/* ===== CSS Variables ===== */
:root {
    /* Light Mode Colors */
    --primary-color: #1e40af;
    --secondary-color: #3b82f6;
    --accent-color: #60a5fa;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Gradient Colors */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    
    /* Typography */
    --font-primary: 'Noto Sans TC', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-secondary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.3rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
}

/* Dark Mode Colors */
[data-theme="dark"] {
    --primary-color: #3b82f6;
    --secondary-color: #60a5fa;
    --accent-color: #93c5fd;
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    --border-color: #4b5563;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    color: var(--text-primary);
    background-color: var(--bg-primary);
    line-height: 1.6;
    transition: background-color var(--transition-base), color var(--transition-base);
    overflow-x: hidden;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

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

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all var(--transition-base);
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.9);
}

[data-theme="dark"] .navbar {
    background-color: rgba(17, 24, 39, 0.9);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) 0;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo {
    height: 40px;
    width: auto;
}

.company-name {
    font-weight: 600;
    font-size: 1rem;
    line-height: 1.2;
    white-space: nowrap; /* Prevent text from wrapping */
    min-width: 150px; /* Ensure enough space for the company name */
    display: flex;
    align-items: center;
}

.company-name small {
    font-size: 0.75rem;
    font-weight: 400;
    color: var(--text-secondary);
    margin-left: 5px; /* Add a small margin between company name and small text */
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm); /* 調整間距以避免跑版 */
    flex-wrap: nowrap; /* Ensure nav items stay in one line on PC */
}

/* PC dropdown hover effect */
@media (min-width: 1025px) {
    .nav-dropdown:hover .dropdown-content {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }
}

.nav-link {
    font-size: 0.9rem;
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.nav-link:hover {
    color: var(--primary-color);
    background-color: var(--bg-tertiary);
}

.nav-dropdown {
    position: relative;
}

.dropdown-content {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    min-width: 200px;
    padding: var(--spacing-xs);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-base);
    z-index: 100;
}

.nav-dropdown:hover .dropdown-content {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-content a {
    display: block;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    transition: all var(--transition-fast);
}

.dropdown-content a:hover {
    background-color: var(--bg-tertiary);
    color: var(--primary-color);
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.language-switcher {
    display: flex;
    gap: 0.25rem;
    background-color: var(--bg-tertiary);
    padding: 0.25rem;
    border-radius: var(--radius-md);
}

.lang-btn {
    padding: 0.375rem 0.75rem;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.lang-btn.active {
    background-color: var(--primary-color);
    color: white;
}

.lang-btn:hover:not(.active) {
    color: var(--primary-color);
}

.theme-toggle {
    padding: 0.5rem;
    border: none;
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 1.25rem;
}

.theme-toggle:hover {
    background-color: var(--primary-color);
    transform: scale(1.1);
}

.mobile-menu-toggle {
    display: none; /* Hidden by default */
    flex-direction: column;
    gap: 0.25rem;
    padding: 0.5rem;
    border: none;
    background: transparent;
    cursor: pointer;
    z-index: 1001; /* Ensure toggle is above other elements */
}

@media (max-width: 1024px) {
    .mobile-menu-toggle {
        display: flex; /* Show on small screens */
        align-items: center;
        justify-content: center;
    }
}

@media (min-width: 1025px) {
    .mobile-menu-toggle {
        display: none; /* Hide on larger screens */
    }
}

@media (max-width: 1024px) {
    .nav-menu {
        display: none; /* Hidden by default */
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--bg-primary);
        border-top: 1px solid var(--border-color);
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-md) 0;
        transition: all var(--transition-base);
        opacity: 0;
        visibility: hidden;
        transform: translateY(-10px);
    }

    .nav-menu.active {
        display: flex; /* Show when active */
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }

    .nav-menu .nav-link, .nav-menu .nav-dropdown > .nav-link {
        width: 100%;
        padding: var(--spacing-sm) var(--spacing-md);
        text-align: center;
    }

    .nav-dropdown .dropdown-content {
        position: static;
        width: 100%;
        box-shadow: none;
        border: none;
        padding: 0;
        background-color: var(--bg-secondary);
        opacity: 0;
        visibility: hidden;
        height: 0;
        overflow: hidden;
        transition: all var(--transition-base);
        margin-top: var(--spacing-xs);
    }

