/* ===== 基础与变量 ===== */
:root {
    --primary: #2c7a7b;
    --primary-dark: #1e5959;
    --primary-light: #4fd1c5;
    --accent: #d69e2e;
    --accent-light: #ecc94b;
    --text: #2d3748;
    --text-light: #718096;
    --bg: #ffffff;
    --bg-alt: #f5f9f9;
    --border: #e2e8f0;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 12px 32px rgba(44, 122, 123, 0.15);
    --radius: 14px;
    --nav-w: 140px;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 70px;
}

body {
    font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.75;
    -webkit-font-smoothing: antialiased;
}

img {
    max-width: 100%;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color 0.2s;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== 顶部品牌栏 ===== */
.top-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 64px;
    background: rgba(255, 255, 255, 0.96);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--border);
    z-index: 100;
}

.top-bar-inner {
    max-width: 1200px;
    height: 100%;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 22px;
    font-weight: 700;
}

.logo-mark {
    background: var(--primary);
    color: #fff;
    padding: 4px 10px;
    border-radius: 8px;
    letter-spacing: 1px;
}

.logo-text {
    color: var(--primary);
}

.top-contact {
    font-size: 14px;
    color: var(--text-light);
}

.top-contact span::before {
    content: "☎ ";
    color: var(--accent);
}

/* ===== 右侧固定导航 ===== */
.side-nav {
    position: fixed;
    right: 30px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 90;
}

.side-nav ul {
    list-style: none;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border);
    border-radius: 40px;
    padding: 16px 10px;
    box-shadow: var(--shadow);
}

.side-nav-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 6px;
    position: relative;
    color: var(--text-light);
    font-size: 13px;
}

.side-nav-link .dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #cbd5e0;
    transition: all 0.25s;
    flex-shrink: 0;
}

.side-nav-link em {
    font-style: normal;
    white-space: nowrap;
    opacity: 0.85;
    transition: opacity 0.25s;
}

.side-nav-link:hover em,
.side-nav-link.active em {
    opacity: 1;
}

.side-nav-link:hover .dot {
    background: var(--primary-light);
    transform: scale(1.2);
}

.side-nav-link.active {
    color: var(--primary);
}

.side-nav-link.active .dot {
    background: var(--primary);
    box-shadow: 0 0 0 4px rgba(44, 122, 123, 0.18);
    transform: scale(1.25);
}

/* ===== Banner ===== */
.banner {
    position: relative;
    height: 100vh;
    min-height: 640px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: #fff;
    overflow: hidden;
    margin-top: 64px;
}

.banner-bg {
    position: absolute;
    inset: 0;
    background: url("https://copyright.bdstatic.com/vcg/creative/02cb9a55192159994084422ebba66834.jpg@h_1280") center/cover no-repeat;
    transform: scale(1.05);
    animation: bgZoom 20s ease-in-out infinite alternate;
}

@keyframes bgZoom {
    from { transform: scale(1.05); }
    to { transform: scale(1.15); }
}

.banner-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(30, 89, 89, 0.85) 0%, rgba(44, 122, 123, 0.6) 50%, rgba(214, 158, 46, 0.4) 100%);
}

.banner-content {
    position: relative;
    z-index: 2;
    max-width: 860px;
    padding: 0 24px;
}

.banner-tag {
    display: inline-block;
    padding: 6px 20px;
    border: 1px solid rgba(255, 255, 255, 0.5);
    border-radius: 30px;
    font-size: 14px;
    letter-spacing: 3px;
    margin-bottom: 24px;
    backdrop-filter: blur(4px);
}

.banner-title {
    font-size: 64px;
    font-weight: 800;
    letter-spacing: 4px;
    margin-bottom: 20px;
    text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.banner-title span {
    color: var(--accent-light);
}

.banner-desc {
    font-size: 19px;
    margin-bottom: 40px;
    opacity: 0.95;
    letter-spacing: 1px;
}

.banner-btns {
    display: flex;
    gap: 18px;
    justify-content: center;
}

.btn {
    padding: 14px 38px;
    border-radius: 40px;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.25s;
    border: 2px solid transparent;
    cursor: pointer;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

.btn-primary:hover {
    background: var(--accent-light);
    border-color: var(--accent-light);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(214, 158, 46, 0.4);
}

