/* ============================================
   宏远重工 - 企业官网样式
   商务稳重风格 | 深蓝+金色配色
   ============================================ */

/* ---------- 基础变量 ---------- */
:root {
    --primary: #1a2a4a;
    --primary-light: #2c4a7a;
    --accent: #c9a96e;
    --accent-light: #e0c896;
    --dark: #0d1525;
    --dark-light: #162238;
    --text: #333333;
    --text-light: #666666;
    --text-lighter: #999999;
    --bg-light: #f5f7fa;
    --bg-white: #ffffff;
    --border: #e2e8f0;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.12);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --radius: 8px;
}

/* ---------- Reset ---------- */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 16px;
    line-height: 1.7;
    color: var(--text);
    background: var(--bg-white);
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul,
ol {
    list-style: none;
}

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

/* ---------- 公共组件 ---------- */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.section {
    padding: 90px 0;
    position: relative;
}

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

.section-header.light h2,
.section-header.light p {
    color: #fff;
}

.section-tag {
    display: inline-block;
    font-size: 13px;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--accent);
    font-weight: 600;
    margin-bottom: 10px;
}

.section-header h2 {
    font-size: 36px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 12px;
    position: relative;
    display: inline-block;
}

.section-header h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--accent);
    border-radius: 2px;
}

.section-header p {
    margin-top: 20px;
    font-size: 16px;
    color: var(--text-light);
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 14px 32px;
    border-radius: var(--radius);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    text-align: center;
}

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

.btn-primary:hover {
    background: var(--accent-light);
    color: var(--dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(201, 169, 110, 0.4);
}

.btn-outline-light {
    background: transparent;
    color: #fff;
    border: 2px solid rgba(255, 255, 255, 0.6);
}

.btn-outline-light:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.btn-block {
    width: 100%;
    padding: 16px;
    font-size: 16px;
}

/* ---------- 顶部通知栏 ---------- */
.top-bar {
    background: var(--dark);
    color: rgba(255, 255, 255, 0.7);
    font-size: 13px;
    padding: 8px 0;
}

.top-bar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
}

.top-bar span {
    white-space: nowrap;
}

.top-bar strong {
    color: var(--accent);
}

.top-bar .container span:nth-child(2) strong {
    color: #4fc3f7;
}

/* ---------- 导航栏 ---------- */
.header {
    position: fixed;
    top: 33px;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(13, 21, 37, 0.95);
    backdrop-filter: blur(10px);
    transition: var(--transition);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.header.scrolled {
    top: 0;
    box-shadow: 0 2px 30px rgba(0, 0, 0, 0.3);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 75px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    font-size: 32px;
    color: var(--accent);
}

.logo-text {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}

.logo-cn {
    font-size: 22px;
    font-weight: 700;
    color: #fff;
    letter-spacing: 2px;
}

.logo-en {
    font-size: 9px;
    color: var(--text-lighter);
    letter-spacing: 1px;
    text-transform: uppercase;
}

.nav {
    display: flex;
    gap: 8px;
}

.nav-link {
    color: rgba(255, 255, 255, 0.75);
    font-size: 15px;
    padding: 8px 16px;
    border-radius: var(--radius);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 60%;
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.mobile-menu-btn span {
    width: 25px;
    height: 2px;
    background: #fff;
    border-radius: 2px;
    transition: var(--transition);
}

/* ---------- 移动端菜单 ---------- */
.mobile-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--dark);
    z-index: 999;
    padding: 80px 30px 30px;
    display: flex;
    flex-direction: column;
    gap: 5px;
    transition: right 0.3s ease;
    box-shadow: -5px 0 30px rgba(0, 0, 0, 0.3);
}

.mobile-menu.active {
    right: 0;
}

.mobile-menu a {
    color: rgba(255, 255, 255, 0.8);
    font-size: 16px;
    padding: 14px 16px;
    border-radius: var(--radius);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.mobile-menu a:hover {
    color: var(--accent);
    background: rgba(255, 255, 255, 0.03);
}

/* ---------- Hero 区域 ---------- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, #0d1525 0%, #1a2a4a 40%, #0d2137 100%);
}

.hero-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(201, 169, 110, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(44, 74, 122, 0.3) 0%, transparent 40%);
}

