/* ============================================
   星朗浩宇代理 Covesion 品牌门户 - 全局样式
   风格: 蓝色科技风 (参考 Covesion.com + auniontech.com)
   ============================================ */

/* --- CSS Reset & Variables --- */
:root {
    /* Covesion Brand Colors */
    --primary: #00AEEA;        /* Covesion Blue */
    --primary-light: #33C4F0;
    --primary-dark: #03242F;   /* Covesion Dark Navy */
    --accent: #F6A000;         /* Covesion Orange */
    --accent-light: #FFB833;
    --green: #00AA80;          /* Covesion Green */
    --green-light: #33CCAA;
    --red: #E73747;            /* Covesion Red */
    --red-light: #F06070;
    --text: #03242F;
    --text-light: #8A8A8A;
    --bg: #FEFEFE;
    --bg-light: #F5F7FA;
    --bg-dark: #03242F;
    --border: rgba(3, 36, 47, 0.25);
    --success: #28a745;
    --shadow: 0 2px 12px rgba(3, 36, 47, 0.08);
    --shadow-hover: 0 8px 30px rgba(3, 36, 47, 0.15);
    --radius: 20px;
    --radius-sm: 10px;
    --radius-pill: 20px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 200px;
}

body {
    font-family: "Tenon", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    font-size: 16px;
    font-weight: 300;
}

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

a:hover {
    color: var(--accent-light);
}

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

ul, ol {
    list-style: none;
}

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

/* --- Header / Navigation --- */
.header {
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 1px 4px rgba(3, 36, 47, 0.06);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 96px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-img {
    height: 48px;
}

.logo-img--brightstars {
    height: 56px;
    opacity: 0.9;
}

.logo-text {
    font-size: 14px;
    font-weight: 500;
    color: var(--primary-dark);
    white-space: nowrap;
}

.logo-sub {
    font-size: 12px;
    color: var(--text-light);
    font-weight: 400;
}

.nav {
    display: flex;
    gap: 36px;
}

.nav a {
    color: var(--text);
    font-size: 15px;
    font-weight: 500;
    padding: 8px 0;
    position: relative;
    transition: var(--transition);
}

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

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

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

/* Mobile menu toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 8px;
}

.menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text);
    transition: var(--transition);
}

/* --- About Section (公司简介 + 数据) --- */
.about-section {
    padding: 80px 0;
}

.about-intro {
    margin-bottom: 48px;
}

.about-intro h2 {
    font-size: 2rem;
    font-weight: 600;
    color: var(--primary-dark);
    margin-bottom: 16px;
}

.about-intro p {
    font-size: 1rem;
    color: var(--text-light);
    font-weight: 300;
    line-height: 1.8;
    margin-bottom: 12px;
}

.about-intro p:last-of-type {
    margin-bottom: 0;
}

/* --- About Stats (圆形环 + 数字动画) --- */
.about-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    text-align: center;
}

.about-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.about-stat-circle {
    width: 140px;
    height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 12px;
    position: relative;
}

.about-stat-circle svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    /* Rotate 90° so the arc starts at 6 o'clock (bottom) */
    transform: rotate(90deg);
}

/* 小圆点跟随旋转动画（JS 驱动 transform，CSS 仅处理 opacity） */
.about-stat-circle .circle-dot-group {
    transform-origin: 80px 80px;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.about-stat:nth-child(1) circle { stroke: var(--red); }
.about-stat:nth-child(1) .circle-dot { fill: var(--red); }
.about-stat:nth-child(2) circle { stroke: var(--primary); }
.about-stat:nth-child(2) .circle-dot { fill: var(--primary); }
.about-stat:nth-child(3) circle { stroke: var(--green); }
.about-stat:nth-child(3) .circle-dot { fill: var(--green); }
.about-stat:nth-child(4) circle { stroke: var(--accent); }
.about-stat:nth-child(4) .circle-dot { fill: var(--accent); }

.about-stat-number {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--primary-dark);
    line-height: 1;
}

.about-stat p {
    font-size: 0.85rem;
    color: var(--text-light);
    font-weight: 300;
    line-height: 1.4;
}

/* --- Stats Counter Section --- */
.stats-counter {
    padding: 60px 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    text-align: center;
}

