:root {
  --zr-bg: #fcfcfa;
  --zr-raised: #f3f3ef;
  --zr-ink: #16181b;
  --zr-muted: #565b61;
  --zr-line: #e2e2dc;
  --zr-line-strong: #c9c9c1;
  --zr-accent: #0f766e;
  --zr-accent-deep: #0b5a54;
  --zr-accent-soft: #e3f1ef;
  --zr-mono: ui-monospace, "SFMono-Regular", "Cascadia Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --zr-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --zr-wide: 1000px;
  --zr-gap: 20px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--zr-bg);
  color: var(--zr-ink);
  font-family: var(--zr-sans);
  font-size: 16px;
  line-height: 1.65;
}

h1,
h2,
h3 {
  font-family: var(--zr-mono);
  font-weight: 500;
  line-height: 1.22;
  letter-spacing: -0.01em;
  margin: 0 0 14px;
}

h1 {
  font-size: clamp(1.75rem, 4.6vw, 2.6rem);
}

h2 {
  font-size: clamp(1.3rem, 3vw, 1.7rem);
}

h3 {
  font-size: 1.06rem;
}

p {
  margin: 0 0 14px;
}

a {
  color: var(--zr-accent-deep);
  text-underline-offset: 3px;
}

a:hover {
  color: var(--zr-ink);
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--zr-accent);
  outline-offset: 2px;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

table {
  border-collapse: collapse;
  width: 100%;
}

.zr-skip {
  position: absolute;
  left: 12px;
  top: -60px;
  background: var(--zr-ink);
  color: #ffffff;
  padding: 10px 14px;
  font-family: var(--zr-mono);
  z-index: 20;
}

.zr-skip:focus {
  top: 12px;
  color: #ffffff;
}

.zr-wrap {
  max-width: var(--zr-wide);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--zr-gap);
  padding-right: var(--zr-gap);
}

.zr-head {
  border-bottom: 1px solid var(--zr-line);
  background: var(--zr-bg);
}

.zr-head__in {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 20px;
  padding-top: 12px;
  padding-bottom: 12px;
}

.zr-head__brand {
  font-family: var(--zr-mono);
  font-size: 1.05rem;
  color: var(--zr-ink);
  text-decoration: none;
  display: inline-block;
  padding: 10px 0;
}

.zr-head__brand span {
  color: var(--zr-accent);
}

.zr-head__nav {
  display: flex;
  align-items: center;
  gap: 4px 18px;
  overflow-x: auto;
  max-width: 100%;
}

.zr-head__link {
  font-family: var(--zr-mono);
  font-size: 0.86rem;
  color: var(--zr-muted);
  text-decoration: none;
  white-space: nowrap;
  display: inline-block;
  padding: 12px 0;
}

.zr-head__link:hover,
.zr-head__link.is-active {
  color: var(--zr-ink);
}

.zr-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 14px 26px;
  background: var(--zr-accent);
  color: #ffffff;
  border: 1px solid var(--zr-accent);
  font-family: var(--zr-mono);
  font-size: 0.9rem;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 140ms ease, color 140ms ease;
}

.zr-btn:hover {
  background: var(--zr-accent-deep);
  color: #ffffff;
}

.zr-btn--ghost {
  background: transparent;
  color: var(--zr-ink);
  border-color: var(--zr-line-strong);
}

.zr-btn--ghost:hover {
  background: var(--zr-raised);
  color: var(--zr-ink);
}

.zr-btn--small {
  padding: 10px 16px;
  font-size: 0.82rem;
}

.zr-trail {
  font-family: var(--zr-mono);
  font-size: 0.82rem;
  color: var(--zr-muted);
  padding-top: 14px;
  padding-bottom: 4px;
}

.zr-trail a {
  display: inline-block;
  padding: 12px 0;
}

.zr-tag {
  display: inline-block;
  font-family: var(--zr-mono);
  font-size: 0.8rem;
  color: var(--zr-accent-deep);
  margin-bottom: 10px;
}

.zr-meta {
  font-family: var(--zr-mono);
  font-size: 0.82rem;
  color: var(--zr-muted);
}

.zr-hero {
  padding-top: 40px;
  padding-bottom: 44px;
  border-bottom: 1px solid var(--zr-line);
}

.zr-hero__grid {
  display: grid;
  gap: 28px;
}

.zr-hero__sub {
  font-size: 1.08rem;
  color: var(--zr-muted);
  max-width: 60ch;
}

