/* ===================================
   柏升工業 (Cypress) - Corporate Style
   Brand Colors: Green #2E7D32 + Navy #1A2C5C
   =================================== */

/* CSS Variables */
:root {
    /* Brand Colors — 取自 Logo 實際像素 */
    --brand-green: #8EBD25;          /* Logo 黃綠 — 活力/自然 */
    --brand-green-hover: #76A01A;    /* 加深10% */
    --brand-green-light: #F2F8E0;    /* 極淡黃綠，hover 背景 */
    --brand-green-mid: #A3CE3F;      /* 偏亮版，icon 漸層 */
    --brand-teal: #27A0C9;           /* Logo 青藍 — 精準/科技 */
    --brand-teal-hover: #1B85A8;     /* 加深版 */
    --brand-teal-dark: #1A6B8E;      /* 深版 — Footer/heading */
    --brand-teal-light: #E6F6FB;     /* 極淡青藍，tint 用 */
    /* 保留 navy 別名指向深青藍，維持舊引用相容 */
    --brand-navy: #1A6B8E;
    --brand-navy-hover: #145A78;
    --brand-navy-light: #E6F6FB;

    /* Legacy / Neutral */
    --primary-color: #333333;
    --secondary-color: #666666;
    --accent-color: var(--brand-navy);
    --bg-white: #ffffff;
    --bg-light: #fafafa;
    --bg-gray: #f5f5f5;
    --border-color: #e0e0e0;
    --text-dark: #2b2b2b;
    --text-light: #555555;
    --text-muted: #999999;

    /* Shadows */
    --shadow: 0 4px 24px rgba(39, 160, 201, 0.08);
    --shadow-hover: 0 8px 32px rgba(39, 160, 201, 0.16);
    --shadow-green: 0 4px 20px rgba(142, 189, 37, 0.25);
    --shadow-teal: 0 4px 20px rgba(39, 160, 201, 0.28);

    /* Transitions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.18s ease;

    --container-width: 1400px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans TC',
                 'PingFang TC', 'Microsoft JhengHei', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

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

ul { list-style: none; }

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

/* Container */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 32px;
    font-size: 21px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    border: 2px solid transparent;
    border-radius: 4px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

/* Shine effect on hover */
.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 60%;
    height: 100%;
    background: linear-gradient(120deg, transparent, rgba(255,255,255,0.18), transparent);
    transition: left 0.45s ease;
}
.btn:hover::before { left: 140%; }

.btn-primary {
    background-color: var(--brand-teal);
    color: #fff;
    border-color: var(--brand-teal);
    box-shadow: 0 2px 8px rgba(39, 160, 201, 0.28);
}
.btn-primary:hover {
    background-color: var(--brand-teal-hover);
    border-color: var(--brand-teal-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-teal);
}
.btn-primary:active {
    transform: translateY(0);
    box-shadow: none;
}

.btn-outline {
    background-color: transparent;
    color: var(--brand-teal-dark);
    border-color: var(--brand-teal);
}
.btn-outline:hover {
    background-color: var(--brand-teal);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: var(--shadow-teal);
}

.btn-green-outline {
    background-color: transparent;
    color: var(--brand-green);
    border-color: var(--brand-green);
}
.btn-green-outline:hover {
    background-color: var(--brand-green);
    color: #fff;
    transform: translateY(-2px);
}

/* ===================================
   Header
   =================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--bg-white);
    box-shadow: 0 2px 16px rgba(26, 44, 92, 0.08);
    z-index: 1000;
    transition: box-shadow 0.3s ease;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 120px;
    max-width: 100%;
    padding: 0 30px;
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.logo img {
    height: 54px;
    width: auto;
    max-width: 390px;
    object-fit: contain;
    display: block;
    image-rendering: -webkit-optimize-contrast;
    transition: opacity 0.2s ease;
}
.logo img:hover { opacity: 0.85; }

.logo-text {
    font-size: 33px;
    font-weight: 700;
    color: var(--brand-navy);
    letter-spacing: 1px;
}

/* Navigation */
.nav-list {
    display: flex;
    gap: 0;
    align-items: center;
}

.nav-link {
    display: block;
    font-size: 20px;
    font-weight: 500;
    letter-spacing: 0.2px;
    color: #555;
    position: relative;
    padding: 8px 9px;
    transition: color 0.18s ease;
    white-space: nowrap;
}

.nav-link::after { display: none; }

.nav-link:hover {
    color: var(--brand-teal);
    background: transparent;
}
.nav-link.active {
    color: var(--brand-teal-dark);
    font-weight: 600;
    background: transparent;
    box-shadow: none;
}

/* Nav right-align — 無容器 */
.nav {
    margin-left: auto;
    background: transparent;
    border-radius: 0;
    padding: 0;
    border: none;
}

/* Dropdown */
.nav-dropdown { position: relative; }

/* CSS chevron arrow (replaces ▾ text) */
.nav-has-dropdown {
    padding-right: 28px;
}
.nav-has-dropdown::before {
    content: '';
    position: absolute;
    right: 10px;
    top: 50%;
    width: 5px;
    height: 5px;
    border-right: 1.5px solid currentColor;
    border-bottom: 1.5px solid currentColor;
    transform: translateY(-65%) rotate(45deg);
    transition: transform 0.2s ease;
    pointer-events: none;
}
.nav-dropdown:hover .nav-has-dropdown::before {
    transform: translateY(-35%) rotate(-135deg);
}

