/* 物理AI·具身智能虚实共生训练平台 */

.pai-banner {
    position: relative;
    overflow: hidden;
    min-height: 40rem;
    background: url("../images/physicalAI/banner.jpg") no-repeat center center;
    background-size: cover;
    background-color: #f7fbff;
}

.pai-banner-inner {
    display: flex;
    align-items: center;
    min-height: 40rem;
    padding: 3.4rem 0;
    box-sizing: border-box;
}

.pai-banner-text {
    max-width: 52%;
    position: relative;
    z-index: 1;
}

.pai-banner-title {
    margin: 0 0 2rem;
    font-size: 4rem;
    font-weight: 700;
    color: #333333;
    line-height: 1.25;
}

.pai-banner-desc {
    margin: 0 0 4.5rem;
    font-size: 1.6rem;
    color: #666666;
    line-height: 2.4rem;
}

.pai-banner-cta {
    width: 12rem;
    height: 4rem;
    display: flex;
    justify-content: center;
    align-items: center;
    border: 1px solid var(--brand-color, rgba(224, 25, 39, 1));
    border-radius: 0.4rem;
    background: #fff;
    color: var(--brand-color, rgba(224, 25, 39, 1));
    font-size: 1.6rem;
    font-weight: 500;
    cursor: pointer;
}

.pai-banner-cta:hover {
    background: #fff5f5;
}

/* 二级锚点导航 */
.po-subnav {
    background: #fafafa;
    height: 7rem;
    width: 100%;
    position: relative;
    z-index: 100;
}

.po-subnav.sticky {
    position: fixed;
    top: 7rem;
    left: 0;
    right: 0;
    width: 100%;
    box-shadow: 0 0.2rem 1rem rgba(0, 0, 0, 0.1);
}

.po-subnav .container {
    padding: 0;
}

.po-subnav-container {
    display: flex;
    justify-content: space-around;
}

.po-subnav-link {
    text-decoration: none;
    font-weight: 500;
    font-size: 1.6rem;
    color: #333333;
    line-height: 7rem;
    display: inline-flex;
    align-items: center;
    height: 100%;
    border-bottom: 0.2rem solid transparent;
    padding: 0 0.4rem;
    -webkit-tap-highlight-color: transparent;
}

@media (hover: hover) and (pointer: fine) {
    .po-subnav-link:hover {
        color: #e21927;
    }
}

.po-subnav-link--active {
    color: #e21927;
    border-bottom-color: #e21927;
}

/* 章节通用 */

.pai-section-header {
    text-align: center;
    margin-bottom: 3.6rem;
}

.pai-section-desc {
    margin: 1.2rem auto 0;
    font-size: 1.6rem;
    color: #666666;
    line-height: 2.4rem;
}

/* 平台能力 */
.pai-capability-section {
    background: #f7f8fa;
}

.pai-capability-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 3rem;
}

.pai-capability-card {
    background: linear-gradient(180deg, #FFFFFFFF 0%, #E5EEFF42 100%);
    border-radius: 1.2rem;
    padding: 3.2rem 3rem;
    box-shadow: 0 0.4rem 1.6rem rgba(15, 40, 80, 0.06);
    box-sizing: border-box;
}

.pai-capability-head {
    display: flex;
    align-items: center;
    gap: 1.6rem;
    margin-bottom: 1.6rem;
}

.pai-capability-num {
    flex-shrink: 0;
    font-size: 4rem;
    font-weight: 700;
    font-style: italic;
    line-height: 1;
    background: linear-gradient(180deg, #8B9BFF 0%, #A8D4FF 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
}

.pai-capability-title {
    margin: 0;
    font-size: 2rem;
    font-weight: 700;
    color: #333333;
    line-height: 1.4;
}

.pai-capability-desc {
    margin: 0;
    font-size: 1.5rem;
    color: #666666;
    line-height: 2.4rem;
}

/* 技术优势 */
.pai-advantage-section {
    background: url("../images/physicalAI/advantage-bg.jpg") no-repeat center center;
    background-size: cover;
}

.pai-advantage-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 3rem;
}

.pai-advantage-card {
    background: #ffffff;
    border-radius: 1.2rem;
    padding: 3.6rem 2.4rem 3.2rem;
    text-align: center;
    box-shadow: 0 0.4rem 1.6rem rgba(15, 40, 80, 0.06);
    box-sizing: border-box;
}