    .nav-dropdown.active .dropdown-content {
        opacity: 1;
        visibility: visible;
        height: auto;
        display: flex;
        flex-direction: column;
    }

    .nav-dropdown .dropdown-content a {
        padding-left: var(--spacing-lg);
    }

    .nav-controls {
        gap: var(--spacing-xs);
    }

    .language-switcher {
        padding: 0.125rem;
    }

    .lang-btn {
        padding: 0.25rem 0.5rem;
        font-size: 0.8rem;
    }

    .theme-toggle {
        padding: 0.375rem;
        font-size: 1rem;
    }

    .nav-wrapper {
        padding: var(--spacing-xs) 0;
    }

    .nav-logo .logo {
        height: 32px;
    }

    .company-name {
        font-size: 0.9rem;
    }

    .company-name small {
        font-size: 0.65rem;
    }
}

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

/* ===== Hero Section ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient-hero);
    opacity: 0.1;
    z-index: -1;
}

[data-theme="dark"] .hero-bg {
    opacity: 0.2;
}

.hero-content {
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
    padding: var(--spacing-2xl) 0;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 900;
    margin-bottom: var(--spacing-md);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1.25rem, 2.5vw, 1.75rem);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
}

.hero-description {
    font-size: clamp(1rem, 1.5vw, 1.125rem);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
}

.scroll-indicator span {
    display: block;
    width: 24px;
    height: 40px;
    border: 2px solid var(--primary-color);
    border-radius: 12px;
    position: relative;
}

.scroll-indicator span::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background-color: var(--primary-color);
    border-radius: 2px;
    animation: scroll 2s infinite;
}

@keyframes scroll {
    0%, 100% {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }
    50% {
        transform: translateX(-50%) translateY(12px);
        opacity: 0.5;
    }
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    border: 2px solid transparent;
    text-align: center;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: white;
}

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

.btn-outline:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

/* ===== Sections ===== */
.section {
    padding: var(--spacing-2xl) 0;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 800;
    text-align: center;
    margin-bottom: var(--spacing-xl);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===== Mission Section ===== */
.mission-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.mission-card {
    background-color: var(--bg-secondary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    text-align: center;
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

.mission-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.mission-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.mission-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.mission-card p {
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ===== Capabilities Section ===== */
.capabilities {
    background-color: var(--bg-secondary);
}

.capabilities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.capability-item {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.capability-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.capability-number {
    font-size: 2rem;
    font-weight: 900;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.capability-item h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.capability-item p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===== About GAS Section ===== */
.about-gas-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: start;
}

.about-gas-text h3 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.about-gas-text p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.feature-box {
    background: var(--gradient-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    color: white;
}

.feature-box h4 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.feature-box ul {
    list-style: none;
}

.feature-box li {
    padding: var(--spacing-xs) 0;
    padding-left: var(--spacing-md);
    position: relative;
}

.feature-box li::before {
    content: '✓';
    position: absolute;
    left: 0;
    font-weight: bold;
}

/* ===== Products Section ===== */
.products {
    background-color: var(--bg-secondary);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.product-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.product-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: var(--spacing-md);
}

.product-header h3 {
    font-size: 1.5rem;
    font-weight: 700;
}

.product-tag {
    background: var(--gradient-primary);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-md);
    font-size: 0.75rem;
    font-weight: 600;
}

.product-desc {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
}

.product-features {
    list-style: none;
    margin-bottom: var(--spacing-lg);
    flex-grow: 1;
}

.product-features li {
    padding: var(--spacing-xs) 0;
    padding-left: var(--spacing-md);
    position: relative;
    color: var(--text-secondary);
}

.product-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* ===== Solutions Section ===== */
.solutions-tabs {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.tab-btn {
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--border-color);
    background-color: transparent;
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-base);
}

.tab-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.tab-btn.active {
    background: var(--gradient-primary);
    color: white;
    border-color: transparent;
}

.tab-content {
    display: none;
    animation: fadeIn var(--transition-base);
}

.tab-content.active {
    display: block;
}

.solution-detail {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-xl);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-xl);
}

.solution-detail h3 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.solution-detail p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.solution-features {
    list-style: none;
}