.nav-dropdown-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(4px);
    background: white;
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.13), 0 2px 8px rgba(0,0,0,0.06);
    padding: 6px;
    padding-top: 14px; /* 8px 視覺間距 + 6px 原始 padding，橋接 hover 區域 */
    min-width: 130px;
    z-index: 1001;
    border: 1px solid rgba(0,0,0,0.06);
    white-space: nowrap;
    /* Fade + slide animation */
    visibility: hidden;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
}
.nav-dropdown:hover .nav-dropdown-menu {
    visibility: visible;
    opacity: 1;
    transform: translateX(-50%) translateY(0);
    pointer-events: auto;
}

.nav-dropdown-item {
    display: block;
    padding: 8px 16px;
    font-size: 20px;
    color: var(--text-dark);
    border-radius: 8px;
    transition: background 0.15s, color 0.15s;
}
.nav-dropdown-item:hover {
    color: var(--brand-teal);
    background: var(--brand-teal-light);
}

/* Mobile toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}
.nav-toggle span {
    display: block;
    width: 25px;
    height: 2px;
    background-color: var(--text-dark);
    transition: var(--transition);
    border-radius: 2px;
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    position: relative;
    height: 70vh;
    min-height: 600px;
    background-color: var(--bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 120px;
}

.hero-slider {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.hero-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 1.2s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}
.hero-slide.active { opacity: 1; }

.hero-slide-bg {
    position: absolute;
    inset: 0;
    background-color: #ffffff;
    background-repeat: no-repeat;
    background-size: contain;
    background-position: center center;
    transform: scale(1.08);
    will-change: transform;
    z-index: 0;
}
.hero-slide.active .hero-slide-bg {
    animation: kenBurns 7s cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards;
}
@keyframes kenBurns {
    from { transform: scale(1.08); }
    to   { transform: scale(1.0); }
}

.hero-slide-overlay {
    display: none;
    position: absolute;
    inset: 0;
    background: linear-gradient(
        135deg,
        rgba(0, 20, 50, 0.60) 0%,
        rgba(0, 20, 50, 0.10) 50%,
        rgba(0, 20, 50, 0.50) 100%
    );
    z-index: 1;
}
.hero-slide.has-image .hero-slide-overlay { display: block; }
.hero-slide.has-image .hero-content h1 { color: #ffffff; }
.hero-slide.has-image .hero-content p { color: rgba(255, 255, 255, 0.88); }

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 40px;
    max-width: 800px;
}
.hero-content h1 {
    font-size: 72px;
    font-weight: 300;
    color: var(--brand-navy);
    margin-bottom: 20px;
    letter-spacing: 2px;
    line-height: 1.3;
    opacity: 0;
    transform: translateY(28px);
}
.hero-content p {
    font-size: 27px;
    color: var(--text-light);
    margin-bottom: 30px;
    opacity: 0;
    transform: translateY(28px);
}
.hero-content .btn-primary {
    opacity: 0;
    transform: translateY(28px);
}
.hero-slide.active .hero-content h1 {
    animation: heroTextIn 0.95s cubic-bezier(0.22, 1, 0.36, 1) 0.40s forwards;
}
.hero-slide.active .hero-content p {
    animation: heroTextIn 0.95s cubic-bezier(0.22, 1, 0.36, 1) 0.65s forwards;
}
.hero-slide.active .hero-content .btn-primary {
    animation: heroTextIn 0.95s cubic-bezier(0.22, 1, 0.36, 1) 0.85s forwards;
}
@keyframes heroTextIn {
    from { opacity: 0; transform: translateY(28px); }
    to   { opacity: 1; transform: translateY(0); }
}

.hero-dots {
    position: absolute;
    bottom: 36px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 8px;
    z-index: 10;
}
.dot {
    width: 36px;
    height: 3px;
    border-radius: 2px;
    background-color: rgba(255, 255, 255, 0.35);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}
.dot::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 0%;
    background-color: #ffffff;
    border-radius: 2px;
}
.dot.active::after {
    animation: dotProgress 5s linear forwards;
}
@keyframes dotProgress {
    from { width: 0%; }
    to   { width: 100%; }
}

/* ===================================
   Section Styles
   =================================== */
section { padding: 120px 0; }

.section-header {
    text-align: center;
    margin-bottom: 80px;
}
.section-header h2 {
    font-size: 54px;
    font-weight: 300;
    color: var(--brand-navy);
    letter-spacing: 2px;
    margin-bottom: 15px;
    position: relative;
    display: inline-block;
}
/* Brand accent underline — 綠+青藍漸層 */
.section-header h2::after {
    content: '';
    display: block;
    width: 48px;
    height: 3px;
    background: linear-gradient(90deg, var(--brand-green), var(--brand-teal));
    margin: 14px auto 0;
    border-radius: 2px;
    transition: width 0.3s ease;
}
.section-header:hover h2::after { width: 80px; }

.section-header p {
    font-size: 24px;
    color: var(--text-muted);
    margin-top: 8px;
}

/* ===================================
   About Section (Homepage)
   =================================== */
.about { background-color: #ffffff; }

