/* CSS Variables */
.eu-carbon {
    --primary-color: #16a34a;
    --primary-dark: #15803d;
    --primary-light: #22c55e;
    --secondary-color: #1a73e8;
    --accent-color: #ea4335;
    --dark-color: #202124;
    --gray-900: #202124;
    --gray-800: #3c4043;
    --gray-700: #5f6368;
    --gray-600: #80868b;
    --gray-500: #9aa0a6;
    --gray-400: #bdc1c6;
    --gray-300: #dadce0;
    --gray-200: #e8eaed;
    --gray-100: #f8f9fa;
    --white: #ffffff;
    --shadow-sm: 0 1px 2px 0 rgba(60,64,67,0.3), 0 1px 3px 1px rgba(60,64,67,0.15);
    --shadow-md: 0 1px 3px 0 rgba(60,64,67,0.3), 0 4px 8px 3px rgba(60,64,67,0.15);
    --shadow-lg: 0 1px 3px 0 rgba(60,64,67,0.3), 0 8px 16px 4px rgba(60,64,67,0.15);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s ease;
}

/* Reset & Base - 只影响 eu-carbon 内部 */
.eu-carbon *,
.eu-carbon *::before,
.eu-carbon *::after {
    box-sizing: border-box;
}

.eu-carbon {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--white);
}

.eu-carbon a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

.eu-carbon a:hover {
    color: var(--primary-dark);
}

/* Container */
.eu-carbon .container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===================================
   导航栏
   =================================== */
.eu-carbon .navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--white);
    border-bottom: 1px solid var(--gray-300);
    z-index: 1000;
    transition: var(--transition);
}

.eu-carbon .nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
}

.eu-carbon .nav-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 1.2rem;
    color: var(--primary-color);
    text-decoration: none;
}

.eu-carbon .logo-badge {
    width: 32px;
    height: 32px;
    border-radius: 6px;
    background: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
}

.eu-carbon .logo-badge-text {
    color: white;
    font-weight: bold;
    font-size: 12px;
}

.eu-carbon .logo-text {
    color: var(--gray-900);
    font-weight: 600;
}

.eu-carbon .nav-menu {
    display: flex;
    gap: 4px;
    list-style: none;
    padding: 0;
    margin: 0;
}

.eu-carbon .nav-item {
    position: relative;
}

.eu-carbon .nav-link {
    padding: 8px 14px;
    border-radius: var(--radius-md);
    color: var(--gray-800);
    font-weight: 500;
    font-size: 0.9rem;
    transition: var(--transition);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 4px;
}

.eu-carbon .nav-link:hover {
    background: var(--gray-100);
    color: var(--primary-color);
}

.eu-carbon .nav-link::after {
    content: '';
    width: 0;
    height: 0;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-top: 4px solid currentColor;
    opacity: 0.5;
    transition: var(--transition);
}

.eu-carbon .nav-item:hover .nav-link::after {
    transform: rotate(180deg);
}

/* Dropdown */
.eu-carbon .dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 200px;
    background: var(--white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: var(--transition);
    padding: 8px 0;
    z-index: 100;
}

.eu-carbon .nav-item:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.eu-carbon .dropdown-menu a {
    display: block;
    padding: 10px 16px;
    color: var(--gray-700);
    font-size: 0.9rem;
    transition: var(--transition);
}

.eu-carbon .dropdown-menu a:hover {
    background: var(--gray-100);
    color: var(--primary-color);
}

.eu-carbon .nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
    background: none;
    border: none;
    cursor: pointer;
}

.eu-carbon .nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--gray-800);
    transition: var(--transition);
}

/* ===================================
   面包屑导航
   =================================== */
.eu-carbon .breadcrumb {
    padding: 8px 0;
    background: var(--gray-100);
    border-bottom: 1px solid var(--gray-200);
    margin-top: 60px;
    position: sticky;
    top: 60px;
    z-index: 999;
}

.eu-carbon .breadcrumb-list {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
    list-style: none;
    padding: 0;
    margin: 0;
    font-size: 0.85rem;
}

.eu-carbon .breadcrumb-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.eu-carbon .breadcrumb-item a {
    color: var(--gray-600);
    text-decoration: none;
    transition: var(--transition);
}

.eu-carbon .breadcrumb-item a:hover {
    color: var(--primary-color);
}

.eu-carbon .breadcrumb-item.active {
    color: var(--gray-800);
    font-weight: 500;
}

.eu-carbon .breadcrumb-separator {
    color: var(--gray-400);
}

/* ===================================
   Hero 区域
   =================================== */
.eu-carbon .hero {
    padding: 140px 0 80px;
    background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
}