.zr-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.zr-hero__shot {
  border: 1px solid var(--zr-line-strong);
  background: var(--zr-raised);
  margin: 0;
}

.zr-hero__shot figcaption {
  font-family: var(--zr-mono);
  font-size: 0.78rem;
  color: var(--zr-muted);
  padding: 8px 10px;
  border-top: 1px solid var(--zr-line);
}

.zr-lead {
  padding-top: 26px;
  padding-bottom: 30px;
}

.zr-lead__sub {
  font-size: 1.06rem;
  color: var(--zr-muted);
  max-width: 64ch;
}

.zr-cover {
  background: var(--zr-ink);
  color: #f2f2ee;
  padding-top: 64px;
  padding-bottom: 64px;
}

.zr-cover h1 {
  max-width: 20ch;
}

.zr-cover__line {
  font-family: var(--zr-mono);
  color: #b9c0c6;
  max-width: 56ch;
}

.zr-cover .zr-tag {
  color: #7fd3c9;
}

.zr-cover .zr-btn--ghost {
  color: #f2f2ee;
  border-color: #6a7076;
}

.zr-cover .zr-btn--ghost:hover {
  background: #26292d;
}

.zr-narrow {
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--zr-gap);
  padding-right: var(--zr-gap);
}

.zr-sect {
  padding-top: 44px;
  padding-bottom: 20px;
}

.zr-sect--tight {
  padding-top: 26px;
}

.zr-sect__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
  margin-bottom: 8px;
}

.zr-sect__num {
  font-family: var(--zr-mono);
  color: var(--zr-accent-deep);
  font-size: 0.9rem;
}

.zr-ladder {
  list-style: none;
  margin: 0;
  padding: 0;
}

.zr-rung {
  position: relative;
  padding-left: 64px;
  padding-bottom: 36px;
}

.zr-rung::before {
  content: "";
  position: absolute;
  left: 21px;
  top: 44px;
  bottom: 0;
  width: 1px;
  background: var(--zr-line-strong);
}

.zr-rung:last-child::before {
  display: none;
}

.zr-rung__num {
  position: absolute;
  left: 0;
  top: 0;
  width: 43px;
  height: 43px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--zr-accent);
  font-family: var(--zr-mono);
  color: var(--zr-accent-deep);
  background: var(--zr-bg);
}

.zr-rung__title {
  padding-top: 8px;
}

.zr-zig {
  display: grid;
  gap: 22px;
  align-items: start;
  padding-top: 34px;
  padding-bottom: 34px;
}

.zr-zig > * {
  min-width: 0;
}

.zr-zig__media {
  margin: 0;
}

.zr-zig__media figcaption,
.zr-shot figcaption {
  font-family: var(--zr-mono);
  font-size: 0.78rem;
  color: var(--zr-muted);
  margin-top: 8px;
}

.zr-shot {
  margin: 22px 0;
}

.zr-shot img {
  border: 1px solid var(--zr-line-strong);
}

.zr-shot--tall img {
  max-width: 300px;
}

.zr-band {
  padding-top: 46px;
  padding-bottom: 30px;
}

.zr-band--raised {
  background: var(--zr-raised);
  border-top: 1px solid var(--zr-line);
  border-bottom: 1px solid var(--zr-line);
}

.zr-cards {
  display: grid;
  gap: 16px;
  align-items: start;
  margin-top: 18px;
}

.zr-card {
  border: 1px solid var(--zr-line-strong);
  background: var(--zr-bg);
  padding: 18px;
}

.zr-card__label {
  font-family: var(--zr-mono);
  font-size: 0.78rem;
  color: var(--zr-accent-deep);
  margin-bottom: 6px;
}

.zr-card p:last-child {
  margin-bottom: 0;
}

.zr-bento {
  display: grid;
  gap: 14px;
  margin-top: 18px;
}

.zr-tile {
  border: 1px solid var(--zr-line-strong);
  background: var(--zr-raised);
  padding: 18px;
}

.zr-tile__big {
  font-family: var(--zr-mono);
  font-size: clamp(2rem, 6vw, 3rem);
  line-height: 1;
  color: var(--zr-accent-deep);
  margin-bottom: 10px;
}

