/* Constellation — styles */
* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { height: 100%; overflow: hidden; }
body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: #05080f;
    color: #e8ecf6;
    -webkit-user-select: none; user-select: none;
    -webkit-tap-highlight-color: transparent;
}
#app { position: relative; width: 100vw; height: 100vh; }
#scene { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }

.topbtns { position: fixed; top: 12px; right: 12px; z-index: 10; display: flex; gap: 8px; }
.icon-btn {
    width: 38px; height: 38px; border-radius: 50%;
    border: 1px solid rgba(255,255,255,.14);
    background: rgba(8,12,20,.6); color: #c8d4e8;
    display: flex; align-items: center; justify-content: center;
    cursor: pointer; backdrop-filter: blur(6px);
    transition: background .2s, transform .15s;
}
.icon-btn:hover { background: rgba(28,38,58,.75); transform: scale(1.06); }

.go {
    position: fixed; left: 50%; bottom: 46px; transform: translateX(-50%);
    z-index: 12; padding: 13px 34px; border-radius: 24px; border: 0; cursor: pointer;
    background: linear-gradient(135deg, #b8d0f0, #7a9ad0); color: #0c1220;
    font-size: 14px; font-weight: 700; letter-spacing: .12em;
    box-shadow: 0 8px 24px rgba(140,170,220,.22);
    transition: transform .15s, opacity .2s;
}
.go:hover { transform: translateX(-50%) translateY(-1px); }
.go.done { opacity: .35; cursor: default; }

#status {
    position: fixed; left: 12px; bottom: 12px; z-index: 8;
    font-size: 11.5px; letter-spacing: .04em; color: rgba(200,215,240,.55);
    text-shadow: 0 1px 3px rgba(0,0,0,.7); pointer-events: none;
}
#hint {
    position: fixed; top: 14px; left: 50%; transform: translate(-50%, -8px);
    z-index: 9; font-size: 12.5px; color: #d8e4ff;
    background: rgba(8,12,22,.85); padding: 7px 14px; border-radius: 20px;
    border: 1px solid rgba(150,180,230,.3); opacity: 0; pointer-events: none;
    transition: opacity .4s, transform .4s; max-width: 88vw; text-align: center;
}
#hint.show { opacity: 1; transform: translate(-50%, 0); }