.pai-advantage-icon {
    display: block;
    width: 14rem;
    height: 14rem;
    object-fit: contain;
    margin: 0 auto 2rem;
}

.pai-advantage-title {
    margin: 0;
    font-size: 1.8rem;
    font-weight: 700;
    color: #333333;
    line-height: 1.5;
}

/* 应用价值 */
.pai-value-section {
    background: #ffffff;
}

.pai-value-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 3rem;
}

.pai-value-card {
    position: relative;
    border-radius: 1.6rem;
    overflow: hidden;
    min-height: 26rem;
    box-shadow: 0 0.4rem 1.6rem rgba(15, 40, 80, 0.06);
}

.pai-value-bg {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-position: center;
    display: block;
}

.pai-value-text {
    position: relative;
    z-index: 1;
    max-width: 48%;
    min-height: 26rem;
    padding: 0 0 2.4rem 3.2rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    box-sizing: border-box;
}

.pai-value-title {
    margin: 0 0 2.2rem;
    font-size: 2rem;
    font-weight: 700;
    color: #333333;
    line-height: 1.4;
}

.pai-value-desc {
    margin: 0;
    font-size: 1.5rem;
    color: #666666;
    line-height: 2.4rem;
}

/* 平板 */
@media (max-width: 1023px) {
    .pai-banner-text {
        max-width: 60%;
    }

    .pai-banner-title {
        font-size: 3.2rem;
    }

    .pai-advantage-grid {
        gap: 1.6rem;
    }

    .pai-advantage-icon {
        width: 11rem;
        height: 11rem;
    }

    .pai-advantage-title {
        font-size: 1.6rem;
    }

    .pai-value-title {
        font-size: 1.8rem;
    }
}

/* 手机 */
@media (max-width: 767px) {
    .pai-banner {
        min-height: 0;
        background-position: center top;
        background-size: cover;
    }

    .pai-banner-inner {
        min-height: 24rem;
        padding: 2.4rem 0 2rem;
        align-items: flex-start;
    }

    .pai-banner-text {
        max-width: 100%;
        background: linear-gradient(180deg, rgba(247, 251, 255, 0.92) 0%, rgba(247, 251, 255, 0.75) 70%, transparent 100%);
        padding-bottom: 1.2rem;
    }

    .pai-banner-title {
        font-size: 2.4rem;
        margin-bottom: 1.2rem;
    }

    .pai-banner-desc {
        font-size: 1.4rem;
        line-height: 2.2rem;
        margin-bottom: 2.4rem;
    }

    .pai-banner-cta {
        font-size: 1.4rem;
        width: 10rem;
        height: 3.2rem;
    }

    .po-subnav {
        height: auto;
    }

    .po-subnav.sticky {
        top: 56px;
    }

    .po-subnav-link {
        line-height: 5rem;
        font-size: 1.4rem;
        padding: 0 1.2rem;
        white-space: nowrap;
    }

    .pai-section-header {
        margin-bottom: 2.4rem;
    }

    .pai-section-desc {
        font-size: 1.4rem;
        line-height: 2.2rem;
    }

    .pai-capability-grid,
    .pai-advantage-grid,
    .pai-value-grid {
        grid-template-columns: 1fr;
        gap: 1.6rem;
    }

    .pai-capability-card {
        padding: 2.4rem 2rem;
    }

    .pai-capability-num {
        font-size: 3.2rem;
    }

    .pai-capability-title {
        font-size: 1.8rem;
    }

    .pai-capability-desc {
        font-size: 1.4rem;
        line-height: 2.2rem;
    }

    .pai-advantage-card {
        padding: 2.8rem 2rem 2.4rem;
    }

    .pai-advantage-icon {
        width: 12rem;
        height: 12rem;
        margin-bottom: 1.6rem;
    }

    .pai-advantage-title {
        font-size: 1.6rem;
    }

    .pai-value-card {
        min-height: 20rem;
    }

    .pai-value-text {
        max-width: 58%;
        min-height: 20rem;
        padding: 2rem 1.6rem 2rem 2rem;
    }

    .pai-value-title {
        font-size: 1.8rem;
    }

    .pai-value-desc {
        font-size: 1.4rem;
        line-height: 2.2rem;
    }
}