:root {
    --color-light-bg: #eeeeee;
    --color-accent: #00adb5;
    --color-nav-bg: #3a4750;
    --color-dark: #303841;
    --color-white: #ffffff;
    --color-text: #333333;
    --color-text-light: #555555;
    --color-border: #dddddd;
    --max-width: 1200px;
    --nav-height: 68px;
    --transition-speed: 0.3s;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    background-color: var(--color-light-bg);
    color: var(--color-text);
    line-height: 1.7;
    min-width: 320px;
    overflow-x: hidden;
}

/* ========== 顶部导航 100%宽度 ========== */
.top-nav {
    width: 100%;
    background-color: var(--color-nav-bg);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.15);
    height: var(--nav-height);
}
.top-nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}
.nav-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    flex-shrink: 0;
    gap: 10px;
}
.nav-logo img {
    width: 44px;
    height: 44px;
    border-radius: 6px;
    object-fit: cover;
    flex-shrink: 0;
}
.nav-logo-text {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}
.nav-logo-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-white);
    white-space: nowrap;
    letter-spacing: 0.5px;
}
.nav-logo-sub {
    font-size: 0.7rem;
    color: var(--color-accent);
    white-space: nowrap;
    letter-spacing: 0.3px;
}
.nav-menu {
    display: flex;
    list-style: none;
    gap: 6px;
    align-items: center;
    flex-wrap: wrap;
    justify-content: flex-end;
}
.nav-menu li a {
    display: block;
    padding: 10px 16px;
    color: #d1d5db;
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: 4px;
    transition: all var(--transition-speed) ease;
    white-space: nowrap;
    letter-spacing: 0.3px;
    position: relative;
}
.nav-menu li a:hover,
.nav-menu li a.active {
    color: var(--color-white);
    background-color: rgba(0, 173, 181, 0.2);
}
.nav-menu li a.active::after {
    content: '';
    position: absolute;
    bottom: 4px;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 2px;
    background-color: var(--color-accent);
    border-radius: 1px;
}
.nav-cta-btn {
    background-color: var(--color-accent) !important;
    color: #ffffff !important;
    font-weight: 600 !important;
    padding: 10px 20px !important;
    border-radius: 6px !important;
    transition: all var(--transition-speed) ease !important;
}
.nav-cta-btn:hover {
    background-color: #009aa1 !important;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 173, 181, 0.35);
}

/* 汉堡菜单按钮 */
.hamburger-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    flex-direction: column;
    gap: 5px;
    z-index: 1001;
}
.hamburger-toggle span {
    display: block;
    width: 26px;
    height: 2.5px;
    background-color: var(--color-white);
    border-radius: 3px;
    transition: all var(--transition-speed) ease;
    transform-origin: center;
}
.hamburger-toggle.active span:nth-child(1) {
    transform: translateY(7.5px) rotate(45deg);
}
.hamburger-toggle.active span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}
.hamburger-toggle.active span:nth-child(3) {
    transform: translateY(-7.5px) rotate(-45deg);
}

/* 移动端菜单 */
@media (max-width: 900px) {
    .hamburger-toggle {
        display: flex;
    }
    .nav-menu {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background-color: var(--color-nav-bg);
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.4s ease, padding 0.4s ease;
        padding: 0 20px;
        box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
        z-index: 999;
    }
    .nav-menu.open {
        max-height: 500px;
        padding: 12px 20px;
    }
    .nav-menu li a {
        padding: 14px 16px;
        border-radius: 6px;
        text-align: center;
        font-size: 1rem;
    }
    .nav-cta-btn {
        margin-top: 4px;
    }
    .nav-logo-title {
        font-size: 0.9rem;
    }
    .nav-logo-sub {
        font-size: 0.65rem;
    }
}
@media (max-width: 480px) {
    .nav-logo img {
        width: 36px;
        height: 36px;
    }
    .nav-logo-title {
        font-size: 0.8rem;
    }
    .nav-logo-sub {
        font-size: 0.6rem;
    }
    .top-nav-inner {
        padding: 0 12px;
    }
}

