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

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: #1f2a37;
    background-color: #f5f7fa;
    overflow-x: hidden;
}

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

/* Header */
.header {
    background: linear-gradient(135deg, #111c2f, #1e2f4d);
    color: white;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 16px rgba(0,0,0,0.25);
}

.navbar {
    padding: 0.8rem 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-image {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid rgba(255,255,255,0.4);
}

.logo h1 {
    font-size: 1.4rem;
    font-weight: 700;
}

.logo-chinese {
    font-size: 0.85rem;
    opacity: 0.9;
    display: block;
}

.nav-menu {
    display: flex;
    list-style: none;
    align-items: center;
    gap: 1.5rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    position: relative;
    transition: color 0.3s ease;
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -6px;
    left: 0;
    background: #3fb1ff;
    transition: width 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: #3fb1ff;
}

.nav-link.active::after {
    width: 100%;
}

.lang-toggle {
    background: #3fb1ff;
    color: white;
    border: none;
    padding: 0.45rem 1rem;
    border-radius: 999px;
    cursor: pointer;
    font-weight: 600;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.hamburger .bar {
    width: 24px;
    height: 3px;
    background-color: white;
    margin: 3px 0;
    transition: 0.3s;
}

/* Section layout */
main {
    margin-top: 82px;
}

.section {
    display: none;
    min-height: calc(100vh - 82px);
    padding: 4rem 0;
}

.section.active {
    display: block !important;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.4rem;
    color: #111c2f;
    margin-bottom: 0.8rem;
}

.section-subtitle {
    color: #5f6c86;
    max-width: 640px;
    margin: 0 auto;
}

/* Overview */
.overview-section {
    background: radial-gradient(circle at top right, rgba(63,177,255,0.25), transparent 50%), #0f1729;
    color: white;
}

.hero-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 3rem;
    align-items: center;
}

.hero-content h2 {
    font-size: 2.8rem;
    margin: 0.5rem 0 1rem;
}

.hero-eyebrow {
    text-transform: uppercase;
    letter-spacing: 0.2em;
    font-size: 0.9rem;
    color: #8ac8ff;
}

.hero-description {
    color: rgba(255,255,255,0.85);
    margin-bottom: 1.5rem;
}

.hero-highlights {
    list-style: none;
    margin-bottom: 1.5rem;
}

.hero-highlights li {
    position: relative;
    padding-left: 1.4rem;
    margin-bottom: 0.8rem;
}

.hero-highlights li::before {
    content: '\2713';
    position: absolute;
    left: 0;
    color: #3fb1ff;
}

.hero-cta {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
    margin-bottom: 1.5rem;
}

.cta-button {
    background: linear-gradient(135deg, #3fb1ff, #0075ff);
    color: white;
    border: none;
    padding: 0.9rem 2rem;
    border-radius: 999px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(63,177,255,0.35);
}

.contact-pill {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.25);
    border-radius: 999px;
    padding: 0.6rem 1rem;
    font-weight: 600;
}

.hero-contact p {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin-bottom: 0.4rem;
    color: rgba(255,255,255,0.85);
}

.hero-contact i {
    color: #3fb1ff;
}

.hero-visual {
    background: rgba(255,255,255,0.05);
    border-radius: 24px;
    padding: 1.5rem;
    box-shadow: 0 30px 60px rgba(0,0,0,0.35);
}

.hero-visual img {
    border-radius: 18px;
}

/* Systems */
.systems-section {
    background: #f5f7fa;
}

.system-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.system-card {
    background: white;
    border-radius: 18px;
    box-shadow: 0 15px 35px rgba(15,23,41,0.08);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.system-image {
    height: 220px;
    overflow: hidden;
}

.system-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.system-body {
    padding: 1.8rem;
}

.system-body h3 {
    font-size: 1.4rem;
    color: #111c2f;
    margin-bottom: 0.8rem;
}

.system-body p {
    color: #5f6c86;
    margin-bottom: 1rem;
}

.system-specs {
    list-style: none;
}

.system-specs li {
    padding-left: 1.4rem;
    position: relative;
    margin-bottom: 0.6rem;
    color: #1f2a37;
}

.system-specs li::before {
    content: '\2022';
    position: absolute;
    left: 0;
    color: #3fb1ff;
}

/* Results */
.results-section {
    background: white;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.result-card {
    background: #0f1729;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 12px 30px rgba(15,23,41,0.25);
}

.result-card img {
    width: 100%;
    height: 180px;
    object-fit: cover;
}

.result-card figcaption {
    padding: 1rem;
    color: white;
    text-align: center;
    font-weight: 500;
}

/* Clients */
.clients-section {
    background: #f5f7fa;
}

.clients-layout {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 3rem;
    align-items: center;
}

.clients-text .section-header {
    text-align: left;
    margin-bottom: 1.5rem;
}

.client-points {
    list-style: none;
}

.client-points li {
    margin-bottom: 0.8rem;
    padding-left: 1.4rem;
    position: relative;
    color: #1f2a37;
}

.client-points li::before {
    content: '\25A0';
    position: absolute;
    left: 0;
    color: #3fb1ff;
}

.clients-visual img {
    border-radius: 18px;
    box-shadow: 0 20px 50px rgba(15,23,41,0.2);
}

/* Contact */
.contact-section {
    background: white;
}

.contact-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 3rem;
}

.contact-info h3,
.contact-form h3 {
    font-size: 1.5rem;
    color: #111c2f;
    margin-bottom: 1.5rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.contact-item i {
    color: #3fb1ff;
    font-size: 1.2rem;
}

.contact-item strong {
    color: #1f2a37;
}

.contact-item p {
    color: #5f6c86;
    margin: 0;
}

.wechat-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1rem;
}

.wechat-card {
    border: 1px solid #e4eaf5;
    border-radius: 14px;
    padding: 1rem;
    text-align: center;
    background: #f9fbff;
}

.wechat-card img {
    width: 100%;
    height: 200px;
    object-fit: contain;
}

.wechat-card p {
    margin-top: 0.6rem;
    color: #1f2a37;
    font-weight: 600;
}

.form-group {
    margin-bottom: 1.2rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.4rem;
    color: #1f2a37;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.85rem;
    border: 2px solid #e4eaf5;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.2s ease;
    background: #fdfefe;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #3fb1ff;
}

.submit-button {
    background: linear-gradient(135deg, #3fb1ff, #0075ff);
    color: white;
    border: none;
    padding: 0.9rem 2rem;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    width: 100%;
}

/* Footer */
.footer {
    background: #0b111f;
    color: white;
    padding: 3rem 0 1.5rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 0.8rem;
    color: #3fb1ff;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: rgba(255,255,255,0.75);
    text-decoration: none;
}

.footer-section p {
    color: rgba(255,255,255,0.7);
    margin-bottom: 0.4rem;
}

.social-links {
    display: flex;
    gap: 0.75rem;
}

.social-link {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255,255,255,0.12);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-decoration: none;
}

.footer-bottom {
    text-align: center;
    color: rgba(255,255,255,0.6);
    border-top: 1px solid rgba(255,255,255,0.08);
    padding-top: 1.2rem;
}

/* Responsive */
@media (max-width: 900px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: #0b111f;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .hamburger {
        display: flex;
    }

    .section {
        padding: 3rem 0;
    }
}

@media (max-width: 540px) {
    .nav-container,
    .container {
        padding: 0 1.2rem;
    }

    .hero-content h2 {
        font-size: 2.2rem;
    }

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

html {
    scroll-behavior: smooth;
}

.section.loading {
    opacity: 0;
    animation: fadeIn 0.45s ease forwards;
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}