:root {
  color-scheme: light;
  --blue: #0b3d91;
  --light-blue: #eaf2ff;
  --line: #9db8df;
  --ink: #17233b;
  --muted: #596579;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: #f7fbff; color: var(--ink); font-family: "MS PGothic", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif; font-size: 1rem; line-height: 1.75; }
a { color: #0645ad; text-underline-offset: .15em; }
a:hover { color: #0b3d91; }
:focus-visible { outline: 3px solid #b36b00; outline-offset: 3px; }
h1, h2, h3, p, li, a { overflow-wrap: anywhere; }
.page-shell { width: min(940px, calc(100% - 2rem)); margin: 1rem auto 2rem; }
.masthead { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 1rem; padding: 1rem 1.2rem; border: 1px solid var(--line); background: linear-gradient(#fff, var(--light-blue)); }
.lab-brand { color: var(--blue); font-size: 1.35rem; font-weight: 700; text-decoration: none; }
.lab-brand small { display: block; color: var(--muted); font-size: .78rem; font-weight: 400; }
.page-nav { display: flex; flex-wrap: wrap; gap: .5rem 1rem; font-size: .9rem; }
.hero { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, .95fr); align-items: center; gap: 1.5rem; margin: 1rem 0; padding: 1.2rem; border: 1px dotted var(--line); background: #fff; }
.eyebrow { margin: 0 0 .6rem; color: var(--blue); font-size: .78rem; }
.hero h1 { margin: 0; color: var(--blue); font-size: clamp(2rem, 4.6vw, 2.8rem); line-height: 1.3; letter-spacing: -.035em; }
.product-name { display: block; margin-bottom: .55rem; font-size: clamp(1.1rem, 2.4vw, 1.4rem); letter-spacing: 0; }
.hero h1 em { font-style: normal; }
.hero-subtitle { margin: .4rem 0 .9rem; color: var(--blue); font-size: 1.1rem; font-weight: 700; }
.hero-lede, .hero-description { margin: .5rem 0; font-size: .93rem; }
.hero-links { margin: .8rem 0; font-size: .9rem; }
.hero-note, .small { color: var(--muted); font-size: .85rem; }
.hero-note { margin: .6rem 0 0; }
.info-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 1rem; align-items: stretch; }
.panel { min-width: 0; padding: 1rem 1.1rem; border: 1px dotted var(--line); background: #fff; }
.panel h2 { margin: 0 0 .8rem; padding-bottom: .35rem; border-bottom: 1px dotted var(--line); color: var(--blue); font-size: 1.2rem; }
.panel p { margin: .6rem 0; }
.button { display: inline-flex; justify-content: center; align-items: center; min-height: 44px; padding: .65rem 1rem; border: 1px solid var(--blue); border-radius: 2px; font-weight: 700; font-size: .93rem; line-height: 1.45; text-decoration: none; text-align: center; text-wrap: balance; transition: background-color .15s ease; }
.button-primary { background: var(--blue); color: #fff; }
.button-primary:hover { background: #174fa6; color: #fff; }
.button-secondary { background: var(--light-blue); color: var(--blue); }
.button-secondary:hover { background: #dce9ff; }
.submarine-recovery { max-width: 100%; white-space: normal; }
.download-action .button { width: 100%; }
.apk-download-row .button { flex-wrap: wrap; gap: .25rem .6rem; }
.apk-download-row .button > span { white-space: nowrap; }
.apk-version { color: inherit; font-size: .75rem; font-weight: 400; white-space: nowrap; }
.install-step { margin: .9rem 0 .5rem; color: var(--blue); font-size: .95rem; }
.install-step:first-child { margin-top: 0; }
.download-action .submarine-recovery { margin-top: .35rem; }
.steps { margin: 0; padding-left: 1.4rem; }
.steps li { padding: .3rem 0; }
.steps strong { margin-right: .5rem; color: var(--blue); }
.first-run-note { padding: .6rem .75rem; border-left: 2px solid var(--line); background: #f4f8ff; font-size: .9rem; }
.recovery-section { margin-top: 1rem; }
