:root {
  --primary: #0171bb;
  --primary-dark: #004b82;
  --primary-soft: #e9f5fc;
  --ink: #14212b;
  --muted: #5d6b75;
  --surface: #ffffff;
  --surface-alt: #f4f8fb;
  --border: #dce7ef;
  --accent: #df3900;
  --accent-text: #a12a00;
  --success: #19704a;
  --overlay: rgba(10, 27, 40, 0.72);
  --container: 73.75rem;
  --radius-card: 0.5rem;
  --radius-control: 0.375rem;
  --radius-modal: 0.5rem;
  --shadow: 0 14px 36px rgba(0, 75, 130, 0.1);
  --shadow-header: 0 8px 24px rgba(0, 75, 130, 0.08);
  --font-sans: "Microsoft YaHei UI", "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color-scheme: light;
}

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

html {
  min-width: 20rem;
  scroll-behavior: smooth;
  scroll-padding-top: 5.5rem;
}

body {
  min-width: 20rem;
  margin: 0;
  overflow-x: hidden;
  color: var(--ink);
  background: var(--surface);
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body.modal-open {
  overflow: hidden;
}

img,
svg {
  display: block;
  max-width: 100%;
}

img {
  height: auto;
}

button,
input,
select,
textarea {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

a {
  color: var(--primary-dark);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.2em;
}

a:hover {
  color: var(--primary);
}

h1,
h2,
h3,
p,
ul,
ol,
blockquote {
  margin-top: 0;
}

h1,
h2,
h3 {
  color: var(--ink);
  line-height: 1.25;
  letter-spacing: -0.02em;
}

h1 {
  margin-bottom: 1.25rem;
  font-size: 3.25rem;
  font-weight: 750;
}

h2 {
  margin-bottom: 1rem;
  font-size: 2.25rem;
  font-weight: 730;
}

h3 {
  margin-bottom: 0.625rem;
  font-size: 1.25rem;
  font-weight: 700;
}

p:last-child,
ul:last-child,
ol:last-child {
  margin-bottom: 0;
}

[hidden] {
  display: none !important;
}

:focus-visible {
  outline: 0.1875rem solid rgba(1, 113, 187, 0.45);
  outline-offset: 0.1875rem;
}

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 2000;
  transform: translateY(-200%);
  padding: 0.625rem 0.875rem;
  border-radius: var(--radius-control);
  color: #fff;
  background: var(--primary-dark);
  font-weight: 700;
}

.skip-link:focus {
  transform: translateY(0);
}

.container {
  width: min(calc(100% - 3rem), var(--container));
  margin-inline: auto;
}

.narrow {
  width: min(100%, 48rem);
}

.section {
  padding-block: 5rem;
}

.section-alt {
  background: var(--surface-alt);
}

.section-header {
  max-width: 46rem;
  margin-bottom: 2.5rem;
}

.section-header.centered {
  margin-inline: auto;
  text-align: center;
}

.section-header p,
.lead {
  color: var(--muted);
  font-size: 1.125rem;
}

.eyebrow {
  margin-bottom: 0.75rem;
  color: var(--primary-dark);
  font-size: 0.875rem;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.98);
  transition: box-shadow 180ms ease;
}

.site-header.is-scrolled {
  box-shadow: var(--shadow-header);
}

.header-inner {
  min-height: 4.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.brand {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  color: var(--ink);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.2;
  text-decoration: none;
}

.brand:hover {
  color: var(--ink);
}

.brand img {
  width: 2.125rem;
  height: 2.125rem;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-links a {
  position: relative;
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  color: var(--ink);
  font-size: 0.9375rem;
  font-weight: 650;
  text-decoration: none;
}

.nav-links a::after {
  position: absolute;
  right: 0;
  bottom: 0.1rem;
  left: 0;
  height: 0.125rem;
  transform: scaleX(0);
  background: var(--primary);
  content: "";
  transition: transform 180ms ease;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--primary-dark);
}

.nav-links a:hover::after,
.nav-links a[aria-current="page"]::after {
  transform: scaleX(1);
}

.nav-toggle {
  display: none;
  width: 2.75rem;
  height: 2.75rem;
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-control);
  color: var(--ink);
  background: var(--surface);
  cursor: pointer;
}

