:root {
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Noto Sans JP", sans-serif;
  color: #1f2933;
  background: #f8f9fa;
  font-synthesis: none;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; }
a { color: #1a4568; text-underline-offset: .2em; }
a:hover { color: #0a6790; }
a:focus-visible { outline: 3px solid #317aa1; outline-offset: 3px; border-radius: 3px; }

.site-header {
  border-bottom: 1px solid #d7dce1;
  background: rgba(255,255,255,.96);
}
.header-inner {
  max-width: 1160px;
  min-height: 72px;
  margin: auto;
  padding: 8px 28px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 30px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; color: #1a2b3c; font-size: 1.26rem; font-weight: 800; letter-spacing: -.03em; text-decoration: none; white-space: nowrap; }
.brand small { margin-left: 4px; font-size: .65em; font-weight: 600; letter-spacing: .02em; }
.brand-image { display: block; width: 36px; height: 36px; border: 1px solid #d7dce1; border-radius: 11px; object-fit: cover; }
.site-nav { display: flex; flex-wrap: wrap; gap: 4px; }
.site-nav a { padding: 9px 12px; color: #566472; font-size: .89rem; font-weight: 700; text-decoration: none; border-radius: 9px; white-space: nowrap; }
.site-nav a:hover { color: #1a2b3c; background: #edf2f5; }
.site-nav a[aria-current="page"] { color: #1a2b3c; background: #e5edf2; }

