/* ============ RESET & BASE ============ */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #00d4ff;
    --primary-dark: #0099cc;
    --bg-dark: #0a0e1a;
    --bg-darker: #060a14;
    --bg-card: rgba(15, 23, 42, 0.8);
    --text-primary: #f0f4ff;
    --text-secondary: #94a3b8;
    --glow: rgba(0, 212, 255, 0.3);
    --gradient: linear-gradient(135deg, #00d4ff, #0066ff);
}

html {
    scroll-behavior: smooth;
    /* 禁用顶部弹性回弹，防止惯性滑动时露出浏览器白色画布 */
    overscroll-behavior-y: none;
    /* 深色画布底，避免滚动回弹时顶部闪白线 */
    background-color: var(--bg-dark);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.7;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
}

/* ============ CANVAS BACKGROUND ============ */
#particles-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
}

/* ============ NAVBAR ============ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1rem 0;
    /* 常态即深色实底：弹性回弹时导航被顶起也始终盖住顶部缝隙，白底不可见 */
    background: rgba(10, 14, 26, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 212, 255, 0.1);
    transition: padding 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}


.navbar.scrolled {
    padding: 0.6rem 0;
    border-bottom: 1px solid rgba(0, 212, 255, 0.1);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

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

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    font-weight: 800;
    font-size: 1.35rem;
}

.nav-logo-img {
    width: 52px;
    height: 52px;
    object-fit: contain;
    border-radius: 8px;
}

.logo-icon {
    font-size: 1.6rem;
    color: var(--primary);
}

.logo-text small {
    display: block;
    font-size: 1.05rem;
    color: var(--text-primary);
    font-weight: 700;
    letter-spacing: 4px;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
}

.nav-link {
    color: var(--text-secondary);
    font-size: 0.95rem;
    transition: color 0.3s;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    transition: width 0.3s ease;
}

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

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

.lang-toggle {
    background: transparent;
    border: none;
    color: var(--text-primary);
    padding: 0.45rem 0.35rem;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 1px;
    cursor: pointer;
    margin: 0 1rem;
    transition: background 0.25s ease, color 0.25s ease;
}

.lang-toggle:hover {
    background: rgba(0, 212, 255, 0.08);
    color: var(--primary);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--primary);
    transition: 0.3s;
}

/* ============ HERO ============ */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    z-index: 1;
    padding: 2rem;
}

.hero-content {
    max-width: 900px;
    animation: fadeInUp 1s ease-out;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.2rem);
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.gradient-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    line-height: 1.8;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 1.2rem;
    justify-content: center;
    margin-bottom: 4rem;
}

.btn {
    padding: 0.85rem 2.2rem;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-block;
    border: none;
}

.btn-primary {
    background: var(--gradient);
    color: #fff;
    box-shadow: 0 4px 20px var(--glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px var(--glow);
}

.btn-outline {
    background: transparent;
    border: 1.5px solid var(--primary);
    color: var(--primary);
}

.btn-outline:hover {
    background: rgba(0, 212, 255, 0.1);
    transform: translateY(-2px);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 3.5rem;
    flex-wrap: wrap;
}

.stat-item {
    text-align: center;
}

.stat-number, .stat-suffix {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary);
}

.stat-label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 0.3rem;
}

.scroll-indicator {
    position: absolute;
    bottom: 2.5rem;
    left: 50%;
    transform: translateX(-50%);
}

.scroll-mouse {
    width: 26px;
    height: 42px;
    border: 2px solid var(--text-secondary);
    border-radius: 13px;
    position: relative;
}

.scroll-mouse::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 3px;
    height: 8px;
    background: var(--primary);
    border-radius: 2px;
    animation: scrollAnim 1.5s infinite;
}

/* ============ SECTIONS ============ */
.section {
    padding: 6rem 0;
    position: relative;
    z-index: 1;
}

.section-dark {
    background: transparent;
}

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

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-tag {
    display: inline-block;
    font-size: 0.8rem;
    letter-spacing: 3px;
    color: var(--primary);
    background: rgba(0, 212, 255, 0.08);
    padding: 0.3rem 1rem;
    border-radius: 20px;
    border: 1px solid rgba(0, 212, 255, 0.15);
    margin-bottom: 1rem;
}

