:root {
  color-scheme: light;
  --bg: #ffffff;
  --text: #101010;
  --muted: #666666;
  --faint: #8a8a8a;
  --soft: #f7f7f7;
  --soft-2: #fbfbfb;
  --line: #e7e7e7;
  --line-strong: #d5d5d5;
  --blue: #0f6fff;
  --blue-dark: #0959d4;
  --shadow: 0 18px 44px rgba(0, 0, 0, 0.08);
  --radius: 8px;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-size: 16px;
  line-height: 1.65;
  letter-spacing: 0;
}

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

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

button {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
  min-height: 58px;
  padding: 0 32px;
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  width: fit-content;
  font-size: 14px;
  font-weight: 650;
}

.brand-mark {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 72px;
  height: 38px;
  overflow: hidden;
  background: transparent;
  border-radius: 0;
}

.brand-mark img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.top-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  color: var(--muted);
  font-size: 14px;
}

.top-nav a:hover,
.toc a:hover {
  color: var(--text);
}

.header-action {
  justify-self: end;
  color: var(--blue);
  font-size: 14px;
  font-weight: 580;
}

.main-grid {
  display: grid;
  grid-template-columns: 248px minmax(0, 1fr);
  gap: 84px;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 32px 96px;
}

.content-column {
  min-width: 0;
}

.hero {
  max-width: 910px;
  padding: 82px 0 70px;
  border-bottom: 1px solid var(--line);
}

.hero-copy h1 {
  max-width: 820px;
  margin: 0;
  font-size: clamp(46px, 6.2vw, 82px);
  line-height: 0.96;
  font-weight: 640;
  letter-spacing: 0;
}

.hero-copy p {
  max-width: 650px;
  margin: 26px 0 0;
  color: #4f4f4f;
  font-size: 19px;
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 17px;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  font-size: 14px;
  font-weight: 620;
  cursor: pointer;
  transition:
    border-color 160ms ease,
    background 160ms ease,
    color 160ms ease,
    transform 160ms ease;
}

.button svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.button:hover {
  transform: translateY(-1px);
}

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

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

.button.secondary {
  color: var(--text);
  background: #ffffff;
}

.button.secondary:hover {
  border-color: #bdbdbd;
  background: #fafafa;
}

.meta-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  max-width: 680px;
  margin: 42px 0 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.meta-strip div {
  padding: 16px 18px 17px 0;
}

.meta-strip div + div {
  padding-left: 18px;
  border-left: 1px solid var(--line);
}

.meta-strip dt {
  margin: 0 0 4px;
  color: var(--muted);
  font-size: 12px;
}

.meta-strip dd {
  margin: 0;
  font-size: 14px;
  font-weight: 620;
}

.hero-shot,
.figure {
  margin: 0;
}

.hero-shot {
  max-width: 860px;
  margin-top: 46px;
}

.image-button {
  display: block;
  width: 100%;
  padding: 0;
  overflow: hidden;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  cursor: zoom-in;
}

.hero-shot .image-button {
  background: #f4f4f4;
  box-shadow: var(--shadow);
}

.image-button img {
  width: 100%;
  height: auto;
}

figcaption {
  margin-top: 10px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.toc {
  position: sticky;
  top: 82px;
  align-self: start;
  min-height: calc(100vh - 104px);
  padding: 82px 0 24px;
  font-size: 13px;
}

.toc p {
  margin: 0 0 16px;
  color: var(--text);
  font-weight: 620;
}

.toc a {
  display: block;
  padding: 8px 0 8px 14px;
  color: #777777;
  border-left: 1px solid var(--line);
  line-height: 1.45;
}

.toc a.active {
  color: var(--text);
  border-left-color: var(--text);
  font-weight: 620;
}

.toc-support {
  margin-top: 28px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--soft-2);
}

.toc-support strong,
.toc-support span,
.toc-support small {
  display: block;
}

.toc-support strong {
  font-size: 13px;
}

.toc-support span {
  margin-top: 6px;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.55;
}

.toc-support small {
  margin-top: 14px;
  color: var(--faint);
  font-size: 11px;
}

.toc-copy {
  width: 100%;
  margin-top: 4px;
  padding: 0;
  color: var(--text);
  background: transparent;
  border: 0;
  cursor: pointer;
  font-size: 22px;
  line-height: 1.1;
  text-align: left;
  font-weight: 650;
}

.guide {
  min-width: 0;
  max-width: 910px;
}

.guide-section {
  position: relative;
  padding: 66px 0 74px;
  border-top: 1px solid var(--line);
}