.nav-toggle .icon-close {
  display: none;
}

.nav-toggle[aria-expanded="true"] .icon-menu {
  display: none;
}

.nav-toggle[aria-expanded="true"] .icon-close {
  display: block;
}

.icon {
  width: 1.5rem;
  height: 1.5rem;
  flex: 0 0 auto;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2;
}

.icon-lg {
  width: 2rem;
  height: 2rem;
}

.button {
  min-height: 3rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.625rem 1.5rem;
  border: 2px solid transparent;
  border-radius: var(--radius-control);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.35;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 180ms ease, border-color 180ms ease, color 180ms ease, transform 180ms ease;
}

.button:hover {
  text-decoration: none;
  transform: translateY(-0.125rem);
}

.button-primary {
  color: #fff;
  background: var(--primary);
  border-color: var(--primary);
}

.button-primary:hover {
  color: #fff;
  background: var(--primary-dark);
  border-color: var(--primary-dark);
}

.button-secondary {
  color: var(--primary-dark);
  background: var(--surface);
  border-color: var(--primary);
}

.button-secondary:hover {
  color: var(--primary-dark);
  background: var(--primary-soft);
}

.button-light {
  color: var(--primary-dark);
  background: #fff;
  border-color: #fff;
}

.button-light:hover {
  color: var(--primary-dark);
  background: var(--primary-soft);
  border-color: var(--primary-soft);
}

.button-small {
  min-height: 2.75rem;
  padding-inline: 1.125rem;
  font-size: 0.9375rem;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.875rem;
}

.justify-center {
  justify-content: center;
}

.spacer-top-sm {
  margin-top: 1.25rem;
}

.spacer-top-md {
  margin-top: 1.5rem;
}

.spacer-top {
  margin-top: 2rem;
}

.centered-icon {
  margin-inline: auto;
  color: var(--primary);
}

.hero {
  padding-block: 5.5rem 6rem;
  overflow: hidden;
  background: var(--surface);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.44fr) minmax(0, 0.56fr);
  align-items: center;
  gap: 4rem;
}

.hero-copy p {
  max-width: 36rem;
  margin-bottom: 2rem;
  color: var(--muted);
  font-size: 1.25rem;
}

.hero-media {
  min-width: 0;
  margin: 0;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  display: grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  background: #fff;
  box-shadow: var(--shadow);
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.trust-strip {
  padding-block: 1.375rem;
  border-block: 1px solid var(--border);
  background: var(--surface-alt);
}

.trust-list {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.trust-list li {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.625rem;
  color: var(--ink);
  font-size: 0.9375rem;
  font-weight: 650;
  text-align: center;
}

.trust-list .icon {
  color: var(--primary);
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  counter-reset: steps;
}

.step {
  position: relative;
  padding: 0 2.25rem;
  text-align: center;
  counter-increment: steps;
}

.step:first-child {
  padding-left: 0;
}

.step:last-child {
  padding-right: 0;
}

.step:not(:last-child)::after {
  position: absolute;
  top: 1.5rem;
  left: calc(50% + 2.5rem);
  width: calc(100% - 5rem);
  height: 1px;
  background: var(--border);
  content: "";
}

.step-number {
  position: relative;
  z-index: 1;
  width: 3rem;
  height: 3rem;
  display: grid;
  place-items: center;
  margin: 0 auto 1.25rem;
  border-radius: 50%;
  color: #fff;
  background: var(--primary);
  font-size: 1.125rem;
  font-weight: 800;
}

.step p,
.feature-item p,
.use-case p,
.feature-block p,
.support-card p {
  color: var(--muted);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem;
}

.feature-item,
.use-case,
.support-card,
.feature-block,
.guide-card {
  min-width: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  background: var(--surface);
}

.feature-item {
  padding: 1.75rem;
}

.feature-icon,
.use-case-icon {
  margin-bottom: 1.25rem;
  color: var(--primary);
}

.use-case-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1.5rem;
}

.use-case {
  padding: 1.5rem;
  border-top: 0.1875rem solid var(--primary);
}

.feedback-note {
  margin-bottom: 1.5rem;
  color: var(--accent-text);
  font-size: 0.9375rem;
  font-weight: 700;
}

