/* 全局重置与基础 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: #f0f2f5;
    color: #1a1a2e;
    line-height: 1.6;
    scroll-behavior: smooth;
    transition: background 0.3s, color 0.3s;
}

a {
    color: #1a73e8;
    text-decoration: none;
}

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

/* 暗色模式 */
@media (prefers-color-scheme: dark) {
    body {
        background: #0f0f1a;
        color: #e0e0e0;
    }
    .card, .testimonial, .faq-item, .howto-steps > div, .about-stats .stat, .news .card, .cases .card, .solutions .card, .products .card {
        background: #1a1a2e;
        color: #e0e0e0;
    }
    .card h3, .testimonial .author, .faq-item .question, .about-text h2, .section-title {
        color: #e0e0e0;
    }
    .card p, .testimonial p, .faq-item .answer, .about-text p {
        color: #b0b0b0;
    }
    .header {
        background: #1a1a2e;
    }
    .hero {
        background: linear-gradient(135deg, #1a1a2e, #16213e);
    }
    .about, .solutions, .testimonials, .faq, .howto-steps > div {
        background: #0f0f1a;
    }
    .products, .cases, .news, .howto {
        background: #1a1a2e;
    }
    .contact {
        background: #16213e;
    }
    .footer {
        background: #0a0a15;
    }
    .footer a {
        color: #b0b0b0;
    }
    .footer a:hover {
        color: #e67e22;
    }
    .stat {
        background: #16213e;
    }
    .stat .num {
        color: #f39c12;
    }
    .back-top {
        background: #f39c12;
    }
}

/* 头部导航 */
.header {
    background: linear-gradient(135deg, #2c3e50, #34495e);
    color: #fff;
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.15);
    backdrop-filter: blur(10px);
    background: rgba(44, 62, 80, 0.95);
}

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

.logo {
    font-size: 24px;
    font-weight: 700;
    color: #fff;
    letter-spacing: 1px;
}

.nav {
    display: flex;
    gap: 25px;
}

.nav a {
    color: #fff;
    font-size: 14px;
    padding: 5px 0;
    border-bottom: 2px solid transparent;
    transition: all 0.3s ease;
    position: relative;
}

.nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: #e67e22;
    transition: width 0.3s ease;
}

.nav a:hover::after {
    width: 100%;
}

.menu-btn {
    display: none;
    background: none;
    border: none;
    color: #fff;
    font-size: 28px;
    cursor: pointer;
}

/* 英雄区渐变Banner */
.hero {
    background: linear-gradient(135deg, #2c3e50, #34495e, #4a6274);
    color: #fff;
    padding: 100px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(230, 126, 34, 0.1) 0%, transparent 70%);
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.hero h1 {
    font-size: 42px;
    margin-bottom: 20px;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    position: relative;
    z-index: 1;
}

.hero p {
    font-size: 18px;
    max-width: 800px;
    margin: 0 auto 30px;
    opacity: 0.9;
    position: relative;
    z-index: 1;
}

.hero .btn {
    background: #e67e22;
    color: #fff;
    padding: 14px 40px;
    border-radius: 30px;
    font-size: 16px;
    font-weight: 600;
    display: inline-block;
    transition: all 0.3s ease;
    position: relative;
    z-index: 1;
    box-shadow: 0 4px 15px rgba(230, 126, 34, 0.4);
}

.hero .btn:hover {
    background: #d35400;
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(230, 126, 34, 0.6);
}

/* 通用区块 */
.section {
    padding: 80px 0;
}

.section-title {
    font-size: 32px;
    text-align: center;
    margin-bottom: 50px;
    color: #2c3e50;
    font-weight: 700;
    position: relative;
}

.section-title:after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: #e67e22;
    margin: 10px auto;
}

/* 网格布局 */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

/* 圆角卡片 + 毛玻璃效果 */
.card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
    background: rgba(255, 255, 255, 0.95);
}

.card h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: #2c3e50;
}

.card p {
    font-size: 14px;
    color: #666;
    line-height: 1.7;
}

/* 关于区 */
.about {
    background: #fff;
}

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

.about-text h2 {
    font-size: 28px;
    margin-bottom: 20px;
    color: #2c3e50;
}

.about-text p {
    margin-bottom: 15px;
    font-size: 15px;
    color: #555;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    text-align: center;
}

.stat {
    background: rgba(240, 244, 248, 0.8);
    backdrop-filter: blur(5px);
    border-radius: 16px;
    padding: 25px;
    transition: all 0.3s ease;
}

.stat:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.stat .num {
    font-size: 36px;
    font-weight: 700;
    color: #e67e22;
}

.stat .label {
    font-size: 14px;
    color: #666;
    margin-top: 5px;
}

/* 产品区 */
.products {
    background: #f0f4f8;
}

.products .card {
    text-align: center;
}

.products .card svg {
    width: 60px;
    height: 60px;
    margin-bottom: 15px;
    fill: #2c3e50;
    transition: transform 0.3s ease;
}

.products .card:hover svg {
    transform: rotate(10deg) scale(1.1);
}

/* 解决方案 */
.solutions {
    background: #fff;
}

/* 案例 */
.cases {
    background: #f0f4f8;
}

.cases .card {
    border-left: 4px solid #e67e22;
}

/* 评价 */
.testimonials {
    background: #fff;
}

.testimonial {
    background: rgba(249, 249, 249, 0.8);
    backdrop-filter: blur(5px);
    border-radius: 16px;
    padding: 30px;
    position: relative;
    transition: all 0.3s ease;
}