.hero-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
    background-size: 60px 60px;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1440 320'%3E%3Cpath fill='%231a2a4a' fill-opacity='0.3' d='M0,160L48,144C96,128,192,96,288,106.7C384,117,480,171,576,181.3C672,192,768,160,864,138.7C960,117,1056,107,1152,117.3C1248,128,1344,160,1392,176L1440,192L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z'%3E%3C/path%3E%3C/svg%3E") no-repeat bottom / cover;
}

.hero-content {
    position: relative;
    z-index: 2;
    color: #fff;
    max-width: 800px;
}

.hero-badge {
    display: inline-block;
    background: rgba(201, 169, 110, 0.15);
    border: 1px solid rgba(201, 169, 110, 0.4);
    color: var(--accent-light);
    padding: 6px 18px;
    border-radius: 20px;
    font-size: 14px;
    margin-bottom: 24px;
}

.hero h1 {
    font-size: 56px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
    background: linear-gradient(135deg, #fff 0%, var(--accent-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.75);
    max-width: 600px;
    margin-bottom: 40px;
    line-height: 1.8;
}

.hero-stats {
    display: flex;
    gap: 50px;
    margin-bottom: 40px;
}

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

.stat-number {
    font-size: 42px;
    font-weight: 800;
    color: var(--accent);
    line-height: 1;
}

.stat-label {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
    margin-top: 4px;
}

.hero-btns {
    display: flex;
    gap: 16px;
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: rgba(255, 255, 255, 0.4);
    font-size: 12px;
    animation: float 2s ease-in-out infinite;
}

.scroll-arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid rgba(255, 255, 255, 0.3);
    border-bottom: 2px solid rgba(255, 255, 255, 0.3);
    transform: rotate(45deg);
}

@keyframes float {

    0%,
    100% {
        transform: translateX(-50%) translateY(0);
    }

    50% {
        transform: translateX(-50%) translateY(8px);
    }
}

/* ---------- 服务领域 ---------- */
.section-services {
    background: var(--bg-light);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.service-card {
    background: var(--bg-white);
    border-radius: var(--radius);
    padding: 36px 28px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border);
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent);
}

.service-icon {
    font-size: 42px;
    margin-bottom: 16px;
}

.service-card h3 {
    font-size: 20px;
    color: var(--primary);
    margin-bottom: 12px;
}

.service-card p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.7;
    margin-bottom: 16px;
}

.service-features {
    border-top: 1px solid var(--border);
    padding-top: 14px;
}

.service-features li {
    font-size: 13px;
    color: var(--text-light);
    padding: 4px 0;
    padding-left: 16px;
    position: relative;
}

.service-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

/* ---------- 关于我们 ---------- */
.section-about {
    background: var(--bg-white);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-images {
    position: relative;
}

.about-img-main {
    width: 100%;
    height: 400px;
    border-radius: var(--radius);
    background: linear-gradient(135deg, #1a2a4a 0%, #2c4a7a 100%);
    position: relative;
    overflow: hidden;
}

.about-img-main::after {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 30% 40%, rgba(201, 169, 110, 0.2) 0%, transparent 50%),
        linear-gradient(180deg, transparent 40%, rgba(0, 0, 0, 0.3) 100%);
}

.about-img-sub {
    position: absolute;
    bottom: -30px;
    right: -20px;
    width: 200px;
    height: 160px;
    border-radius: var(--radius);
    background: linear-gradient(135deg, #0f2027 0%, #203a43 100%);
    border: 4px solid #fff;
    box-shadow: var(--shadow);
}

.about-experience {
    position: absolute;
    top: -20px;
    left: -20px;
    background: var(--accent);
    color: #fff;
    padding: 24px 28px;
    border-radius: var(--radius);
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.exp-number {
    font-size: 36px;
    font-weight: 800;
    display: block;
    line-height: 1;
}

.exp-text {
    font-size: 13px;
    opacity: 0.9;
}

.about-content h2 {
    font-size: 32px;
    color: var(--primary);
    margin: 10px 0 16px;
}

.about-lead {
    font-size: 16px;
    color: var(--text-light);
    margin-bottom: 24px;
}

