:root{
  --bg:#fff; --surface:#fff; --mist:#eaf8ff; --ink:#0f2a3d; --ink-soft:#4a6578;
  --bdc:#0f2a3d; --line:#d6ecf8; --th:#7fd6ff; --th-ink:#0f2a3d; --link:#1f7fb0;
  --sky:#7fd6ff; --sky-mid:#4cb8ee; --sky-deep:#2a9fd8; --green:#5fbf6b; --btn-ink:#0f2a3d;
  --hero1:#8fdcff; --hero2:#cdf0ff; --hero3:#fff; --cloud:#fff;
  --h1:#fff; --h1s1:#2a9fd8; --h1s2:#0f2a3d; --header-bg:rgba(255,255,255,.94);
  --bd:3px solid var(--bdc); --sh:4px 4px 0 var(--bdc);
  --pixel:"Press Start 2P","DotGothic16",monospace;
  --font:"DotGothic16","Hiragino Sans","Hiragino Kaku Gothic ProN","Yu Gothic UI","Yu Gothic","Meiryo","Noto Sans JP",system-ui,sans-serif;
  color-scheme:light;
}
:root[data-theme="dark"]{
  --bg:#0b1a26; --surface:#12293b; --mist:#0e2233; --ink:#e8f4fb; --ink-soft:#a3bccd;
  --bdc:#03090f; --line:#2a4d66; --th:#1d4e6c; --th-ink:#e8f4fb; --link:#7fd6ff;
  --hero1:#0f3a57; --hero2:#0d2a40; --hero3:#0b1a26; --cloud:rgba(255,255,255,.14);
  --h1:#eaf9ff; --h1s1:#2a9fd8; --h1s2:#03090f; --header-bg:rgba(11,26,38,.94);
  color-scheme:dark;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#0b1a26; --surface:#12293b; --mist:#0e2233; --ink:#e8f4fb; --ink-soft:#a3bccd;
    --bdc:#03090f; --line:#2a4d66; --th:#1d4e6c; --th-ink:#e8f4fb; --link:#7fd6ff;
    --hero1:#0f3a57; --hero2:#0d2a40; --hero3:#0b1a26; --cloud:rgba(255,255,255,.14);
    --h1:#eaf9ff; --h1s1:#2a9fd8; --h1s2:#03090f; --header-bg:rgba(11,26,38,.94);
    color-scheme:dark;
  }
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:72px}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font);line-height:1.9;font-size:16px;-webkit-text-size-adjust:100%}
a{color:var(--link)}
code{font-family:var(--font);background:var(--surface);border:2px solid var(--bdc);padding:.05em .45em;font-size:.95em;white-space:nowrap}
.wrap{width:min(1040px,100% - 32px);margin-inline:auto}
h1,h2,.brand,.num,.eyebrow,.foot-brand,.addr-row code,th,.theme,.notice-title{font-family:var(--pixel);font-weight:400}

/* header */
.top{position:sticky;top:0;z-index:10;background:var(--header-bg);backdrop-filter:blur(10px);border-bottom:3px solid var(--bdc)}
.top-in{display:flex;align-items:center;gap:12px;height:60px}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none;font-size:.85rem;flex:none}
.nav{display:flex;gap:2px;overflow-x:auto;scrollbar-width:none;margin-left:auto}
.nav::-webkit-scrollbar{display:none}
.nav a{color:var(--ink-soft);text-decoration:none;font-size:.95rem;padding:8px 10px;white-space:nowrap}
.nav a:hover{background:var(--sky);color:#0f2a3d}
.theme{flex:none;cursor:pointer;background:var(--surface);color:var(--ink);border:3px solid var(--bdc);box-shadow:3px 3px 0 var(--bdc);font-size:.58rem;padding:9px 10px;line-height:1}
.theme:active{transform:translate(3px,3px);box-shadow:none}

/* hero */
.hero{background:linear-gradient(180deg,var(--hero1) 0%,var(--hero2) 70%,var(--hero3) 100%);border-bottom:3px solid var(--bdc);position:relative;overflow:hidden}
.hero::before,.hero::after{content:"";position:absolute;background:var(--cloud);box-shadow:0 8px 0 var(--cloud),40px -12px 0 var(--cloud)}
.hero::before{width:120px;height:32px;top:56px;left:6%}
.hero::after{width:160px;height:40px;top:110px;right:6%}
.hero-in{position:relative;padding:72px 0 80px;text-align:center}
.eyebrow{margin:0 0 10px;font-size:.62rem;letter-spacing:.2em;color:var(--sky-deep)}
h1{margin:0;font-size:clamp(2.2rem,10vw,4.6rem);line-height:1.3;letter-spacing:.04em;color:var(--h1);text-shadow:4px 4px 0 var(--h1s1),8px 8px 0 var(--h1s2)}
.lead{margin:22px auto 0;max-width:34em;color:var(--ink-soft);font-size:1.05rem}
.pc{display:none}
@media(min-width:720px){.pc{display:inline}}