.stat-item {
    padding: 20px;
    position: relative;
}

.stat-item:not(:last-child)::after {
    content: '';
    position: absolute;
    right: 0;
    top: 20%;
    height: 60%;
    width: 1px;
    background: var(--border);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 500;
    margin-bottom: 8px;
    line-height: 1.2;
}

.stat-item:nth-child(1) .stat-number { color: var(--primary); }
.stat-item:nth-child(2) .stat-number { color: var(--accent); }
.stat-item:nth-child(3) .stat-number { color: var(--green); }
.stat-item:nth-child(4) .stat-number { color: var(--red); }

.stat-item p {
    font-size: 0.9rem;
    color: var(--text-light);
    font-weight: 300;
}

/* --- Authorized Brand Section --- */
.authorized-brand {
    background: var(--bg);
    padding: 48px 0;
    text-align: center;
    border-bottom: 1px solid var(--border);
}

.brand-label {
    font-size: 14px;
    color: var(--text-light);
    letter-spacing: 2px;
    margin-bottom: 24px;
    text-transform: uppercase;
}

.brand-logo {
    max-width: 320px;
    height: auto;
}

/* --- Hero Carousel --- */
.hero-carousel {
    position: relative;
    overflow: hidden;
    background: #03242F;
}

.hero-carousel::before {
    content: '';
    display: block;
    padding-top: 31.1%; /* 1048 x 326 设计图宽高比 */
}

.hero-carousel-track {
    display: flex;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    width: 200%;
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
}

.hero-slide {
    width: 50%;
    flex-shrink: 0;
    position: relative;
    overflow: hidden;
}

/* Slide 1: Fixed design image with overlay buttons */
.hero-slide--fixed {
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-fixed-bg {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.hero-fixed-overlay {
    position: absolute;
    bottom: 80px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.hero-fixed-btns {
    display: flex;
    gap: 16px;
    justify-content: center;
}

/* Slide 2: Product banner image */
.hero-slide--product {
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-slide-img-full {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* Carousel dots */
.hero-carousel-dots {
    position: absolute;
    bottom: 16px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 8px;
    z-index: 10;
}

.hero-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.4);
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

.hero-dot.active {
    background: var(--accent);
    transform: scale(1.2);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 32px;
    border-radius: var(--radius-pill);
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    text-align: center;
    min-height: 41px;
}

.btn-primary {
    background: var(--accent);
    color: #FEFEFE;
}

.btn-primary:hover {
    background: var(--accent-light);
    color: #FEFEFE;
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(246, 160, 0, 0.3);
}

.btn-outline {
    background: transparent;
    color: #FEFEFE;
    border: 1px solid rgba(255, 255, 255, 0.5);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    color: #FEFEFE;
    border-color: #FEFEFE;
    transform: translateY(-2px);
}

/* --- Wavelength Conversion Animation (独立浅色区块) --- */
.wavelength-animation {
    background: var(--bg);
    padding: 20px 0 24px;
    position: relative;
    overflow: visible;
}

.wavelength-animation-inner {
    max-width: 900px;
    margin: 0 auto;
}

/* Spectrum bar */
.spectrum-bar {
    height: 6px;
    border-radius: 3px;
    background: linear-gradient(90deg,
        #4B0082 0%,    /* UV */
        #6B46C1 5%,
        #3B82F6 15%,   /* Blue */
        #06B6D4 25%,
        #10B981 35%,   /* Green */
        #F59E0B 50%,   /* Yellow/Orange */
        #EF4444 60%,   /* Red */
        #DC2626 65%,
        #7C3AED 70%,   /* IR begins */
        #6366F1 78%,
        #3B82F6 85%,
        #1E40AF 92%,
        #03242F 100%   /* Mid-IR */
    );
    margin-bottom: 40px;
    opacity: 0.85;
}

.wavelength-anim-row {
    position: relative;
    display: flex;
    align-items: center;
    height: 160px;
}

/* SVG wraps behind boxes */
.wave-svg-wrap {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 0;
}

.wave-svg {
    width: 100%;
    height: 100%;
    display: block;
}

/* Wavelength boxes sit on top, pinned to edges */
.wavelength-box {
    flex-shrink: 0;
    width: 132px;
    padding: 21px 15px;
    border-radius: 21px;
    text-align: center;
    background: var(--bg-light);
    border: 1px solid var(--border);
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1;
    transition: var(--transition);
}