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}
.about-text h3 {
    font-size: 36px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 20px;
}
.about-text p {
    font-size: 24px;
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.8;
}
.about-image-placeholder {
    width: 100%;
    height: 400px;
    background: linear-gradient(135deg, var(--brand-navy-light) 0%, var(--bg-gray) 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    border-radius: 8px;
}
.about-image-placeholder i {
    font-size: 120px;
    margin-bottom: 20px;
    color: var(--brand-navy);
    opacity: 0.3;
}

/* ===================================
   Products Section (Homepage)
   =================================== */
.products { background-color: #EEF2F7; }

.product-grid {
    display: flex;
    gap: 24px;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 16px;
    scrollbar-width: thin;
    scrollbar-color: #27A0C9 #EEF2F7;
}
.product-grid::-webkit-scrollbar { height: 5px; }
.product-grid::-webkit-scrollbar-track { background: #EEF2F7; }
.product-grid::-webkit-scrollbar-thumb { background: #27A0C9; border-radius: 3px; }

.product-card {
    background-color: var(--bg-white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    display: block;
    border-top: 3px solid transparent;
    flex: 0 0 calc(20% - 20px);
    min-width: 200px;
    scroll-snap-align: start;
}
.product-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-teal);
    border-top-color: var(--brand-teal);
}
.product-image {
    height: 200px;
    background-color: var(--bg-gray);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}
.product-image img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    object-position: center;
    padding: 12px;
    transition: transform 0.4s ease;
    background: #fff;
}
.product-card:hover .product-image img { transform: scale(1.06); }
.product-image i {
    font-size: 90px;
    color: var(--text-muted);
}
.product-card h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--brand-navy);
    padding: 20px 20px 10px;
}
.product-card p {
    font-size: 18px;
    color: var(--text-light);
    padding: 0 20px 20px;
}
.products-cta {
    text-align: center;
    margin-top: 50px;
}

/* ===================================
   Features Section
   =================================== */
.features {
    background-color: #ffffff;
    padding: 80px 0;
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
}
.feature-item {
    text-align: center;
    padding: 30px 20px;
    border-radius: 8px;
    transition: var(--transition);
}
.feature-item:hover {
    background-color: var(--brand-teal-light);
    transform: translateY(-4px);
}
.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--brand-teal-light), #B8E6F5);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}
.feature-item:hover .feature-icon {
    background: linear-gradient(135deg, var(--brand-teal), var(--brand-green));
}
.feature-icon i {
    font-size: 48px;
    color: var(--brand-teal);
    transition: color 0.3s ease;
}
.feature-item:hover .feature-icon i { color: #fff; }
.feature-item h3 {
    font-size: 24px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 8px;
}
.feature-item p {
    font-size: 21px;
    color: var(--text-light);
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: linear-gradient(135deg, var(--brand-teal-dark) 0%, #155070 100%);
    color: var(--bg-white);
    padding: 32px 0 16px;
}
.footer-content {
    display: block;
    margin-bottom: 20px;
}
.footer-links {
    display: none;
}
.footer-info h4 {
    font-size: 27px;
    font-weight: 600;
    margin-bottom: 14px;
    color: #fff;
}
.footer-contact {
    display: flex;
    flex-wrap: wrap;
    gap: 6px 32px;
}
.footer-contact li {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 0;
    font-size: 21px;
    color: rgba(255,255,255,0.75);
}
.footer-contact i {
    width: 20px;
    color: var(--brand-green);
}
.footer-contact a { color: rgba(255,255,255,0.75); }
.footer-contact a:hover { color: #fff; }

.footer-links h4 {
    font-size: 27px;
    font-weight: 600;
    margin-bottom: 20px;
    color: #fff;
}
.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.footer-links a {
    font-size: 21px;
    color: rgba(255,255,255,0.65);
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.footer-links a::before {
    content: '›';
    color: var(--brand-green);
    font-size: 24px;
    line-height: 1;
}
.footer-links a:hover { color: #fff; padding-left: 4px; }

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
}
.footer-bottom p {
    font-size: 20px;
    color: rgba(255,255,255,0.4);
}

/* ===================================
   Page Header (Sub-pages)
   =================================== */
.page-header {
    background: linear-gradient(135deg, var(--brand-navy-light) 0%, var(--bg-light) 60%);
    padding: 150px 0 80px;
    text-align: center;
    margin-top: 120px;
    position: relative;
    overflow: hidden;
}
.page-header::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--brand-green), transparent);
}
.page-header h1 {
    font-size: 63px;
    font-weight: 300;
    color: var(--brand-navy);
    letter-spacing: 4px;
    margin-bottom: 15px;
}
.page-header p {
    font-size: 24px;
    color: var(--text-muted);
    letter-spacing: 1px;
}

/* Page Header — 背景圖模式 */
.page-header.has-bg-image {
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}
.page-header.has-bg-image::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(5, 20, 50, 0.10);
    pointer-events: none;
}
.page-header.has-bg-image .container { position: relative; z-index: 1; }
.page-header.has-bg-image h1 { color: #fff; }
.page-header.has-bg-image p  { color: rgba(255,255,255,0.80); }
.page-header.has-bg-image::before {
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.4), transparent);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 1024px) {
    .product-grid { gap: 16px; }
    .product-card { flex: 0 0 80vw; min-width: 240px; }
    .features-grid { grid-template-columns: repeat(2, 1fr); gap: 30px; }
}

