/* 入夜 · the opening shown every time the site opens (2026-10-11, DEV-20261011-01).
   Turn off: localStorage 'night-isle-splash' = 'off', or open the page with ?splash=off.
   Remove: this stylesheet link, the splash import in web/js/entry.js, and web/js/splash.js. */
.yx-splash {
  --sp-display: "Yashima Mincho", "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  --sp-kana: "Yashima Kana", "Yu Mincho", "Hiragino Mincho ProN", "Noto Serif JP", serif;
  --sp-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", serif;
  --sp-ease: cubic-bezier(.22,.8,.24,1);
  --sp-slow: cubic-bezier(.16,1,.3,1);
  --ink: #f1ece2; --soft: #c9cfdc; --faint: #8e98b0; --accent: #cdbde8; --glow: #f2dfae;
  --rule: rgba(226,214,180,.22);
  --bg: url("/static/images/moonlit-shore.webp");
  --veil: linear-gradient(180deg, rgba(6,10,26,.62) 0%, rgba(8,12,30,.30) 38%, rgba(6,9,24,.55) 68%, rgba(4,6,18,.92) 100%);
  --sheen: linear-gradient(100deg, transparent 35%, rgba(255,240,200,.95) 50%, transparent 65%);
  position: fixed; inset: 0; z-index: 9000; overflow: hidden; isolation: isolate; background: #000; color: var(--ink);
  font-family: var(--sp-serif); text-align: center;
}
:root[data-theme="soft-anime"] .yx-splash {
  --ink: #4a3850; --soft: #6d5a72; --faint: #94808f; --accent: #c86a88; --glow: #f0a3b8;
  --rule: rgba(160,96,126,.24);
  --bg: url("/static/images/sakura-dusk.webp");
  --veil: linear-gradient(180deg, rgba(255,236,240,.18) 0%, rgba(255,240,244,.10) 35%, rgba(252,236,242,.55) 70%, rgba(250,234,240,.94) 100%);
  --sheen: linear-gradient(100deg, transparent 35%, rgba(255,255,255,.95) 50%, transparent 65%);
}
.yx-splash * { box-sizing: border-box; }
.yx-splash button { font: inherit; color: inherit; }
.yx-splash .sp-layer { position: absolute; inset: 0; pointer-events: none; }
.yx-splash .sp-photo { inset: -6%; background: var(--veil), var(--bg) center 40% / cover; opacity: 0; transform: scale(1.14);
  animation: sp-photo 4.2s 1.1s var(--sp-slow) forwards, sp-breathe 26s ease-in-out 5.3s infinite alternate; }
@keyframes sp-photo { 0% { opacity: 0; transform: scale(1.14); filter: brightness(.2) blur(10px); } 60% { opacity: 1; filter: brightness(.8) blur(2px); } 100% { opacity: 1; transform: scale(1.03); filter: none; } }
@keyframes sp-breathe { to { transform: scale(1.07) translate(-.6%, -.4%); } }
.yx-splash canvas.sp-sky { z-index: 1; width: 100%; height: 100%; }
.yx-splash .sp-moon { position: absolute; z-index: 1; top: 9vh; right: 13vw; width: clamp(150px, 19vw, 290px); aspect-ratio: 1; opacity: 0; animation: sp-moon 3.6s 1.8s var(--sp-slow) forwards; }
@keyframes sp-moon { from { opacity: 0; transform: translateY(26px) scale(.96); } to { opacity: 1; transform: none; } }
.yx-splash .sp-moon svg { width: 100%; height: 100%; overflow: visible; }
.yx-splash .sp-bloom { animation: sp-bloom 9s ease-in-out 5s infinite; }
@keyframes sp-bloom { 50% { opacity: .72; } }
.yx-splash .sp-mist { z-index: 2; opacity: 0; animation: sp-fade 4s 2.4s forwards; }
.yx-splash .sp-mist i { position: absolute; left: -30%; width: 160%; height: 26vh; border-radius: 50%; filter: blur(38px); background: radial-gradient(closest-side, rgba(190,200,235,.16), transparent); animation: sp-drift 46s linear infinite alternate; }
.yx-splash .sp-mist i:nth-child(1) { top: 52vh; }
.yx-splash .sp-mist i:nth-child(2) { top: 64vh; animation-duration: 62s; animation-direction: alternate-reverse; opacity: .7; }
@keyframes sp-drift { from { transform: translateX(-6%); } to { transform: translateX(6%); } }
.yx-splash .sp-rays { z-index: 2; opacity: 0; mix-blend-mode: screen; animation: sp-fade 4s 1.8s forwards; }
