/* Utilities */
.pseudo-underline {
    position: relative;
    display: inline-block;
}

.pseudo-underline::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -2px;
    width: 100%;
    height: 2px;
    background: var(--color-primary);
}

.flex-center {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
}

.transition-hover {
    transition: all var(--transition-fast);
}

.transition-hover:hover {
    transform: translateY(-2px);
}

@media (max-width: 600px) {
    .responsive-text {
        font-size: 0.9rem;
    }
}

/* Card */
.card {
    border: 3px solid var(--color-primary);
    border-radius: var(--vk-size-radius);
    padding: 1rem;
    box-shadow: inset 0 0 0 1px var(--color-primary);
    background: var(--page-bg);
    color: var(--page-fg);
}

/* Dark mode toggle button */
#dark-mode-toggle {
    position: fixed;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    color: var(--color-primary);
    padding: 0.3rem 0.6rem;
    font-size: 1rem;
    cursor: pointer;
    border-radius: var(--vk-size-radius);
}

/* Page fade classes */
.page-fade-out {
    opacity: 0;
    transition: opacity var(--transition-medium);
}

.page-fade-in {
    opacity: 1;
    transition: opacity var(--transition-medium);
}

/* 差し替え直後の main をほんのりハイライト */
.page-soft-highlight {
    animation: soft-hl 900ms ease both;
}

@keyframes soft-hl {
    0% {
        background: color-mix(in oklab, canvas, highlight 18%);
    }

    100% {
        background: transparent;
    }
}

/* Click bloom animation */
/* ============================
   Click bloom animations（色は currentColor のまま）
   - strong: 遷移直前の強め
   - weak  : 遷移直後の弱め
   ============================ */
@keyframes label-bloom-strong {
    0% {
        color: inherit;
        text-shadow: none;
        filter: brightness(1);
    }

    45% {
        text-shadow:
            0 0 2px currentColor,
            0 0 6px currentColor;
        filter: brightness(1.18);
    }

    100% {
        color: inherit;
        text-shadow: none;
        filter: brightness(1);
    }
}

@keyframes label-bloom-weak {
    0% {
        color: inherit;
        text-shadow: none;
        filter: brightness(1);
    }

    45% {
        text-shadow:
            0 0 1px currentColor,
            0 0 3px currentColor;
        filter: brightness(1.12);
    }

    100% {
        color: inherit;
        text-shadow: none;
        filter: brightness(1);
    }
}

/* 強め発光（遷移直前） */
.click-bloom--strong {
    animation: label-bloom-strong 260ms ease-out both;
    will-change: color, text-shadow, filter;
}

/* 弱め発光（遷移直後） */
.click-bloom--weak {
    animation: label-bloom-weak 180ms ease-out both;
    will-change: color, text-shadow, filter;
}

/* ============================
   Optional accent pulse (橙の“気配”を一瞬だけ)
   - 文字色は不変、text-shadow のみアクセント色
   - JS から .accent-pop をピーク付近の短時間だけ付与
   ============================ */
@keyframes label-accent-pulse {
    0% {
        text-shadow: none;
        filter: brightness(1);
    }

    50% {
        /* ごく控えめなアクセントの後光 */
        text-shadow:
            0 0 1px var(--color-accent),
            0 0 6px var(--color-accent);
        filter: brightness(1.03);
    }

    100% {
        text-shadow: none;
        filter: brightness(1);
    }
}

.accent-pop {
    /* 110ms 程度。bloom のピーク近辺で重ねる前提 */
    animation: label-accent-pulse 110ms ease-out both;
    will-change: text-shadow, filter;
}