/* ========== Hero 区域 ========== */
.hero-section {
    width: 100%;
    background: linear-gradient(160deg, #2c3a44 0%, var(--color-nav-bg) 40%, #2e3b45 100%);
    padding: 50px 20px 60px;
    position: relative;
    overflow: hidden;
}
.hero-section::before {
    content: '';
    position: absolute;
    top: -80px;
    right: -120px;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0, 173, 181, 0.12) 0%, transparent 70%);
    pointer-events: none;
}
.hero-section::after {
    content: '';
    position: absolute;
    bottom: -60px;
    left: -100px;
    width: 350px;
    height: 350px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0, 173, 181, 0.08) 0%, transparent 70%);
    pointer-events: none;
}
.hero-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 40px;
    position: relative;
    z-index: 1;
    flex-wrap: wrap;
}
.hero-text {
    flex: 1 1 400px;
    min-width: 280px;
}
.hero-badge {
    display: inline-block;
    background-color: rgba(0, 173, 181, 0.2);
    color: var(--color-accent);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    margin-bottom: 16px;
    border: 1px solid rgba(0, 173, 181, 0.3);
}
.hero-text h1 {
    font-size: 2.4rem;
    font-weight: 700;
    color: var(--color-white);
    line-height: 1.35;
    margin-bottom: 16px;
    letter-spacing: 0.5px;
}
.hero-text h1 .highlight {
    color: var(--color-accent);
    position: relative;
}
.hero-text .hero-desc {
    font-size: 1.1rem;
    color: #c5cdd5;
    margin-bottom: 28px;
    line-height: 1.6;
    max-width: 520px;
}
.hero-buttons {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}
.btn-primary {
    display: inline-block;
    background-color: var(--color-accent);
    color: #ffffff;
    padding: 13px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    letter-spacing: 0.4px;
    transition: all var(--transition-speed) ease;
    border: 2px solid var(--color-accent);
    cursor: pointer;
    text-align: center;
}
.btn-primary:hover {
    background-color: #009aa1;
    border-color: #009aa1;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 173, 181, 0.35);
}
.btn-outline {
    display: inline-block;
    background-color: transparent;
    color: var(--color-white);
    padding: 13px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    letter-spacing: 0.4px;
    transition: all var(--transition-speed) ease;
    border: 2px solid rgba(255, 255, 255, 0.5);
    cursor: pointer;
    text-align: center;
}
.btn-outline:hover {
    border-color: var(--color-white);
    background-color: rgba(255, 255, 255, 0.06);
    transform: translateY(-2px);
}
.hero-image-wrap {
    flex: 1 1 380px;
    min-width: 280px;
    display: flex;
    justify-content: center;
    align-items: center;
}
.hero-image-wrap img {
    width: 100%;
    max-width: 520px;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3);
    object-fit: cover;
    aspect-ratio: 16 / 10;
}
@media (max-width: 768px) {
    .hero-section {
        padding: 30px 16px 40px;
    }
    .hero-text h1 {
        font-size: 1.6rem;
    }
    .hero-text .hero-desc {
        font-size: 0.95rem;
    }
    .hero-inner {
        gap: 24px;
    }
    .btn-primary,
    .btn-outline {
        padding: 11px 22px;
        font-size: 0.9rem;
    }
    .hero-image-wrap img {
        max-width: 100%;
        aspect-ratio: 16 / 9;
    }
}
@media (max-width: 480px) {
    .hero-text h1 {
        font-size: 1.35rem;
    }
    .hero-text .hero-desc {
        font-size: 0.88rem;
    }
    .hero-buttons {
        flex-direction: column;
        gap: 10px;
    }
    .btn-primary,
    .btn-outline {
        width: 100%;
        text-align: center;
    }
}