.section-title {
    font-size: clamp(1.8rem, 4vw, 2.6rem);
    font-weight: 700;
    margin-bottom: 0.8rem;
}

.section-desc {
    color: var(--text-secondary);
    font-size: 1.05rem;
    max-width: 600px;
    margin: 0 auto;
}

/* ============ ABOUT ============ */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
}

.about-text {
    color: var(--text-secondary);
    line-height: 1.9;
    font-size: 0.98rem;
}

.about-text p {
    margin-bottom: 1.2rem;
}

.about-text b {
    color: var(--primary);
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.2rem;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid rgba(0, 212, 255, 0.08);
    border-radius: 12px;
    padding: 1.5rem;
    transition: all 0.3s ease;
}

.feature-card:hover {
    border-color: rgba(0, 212, 255, 0.25);
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0, 212, 255, 0.08);
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 0.8rem;
}

.feature-card h4 {
    font-size: 1rem;
    margin-bottom: 0.4rem;
}

.feature-card p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ============ PRODUCTS ============ */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
}

.product-card-expandable {
    grid-column: 1 / -1;
}

.product-card-header {
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.product-card-top {
    display: flex;
    align-items: flex-start;
    gap: 1.2rem;
    flex: 1;
}

.product-desc {
    font-size: 0.92rem;
    color: var(--text-secondary);
    margin-top: 0.4rem;
}

.expand-indicator {
    font-size: 0.82rem;
    color: var(--primary);
    white-space: nowrap;
}

/* 平滑展开/收起：用 grid 0fr -> 1fr 精确动画高度，避免 max-height 卡顿 */
.product-spec-panel {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.45s cubic-bezier(0.4, 0, 0.2, 1),
                margin 0.45s cubic-bezier(0.4, 0, 0.2, 1),
                border-color 0.45s ease;
    margin-top: 0;
    border-top: 1px solid transparent;
}

.spec-panel-inner {
    min-height: 0;
    overflow: hidden;
}

.spec-panel-inner .spec-header {
    margin-top: 1.5rem;
}

.product-card-expandable.expanded .product-spec-panel {
    grid-template-rows: 1fr;
    margin-top: 1.5rem;
    border-top-color: rgba(0, 212, 255, 0.1);
}

.spec-header {
    margin-bottom: 1.2rem;
}

.spec-header h4 {
    font-size: 1.1rem;
    margin-bottom: 0.3rem;
}

.spec-meta {
    font-size: 0.82rem;
    color: var(--text-secondary);
}

.spec-table-wrap {
    overflow-x: auto;
    border-radius: 10px;
    border: 1px solid rgba(0, 212, 255, 0.1);
}

.spec-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
    min-width: 700px;
}

.spec-table thead th {
    background: rgba(0, 212, 255, 0.08);
    color: var(--primary);
    padding: 0.7rem 0.9rem;
    text-align: center;
    font-weight: 600;
    border-bottom: 2px solid rgba(0, 212, 255, 0.15);
}

.spec-table tbody td {
    padding: 0.55rem 0.9rem;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.spec-table tbody td:first-child {
    text-align: left;
    font-weight: 500;
    white-space: nowrap;
}

.spec-table tbody tr:hover {
    background: rgba(0, 212, 255, 0.03);
}

.spec-group td {
    background: rgba(0, 212, 255, 0.05) !important;
    font-weight: 700;
    color: var(--primary);
    text-align: left !important;
    padding: 0.45rem 0.9rem;
    font-size: 0.8rem;
    letter-spacing: 1px;
}

.spec-note {
    margin-top: 1rem;
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.spec-empty {
    text-align: center !important;
    padding: 2rem !important;
    color: var(--text-secondary);
    font-style: italic;
}

.product-card {
    background: var(--bg-card);
    border: 1px solid rgba(0, 212, 255, 0.08);
    border-radius: 16px;
    padding: 2rem;
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}

