/* 核心指标：书架手风琴 — flex-grow 主导、定高无抖动、GPU 友好（Apple / Linear 系克制动效） */

:root {
    --mb-ease: cubic-bezier(0.4, 0, 0.2, 1);
    --mb-duration: 0.48s;
    --mb-shelf-h: clamp(19.5rem, 26vh, 24.5rem);
    --mb-spine-w: 4.125rem;
}

.metrics-bookshelf {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    align-items: stretch;
    gap: 0.35rem;
    width: 100%;
    max-width: 80rem;
    margin-left: auto;
    margin-right: auto;
    height: var(--mb-shelf-h);
    min-height: var(--mb-shelf-h);
    max-height: var(--mb-shelf-h);
    overflow: hidden;
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
}

.metrics-bookshelf,
.metrics-bookshelf * {
    max-width: 100%;
}

.metrics-bookshelf--faq {
    --mb-shelf-h: clamp(18rem, 24vh, 22rem);
}

.metrics-bookshelf__panel {
    position: relative;
    box-sizing: border-box;
    margin: 0;
    font: inherit;
    color: inherit;
    -webkit-appearance: none;
    appearance: none;
    display: flex;
    flex-direction: row;
    align-items: stretch;
    flex: 0 0 var(--mb-spine-w);
    min-width: 0;
    height: 100%;
    overflow: hidden;
    border-radius: 1.5rem;
    border: 1px solid #e2e8f0;
    background: #f8fafc;
    /* 与展开态相同内边距，避免切换时 CLS */
    padding: 1.125rem 0.75rem;
    cursor: pointer;
    text-align: left;
    box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
    transform: translateZ(0);
    backface-visibility: hidden;
    transition:
        flex-grow var(--mb-duration) var(--mb-ease),
        flex-shrink var(--mb-duration) var(--mb-ease),
        flex-basis var(--mb-duration) var(--mb-ease),
        border-color 0.32s var(--mb-ease),
        box-shadow 0.32s var(--mb-ease),
        background-color 0.32s var(--mb-ease);
}

.metrics-bookshelf__panel:hover {
    border-color: #cbd5e1;
    background: #fff;
}

.metrics-bookshelf__panel:focus-visible {
    outline: 2px solid #3b82f6;
    outline-offset: 3px;
    z-index: 2;
}

.metrics-bookshelf__panel.is-expanded {
    flex: 1 1 0%;
    min-width: 0;
    background: #fff;
    box-shadow: 0 18px 44px -14px rgba(15, 23, 42, 0.1);
    z-index: 1;
}

.metrics-bookshelf__panel--blue.is-expanded {
    border-color: #bfdbfe;
}
.metrics-bookshelf__panel--green.is-expanded {
    border-color: #bbf7d0;
}
.metrics-bookshelf__panel--purple.is-expanded {
    border-color: #e9d5ff;
}
.metrics-bookshelf__panel--amber.is-expanded {
    border-color: #fde68a;
}
.metrics-bookshelf__panel--red.is-expanded {
    border-color: #fecaca;
}

/* 书脊列：收起时占满窄 panel 内容区；展开时宽度压到 0 */
.metrics-bookshelf__spine {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    gap: 0.5rem;
    flex: 1 1 0%;
    min-width: 0;
    overflow: hidden;
    writing-mode: horizontal-tb;
    transform: translateZ(0);
    transition:
        flex-grow var(--mb-duration) var(--mb-ease),
        flex-shrink var(--mb-duration) var(--mb-ease),
        flex-basis var(--mb-duration) var(--mb-ease),
        opacity calc(var(--mb-duration) * 0.85) var(--mb-ease);
}

.metrics-bookshelf__panel.is-expanded .metrics-bookshelf__spine {
    flex: 0 0 0;
    min-width: 0;
    opacity: 0;
    pointer-events: none;
}

.metrics-bookshelf__spine-icon {
    flex-shrink: 0;
    width: 2.25rem;
    height: 2.25rem;
    border-radius: 0.65rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.metrics-bookshelf__spine-label {
    writing-mode: vertical-rl;
    text-orientation: upright;
    -webkit-text-orientation: upright;
    font-size: 0.75rem;
    font-weight: 700;
    color: #0f172a;
    text-align: center;
    line-height: 1.4;
    letter-spacing: 0.14em;
    white-space: nowrap;
    max-height: 11rem;
    overflow: hidden;
}