.wavelength-box:hover {
    box-shadow: var(--shadow);
    transform: translateY(-50%) scale(1.04);
}

.wavelength-box--left {
    left: 0;
    border-color: rgba(124, 58, 237, 0.3);
}

.wavelength-box--right {
    right: 0;
    border-color: rgba(239, 68, 68, 0.3);
}

.wavelength-label {
    display: block;
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--primary-dark);
    line-height: 1;
}

/* Spacer between boxes (invisible, takes remaining space) */
.wavelength-gap {
    flex: 1;
}

/* Sine wave animation */
.wave-sine {
    stroke-dasharray: 20 14;
    animation: sineShift 2s linear infinite;
}

@keyframes sineShift {
    0% { stroke-dashoffset: 0; }
    100% { stroke-dashoffset: -200; }
}

/* Responsive */
@media (max-width: 768px) {
    .wavelength-anim-row {
        flex-direction: row;
        height: 100px;
    }
    .wavelength-box {
        width: 72px;
        padding: 12px 8px;
    }
    .wavelength-label {
        font-size: 1.15rem;
    }
    .spectrum-bar {
        margin-bottom: 28px;
    }
    .wavelength-animation {
        padding: 24px 0 24px;
    }
}

/* --- Section Common --- */
.section {
    padding: 80px 0;
}

.section-light {
    background: var(--bg-light);
}

.section-title {
    text-align: center;
    margin-bottom: 48px;
}

.section-title h2 {
    font-size: 2.5rem;
    font-weight: 600;
    color: var(--primary-dark);
    margin-bottom: 12px;
}

.section-title p {
    font-size: 1.1rem;
    color: var(--text-light);
    font-weight: 300;
}

/* --- Solution Cards (大卡片: 波长转换 / 电光调制) --- */
.solution-card {
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: var(--bg);
    overflow: hidden;
    transition: var(--transition);
    margin-bottom: 24px;
}

.solution-card:first-child {
    margin-top: 8px;
}

.solution-card:last-child {
    margin-bottom: 0;
}

.solution-card:hover {
    box-shadow: var(--shadow-hover);
}

.solution-card-header {
    display: block;
    padding: 14px 28px;
    color: #FEFEFE !important;
    font-size: 1.5rem;
    font-weight: 600;
    text-decoration: none;
}

.solution-card-body {
    padding: 16px 28px;
}

.solution-card-body > p {
    font-size: 0.95rem;
    color: var(--text-light);
    font-weight: 300;
    line-height: 1.7;
    margin-bottom: 12px;
}

/* Category list inside solution card */
.solution-card-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.solution-card-links li {
    border-bottom: none;
}

.solution-card-links li:last-child {
    border-bottom: none;
}

.solution-card-links a {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 0;
    color: var(--text);
    font-size: 0.95rem;
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition);
}

.solution-card-links a:hover {

    color: var(--primary);
}

.solution-card-links a::after {
    content: '→';
    font-size: 1.2rem;
    color: var(--text-light);
    transition: var(--transition);
}

.solution-card-links a:hover::after {
    color: var(--primary);
    transform: translateX(4px);
}

/* 波长转换 - 蓝色系 */
.solution-card.wavelength .solution-card-header {
    background: var(--primary);
}

/* 电光调制 - 紫色系 */
.solution-card.eom .solution-card-header {
    background: #8B5CF6;
}

/* 温控 - 绿色系 */
.solution-card.temperature .solution-card-header {
    background: var(--green);
}

/* --- Product Sections (波长转换 / 电光调制) --- */
#product-sections {
    padding: 80px 0 36px;
}

#product-sections .container {
    max-width: 960px;
}

/* --- Home Page Category Cards (4 cards for product categories) --- */
.home-category-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.home-category-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 32px 20px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: var(--bg);
    transition: var(--transition);
    text-decoration: none;
    color: var(--text);
    position: relative;
    overflow: hidden;
}

.home-category-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    z-index: 1;
}

.home-category-card:nth-child(1)::before { background: var(--primary); }
.home-category-card:nth-child(2)::before { background: var(--green); }
.home-category-card:nth-child(3)::before { background: var(--accent); }
.home-category-card:nth-child(4)::before { background: var(--red); }

