:root {
  color-scheme: light;
  --cabinet-ice: #f4f7fb;
  --cabinet-paper: #fff;
  --cabinet-blue-soft: #edf5ff;
  --cabinet-ink: #17212b;
  --cabinet-muted: #55687d;
  --cabinet-line: #dfe7f0;
  --cabinet-action: #1177b5;
  --cabinet-action-hover: #1076b2;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-padding-top: 24px; }
body { margin: 0; background: var(--cabinet-ice); color: var(--cabinet-ink); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-size: 16px; line-height: 1.65; }
a { color: #146f9f; text-underline-offset: 4px; }
a, button, summary { -webkit-tap-highlight-color: transparent; }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 3px solid var(--cabinet-action); outline-offset: 4px; }
button { font: inherit; cursor: pointer; }
h1,h2,h3,p { margin: 0; }
h1,h2,h3 { line-height: 1.2; }
h1 { margin: 8px 0 16px; font-size: clamp(30px, 4.3vw, 44px); letter-spacing: -.035em; font-weight: 750; }
h2 { font-size: 25px; letter-spacing: -.025em; }
h3 { font-size: 18px; line-height: 1.35; }
code { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: .92em; overflow-wrap: anywhere; }
strong { font-weight: 650; }
.skip-link { position: fixed; z-index: 10; top: 8px; left: 8px; padding: 12px; background: white; transform: translateY(-200%); }
.skip-link:focus { transform: translateY(0); }
.help-shell { width: min(100%, 1088px); margin: 0 auto; padding: 24px 32px max(24px, env(safe-area-inset-bottom)); }
.help-shell-compact { max-width: 720px; }
.help-header { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 44px; margin-bottom: 36px; }
.back-link { display: inline-flex; align-items: center; gap: 10px; min-height: 44px; text-decoration: none; font-weight: 650; }
.back-link:hover { text-decoration: underline; }
.help-brand { color: var(--cabinet-action); font-size: 18px; font-weight: 750; }
.page-intro { max-width: 680px; margin-bottom: 28px; }
.page-intro > p { color: var(--cabinet-muted); max-width: 630px; font-size: 18px; line-height: 1.65; }
.section-label { color: #146f9f; font-size: 14px; font-weight: 650; }
.guide-layout { display: grid; grid-template-columns: 320px minmax(0,1fr); gap: 24px; align-items: start; }
.download-card,.guide-card,.service-card { background: var(--cabinet-paper); border: 1px solid var(--cabinet-line); border-radius: 24px; }
.download-card { padding: 24px; position: sticky; top: 24px; }
.download-heading { display: flex; align-items: center; gap: 14px; }
.download-heading h2 { font-size: 21px; letter-spacing: -.025em; }
.download-heading p { color: var(--cabinet-muted); font-size: 12px; margin-top: 4px; }
.flow-mark { position: relative; display: grid; flex-shrink: 0; place-items: center; width: 52px; height: 52px; border-radius: 16px; background: var(--cabinet-blue-soft); color: var(--cabinet-action); font-size: 31px; font-weight: 750; line-height: 1; }
.flow-mark > span { position: absolute; right: 9px; bottom: 9px; font-size: 10px; }
.platform-note { margin: 24px 0 14px; font-size: 14px; font-weight: 600; }
.action-button { display: flex; align-items: center; justify-content: center; gap: 12px; min-height: 54px; padding: 12px 16px; border-radius: 14px; background: var(--cabinet-action); color: white; font-size: 16px; font-weight: 650; text-decoration: none; text-align: center; line-height: 1.35; }
.action-button:hover { background: var(--cabinet-action-hover); }
.action-button > span { font-size: 22px; }
.download-meta { margin-top: 10px; font-size: 12px; text-align: center; color: var(--cabinet-muted); }
.instruction-link { display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-top: 16px; min-height: 44px; text-decoration: none; font-weight: 600; }
.instruction-link:hover { text-decoration: underline; }
.download-caution { margin-top: 18px; padding-top: 18px; border-top: 1px solid var(--cabinet-line); font-size: 13px; color: var(--cabinet-muted); line-height: 1.65; }
.guide-content { min-width: 0; display: grid; gap: 24px; }
.guide-card { padding: 28px; }
.installation h2 { margin-top: 8px; }
.steps { list-style: none; counter-reset: step; padding: 0; margin: 28px 0 0; }
.steps > li { counter-increment: step; display: grid; grid-template-columns: 32px minmax(0,1fr); gap: 16px; padding: 24px 0; border-top: 1px solid var(--cabinet-line); }
