.yb-pwa-install-prompt{position:fixed;z-index:999999;left:50%;bottom:calc(88px + env(safe-area-inset-bottom));width:min(620px,calc(100% - 28px));display:grid;grid-template-columns:auto 1fr auto;gap:14px;align-items:center;padding:14px 16px;border:1px solid rgba(255,255,255,.18);border-radius:20px;background:rgba(20,20,20,.97);color:#fff;box-shadow:0 20px 60px rgba(0,0,0,.36);backdrop-filter:blur(18px);transform:translate(-50%,140%);opacity:0;transition:transform .25s ease,opacity .25s ease;font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;cursor:pointer;outline:none}.yb-pwa-install-prompt.is-visible{transform:translate(-50%,0);opacity:1}.yb-pwa-install-mark{width:54px;height:54px;display:grid;place-items:center;border-radius:15px;background:#fff;color:#111;overflow:hidden}.yb-pwa-install-mark img,.yb-pwa-launcher-icon img{display:block;width:100%;height:100%;object-fit:contain}.yb-pwa-install-mark span{font-size:19px;font-weight:900;letter-spacing:-1px}.yb-pwa-install-copy{display:flex;min-width:0;flex-direction:column;gap:4px}.yb-pwa-install-copy strong{font-size:15px;line-height:1.35}.yb-pwa-install-copy span{font-size:13px;line-height:1.5;color:rgba(255,255,255,.78)}.yb-pwa-install-action,.yb-pwa-manual-install{appearance:none;border:0;border-radius:999px;padding:11px 18px;background:#f8b900;color:#111;font-weight:900;cursor:pointer}.yb-pwa-install-close{position:absolute;right:-7px;top:-9px;width:30px;height:30px;border:0;border-radius:50%;background:#fff;color:#111;font-size:19px;line-height:1;cursor:pointer;box-shadow:0 4px 16px rgba(0,0,0,.22)}
.yb-pwa-install-launcher{display:none;position:fixed;z-index:999997;left:50%;bottom:calc(76px + env(safe-area-inset-bottom));width:min(440px,calc(100% - 24px));min-height:64px;grid-template-columns:46px 1fr auto;gap:11px;align-items:center;padding:9px 14px 9px 10px;border:1px solid rgba(0,0,0,.12);border-radius:18px;background:linear-gradient(135deg,#ffb900,#ffd34d);color:#111;box-shadow:0 14px 38px rgba(0,0,0,.28);font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;text-align:start;cursor:pointer;transform:translate(-50%,130%);opacity:0;transition:transform .28s ease,opacity .28s ease,box-shadow .2s ease}.yb-pwa-install-launcher.is-visible{transform:translate(-50%,0);opacity:1}.yb-pwa-install-launcher:active{box-shadow:0 8px 20px rgba(0,0,0,.24)}.yb-pwa-launcher-icon{width:46px;height:46px;display:grid;place-items:center;overflow:hidden;border-radius:13px;background:#fff;box-shadow:0 4px 12px rgba(0,0,0,.12)}.yb-pwa-launcher-icon span{font-weight:900}.yb-pwa-launcher-copy{display:flex;min-width:0;flex-direction:column;gap:2px}.yb-pwa-launcher-copy strong{font-size:14px;line-height:1.3;font-weight:900}.yb-pwa-launcher-copy small{font-size:11.5px;line-height:1.35;font-weight:650;opacity:.78}.yb-pwa-launcher-arrow{font-size:30px;line-height:1;font-weight:800;transform:translateY(-1px)}
@media(max-width:900px){.yb-pwa-install-launcher{display:grid}}@media(max-width:520px){.yb-pwa-install-prompt{grid-template-columns:auto 1fr;padding:13px;bottom:calc(150px + env(safe-area-inset-bottom))}.yb-pwa-install-action{grid-column:1/-1;width:100%}.yb-pwa-install-mark{width:48px;height:48px;border-radius:13px}}@media(prefers-reduced-motion:reduce){.yb-pwa-install-prompt,.yb-pwa-install-launcher{transition:none}}

.yb-pwa-install-prompt:focus-visible{box-shadow:0 0 0 3px #f8b900,0 20px 60px rgba(0,0,0,.36)}.yb-pwa-install-prompt:active{transform:translate(-50%,2px) scale(.995)}.yb-pwa-install-prompt.is-guidance{animation:ybPwaGuidance .65s ease 2;border-color:#f8b900;box-shadow:0 0 0 3px rgba(248,185,0,.25),0 20px 60px rgba(0,0,0,.36)}@keyframes ybPwaGuidance{0%,100%{transform:translate(-50%,0) scale(1)}50%{transform:translate(-50%,-4px) scale(1.015)}}