.yx-splash .sp-rays i { position: absolute; top: -30vh; right: -10vw; width: 120vw; height: 160vh; transform-origin: 85% 0;
  background: repeating-conic-gradient(from 200deg at 85% 0, rgba(255,226,214,0) 0deg, rgba(255,226,214,.20) 2.2deg, rgba(255,226,214,0) 5deg, rgba(255,226,214,0) 9deg);
  -webkit-mask: radial-gradient(70% 70% at 85% 0, #000 0%, transparent 75%); mask: radial-gradient(70% 70% at 85% 0, #000 0%, transparent 75%);
  filter: blur(6px); animation: sp-rays 18s ease-in-out infinite alternate; }
@keyframes sp-rays { from { transform: rotate(-2deg); } to { transform: rotate(2.5deg); } }
.yx-splash .sp-corner { z-index: 2; background: radial-gradient(60vw 50vh at 92% 0%, rgba(255,214,200,.42), transparent 70%); opacity: 0; animation: sp-fade 3s 1.6s forwards; }
:root:not([data-theme="soft-anime"]) .yx-splash :is(.sp-rays, .sp-corner) { display: none; }
:root[data-theme="soft-anime"] .yx-splash :is(.sp-moon, .sp-mist) { display: none; }
.yx-splash .sp-vignette { z-index: 3; background: radial-gradient(120% 90% at 50% 45%, transparent 55%, rgba(0,0,0,.55) 100%); }
:root[data-theme="soft-anime"] .yx-splash .sp-vignette { background: radial-gradient(120% 90% at 50% 45%, transparent 60%, rgba(90,40,60,.22) 100%); }
.yx-splash .sp-grain { z-index: 3; opacity: .06; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E"); }
@keyframes sp-fade { to { opacity: 1; } }

/* ---------------- words */
.yx-splash .sp-stage { position: absolute; inset: 0; z-index: 5; display: grid; place-items: center; padding: 6vh 6vw; overflow: auto; }
.yx-splash .sp-center { width: min(980px, 100%); display: grid; justify-items: center; }
.yx-splash .sp-greet { font-size: 13px; letter-spacing: .6em; padding-left: .6em; color: var(--soft); margin: 0; opacity: 0; animation: sp-greet 2.6s .2s var(--sp-slow) forwards; }
.yx-splash .sp-greet span { opacity: .7; }
@keyframes sp-greet { 0% { opacity: 0; transform: translateY(46px); filter: blur(6px); } 35% { opacity: 1; transform: translateY(46px); filter: none; } 100% { opacity: .85; transform: none; } }
.yx-splash .sp-title { position: relative; display: flex; align-items: flex-start; gap: clamp(14px, 2vw, 26px); margin: 22px 0 0; }
.yx-splash .sp-title h1, .yx-splash .sp-sheen { margin: 0; display: flex; gap: .18em; font-family: var(--sp-display); font-weight: 600; font-size: clamp(64px, 10.5vw, 138px); line-height: 1; letter-spacing: 0; }
.yx-splash .sp-title h1 { color: var(--ink); text-shadow: 0 0 42px color-mix(in srgb, var(--glow) 28%, transparent), 0 2px 30px rgba(0,0,0,.35); }
.yx-splash .sp-title h1 span { display: inline-block; opacity: 0; animation: sp-char 2.2s var(--sp-slow) forwards; }
.yx-splash .sp-title h1 span:nth-child(1) { animation-delay: 1.9s; }
.yx-splash .sp-title h1 span:nth-child(2) { animation-delay: 2.25s; }
@keyframes sp-char { 0% { opacity: 0; filter: blur(18px); transform: translateY(10px) scale(1.06); } 100% { opacity: 1; filter: none; transform: none; } }
.yx-splash .sp-sheen { position: absolute; left: 0; top: 0; pointer-events: none; color: transparent; background: var(--sheen) 0 0 / 300% 100% no-repeat;
  -webkit-background-clip: text; background-clip: text; background-position: 120% 0; animation: sp-sheen 2.6s 3.4s ease-in-out forwards; opacity: .9; }
@keyframes sp-sheen { to { background-position: -20% 0; } }
.yx-splash .sp-kana { writing-mode: vertical-rl; font-family: var(--sp-kana); font-size: 13px; letter-spacing: .62em; color: var(--accent); margin-top: 6px; opacity: 0; animation: sp-fade 1.6s 2.8s forwards; }
.yx-splash .sp-kana::before { content: ''; display: block; width: 1px; height: 26px; margin: 0 auto 12px; background: currentColor; opacity: .6; }