.zr-tile p:last-child {
  margin-bottom: 0;
}

.zr-split {
  display: block;
}

.zr-split__side {
  padding-top: 30px;
  padding-bottom: 10px;
}

.zr-split__body {
  min-width: 0;
  padding-bottom: 20px;
}

.zr-offset {
  display: grid;
  gap: 0 20px;
}

.zr-offset__block {
  min-width: 0;
  padding-top: 34px;
  padding-bottom: 12px;
}

.zr-compare {
  padding-top: 20px;
  padding-bottom: 24px;
}

.zr-compare__notes {
  display: grid;
  gap: 14px;
  margin-top: 18px;
}

.zr-note {
  border-left: 2px solid var(--zr-accent);
  padding: 4px 0 4px 14px;
}

.zr-note p:last-child {
  margin-bottom: 0;
}

.zr-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--zr-line-strong);
  margin-top: 14px;
  background: var(--zr-bg);
}

.zr-table {
  min-width: 620px;
  font-size: 0.93rem;
}

.zr-table caption {
  text-align: left;
  font-family: var(--zr-mono);
  font-size: 0.82rem;
  color: var(--zr-muted);
  padding: 10px 12px;
  border-bottom: 1px solid var(--zr-line);
}

.zr-table th,
.zr-table td {
  text-align: left;
  vertical-align: top;
  padding: 10px 12px;
  border-bottom: 1px solid var(--zr-line);
}

.zr-table thead th {
  font-family: var(--zr-mono);
  font-weight: 500;
  font-size: 0.8rem;
  color: var(--zr-muted);
  background: var(--zr-raised);
}

.zr-table tbody th {
  font-weight: 600;
}

.zr-table tbody tr:last-child th,
.zr-table tbody tr:last-child td {
  border-bottom: 0;
}

.zr-source {
  font-style: italic;
  font-size: 0.88rem;
  color: var(--zr-muted);
  margin-top: 8px;
}

.zr-store {
  border: 1px solid var(--zr-line-strong);
  padding: 16px 18px;
  margin: 22px 0;
  background: var(--zr-raised);
}

.zr-store__list {
  display: grid;
  gap: 6px 20px;
  margin: 0 0 12px;
}

.zr-store__row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  border-bottom: 1px dashed var(--zr-line-strong);
  padding-bottom: 6px;
}

.zr-store__row dt {
  font-family: var(--zr-mono);
  font-size: 0.8rem;
  color: var(--zr-muted);
}

.zr-store__row dd {
  margin: 0;
  text-align: right;
  font-size: 0.92rem;
}

.zr-store__link {
  font-family: var(--zr-mono);
  font-size: 0.85rem;
  display: inline-block;
  padding: 12px 0;
}

.zr-method {
  counter-reset: zr-step;
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.zr-method li {
  counter-increment: zr-step;
  position: relative;
  padding-left: 48px;
}

.zr-method li::before {
  content: "[" counter(zr-step, decimal-leading-zero) "]";
  position: absolute;
  left: 0;
  top: 1px;
  font-family: var(--zr-mono);
  font-size: 0.85rem;
  color: var(--zr-accent-deep);
}

.zr-feat {
  display: grid;
  gap: 16px;
  margin-top: 18px;
}

.zr-feat__main {
  border: 1px solid var(--zr-line-strong);
  padding: 20px;
  background: var(--zr-raised);
}

.zr-feat__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.zr-feat__list li {
  border-top: 1px solid var(--zr-line);
  padding-top: 12px;
}

.zr-howto {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 22px;
}

.zr-howto__step {
  display: grid;
  gap: 12px;
  border-top: 1px solid var(--zr-line);
  padding-top: 16px;
}

.zr-howto__step figure {
  margin: 0;
}

.zr-worked {
  border: 1px solid var(--zr-line-strong);
  background: #111315;
  color: #e6e8ea;
  margin: 18px 0;
}

.zr-worked__title {
  font-family: var(--zr-mono);
  font-size: 0.8rem;
  color: #9ea6ad;
  padding: 10px 14px;
  border-bottom: 1px solid #2a2e33;
  margin: 0;
}

.zr-worked pre {
  margin: 0;
  padding: 14px;
  overflow-x: auto;
  font-family: var(--zr-mono);
  font-size: 0.86rem;
  line-height: 1.6;
  white-space: pre;
}

.zr-diagram {
  margin: 20px 0;
  border: 1px solid var(--zr-line-strong);
  background: var(--zr-bg);
  padding: 12px;
}