.feedback-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-block: 1px solid var(--border);
}

.feedback-item {
  margin: 0;
  padding: 2rem;
}

.feedback-item + .feedback-item {
  border-left: 1px solid var(--border);
}

.feedback-item p {
  margin-bottom: 1rem;
  color: var(--ink);
  font-size: 1.0625rem;
}

.feedback-item footer {
  color: var(--muted);
  font-size: 0.875rem;
}

.split-panel {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  overflow: hidden;
}

.split-panel > div {
  padding: 2.5rem;
}

.split-panel > div + div {
  border-left: 1px solid var(--border);
  background: var(--surface-alt);
}

.check-list,
.plain-list,
.meta-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.check-list li,
.plain-list li {
  position: relative;
  padding-left: 1.75rem;
}

.check-list li + li,
.plain-list li + li {
  margin-top: 0.625rem;
}

.check-list li::before {
  position: absolute;
  top: 0.55rem;
  left: 0;
  width: 0.75rem;
  height: 0.4rem;
  transform: rotate(-45deg);
  border-bottom: 0.125rem solid var(--primary);
  border-left: 0.125rem solid var(--primary);
  content: "";
}

.plain-list li::before {
  position: absolute;
  top: 0.75rem;
  left: 0.25rem;
  width: 0.375rem;
  height: 0.375rem;
  border-radius: 50%;
  background: var(--primary);
  content: "";
}

.cta-band {
  padding-block: 4.5rem;
  color: #fff;
  background: var(--primary-dark);
}

.cta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.cta-band h2,
.cta-band p {
  color: #fff;
}

.cta-band h2 {
  margin-bottom: 0.625rem;
}

.cta-band p {
  margin-bottom: 0;
  opacity: 0.86;
}

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
}

.footer-main {
  display: grid;
  grid-template-columns: minmax(15rem, 1.7fr) repeat(2, minmax(10rem, 1fr));
  gap: 3rem;
  padding-block: 3.5rem;
}

.footer-brand p {
  max-width: 30rem;
  margin-top: 1rem;
  color: var(--muted);
}

.footer-heading {
  margin-bottom: 1rem;
  color: var(--ink);
  font-size: 0.9375rem;
  font-weight: 750;
}

.footer-links {
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-links li + li {
  margin-top: 0.5rem;
}

.footer-links a {
  color: var(--muted);
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

.footer-bottom {
  padding-block: 1.25rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.875rem;
}

.page-hero {
  padding-block: 4.5rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface-alt);
}

.page-hero h1 {
  max-width: 50rem;
  margin-bottom: 1rem;
  font-size: 2.75rem;
}

.page-hero p {
  max-width: 48rem;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 1.125rem;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0 0 1rem;
  padding: 0;
  color: var(--muted);
  font-size: 0.875rem;
  list-style: none;
}

.breadcrumbs li:not(:last-child)::after {
  margin-left: 0.5rem;
  color: #8ca1b0;
  content: "/";
}

.breadcrumbs a {
  color: var(--primary-dark);
}

.content-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem;
}

.feature-block,
.support-card {
  padding: 2rem;
}

.feature-block .icon,
.support-card .icon {
  margin-bottom: 1.25rem;
  color: var(--primary);
}

.feature-block.wide {
  grid-column: 1 / -1;
}

.feature-block-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(16rem, 0.8fr);
  gap: 2.5rem;
  align-items: start;
}

.fact-note,
.info-note,
.warning-note {
  padding: 1rem 1.125rem;
  border-left: 0.25rem solid var(--primary);
  border-radius: 0 var(--radius-control) var(--radius-control) 0;
  color: var(--ink);
  background: var(--primary-soft);
}

.warning-note {
  border-left-color: var(--accent);
  background: #fff4ef;
}

.fact-note strong,
.info-note strong,
.warning-note strong {
  color: inherit;
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.filter-button {
  min-height: 2.75rem;
  padding: 0.5rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-control);
  color: var(--ink);
  background: var(--surface);
  font-weight: 700;
  cursor: pointer;
  transition: color 160ms ease, background-color 160ms ease, border-color 160ms ease;
}