.product-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient);
    opacity: 0;
    transition: opacity 0.3s;
}

.product-card:hover {
    border-color: rgba(0, 212, 255, 0.3);
    transform: translateY(-6px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3), 0 0 30px var(--glow);
}

.product-card:hover::before {
    opacity: 1;
}

.product-card h3 {
    font-size: 1.2rem;
    margin-bottom: 0.8rem;
}

.product-card p {
    color: var(--text-secondary);
    font-size: 0.92rem;
    line-height: 1.7;
    margin-bottom: 1rem;
}

.product-tag {
    display: inline-block;
    font-size: 0.78rem;
    padding: 0.25rem 0.8rem;
    border-radius: 20px;
    background: rgba(0, 212, 255, 0.08);
    color: var(--primary);
    border: 1px solid rgba(0, 212, 255, 0.15);
}

/* ============ INDUSTRIES ============ */
.industries-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.industry-item {
    text-align: center;
    padding: 2rem 1.5rem;
    background: var(--bg-card);
    border: 1px solid rgba(0, 212, 255, 0.06);
    border-radius: 14px;
    transition: all 0.3s ease;
}

.industry-item:hover {
    border-color: rgba(0, 212, 255, 0.2);
    box-shadow: 0 8px 25px rgba(0, 212, 255, 0.06);
}

.industry-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.industry-item h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.industry-item p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ============ ADVANTAGES ============ */
.advantages {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.advantage-item {
    position: relative;
    padding: 2rem 1.5rem;
    background: rgba(0, 212, 255, 0.03);
    border-left: 3px solid var(--primary);
    border-radius: 0 12px 12px 0;
}

.advantage-num {
    font-size: 2.5rem;
    font-weight: 800;
    color: rgba(0, 212, 255, 0.15);
    position: absolute;
    top: 1rem;
    right: 1.2rem;
}

.advantage-item h4 {
    font-size: 1.1rem;
    margin-bottom: 0.6rem;
    color: var(--primary);
}

.advantage-item p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============ CONTACT ============ */
.contact-grid {
    display: flex;
    justify-content: center;
}

.contact-info {
    max-width: 760px;
    width: 100%;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

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

.contact-icon {
    font-size: 1.5rem;
    min-width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 212, 255, 0.08);
    border-radius: 10px;
}

.contact-item h4 {
    font-size: 0.95rem;
    margin-bottom: 0.2rem;
}

.contact-item p {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* ============ FOOTER ============ */
.footer {
    position: relative;
    z-index: 1;
    background: var(--bg-darker);
    border-top: 1px solid rgba(0, 212, 255, 0.08);
    padding: 4rem 0 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 3rem;
    padding-bottom: 3rem;
}

.footer-brand .logo-icon {
    font-size: 1.4rem;
}

.footer-brand h3 {
    margin: 0.8rem 0 0.5rem;
    font-size: 1.3rem;
}

.footer-brand p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.7;
}

.footer-links h4 {
    margin-bottom: 1rem;
    font-size: 0.95rem;
    color: var(--primary);
}

.footer-links a {
    display: block;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.6rem;
    transition: color 0.3s;
}

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

.footer-bottom {
    border-top: 1px solid rgba(0, 212, 255, 0.06);
    padding: 1.5rem 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.82rem;
    color: var(--text-secondary);
    opacity: 0.7;
}

/* ============ ANIMATIONS ============ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes scrollAnim {
    0% { opacity: 1; top: 8px; }
    100% { opacity: 0; top: 24px; }
}

/* Scroll reveal */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* ============ RESPONSIVE ============ */
@media (max-width: 968px) {
    .about-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        height: 100vh;
        width: 280px;
        background: rgba(10, 14, 26, 0.98);
        flex-direction: column;
        padding: 5rem 2rem;
        gap: 1.5rem;
        transition: right 0.3s ease;
        border-left: 1px solid rgba(0, 212, 255, 0.1);
    }

    .nav-links.active {
        right: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-stats {
        gap: 2rem;
    }

    .stat-number, .stat-suffix {
        font-size: 1.8rem;
    }

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

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

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