:root {
  --ink: #11233d;
  --night: #07182d;
  --river: #0e4b6d;
  --cream: #fff5df;
  --paper: #f8ecd5;
  --amber: #f2ae42;
  --coral: #d8664b;
  --pale: #dceef2;
  --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", STSong, serif;
  --sans: "Noto Sans SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; background: var(--night); }
body { margin: 0; color: var(--ink); background: var(--cream); font-family: var(--sans); line-height: 1.65; }
main { width: min(100%, 680px); margin: 0 auto; overflow: hidden; background: var(--cream); }
.hero { position: relative; min-height: 100svh; display: flex; align-items: flex-end; padding: 8.25rem 1.5rem 3rem; color: #fff8e8; isolation: isolate; }
.hero-art { position: absolute; inset: 0; z-index: -2; background: url("./assets/h5-hero-riverside-night.png") center / cover no-repeat; }
.hero::after { content: ""; position: absolute; inset: 0; z-index: -1; background: linear-gradient(180deg, rgba(2,11,29,.12) 4%, rgba(2,15,35,.1) 40%, rgba(3,13,31,.94) 100%); }
.grain { position: absolute; inset: 0; z-index: -1; pointer-events: none; opacity: .28; background-image: repeating-linear-gradient(104deg, rgba(255,255,255,.03) 0 1px, transparent 1px 5px); mix-blend-mode: soft-light; }
.hero-copy { max-width: 500px; animation: fade-up .8s ease-out both; }
.kicker, .section-index { margin: 0 0 .8rem; color: var(--coral); font-weight: 800; font-size: .72rem; letter-spacing: .16em; text-transform: uppercase; }
.hero .kicker { color: #ffd37b; }
h1, h2, h3, p { overflow-wrap: break-word; }
h1, h2 { margin: 0; font-family: var(--serif); letter-spacing: -.05em; line-height: 1.12; }
h1 { font-size: clamp(3rem, 13vw, 5.7rem); font-weight: 700; }
h1 em { color: #ffcf75; font-style: normal; }
.hero-lead { margin: 1.35rem 0 1.55rem; font-size: 1rem; line-height: 1.85; }
.event-chip { display: inline-flex; flex-wrap: wrap; align-items: center; gap: .5rem .7rem; padding: .65rem .85rem; border: 1px solid rgba(255,255,255,.38); border-radius: 999px; background: rgba(255,255,255,.1); backdrop-filter: blur(8px); font-size: .82rem; }
.event-chip b { color: #ffda8f; font-size: .92rem; }
.scroll-cue { position: absolute; right: 1.5rem; bottom: 1.05rem; display: flex; align-items: center; gap: .45rem; color: #ffe6b5; text-decoration: none; font-size: .72rem; letter-spacing: .08em; }
.scroll-cue i { display: grid; place-items: center; width: 1.7rem; height: 1.7rem; border: 1px solid rgba(255,255,255,.45); border-radius: 50%; font-size: 1rem; font-style: normal; }
.section { padding: 5.25rem 1.5rem; }
h2 { font-size: clamp(2.15rem, 8.5vw, 3.85rem); }
.intro, .games-lead { margin: 1.4rem 0 0; font-size: 1rem; line-height: 1.9; color: rgba(17,35,61,.78); }
.promise-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: .65rem; margin-top: 2.25rem; }
.promise-grid article { position: relative; min-height: 12.5rem; overflow: hidden; border-radius: 1.1rem; background: var(--ink); color: #fff9ea; box-shadow: 0 12px 28px rgba(42,62,73,.14); }
.feature-image { position: absolute; inset: 0; background-image: linear-gradient(180deg, transparent 18%, rgba(4,17,35,.93) 92%), url("./assets/h5-feature-triptych.png"); background-size: cover, 300% 100%; background-repeat: no-repeat; }
.feature-song .feature-image { background-position: center, left center; }
.feature-game .feature-image { background-position: center, center center; }
.feature-gift .feature-image { background-position: center, right center; }
.promise-grid article > div:last-child { position: absolute; inset: auto .85rem .85rem; z-index: 1; }
.promise-grid h3 { margin: 0 0 .1rem; font-size: .98rem; }
.promise-grid p { margin: 0; color: rgba(255,249,234,.8); font-size: .73rem; line-height: 1.5; }
.section-dark { color: #fff6e4; background: var(--night); }
.section-dark .section-index { color: #f4b84f; }
