/* --- 全局样式 --- */
:root {
    --primary-color: #00ff7f; /* 亮绿色，荧光感 */
    --background-color: #0d0d0d; /* 深黑色背景 */
    --text-color: #e0e0e0; /* 浅灰色文字 */
    --container-bg-color: #1a1a1a; /* 区块背景色 */
    --border-color: #2a2a2a; /* 边框颜色 */
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

h1, h2, h3 {
    color: var(--primary-color);
    font-weight: 500;
}

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

.section {
    padding: 60px 0;
}

.section-title {
    text-align: center;
    font-size: 2.5em;
    margin-bottom: 40px;
    text-transform: uppercase;
    letter-spacing: 2px;
}

/* --- Header --- */
.header {
    background-color: var(--container-bg-color);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

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

.logo h1 a {
    font-size: 1.8em;
    color: var(--primary-color);
}

.nav ul {
    list-style: none;
    display: flex;
}

.nav ul li {
    margin-left: 25px;
}

.nav ul li a {
    color: var(--text-color);
    font-size: 1.1em;
    transition: color 0.3s ease;
}

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

.menu-toggle {
    display: none;
    cursor: pointer;
}

.menu-toggle span {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    margin: 5px 0;
}

/* --- Hero Section --- */
.hero {
    display: flex;
    align-items: center;
    min-height: 70vh;
    background: var(--background-color) url('https://www.transparenttextures.com/patterns/carbon-fibre.png');
    padding: 40px 0;
}

.hero .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 40px;
}

.hero-content {
    flex: 1;
    text-align: left;
}

.hero h2 {
    font-size: 3em;
    margin-bottom: 20px;
}

.hero p {
    font-size: 1.2em;
    margin-bottom: 30px;
}

.hero-image {
    flex: 0 0 320px;
    text-align: center;
}

.hero-image img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    border: 2px solid var(--primary-color);
    padding: 10px;
    background: #fff;
}

.hero-image .image-caption {
    margin-top: 15px;
    font-size: 1.1em;
    color: var(--primary-color);
    font-weight: bold;
}

.cta-button {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--background-color);
    padding: 12px 25px;
    border-radius: 5px;
    font-weight: bold;
    text-transform: uppercase;
    transition: background-color 0.3s ease, transform 0.3s ease;
}

.cta-button:hover {
    background-color: #fff;
    transform: translateY(-3px);
}


/* --- Services Section --- */
.services-section {
    background-color: var(--container-bg-color);
}

.service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.service-item {
    background: var(--background-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.service-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 0 20px rgba(0, 255, 127, 0.5);
}

.service-item-header {
    padding: 15px 20px;
    border-bottom: 1px solid var(--border-color);
    background-color: #111;
}

.service-item-header h3 {
    font-size: 1.4em;
    margin: 0;
    color: var(--primary-color);
}

.service-item-body {
    padding: 20px;
    flex-grow: 1;
}

.service-item-body p {
    margin: 0;
    font-size: 1em;
}

/* --- Advantages Section --- */
.advantages-section {
    background-color: var(--background-color);
}
.advantage-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}
.advantage-item {
    background-color: var(--container-bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}
.advantage-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 0 15px rgba(0, 255, 127, 0.4);
}
.advantage-item-header {
    padding: 12px 20px;
    background-color: #222;
    border-bottom: 1px solid var(--border-color);
}
.advantage-item-header h3 {
    font-size: 1.3em;
    margin: 0;
}
.advantage-item-body {
    padding: 20px;
    flex-grow: 1;
}
.advantage-item-body p {
    margin: 0;
    font-size: 1em;
}

/* --- Process Section --- */
.process-section {
    background-color: var(--container-bg-color);
}
.process-steps {
    display: flex;
    justify-content: space-between;
    gap: 30px;
    text-align: center;
}