.full-support { margin-top: 1rem; padding: .75rem; border: 1px dotted var(--line); background: #f4f8ff; font-size: .9rem; }
.full-support h3 { margin: 0 0 .6rem; color: var(--blue); font-size: 1rem; }
.recovery-steps { margin: .8rem 0; padding-left: 1.4rem; }
.recovery-steps li { margin: .5rem 0; }
.recovery-steps strong { color: #8a4b00; }
.recovery-help { margin-top: .8rem; padding-top: .7rem; border-top: 1px dashed var(--line); scroll-margin-top: 1rem; }
.recovery-help h3 { margin: 0; color: var(--blue); font-size: 1rem; }
.recovery-help > p, .recovery-details { font-size: .9rem; }
.recovery-details { margin: .7rem 0; padding: .55rem .7rem; border: 1px solid #cbd9ea; background: #f7fbff; }
.recovery-details summary { min-height: 30px; color: #0645ad; cursor: pointer; font-weight: 700; }
.recovery-details[open] summary { margin-bottom: .6rem; }
.report-links { display: flex; flex-wrap: wrap; align-items: center; gap: .7rem 1rem; padding-top: .3rem; }
.page-footer { display: flex; flex-wrap: wrap; justify-content: center; gap: .4rem 1.3rem; margin-top: 1rem; padding: 1rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .85rem; }

/* The original CSS/SVG dive scene is retained as a small ocean window. */
.ocean-scene { position: relative; isolation: isolate; overflow: hidden; width: 100%; height: 500px; border: 1px solid rgba(151, 225, 232, .27); border-radius: 6px; background: radial-gradient(circle at 52% 21%, #255d75 0, #123b54 34%, #082638 74%, #071b2d 100%); box-shadow: 0 32px 70px rgba(0, 5, 18, .28); }
.ocean-scene::before { position: absolute; z-index: 1; inset: 0; background: repeating-linear-gradient(90deg, transparent 0 64px, rgba(187, 240, 241, .035) 65px 66px); content: ""; pointer-events: none; }
.scene-top, .scene-bottom { position: absolute; z-index: 6; right: 24px; left: 24px; display: flex; justify-content: space-between; color: #c4e5e5; font-family: Arial, sans-serif; font-size: .63rem; font-weight: 700; letter-spacing: .13em; }
.scene-top { top: 22px; }
.scene-top span:last-child { color: var(--aqua); }
.scene-bottom { bottom: 21px; }
.scene-bottom span:last-child { font-size: 1rem; line-height: 1; }
.scene-glow { position: absolute; top: 16%; left: 15%; width: 65%; height: 48%; border-radius: 50%; background: radial-gradient(circle, rgba(141, 239, 227, .23), transparent 70%); }
.depth-markers { position: absolute; z-index: 5; top: 91px; right: 24px; display: grid; gap: 123px; padding-right: 12px; border-right: 1px dashed rgba(193, 232, 234, .4); color: rgba(210, 245, 244, .8); font-family: Arial, sans-serif; font-size: .65rem; }
.mini-browser { position: absolute; z-index: 2; top: 20%; left: 12%; width: min(71%, 375px); border: 7px solid #e7f3f4; border-radius: 17px; background: #eff7f5; color: #123047; box-shadow: 0 24px 45px rgba(0, 14, 29, .43); transform: translateY(76px) rotate(2deg); animation: browser-dive 7s cubic-bezier(.22,.66,.28,1) .5s both; }
.browser-toolbar { display: flex; align-items: center; gap: .6rem; height: 42px; padding: 0 .7rem; border-bottom: 1px solid #cddfe1; background: #e8f0f1; }
.toolbar-dots { display: flex; gap: 4px; }
.toolbar-dots i { width: 6px; height: 6px; border-radius: 50%; background: #82a5b2; }
.toolbar-dots i:first-child { background: #ef987e; }
.toolbar-url { overflow: hidden; flex: 1; padding: .24rem .55rem; border-radius: 4px; background: #fff; color: #537589; font-family: Arial, sans-serif; font-size: .62rem; text-overflow: ellipsis; white-space: nowrap; }
.toolbar-more { color: #64889b; font-size: 1.1rem; line-height: 1; }
.browser-screen { display: flex; flex-direction: column; align-items: flex-start; min-height: 228px; padding: 1.2rem 1.3rem; }
