/* ==================== 基础样式重置 ==================== */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}


/* ==================== 变量与通用 ==================== */

:root {
    --brand-blue: #1e5799;
    /* 核心蓝 */
    --brand-blue-dark: #0d2a4a;
    --brand-blue-light: #2980b9;
    --text-black: #1a1a1a;
    --text-gray: #666666;
    --bg-gray: #f8fafd;
    --transition: all 0.5s cubic-bezier(0.165, 0.84, 0.44, 1);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}


/* ==================== Hero 区域 ==================== */

.hero-section {
    height: 80vh;
    background: url('../images/products-hero.jpg') center/cover no-repeat;
    /* 建议放一张工程大景图 */
    background-color: var(--brand-blue-dark);
    position: relative;
    display: flex;
    align-items: center;
    color: #fff;
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to right, rgba(13, 42, 74, 0.9), rgba(30, 87, 153, 0.4));
}

.hero-container {
    position: relative;
    z-index: 2;
}

.hero-text {
    max-width: 600px;
}

.hero-title {
    font-size: 56px;
    font-weight: 700;
    margin-bottom: 10px;
}

.hero-subtitle {
    font-size: 18px;
    letter-spacing: 2px;
    color: var(--brand-blue-light);
    margin-bottom: 25px;
}

.hero-line {
    width: 60px;
    height: 4px;
    background: #fff;
    margin-bottom: 25px;
}

.hero-description {
    font-size: 16px;
    line-height: 1.8;
    opacity: 0.9;
}


/* ==================== 优势区域 ==================== */

.advantage-section {
    background: var(--brand-blue-dark);
    padding: 40px 0;
    color: #fff;
}

.advantage-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.adv-item {
    display: flex;
    flex-direction: column;
}

.adv-num {
    font-size: 24px;
    font-weight: 700;
    color: var(--brand-blue-light);
    margin-bottom: 10px;
}

.adv-item h4 {
    font-size: 20px;
    margin-bottom: 10px;
}

.adv-item p {
    font-size: 14px;
    opacity: 0.7;
}


/* ==================== 业务网格 (严格整齐) ==================== */

.business-section {
    padding: 100px 0;
    background: var(--bg-gray);
}

.section-header {
    margin-bottom: 60px;
    text-align: left;
}

.section-header.centered {
    text-align: center;
}

.sub-title {
    color: var(--brand-blue);
    font-weight: 700;
    letter-spacing: 2px;
    font-size: 14px;
}

.main-title {
    font-size: 36px;
    margin: 10px 0;
    color: var(--text-black);
}

.title-bar {
    width: 50px;
    height: 3px;
    background: var(--brand-blue);
}

.business-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    /* 2x2 对称 */
    gap: 40px;
}

.business-card {
    background: #fff;
    display: flex;
    flex-direction: column;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
    opacity: 0;
    transform: translateY(30px);
    overflow: hidden;
    height: 100%;
    /* 保证高度一致 */
}

.business-card.active {
    opacity: 1;
    transform: translateY(0);
}

.business-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.card-image {
    height: 200px;
    background-color: #eee;
    background-size: cover;
    background-position: center;
}


/* 核心业务板块背景图片 */

.img1 {
    background-image: linear-gradient(rgba(0, 0, 0, 0.2), rgba(0, 0, 0, 0.2)), url('../images/DJI_20250729154141_0213_D.jpg');
}

.img2 {
    background-image: linear-gradient(rgba(0, 0, 0, 0.2), rgba(0, 0, 0, 0.2)), url('../images/DJI_20250730104754_0282_D.jpg');
}

.img3 {
    background-image: linear-gradient(rgba(0, 0, 0, 0.2), rgba(0, 0, 0, 0.2)), url('../images/DJJ_3932-已增强-降噪.jpg');
}

.img4 {
    background-image: linear-gradient(rgba(0, 0, 0, 0.2), rgba(0, 0, 0, 0.2)), url('../images/DJJ_3937-已增强-降噪.jpg');
}

.card-content {
    padding: 40px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.card-icon {
    width: 40px;
    height: 40px;
    color: var(--brand-blue);
    margin-bottom: 20px;
}

.card-title {
    font-size: 24px;
    margin-bottom: 15px;
    color: var(--text-black);
}

.card-desc {
    font-size: 15px;
    color: var(--text-gray);
    line-height: 1.8;
    margin-bottom: 30px;
    flex-grow: 1;
}

.card-link {
    color: var(--brand-blue);
    font-weight: 700;
    text-decoration: none;
    font-size: 14px;
    position: relative;
}

.card-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--brand-blue);
    transition: var(--transition);
}

.card-link:hover::after {
    width: 100%;
}


/* 案例链接样式 */

.card-cases {
    margin-bottom: 20px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
}

.case-tag {
    font-size: 13px;
    color: var(--text-gray);
    font-weight: 500;
}

.case-link {
    display: inline-block;
    padding: 4px 12px;
    background: var(--bg-gray);
    color: var(--brand-blue);
    font-size: 13px;
    text-decoration: none;
    border-radius: 4px;
    transition: var(--transition);
    border: 1px solid transparent;
}

.case-link:hover {
    background: var(--brand-blue);
    color: #fff;
    transform: translateY(-2px);
}


/* ==================== 解决方案板块 ==================== */

.solution-section {
    padding: 60px 0;
}

.solution-box {
    background: var(--brand-blue);
    padding: 60px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: #fff;
    border-radius: 4px;
}

.solution-info {
    max-width: 70%;
}

.solution-title {
    font-size: 32px;
    margin-bottom: 15px;
}

.solution-tags {
    display: flex;
    gap: 15px;
    margin-top: 20px;
    font-size: 14px;
    opacity: 0.8;
}

.cta-btn {
    background: #fff;
    color: var(--brand-blue);
    padding: 15px 35px;
    text-decoration: none;
    font-weight: 700;
    border-radius: 4px;
    transition: var(--transition);
}

.cta-btn:hover {
    background: var(--brand-blue-light);
    color: #fff;
}


/* ==================== 服务流程 ==================== */

.process-section {
    padding: 100px 0;
    background: #fff;
}

.process-steps {
    display: flex;
    justify-content: space-between;
    margin-top: 60px;
    position: relative;
}

.step-item {
    flex: 1;
    text-align: center;
    position: relative;
    padding: 0 10px;
    opacity: 0;
    transition: var(--transition);
}

.step-item.active {
    opacity: 1;
}

.step-circle {
    width: 60px;
    height: 60px;
    background: var(--bg-gray);
    border: 2px solid var(--brand-blue);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-weight: 700;
    color: var(--brand-blue);
    position: relative;
    z-index: 2;
}

.step-line {
    position: absolute;
    top: 30px;
    left: 50%;
    width: 100%;
    height: 2px;
    background: #eee;
    z-index: 1;
}

.step-item:last-child .step-line {
    display: none;
}

.step-item h4 {
    font-size: 20px;
    margin-bottom: 10px;
}

.step-item p {
    font-size: 14px;
    color: var(--text-gray);
}


/* ==================== 响应式适配 ==================== */

@media (max-width: 992px) {
    .business-grid {
        grid-template-columns: 1fr;
    }
    .advantage-grid {
        grid-template-columns: 1fr;
    }
    .solution-box {
        flex-direction: column;
        text-align: center;
        gap: 30px;
    }
    .process-steps {
        flex-direction: column;
        gap: 50px;
    }
    .step-line {
        display: none;
    }
}