:root {
  color-scheme: light dark;
  --page: light-dark(#f6f7f9, #0c1118);
  --surface: light-dark(#ffffff, #131a24);
  --surface-hover: light-dark(#f3f5f8, #182231);
  --line: light-dark(#d9dee7, #273344);
  --line-soft: light-dark(#e8ebf0, #1e2937);
  --line-strong: light-dark(#adb8c7, #405069);
  --text: light-dark(#1c222b, #eef2f7);
  --text-secondary: light-dark(#4f5b6b, #aab6c6);
  --text-muted: light-dark(#6d7887, #7e8b9f);
  --brand: light-dark(#0f6cbd, #4f8fe7);
  --brand-hover: light-dark(#115ea3, #62a0ef);
  --brand-soft: light-dark(#e7f2fb, #172a43);
  --success: light-dark(#107c41, #54c68f);
  --header: light-dark(rgba(246, 247, 249, 0.9), rgba(12, 17, 24, 0.9));
  --image-canvas: #090d13;
  --focus: light-dark(#0f6cbd, #8ab6f2);
  --shadow: light-dark(rgba(25, 39, 58, 0.15), rgba(0, 0, 0, 0.28));
  --lightbox: light-dark(rgba(255, 255, 255, 0.98), rgba(10, 15, 22, 0.98));
  --content: 1120px;
}

:root[data-theme="light"] {
  color-scheme: light;
}

:root[data-theme="dark"] {
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 76px;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--page);
  font-family: "Segoe UI Variable", "Segoe UI", "Microsoft YaHei UI", "PingFang SC", system-ui, sans-serif;
  font-size: 15px;
  line-height: 1.55;
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
}

svg {
  display: block;
}

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}

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

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 8px;
  left: 8px;
  padding: 8px 12px;
  border-radius: 6px;
  color: var(--surface);
  background: var(--text);
  transform: translateY(-150%);
}

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

.section,
.site-header {
  width: min(var(--content), calc(100% - 48px));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  z-index: 100;
  top: 0;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  min-height: 64px;
}

.site-header::before {
  content: "";
  position: fixed;
  z-index: -1;
  inset: 0 0 auto;
  height: 64px;
  border-bottom: 1px solid transparent;
  background: var(--header);
  backdrop-filter: blur(16px);
  transition: border-color 150ms ease;
}

.site-header.scrolled::before {
  border-color: var(--line-soft);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  width: fit-content;
  font-weight: 650;
  letter-spacing: -0.01em;
}

.brand-mark {
  width: 32px;
  height: 32px;
}

.footer-links a {
  transition: color 150ms ease;
}

.footer-links a:hover {
  color: var(--brand);
}

.header-actions {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 8px;
}

.language-switch {
  display: flex;
  padding: 2px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.language-switch button {
  min-width: 40px;
  padding: 4px 7px;
  border: 0;
  border-radius: 5px;
  color: var(--text-muted);
  background: transparent;
  cursor: pointer;
  font-size: 12px;
}

.language-switch button.active {
  color: var(--brand);
  background: var(--brand-soft);
}

.icon-button,
.gallery-button {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text-secondary);
  background: var(--surface);
  cursor: pointer;
  transition: color 150ms ease, border-color 150ms ease, background 150ms ease;
}

.icon-button:hover,
.gallery-button:hover {
  color: var(--text);
  border-color: var(--line-strong);
  background: var(--surface-hover);
}

.icon-button svg,
.gallery-button svg {
  width: 17px;
  height: 17px;
}

#theme-toggle svg,
.gallery-button svg {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.github-link svg {
  fill: currentColor;
}

.gallery-button:disabled {
  color: var(--text-muted);
  border-color: var(--line-soft);
  background: transparent;
  cursor: default;
  opacity: 0.45;
}

.hero {
  display: grid;
  grid-template-columns: minmax(340px, 0.78fr) minmax(540px, 1.22fr);
  gap: 48px;
  align-items: center;
  padding-top: 44px;
}

.product-label {
  margin: 0 0 12px;
  color: var(--brand);
  font-size: 13px;
  font-weight: 650;
}

.hero h1 {
  max-width: 500px;
  margin: 0;
  font-size: clamp(2.25rem, 3.5vw, 2.9rem);
  font-weight: 660;
  line-height: 1.12;
  letter-spacing: -0.035em;
}

.hero-summary {
  max-width: 500px;
  margin: 18px 0 0;
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 40px;
  padding: 0 16px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 620;
  transition: color 150ms ease, border-color 150ms ease, background 150ms ease;
}

.button svg {
  width: 17px;
  height: 17px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

