body {
    background: radial-gradient(
        circle at top,
        #2a2a2a 0%,
        #1e1e1e 60%,
        #171717 100%
    );
}

.center {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    gap: 28px;
}

/* Großer, responsiver Button */
.app-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: min(92vw, 420px);
    min-height: 56px;
    padding: 14px 18px;

    font-size: clamp(16px, 2.4vw, 20px);
    font-weight: 700;
    line-height: 1.1;

    border: 0;
    border-radius: 16px;
    cursor: pointer;

    background: #111;
    color: #fff;

    box-shadow: 0 10px 22px rgba(0, 0, 0, 0.18);
    transition: transform 0.08s ease, box-shadow 0.18s ease, opacity 0.18s ease;
}

.app-button:hover {
    transform: translateY(-1px);
    box-shadow: 0 14px 28px rgba(0, 0, 0, 0.22);
}

.app-button:active {
    transform: translateY(0);
    box-shadow: 0 8px 18px rgba(0, 0, 0, 0.16);
    opacity: 0.92;
}

.app-button:focus-visible {
    outline: 3px solid rgba(0, 0, 0, 0.35);
    outline-offset: 4px;
}

.wifi-icon {
    filter: drop-shadow(0 0 12px rgba(255, 255, 255, 0.25));
}

@media (max-width: 360px) {
    .app-button {
        min-height: 52px;
        border-radius: 14px;
    }

    .wifi-icon {
        width: min(55vw, 140px);
    }
}

@media (max-height: 600px) {
    .wifi-icon {
        width: min(35vw, 120px);
    }
}