.btn-ghost {
    border-color: rgba(255, 255, 255, 0.7);
    color: #fff;
}

.btn-ghost:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}

.banner-stat {
    position: absolute;
    bottom: 40px;
    left: 0;
    right: 0;
    z-index: 2;
    display: flex;
    justify-content: center;
    gap: 56px;
    padding: 0 24px;
}

.stat-item {
    text-align: center;
}

.stat-item strong {
    display: block;
    font-size: 34px;
    font-weight: 800;
    color: #fff;
}

.stat-item span {
    font-size: 14px;
    opacity: 0.85;
}

/* ===== 通用区块 ===== */
.section {
    padding: 100px 0;
}

.section-alt {
    background: var(--bg-alt);
}

.section-head {
    text-align: center;
    margin-bottom: 60px;
}

.section-en {
    display: block;
    font-size: 14px;
    letter-spacing: 4px;
    color: var(--primary-light);
    margin-bottom: 10px;
    font-weight: 600;
}

.section-title {
    font-size: 38px;
    font-weight: 800;
    color: var(--text);
    margin-bottom: 12px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: "";
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    border-radius: 4px;
    margin: 14px auto 0;
}

.section-sub {
    font-size: 17px;
    color: var(--text-light);
}

/* ===== 关于我们 ===== */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
    margin-bottom: 70px;
}

.about-media img {
    width: 100%;
    height: 420px;
    object-fit: cover;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.about-text h3 {
    font-size: 26px;
    font-weight: 700;
    margin-bottom: 18px;
    color: var(--text);
}

.about-text p {
    color: var(--text-light);
    margin-bottom: 16px;
}

.about-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 20px;
}

.about-tags span {
    background: rgba(44, 122, 123, 0.08);
    color: var(--primary);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
}

.value-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.value-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 36px 28px;
    text-align: center;
    transition: all 0.3s;
}

.value-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
    border-color: transparent;
}

.value-icon {
    display: inline-block;
    width: 56px;
    height: 56px;
    line-height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff;
    font-size: 15px;
    font-weight: 700;
    margin-bottom: 18px;
}

.value-card:nth-child(2) .value-icon {
    background: linear-gradient(135deg, var(--accent), #b7791f);
}

.value-card h4 {
    font-size: 20px;
    margin-bottom: 8px;
}

.value-card p {
    color: var(--text-light);
    font-size: 15px;
}

/* ===== 核心业务 ===== */
.business-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 28px;
}

.business-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 40px 36px;
    position: relative;
    overflow: hidden;
    transition: all 0.3s;
    border: 1px solid var(--border);
}

.business-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(180deg, var(--primary), var(--accent));
    transform: scaleY(0);
    transform-origin: top;
    transition: transform 0.3s;
}

.business-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.business-card:hover::before {
    transform: scaleY(1);
}

.biz-num {
    font-size: 48px;
    font-weight: 800;
    color: rgba(44, 122, 123, 0.12);
    line-height: 1;
    margin-bottom: 10px;
}

.business-card h3 {
    font-size: 22px;
    margin-bottom: 12px;
}

.business-card > p {
    color: var(--text-light);
    margin-bottom: 18px;
    font-size: 15px;
}

.biz-points {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 8px 18px;
}

.biz-points li {
    font-size: 14px;
    color: var(--primary);
    padding-left: 16px;
    position: relative;
}

.biz-points li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

/* ===== 智能产品 ===== */
.product-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.product-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: all 0.3s;
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-hover);
}

.product-img {
    height: 220px;
    overflow: hidden;
    background: var(--bg-alt);
}

.product-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s;
}

.product-card:hover .product-img img {
    transform: scale(1.08);
}

.product-body {
    padding: 24px 24px 28px;
}

.product-body h3 {
    font-size: 19px;
    margin-bottom: 8px;
}

.product-body p {
    color: var(--text-light);
    font-size: 14px;
}

/* ===== 实践案例 ===== */
.case-list {
    display: flex;
    flex-direction: column;
    gap: 50px;
}

.case-item {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 0;
    background: #fff;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    align-items: stretch;
}

.case-item.reverse {
    grid-template-columns: 1fr 1.1fr;
}

.case-item.reverse .case-img {
    order: 2;
}

.case-img {
    height: 100%;
    min-height: 320px;
    overflow: hidden;
}

.case-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.case-body {
    padding: 40px 38px;
}