.page-layout { display: grid; grid-template-columns: minmax(0, 1fr) 225px; gap: 52px; max-width: 1160px; margin: 0 auto; padding: 52px 28px 92px; }
.prose { min-width: 0; max-width: 790px; }
.page-eyebrow { margin-bottom: 12px; color: #627384; font-size: .7rem; font-weight: 800; letter-spacing: .14em; }
.prose h1 { margin: 0 0 25px; color: #1a2b3c; font-size: clamp(2rem, 5vw, 3.1rem); line-height: 1.26; letter-spacing: -.045em; }
.prose h2 { scroll-margin-top: 24px; margin: 54px 0 16px; padding-top: 23px; border-top: 1px solid #dbe1e6; color: #1a2b3c; font-size: 1.5rem; line-height: 1.4; letter-spacing: -.035em; }
.prose h3 { scroll-margin-top: 24px; margin: 31px 0 10px; color: #243b50; font-size: 1.08rem; line-height: 1.5; }
.prose p { margin: 0 0 20px; }
.prose h1 + p { font-size: 1.08rem; line-height: 1.9; }
.prose strong { color: #172c3d; }
.prose ul, .prose ol { margin: 8px 0 24px; padding-left: 1.5em; }
.prose li { padding-left: .15em; margin: 8px 0; }
.prose li::marker { color: #4c778f; font-weight: 700; }
.prose h2 + p, .prose h3 + p { margin-top: 0; }
.screenshot { max-width: 330px; margin: 27px auto 38px; }
.screenshot-overview { max-width: 270px; }
.screenshot-overview img[src$="watch-record-selected-screen.png"] { max-width: 240px; margin: auto; }
.screenshot-watch { max-width: 250px; }
.screenshot img { display: block; width: 100%; height: auto; border: 1px solid #d7dce1; border-radius: 25px; box-shadow: 0 15px 42px rgba(26,43,60,.15); }
.watch-swipe-demo { position: relative; width: 100%; aspect-ratio: 416 / 496; overflow: hidden; border: 1px solid #d7dce1; border-radius: 25px; box-shadow: 0 15px 42px rgba(26,43,60,.15); }
.watch-swipe-pages { display: flex; width: 200%; height: 100%; animation: watch-page-swipe 7s ease-in-out infinite; }
.watch-swipe-pages img { flex: 0 0 50%; width: 50%; height: 100%; object-fit: cover; border: 0; border-radius: 0; box-shadow: none; }
.watch-swipe-touch { position: absolute; top: 31%; left: 78%; width: 25px; height: 25px; border: 3px solid white; border-radius: 50%; background: #c56a17; box-shadow: 0 2px 9px rgba(0,0,0,.28); opacity: 0; transform: translate(-50%, -50%); pointer-events: none; animation: watch-touch-swipe 7s linear infinite; }
.watch-record-frame { position: relative; }
.screen-target-ring.watch-record-ring { width: 51%; top: 62%; left: 50%; }
@keyframes watch-page-swipe {
  0%, 12% { transform: translateX(0); }
  30%, 58% { transform: translateX(-50%); }
  76%, 100% { transform: translateX(0); }
}
@keyframes watch-touch-swipe {
  0%, 8% { left: 78%; opacity: 0; }
  10% { left: 78%; opacity: 1; }
  25% { left: 28%; opacity: 1; }
  28%, 100% { left: 22%; opacity: 0; }
}
.screenshot-history-zoom, .screenshot-highlight-zoom, .screenshot-secret-zoom { max-width: 420px; }
.history-zoom-frame, .highlight-zoom-frame, .backup-zoom-frame, .secret-logo-zoom-frame { position: relative; overflow: hidden; border-radius: 18px; }
.history-zoom-frame, .highlight-zoom-frame { aspect-ratio: 21 / 10; }
.history-zoom-frame img, .highlight-zoom-frame img { height: 100%; object-fit: cover; object-position: center 62%; border-radius: 18px; }
.secret-logo-zoom-frame { aspect-ratio: 42 / 17; }
.secret-logo-zoom-frame img { height: 100%; object-fit: cover; object-position: center top; border-radius: 18px; }
.screenshot-backup-zoom { max-width: 420px; }
.backup-zoom-frame { aspect-ratio: 7 / 3; }
.backup-zoom-frame img { height: 100%; object-fit: cover; object-position: center top; border-radius: 18px; }
.screen-target-ring { position: absolute; width: 14%; aspect-ratio: 1; transform: translate(-50%, -50%); border: 3px solid #f59e0b; border-radius: 50%; box-shadow: 0 0 0 4px rgba(255,255,255,.9), 0 3px 12px rgba(0,0,0,.22); pointer-events: none; }
.screen-target-ring::after { content: ''; position: absolute; inset: -7px; border: 3px solid #f59e0b; border-radius: 50%; animation: target-ring-pulse 2s ease-out infinite; }
.history-zoom-ring { left: 90.5%; top: 67.8%; }
.highlight-zoom-ring { left: 9.45%; top: 67.8%; }
.secret-logo-ring { width: 18%; left: 50%; top: 52%; }
.backup-zoom-ring { left: 77.65%; top: 50.2%; }
@keyframes target-ring-pulse {
  0% { transform: scale(.9); opacity: .85; }
  75%, 100% { transform: scale(1.45); opacity: 0; }
}
@media (prefers-reduced-motion: reduce) {
  .screen-target-ring::after { animation: none; opacity: 0; }
  .watch-swipe-pages, .watch-swipe-touch { animation: none; }
}
.screenshot img[src$="tag-selection-screen.png"] { height: 430px; object-fit: cover; object-position: center top; }
.screenshot img[src$="highlight-archive-screen.png"] { height: 360px; object-fit: cover; object-position: center top; }
.screenshot img[src$="secret-history-screen.png"] { height: 250px; object-fit: cover; object-position: center bottom; }
.screenshot img[src$="backup-screen.png"] { height: 500px; object-fit: cover; object-position: center top; }
.screenshot img[src$="app-info-screen.png"] { height: 550px; object-fit: cover; object-position: center center; }
.screenshot figcaption { margin-top: 11px; color: #6f7a86; font-size: .78rem; line-height: 1.6; text-align: center; }
.table-scroll { width: 100%; overflow-x: auto; margin: 20px 0 28px; border: 1px solid #d7dce1; border-radius: 14px; background: white; }
table { width: 100%; border-collapse: collapse; font-size: .92rem; }
th, td { padding: 13px 15px; border-bottom: 1px solid #e6eaee; text-align: left; vertical-align: top; }
th { color: #1a2b3c; background: #eaf0f3; font-weight: 800; }
tbody tr:last-child td { border-bottom: none; }
tbody tr:nth-child(even) { background: #fbfcfd; }