.song-list { margin: 2.3rem 0 0; padding: 0; list-style: none; border-top: 1px solid rgba(255,255,255,.18); }
.song-list li { display: grid; grid-template-columns: 3.1rem 1fr; align-items: baseline; gap: .35rem; padding: 1rem 0; border-bottom: 1px solid rgba(255,255,255,.18); }
.song-list span { color: #f4b84f; font-family: Georgia, serif; font-size: .82rem; letter-spacing: .08em; }
.song-list strong { font-family: var(--serif); font-size: 1.13rem; font-weight: 600; }
.game-list { margin: 2.15rem 0 0; border-top: 1px solid rgba(17,35,61,.16); }
.game-item { border-bottom: 1px solid rgba(17,35,61,.16); }
.game-item summary { display: grid; grid-template-columns: 2.4rem 1fr 1.5rem; gap: .6rem; align-items: center; padding: 1.05rem 0; cursor: pointer; list-style: none; }
.game-item summary::-webkit-details-marker { display: none; }
.game-item summary b { color: var(--coral); font-size: .75rem; letter-spacing: .08em; }
.game-item summary strong { display: block; color: var(--ink); font-size: 1.04rem; }
.game-item summary small { display: block; margin-top: .18rem; color: #697587; font-size: .78rem; line-height: 1.45; }
.game-item summary i { display: grid; place-items: center; width: 1.5rem; height: 1.5rem; border: 1px solid rgba(17,35,61,.25); border-radius: 50%; color: var(--coral); font-size: 1.15rem; font-style: normal; transition: transform .2s ease; }
.game-item[open] summary i { transform: rotate(45deg); }
.game-detail { padding: 0 0 1.25rem; }
.game-detail img { display: block; width: 100%; aspect-ratio: 16 / 9; border-radius: 1rem; object-fit: cover; box-shadow: 0 12px 28px rgba(42,62,73,.13); }
.rules { margin-top: .85rem; padding: .15rem 0 0 .85rem; border-left: 2px solid var(--coral); }
.rules h3 { margin: 0; font-size: .95rem; }
.rules p { margin: .25rem 0 0; color: #596a7d; font-size: .86rem; line-height: 1.8; }
.section-gold { color: var(--ink); background: var(--amber); background-image: radial-gradient(circle at 92% 9%, rgba(255,255,255,.5), transparent 23%), repeating-linear-gradient(135deg, rgba(255,255,255,.12) 0 1px, transparent 1px 7px); }
.section-gold .section-index { color: #80501e; }
.reward-figure { margin: 1.6rem 0; }
.reward-figure img { display: block; width: 100%; aspect-ratio: 16 / 9; border-radius: 1.1rem; object-fit: cover; box-shadow: 0 16px 30px rgba(103,58,18,.2); }
.reward-rules { display: grid; gap: .7rem; margin: 0; padding: 0; list-style: none; }
.reward-rules li { display: grid; grid-template-columns: 2.25rem 1fr; gap: .6rem; align-items: baseline; padding-top: .75rem; border-top: 1px solid rgba(80,49,23,.25); }
.reward-rules b { color: #8e472f; font-size: .74rem; letter-spacing: .05em; }
.reward-rules span { line-height: 1.7; }
.closing { position: relative; min-height: 32rem; display: flex; align-items: flex-end; padding: 5rem 1.5rem 3rem; color: #fff7e6; background: radial-gradient(circle at 80% 13%, rgba(237,160,61,.28), transparent 20rem), linear-gradient(145deg, #07172c, #113d56); isolation: isolate; }
.closing-copy { max-width: 32rem; }
.closing .section-index { color: #ffd37b; }
.closing h2 { color: #fff7e6; }
.closing-copy > p:not(.section-index):not(.small-note) { margin: 1.35rem 0; color: rgba(255,247,230,.88); }
.closing-time { display: inline-flex; flex-wrap: wrap; gap: .4rem .8rem; align-items: center; padding-top: .95rem; border-top: 1px solid rgba(255,255,255,.45); font-size: .82rem; }
.closing-time b { color: #ffd37b; }
.small-note { margin: 1.1rem 0 0; color: rgba(255,247,230,.62); font-size: .75rem; }
@keyframes fade-up { from { opacity: 0; transform: translateY(18px); } to { opacity: 1; transform: translateY(0); } }
@media (min-width: 700px) { .section, .hero, .closing { padding-left: 3.4rem; padding-right: 3.4rem; } .hero { padding-bottom: 4rem; } .scroll-cue { right: 3.4rem; bottom: 1.6rem; } .promise-grid { gap: .85rem; } }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } .hero-copy { animation: none; } }