.home-category-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
    color: var(--text);
    text-decoration: none;
}

.home-category-card:hover .home-category-icon {
    transform: scale(1.1);
}

.home-category-icon {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    transition: var(--transition);
}

.home-category-card:nth-child(1) .home-category-icon { background: rgba(0, 174, 234, 0.1); color: var(--primary); }
.home-category-card:nth-child(2) .home-category-icon { background: rgba(0, 170, 128, 0.1); color: var(--green); }
.home-category-card:nth-child(3) .home-category-icon { background: rgba(246, 160, 0, 0.1); color: var(--accent); }
.home-category-card:nth-child(4) .home-category-icon { background: rgba(231, 55, 71, 0.1); color: var(--red); }

.home-category-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-dark);
    margin-bottom: 8px;
}

.home-category-card p {
    font-size: 0.9rem;
    color: var(--text-light);
    font-weight: 300;
    line-height: 1.5;
}

/* --- Product Cards (Covesion Style) --- */
.product-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.product-card {
    background: var(--bg);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    overflow: hidden;
    transition: var(--transition);
    position: relative;
}

.product-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--primary);
    z-index: 1;
}

.product-card:nth-child(3n+1)::before { background: var(--primary); }
.product-card:nth-child(3n+2)::before { background: var(--green); }
.product-card:nth-child(3n)::before { background: var(--accent); }

.product-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
    background: rgba(0, 174, 234, 0.02);
}

.product-card-img {
    width: 100%;
    height: 200px;
    background: var(--bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 14px;
    border-bottom: 1px solid var(--border);
}

.product-card-body {
    padding: 24px;
}

.product-card-body h3 {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--primary-dark);
    margin-bottom: 10px;
}

.product-card-body p {
    font-size: 0.95rem;
    color: var(--text-light);
    line-height: 1.6;
    margin-bottom: 16px;
    font-weight: 300;
}

.product-card-body .link {
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--primary);
}

.product-card-body .link:hover {
    color: var(--accent);
}

/* --- Feature Blocks (Why Choose Us) --- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}

.feature-block {
    text-align: center;
    padding: 32px 20px;
}

.feature-icon {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    color: #fff;
    font-size: 20px;
    font-weight: 700;
}

.feature-block:nth-child(1) .feature-icon {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
}
.feature-block:nth-child(2) .feature-icon {
    background: linear-gradient(135deg, var(--green), var(--green-light));
}
.feature-block:nth-child(3) .feature-icon {
    background: linear-gradient(135deg, var(--accent), var(--accent-light));
}
.feature-block:nth-child(4) .feature-icon {
    background: linear-gradient(135deg, var(--red), var(--red-light));
}

.feature-block h3 {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--primary-dark);
    margin-bottom: 10px;
}

.feature-block p {
    font-size: 0.95rem;
    color: var(--text-light);
    line-height: 1.7;
    font-weight: 300;
}

/* --- Applications (4-Color Cards) --- */
.app-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.app-card {
    border-radius: var(--radius);
    padding: 32px 24px;
    color: #FEFEFE;
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.app-card:nth-child(1) { background: linear-gradient(135deg, var(--primary), var(--primary-light)); }
.app-card:nth-child(2) { background: linear-gradient(135deg, var(--green), var(--green-light)); }
.app-card:nth-child(3) { background: linear-gradient(135deg, var(--accent), var(--accent-light)); }
.app-card:nth-child(4) { background: linear-gradient(135deg, var(--red), var(--red-light)); }

.app-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.app-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.app-card p {
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 300;
}

/* --- News Cards --- */
.news-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.news-card {
    background: var(--bg);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    overflow: hidden;
    transition: var(--transition);
}

.news-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

.news-card-body {
    padding: 24px;
    border-left: 3px solid var(--primary);
}

.news-card:nth-child(2) .news-card-body { border-left-color: var(--green); }
.news-card:nth-child(3) .news-card-body { border-left-color: var(--accent); }

.news-date {
    font-size: 0.85rem;
    color: var(--primary);
    margin-bottom: 8px;
    font-weight: 500;
}

.news-card-body h3 {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text);
    margin-bottom: 8px;
    line-height: 1.5;
}

