/* ========================================
   同顺源建设 - 仿深圳建设集团风格
   ======================================== */

/* CSS Variables */
:root {
    --primary-color: #c41e3a;
    --primary-dark: #a01830;
    --primary-light: #e03050;
    --text-dark: #333333;
    --text-gray: #666666;
    --text-light: #999999;
    --bg-white: #ffffff;
    --bg-gray: #f5f5f5;
    --border-color: #e8e8e8;
    --transition: all 0.3s ease;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
}

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

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

ul {
    list-style: none;
}

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

/* ========================================
   Header / Navigation - 增大字号
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: var(--bg-white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    height: 90px;
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

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

.logo a {
    display: flex;
    align-items: center;
    gap: 18px;
}

.logo img {
    height: 65px;
    width: auto;
}

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

.logo-name {
    font-size: 26px;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: 2px;
}

.logo-en {
    font-size: 12px;
    color: var(--text-light);
    letter-spacing: 1px;
    text-transform: uppercase;
}

.nav-list {
    display: flex;
    gap: 55px;
}

.nav-list a {
    font-size: 18px;
    color: var(--text-dark);
    position: relative;
    padding: 5px 0;
}

.nav-list a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.nav-list a:hover,
.nav-list a.active {
    color: var(--primary-color);
}

.nav-list a:hover::after,
.nav-list a.active::after {
    width: 100%;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 30px;
}

.search-icon {
    cursor: pointer;
    color: var(--text-gray);
    transition: var(--transition);
}

.search-icon:hover {
    color: var(--primary-color);
}

.header-btn {
    padding: 10px 24px;
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    font-size: 16px;
    border-radius: 4px;
    transition: var(--transition);
}

.header-btn:hover {
    background-color: var(--primary-color);
    color: var(--bg-white);
}

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

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--text-dark);
}

/* ========================================
   Banner Section - 带切换功能
   ======================================== */
.banner {
    position: relative;
    height: 100vh;
    min-height: 700px;
    overflow: hidden;
}

.banner-slider {
    position: relative;
    width: 100%;
    height: 100%;
}

.banner-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    opacity: 0;
    transition: opacity 0.8s ease;
}

.banner-slide.active {
    opacity: 1;
}

.banner-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(0,0,0,0.4) 0%, rgba(0,0,0,0.6) 100%);
}

.banner-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: var(--bg-white);
    z-index: 2;
    width: 90%;
    max-width: 1000px;
}

.banner-title {
    font-size: 52px;
    font-weight: 700;
    letter-spacing: 8px;
    margin-bottom: 25px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}

.banner-subtitle {
    font-size: 26px;
    font-weight: 300;
    letter-spacing: 4px;
    opacity: 0.9;
}

.banner-categories {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: center;
    z-index: 2;
    background: rgba(0,0,0,0.4);
    backdrop-filter: blur(5px);
}

.category-item {
    flex: 1;
    max-width: 220px;
    padding: 28px 20px;
    text-align: center;
    color: var(--bg-white);
    border-right: 1px solid rgba(255,255,255,0.2);
    cursor: pointer;
    transition: var(--transition);
}

.category-item:last-child {
    border-right: none;
}

.category-item:hover,
.category-item.active {
    background-color: var(--primary-color);
}

.category-item span {
    font-size: 18px;
    letter-spacing: 2px;
}

/* ========================================
   Section Header
   ======================================== */
.section-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 50px;
}

.section-header.center {
    justify-content: center;
}

.section-icon {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--primary-color);
    color: var(--bg-white);
    border-radius: 4px;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--primary-color);
}

/* ========================================
   Services Section
   ======================================== */
.services {
    padding: 100px 0;
    background-color: var(--bg-gray);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.service-card {
    background-color: var(--bg-white);
    padding: 45px 30px;
    text-align: center;
    border-radius: 4px;
    transition: var(--transition);
    border: 1px solid var(--border-color);
    display: block;
}

.service-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-5px);
    border-color: var(--primary-color);
}