.screen-kicker { color: #3e8b9c; font-family: Arial, sans-serif; font-size: .58rem; font-weight: 800; letter-spacing: .13em; }
.browser-screen strong { margin: .85rem 0 1rem; font-size: clamp(.95rem, 1.7vw, 1.18rem); }
.screen-rule { width: 75%; height: 6px; margin-bottom: .5rem; border-radius: 9px; background: #c6d8db; }
.screen-rule.short { width: 52%; }
.screen-preview { width: 100%; height: 65px; margin-top: auto; border-radius: 5px; background: linear-gradient(110deg, #bce7df, #d4eff0 60%, #a3d5de); }
.browser-timer { position: absolute; right: -23px; bottom: -22px; display: flex; flex-direction: column; align-items: center; justify-content: center; width: 94px; height: 94px; border: 5px solid #dcf9f3; border-radius: 50%; background: #0f5169; color: #fff; font-family: Arial, sans-serif; font-size: 1.25rem; font-weight: 800; line-height: 1.2; box-shadow: 0 8px 22px rgba(0, 24, 41, .25); }
.browser-timer small { margin-top: .25rem; color: #c1eee8; font-family: Meiryo, sans-serif; font-size: .61rem; font-weight: 700; }
.water { position: absolute; z-index: 3; inset: 54% 0 0; background: linear-gradient(rgba(11, 98, 127, .77), rgba(2, 29, 54, .96)); }
.wave { position: absolute; right: 0; bottom: 100%; left: 0; width: 100%; height: 34px; color: #0b6280; opacity: .82; }
.water::after { position: absolute; inset: 12px 0 0; background: repeating-linear-gradient(0deg, transparent 0 64px, rgba(165, 232, 233, .07) 65px 66px); content: ""; }
.water-label { position: absolute; z-index: 1; right: 27%; bottom: 63px; color: #a4d9df; font-family: Arial, sans-serif; font-size: .65rem; font-weight: 700; letter-spacing: .14em; }
.water-label b { display: block; color: #d9faf3; font-size: 1rem; letter-spacing: .06em; }
.bubble { position: absolute; z-index: 4; bottom: 7%; border: 1px solid rgba(193, 248, 246, .52); border-radius: 50%; opacity: 0; animation: bubble-rise 5.5s ease-in infinite; }
.bubble-one { left: 21%; width: 10px; height: 10px; animation-delay: 2s; }
.bubble-two { left: 72%; width: 6px; height: 6px; animation-delay: 3.2s; }
.bubble-three { left: 78%; width: 15px; height: 15px; animation-delay: 4.1s; }
@keyframes browser-dive { 0%, 24% { transform: translateY(-32px) rotate(-3deg); } 50% { transform: translateY(10px) rotate(-1deg); } 100% { transform: translateY(76px) rotate(2deg); } }
@keyframes bubble-rise { 0% { transform: translateY(0); opacity: 0; } 20% { opacity: .75; } 90% { opacity: .25; } 100% { transform: translateY(-235px); opacity: 0; } }

.ocean-scene { --aqua: #87efdf; }

@media (max-width: 640px) {
  .page-shell { width: calc(100% - 1rem); margin-top: .5rem; }
  .masthead { padding: .8rem 1rem; gap: .6rem; }
  .page-nav { gap: .5rem .85rem; }
  .hero { grid-template-columns: 1fr; gap: 1rem; padding: 1rem; }
  .hero h1 { font-size: 2.1rem; }
  .hero-lede, .hero-description { font-size: .9rem; }
  .info-grid { grid-template-columns: 1fr; }
  .panel { padding: .85rem 1rem; }
  .ocean-scene { height: 420px; max-width: 440px; margin: 0 auto; }
  .scene-top, .scene-bottom { right: 16px; left: 16px; font-size: .56rem; }
  .scene-top { top: 16px; }
  .scene-bottom { bottom: 16px; }
  .depth-markers { top: 70px; right: 15px; gap: 82px; }
  .mini-browser { top: 19%; left: 9%; width: 74%; }
  .browser-screen { min-height: 183px; padding: .9rem; }
  .browser-screen strong { margin: .5rem 0 .8rem; font-size: .9rem; }
  .screen-preview { height: 48px; }
  .browser-timer { right: -18px; bottom: -16px; width: 73px; height: 73px; font-size: 1rem; }
  .browser-timer small { font-size: .52rem; }
  .water-label { right: 13%; bottom: 45px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .mini-browser { transform: translateY(76px) rotate(2deg); }
  .bubble { display: none; }
}