.news-card-body p {
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.6;
    font-weight: 300;
}

/* --- CTA Section --- */
.cta {
    background: linear-gradient(180deg, #03242F 0%, #17556A 100%);
    color: #FEFEFE;
    text-align: center;
    padding: 80px 0;
    position: relative;
}

.cta::before {
    content: '';
    position: absolute;
    top: -50px;
    left: 0;
    right: 0;
    height: 50px;
    background: var(--bg);
    border-bottom-left-radius: 100%;
    border-bottom-right-radius: 100%;
}

.cta h2 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 12px;
    position: relative;
    z-index: 1;
}

.cta p {
    font-size: 1.1rem;
    opacity: 0.85;
    margin-bottom: 32px;
    font-weight: 300;
    position: relative;
    z-index: 1;
}

/* --- Footer --- */
.footer {
    background: #32373C;
    color: rgba(255, 255, 255, 0.7);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand h3 {
    font-size: 1.25rem;
    color: #FEFEFE;
    margin-bottom: 16px;
}

.footer-brand .footer-logos {
    display: flex;
    align-items: center;
    justify-content: space-evenly;
    margin-top: 16px;
    margin-bottom: 16px;
    background: #ffffff;
    border: none;
    border-radius: 8px;
    padding: 12px 16px;
}

.footer-logo {
    height: 40px;
    width: auto;
    object-fit: contain;
    transition: opacity 0.3s ease;
}

.footer-logo--covesion {
    border-radius: 0;
    padding: 0;
}

.footer-logo--brightstars {
    height: 48px;
    filter: brightness(1.4) saturate(1.2);
}

.footer-logo:hover {
    opacity: 0.9;
}

.footer-brand p {
    font-size: 0.9rem;
    line-height: 1.7;
    font-weight: 300;
    margin-bottom: 0;
}

.footer h4 {
    font-size: 0.95rem;
    color: #FEFEFE;
    margin-bottom: 16px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.footer h4::after {
    content: '';
    display: block;
    width: 30px;
    height: 2px;
    margin-top: 8px;
}

.footer > .container > .footer-grid > div:nth-child(1) h4::after { background: var(--primary); }
.footer > .container > .footer-grid > div:nth-child(2) h4::after { background: var(--accent); }
.footer > .container > .footer-grid > div:nth-child(3) h4::after { background: var(--red); }
.footer > .container > .footer-grid > div:nth-child(4) h4::after { background: var(--green); }

.footer ul li {
    margin-bottom: 10px;
}

.footer ul li a {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
    transition: var(--transition);
    font-weight: 300;
}

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

.footer-contact p {
    font-size: 0.9rem;
    margin-bottom: 8px;
    line-height: 1.6;
    font-weight: 300;
}

.footer-contact a {
    color: rgba(255, 255, 255, 0.6);
}

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

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 24px;
    text-align: center;
    font-size: 0.85rem;
    font-weight: 300;
}

/* --- Page Header (Sub-pages) --- */
.page-header {
    background: linear-gradient(180deg, #03242F 0%, #17556A 100%);
    color: #FEFEFE;
    padding: 80px 0 70px;
    text-align: center;
    position: relative;
}

.page-header h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 16px;
    position: relative;
    z-index: 1;
}

.page-header p {
    font-size: 1.2rem;
    opacity: 0.85;
    font-weight: 300;
    position: relative;
    z-index: 1;
}

.about-content {
    padding: 80px 0;
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text h2 {
    font-size: 28px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 16px;
}

.about-text p {
    font-size: 15px;
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 16px;
}

.about-image {
    background: var(--bg-light);
    border-radius: var(--radius);
    height: 360px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 14px;
}

/* --- Products Page --- */
.products-section {
    padding: 48px 0 80px;
}

/* Category Quick Nav */
.product-category-nav {
    display: flex;
    justify-content: space-between;
    margin-bottom: 48px;
    padding: 12px 16px;
    background: var(--bg-light);
    border-radius: var(--radius);
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    position: sticky;
    top: 96px;
    z-index: 998;
    box-shadow: 0 2px 8px rgba(3, 36, 47, 0.06);
}

.product-category-nav::-webkit-scrollbar {
    height: 4px;
}

.product-category-nav::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 2px;
}