/* ========== 通用区块 ========== */
.section {
    padding: 60px 20px;
    width: 100%;
}
.section-inner {
    max-width: var(--max-width);
    margin: 0 auto;
}
.section-header {
    text-align: center;
    margin-bottom: 44px;
}
.section-header .section-tag {
    display: inline-block;
    color: var(--color-accent);
    font-weight: 600;
    font-size: 0.85rem;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: 8px;
}
.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 10px;
    letter-spacing: 0.4px;
}
.section-header .section-subtitle {
    font-size: 1rem;
    color: #666;
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.5;
}
@media (max-width: 768px) {
    .section {
        padding: 40px 16px;
    }
    .section-header h2 {
        font-size: 1.5rem;
    }
}

/* ========== 服务卡片网格 ========== */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 24px;
}
.service-card {
    background-color: var(--color-white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
    transition: all var(--transition-speed) ease;
    display: flex;
    flex-direction: column;
    border: 1px solid var(--color-border);
}
.service-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.12);
    border-color: var(--color-accent);
}
.service-card-img {
    width: 100%;
    aspect-ratio: 16 / 10;
    object-fit: cover;
    display: block;
    background-color: #e8ecef;
}
.service-card-body {
    padding: 20px 22px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.service-card-body h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--color-dark);
    letter-spacing: 0.3px;
}
.service-card-body p {
    font-size: 0.9rem;
    color: #666;
    line-height: 1.5;
    flex-grow: 1;
}
.service-card-body .service-link {
    color: var(--color-accent);
    font-weight: 600;
    text-decoration: none;
    font-size: 0.9rem;
    align-self: flex-start;
    transition: color var(--transition-speed) ease;
    letter-spacing: 0.3px;
}
.service-card-body .service-link:hover {
    color: #009aa1;
    text-decoration: underline;
}
@media (max-width: 480px) {
    .services-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    .service-card-body {
        padding: 16px;
    }
}

/* ========== 优势区域 ========== */
.advantages-section {
    background-color: var(--color-white);
}
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 28px;
}
.advantage-item {
    text-align: center;
    padding: 28px 20px;
    border-radius: 10px;
    transition: all var(--transition-speed) ease;
    background-color: #fafbfc;
    border: 1px solid transparent;
}
.advantage-item:hover {
    border-color: var(--color-accent);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.06);
    background-color: #ffffff;
}
.advantage-icon-wrap {
    width: 64px;
    height: 64px;
    margin: 0 auto 16px;
    border-radius: 50%;
    background: linear-gradient(135deg, rgba(0, 173, 181, 0.12) 0%, rgba(0, 173, 181, 0.25) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}
.advantage-icon-wrap img {
    width: 36px;
    height: 36px;
    object-fit: contain;
}
.advantage-item h4 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 6px;
    letter-spacing: 0.3px;
}
.advantage-item p {
    font-size: 0.85rem;
    color: #777;
    line-height: 1.5;
}
@media (max-width: 480px) {
    .advantages-grid {
        grid-template-columns: 1fr 1fr;
        gap: 14px;
    }
    .advantage-item {
        padding: 18px 12px;
    }
    .advantage-icon-wrap {
        width: 48px;
        height: 48px;
    }
    .advantage-icon-wrap img {
        width: 28px;
        height: 28px;
    }
}

/* ========== 关于我们 ========== */
.about-section {
    background-color: var(--color-light-bg);
}
.about-flex {
    display: flex;
    gap: 40px;
    align-items: center;
    flex-wrap: wrap;
}
.about-image {
    flex: 1 1 350px;
    min-width: 260px;
    text-align: center;
}
.about-image img {
    width: 100%;
    max-width: 500px;
    height: auto;
    border-radius: 12px;
    object-fit: cover;
    aspect-ratio: 4 / 3;
    box-shadow: 0 8px 28px rgba(0, 0, 0, 0.1);
}
.about-text {
    flex: 1 1 380px;
    min-width: 260px;
}
.about-text h2 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 16px;
    letter-spacing: 0.4px;
}
.about-text p {
    font-size: 0.95rem;
    color: #555;
    line-height: 1.7;
    margin-bottom: 12px;
}
.about-text .highlight-text {
    color: var(--color-accent);
    font-weight: 600;
}
@media (max-width: 768px) {
    .about-flex {
        gap: 24px;
    }
    .about-text h2 {
        font-size: 1.4rem;
    }
}