@media (max-width: 768px) {
    .nav-list {
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        background-color: var(--bg-white);
        flex-direction: column;
        align-items: center;
        padding: 30px 20px;
        gap: 8px;
        box-shadow: var(--shadow);
        transform: translateY(-150%);
        transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
        border-bottom: 3px solid var(--brand-green);
    }
    .nav-list.active { transform: translateY(0); }
    .nav-toggle { display: flex; }
    .nav-dropdown-menu {
        visibility: visible;
        opacity: 1;
        pointer-events: auto;
        position: static;
        transform: none;
        box-shadow: none;
        border: none;
        background: transparent;
        padding: 0;
        min-width: 0;
        border-radius: 0;
    }
    .nav-dropdown-item {
        padding: 6px 20px;
        font-size: 20px;
        color: var(--text-muted);
        border-radius: 0;
    }
    /* 手機版隱藏 chevron */
    .nav-has-dropdown::before { display: none; }
    .nav-has-dropdown { padding-right: 13px; }
    .hero-content h1 { font-size: 48px; }
    .about-content { grid-template-columns: 1fr; }
    .about-image-placeholder { height: 300px; }
    .footer-content { display: block; }
}

/* ===================================
   About Page
   =================================== */
.about-section {
    background-color: var(--bg-white);
    padding: 80px 0;
}
.about-main {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 60px;
    margin-bottom: 80px;
}
.about-story h2 {
    font-size: 42px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 25px;
}
.about-story p {
    font-size: 24px;
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 20px;
}
.about-stats {
    display: flex;
    flex-direction: column;
    gap: 30px;
    justify-content: center;
}
.stat-item {
    text-align: center;
    padding: 30px;
    background: linear-gradient(135deg, var(--brand-navy-light), #fff);
    border-radius: 8px;
    border-left: 4px solid var(--brand-green);
    transition: var(--transition);
}
.stat-item:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow);
}
.stat-number {
    display: block;
    font-size: 54px;
    font-weight: 700;
    color: var(--brand-green);
    margin-bottom: 10px;
}
.stat-label {
    font-size: 21px;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 1px;
}
.about-features h2 {
    font-size: 42px;
    font-weight: 600;
    color: var(--brand-navy);
    text-align: center;
    margin-bottom: 50px;
}
.feature-card {
    text-align: center;
    padding: 40px 20px;
    background-color: var(--bg-light);
    border-radius: 8px;
    transition: var(--transition);
    border-bottom: 3px solid transparent;
}
.feature-card:hover {
    background-color: var(--bg-white);
    box-shadow: var(--shadow);
    border-bottom-color: var(--brand-green);
    transform: translateY(-4px);
}
.feature-card img {
    width: 90px;
    height: 90px;
    object-fit: contain;
    margin-bottom: 20px;
}
.feature-card i {
    font-size: 72px;
    color: var(--brand-green);
    margin-bottom: 20px;
}
.feature-card h3 {
    font-size: 27px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 15px;
}
.feature-card p {
    font-size: 21px;
    color: var(--text-light);
}

/* Timeline */
.about-history h2 {
    font-size: 42px;
    font-weight: 600;
    color: var(--brand-navy);
    text-align: center;
    margin-bottom: 50px;
}
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 2px;
    height: 100%;
    background: linear-gradient(to bottom, var(--brand-green), var(--brand-navy));
}
.timeline-item {
    display: flex;
    justify-content: flex-end;
    padding-right: calc(50% + 30px);
    position: relative;
    margin-bottom: 40px;
}
.timeline-item:nth-child(even) {
    justify-content: flex-start;
    padding-right: 0;
    padding-left: calc(50% + 30px);
}
.timeline-year {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(90deg, var(--brand-teal), var(--brand-green));
    color: #fff;
    padding: 8px 20px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 21px;
    box-shadow: var(--shadow-teal);
}
.timeline-content {
    background-color: var(--bg-light);
    padding: 20px;
    border-radius: 8px;
    max-width: 300px;
    border-left: 3px solid var(--brand-green);
}
.timeline-content h3 {
    font-size: 27px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 10px;
}
.timeline-content p {
    font-size: 21px;
    color: var(--text-light);
}