.yx-splash .sp-tag { font-size: clamp(14px, 1.3vw, 17px); letter-spacing: .42em; padding-left: .42em; color: var(--soft); margin: 26px 0 0; opacity: 0; animation: sp-up 1.6s 3.2s var(--sp-slow) forwards; }
@keyframes sp-up { from { opacity: 0; transform: translateY(10px); filter: blur(4px); } to { opacity: 1; transform: none; filter: none; } }
.yx-splash .sp-line { display: flex; align-items: center; gap: 14px; width: min(420px, 70vw); margin: 34px 0 30px; opacity: 0; animation: sp-fade 1.2s 3.6s forwards; }
.yx-splash .sp-line i { flex: 1; height: 1px; background: linear-gradient(90deg, transparent, var(--rule)); transform: scaleX(0); transform-origin: right; animation: sp-grow 1.6s 3.6s var(--sp-slow) forwards; }
.yx-splash .sp-line i:last-child { background: linear-gradient(270deg, transparent, var(--rule)); transform-origin: left; }
.yx-splash .sp-line b { width: 5px; height: 5px; transform: rotate(45deg); background: var(--glow); box-shadow: 0 0 12px var(--glow); }
@keyframes sp-grow { to { transform: scaleX(1); } }

.yx-splash .sp-guide { list-style: none; margin: 0; padding: 22px 0 18px; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); width: min(900px, 100%); opacity: 0; animation: sp-fade 1.4s 3.8s forwards;
  background: linear-gradient(180deg, rgba(14,20,44,.38), rgba(10,14,34,.20)); backdrop-filter: blur(10px); border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); }
:root[data-theme="soft-anime"] .yx-splash .sp-guide { background: linear-gradient(180deg, rgba(255,250,251,.55), rgba(255,244,247,.38)); backdrop-filter: blur(14px) saturate(120%);
  border: 1px solid rgba(200,120,150,.16); border-radius: 4px; box-shadow: 0 24px 60px -36px rgba(120,60,90,.55); }
.yx-splash .sp-guide li { position: relative; padding: 6px clamp(16px, 2.4vw, 34px) 4px; text-align: left; opacity: 0; animation: sp-up 1.4s var(--sp-slow) forwards; }
.yx-splash .sp-guide li + li { border-left: 1px solid var(--rule); }
.yx-splash .sp-guide li:nth-of-type(1) { animation-delay: 4s; }
.yx-splash .sp-guide li:nth-of-type(2) { animation-delay: 4.25s; }
.yx-splash .sp-guide li:nth-of-type(3) { animation-delay: 4.5s; }
.yx-splash .sp-no { position: absolute; right: clamp(10px, 1.6vw, 22px); top: -14px; font-family: var(--sp-display); font-size: 64px; line-height: 1; color: var(--ink); opacity: .07; pointer-events: none; }
.yx-splash .sp-k { display: block; font-family: var(--sp-kana); font-size: 11px; letter-spacing: .42em; color: var(--accent); margin-bottom: 10px; }
.yx-splash .sp-guide b { display: block; font-weight: 600; font-size: 17px; letter-spacing: .2em; margin-bottom: 8px; color: var(--ink); }
.yx-splash .sp-guide p { margin: 0; font-size: 13px; line-height: 1.95; color: var(--soft); }

.yx-splash .sp-actions { display: flex; flex-direction: column; align-items: center; gap: 14px; margin-top: 38px; opacity: 0; animation: sp-up 1.4s 5s var(--sp-slow) forwards; }
.yx-splash .sp-enter { position: relative; display: flex; align-items: center; gap: 18px; cursor: pointer; padding: 15px 40px 15px 46px; border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--glow) 60%, transparent); background: linear-gradient(180deg, rgba(255,255,255,.10), rgba(255,255,255,.02));
  backdrop-filter: blur(10px); color: var(--ink); font-size: 16px; letter-spacing: .5em;
  box-shadow: 0 18px 44px -20px color-mix(in srgb, var(--glow) 70%, transparent); transition: background .5s, transform .5s var(--sp-ease); animation: sp-halo 4.5s 6.4s ease-in-out infinite; }
