:root{color-scheme:dark;--navy:#061326;--panel:#0b1d34;--line:#244666;--cyan:#65dcf5;--blue:#2478f5;--text:#eff7ff;--muted:#9db1c8}*{box-sizing:border-box}body{margin:0;min-height:100vh;background:radial-gradient(circle at 50% 15%,#153253 0,var(--navy) 48%,#030a14 100%);color:var(--text);font-family:Poppins,sans-serif}header{height:72px;display:flex;align-items:center;justify-content:space-between;padding:0 clamp(20px,5vw,72px);border-bottom:1px solid #18324e;background:#061326cc}header a{color:#fff;font-weight:800;text-decoration:none}header span{color:#7290ad;font-size:.72rem;font-weight:700;letter-spacing:.12em}main{min-height:calc(100vh - 72px);display:grid;place-items:center;padding:32px 20px}.join-card{width:min(520px,100%);padding:clamp(28px,5vw,48px);border:1px solid var(--line);border-radius:24px;background:#091a2f;box-shadow:0 30px 90px #0008;text-align:center}.eyebrow{color:var(--cyan);font-size:.76rem;font-weight:800;letter-spacing:.18em}.join-card h1{margin:12px 0 8px;font-size:clamp(2rem,8vw,3rem)}.join-card>p{margin:0 0 28px;color:var(--muted)}form{display:grid;gap:12px}label{text-align:left;color:#bdd0e4;font-size:.75rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase}input{width:100%;padding:16px;border:1px solid #365877;border-radius:12px;background:#061324;color:#fff;font:800 1.8rem/1 Poppins,sans-serif;letter-spacing:.28em;text-align:center;text-transform:uppercase;outline:none}input:focus{border-color:var(--blue);box-shadow:0 0 0 3px #2478f52b}input[aria-invalid=true]{border-color:#ee6c75}#join-error{min-height:20px;color:#ff9ba3;font-size:.8rem}button{padding:14px;border:1px solid #54a5ff;border-radius:11px;background:linear-gradient(135deg,#1765d9,#2687ff);color:#fff;font:800 .82rem Poppins,sans-serif;letter-spacing:.08em;cursor:pointer}.library-link{display:inline-block;margin-top:24px;color:#91abc5;font-size:.82rem;text-decoration:none}@media(max-width:520px){header span{display:none}.join-card{padding:30px 20px}input{font-size:1.55rem}}