/* ===================================
   Products Page
   =================================== */
.products-section {
    background-color: var(--bg-white);
    padding: 80px 0;
}
.products-filter {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
    flex-wrap: wrap;
}
.products-filter + .products-filter {
    margin-bottom: 28px;
    padding-top: 10px;
    border-top: 1px solid var(--border-color);
}
.filter-btn {
    display: inline-block;
    padding: 8px 20px;
    border: 1.5px solid var(--border-color);
    background: var(--bg-white);
    color: var(--text-dark);
    font-size: 21px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border-radius: 25px;
    text-decoration: none;
    white-space: nowrap;
}
.filter-btn:hover,
.filter-btn.active {
    background: var(--brand-teal);
    border-color: var(--brand-teal);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: var(--shadow-teal);
}
/* 子分類 active 使用綠色 */
.filter-btn.sub-active {
    background: var(--brand-green);
    border-color: var(--brand-green);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: var(--shadow-green);
}
.products-main {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 40px;
}
.products-sidebar {
    position: sticky;
    top: 120px;
    height: fit-content;
}
.products-sidebar h3 {
    font-size: 27px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--brand-green);
}
.category-list li { margin-bottom: 6px; }
.category-link {
    display: block;
    padding: 10px 15px;
    color: var(--text-dark);
    font-size: 21px;
    border-radius: 4px;
    transition: var(--transition);
    border-left: 3px solid transparent;
}
.category-link:hover,
.category-link.active {
    background-color: var(--brand-teal-light);
    color: var(--brand-teal-dark);
    font-weight: 600;
    border-left-color: var(--brand-teal);
    padding-left: 18px;
}
.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}
.product-item {
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    transition: var(--transition);
}
.product-item:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
    border-color: var(--brand-green);
}
.product-item a { display: block; }
.product-img {
    height: 240px;
    background-color: var(--bg-gray);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}
.product-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}
.product-item:hover .product-img img { transform: scale(1.06); }
.product-img i { font-size: 75px; color: var(--text-muted); }
.product-info { padding: 20px; }
.product-info h3 {
    font-size: 24px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 10px;
    line-height: 1.4;
}
.product-info p {
    font-size: 21px;
    color: var(--text-light);
}
.no-products {
    grid-column: 1 / -1;
    text-align: center;
    padding: 60px;
    color: var(--text-muted);
}
.no-products i { font-size: 72px; margin-bottom: 16px; display: block; }

/* ===================================
   Product Detail Page
   =================================== */
.product-detail-section { padding: 80px 0; position: relative; overflow: clip; }
.product-detail-section .container { max-width: 1600px; }
.product-detail-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 100px;
    align-items: start;
}
.product-detail-image {
    position: sticky;
    top: 140px;
    align-self: start;
}
.product-image-inner {
    position: relative;
}
.product-main-img {
    background-color: #fff;
    border-radius: 8px;
    height: 520px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}
.product-main-img img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}
.product-main-img i { font-size: 180px; color: var(--text-muted); }
.product-thumb-strip {
    display: flex;
    gap: 10px;
    margin-top: 12px;
    flex-wrap: wrap;
}
.product-thumb {
    width: 100px;
    height: 100px;
    border-radius: 6px;
    border: 2px solid var(--border-color);
    overflow: hidden;
    cursor: pointer;
    transition: var(--transition);
    background: #fff;
    flex-shrink: 0;
}
.product-thumb:hover,
.product-thumb.active {
    border-color: var(--brand-teal);
    box-shadow: 0 0 0 2px rgba(39, 160, 201, 0.2);
}
.product-thumb img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}
.product-detail-info h1 {
    font-size: 42px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 20px;
}
.product-detail-info .model {
    font-size: 21px;
    color: var(--text-muted);
    margin-bottom: 20px;
}
.product-detail-info .short-description {
    font-size: 22px;
    color: var(--text-light);
    line-height: 1.7;
    margin-bottom: 20px;
    padding: 12px 16px;
    background: var(--brand-green-light);
    border-left: 3px solid var(--brand-green);
    border-radius: 0 4px 4px 0;
}
.product-detail-info .description {
    font-size: 24px;
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 30px;
}
.product-specs { margin-top: 40px; }
.product-specs h3 {
    font-size: 27px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--brand-green);
}
.spec-table { width: 100%; border-collapse: collapse; }
.spec-table tr { border-bottom: 1px solid var(--border-color); }
.spec-table tr:hover { background-color: var(--brand-green-light); }
.spec-table td { padding: 12px 0; font-size: 21px; }
.spec-table td:first-child {
    font-weight: 600;
    color: var(--brand-navy);
    width: 40%;
}
.spec-table td:last-child { color: var(--text-light); }
.product-actions {
    margin-top: 40px;
    display: flex;
    gap: 15px;
}
.product-actions .btn { flex: 1; text-align: center; }
.product-breadcrumb {
    margin-bottom: 30px;
    font-size: 21px;
    color: var(--text-muted);
}
.product-breadcrumb a { color: var(--brand-green); }
.product-breadcrumb a:hover { text-decoration: underline; }

/* ===================================
   Contact Page
   =================================== */
.contact-section { padding: 50px 0; }
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}
.contact-info h2 {
    font-size: 42px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 16px;
}
.contact-info-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 14px;
    padding: 10px;
    border-radius: 8px;
    transition: var(--transition);
}
.contact-info-item:hover {
    background-color: var(--brand-green-light);
    transform: translateX(4px);
}
.contact-info-item i {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--brand-green-light), #c8e6c9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 30px;
    color: var(--brand-green);
    flex-shrink: 0;
    transition: var(--transition);
}
.contact-info-item:hover i {
    background: linear-gradient(135deg, var(--brand-green), var(--brand-green-mid));
    color: #fff;
}
.contact-info-item h4 {
    font-size: 22px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 5px;
}
.contact-info-item p { font-size: 21px; color: var(--text-light); }
.contact-info-item a { color: var(--text-light); }
.contact-info-item a:hover { color: var(--brand-green); }

.contact-map {
    margin-top: 20px;
    height: 300px;
    background-color: var(--bg-gray);
    border-radius: 8px;
    overflow: hidden;
}
.contact-map i { font-size: 90px; color: var(--text-muted); }

