:root {
    --neon: #00f2fe;
    --cyan: #22d3ee;
    --text: #e2e8f0;
    --muted: #94a3b8;
}

* {
    box-sizing: border-box;
}

/* The root needs its own dark fill. Body's background propagates to the page canvas
   only while html has none, and Safari still paints the rubber-band overscroll strips
   above and below the document from the root - which is white by default. */
html {
    background: #020617;
    color-scheme: dark;
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: 'Inter', 'Noto Sans JP', system-ui, sans-serif;
    background: linear-gradient(-45deg, #020617, #0f172a, #0b1120, #083344);
    background-size: 400% 400%;
    animation: bgPulse 15s ease infinite;
    color: var(--text);
    overflow-x: hidden;
    -webkit-tap-highlight-color: transparent;
}

@keyframes bgPulse {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.languages {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 6px;
}

.languages svg {
    flex: none;
    color: var(--muted);
}

.languages button {
    font: inherit;
    font-size: 0.95rem;
    font-weight: 600;
    min-height: 44px;
    padding: 0 14px;
    border-radius: 999px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    background: rgba(255, 255, 255, 0.05);
    color: var(--text);
    cursor: pointer;
}

.languages button[aria-pressed="true"] {
    color: #fff;
    border-color: rgba(0, 242, 254, 0.6);
    background: rgba(6, 182, 212, 0.15);
}

.swap [data-i18n] {
    animation: swap 0.4s ease;
}

@keyframes swap {
    from { opacity: 0; transform: translateY(4px); }
}

@media (prefers-reduced-motion: reduce) {
    body,
    .swap [data-i18n] {
        animation: none;
    }
}