.filter-button:hover {
  border-color: var(--primary);
  color: var(--primary-dark);
}

.filter-button.is-active {
  border-color: var(--primary);
  color: #fff;
  background: var(--primary);
}

.format-groups {
  display: grid;
  gap: 2rem;
}

.format-group {
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  overflow: hidden;
  background: var(--surface);
}

.format-group-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.5rem 1.75rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface-alt);
}

.format-group-header h2 {
  margin: 0;
  font-size: 1.5rem;
}

.format-group-header .icon {
  color: var(--primary);
}

.table-scroll {
  max-width: 100%;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
}

table {
  width: 100%;
  border-collapse: collapse;
  color: var(--ink);
}

th,
td {
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
  vertical-align: top;
}

th {
  width: 11rem;
  color: var(--primary-dark);
  background: #fbfdff;
  font-size: 0.9375rem;
  white-space: nowrap;
}

tr:last-child th,
tr:last-child td {
  border-bottom: 0;
}

.format-list {
  margin: 0;
  color: var(--muted);
  overflow-wrap: anywhere;
}

.format-output {
  color: var(--ink);
  font-weight: 700;
}

.table-hint {
  display: none;
  margin: 0.75rem 1rem 0;
  color: var(--muted);
  font-size: 0.8125rem;
}

.guide-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 18rem;
  gap: 3rem;
  align-items: start;
}

.guide-steps {
  display: grid;
  gap: 1.5rem;
}

.guide-card {
  position: relative;
  display: grid;
  grid-template-columns: 3.5rem minmax(0, 1fr);
  gap: 1.25rem;
  padding: 1.75rem;
}

.guide-index {
  width: 3rem;
  height: 3rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: #fff;
  background: var(--primary);
  font-size: 1.125rem;
  font-weight: 800;
}

.guide-card p {
  color: var(--muted);
}

.guide-sidebar {
  position: sticky;
  top: 6rem;
  padding: 1.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  background: var(--surface-alt);
}

.guide-sidebar h2 {
  font-size: 1.25rem;
}

.guide-sidebar nav a {
  display: block;
  padding-block: 0.4rem;
  color: var(--muted);
  text-decoration: none;
}

.guide-sidebar nav a:hover {
  color: var(--primary-dark);
}

.download-card {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(19rem, 0.8fr);
  gap: 2.5rem;
  padding: 2.5rem;
  border: 1px solid var(--border);
  border-top: 0.25rem solid var(--primary);
  border-radius: var(--radius-card);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.release-label {
  margin-bottom: 0.75rem;
  color: var(--accent-text);
  font-size: 0.875rem;
  font-weight: 800;
  letter-spacing: 0.06em;
}

.download-card h2 {
  margin-bottom: 0.75rem;
}

.download-meta {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin: 1.75rem 0;
}

.download-meta div {
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}

.download-meta dt {
  color: var(--muted);
  font-size: 0.8125rem;
}

.download-meta dd {
  margin: 0.2rem 0 0;
  color: var(--ink);
  font-weight: 700;
}

.download-actions {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  justify-content: center;
  gap: 0.875rem;
  padding: 1.75rem;
  border-radius: var(--radius-card);
  background: var(--surface-alt);
}

.download-actions p {
  margin-bottom: 0.25rem;
  color: var(--muted);
  font-size: 0.875rem;
  text-align: center;
}

.release-list {
  border-top: 1px solid var(--border);
}

.release-entry {
  display: grid;
  grid-template-columns: 8rem minmax(0, 1fr);
  gap: 2rem;
  padding-block: 1.75rem;
  border-bottom: 1px solid var(--border);
}

.release-entry h3 {
  margin-bottom: 0.25rem;
}

.release-entry time,
.release-entry .release-status {
  color: var(--muted);
  font-size: 0.875rem;
}

.faq-list {
  border-top: 1px solid var(--border);
}

.faq-item {
  border-bottom: 1px solid var(--border);
}

.faq-item summary {
  position: relative;
  min-height: 4.75rem;
  display: flex;
  align-items: center;
  padding: 1rem 3.25rem 1rem 0;
  color: var(--ink);
  font-size: 1.0625rem;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
}