.contact-form h2 {
    font-size: 42px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 16px;
}
.form-group { margin-bottom: 20px; }
.form-group label {
    display: block;
    font-size: 21px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 8px;
}
.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 16px;
    border: 1.5px solid var(--border-color);
    border-radius: 4px;
    font-size: 21px;
    font-family: inherit;
    transition: var(--transition);
    color: var(--text-dark);
    background: var(--bg-white);
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--brand-green);
    box-shadow: 0 0 0 3px rgba(46, 125, 50, 0.12);
}
.form-group textarea { min-height: 150px; resize: vertical; }
.form-submit { text-align: right; }

.form-message {
    margin-top: 15px;
    padding: 12px 20px;
    border-radius: 4px;
    font-size: 21px;
}
.form-message.success {
    background-color: var(--brand-teal-light);
    color: var(--brand-teal-dark);
    border: 1px solid #b3dcee;
}
.form-message.error {
    background-color: #fdecea;
    color: #b71c1c;
    border: 1px solid #ffcdd2;
}

/* ===================================
   Downloads Page
   =================================== */
.download-filters {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}
.downloads-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}
.download-card {
    background: var(--bg-white);
    border: 1.5px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    transition: var(--transition);
}
.download-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-3px);
    border-color: var(--brand-green);
}
.download-title {
    font-size: 24px;
    font-weight: 600;
    color: var(--brand-navy);
    line-height: 1.4;
    margin: 0;
}
.download-body {
    display: flex;
    align-items: center;
    gap: 15px;
}
.download-icon {
    width: 50px;
    height: 50px;
    background: var(--brand-teal-light);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    color: var(--brand-teal);
    flex-shrink: 0;
    transition: var(--transition);
}
.download-card:hover .download-icon {
    background: linear-gradient(135deg, var(--brand-teal), var(--brand-green));
    color: #fff;
}
.download-info { flex: 1; min-width: 0; }
.download-info p {
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: 4px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.download-meta { display: flex; align-items: center; gap: 6px; font-size: 13px; color: var(--text-muted); white-space: nowrap; }
.download-meta .file-type {
    background: var(--bg-gray);
    padding: 2px 8px;
    border-radius: 4px;
    margin-right: 0;
}
.download-btn {
    padding: 10px 20px;
    background: var(--brand-green);
    color: #fff;
    border-radius: 6px;
    font-size: 21px;
    font-weight: 500;
    white-space: nowrap;
    transition: var(--transition);
}
.download-btn:hover {
    background: var(--brand-green-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-green);
}

/* ===================================
   Certifications Page
   =================================== */
/* ---- Certification Showcase (Version B) ---- */
.cert-showcase-section { padding: 80px 0; }

.cert-showcase-row {
    display: grid;
    grid-template-columns: 55fr 45fr;
    gap: 80px;
    align-items: center;
    padding: 70px 0;
    border-bottom: 1px solid var(--border-color);
}
.cert-showcase-row:first-child { padding-top: 0; }
.cert-showcase-row:last-child { border-bottom: none; padding-bottom: 0; }
.cert-showcase-row.reverse .cert-showcase-visual { order: 2; }
.cert-showcase-row.reverse .cert-showcase-info  { order: 1; }

/* Carousel */
.cert-carousel { position: relative; }
.cert-slides { position: relative; }
.cert-slide { display: none; }
.cert-slide.active { display: block; }
.cert-slide img {
    width: 100%;
    height: auto;
    max-height: 640px;
    object-fit: contain;
    display: block;
    border-radius: 10px;
    box-shadow: 0 6px 32px rgba(0,0,0,0.12);
    background: var(--bg-light);
}
.cert-placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 400px;
    background: var(--bg-light);
    border-radius: 10px;
    font-size: 100px;
    color: var(--border-color);
}

/* Nav buttons */
.cert-nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: rgba(255,255,255,0.92);
    border: 1px solid rgba(0,0,0,0.08);
    box-shadow: 0 2px 10px rgba(0,0,0,0.14);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    color: var(--text-dark);
    transition: var(--transition-fast);
    z-index: 2;
}
.cert-nav-btn:hover { background: #fff; box-shadow: 0 4px 18px rgba(0,0,0,0.22); }
.cert-nav-btn.prev { left: 12px; }
.cert-nav-btn.next { right: 12px; }

/* Dots */
.cert-dots {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 18px;
}
.cert-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--border-color);
    border: none;
    cursor: pointer;
    transition: var(--transition-fast);
    padding: 0;
}
.cert-dot.active {
    background: var(--brand-teal);
    width: 24px;
    border-radius: 4px;
}

/* Info side */
.cert-showcase-info { padding: 10px 0; }
.cert-badge {
    display: inline-block;
    background: linear-gradient(90deg, var(--brand-teal), var(--brand-green));
    color: #fff;
    padding: 4px 14px;
    border-radius: 20px;
    font-size: 18px;
    margin-bottom: 14px;
    font-weight: 500;
    letter-spacing: 0.5px;
}
.cert-showcase-info h2 {
    font-size: 32px;
    font-weight: 700;
    color: var(--brand-navy);
    margin-bottom: 14px;
    line-height: 1.3;
}
.cert-showcase-desc {
    font-size: 20px;
    color: var(--text-light);
    line-height: 1.7;
    margin-bottom: 28px;
}
.cert-meta-list {
    border-top: 1px solid var(--border-color);
    padding-top: 20px;
}
.cert-meta-row {
    display: flex;
    gap: 16px;
    padding: 11px 0;
    border-bottom: 1px solid var(--bg-gray);
    font-size: 19px;
}
.cert-meta-label {
    color: var(--text-muted);
    min-width: 90px;
    flex-shrink: 0;
}
.cert-meta-value { color: var(--text-dark); font-weight: 500; }