.solution-features li {
    padding: var(--spacing-xs) 0;
    padding-left: var(--spacing-md);
    position: relative;
    color: var(--text-secondary);
}

.solution-features li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* ===== Insights Section ===== */
.insights {
    background-color: var(--bg-secondary);
}

.insights-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.insight-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.insight-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.insight-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.insight-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.insight-card p {
    color: var(--text-secondary);
}

/* ===== Learning Section ===== */
.learning-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.learning-card {
    background-color: var(--bg-secondary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.learning-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.learning-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.learning-card p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.learn-more {
    color: var(--primary-color);
    font-weight: 600;
    transition: all var(--transition-fast);
}

.learn-more:hover {
    transform: translateX(4px);
    display: inline-block;
}

/* ===== Pricing Section ===== */
.pricing {
    background-color: var(--bg-secondary);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.pricing-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 2px solid var(--border-color);
    text-align: center;
    transition: all var(--transition-base);
    position: relative;
}

.pricing-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.pricing-card.featured {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.featured-badge {
    position: absolute;
    top: -12px;
    right: var(--spacing-lg);
    background: var(--gradient-primary);
    color: white;
    padding: 0.375rem 1rem;
    border-radius: var(--radius-lg);
    font-size: 0.875rem;
    font-weight: 700;
}

.pricing-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.price {
    margin-bottom: var(--spacing-lg);
}

.currency {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.amount {
    font-size: 3rem;
    font-weight: 900;
    color: var(--primary-color);
}

.period {
    font-size: 1rem;
    color: var(--text-secondary);
}

.pricing-features {
    list-style: none;
    margin-bottom: var(--spacing-xl);
    text-align: left;
}

.pricing-features li {
    padding: var(--spacing-xs) 0;
    padding-left: var(--spacing-md);
    position: relative;
    color: var(--text-secondary);
}

.pricing-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* ===== About Section ===== */
.about-text h3 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.about-text h3:first-child {
    margin-top: 0;
}

.about-text p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

/* Removed duplicate founder-info styles - using enhanced version below */

/* ===== Contact Section ===== */
.contact {
    background-color: var(--bg-secondary);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.contact-item {
    display: flex;
    gap: var(--spacing-md);
    align-items: start;
}

.contact-icon {
    font-size: 2rem;
}

.contact-item h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.contact-item p {
    color: var(--text-secondary);
}

.line-qr {
    width: 150px;
    height: 150px;
    margin-top: var(--spacing-sm);
}

.contact-form {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.875rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-group textarea {
    resize: vertical;
}

/* ===== Footer ===== */
.footer {
    background-color: var(--bg-tertiary);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.footer-section p,
.footer-section a {
    display: block;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.footer-bottom p {
    color: var(--text-secondary);
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-links a {
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
    .nav-menu {
        display: none;
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background-color: var(--bg-primary);
        border-bottom: 1px solid var(--border-color);
        flex-direction: column;
        padding: var(--spacing-md);
        box-shadow: var(--shadow-lg);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .nav-dropdown .dropdown-content {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        border: none;
        box-shadow: none;
        padding-left: var(--spacing-md);
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .about-gas-content,
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    /* Founder mobile styles handled in enhanced section below */
}

@media (max-width: 768px) {
    html {
        font-size: 14px;
    }
    
    .hero {
        min-height: 90vh;
        padding-top: 60px;
    }
    
    .hero-content {
        padding: var(--spacing-lg) 0;
        max-width: 100%;
    }
    
    .hero-title {
        font-size: clamp(2rem, 6vw, 3rem);
        margin-bottom: var(--spacing-sm);
        line-height: 1.2;
    }
    
    .hero-subtitle {
        font-size: clamp(1rem, 3vw, 1.5rem);
        margin-bottom: var(--spacing-md);
        line-height: 1.4;
    }
    
    .hero-description {
        font-size: clamp(0.9rem, 2vw, 1rem);
        margin-bottom: var(--spacing-lg);
        line-height: 1.6;
        padding: 0 var(--spacing-sm);
    }
    
    .hero-cta {
        flex-direction: column;
        gap: var(--spacing-sm);
        align-items: center;
    }
    
    .solutions-tabs {
        flex-direction: column;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero {
        min-height: 85vh;
        padding-top: 50px;
    }
    