.steps > li:first-child { padding-top: 0; border-top: 0; }
.steps > li:last-child { padding-bottom: 0; }
.steps > li::before { content: counter(step); width: 32px; height: 32px; display: grid; place-items: center; border-radius: 50%; background: var(--cabinet-blue-soft); color: #146f9f; font-weight: 700; font-size: 14px; }
.step-content { padding-top: 3px; min-width: 0; }
.step-content p { margin-top: 10px; color: var(--cabinet-muted); font-size: 15px; }
.step-content p strong { color: var(--cabinet-ink); }
.step-content .step-tip { padding-left: 12px; border-left: 2px solid #c8e3f5; font-size: 13px; }
.copy-address { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px; margin-top: 14px; padding: 10px 12px; background: var(--cabinet-ice); border: 1px solid var(--cabinet-line); border-radius: 12px; }
.copy-address code { font-size: 13px; user-select: all; }
.copy-address button { border: 0; background: var(--cabinet-blue-soft); color: #146f9f; padding: 10px; border-radius: 8px; font-size: 12px; font-weight: 650; min-height: 40px; }
.copy-address button:hover { background: #dceefe; }
.copy-status:empty { display: none; }
.step-content .copy-status { font-size: 12px; color: #146f9f; }
.troubleshooting h2 { margin-bottom: 20px; }
details { border-top: 1px solid var(--cabinet-line); }
summary { position: relative; padding: 18px 24px 18px 0; list-style: none; font-size: 15px; font-weight: 600; cursor: pointer; line-height: 1.5; }
summary::-webkit-details-marker { display: none; }
summary::after { content: '+'; position: absolute; right: 0; top: 15px; color: var(--cabinet-action); font-size: 24px; font-weight: 400; }
details[open] > summary::after { content: '−'; }
details p { padding-bottom: 16px; color: var(--cabinet-muted); font-size: 14px; }
.secondary-button { display: flex; justify-content: center; align-items: center; gap: 12px; padding: 12px 16px; margin-top: 16px; min-height: 48px; border-radius: 12px; background: var(--cabinet-blue-soft); font-size: 15px; font-weight: 650; text-decoration: none; }
.secondary-button:hover { background: #dceefe; }
.limits-note { padding: 0 8px; color: var(--cabinet-muted); font-size: 13px; }
.limits-note h2 { margin-bottom: 10px; color: var(--cabinet-ink); font-size: 16px; }
.limits-note p + p { margin-top: 10px; }
.help-footer { display: flex; justify-content: center; flex-wrap: wrap; gap: 16px; padding-top: 40px; color: var(--cabinet-muted); font-size: 14px; }
.help-footer a { display: inline-flex; align-items: center; min-height: 44px; }
.service-card { display: flex; align-items: flex-start; gap: 20px; padding: 28px; text-decoration: none; }
.service-card:hover { border-color: #a6cee6; }
.service-card .flow-mark { width: 60px; height: 60px; }
.service-card-copy { display: grid; gap: 12px; min-width: 0; }
.service-card-copy > strong { color: var(--cabinet-ink); font-size: 24px; letter-spacing: -.025em; line-height: 1.3; }
.service-card-copy > span { color: var(--cabinet-muted); font-size: 15px; }
.service-card-copy .service-card-action { color: #146f9f; font-weight: 650; margin-top: 6px; }
.support-note { margin-top: 24px; padding: 0 4px; color: var(--cabinet-muted); font-size: 14px; }
.support-note a { display: inline-block; padding: 8px 0; }
@media (max-width: 800px) {
  .help-shell { max-width: 580px; padding: 16px 16px max(24px, env(safe-area-inset-bottom)); }
  .help-header { margin-bottom: 24px; }
  .page-intro > p { font-size: 16px; }
  .guide-layout { grid-template-columns: minmax(0,1fr); gap: 20px; }
  .download-card { position: static; padding: 22px; }
  .download-heading p { font-size: 13px; }
  .platform-note { margin-top: 20px; }
  .download-caution { margin-top: 12px; padding-top: 14px; }
  .guide-content { gap: 20px; }
  .guide-card { padding: 22px; }
  .steps > li { gap: 12px; }
  .service-card { padding: 24px 20px; gap: 16px; }
}
@media (max-width: 360px) {
  .help-shell { padding-left: 12px; padding-right: 12px; }
  .guide-card { padding: 20px 16px; }
  .steps > li { grid-template-columns: 26px minmax(0,1fr); gap: 10px; }
  .steps > li::before { width: 26px; height: 26px; }
  .step-content { padding-top: 0; }
  .service-card { padding: 20px 16px; gap: 12px; }
  .service-card .flow-mark { width: 44px; height: 44px; font-size: 26px; }
}