.case-tag {
    display: inline-block;
    background: rgba(44, 122, 123, 0.1);
    color: var(--primary);
    padding: 4px 14px;
    border-radius: 14px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 14px;
}

.case-body h3 {
    font-size: 22px;
    margin-bottom: 12px;
}

.case-body > p {
    color: var(--text-light);
    font-size: 15px;
    margin-bottom: 22px;
}

.case-stats {
    display: flex;
    gap: 30px;
    border-top: 1px solid var(--border);
    padding-top: 20px;
}

.case-stats div {
    text-align: center;
}

.case-stats strong {
    display: block;
    font-size: 26px;
    font-weight: 800;
    color: var(--primary);
}

.case-stats span {
    font-size: 13px;
    color: var(--text-light);
}

/* ===== 联系我们 ===== */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.3fr;
    gap: 40px;
    align-items: stretch;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-card {
    background: var(--bg-alt);
    border-radius: var(--radius);
    padding: 28px 30px;
    border-left: 4px solid var(--primary);
    transition: all 0.25s;
}

.contact-card:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow);
}

.contact-card:nth-child(2) {
    border-left-color: var(--accent);
}

.contact-label {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 8px;
}

.contact-value {
    font-size: 22px;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 6px;
    word-break: break-all;
}

.contact-value a {
    color: var(--primary);
    transition: color 0.2s;
}

.contact-value a:hover {
    color: var(--accent);
}

.contact-note {
    font-size: 13px;
    color: var(--text-light);
}

.contact-map {
    position: relative;
    border-radius: var(--radius);
    overflow: hidden;
    min-height: 480px;
    box-shadow: var(--shadow);
    background: var(--bg-alt);
}

.contact-map iframe {
    width: 100%;
    height: 100%;
    min-height: 480px;
}

.map-tip {
    position: absolute;
    left: 20px;
    bottom: 20px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(6px);
    padding: 14px 22px;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.map-tip strong {
    display: block;
    font-size: 18px;
    color: var(--primary);
    margin-bottom: 2px;
}

.map-tip span {
    font-size: 13px;
    color: var(--text-light);
}

/* ===== 页脚 ===== */
.footer {
    background: #1a2e2e;
    color: #cbd5e0;
    padding: 60px 0 30px;
}

.footer-inner {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 40px;
    align-items: start;
}

.footer-brand .logo-mark {
    background: var(--primary);
}

.footer-brand .logo-text {
    color: #fff;
}

.footer-brand p {
    margin-top: 14px;
    font-size: 14px;
    color: #a0aec0;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-links a {
    font-size: 14px;
    color: #a0aec0;
}

.footer-links a:hover {
    color: var(--accent-light);
}

.footer-copy {
    text-align: right;
    font-size: 13px;
    color: #718096;
}

.footer-copy p {
    margin-bottom: 6px;
}

/* ===== 响应式 ===== */
@media (max-width: 992px) {
    .banner-title { font-size: 46px; }
    .section-title { font-size: 32px; }
    .about-grid,
    .business-grid,
    .product-grid,
    .contact-grid { grid-template-columns: 1fr; }
    .value-cards { grid-template-columns: 1fr; }
    .case-item,
    .case-item.reverse { grid-template-columns: 1fr; }
    .case-item.reverse .case-img { order: 0; }
    .case-img { min-height: 240px; }
    .side-nav { right: 14px; }
    .side-nav-link em { display: none; }
    .footer-inner { grid-template-columns: 1fr; }
    .footer-copy { text-align: left; }
}

@media (max-width: 640px) {
    .banner { min-height: 560px; }
    .banner-title { font-size: 34px; letter-spacing: 2px; }
    .banner-desc { font-size: 16px; }
    .banner-stat { gap: 24px; bottom: 28px; }
    .stat-item strong { font-size: 24px; }
    .section { padding: 70px 0; }
    .section-title { font-size: 26px; }
    .banner-btns { flex-direction: column; gap: 12px; }
    .btn { width: 100%; }
    .top-contact { display: none; }
    .side-nav { display: none; }
    .case-body { padding: 28px 22px; }
    .case-stats { gap: 16px; }
    .case-stats strong { font-size: 20px; }
}

/* ===== 滚动出现动画 ===== */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}