.page-toc { position: sticky; top: 28px; align-self: start; padding: 20px 0 20px 22px; border-left: 1px solid #d7dce1; }
.page-toc p { margin: 0 0 12px; color: #657384; font-size: .75rem; font-weight: 800; letter-spacing: .05em; }
.page-toc nav { display: flex; flex-direction: column; gap: 9px; }
.page-toc a { color: #4c5b69; font-size: .85rem; line-height: 1.45; text-decoration: none; }
.page-toc a:hover { color: #0a6790; text-decoration: underline; }
.mobile-toc { display: none; }
.quick-links { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 42px 0 12px; }
.quick-links a { display: flex; flex-direction: column; min-height: 160px; padding: 19px; border: 1px solid #d7dce1; border-radius: 15px; background: #fff; text-decoration: none; box-shadow: 0 4px 15px rgba(26,43,60,.035); }
.quick-links a:hover { border-color: #8eacba; transform: translateY(-2px); box-shadow: 0 8px 20px rgba(26,43,60,.08); }
.quick-links span { color: #667e8a; font-size: .71rem; font-weight: 800; letter-spacing: .05em; }
.quick-links strong { margin-top: 13px; color: #1a2b3c; font-size: 1.01rem; }
.quick-links small { margin-top: 5px; color: #657384; font-size: .76rem; }
.next-step { display: flex; flex-direction: column; gap: 5px; margin-top: 58px; padding: 26px 29px; border-radius: 17px; background: #eaf0f3; }
.next-step strong { color: #1a2b3c; font-size: 1.08rem; }
.next-step span { color: #516575; font-size: .9rem; }
.next-step a { align-self: flex-start; margin-top: 7px; font-size: .9rem; font-weight: 750; }
.site-footer { display: flex; justify-content: space-between; gap: 16px; max-width: 1160px; margin: auto; padding: 24px 28px 36px; border-top: 1px solid #d7dce1; color: #75818d; font-size: .75rem; }

@media (max-width: 900px) {
  .page-layout { grid-template-columns: minmax(0, 1fr); gap: 0; padding-top: 36px; }
  .page-toc { display: none; }
  .mobile-toc { display: block; margin: 0 0 27px; padding: 14px 18px; border: 1px solid #d7dce1; border-radius: 13px; background: #fff; }
  .mobile-toc summary { color: #1a2b3c; font-size: .87rem; font-weight: 800; cursor: pointer; }
  .mobile-toc nav { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px 14px; margin-top: 13px; }
  .mobile-toc a { font-size: .84rem; text-decoration: none; }
}
@media (max-width: 650px) {
  .header-inner { flex-direction: column; align-items: flex-start; gap: 8px; padding: 13px 18px 8px; }
  .site-nav { width: 100%; flex-wrap: nowrap; overflow-x: auto; gap: 2px; padding-bottom: 3px; }
  .site-nav a { padding: 8px 9px; font-size: .79rem; }
  .page-layout { padding: 31px 20px 65px; }
  .prose h1 { margin-bottom: 20px; }
  .prose h2 { margin-top: 41px; font-size: 1.33rem; }
  .prose h3 { font-size: 1rem; }
  .quick-links { grid-template-columns: 1fr; }
  .quick-links a { min-height: 106px; }
  .next-step { padding: 23px; }
  .mobile-toc nav { grid-template-columns: 1fr; }
  .site-footer { flex-direction: column; padding: 20px; }
}

@media (prefers-color-scheme: dark) {
  :root { color: #e5e7eb; background: #101820; }
  a, a:hover { color: #9ec9e4; }
  .site-header { border-color: #334155; background: #18212b; }
  .brand, .site-nav a[aria-current="page"], .prose h1, .prose h2, .prose strong, .quick-links strong, .next-step strong { color: #e5e7eb; }
  .brand-image, .screenshot img, .watch-swipe-demo { border-color: #334155; }
  .site-nav a { color: #a7b0ba; }
  .site-nav a:hover, .site-nav a[aria-current="page"] { color: #e5e7eb; background: #243244; }
  .prose h2, .page-toc, .site-footer { border-color: #334155; }
  .prose h3 { color: #cbdbe7; }
  .page-eyebrow, .page-toc p, .quick-links span, .quick-links small, .site-footer { color: #a7b0ba; }
  .page-toc a, .next-step span { color: #c0cad2; }
  .quick-links a, .page-toc, .table-scroll { border-color: #334155; background: #18212b; }
  .mobile-toc { border-color: #334155; background: #18212b; }
  .mobile-toc summary { color: #e5e7eb; }
  .quick-links a:hover { border-color: #9db7d0; }
  th { color: #e5e7eb; background: #243244; }
  td, th { border-color: #334155; }
  tbody tr:nth-child(even) { background: #1d2935; }
  .next-step { background: #223041; }
}