html, body {
    margin: 0;
    padding: 0;
    min-height: 100%;
    font-family: Arial, sans-serif;
    background-color: black;
    color: white;
}

@media (max-width: 600px) {
    .center-button {
        width: 90%;
    }
}

/* ===== Bottom Navigation Bar ===== */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: 56px;
    background: #111;
    border-top: 1px solid #2a2a2a;
    display: flex;
    z-index: 9999;
    padding-bottom: env(safe-area-inset-bottom);
}

.bottom-nav-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: #555;
    text-decoration: none;
    font-size: 10px;
    gap: 3px;
    transition: color 0.15s;
    -webkit-tap-highlight-color: transparent;
}

.bottom-nav-item.active {
    color: #1a73e8;
}

.bottom-nav-item:hover {
    color: #999;
}

.bottom-nav-item.active:hover {
    color: #1a73e8;
}

/* ===== Common Toggle Switch (iOS Style) ===== */
.sym-toggle {
    width: 28px;
    height: 16px;
    appearance: none;
    -webkit-appearance: none;
    background: #444;
    border-radius: 8px;
    cursor: pointer;
    position: relative;
    transition: background 0.2s;
    vertical-align: middle;
    flex-shrink: 0;
}

.sym-toggle:checked {
    background: #4caf50;
}

.sym-toggle::after {
    content: '';
    position: absolute;
    width: 12px;
    height: 12px;
    background: #fff;
    border-radius: 50%;
    top: 2px;
    left: 2px;
    transition: left 0.2s;
}

.sym-toggle:checked::after {
    left: 14px;
}