.about-stats-row {
    display: flex;
    gap: 30px;
    margin-bottom: 24px;
    padding: 20px 0;
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.about-stat {
    display: flex;
    flex-direction: column;
}

.about-stat-num {
    font-size: 24px;
    font-weight: 800;
    color: var(--primary);
}

.about-stat-num .unit {
    font-size: 14px;
    font-weight: 600;
}

.about-stat-label {
    font-size: 13px;
    color: var(--text-lighter);
}

.about-content>p {
    font-size: 15px;
    color: var(--text-light);
    margin-bottom: 24px;
}

.milestones {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 28px;
}

.milestone {
    display: flex;
    align-items: center;
    gap: 8px;
    background: var(--bg-light);
    padding: 8px 16px;
    border-radius: 20px;
}

.milestone-year {
    font-weight: 700;
    color: var(--accent);
    font-size: 14px;
}

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

/* ---------- 产品与服务 ---------- */
.section-products {
    background: linear-gradient(180deg, var(--bg-light) 0%, #eef2f7 100%);
}

.products-tabs {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 40px;
}

.tab-btn {
    padding: 12px 32px;
    border: 2px solid var(--border);
    background: var(--bg-white);
    border-radius: 30px;
    font-size: 15px;
    font-weight: 600;
    color: var(--text-light);
    cursor: pointer;
    transition: var(--transition);
}

.tab-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

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

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

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

.products-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.product-card {
    background: var(--bg-white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.product-img {
    width: 100%;
    height: 180px;
    background-size: cover !important;
    background-position: center !important;
    background-repeat: no-repeat !important;
    position: relative;
}

.product-img::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, transparent 50%, rgba(0, 0, 0, 0.35) 100%);
}

.product-info {
    padding: 20px;
}

.product-info h4 {
    font-size: 17px;
    color: var(--primary);
    margin-bottom: 8px;
}

.product-info p {
    font-size: 13px;
    color: var(--text-light);
    margin-bottom: 12px;
}

.product-tag {
    display: inline-block;
    background: var(--bg-light);
    color: var(--primary);
    font-size: 12px;
    font-weight: 600;
    padding: 4px 12px;
    border-radius: 4px;
}

/* 解决方案列表 */
.solutions-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.solution-item {
    display: flex;
    gap: 20px;
    background: var(--bg-white);
    padding: 28px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.solution-item:hover {
    transform: translateX(6px);
    box-shadow: var(--shadow-lg);
}

.solution-icon {
    font-size: 36px;
    flex-shrink: 0;
}

.solution-text h4 {
    font-size: 18px;
    color: var(--primary);
    margin-bottom: 8px;
}

.solution-text p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.7;
}

/* ---------- 新闻资讯 ---------- */
.section-news {
    background: var(--bg-white);
}

.news-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    grid-template-rows: 1fr 1fr;
    gap: 24px;
}

.news-card {
    background: var(--bg-white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.news-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.news-featured {
    grid-row: span 2;
}

.news-img {
    width: 100%;
    height: 180px;
}

.news-featured .news-img {
    height: 280px;
}

.news-body {
    padding: 20px 24px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.news-date {
    font-size: 13px;
    color: var(--accent);
    font-weight: 600;
}

.news-category {
    display: inline-block;
    font-size: 11px;
    background: var(--bg-light);
    color: var(--text-light);
    padding: 2px 10px;
    border-radius: 10px;
    margin: 8px 0;
    align-self: flex-start;
}

.news-body h3 {
    font-size: 17px;
    color: var(--primary);
    margin-bottom: 10px;
    line-height: 1.5;
    flex: 1;
}

.news-featured .news-body h3 {
    font-size: 22px;
}

.news-body p {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 14px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-link {
    font-size: 14px;
    color: var(--primary);
    font-weight: 600;
}

.news-link:hover {
    color: var(--accent);
}

/* ---------- 合作伙伴 ---------- */
.section-partners {
    background: var(--primary);
    padding: 70px 0;
}

.section-partners .section-header h2 {
    color: #fff;
}

.section-partners .section-header h2::after {
    background: var(--accent);
}

.section-partners .section-header p {
    color: rgba(255, 255, 255, 0.6);
}

.partners-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.partner-logo {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius);
    padding: 28px;
    text-align: center;
    font-size: 18px;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.6);
    transition: var(--transition);
}