.cat-nav-item {
    display: inline-flex;
    align-items: center;
    padding: 10px 20px;
    border-radius: var(--radius-pill);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text);
    text-decoration: none;
    white-space: nowrap;
    background: var(--bg);
    border: 1px solid var(--border);
    transition: var(--transition);
}

.cat-nav-item:hover {
    color: var(--primary);
    border-color: var(--primary);
    background: rgba(0, 174, 234, 0.05);
}

.cat-nav-item.active {
    color: #fff;
    background: var(--primary);
    border-color: var(--primary);
}

/* Category Section */
.product-category {
    margin-bottom: 64px;
}

.product-category:last-child {
    margin-bottom: 0;
}

.category-header {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 32px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--border);
    flex-wrap: wrap;
}

.category-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    font-size: 18px;
    font-weight: 600;
    flex-shrink: 0;
}

.category-header h2 {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--primary-dark);
    margin: 0;
}

.category-header p {
    font-size: 1rem;
    color: var(--text-light);
    font-weight: 300;
    margin: 0 0 0 12px;
}

/* Category Product Grid (smaller cards) */
.category-product-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

/* Mini Product Card */
.mini-product-card {
    background: var(--bg);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    overflow: hidden;
    transition: var(--transition);
    position: relative;
    display: flex;
    flex-direction: column;
}

.mini-product-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary);
    z-index: 1;
}

.mini-product-card:nth-child(4n+1)::before { background: var(--primary); }
.mini-product-card:nth-child(4n+2)::before { background: var(--green); }
.mini-product-card:nth-child(4n+3)::before { background: var(--accent); }
.mini-product-card:nth-child(4n)::before { background: var(--red); }

.mini-product-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
    background: rgba(0, 174, 234, 0.02);
}

.mini-product-img {
    width: 100%;
    height: 160px;
    background: var(--bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 14px;
    border-bottom: 1px solid var(--border);
}

.mini-product-body {
    padding: 16px;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.mini-product-body p {
    flex: 1;
}

.mini-product-body h3 {
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--primary-dark);
    margin-bottom: 8px;
}

.mini-product-body p {
    font-size: 0.85rem;
    color: var(--text-light);
    line-height: 1.6;
    margin-bottom: 12px;
    font-weight: 300;
}

.mini-product-body .link {
    font-size: 0.8rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--primary);
}

.mini-product-body .link:hover {
    color: var(--accent);
}

/* Empty category state */
.product-category .category-header + p {
    font-size: 0.95rem;
    color: var(--text-light);
    font-style: italic;
    padding: 20px 0;
}

/* --- Knowledge Center --- */
.video-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.video-card {
    display: block;
    background: var(--bg);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    overflow: hidden;
    transition: var(--transition);
    text-decoration: none;
    color: var(--text);
}

.video-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
    color: var(--text);
    text-decoration: none;
}

.video-thumbnail {
    width: 100%;
    height: 180px;
    background: linear-gradient(135deg, var(--primary-dark), #17556A);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    transition: var(--transition);
}

.video-card:hover .video-thumbnail {
    filter: brightness(1.1);
}

.video-play-btn {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.video-card:hover .video-play-btn {
    transform: scale(1.1);
}

/* B站嵌入 iframe */
.video-embed {
    border: none;
    border-radius: 0;
    overflow: hidden;
}

.video-card-body {
    padding: 20px;
}

.video-card-body h3 {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--primary-dark);
    margin-bottom: 8px;
    line-height: 1.4;
}

.video-card-body p {
    font-size: 0.85rem;
    color: var(--text-light);
    line-height: 1.6;
    font-weight: 300;
}

/* Article List */
.article-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
    max-width: 900px;
    margin: 0 auto;
}

.article-card {
    display: block;
    background: var(--bg);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    padding: 24px;
    transition: var(--transition);
    text-decoration: none;
    color: var(--text);
    position: relative;
    overflow: hidden;
}

.article-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 100%;
    background: var(--primary);
    transform: scaleY(0);
    transition: transform 0.3s ease;
}

.article-card:hover::before {
    transform: scaleY(1);
}

.article-card:hover {
    box-shadow: var(--shadow-hover);
    color: var(--text);
    text-decoration: none;
}

