient(90deg, #375DFF, #7C3AED, #E75D2A);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .28s ease;
}

.doc-card:hover {
  transform: translateY(-6px);
  border-color: #DADADA;
  box-shadow: 0 20px 40px rgba(0,0,0,.08);
}

.doc-card:hover::before {
  transform: scaleX(1);
}

.doc-card-meta {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  color: var(--doc-muted);
  font-family: "Unbounded", sans-serif;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .06em;
  line-height: 1.2;
  text-transform: uppercase;
}

.doc-card h3 {
  margin-top: auto;
  font-size: clamp(25px, 3vw, 36px);
  text-transform: uppercase;
}

.doc-card p {
  margin-top: 12px;
  font-size: 17px;
  line-height: 1.32;
}

.doc-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.doc-tags span {
  border: 1px solid var(--doc-line);
  padding: 7px 9px;
  color: var(--doc-muted);
  font-size: 12px;
  line-height: 1;
  text-transform: uppercase;
}

.doc-arrow {
  position: absolute;
  right: 24px;
  bottom: 22px;
  font-size: 30px;
  line-height: 1;
  transition: transform .28s ease;
}

.doc-card:hover .doc-arrow {
  transform: translateX(4px);
}

.course-layout {
  width: var(--doc-wrap);
  margin: 0 auto;
  padding: 108px 0 96px;
  display: grid;
  grid-template-columns: 290px minmax(0, 1fr);
  gap: 36px;
  align-items: start;
}

.doc-toc {
  position: sticky;
  top: 96px;
  padding: 24px;
  border-radius: 12px;
  background: var(--doc-dark);
  color: #fff;
}

.doc-toc h2 {
  margin-bottom: 20px;
  color: #fff;
  font-size: 26px;
  text-transform: uppercase;
}

.doc-toc a {
  display: block;
  margin-top: 12px;
  padding: 13px 14px;
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 8px;
  background: rgba(255,255,255,.07);
  color: #fff;
  text-decoration: none;
  font-size: 15px;
  line-height: 1.2;
  transition: transform .18s ease, background .18s ease, border-color .18s ease;
}

.doc-toc a:hover {
  transform: translateY(-1px);
  border-color: rgba(255,255,255,.34);
  background: rgba(255,255,255,.12);
}

.doc-article {
  display: grid;
  gap: 24px;
}

.doc-article-hero,
.doc-panel {
  border: 1px solid var(--doc-line);
  border-radius: 12px;
  background: var(--doc-panel);
  box-shadow: 0 8px 24px rgba(5,5,5,.05);
}

.doc-article-hero {
  padding: 34px 34px 38px;
}

.doc-article-hero h1 {
  max-width: 980px;
  font-size: clamp(42px, 5vw, 72px);
  text-transform: uppercase;
}

.doc-article-hero p:not(.eyebrow) {
  margin-top: 18px;
  max-width: 820px;
  font-size: 21px;
  line-height: 1.35;
}

.doc-panel {
  padding: 30px 32px;
}

.doc-panel h2 {
  margin-bottom: 16px;
  font-size: clamp(28px, 3vw, 40px);
  text-transform: uppercase;
}

.doc-panel h3 {
  margin: 22px 0 10px;
  font-size: 23px;
  text-transform: uppercase;
}

.doc-panel p,
.doc-panel li {
  color: var(--doc-muted);
  font-size: 17px;
  line-height: 1.62;
}

.doc-panel p + p,
.doc-panel ul + p,
.doc-panel ol + p,
.doc-callout + p,
.doc-code + p,
.doc-table + p {
  margin-top: 16px;
}

.doc-panel ul,
.doc-panel ol {
  margin: 14px 0 0;
  padding-left: 22px;
}

.doc-panel li + li {
  margin-top: 8px;
}

.doc-callout {
  margin-top: 18px;
  padding: 17px 18px;
  border-left: 4px solid var(--doc-accent);
  border-radius: 0 10px 10px 0;
  background: rgba(55,93,255,.07);
}

.doc-callout strong {
  display: block;
  margin-bottom: 5px;
  color: var(--doc-ink);
}

.doc-code {
  margin-top: 18px;
  border: 1px solid rgba(5,5,5,.12);
  border-radius: 12px;
  overflow: hidden;
  background: #272727;
}

.doc-code-header {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding: 11px 14px;
  border-bottom: 1px solid rgba(255,255,255,.12);
  color: rgba(255,255,255,.72);
  font-size: 12px;
}

.doc-code pre {
  margin: 0;
  padding: 18px;
  overflow: auto;
  color: #FDFDFF;
  font: 14px/1.62 Consolas, Menlo, "Courier New", monospace;
  letter-spacing: 0;
  white-space: pre-wrap;
}