/* --- Process Card Style --- */
.process-item {
    background-color: var(--background-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    width: 23%;
    position: relative;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.process-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 0 15px rgba(0, 255, 127, 0.4);
}
.process-item-header {
    padding: 15px 20px;
    background-color: #222;
    border-bottom: 1px solid var(--border-color);
}
.process-item-header h4 {
    font-size: 1.2em;
    margin: 0;
    color: var(--primary-color);
}
.process-item-body {
    padding: 20px;
    flex-grow: 1;
}
.process-item-body p {
    margin: 0;
    font-size: 1em;
}
.process-item:not(:last-child)::after {
    content: '→';
    color: var(--primary-color);
    position: absolute;
    right: -26px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 2.5em;
    font-weight: bold;
}

/* --- FAQ Section --- */
.faq-section {
    background-color: var(--background-color);
}
.faq-item {
    max-width: 800px;
    margin: 0 auto 20px auto;
    background: var(--container-bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.faq-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 0 15px rgba(0, 255, 127, 0.4);
}
.faq-item-header {
    padding: 15px 20px;
    background-color: #222;
    border-bottom: 1px solid var(--border-color);
}
.faq-item-header h4 {
    font-size: 1.1em;
    margin: 0;
    color: var(--primary-color);
}
.faq-item-body {
    padding: 20px;
    flex-grow: 1;
}
.faq-item-body p {
    margin: 0;
    font-size: 1em;
}
.faq-item:last-child {
    margin-bottom: 0;
}

/* --- Pricing & About Sections --- */
#pricing p {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.1em;
}

/* --- Pricing Card --- */
.pricing-card {
    max-width: 800px;
    margin: 0 auto;
    background: var(--container-bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    text-align: left;
}
.pricing-card-header {
    padding: 15px 20px;
    background-color: #222;
    border-bottom: 1px solid var(--border-color);
}
.pricing-card-header h3 {
    font-size: 1.3em;
    margin: 0;
    color: var(--primary-color);
}
.pricing-card-body {
    padding: 30px;
}
.pricing-card-body p {
    margin-bottom: 30px;
    font-size: 1.1em;
    text-align: left;
}

/* --- Footer --- */
.footer {
    background-color: #000;
    text-align: center;
    padding: 30px 0;
    border-top: 1px solid var(--border-color);
    font-size: 0.9em;
}

.footer .container {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.friend-links h3 {
    margin-bottom: 15px;
    font-size: 1.2em;
}

.friend-links ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
}

.friend-links ul li a {
    color: var(--text-color);
    transition: color 0.3s ease;
}

.friend-links ul li a:hover {
    color: var(--primary-color);
}

.copyright p {
    margin: 5px 0;
}

/* --- Responsive Design --- */
@media (max-width: 768px) {
    .logo h1 a {
        font-size: 1.4em;
    }

    .header .container {
        flex-wrap: wrap;
        justify-content: space-between;
    }

    .menu-toggle {
        display: block;
    }

    .nav {
        display: none; /* Hide nav by default on mobile */
        width: 100%;
        order: 3; /* Ensure it appears below logo and toggle */
        margin-top: 15px;
        text-align: center;
    }

    .nav.active {
        display: block; /* Show nav when active */
    }

    .nav ul {
        flex-direction: column;
    }

    .nav ul li {
        margin: 10px 0;
        margin-left: 0;
    }

    .nav ul li a {
        font-size: 1.2em;
    }

    .hero .container {
        flex-direction: column;
    }

    .hero-content {
        text-align: center;
        margin-bottom: 40px;
    }

    .hero h2 {
        font-size: 2.2em;
    }

    .process-steps {
        flex-direction: column;
    }
    .process-item {
        width: 100%;
        margin-bottom: 40px;
    }
    .process-item:last-child {
        margin-bottom: 0;
    }
    .process-item:not(:last-child)::after {
        content: '↓';
        right: 50%;
        top: 100%;
        transform: translateX(50%) translateY(0);
        line-height: 1;
    }
}