.service-icon {
    color: var(--primary-color);
    margin-bottom: 25px;
}

.service-name {
    font-size: 22px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 15px;
}

.service-desc {
    font-size: 15px;
    color: var(--text-gray);
    line-height: 1.6;
}

.service-link {
    display: inline-block;
    margin-top: 20px;
    color: var(--primary-color);
    font-size: 15px;
    font-weight: 500;
}

.ai-card {
    position: relative;
}

.ai-card::before {
    content: 'AI';
    position: absolute;
    top: 15px;
    right: 15px;
    background-color: var(--primary-color);
    color: var(--bg-white);
    font-size: 12px;
    font-weight: 700;
    padding: 5px 12px;
    border-radius: 4px;
}

/* ========================================
   Projects Section - 网格布局
   ======================================== */
.projects {
    padding: 100px 0;
    background-color: var(--bg-white);
}

.projects-filter {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 50px;
}

.filter-btn {
    padding: 10px 25px;
    background: none;
    border: none;
    font-size: 16px;
    color: var(--text-gray);
    cursor: pointer;
    transition: var(--transition);
    border-bottom: 2px solid transparent;
}

.filter-btn:hover,
.filter-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.project-card {
    background-color: var(--bg-white);
    border-radius: 4px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.project-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-5px);
}

.project-image {
    position: relative;
    height: 220px;
    overflow: hidden;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(196, 30, 58, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-view {
    color: var(--bg-white);
    font-size: 16px;
    font-weight: 500;
}

.project-info {
    padding: 25px;
}

.project-category {
    font-size: 13px;
    color: var(--primary-color);
    margin-bottom: 10px;
    display: block;
}

.project-name {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 8px;
}

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

.projects-more {
    text-align: center;
    margin-top: 50px;
}

.btn-outline {
    display: inline-block;
    padding: 14px 40px;
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    font-size: 16px;
    font-weight: 500;
    border-radius: 4px;
    transition: var(--transition);
}

.btn-outline:hover {
    background-color: var(--primary-color);
    color: var(--bg-white);
}

/* ========================================
   About Section (业务承接)
   ======================================== */
.about {
    padding: 100px 0;
    background-color: var(--bg-gray);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    margin-bottom: 60px;
}

.about-left {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.about-main-title {
    font-size: 46px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 15px;
    line-height: 1.3;
}

.about-subtitle {
    font-size: 26px;
    color: var(--primary-color);
    font-weight: 500;
}

.about-right {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.about-desc {
    font-size: 17px;
    color: var(--text-gray);
    line-height: 1.8;
    margin-bottom: 20px;
}

.about-more {
    display: inline-block;
    margin-top: 10px;
    color: var(--primary-color);
    font-size: 17px;
    font-weight: 500;
}

.about-more:hover {
    color: var(--primary-dark);
}

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

.about-img-item {
    height: 220px;
    overflow: hidden;
    border-radius: 4px;
}

.about-img-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.about-img-item:hover img {
    transform: scale(1.05);
}

/* ========================================
   Contact Section
   ======================================== */
.contact {
    padding: 100px 0;
    background-color: var(--bg-white);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 35px;
}

.contact-item {
    display: flex;
    gap: 20px;
    align-items: flex-start;
}

.contact-icon {
    width: 55px;
    height: 55px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--primary-color);
    color: var(--bg-white);
    border-radius: 4px;
    flex-shrink: 0;
}

.contact-detail h4 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 12px;
}

.contact-detail p {
    font-size: 17px;
    color: var(--text-gray);
    line-height: 1.8;
}

/* 联系二维码区域 */
.contact-qr-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-gray);
    padding: 50px;
    border-radius: 4px;
}

.contact-qr-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 30px;
}

.contact-qr-img {
    width: 200px;
    height: 200px;
    margin-bottom: 20px;
}

.contact-qr-img img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.contact-qr-text {
    font-size: 16px;
    color: var(--text-gray);
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background-color: var(--bg-white);
}

.footer-top {
    padding: 60px 0;
    border-top: 1px solid var(--border-color);
}