.doc-table {
  width: 100%;
  margin-top: 18px;
  border: 1px solid var(--doc-line);
  border-collapse: collapse;
  table-layout: fixed;
  background: #fff;
}

.doc-table th,
.doc-table td {
  padding: 14px 15px;
  border-bottom: 1px solid var(--doc-line);
  vertical-align: top;
  text-align: left;
  overflow-wrap: anywhere;
}

.doc-table th {
  background: var(--doc-soft);
  color: var(--doc-ink);
  font-family: "Space Grotesk", system-ui, sans-serif;
  font-size: 14px;
  line-height: 1.25;
  text-transform: uppercase;
}

.doc-table td {
  color: var(--doc-muted);
  font-size: 16px;
}

.color-token {
  display: inline-flex;
  align-items: center;
  min-height: 1.55em;
  margin-left: 4px;
  margin-right: 2px;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--swatch);
  color: #111;
  font-family: Consolas, Menlo, "Courier New", monospace;
  font-size: .86em;
  font-weight: 700;
  letter-spacing: 0;
  white-space: nowrap;
  vertical-align: baseline;
  box-shadow: inset 0 0 0 1px rgba(0,0,0,.12);
}

.color-token.light {
  color: #fff;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.18);
}

.color-token.dark {
  color: #111;
}

.doc-media,
.doc-panel .media {
  width: 100%;
  max-width: 760px;
  margin: 18px auto;
  overflow: hidden;
  border: 1px solid var(--doc-line);
  border-radius: 12px;
  background: #fff;
}

.doc-media img,
.doc-panel .media img {
  display: block;
  width: 100%;
  height: auto;
}

.doc-media figcaption,
.doc-panel .media figcaption {
  padding: 12px 14px;
  color: var(--doc-muted);
  background: var(--doc-soft);
  font-size: 14px;
  line-height: 1.35;
}

.doc-compare-head .hint {
  margin-top: 8px;
}

.doc-compare-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 18px;
}

.doc-pane {
  overflow: hidden;
  border: 1px solid var(--doc-line);
  border-radius: 12px;
  background: #fff;
}

.doc-pane header {
  padding: 12px 14px;
  border-bottom: 1px solid var(--doc-line);
  background: var(--doc-soft);
}

.doc-pane header strong {
  color: var(--doc-ink);
  font-family: "Space Grotesk", system-ui, sans-serif;
  font-size: 18px;
}

.doc-pane-body {
  padding: 14px 16px;
  color: var(--doc-muted);
  font-size: 17px;
  line-height: 1.5;
}

.doc-pane-body.emphasis {
  border-left: 4px solid var(--doc-accent);
  background: rgba(55,93,255,.06);
  color: var(--doc-ink);
}

.doc-equation {
  margin: 18px 0;
  padding: 16px 18px;
  overflow-x: auto;
  border: 1px solid var(--doc-line);
  border-radius: 12px;
  background: var(--doc-soft);
}

.doc-equation .math {
  min-width: max-content;
  color: var(--doc-ink);
  font-family: ui-serif, "STIX Two Math", "Cambria Math", "Times New Roman", serif;
  font-size: 1.1em;
  letter-spacing: 0;
  line-height: 1.45;
}

.frac {
  display: inline-block;
  vertical-align: middle;
  text-align: center;
}

.frac .top {
  display: block;
  padding: 0 .25em .1em;
  border-bottom: 1px solid currentColor;
}

.frac .bottom {
  display: block;
  padding: .1em .25em 0;
}

.sum {
  display: inline-block;
  position: relative;
  margin: 0 .1em;
  font-size: 1.18em;
  line-height: 1;
}

.sum .sub {
  position: absolute;
  left: 50%;
  top: 1.05em;
  transform: translateX(-50%);
  font-size: .5em;
  white-space: nowrap;
}

.doc-bottom-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 4px;
}

@media (max-width: 980px) {
  .links {
    display: none;
  }

  .doc-list-head,
  .course-layout {
    grid-template-columns: 1fr;
  }

  .doc-toc {
    position: static;
  }

  .docs-grid {
    grid-template-columns: 1fr;
  }

  .doc-compare-grid {
    grid-template-columns: 1fr;
  }

  .doc-index-hero,
  .doc-list,
  .course-layout {
    padding-left: 0;
    padding-right: 0;
  }

  .doc-article-hero,
  .doc-panel {
    padding: 24px 20px;
  }
}

@media (max-width: 620px) {
  .doc-index-hero {
    min-height: auto;
    padding-top: 86px;
  }

  .doc-index-hero h1,
  .doc-article-hero h1 {
    font-size: 42px;
  }

  .doc-card {
    min-height: 320px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}