.addr{margin:36px auto 0;max-width:460px;background:var(--surface);border:var(--bd);box-shadow:var(--sh);padding:18px;text-align:left}
.addr-label{font-size:.85rem;color:var(--ink-soft)}
.addr-row{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:6px}
.addr-row code{background:none;border:0;padding:0;font-size:clamp(1rem,5vw,1.35rem);line-height:1.6;color:var(--ink);white-space:normal;word-break:break-all}
.addr-note{margin-top:8px;font-size:.85rem;color:var(--ink-soft);line-height:1.7}
.btn{appearance:none;cursor:pointer;background:var(--green);color:var(--btn-ink);font:inherit;font-size:1rem;border:3px solid var(--bdc);box-shadow:3px 3px 0 var(--bdc);padding:9px 18px;min-width:96px}
.btn:hover{background:#7ad486}
.btn:active{transform:translate(3px,3px);box-shadow:none}
.btn.done{background:var(--sky)}
.btn:focus-visible,.nav a:focus-visible,summary:focus-visible,.theme:focus-visible{outline:3px solid var(--sky-mid);outline-offset:2px}

/* notice */
.notice-sec{padding:40px 0 0}
.notice{background:var(--surface);border:var(--bd);box-shadow:var(--sh);padding:18px 20px;position:relative}
.notice::before{content:"";position:absolute;left:0;top:0;bottom:0;width:10px;background:#f0b13e;border-right:3px solid var(--bdc)}
.notice-title{margin:0 0 8px 14px;font-size:.72rem;color:var(--ink)}
.notice ul{margin:0 0 0 14px;padding-left:1.2em}
.notice li{margin:4px 0;color:var(--ink-soft)}
.notice strong{color:var(--ink)}

/* sections */
.sec{padding:72px 0}
.sec.alt{background:var(--mist);border-block:3px solid var(--bdc)}
.num{margin:0;font-size:.7rem;color:var(--sky-mid)}
h2{margin:6px 0 24px;font-size:clamp(1.05rem,3.6vw,1.45rem);line-height:1.7}
h3{margin:0 0 8px;font-size:1.2rem}
.sec-lead{margin:-6px 0 26px;color:var(--ink-soft);max-width:44em}
.note{margin:22px 0 0;color:var(--ink-soft);font-size:.95rem}
.small{margin:12px 0 0;color:var(--ink-soft);font-size:.9rem;line-height:1.7}

.grid2,.grid3,.grid4{display:grid;gap:18px}
.grid2{grid-template-columns:repeat(auto-fit,minmax(min(100%,300px),1fr))}
.grid3{grid-template-columns:repeat(auto-fit,minmax(min(100%,260px),1fr))}
.grid4{grid-template-columns:repeat(auto-fit,minmax(min(100%,230px),1fr))}
.card,.world,.rules li,details,.table-wrap{background:var(--surface);border:var(--bd);box-shadow:var(--sh)}
.card{padding:22px}
.card p{margin:0}

.steps{margin:0;padding-left:1.4em}
.steps li{margin:6px 0}
.steps li::marker{color:var(--sky-deep)}
.friend{margin-top:18px;padding-top:14px;border-top:3px dashed var(--line)}
.friend-title{font-weight:700;margin:0 0 4px;color:var(--ink)}
.friend p{margin:0 0 8px;color:var(--ink-soft)}

.world{padding:22px 22px 22px 32px;position:relative}
.world::before{content:"";position:absolute;left:0;top:0;bottom:0;width:10px;background:var(--c);border-right:3px solid var(--bdc)}
.world p{margin:0;color:var(--ink-soft)}
.w-lobby{--c:#cfd8df}.w-survival{--c:#5fbf6b}.w-resource{--c:#f0b13e}.w-pvp{--c:#ee6a6a}

.table-wrap{overflow-x:auto}
table{border-collapse:collapse;width:100%;min-width:480px}
th,td{text-align:left;padding:12px 16px;border-bottom:2px solid var(--bdc);vertical-align:top}
th{font-size:.62rem;background:var(--th);color:var(--th-ink)}
tbody tr:last-child td{border-bottom:0}
td:first-child{white-space:nowrap}

.rules{margin:0;padding:0;list-style:none;display:grid;gap:14px}
.rules li{padding:14px 18px 14px 52px;position:relative}
.rules li::before{content:"";position:absolute;left:18px;top:22px;width:14px;height:14px;border:2px solid var(--bdc);background:var(--green)}

.faq{display:grid;gap:14px}
details{padding:0 18px}
summary{cursor:pointer;list-style:none;padding:16px 32px 16px 0;font-weight:700;position:relative}
summary::-webkit-details-marker{display:none}
summary::after{content:"+";position:absolute;right:0;top:50%;transform:translateY(-50%);font-family:var(--pixel);font-size:1rem;color:var(--sky-deep)}
details[open] summary::after{content:"-"}
details p{margin:0 0 16px;color:var(--ink-soft)}

.foot{padding:44px 0 56px;border-top:3px solid var(--bdc);text-align:center}
.foot-brand{margin:0;font-size:1rem}
.foot .small{margin-top:6px}

@media(max-width:560px){
  .sec{padding:56px 0}
  .hero-in{padding:52px 0 60px}
  .addr-row{flex-direction:column;align-items:stretch}
  .btn{width:100%}
  .brand span{display:none}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}