* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    --bg: #111;
    --fg: #F3F3F3;
    --accent: #FFC107;

    font-family: "Courier New", monospace;
    color: var(--fg);
    background-color: var(--bg);
    background-image:
        radial-gradient(circle, color-mix(in srgb, var(--fg) 10%, transparent) 3%, transparent 3%),
        radial-gradient(circle, color-mix(in srgb, var(--fg) 10%, transparent) 3%, transparent 3%);
    background-size: 20px 20px;
    background-position: 0 0, 10px 10px;
    min-height: 100dvh;
    display: flex;
    justify-content: center;
}

.smartlink {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: auto 0;
    padding: 3rem 1.5rem;
    max-width: 400px;
    width: 100%;
}

.smartlink-artwork {
    width: 100%;
    max-width: 300px;
    border-radius: 8px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.6);
}

.smartlink-album {
    font-size: 24px;
    color: var(--accent);
    margin-top: 1.5rem;
    text-align: center;
}

.smartlink-artist {
    font-size: 16px;
    color: var(--fg);
    margin-top: 0.5rem;
    text-align: center;
}

.smartlink-buttons {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    width: 100%;
    margin-top: 2rem;
}

.smartlink-btn {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    width: 100%;
    padding: 0.875rem 1.25rem;
    font-family: "Courier New", monospace;
    font-size: 16px;
    text-align: left;
    text-decoration: none;
    color: var(--fg);
    border: 1px solid color-mix(in srgb, var(--fg) 30%, transparent);
    border-radius: 6px;
    transition: background-color 0.3s, color 0.3s, border-color 0.3s;
}

.smartlink-btn:hover {
    background-color: var(--accent);
    color: var(--bg);
    border-color: var(--accent);
}

.smartlink-btn-icon {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
    object-fit: contain;
}

/* ホバー時にアイコンの色を反転（白→黒） */
.smartlink-btn:hover .smartlink-btn-icon {
    filter: brightness(0);
}

/* YouTube Musicはホバー時も公式カラー（赤）を維持 */
.smartlink-btn:hover .smartlink-btn-icon-yt {
    filter: none;
}

.smartlink-mv {
    width: 100%;
    margin-top: 2rem;
}

.smartlink-mv iframe {
    width: 100%;
    aspect-ratio: 16 / 9;
    border-radius: 6px;
}

.smartlink-back {
    margin-top: 2.5rem;
    font-family: "Courier New", monospace;
    font-size: 14px;
    text-decoration: none;
    color: var(--fg);
    opacity: 0.6;
    transition: opacity 0.3s, color 0.3s;
}

.smartlink-back:hover {
    opacity: 1;
    color: var(--accent);
}