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

.faq-item summary::before,
.faq-item summary::after {
  position: absolute;
  right: 0.625rem;
  width: 1rem;
  height: 0.125rem;
  background: var(--primary);
  content: "";
  transition: transform 180ms ease;
}

.faq-item summary::after {
  transform: rotate(90deg);
}

.faq-item[open] summary::after {
  transform: rotate(0);
}

.faq-answer {
  max-width: 52rem;
  padding: 0 3.25rem 1.5rem 0;
  color: var(--muted);
}

.download-modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: grid;
  place-items: center;
  padding: 1.5rem;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  z-index: 1000;
  background: var(--overlay);
}

.download-dialog {
  position: relative;
  z-index: 1001;
  width: min(100%, 38.75rem);
  max-height: min(47.5rem, calc(100dvh - 3rem));
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border-radius: var(--radius-modal);
  background: var(--surface);
  box-shadow: 0 24px 70px rgba(10, 27, 40, 0.3);
}

.modal-header {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

.modal-header h2 {
  margin: 0;
  font-size: 1.5rem;
}

.icon-button {
  width: 2.75rem;
  height: 2.75rem;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-control);
  color: var(--ink);
  background: var(--surface);
  cursor: pointer;
}

.icon-button:hover {
  border-color: var(--primary);
  color: var(--primary-dark);
}

.modal-body {
  min-height: 0;
  overflow-y: auto;
  padding: 1.5rem;
}

.modal-intro {
  margin-bottom: 1.5rem;
  color: var(--muted);
  text-align: center;
}

.download-options {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem;
}

.download-option {
  min-width: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  color: var(--ink);
  text-align: center;
  text-decoration: none;
}

.download-option:hover {
  border-color: var(--primary);
  color: var(--primary-dark);
  background: var(--surface-alt);
}

.qr-placeholder {
  width: 10rem;
  height: 10rem;
  display: grid;
  place-items: center;
  padding: 1rem;
  border-radius: 0.25rem;
  color: #fff;
  font-size: 1rem;
  font-weight: 800;
  line-height: 1.35;
}


.download-option small {
  color: var(--muted);
  font-size: 0.8125rem;
}

.modal-footnote {
  margin: 1.25rem 0 0;
  color: var(--muted);
  font-size: 0.8125rem;
  text-align: center;
}

.error-page {
  min-height: calc(100vh - 4.25rem);
  display: grid;
  place-items: center;
  padding-block: 5rem;
  background: var(--surface-alt);
}

.error-content {
  max-width: 42rem;
  text-align: center;
}

.error-code {
  margin-bottom: 0.75rem;
  color: var(--primary);
  font-size: 5rem;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.05em;
}

.error-content h1 {
  font-size: 2.5rem;
}

.error-content p {
  color: var(--muted);
  font-size: 1.125rem;
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 2rem;
}

.link-grid a {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  color: var(--ink);
  background: var(--surface);
  font-weight: 700;
  text-decoration: none;
}

.link-grid a:hover {
  border-color: var(--primary);
  color: var(--primary-dark);
}

@media (max-width: 56.25rem) {
  h1 {
    font-size: 2.75rem;
  }

  .section {
    padding-block: 4rem;
  }

  .js .nav-toggle {
    display: inline-flex;
  }

  .header-inner {
    gap: 1rem;
  }

  .site-nav {
    flex: 1 1 100%;
    justify-content: flex-end;
    gap: 1rem;
  }

  .nav-links {
    flex-wrap: wrap;
    justify-content: flex-end;
    row-gap: 0.25rem;
  }

  .js .nav-links {
    position: fixed;
    top: 4.25rem;
    right: 0;
    left: 0;
    z-index: 200;
    max-height: calc(100dvh - 4.25rem);
    display: none;
    overflow-y: auto;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 1rem 1.5rem 1.5rem;
    border-bottom: 1px solid var(--border);
    background: var(--surface);
    box-shadow: var(--shadow-header);
  }