.partner-logo:hover {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    transform: scale(1.05);
}

/* ---------- 联系我们 ---------- */
.section-contact {
    background: linear-gradient(135deg, #0d1525 0%, #1a2a4a 100%);
    padding: 90px 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 60px;
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 28px;
}

.contact-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.contact-icon {
    font-size: 24px;
    width: 50px;
    height: 50px;
    background: rgba(201, 169, 110, 0.15);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-item h4 {
    color: var(--accent);
    font-size: 15px;
    margin-bottom: 4px;
}

.contact-item p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 15px;
}

.contact-form-wrap {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius);
    padding: 36px;
}

.contact-form-wrap h3 {
    color: #fff;
    font-size: 22px;
    margin-bottom: 24px;
}

.contact-form input,
.contact-form select,
.contact-form textarea {
    width: 100%;
    padding: 12px 16px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--radius);
    color: #fff;
    font-size: 14px;
    margin-bottom: 16px;
    transition: var(--transition);
    font-family: inherit;
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
    color: rgba(255, 255, 255, 0.35);
}

.contact-form input:focus,
.contact-form select:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.08);
}

.contact-form .form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.contact-form .form-row input {
    margin-bottom: 16px;
}

.contact-form select option {
    background: var(--dark);
    color: #fff;
}

/* ---------- 页脚 ---------- */
.footer {
    background: var(--dark);
    padding: 60px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
}

.footer-logo-text {
    font-size: 20px;
    font-weight: 700;
    color: #fff;
}

.footer-desc {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
    line-height: 1.8;
    margin-bottom: 20px;
}

.footer-social {
    display: flex;
    gap: 10px;
}

.social-link {
    width: 36px;
    height: 36px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
}

.social-link:hover {
    background: var(--accent);
    color: #fff;
    transform: translateY(-2px);
}

.footer-col h4 {
    color: #fff;
    font-size: 16px;
    margin-bottom: 16px;
    position: relative;
    padding-bottom: 10px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background: var(--accent);
}

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col ul li a {
    color: rgba(255, 255, 255, 0.5);
    font-size: 14px;
}

.footer-col ul li a:hover {
    color: var(--accent);
    padding-left: 4px;
}

.footer-contact li {
    color: rgba(255, 255, 255, 0.5);
    font-size: 14px;
}

.footer-bottom {
    padding: 24px 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.3);
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.3);
}

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

/* ---------- 回到顶部 ---------- */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 44px;
    height: 44px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 50%;
    font-size: 20px;
    cursor: pointer;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--primary);
    transform: translateY(-3px);
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .solutions-list {
        grid-template-columns: 1fr;
    }

    .news-grid {
        grid-template-columns: 1fr 1fr;
    }

    .news-featured {
        grid-row: span 1;
        grid-column: span 2;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }

    .partners-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    .top-bar {
        display: none;
    }

    .header {
        top: 0;
    }

    .nav {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero h1 {
        font-size: 36px;
    }

    .hero-stats {
        gap: 24px;
    }

    .stat-number {
        font-size: 32px;
    }

    .hero-btns {
        flex-direction: column;
        align-items: flex-start;
    }

    .section {
        padding: 60px 0;
    }

    .section-header h2 {
        font-size: 28px;
    }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .about-images {
        margin-bottom: 40px;
    }

    .services-grid {
        grid-template-columns: 1fr;
    }

    .products-grid {
        grid-template-columns: 1fr;
    }

    .news-grid {
        grid-template-columns: 1fr;
    }

    .news-featured {
        grid-column: span 1;
    }

    .contact-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .partners-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .contact-form .form-row {
        grid-template-columns: 1fr;
    }
}

/* ---------- 滚动动画 ---------- */
[data-aos] {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-aos].aos-animate {
    opacity: 1;
    transform: translateY(0);
}

[data-aos-delay="100"].aos-animate {
    transition-delay: 0.1s;
}

[data-aos-delay="200"].aos-animate {
    transition-delay: 0.2s;
}

[data-aos-delay="300"].aos-animate {
    transition-delay: 0.3s;
}