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

.button-primary:hover {
  background: var(--brand-hover);
}

.button-secondary {
  color: var(--text-secondary);
  border-color: var(--line);
  background: var(--surface);
}

.button-secondary:hover {
  color: var(--text);
  border-color: var(--line-strong);
  background: var(--surface-hover);
}

.documentation-link {
  flex: 0 0 40px;
  width: 40px;
  padding: 0;
}

.documentation-link svg {
  fill: currentColor;
  stroke: none;
}

.hero-meta {
  margin: 14px 0 0;
  color: var(--text-muted);
  font-size: 12px;
}

.product-gallery {
  min-width: 0;
}

.gallery-viewport {
  display: flex;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--image-canvas);
  box-shadow: 0 18px 44px var(--shadow);
  overscroll-behavior-inline: contain;
  scroll-behavior: smooth;
  scroll-snap-type: x mandatory;
  scrollbar-width: none;
}

.gallery-viewport::-webkit-scrollbar {
  display: none;
}

.gallery-slide {
  position: relative;
  flex: 0 0 100%;
  margin: 0;
  scroll-snap-align: start;
}

.screenshot-button {
  display: block;
  width: 100%;
  padding: 0;
  border: 0;
  background: var(--image-canvas);
  cursor: zoom-in;
}

.screenshot-button img {
  display: block;
  width: 100%;
  height: auto;
  transition: filter 160ms ease;
}

.screenshot-button:hover img {
  filter: brightness(1.04);
}

.gallery-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 54px;
  padding-top: 10px;
}

.gallery-caption {
  display: grid;
  min-width: 0;
}

.gallery-caption strong {
  overflow: hidden;
  font-size: 14px;
  font-weight: 620;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.gallery-caption span {
  overflow: hidden;
  color: var(--text-secondary);
  font-size: 13px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.gallery-controls {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 8px;
}

.gallery-count {
  min-width: 46px;
  color: var(--text-muted);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
}

.gallery-count b {
  color: var(--text);
}

.features {
  padding-top: 52px;
}

.section-title {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
}

.section-title h2 {
  margin: 0;
  font-size: 24px;
  font-weight: 650;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.feature {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 14px;
  min-width: 0;
  padding: 18px;
  border: 1px solid var(--line-soft);
  border-radius: 10px;
  background: var(--surface);
}

.feature > svg {
  width: 22px;
  height: 22px;
  margin-top: 1px;
  fill: none;
  stroke: var(--brand);
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.feature h3 {
  margin: 0 0 5px;
  font-size: 15px;
  font-weight: 650;
}

.feature-heading {
  position: relative;
  display: flex;
  align-items: center;
  gap: 7px;
  margin-bottom: 5px;
}

.feature-heading h3 {
  margin: 0;
}

.feature-heading > .info-tip {
  position: static;
}

.feature-heading .info-tooltip {
  left: 0;
  width: min(320px, 100%);
  transform: translateY(4px);
}

.feature-heading .info-tooltip::after {
  display: none;
}

.feature-heading .info-tip:hover .info-tooltip,
.feature-heading .info-tip:focus .info-tooltip {
  transform: translateY(0);
}

.info-tip {
  position: relative;
  display: inline-grid;
  flex: 0 0 auto;
  place-items: center;
  width: 16px;
  height: 16px;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  color: var(--text-muted);
  cursor: help;
  font-size: 11px;
  font-weight: 700;
  line-height: 1;
}

.info-tip:focus-visible {
  outline-offset: 2px;
}

.info-tooltip {
  position: absolute;
  z-index: 20;
  bottom: calc(100% + 10px);
  left: 50%;
  width: min(320px, calc(100vw - 48px));
  padding: 10px 12px;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  color: light-dark(#ffffff, #17202b);
  background: light-dark(#222a35, #e9eef5);
  box-shadow: 0 10px 28px var(--shadow);
  font-size: 12px;
  font-weight: 400;
  line-height: 1.5;
  opacity: 0;
  pointer-events: auto;
  text-align: left;
  transform: translate(-50%, 4px);
  transition: opacity 120ms ease, transform 120ms ease, visibility 120ms ease;
  visibility: hidden;
}

.info-tooltip::after {
  position: absolute;
  top: 100%;
  left: 50%;
  width: 8px;
  height: 8px;
  border-right: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
  background: inherit;
  content: "";
  transform: translate(-50%, -4px) rotate(45deg);
}

.info-tip:hover .info-tooltip,
.info-tip:focus .info-tooltip {
  opacity: 1;
  transform: translate(-50%, 0);
  visibility: visible;
}