.hero + .guide .guide-section:first-child {
  border-top: 0;
}

.section-label {
  color: var(--muted);
  font-size: 13px;
  font-weight: 620;
}

.guide-section h2 {
  max-width: 760px;
  margin: 8px 0 0;
  font-size: clamp(30px, 4vw, 50px);
  line-height: 1.12;
  font-weight: 650;
  letter-spacing: 0;
}

.guide-section p {
  max-width: 730px;
  margin: 18px 0 0;
  color: #4c4c4c;
  font-size: 16px;
}

.download-list {
  display: grid;
  gap: 10px;
  margin-top: 26px;
}

.download-list a,
.download-muted {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 24px;
  align-items: baseline;
  min-height: 58px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
}

.download-list.compact a {
  grid-template-columns: 180px minmax(0, 1fr);
}

.download-list a:hover {
  border-color: #bcbcbc;
  background: var(--soft-2);
}

.download-list span,
.download-muted span {
  font-weight: 620;
}

.download-list small,
.download-muted small {
  min-width: 0;
  overflow-wrap: anywhere;
  color: var(--muted);
  font-size: 13px;
}

.download-muted {
  background: var(--soft);
}

.figure {
  margin-top: 30px;
}

.figure .image-button {
  background: var(--soft);
}

.small-figure {
  max-width: 360px;
}

.portrait-figure {
  max-width: 520px;
}

.note {
  padding: 18px 20px;
  border: 1px solid #cddffd;
  border-radius: var(--radius);
  background: #f7faff;
}

.note strong {
  display: block;
  margin-bottom: 4px;
  font-size: 14px;
}

.approval {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 360px);
  gap: 22px;
  align-items: center;
  margin-top: 28px;
}

.approval p {
  margin: 0;
}

.approval-shot {
  background: #ffffff;
}

code {
  padding: 2px 6px;
  background: #eeeeee;
  border-radius: 5px;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.92em;
}

.support-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 220px;
  gap: 34px;
  align-items: center;
  margin-top: 26px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.support-label {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.support-number {
  margin: 4px 0 0;
  color: var(--text);
  font-size: clamp(34px, 6vw, 58px);
  line-height: 1;
  font-weight: 650;
}

.support-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.qr-button {
  cursor: zoom-in;
}

.lightbox {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  padding: 42px;
  background: rgba(0, 0, 0, 0.74);
}

.lightbox[hidden] {
  display: none;
}

.lightbox img {
  max-width: min(94vw, 1440px);
  max-height: 88vh;
  border-radius: var(--radius);
  background: #ffffff;
  box-shadow: 0 20px 80px rgba(0, 0, 0, 0.34);
}

.lightbox-close {
  position: fixed;
  top: 18px;
  right: 22px;
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  color: #ffffff;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 999px;
  cursor: pointer;
  font-size: 28px;
  line-height: 1;
}

.toast {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 60;
  max-width: 280px;
  padding: 11px 14px;
  color: #ffffff;
  background: #111111;
  border-radius: 6px;
  box-shadow: var(--shadow);
  font-size: 14px;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition:
    opacity 160ms ease,
    transform 160ms ease;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 980px) {
  .site-header {
    grid-template-columns: 1fr auto;
    padding: 0 20px;
  }

  .top-nav {
    display: none;
  }

  .main-grid {
    grid-template-columns: 1fr;
    gap: 0;
    padding: 0 20px 76px;
  }

  .hero {
    padding: 60px 0 48px;
  }

  .toc {
    position: relative;
    top: auto;
    display: flex;
    gap: 14px;
    overflow-x: auto;
    min-height: auto;
    padding: 16px 0;
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
  }

  .toc p {
    flex: 0 0 auto;
    margin: 6px 4px 0 0;
  }

  .toc a {
    flex: 0 0 auto;
    padding: 6px 0;
    border-left: 0;
    border-bottom: 1px solid transparent;
  }

  .toc a.active {
    border-bottom-color: var(--text);
  }

  .toc-support {
    display: none;
  }
}

@media (max-width: 700px) {
  .site-header {
    min-height: 58px;
  }

  .header-action {
    display: none;
  }

  .hero-copy h1 {
    font-size: 40px;
  }

  .hero-copy p {
    font-size: 16px;
  }

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

  .meta-strip div + div {
    padding-left: 0;
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .download-list a,
  .download-muted,
  .download-list.compact a {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .guide-section {
    padding: 48px 0 54px;
  }

  .approval,
  .support-grid {
    grid-template-columns: 1fr;
  }

  .support-grid {
    padding: 20px;
  }

  .qr-button {
    max-width: 220px;
  }

  .lightbox {
    padding: 18px;
  }
}

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