:root{color-scheme:dark;font-family:"Yu Gothic",Meiryo,system-ui,sans-serif;color:#eaf8fc;background:#03121c}
*{box-sizing:border-box}body{margin:0;min-height:100vh;min-height:100dvh;overflow-x:hidden}.ocean{position:fixed;inset:0;z-index:-1;overflow:hidden;background:radial-gradient(ellipse at 50% 0%,#18536a,transparent 62%),linear-gradient(#071f2c,#020b13)}.ocean img{position:absolute;width:max(700px,85vw);max-width:none;top:20%;left:-20%;opacity:.055;filter:brightness(0) invert(1);animation:swim 55s linear infinite}@keyframes swim{to{transform:translateX(125vw)}}
header{max-width:900px;margin:auto;padding:24px 20px}.wordmark{font:clamp(22px,4vw,28px) Georgia,serif;letter-spacing:.02em}.wordmark span{color:#8fc7d5;font-size:.82em}
main{display:grid;place-items:center;min-height:calc(100dvh - 85px);padding:0 18px 40px}.notice{width:min(100%,620px);padding:clamp(25px,5vw,48px);text-align:center;border:1px solid #74bdd177;border-top:1px solid #b4ecf4b0;border-radius:18px;background:linear-gradient(145deg,#122e3ce8,#071a27f0);box-shadow:0 28px 90px #0007,0 0 48px #62cee217}.eyebrow{margin:0;color:#9fd5e3;font-size:12px;font-weight:700;letter-spacing:.16em}.lock{display:grid;place-items:center;width:150px;height:150px;margin:28px auto 12px;border:1px solid #76c5d7a6;border-radius:50%;background:radial-gradient(circle,#245a6f,#0b2a3a);box-shadow:0 0 45px #64cfe549,inset 0 0 22px #b6f0ff23;font-size:94px;line-height:1}.notice h1{margin:15px 0 12px;font-family:"Yu Mincho","Hiragino Mincho ProN",serif;font-size:clamp(26px,5vw,36px)}.lead{margin:0;color:#bbd1da;font-size:15px;line-height:1.9}.options{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin:27px 0}.options span{display:grid;gap:4px;padding:14px 8px;border:1px solid #527383;border-radius:8px;background:#102a38;color:#d2e5ea;font-size:14px;font-weight:700}.options small{color:#9abac7;font-size:12px}.return{display:flex;align-items:center;justify-content:center;gap:20px;min-height:52px;padding:12px 18px;border:1px solid #a6e4f3;border-radius:7px;background:linear-gradient(115deg,#a2e6ee,#69b9d8);color:#052033;text-decoration:none;font-weight:800}.return:hover{filter:brightness(1.08)}.return:focus-visible{outline:3px solid #e5fbff;outline-offset:4px}
@media(max-width:420px){header{padding:20px 18px}main{min-height:calc(100dvh - 65px);padding:0 14px 22px}.notice{padding:25px 19px}.lock{width:125px;height:125px;font-size:78px;margin-top:22px}.lead br{display:none}.options{margin:22px 0}}
@media(prefers-reduced-motion:reduce){.ocean img{animation:none}}