  .js .nav-links.is-open {
    display: flex;
  }

  .js .nav-links li,
  .js .nav-links a {
    width: 100%;
  }

  .js .nav-links a {
    min-height: 3rem;
    justify-content: flex-start;
  }

  .js .nav-links a::after {
    bottom: 0;
  }

  .hero {
    padding-block: 4rem;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2.75rem;
  }

  .trust-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .feature-grid,
  .use-case-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .feedback-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .feedback-item:last-child {
    grid-column: 1 / -1;
    border-top: 1px solid var(--border);
    border-left: 0;
  }

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

  .feature-block.wide {
    grid-column: auto;
  }

  .feature-block-inner,
  .download-card {
    grid-template-columns: 1fr;
  }

  .guide-layout {
    grid-template-columns: 1fr;
  }

  .guide-sidebar {
    position: static;
    order: -1;
  }

  .footer-main {
    grid-template-columns: 1.5fr repeat(2, 1fr);
    gap: 2rem;
  }
}

@media (max-width: 45rem) {
  .container {
    width: min(calc(100% - 2rem), var(--container));
  }

  h1,
  .page-hero h1 {
    font-size: 2.25rem;
  }

  h2 {
    font-size: 1.875rem;
  }

  .section {
    padding-block: 3rem;
  }

  .hero {
    padding-block: 3.5rem;
  }

  .hero-copy p {
    font-size: 1.125rem;
  }

  .page-hero {
    padding-block: 3rem;
  }

  .header-inner {
    min-height: 4rem;
  }

  .js .nav-links {
    top: 4rem;
    max-height: calc(100dvh - 4rem);
    padding-inline: 1rem;
  }

  .site-nav > .button {
    display: none;
  }

  .steps,
  .feature-grid,
  .use-case-grid,
  .feedback-grid,
  .split-panel,
  .content-grid,
  .footer-main {
    grid-template-columns: 1fr;
  }

  .step {
    display: grid;
    grid-template-columns: 3rem minmax(0, 1fr);
    gap: 1rem;
    padding: 0 0 2rem;
    text-align: left;
  }

  .step:last-child {
    padding-bottom: 0;
  }

  .step-number {
    margin: 0;
  }

  .step:not(:last-child)::after {
    top: 3rem;
    left: 1.5rem;
    width: 1px;
    height: calc(100% - 3rem);
  }

  .feedback-item + .feedback-item,
  .feedback-item:last-child {
    grid-column: auto;
    border-top: 1px solid var(--border);
    border-left: 0;
  }

  .split-panel > div + div {
    border-top: 1px solid var(--border);
    border-left: 0;
  }

  .cta-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .footer-main {
    gap: 2rem;
  }

  .table-hint {
    display: block;
  }

  .guide-card {
    grid-template-columns: 1fr;
  }

  .guide-index {
    width: 2.75rem;
    height: 2.75rem;
  }

  .release-entry {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

  .download-modal {
    padding: max(1rem, env(safe-area-inset-top)) max(1rem, env(safe-area-inset-right)) max(1rem, env(safe-area-inset-bottom)) max(1rem, env(safe-area-inset-left));
  }

  .download-dialog {
    max-height: calc(100dvh - 2rem);
  }

  .download-options {
    grid-template-columns: 1fr;
  }

  .qr-placeholder {
    width: 9rem;
    height: 9rem;
  }

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

@media (max-width: 30rem) {
  .brand {
    font-size: 1.0625rem;
  }

  .brand img {
    width: 1.875rem;
    height: 1.875rem;
  }

  h1,
  .page-hero h1 {
    font-size: 2rem;
  }

  .button-row {
    flex-direction: column;
  }

  .button-row .button {
    width: 100%;
  }

  .trust-list {
    grid-template-columns: 1fr 1fr;
  }

  .trust-list li:last-child {
    grid-column: 1 / -1;
  }

  .download-card,
  .feature-block,
  .support-card,
  .guide-card,
  .split-panel > div {
    padding: 1.25rem;
  }

  .download-meta {
    grid-template-columns: 1fr;
  }

  .modal-header,
  .modal-body {
    padding-inline: 1rem;
  }

  .modal-header h2 {
    font-size: 1.25rem;
  }

  .error-code {
    font-size: 4rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}