/* 展开区：始终占位在 flex 行内，绝不 absolute；宽度用 flex 挤压 */
.metrics-bookshelf__expand {
    box-sizing: border-box;
    flex: 0 0 0%;
    min-width: 0;
    height: 100%;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    min-height: 0;
    padding: 0;
    opacity: 0;
    pointer-events: none;
    transform: translate3d(0, 0.625rem, 0);
    transition:
        flex-grow var(--mb-duration) var(--mb-ease),
        flex-shrink var(--mb-duration) var(--mb-ease),
        flex-basis var(--mb-duration) var(--mb-ease),
        opacity calc(var(--mb-duration) * 0.9) var(--mb-ease),
        transform calc(var(--mb-duration) * 0.9) var(--mb-ease);
}

.metrics-bookshelf__panel.is-expanded .metrics-bookshelf__expand {
    flex: 1 1 0%;
    min-width: 0;
    opacity: 1;
    pointer-events: auto;
    transform: translate3d(0, 0, 0);
}

.metrics-bookshelf__expand-head {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-shrink: 0;
}

.metrics-bookshelf__expand-icon {
    width: 3rem;
    height: 3rem;
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.metrics-bookshelf__expand-title {
    font-size: 1.125rem;
    font-weight: 700;
    color: #0f172a;
    line-height: 1.35;
}

.metrics-bookshelf__expand-body {
    font-size: 1.0625rem;
    color: #475569;
    line-height: 1.75;
    flex: 1 1 auto;
    min-height: 0;
    overflow: hidden;
    display: -webkit-box;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: 12;
    line-clamp: 12;
}

/* 说明下方：客户案例示例（五项均有） */
.metrics-bookshelf__expand--has-example-slot .metrics-bookshelf__expand-body {
    flex: 0 1 auto;
    display: block;
    -webkit-line-clamp: unset;
    line-clamp: unset;
    overflow: visible;
}

.metrics-bookshelf__example {
    flex: 1 1 0;
    min-height: 0;
    margin-top: 0.75rem;
    padding: 1rem 1.1rem;
    border-radius: 0.75rem;
    border: 1px solid #e2e8f0;
    background: linear-gradient(180deg, #f8fafc 0%, #f1f5f9 100%);
    box-sizing: border-box;
    min-width: 0;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
}

.metrics-bookshelf__example-text {
    margin: 0;
    font-size: 1.0625rem;
    line-height: 1.75;
    color: #475569;
}

@media (max-width: 1023px) {
    .metrics-bookshelf {
        --mb-shelf-h: 25rem;
        overflow-x: auto;
        overflow-y: hidden;
        -webkit-overflow-scrolling: touch;
        scroll-snap-type: x proximity;
        gap: 0.4rem;
        padding-bottom: 0.15rem;
        contain: layout paint;
    }

    .metrics-bookshelf__panel {
        flex: 0 0 var(--mb-spine-w);
        scroll-snap-align: start;
    }

    .metrics-bookshelf__panel.is-expanded {
        flex: 1 0 min(88vw, 26rem);
        min-width: min(88vw, 26rem);
    }
}

@media (max-width: 640px) {
    .metrics-bookshelf {
        --mb-shelf-h: 28rem;
        gap: 0.5rem;
        padding-inline: 0.05rem;
    }

    .metrics-bookshelf__panel {
        border-radius: 1rem;
        padding: 0.95rem 0.65rem;
    }

    .metrics-bookshelf__panel.is-expanded {
        flex-basis: min(86vw, 23rem);
        min-width: min(86vw, 23rem);
    }

    .metrics-bookshelf__expand-head {
        gap: 0.75rem;
        margin-bottom: 0.75rem;
    }

    .metrics-bookshelf__expand-icon {
        width: 2.5rem;
        height: 2.5rem;
        border-radius: 0.75rem;
    }

    .metrics-bookshelf__expand-title {
        font-size: 1rem;
    }

    .metrics-bookshelf__expand-body,
    .metrics-bookshelf__example-text {
        font-size: 0.9rem;
        line-height: 1.65;
    }

    .metrics-bookshelf__example {
        padding: 0.85rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    .metrics-bookshelf__panel,
    .metrics-bookshelf__spine,
    .metrics-bookshelf__expand {
        transition-duration: 0.01ms !important;
        transition-delay: 0s !important;
    }
}