.feature p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.5;
}

.requirements {
  padding-top: 40px;
}

.requirement-grid {
  display: grid;
  grid-template-columns: 1.25fr 1fr 0.8fr;
  margin: 0;
  border-block: 1px solid var(--line);
}

.requirement-grid > div {
  min-width: 0;
  padding: 16px 18px;
}

.requirement-grid > div + div {
  border-left: 1px solid var(--line);
}

.requirement-grid dt {
  margin-bottom: 4px;
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 600;
}

.requirement-heading {
  position: relative;
  display: flex;
  align-items: center;
  gap: 5px;
}

.requirement-heading > .info-tip {
  position: static;
  width: 14px;
  height: 14px;
  font-size: 9px;
}

.requirement-heading .info-tooltip {
  left: 0;
  width: min(300px, 100%);
  transform: translateY(4px);
}

.requirement-heading .info-tooltip::after {
  display: none;
}

.requirement-heading .info-tip:hover .info-tooltip,
.requirement-heading .info-tip:focus .info-tooltip {
  transform: translateY(0);
}

.info-tip.tooltip-dismissed .info-tooltip,
.feature-heading .info-tip.tooltip-dismissed .info-tooltip,
.requirement-heading .info-tip.tooltip-dismissed .info-tooltip {
  opacity: 0;
  pointer-events: none;
  visibility: hidden;
}

.requirement-grid dd {
  margin: 0;
  color: var(--text-secondary);
  font-size: 14px;
}

.site-footer {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 24px;
  min-height: 72px;
  margin-top: 32px;
  border-top: 1px solid var(--line-soft);
  color: var(--text-muted);
  font-size: 12px;
}

.footer-copyright a {
  color: var(--text-secondary);
}

.footer-links {
  display: flex;
  justify-content: flex-end;
  gap: 18px;
}

.lightbox {
  width: min(94vw, 1500px);
  max-width: none;
  padding: 54px 68px 24px;
  overflow: visible;
  border: 1px solid var(--line);
  border-radius: 14px;
  color: var(--text);
  background: var(--lightbox);
  box-shadow: 0 32px 90px rgba(0, 0, 0, 0.36);
}

.lightbox::backdrop {
  background: rgba(0, 0, 0, 0.76);
  backdrop-filter: blur(8px);
}

.lightbox figure {
  margin: 0;
}

.lightbox img {
  display: block;
  width: 100%;
  max-height: 78vh;
  object-fit: contain;
  border: 1px solid var(--line);
  border-radius: 8px;
  transition: opacity 120ms ease;
}

.lightbox img.loading {
  opacity: 0;
}

.lightbox figcaption {
  padding-top: 12px;
  color: var(--text-secondary);
  text-align: center;
  font-size: 13px;
}

.lightbox-close,
.lightbox-arrow {
  position: absolute;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text-secondary);
  background: var(--surface);
  cursor: pointer;
}

.lightbox-close {
  top: 9px;
  right: 9px;
}

.lightbox-arrow {
  top: 50%;
  transform: translateY(-50%);
}

.lightbox-prev {
  left: 14px;
}

.lightbox-next {
  right: 14px;
}

.lightbox-close svg,
.lightbox-arrow svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .hero-copy,
  .hero h1,
  .hero-summary {
    max-width: 680px;
  }
}

@media (max-width: 640px) {
  .section,
  .site-header {
    width: min(var(--content), calc(100% - 32px));
  }

  .brand > span {
    display: none;
  }

  .hero {
    padding-top: 36px;
  }

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

  .hero-actions .button-primary {
    flex: 1 1 100%;
  }

  .hero-actions .button-secondary:not(.documentation-link) {
    flex: 1 1 auto;
  }

  .hero-actions .documentation-link {
    flex: 0 0 40px;
  }

  .gallery-caption span {
    display: none;
  }

  .features {
    padding-top: 40px;
  }

  .feature-grid,
  .requirement-grid {
    grid-template-columns: 1fr;
  }

  .requirement-grid > div + div {
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .site-footer {
    grid-template-columns: 1fr;
    padding: 24px 0;
  }

  .footer-links {
    grid-column: 1;
    grid-row: auto;
    justify-content: center;
  }

  .footer-copyright {
    grid-column: 1;
    grid-row: auto;
    text-align: center;
  }

  .lightbox {
    width: 96vw;
    padding: 48px 8px 18px;
  }

  .lightbox-arrow {
    top: auto;
    bottom: 8px;
    transform: none;
  }

  .lightbox figure {
    padding-bottom: 42px;
  }
}

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

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}