/* Responsive */
@media (max-width: 900px) {
    .cert-showcase-row {
        grid-template-columns: 1fr;
        gap: 36px;
        padding: 48px 0;
    }
    .cert-showcase-row.reverse .cert-showcase-visual,
    .cert-showcase-row.reverse .cert-showcase-info { order: unset; }
    .cert-showcase-info h2 { font-size: 26px; }
}

/* ===================================
   Manufacturing Page
   =================================== */
.process-timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}
.process-step {
    display: flex;
    margin-bottom: 40px;
    position: relative;
}
.process-step.left { flex-direction: row; }
.process-step.right { flex-direction: row-reverse; }
.step-number {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--brand-green), var(--brand-green-mid));
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 42px;
    font-weight: 700;
    flex-shrink: 0;
    z-index: 1;
    box-shadow: var(--shadow-green);
}
.step-content { flex: 1; padding: 0 30px; }
.process-step.left .step-content { text-align: left; }
.process-step.right .step-content { text-align: right; }
.step-image { margin-bottom: 15px; }
.step-image img { max-width: 100%; border-radius: 8px; }
.step-content h3 {
    font-size: 27px;
    margin-bottom: 10px;
    color: var(--brand-navy);
    font-weight: 600;
}
.step-content p { color: var(--text-light); }
.process-line {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 3px;
    height: 40px;
    background: repeating-linear-gradient(
        to bottom,
        var(--brand-green) 0px,
        var(--brand-green) 6px,
        transparent 6px,
        transparent 12px
    );
    background-size: 100% 200%;
    animation: flowDown 1.5s linear infinite;
}
@keyframes flowDown {
    0%   { background-position: 0% 0%; }
    100% { background-position: 0% 200%; }
}
.step-image.svg-image { background: transparent; padding: 10px; }
.step-image.svg-image img,
.step-image.svg-image .svg-object {
    width: 100%;
    height: auto;
    max-height: 300px;
    object-fit: contain;
}
.svg-object { width: 100%; height: 300px; }

/* ===================================
   Videos Page
   =================================== */
.video-filters {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}
.videos-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 25px;
}
.video-card {
    background: var(--bg-white);
    border: 1.5px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    transition: var(--transition);
}
.video-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
    border-color: var(--brand-green);
}
.video-thumbnail {
    position: relative;
    height: 220px;
    background: var(--bg-gray);
    cursor: pointer;
    overflow: hidden;
}
.video-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}
.video-card:hover .video-thumbnail img { transform: scale(1.06); }
.video-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 72px;
    color: var(--text-muted);
}
.play-button {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    background: rgba(39, 160, 201, 0.85);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 33px;
    opacity: 0;
    transition: var(--transition);
}
.video-card:hover .play-button { opacity: 1; transform: translate(-50%, -50%) scale(1.08); }
.video-info { padding: 15px; }
.video-info h3 {
    font-size: 24px;
    margin-bottom: 8px;
    color: var(--brand-navy);
    font-weight: 600;
}
.video-info p {
    font-size: 20px;
    color: var(--text-muted);
    margin-bottom: 10px;
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}
.video-category {
    font-size: 18px;
    color: var(--brand-green);
    background: var(--brand-green-light);
    padding: 3px 10px;
    border-radius: 10px;
}

/* Video Modal */
.video-modal.active { display: flex; }
.video-modal {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(26, 44, 92, 0.92);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}
.video-modal-content {
    position: relative;
    width: 90%;
    max-width: 900px;
    aspect-ratio: 16/9;
}
.video-modal-close {
    position: absolute;
    top: -40px;
    right: 0;
    background: none;
    border: none;
    color: #fff;
    font-size: 45px;
    cursor: pointer;
    transition: var(--transition);
}
.video-modal-close:hover { color: var(--brand-green-mid); transform: scale(1.2); }
.video-embed { width: 100%; height: 100%; }
.video-embed iframe,
.video-embed video {
    width: 100%;
    height: 100%;
    border-radius: 8px;
}

/* ===================================
   News Section (Homepage)
   =================================== */
.news-section {
    padding: 60px 0;
    background: #EEF2F7;
}
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 25px;
}
.news-card {
    background: var(--bg-white);
    border: 1.5px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    transition: var(--transition);
    text-decoration: none;
    color: inherit;
    display: block;
}
.news-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
    border-color: var(--brand-green);
}
.news-image {
    height: 180px;
    background: var(--bg-gray);
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}
.news-image i { font-size: 72px; color: var(--text-muted); }
.news-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}
.news-card:hover .news-image img { transform: scale(1.06); }
.news-content { padding: 20px; }
.news-date {
    font-size: 18px;
    color: var(--brand-teal);
    margin-bottom: 8px;
    font-weight: 500;
    display: block;
}
.news-content h3 {
    font-size: 20px;
    margin-bottom: 10px;
    color: var(--brand-navy);
    font-weight: 600;
}
.news-content p {
    font-size: 21px;
    color: var(--text-light);
    margin-bottom: 15px;
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
}
.news-link {
    color: var(--brand-teal);
    font-weight: 600;
    font-size: 21px;
}
.news-link:hover { text-decoration: underline; }