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

.footer-nav {
    display: flex;
    gap: 55px;
}

.footer-nav a {
    font-size: 18px;
    color: var(--text-dark);
    font-weight: 500;
}

.footer-nav a:hover {
    color: var(--primary-color);
}

.footer-qr {
    text-align: center;
}

.footer-qr img {
    width: 110px;
    height: 110px;
    margin-bottom: 10px;
    border-radius: 4px;
}

.footer-qr p {
    font-size: 15px;
    color: var(--text-gray);
}

.footer-bottom {
    padding: 25px 0;
    background-color: var(--bg-gray);
    border-top: 1px solid var(--border-color);
}

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

.footer-links {
    display: flex;
    gap: 35px;
}

.footer-links a {
    font-size: 15px;
    color: var(--text-gray);
}

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

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

/* ========================================
   Floating Contact
   ======================================== */
.floating-contact {
    position: fixed;
    right: 30px;
    bottom: 100px;
    z-index: 999;
}

.floating-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 16px 26px;
    background-color: var(--primary-color);
    color: var(--bg-white);
    border-radius: 30px;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(196, 30, 58, 0.4);
    transition: var(--transition);
    font-size: 16px;
    font-weight: 500;
}

.floating-btn:hover {
    background-color: var(--primary-dark);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(196, 30, 58, 0.5);
}

.contact-popup {
    position: absolute;
    right: 0;
    bottom: 75px;
    width: 300px;
    background-color: var(--bg-white);
    border-radius: 8px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    padding: 30px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: var(--transition);
}

.floating-contact:hover .contact-popup {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.popup-header {
    text-align: center;
    margin-bottom: 20px;
}

.popup-header h4 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 5px;
}

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

.popup-qr {
    text-align: center;
    margin-bottom: 20px;
}

.popup-qr img {
    width: 200px;
    height: 200px;
    border-radius: 8px;
}

.popup-phone {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.popup-phone p {
    font-size: 16px;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.popup-phone a {
    color: var(--primary-color);
    font-weight: 500;
}

.popup-phone a:hover {
    text-decoration: underline;
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 1024px) {
    .header-container {
        padding: 0 20px;
    }
    
    .nav-list {
        gap: 35px;
    }
    
    .nav-list a {
        font-size: 16px;
    }
    
    .banner-title {
        font-size: 42px;
    }
    
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .header {
        height: 70px;
    }
    
    .logo img {
        height: 45px;
    }
    
    .logo-name {
        font-size: 20px;
    }
    
    .nav {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .header-right {
        display: none;
    }
    
    .banner-title {
        font-size: 28px;
        letter-spacing: 4px;
    }
    
    .banner-subtitle {
        font-size: 18px;
    }
    
    .banner-categories {
        flex-wrap: wrap;
    }
    
    .category-item {
        flex: 0 0 50%;
        max-width: none;
        border-right: none;
        border-bottom: 1px solid rgba(255,255,255,0.2);
        padding: 18px 15px;
    }
    
    .category-item span {
        font-size: 15px;
    }
    
    .about-main-title {
        font-size: 28px;
    }
    
    .about-subtitle {
        font-size: 18px;
    }
    
    .about-images {
        grid-template-columns: 1fr;
    }
    
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .projects-filter {
        flex-wrap: wrap;
        gap: 15px;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-qr-wrapper {
        padding: 30px 20px;
    }
    
    .contact-qr-title {
        font-size: 22px;
    }
    
    .footer-top .container {
        flex-direction: column;
        gap: 30px;
    }
    
    .footer-nav {
        flex-wrap: wrap;
        justify-content: center;
        gap: 25px;
    }
    
    .footer-nav a {
        font-size: 16px;
    }
    
    .footer-bottom .container {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }
    
    .floating-contact {
        right: 15px;
        bottom: 80px;
    }
    
    .floating-btn span {
        display: none;
    }
    
    .floating-btn {
        padding: 14px;
        border-radius: 50%;
    }
    
    .contact-popup {
        width: 260px;
        right: -10px;
    }
    
    .popup-qr img {
        width: 160px;
        height: 160px;
    }
}