.testimonial:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.1);
}

.testimonial:before {
    content: '"';
    font-size: 50px;
    color: #e67e22;
    position: absolute;
    top: -10px;
    left: 15px;
    opacity: 0.3;
}

.testimonial p {
    font-size: 14px;
    color: #555;
    margin-bottom: 10px;
    font-style: italic;
}

.testimonial .author {
    font-weight: 600;
    color: #2c3e50;
}

/* 新闻 */
.news {
    background: #f0f4f8;
}

.news .card {
    border-bottom: 3px solid #e67e22;
}

.news .card .date {
    font-size: 12px;
    color: #999;
    margin-bottom: 8px;
    display: block;
}

.news .card .read-more {
    color: #e67e22;
    font-weight: 600;
    font-size: 13px;
    transition: all 0.3s ease;
}

.news .card .read-more:hover {
    color: #d35400;
    padding-left: 5px;
}

/* FAQ */
.faq {
    background: #fff;
}

.faq-item {
    border-bottom: 1px solid #eee;
    padding: 18px 0;
    transition: all 0.3s ease;
}

.faq-item .question {
    font-weight: 600;
    font-size: 16px;
    color: #2c3e50;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: color 0.3s ease;
}

.faq-item .question:hover {
    color: #e67e22;
}

.faq-item .question:after {
    content: '+';
    font-size: 20px;
    color: #e67e22;
    transition: transform 0.3s ease;
}

.faq-item.active .question:after {
    content: '-';
    transform: rotate(180deg);
}

.faq-item .answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    font-size: 14px;
    color: #555;
    line-height: 1.7;
    padding-top: 0;
}

.faq-item.active .answer {
    max-height: 500px;
    padding-top: 15px;
}

/* 教程 */
.howto {
    background: #f0f4f8;
}

.howto-steps {
    max-width: 800px;
    margin: 0 auto;
}

.step {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
    align-items: flex-start;
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.6s ease;
}

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

.step .num {
    background: #e67e22;
    color: #fff;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
    transition: transform 0.3s ease;
}

.step:hover .num {
    transform: scale(1.1);
}

.step .content h4 {
    font-size: 18px;
    margin-bottom: 8px;
    color: #2c3e50;
}

.step .content p {
    font-size: 14px;
    color: #666;
}

/* 联系 */
.contact {
    background: linear-gradient(135deg, #2c3e50, #34495e);
    color: #fff;
}

.contact .grid {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.contact h3 {
    font-size: 18px;
    margin-bottom: 15px;
    color: #e67e22;
}

.contact p {
    font-size: 14px;
    margin-bottom: 8px;
    opacity: 0.9;
}

.contact a {
    color: #e67e22;
}

/* 页脚 */
.footer {
    background: #1a252f;
    color: #bbb;
    padding: 40px 0;
    font-size: 13px;
}

.footer .grid {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.footer h4 {
    color: #fff;
    margin-bottom: 15px;
    font-size: 16px;
}

.footer a {
    color: #bbb;
    display: block;
    margin-bottom: 6px;
    transition: color 0.3s ease;
}

.footer a:hover {
    color: #e67e22;
    padding-left: 5px;
}

.footer .copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid #2c3e50;
    margin-top: 30px;
    font-size: 12px;
}

/* 返回顶部 */
.back-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: #e67e22;
    color: #fff;
    width: 45px;
    height: 45px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    cursor: pointer;
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 999;
    box-shadow: 0 4px 15px rgba(230, 126, 34, 0.4);
}

.back-top.show {
    opacity: 1;
}

.back-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(230, 126, 34, 0.6);
}

/* 文章卡片 */
.articles .card .read-more {
    color: #e67e22;
    font-weight: 600;
    font-size: 13px;
}

.articles .card .date {
    font-size: 12px;
    color: #999;
    margin-bottom: 8px;
    display: block;
}

/* 滚动动画（默认隐藏，JS控制显示） */
.card, .testimonial, .step {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.card.visible, .testimonial.visible, .step.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 响应式布局 */
@media (max-width: 768px) {
    .nav {
        display: none;
    }

    .nav.active {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        background: rgba(44, 62, 80, 0.98);
        backdrop-filter: blur(10px);
        padding: 20px;
        gap: 15px;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    }

    .menu-btn {
        display: block;
    }

    .hero h1 {
        font-size: 28px;
    }

    .hero p {
        font-size: 16px;
    }

    .hero {
        padding: 60px 0;
    }

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

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

    .section-title {
        font-size: 26px;
    }

    .step {
        flex-direction: column;
    }

    .section {
        padding: 50px 0;
    }

    .card {
        padding: 20px;
    }

    .back-top {
        bottom: 20px;
        right: 20px;
        width: 40px;
        height: 40px;
        font-size: 18px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero h1 {
        font-size: 24px;
    }

    .hero p {
        font-size: 14px;
    }

    .about-stats {
        grid-template-columns: 1fr 1fr;
    }

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

    .stat .num {
        font-size: 28px;
    }
}