    .hero-content {
        padding: var(--spacing-md) 0;
    }
    
    .hero-title {
        font-size: clamp(1.75rem, 7vw, 2.5rem);
        margin-bottom: var(--spacing-xs);
    }
    
    .hero-subtitle {
        font-size: clamp(0.9rem, 4vw, 1.25rem);
        margin-bottom: var(--spacing-sm);
    }
    
    .hero-description {
        font-size: clamp(0.85rem, 3vw, 0.95rem);
        margin-bottom: var(--spacing-md);
        padding: 0 var(--spacing-xs);
    }
    
    .company-name {
        display: none;
    }
    
    .pricing-grid,
    .products-grid {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: clamp(1.5rem, 5vw, 2rem);
        margin-bottom: var(--spacing-md);
    }
    
    .section {
        padding: var(--spacing-lg) 0;
    }
}


.no-scroll {
    overflow: hidden;
}



/* ===== About Section Tabs ===== */
.about-tabs {
    display: flex;
    justify-content: center;
    margin-bottom: var(--spacing-xl);
    border-bottom: 2px solid var(--border-color);
}

.tab-btn {
    background: none;
    border: none;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-base);
    border-bottom: 3px solid transparent;
    position: relative;
}

.tab-btn:hover {
    color: var(--primary-color);
    background-color: var(--bg-secondary);
}

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
    font-weight: 600;
}

.tab-content {
    display: none;
    animation: fadeInUp 0.6s ease-out;
}

.tab-content.active {
    display: block;
}

/* Company Stats */
.company-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
    padding: var(--spacing-xl);
    background: var(--gradient-accent);
    border-radius: var(--radius-xl);
    color: white;
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.9;
}

/* GAS Modules Grid */
.gas-modules {
    margin: var(--spacing-xl) 0;
}

.modules-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.module-item {
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
    transition: all var(--transition-base);
}

.module-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.module-item h5 {
    color: var(--primary-color);
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
}

.module-item p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* GAS Architecture */
.gas-architecture {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
    margin: var(--spacing-xl) 0;
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
}

.architecture-img {
    width: 100%;
    border-radius: var(--radius-lg);
}

.architecture-text h4 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.architecture-text ul {
    list-style: none;
    margin-top: var(--spacing-md);
}

.architecture-text li {
    margin-bottom: var(--spacing-sm);
    padding-left: var(--spacing-md);
    position: relative;
}

.architecture-text li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Patent Technology */
.patent-list {
    display: grid;
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
}

.patent-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
}

.patent-item:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-md);
}

.patent-icon {
    font-size: 2.5rem;
    min-width: 60px;
    text-align: center;
}

.patent-content h4 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.patent-content p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.patent-image {
    text-align: center;
    margin-top: var(--spacing-xl);
}

.patent-img {
    max-width: 80%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

/* Responsive Design for About Section */
@media (max-width: 768px) {
    .about-tabs {
        flex-direction: column;
        border-bottom: none;
    }
    
    .tab-btn {
        border-bottom: none;
        border-left: 3px solid transparent;
        text-align: left;
    }
    
    .tab-btn.active {
        border-left-color: var(--primary-color);
        border-bottom-color: transparent;
        background-color: var(--bg-secondary);
    }
    
    .company-stats {
        grid-template-columns: 1fr;
        padding: var(--spacing-lg);
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .modules-grid {
        grid-template-columns: 1fr;
    }
    
    .gas-architecture {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .patent-item {
        flex-direction: column;
        text-align: center;
    }
    
    .patent-icon {
        min-width: auto;
    }
}

/* Enhanced animations for tab content */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Language switcher enhancement */
.language-switcher {
    display: flex;
    gap: var(--spacing-xs);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xs);
}

.lang-btn {
    background: none;
    border: none;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
    min-width: 40px;
}

.lang-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.lang-btn.active {
    background: var(--primary-color);
    color: white;
}

/* Enhanced founder info section */
.founder-info {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--spacing-lg);
    align-items: center;
    margin-top: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
}

.founder-img {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--primary-color);
}

.founder-text h4 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.founder-name {
    font-weight: 600;
    color: var(--primary-color);
    margin-top: var(--spacing-md);
}

@media (max-width: 768px) {
    .founder-info {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .founder-img {
        justify-self: center;
    }
}