.zr-diagram svg {
  display: block;
  width: 100%;
  height: auto;
}

.zr-diagram figcaption {
  font-family: var(--zr-mono);
  font-size: 0.78rem;
  color: var(--zr-muted);
  margin-top: 8px;
}

.zr-gloss {
  display: grid;
  gap: 0 28px;
  margin: 18px 0 0;
}

.zr-gloss__item {
  border-top: 1px solid var(--zr-line);
  padding: 12px 0;
}

.zr-gloss__item dt {
  font-family: var(--zr-mono);
  color: var(--zr-accent-deep);
  margin-bottom: 4px;
}

.zr-gloss__item dd {
  margin: 0;
}

.zr-nope {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
}

.zr-nope li {
  position: relative;
  padding: 10px 0 10px 34px;
  border-top: 1px solid var(--zr-line);
}

.zr-nope li::before {
  content: "[x]";
  position: absolute;
  left: 0;
  top: 11px;
  font-family: var(--zr-mono);
  font-size: 0.82rem;
  color: var(--zr-muted);
}

.zr-gallery {
  display: grid;
  gap: 16px;
  margin-top: 18px;
}

.zr-gallery figure {
  margin: 0;
}

.zr-gallery img {
  border: 1px solid var(--zr-line-strong);
}

.zr-gallery figcaption {
  font-size: 0.9rem;
  color: var(--zr-muted);
  margin-top: 8px;
}

.zr-myth {
  display: grid;
  gap: 14px;
  margin-top: 18px;
}

.zr-myth__pair {
  border: 1px solid var(--zr-line-strong);
}

.zr-myth__said,
.zr-myth__real {
  padding: 12px 16px;
  margin: 0;
}

.zr-myth__said {
  background: var(--zr-raised);
  color: var(--zr-muted);
}

.zr-myth__real {
  border-top: 1px solid var(--zr-line);
}

.zr-myth__src {
  display: block;
  font-family: var(--zr-mono);
  font-size: 0.76rem;
  color: var(--zr-muted);
  margin-top: 6px;
}

.zr-calc {
  display: grid;
  gap: 12px;
  margin: 18px 0 0;
}

.zr-calc__cell {
  border: 1px solid var(--zr-line-strong);
  padding: 14px 16px;
}

.zr-calc__cell dt {
  font-family: var(--zr-mono);
  font-size: 0.8rem;
  color: var(--zr-muted);
}

.zr-calc__cell dd {
  margin: 4px 0 0;
  font-family: var(--zr-mono);
  font-size: 1.25rem;
  color: var(--zr-ink);
}

.zr-calc__cell small {
  display: block;
  font-family: var(--zr-sans);
  font-size: 0.86rem;
  color: var(--zr-muted);
}

.zr-slip {
  counter-reset: zr-slip;
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.zr-slip li {
  counter-increment: zr-slip;
  border-left: 2px solid var(--zr-line-strong);
  padding: 2px 0 2px 16px;
}

.zr-slip li::before {
  content: "errore " counter(zr-slip);
  display: block;
  font-family: var(--zr-mono);
  font-size: 0.78rem;
  color: var(--zr-muted);
}

.zr-faq {
  margin-top: 16px;
  border-top: 1px solid var(--zr-line-strong);
}

.zr-faq details {
  border-bottom: 1px solid var(--zr-line-strong);
}

.zr-faq summary {
  cursor: pointer;
  padding: 14px 0;
  font-family: var(--zr-mono);
  font-size: 0.95rem;
  list-style: none;
  min-height: 44px;
}

.zr-faq summary::-webkit-details-marker {
  display: none;
}

.zr-faq summary::before {
  content: "+ ";
  color: var(--zr-accent-deep);
}

.zr-faq details[open] summary::before {
  content: "- ";
}

.zr-faq__a {
  padding-bottom: 12px;
}

.zr-cta {
  margin-top: 40px;
  margin-bottom: 50px;
  border: 1px solid var(--zr-ink);
  padding: 30px 24px;
}

.zr-cta h2 {
  max-width: 26ch;
}

.zr-cta__note {
  font-family: var(--zr-mono);
  font-size: 0.82rem;
  color: var(--zr-muted);
  margin-top: 14px;
  margin-bottom: 0;
}