.article-tag {
    display: inline-block;
    padding: 4px 12px;
    border-radius: var(--radius-pill);
    font-size: 0.75rem;
    font-weight: 500;
    margin-bottom: 10px;
}

.article-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-dark);
    margin-bottom: 8px;
    line-height: 1.4;
}

.article-card p {
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.7;
    font-weight: 300;
}

/* --- Contact Page --- */
.contact-section {
    padding: 60px 0 80px;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    max-width: 1100px;
    margin: 0 auto;
}

.contact-info h2 {
    font-size: 24px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 16px;
}

.contact-info p {
    font-size: 15px;
    color: var(--text-light);
    line-height: 1.7;
    margin-bottom: 24px;
}

.contact-item {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
    align-items: flex-start;
}

.contact-item-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--accent);
    font-size: 16px;
}

.contact-item-text h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 4px;
}

.contact-item-text p {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 0;
}

.contact-form {
    background: var(--bg-light);
    border-radius: var(--radius);
    padding: 32px;
}

.contact-form h2 {
    font-size: 20px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 24px;
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: var(--text);
    margin-bottom: 6px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    font-family: inherit;
    transition: var(--transition);
    background: var(--bg);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

.form-group textarea {
    height: 120px;
    resize: vertical;
}

/* --- Map Placeholder --- */
.map-placeholder {
    margin-top: 48px;
    height: 300px;
    background: var(--bg-light);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 15px;
    border: 1px dashed var(--border);
}

/* --- Back to Top Button --- */
.back-to-top {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    box-shadow: 0 4px 12px rgba(0, 174, 234, 0.3);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0, 174, 234, 0.4);
}

/* --- Header scroll effect --- */
.header.scrolled {
    box-shadow: 0 2px 20px rgba(3, 36, 47, 0.12);
}

/* Mobile menu animation - only within mobile breakpoint */

/* Staggered animation for scroll items */
.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Pulse animation for CTA buttons */
@keyframes pulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(246, 160, 0, 0.4); }
    50% { box-shadow: 0 0 0 12px rgba(246, 160, 0, 0); }
}

.btn-pulse {
    animation: pulse 2s infinite;
}

/* Form success message */
.form-success {
    background: #d4edda;
    border: 1px solid #c3e6cb;
    border-radius: var(--radius-sm);
    padding: 16px;
    margin-top: 16px;
    color: #155724;
    font-size: 14px;
    display: none;
    animation: slideDown 0.3s ease;
}

.form-success.show {
    display: block;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* --- Responsive --- */
@media (max-width: 1024px) {
    .product-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .home-category-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .category-product-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .app-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .hero h1 {
        font-size: 3rem;
    }
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .about-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    .stat-item:not(:last-child)::after {
        display: none;
    }
    .video-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }
    .nav {
        display: none;
        position: absolute;
        top: 80px;
        left: 0;
        right: 0;
        background: var(--bg);
        flex-direction: column;
        padding: 20px;
        gap: 0;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow);
    }
    .nav {
        transform: translateY(-10px);
        opacity: 0;
        transition: transform 0.3s ease, opacity 0.3s ease;
    }
    .nav.open {
        display: flex;
        transform: translateY(0);
        opacity: 1;
    }
    .nav a {
        padding: 12px 0;
        border-bottom: 1px solid var(--border);
    }
    .nav a::after {
        display: none;
    }
    .hero-slide:first-child {
        padding: 40px 0 40px;
    }
    .hero h1 {
        font-size: 2rem;
    }
    .hero p {
        font-size: 1rem;
    }
    .hero-btns {
        flex-direction: column;
        align-items: center;
    }
    .product-grid,
    .news-grid,
    .home-category-grid {
        grid-template-columns: 1fr;
    }
    .about-stats {
        grid-template-columns: 1fr;
    }
    .features-grid,
    .about-grid,
    .contact-grid {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr;
    }
    .section {
        padding: 60px 0;
    }
    .section-title h2 {
        font-size: 1.75rem;
    }
    .page-header h1 {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .features-grid,
    .app-grid {
        grid-template-columns: 1fr;
    }
    .hero-slide:first-child {
        padding: 36px 0 36px;
    }
    .hero h1 {
        font-size: 1.75rem;
    }
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 40px;
        height: 40px;
    }
}