*{margin:0;padding:0;box-sizing:border-box}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  background:#0b1020;color:#e7ecf5;min-height:100vh;
  background-image:
    radial-gradient(1px 1px at 20% 30%,rgba(255,255,255,.4),transparent),
    radial-gradient(1px 1px at 70% 20%,rgba(255,255,255,.3),transparent),
    radial-gradient(1px 1px at 40% 70%,rgba(255,255,255,.25),transparent),
    radial-gradient(1px 1px at 85% 60%,rgba(255,255,255,.35),transparent),
    radial-gradient(1.5px 1.5px at 55% 45%,rgba(120,180,255,.5),transparent),
    radial-gradient(1px 1px at 10% 80%,rgba(255,255,255,.2),transparent);
}
a{color:inherit;text-decoration:none}

/* ===== 密碼閘門 ===== */
#authGate{
  position:fixed;inset:0;background:rgba(5,8,18,.96);z-index:1000;
  display:flex;align-items:center;justify-content:center;padding:24px;
}
.gate{
  background:#141b2e;border:1px solid #26314d;border-radius:18px;
  padding:40px 32px;width:100%;max-width:380px;text-align:center;
  box-shadow:0 24px 70px rgba(0,0,0,.5);
}
.gate .emoji{font-size:2.4rem;margin-bottom:12px}
.gate h1{font-size:1.4rem;margin-bottom:6px;color:#f3f6fc}
.gate p{color:#93a0b8;font-size:.88rem;margin-bottom:26px;line-height:1.5}
.gate input[type=password]{
  width:100%;padding:14px 16px;background:#0b1020;border:1px solid #26314d;
  border-radius:10px;color:#f3f6fc;font-size:1rem;outline:none;transition:border .2s;
}
.gate input[type=password]:focus{border-color:#5b8cff}
.gate .btn{
  width:100%;padding:14px;margin-top:14px;background:#5b8cff;color:#fff;border:none;
  border-radius:10px;font-size:1rem;font-weight:600;cursor:pointer;transition:background .2s;
}
.gate .btn:hover{background:#3f74f0}
.gate .err{color:#ff7b7b;font-size:.85rem;margin-top:12px;min-height:1.2em}
.gate .toggle{margin-top:16px}
.gate .toggle a{color:#6b7791;font-size:.8rem;cursor:pointer}
.gate .toggle a:hover{color:#93a0b8}
body.locked{overflow:hidden}

/* ===== 主內容 ===== */
.wrap{max-width:1000px;margin:0 auto;padding:40px 24px 80px}
.topbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:8px;flex-wrap:wrap;gap:12px}
.back{color:#8fa0bd;font-size:.9rem}
.back:hover{color:#c7d2e5}
.lock-btn{background:#1c2438;color:#aebbd2;border:none;padding:8px 14px;border-radius:8px;cursor:pointer;font-size:.82rem}
.lock-btn:hover{background:#273149}

.hero{text-align:center;margin:32px 0 48px}
.hero .planet{font-size:3.4rem;margin-bottom:14px}
.hero h1{font-size:2rem;background:linear-gradient(90deg,#7aa2ff,#9b6bff,#5b8cff);-webkit-background-clip:text;background-clip:text;color:transparent;margin-bottom:10px}
.hero p{color:#93a0b8;font-size:1rem;max-width:560px;margin:0 auto;line-height:1.6}

.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:20px;margin-top:8px}
.card{
  background:#141b2e;border:1px solid #26314d;border-radius:16px;padding:28px 24px;
  transition:transform .2s,border-color .2s,box-shadow .2s;display:block;
}
.card:hover{transform:translateY(-4px);border-color:#5b8cff;box-shadow:0 16px 40px rgba(0,0,0,.35)}
.card .icon{font-size:2.2rem;margin-bottom:14px}
.card h2{font-size:1.2rem;color:#f3f6fc;margin-bottom:6px}
.card .en{color:#5b8cff;font-size:.8rem;margin-bottom:12px;letter-spacing:.04em}
.card p{color:#8fa0bd;font-size:.88rem;line-height:1.55}
.card .arrow{margin-top:16px;color:#5b8cff;font-size:.85rem;font-weight:600}

/* ===== 課程頁 ===== */
.cat-head{margin:24px 0 32px}
.cat-head .icon{font-size:2.6rem;margin-bottom:12px}
.cat-head h1{font-size:1.8rem;color:#f3f6fc;margin-bottom:6px}
.cat-head .en{color:#5b8cff;font-size:.85rem;margin-bottom:12px}
.cat-head p{color:#93a0b8;font-size:.95rem;max-width:600px;line-height:1.6}

.subgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:16px}
.subcard{
  background:#141b2e;border:1px solid #26314d;border-radius:14px;padding:22px 20px;
  transition:border-color .2s;
}
.subcard:hover{border-color:#3d4d73}
.subcard .badge{
  display:inline-block;background:#1c2c52;color:#7aa2ff;font-size:.72rem;font-weight:600;
  padding:4px 10px;border-radius:20px;margin-bottom:12px;letter-spacing:.03em;
}
.subcard h3{font-size:1.05rem;color:#f3f6fc;margin-bottom:8px}
.subcard p{color:#8fa0bd;font-size:.85rem;line-height:1.5}
.subcard .soon{margin-top:12px;color:#5f6d87;font-size:.78rem}

.note{margin-top:40px;padding:16px 18px;background:#101627;border:1px solid #222c44;border-radius:12px;color:#7d8aa3;font-size:.82rem;line-height:1.6}