.zr-legal {
  padding-top: 20px;
  padding-bottom: 40px;
}

.zr-legal h2 {
  font-size: 1.15rem;
  margin-top: 26px;
}

.zr-legal ul {
  padding-left: 20px;
}

.zr-foot {
  border-top: 1px solid var(--zr-line-strong);
  background: var(--zr-raised);
  padding-top: 34px;
  padding-bottom: 20px;
  font-size: 0.93rem;
}

.zr-foot__grid {
  display: grid;
  gap: 24px;
}

.zr-foot h3 {
  font-size: 0.9rem;
  color: var(--zr-muted);
}

.zr-foot p {
  margin-bottom: 6px;
}

.zr-foot__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.zr-foot__list a {
  display: inline-block;
  padding: 12px 0;
  min-height: 44px;
}

.zr-foot__sign {
  font-family: var(--zr-mono);
  font-size: 0.78rem;
  color: var(--zr-muted);
  border-top: 1px solid var(--zr-line);
  margin-top: 22px;
  padding-top: 14px;
}

.zr-bar {
  position: fixed;
  left: 12px;
  right: 12px;
  bottom: 12px;
  z-index: 30;
  background: var(--zr-ink);
  color: #eceee9;
  padding: 16px;
  max-width: 560px;
  border: 1px solid #33373c;
}

.zr-bar[hidden] {
  display: none;
}

.zr-bar__txt {
  font-size: 0.9rem;
}

.zr-bar__txt a {
  color: #8fe0d6;
}

.zr-bar__row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.zr-bar__row .zr-btn {
  flex: 1 1 auto;
}

.zr-bar .zr-btn--ghost {
  color: #eceee9;
  border-color: #6a7076;
}

.zr-bar .zr-btn--ghost:hover {
  background: #26292d;
  color: #ffffff;
}

.zr-js .zr-rise {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 420ms ease, transform 420ms ease;
}

.zr-js .zr-rise.is-in {
  opacity: 1;
  transform: none;
}

@media (min-width: 560px) {
  .zr-bar__row .zr-btn {
    flex: 0 0 auto;
  }

  .zr-store__list {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 760px) {
  .zr-cards {
    grid-template-columns: repeat(3, 1fr);
  }

  .zr-cards--two {
    grid-template-columns: repeat(2, 1fr);
  }

  .zr-bento {
    grid-template-columns: repeat(4, 1fr);
  }

  .zr-tile--big {
    grid-column: span 2;
    grid-row: span 2;
  }

  .zr-tile--wide {
    grid-column: span 2;
  }

  .zr-gloss {
    grid-template-columns: 1fr 1fr;
  }

  .zr-gallery {
    grid-template-columns: repeat(3, 1fr);
  }

  .zr-gallery--two {
    grid-template-columns: 1fr 1fr;
  }

  .zr-myth {
    grid-template-columns: 1fr 1fr;
  }

  .zr-calc {
    grid-template-columns: repeat(3, 1fr);
  }

  .zr-compare__notes {
    grid-template-columns: 1fr 1fr;
  }

  .zr-howto__step {
    grid-template-columns: 1fr 260px;
    align-items: start;
  }

  .zr-foot__grid {
    grid-template-columns: 1.3fr 1fr 1fr;
  }

  .zr-feat {
    grid-template-columns: 1.2fr 1fr;
    align-items: start;
  }
}

@media (min-width: 900px) {
  .zr-hero__grid {
    grid-template-columns: 1.15fr 1fr;
    align-items: center;
  }

  .zr-zig {
    grid-template-columns: 1fr 400px;
    gap: 40px;
  }

  .zr-zig--flip .zr-zig__media {
    order: -1;
  }

  .zr-zig--flip {
    grid-template-columns: 400px 1fr;
  }

  .zr-offset {
    grid-template-columns: repeat(12, 1fr);
  }

  .zr-offset__block--a {
    grid-column: 2 / 10;
  }

  .zr-offset__block--b {
    grid-column: 1 / 8;
  }

  .zr-offset__block--c {
    grid-column: 5 / 13;
  }

  .zr-offset__block--d {
    grid-column: 3 / 12;
  }
}

@media (min-width: 1000px) {
  .zr-split--pinned {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: start;
  }

  .zr-split--pinned .zr-split__side {
    position: sticky;
    top: 20px;
    padding-top: 40px;
  }

  .zr-split--pinned .zr-split__body {
    padding-top: 26px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .zr-js .zr-rise {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .zr-btn {
    transition: none;
  }
}