.eu-carbon .hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.eu-carbon .hero-title {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    color: var(--gray-900);
    margin-bottom: 24px;
}

.eu-carbon .hero-title .highlight {
    color: var(--primary-color);
}

.eu-carbon .hero-subtitle {
    font-size: 20px;
    color: var(--gray-700);
    margin-bottom: 40px;
}

.eu-carbon .hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.eu-carbon .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-size: 16px;
    font-weight: 500;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    border: 2px solid transparent;
}

.eu-carbon .btn-primary {
    background: var(--primary-color);
    color: var(--white);
}

.eu-carbon .btn-primary:hover {
    background: var(--primary-dark);
    color: var(--white);
    box-shadow: var(--shadow-md);
}

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

.eu-carbon .btn-outline:hover {
    background: var(--primary-color);
    color: var(--white);
}

.eu-carbon .btn-large {
    padding: 16px 32px;
    font-size: 18px;
}

/* ===================================
   卡片区
   =================================== */
.eu-carbon .section {
    padding: 80px 0;
}

.eu-carbon .section-title {
    font-size: 32px;
    font-weight: 600;
    text-align: center;
    color: var(--gray-900);
    margin-bottom: 48px;
}

.eu-carbon .cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.eu-carbon .card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--gray-200);
}

.eu-carbon .card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
    border-color: var(--primary-light);
}

.eu-carbon .card-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

.eu-carbon .card-title {
    font-size: 22px;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.eu-carbon .card-text {
    color: var(--gray-700);
    font-size: 15px;
    margin-bottom: 20px;
    line-height: 1.7;
}

.eu-carbon .card-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--primary-color);
    font-weight: 500;
    font-size: 15px;
}

.eu-carbon .card-link:hover {
    color: var(--primary-dark);
}

/* ===================================
   页脚
   =================================== */
.eu-carbon .footer {
    background: #f5f7f9;
    color: #333333;
    padding: 50px 0 20px;
}

.eu-carbon .footer-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 32px;
}

.eu-carbon .footer-brand {
    max-width: 320px;
}

.eu-carbon .footer-brand-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 16px;
    text-decoration: none;
}

.eu-carbon .footer-brand .logo-badge {
    width: 32px;
    height: 32px;
    border-radius: 6px;
    background: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
}

.eu-carbon .footer-brand .logo-badge-text {
    color: white;
    font-weight: bold;
    font-size: 12px;
}

.eu-carbon .footer-brand .logo-text {
    font-size: 1.15rem;
    font-weight: 600;
    color: #222222;
}

.eu-carbon .footer-brand > p {
    color: #666666;
    font-size: 0.9rem;
    line-height: 1.7;
    margin-bottom: 12px;
}

.eu-carbon .footer-brand .brand-note {
    color: #718096;
    font-size: 12px;
}

.eu-carbon .footer-brand .brand-note a {
    color: var(--primary-color);
}

.eu-carbon .footer-brand .brand-note a:hover {
    text-decoration: underline;
}

.eu-carbon .footer-links h4 {
    font-size: 0.95rem;
    margin-bottom: 14px;
    font-weight: 600;
    color: #222222;
}

.eu-carbon .footer-links ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.eu-carbon .footer-links ul li {
    margin-bottom: 8px;
}

.eu-carbon .footer-links a {
    color: #333333;
    font-size: 0.85rem;
    transition: var(--transition);
}

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

.eu-carbon .footer-bottom {
    padding-top: 20px;
    border-top: 1px solid #e0e0e0;
    text-align: center;
    color: #666666;
    font-size: 0.8rem;
}

/* ===================================
   响应式设计
   =================================== */
@media (max-width: 1024px) {
    .eu-carbon .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .eu-carbon .nav-menu {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 16px;
        box-shadow: var(--shadow-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

    .eu-carbon .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .eu-carbon .nav-toggle {
        display: flex;
    }

    .eu-carbon .dropdown-menu {
        position: static;
        box-shadow: none;
        opacity: 1;
        visibility: visible;
        transform: none;
        padding-left: 16px;
        display: none;
    }

    .eu-carbon .nav-item.active .dropdown-menu {
        display: block;
    }

    .eu-carbon .hero {
        padding: 100px 0 60px;
    }

    .eu-carbon .hero-title {
        font-size: 32px;
    }

    .eu-carbon .hero-subtitle {
        font-size: 16px;
    }

    .eu-carbon .section {
        padding: 48px 0;
    }

    .eu-carbon .section-title {
        font-size: 24px;
    }

    .eu-carbon .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .eu-carbon .container {
        padding: 0 16px;
    }

    .eu-carbon .cards-grid {
        grid-template-columns: 1fr;
    }
}