/* ===================================
   General Utility
   =================================== */
.no-data {
    grid-column: 1 / -1;
    text-align: center;
    padding: 60px 20px;
    color: var(--text-muted);
}
.loading {
    grid-column: 1 / -1;
    text-align: center;
    padding: 40px;
    color: var(--text-muted);
}
.section {
    padding: 80px 0;
    background: var(--bg-white);
}

/* ===================================
   Back to Top Button
   =================================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 52px;
    height: 52px;
    background: transparent;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
    z-index: 999;
}
.back-to-top img {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    object-fit: cover;
    display: block;
    transition: transform 0.3s ease;
    box-shadow: 0 4px 16px rgba(39, 160, 201, 0.45);
}
.back-to-top::before {
    content: '';
    position: absolute;
    inset: -4px;
    border-radius: 50%;
    border: 2px solid rgba(39, 160, 201, 0.5);
    opacity: 0;
    transform: scale(0.9);
    transition: opacity 0.3s ease, transform 0.3s ease;
}
.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}
.back-to-top.visible::before {
    animation: btt-pulse 2.4s ease-out infinite;
}
@keyframes btt-pulse {
    0%   { opacity: 0.7; transform: scale(1); }
    70%  { opacity: 0;   transform: scale(1.55); }
    100% { opacity: 0;   transform: scale(1.55); }
}
.back-to-top:hover img {
    transform: translateY(-3px) scale(1.06);
    box-shadow: 0 8px 24px rgba(39, 160, 201, 0.55);
}

/* ===================================
   Responsive Sub-pages
   =================================== */
@media (max-width: 1024px) {
    .about-main { grid-template-columns: 1fr; }
    .about-stats { flex-direction: row; justify-content: center; }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .products-main { grid-template-columns: 1fr; }
    .products-sidebar { position: static; }
    .products-grid { grid-template-columns: repeat(2, 1fr); }
    .product-detail-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
    .features-grid { grid-template-columns: 1fr; }
    .products-grid { grid-template-columns: 1fr; }
    .timeline::before { left: 20px; }
    .timeline-item,
    .timeline-item:nth-child(even) {
        padding-left: 60px;
        padding-right: 0;
    }
    .timeline-year { left: 20px; transform: translateX(-50%); }
    .about-stats { flex-direction: column; }
    .page-header h1 { font-size: 48px; }
}
@media (max-width: 480px) {
    .products-filter { flex-direction: column; align-items: stretch; }
    .filter-btn { text-align: center; }
    .product-actions { flex-direction: column; }
}

/* 產品特色列表 */
.product-features { margin-top: 40px; }
.product-features h3 {
    font-size: 27px;
    font-weight: 600;
    color: var(--brand-navy);
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--brand-green);
}
.features-list { list-style: none; padding: 0; margin: 0; }
.features-list li { padding: 8px 0 8px 24px; font-size: 21px; color: var(--text-light); border-bottom: 1px solid var(--border-color); position: relative; }
.features-list li::before { content: "✓"; position: absolute; left: 0; color: var(--brand-green); font-weight: 700; }

/* Markdown description styles */
.description-md { font-size: 24px; color: var(--text-light); line-height: 1.8; margin-bottom: 30px; }
.description-md p { margin-bottom: 12px; }
.description-md ul { list-style-type: disc; padding-left: 28px; margin-bottom: 12px; }
.description-md ol { list-style-type: decimal; padding-left: 28px; margin-bottom: 12px; }
.description-md li { display: list-item; margin-bottom: 8px; }
.description-md li { margin-bottom: 6px; }
.description-md strong { font-weight: 600; color: var(--brand-navy); }
.description-md h2 { font-size: 30px; font-weight: 600; color: var(--brand-navy); border-bottom: 2px solid var(--brand-green); padding-bottom: 6px; margin: 16px 0 8px; }
.description-md h3 { font-size: 26px; font-weight: 600; color: var(--brand-navy); margin: 14px 0 6px; }
.description-md table { width: 100%; border-collapse: collapse; margin-bottom: 16px; }
.description-md table th { background: var(--brand-green-light); font-weight: 600; }
.description-md table th, .description-md table td { padding: 8px 12px; border: 1px solid var(--border-color); font-size: 22px; }
.description-md code { background: #f5f5f5; padding: 2px 6px; border-radius: 3px; font-size: 20px; }
.description-md hr { border: none; border-top: 1px solid var(--border-color); margin: 16px 0; }

/* Product watermark logo — decorative element in empty left-column space */
.product-watermark {
    position: absolute;
    bottom: 40px;
    left: 40px;
    width: 520px;
    height: 520px;
    background-image: url('/images/logo-mark.png');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: bottom left;
    opacity: 0.07;
    pointer-events: none;
    z-index: 0;
}
.video-thumbnail.no-video { cursor: default; }
.video-thumbnail.no-video:hover img { transform: none; }