/* V1.4: unmistakable installation guidance when the browser has no native install prompt (especially iPhone/iPad). */
html.yb-pwa-guide-open,html.yb-pwa-guide-open body{overflow:hidden!important}.yb-pwa-guide-overlay{position:fixed;inset:0;z-index:1000001;display:grid;place-items:center;padding:20px;background:rgba(0,0,0,.72);backdrop-filter:blur(7px);opacity:0;transition:opacity .2s ease;font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}.yb-pwa-guide-overlay.is-visible{opacity:1}.yb-pwa-guide-card{position:relative;width:min(430px,100%);max-height:calc(100dvh - 40px);overflow:auto;padding:22px;border:1px solid rgba(255,255,255,.16);border-radius:24px;background:#171717;color:#fff;box-shadow:0 28px 80px rgba(0,0,0,.5);transform:translateY(16px) scale(.98);transition:transform .22s ease}.yb-pwa-guide-overlay.is-visible .yb-pwa-guide-card{transform:translateY(0) scale(1)}.yb-pwa-guide-close{position:absolute;top:12px;right:12px;width:36px;height:36px;border:0;border-radius:50%;background:#fff;color:#111;font-size:24px;line-height:1;cursor:pointer}.yb-pwa-guide-head{display:flex;align-items:center;gap:13px;padding-right:38px;margin-bottom:16px}.yb-pwa-guide-icon{width:62px;height:62px;flex:0 0 62px;display:grid;place-items:center;overflow:hidden;border-radius:17px;background:#fff;color:#111}.yb-pwa-guide-icon img{display:block;width:100%;height:100%;object-fit:contain}.yb-pwa-guide-icon span{font-size:21px;font-weight:900}.yb-pwa-guide-head>div:last-child{display:flex;min-width:0;flex-direction:column;gap:2px}.yb-pwa-guide-head strong{font-size:21px;line-height:1.25}.yb-pwa-guide-head span{font-size:15px;color:rgba(255,255,255,.76)}.yb-pwa-guide-card>p{margin:0;text-align:center;font-size:15px;line-height:1.55;font-weight:700}.yb-pwa-guide-card>p.yb-pwa-guide-en{margin-top:2px;font-size:12px;font-weight:500;color:rgba(255,255,255,.65)}.yb-pwa-guide-steps{display:grid;gap:10px;margin:19px 0;padding:0;list-style:none}.yb-pwa-guide-steps li{display:grid;grid-template-columns:34px 1fr auto;align-items:center;gap:10px;padding:12px;border-radius:15px;background:rgba(255,255,255,.07);text-align:start}.yb-pwa-guide-steps li>b{width:30px;height:30px;display:grid;place-items:center;border-radius:50%;background:#f8b900;color:#111;font-size:15px}.yb-pwa-guide-steps li>span:not(.yb-pwa-guide-symbol){display:flex;flex-direction:column;gap:2px;font-size:14px;line-height:1.35}.yb-pwa-guide-steps small{font-size:11.5px;color:rgba(255,255,255,.65)}.yb-pwa-guide-symbol{font-size:27px;color:#f8b900}.yb-pwa-guide-done{width:100%;border:0;border-radius:999px;padding:13px 18px;background:#f8b900;color:#111;font-size:15px;font-weight:900;cursor:pointer}@media(max-width:420px){.yb-pwa-guide-card{padding:19px 15px}.yb-pwa-guide-head strong{font-size:18px}.yb-pwa-guide-icon{width:54px;height:54px;flex-basis:54px}.yb-pwa-guide-steps li{grid-template-columns:32px 1fr auto;padding:10px}}@media(prefers-reduced-motion:reduce){.yb-pwa-guide-overlay,.yb-pwa-guide-card{transition:none}}


/* V1.5: illustrated iPhone guidance with 3 screenshots. */
.yb-pwa-guide-gallery{display:grid;gap:12px;margin:16px 0 18px}
.yb-pwa-guide-shot{margin:0;overflow:hidden;border-radius:18px;background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.08)}
.yb-pwa-guide-shot figcaption{display:grid;grid-template-columns:34px 1fr;gap:10px;align-items:start;padding:12px 12px 10px}
.yb-pwa-guide-shot figcaption b{width:30px;height:30px;display:grid;place-items:center;border-radius:50%;background:#f8b900;color:#111;font-size:15px}
.yb-pwa-guide-shot figcaption div{display:flex;flex-direction:column;gap:2px;min-width:0}
.yb-pwa-guide-shot figcaption strong{font-size:14px;line-height:1.35}
.yb-pwa-guide-shot figcaption small{font-size:11.5px;line-height:1.35;color:rgba(255,255,255,.65)}
.yb-pwa-guide-shot img{display:block;width:100%;height:auto;background:#fff}


/* V1.6: never show installation promotion on desktop computers. */
@media (hover:hover) and (pointer:fine) and (min-width:901px){
  .yb-pwa-install-prompt,.yb-pwa-install-launcher,.yb-pwa-guide-overlay{display:none!important}
}