.yx-splash .sp-enter::after { content: ''; width: 34px; height: 1px; background: currentColor; opacity: .7; transition: width .5s var(--sp-ease); }
.yx-splash .sp-enter:hover { transform: translateY(-2px); background: linear-gradient(180deg, rgba(255,255,255,.18), rgba(255,255,255,.06)); }
.yx-splash .sp-enter:hover::after { width: 52px; }
.yx-splash .sp-enter:focus-visible { outline: 2px solid var(--glow); outline-offset: 4px; }
@keyframes sp-halo { 50% { box-shadow: 0 0 34px -4px color-mix(in srgb, var(--glow) 55%, transparent); } }
:root[data-theme="soft-anime"] .yx-splash .sp-enter { background: linear-gradient(100deg, rgba(228,138,163,.92), rgba(183,154,216,.92)); color: #fffafc; border-color: transparent; }
.yx-splash .sp-later { font-size: 12px; color: var(--faint); display: flex; gap: 7px; align-items: center; cursor: pointer; letter-spacing: .06em; font-family: inherit; }
.yx-splash .sp-later input { accent-color: var(--accent); width: auto; margin: 0; }
.yx-splash .sp-skip { position: absolute; z-index: 6; right: 26px; bottom: 22px; border: 0; background: none; color: var(--faint); font-size: 12px; letter-spacing: .4em; cursor: pointer; opacity: 0; animation: sp-fade 1s .8s forwards; padding: 6px; }
.yx-splash .sp-skip:hover { color: var(--ink); }
/* brief: the opening only; the page enters by itself */
.yx-splash.brief :is(.sp-line, .sp-guide, .sp-actions) { display: none; }
.yx-splash.leaving .sp-stage { animation: sp-leave-words .9s var(--sp-ease) forwards; }
.yx-splash.leaving { animation: sp-leave 1.4s .2s var(--sp-ease) forwards; pointer-events: none; }
@keyframes sp-leave-words { to { opacity: 0; transform: translateY(-14px); filter: blur(6px); } }
@keyframes sp-leave { to { opacity: 0; } }

@media (max-width: 760px) {
  .yx-splash .sp-moon { top: 2.5vh; right: auto; left: 4vw; width: 92px; }
  .yx-splash .sp-stage { padding: 8vh 22px 9vh; align-items: end; }
  .yx-splash.brief .sp-stage { align-items: center; }
  .yx-splash .sp-guide { grid-template-columns: 1fr; }
  .yx-splash .sp-guide li { padding: 12px 20px; }
  .yx-splash .sp-guide li + li { border-left: 0; border-top: 1px solid var(--rule); }
  .yx-splash .sp-no { font-size: 46px; top: 4px; }
  .yx-splash .sp-line { margin: 24px 0 20px; }
  .yx-splash .sp-actions { margin-top: 26px; }
  .yx-splash .sp-tag { letter-spacing: .3em; }
}
@media (prefers-reduced-motion: reduce) {
  .yx-splash, .yx-splash * { animation-duration: .01s !important; animation-delay: 0s !important; animation-iteration-count: 1 !important; }
}

/* The site's global button styles (yashima / tenmondai layers) must not reach the splash. */
:root .yx-splash .sp-enter { border-radius: 999px !important; padding: 15px 40px 15px 46px !important; letter-spacing: .5em !important; font-size: 16px !important;
  border: 1px solid color-mix(in srgb, var(--glow) 60%, transparent) !important; background: linear-gradient(180deg, rgba(255,255,255,.10), rgba(255,255,255,.02)) !important; color: var(--ink) !important; min-height: 0 !important; }
:root .yx-splash .sp-enter:hover { background: linear-gradient(180deg, rgba(255,255,255,.18), rgba(255,255,255,.06)) !important; }
:root[data-theme="soft-anime"] .yx-splash .sp-enter { background: linear-gradient(100deg, rgba(228,138,163,.92), rgba(183,154,216,.92)) !important; color: #fffafc !important; border-color: transparent !important; }
:root .yx-splash .sp-skip { border: 0 !important; background: none !important; box-shadow: none !important; letter-spacing: .4em !important; color: var(--faint) !important; padding: 6px !important; min-height: 0 !important; backdrop-filter: none !important; }
:root .yx-splash .sp-skip:hover { color: var(--ink) !important; }