/* yuef-tech-section.css */
.yuef-tech-wrapper {
    width: 100%;
    margin: 0;
    padding: 0;
    background-color: #050505;
    color: #fff;
    font-family: 'Jost', sans-serif;
    position: relative;
    z-index: 10;
}

/* 滚动动画区域 */
.yuef-tech-scroll-stage {
    height: 250vh;
    /* 提供触发滚动的空间 */
    position: relative;
}

.yuef-tech-sticky-box {
    position: sticky;
    top: 0;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background-color: #050505;
}

.yuef-tech-scene {
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    pointer-events: none;
    /* 防止遮挡下方事件 */
}

/* 第一幕：上下两句话 */
.yuef-tech-text-top,
.yuef-tech-text-bottom {
    font-size: 3vw;
    font-weight: 300;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    position: absolute;
    width: 100%;
    text-align: center;
    will-change: transform, opacity;
    white-space: nowrap;
    color: #fff;
}

.yuef-tech-text-top {
    top: 25%;
}

.yuef-tech-text-bottom {
    bottom: 25%;
}

/* 第二幕：中间大文字 */
.yuef-tech-text-center {
    font-size: 4vw;
    font-weight: 500;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    opacity: 0;
    transform: scale(0.5);
    background: linear-gradient(135deg, #f5d78d, #cfa85e);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: #f5d78d;
    /* Fallback */
    will-change: transform, opacity;
}

/* 卡片展示区域 */
.yuef-tech-cards-area {
    padding: 120px 20px;
    background-color: #0a0a0a;
    position: relative;
    z-index: 12;
}

.yuef-tech-cards-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 40px;
    max-width: 1200px;
    margin: 0 auto;
}

.yuef-tech-card-item {
    width: 340px;
    height: 480px;
    perspective: 1500px;
    cursor: pointer;
}

.yuef-tech-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.8s cubic-bezier(0.4, 0.0, 0.2, 1);
    transform-style: preserve-3d;
    border-radius: 12px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.4);
}

.yuef-tech-card-item:hover .yuef-tech-card-inner {
    transform: rotateY(180deg);
}

.yuef-tech-card-front,
.yuef-tech-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    border-radius: 12px;
    overflow: hidden;
}

/* 卡片正面 */
.yuef-tech-card-front {
    background-color: #1a1a1a;
    background-size: cover;
    background-position: center;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
}

.yuef-tech-card-front::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(to bottom, rgba(0, 0, 0, 0.2) 0%, rgba(0, 0, 0, 0.7) 100%);
    z-index: 1;
}

.yuef-tech-card-title-front {
    position: relative;
    z-index: 2;
    font-size: 1.8rem;
    font-weight: 300;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    text-shadow: 0 4px 15px rgba(0, 0, 0, 0.8);
    margin: 0;
    padding: 0 20px;
}

/* 卡片背面 */
.yuef-tech-card-back {
    background: linear-gradient(135deg, #1c1c1c, #0a0a0a);
    color: #d4af37;
    transform: rotateY(180deg);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 30px;
    border: 1px solid rgba(212, 175, 55, 0.2);
}

.yuef-tech-card-back h3 {
    color: #ebd197;
    font-size: 1.6rem;
    font-weight: 500;
    margin-bottom: 20px;
    margin-top: 0;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.yuef-tech-card-back p {
    color: #bbb;
    font-size: 1.05rem;
    line-height: 1.7;
    font-weight: 300;
    margin: 0;
}

/* 响应式调整 */
@media (max-width: 992px) {

    .yuef-tech-text-top,
    .yuef-tech-text-bottom {
        font-size: 4vw;
    }

    .yuef-tech-text-center {
        font-size: 5vw;
    }

    .yuef-tech-card-item {
        width: calc(50% - 20px);
        max-width: 340px;
    }
}

@media (max-width: 768px) {
    .yuef-tech-scroll-stage {
        height: 200vh;
    }

    .yuef-tech-text-top,
    .yuef-tech-text-bottom {
        font-size: 6vw;
        letter-spacing: 0.1em;
    }

    .yuef-tech-text-center {
        font-size: 7vw;
        line-height: 1.3;
    }

    .yuef-tech-card-item {
        width: 100%;
        max-width: 380px;
        height: 400px;
    }

    .yuef-tech-cards-area {
        padding: 80px 20px;
    }
}