/* ================= 1. 基础重置 ================= */

/* ================= 2. 视频背景核心容器 ================= */
.video-container {
    position: relative;
    width: 100%;
    height: 100vh;
    overflow: hidden;
}

/* 全屏视频样式 */
.video-container video {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 100%;
    height: 100%;
    min-width: 100%;
    min-height: 100%;
    object-fit: cover;
    /* 保持比例完美裁剪铺满 */
    transform: translate(-50%, -50%);
    z-index: 1;
}

/* ================= 3. 电影感遮罩层 ================= */
/* 核心：压低视频亮度，提升文字可读性与高级感 */
.video-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg,
            rgba(0, 0, 0, 0.6) 0%,
            rgba(0, 0, 0, 0.3) 100%);
    z-index: 2;
    /* 压在视频上方 */
}

/* ================= 4. 前景内容排版 ================= */
.content-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 3;
    /* 浮在最上层 */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: #ffffff;
    text-align: center;
    padding: 0 20px;
}

/* 顶部微型导航标签（增加网页精致感） */
.brand-tag {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 6px;
    margin-bottom: 20px;
    color: rgba(255, 255, 255, 0.7);
    opacity: 0;
    animation: fadeInDown 1s ease forwards;
}

/* 大标题 */
.main-title {
    font-size: 3.5rem;
    font-weight: 300;
    letter-spacing: 8px;
    margin-bottom: 25px;
    line-height: 1.3;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
    opacity: 0;
    animation: fadeInUp 1s ease 0.3s forwards;
}

/* 副标题 */
.sub-title {
    font-size: 1.1rem;
    font-weight: 300;
    letter-spacing: 2px;
    max-width: 650px;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 40px;
    opacity: 0;
    animation: fadeInUp 1s ease 0.6s forwards;
}

/* 极简留白按钮 */
.cta-button {
    padding: 14px 36px;
    font-size: 0.95rem;
    color: #ffffff;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.4);
    border-radius: 4px;
    cursor: pointer;
    letter-spacing: 2px;
    transition: all 0.4s cubic-bezier(0.25, 1, 0.5, 1);
    backdrop-filter: blur(4px);
    /* 按钮本身带微弱毛玻璃 */
    opacity: 0;
    animation: fadeInUp 1s ease 0.9s forwards;
}

/* 按钮悬停动效 */
.cta-button:hover {
    background: #ffffff;
    color: #000000;
    border-color: #ffffff;
    box-shadow: 0 10px 20px rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

/* ================= 5. 入场动画效果 ================= */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ================= 6. 移动端响应式优化 ================= */
@media (max-width: 768px) {
    .main-title {
        font-size: 2.2rem;
        letter-spacing: 4px;
    }

    .sub-title {
        font-size: 0.95rem;
        line-height: 1.6;
    }

    .cta-button {
        padding: 12px 28px;
        font-size: 0.9rem;
    }
}