/* ========== CTA横幅 ========== */
.cta-banner {
    width: 100%;
    background: linear-gradient(135deg, var(--color-nav-bg) 0%, var(--color-dark) 100%);
    padding: 50px 20px;
    text-align: center;
    position: relative;
    overflow: hidden;
}
.cta-banner::before {
    content: '';
    position: absolute;
    top: -50px;
    right: -50px;
    width: 250px;
    height: 250px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0, 173, 181, 0.15) 0%, transparent 70%);
    pointer-events: none;
}
.cta-banner-inner {
    max-width: 700px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}
.cta-banner h2 {
    font-size: 1.8rem;
    color: var(--color-white);
    font-weight: 700;
    margin-bottom: 12px;
    letter-spacing: 0.4px;
}
.cta-banner p {
    color: #c5cdd5;
    font-size: 1rem;
    margin-bottom: 24px;
}
.cta-banner .btn-primary {
    font-size: 1.05rem;
    padding: 14px 32px;
}
@media (max-width: 480px) {
    .cta-banner h2 {
        font-size: 1.35rem;
    }
}

/* ========== 底部导航 100%宽度 ========== */
.footer-nav {
    width: 100%;
    background-color: var(--color-dark);
    color: #c5cdd5;
    padding: 48px 20px 24px;
}
.footer-nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 32px;
}
.footer-col h4 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: 14px;
    letter-spacing: 0.4px;
    position: relative;
    padding-bottom: 10px;
}
.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background-color: var(--color-accent);
    border-radius: 1px;
}
.footer-col ul {
    list-style: none;
    padding: 0;
}
.footer-col ul li {
    margin-bottom: 8px;
}
.footer-col ul li a {
    color: #a8b2bb;
    text-decoration: none;
    font-size: 0.9rem;
    transition: color var(--transition-speed) ease;
    letter-spacing: 0.2px;
}
.footer-col ul li a:hover {
    color: var(--color-accent);
}
.footer-col .footer-contact-item {
    font-size: 0.88rem;
    color: #a8b2bb;
    margin-bottom: 6px;
    line-height: 1.5;
}
.footer-bottom {
    max-width: var(--max-width);
    margin: 28px auto 0;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    font-size: 0.82rem;
    color: #88929b;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 16px;
    align-items: center;
}
.footer-bottom a {
    color: var(--color-accent);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-speed) ease;
}
.footer-bottom a:hover {
    color: #ffffff;
}
.mobile-link-highlight {
    display: inline-block;
    background-color: rgba(0, 173, 181, 0.15);
    padding: 6px 14px;
    border-radius: 20px;
    border: 1px solid rgba(0, 173, 181, 0.3);
    font-weight: 600;
    letter-spacing: 0.3px;
    transition: all var(--transition-speed) ease;
}
.mobile-link-highlight:hover {
    background-color: rgba(0, 173, 181, 0.3);
    border-color: var(--color-accent);
}
@media (max-width: 480px) {
    .footer-nav-inner {
        grid-template-columns: 1fr 1fr;
        gap: 20px;
    }
    .footer-bottom {
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }
}

/* ========== 返回顶部按钮 ========== */
.back-to-top {
    position: fixed;
    bottom: 28px;
    right: 28px;
    width: 44px;
    height: 44px;
    background-color: var(--color-accent);
    color: #ffffff;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    font-weight: 700;
    z-index: 900;
    box-shadow: 0 4px 14px rgba(0, 173, 181, 0.35);
    transition: all var(--transition-speed) ease;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    letter-spacing: 0;
    line-height: 1;
}
.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.back-to-top:hover {
    background-color: #009aa1;
    transform: translateY(-4px);
    box-shadow: 0 8px 22px rgba(0, 173, 181, 0.45);
}
@media (max-width: 480px) {
    .back-to-top {
        bottom: 16px;
        right: 16px;
        width: 38px;
        height: 38px;
        font-size: 1rem;
    }
}