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

:root {
    --primary-color: #0078d4;
    --secondary-color: #005a9e;
    --accent-color: #00bcf2;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #f5f5f5;
    --white: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
}

body {
    font-family: 'Segoe UI', 'Microsoft YaHei', 'PingFang SC', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

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

.header {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
}

.logo i {
    font-size: 32px;
}

.language-selector select {
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 14px;
    cursor: pointer;
    background: var(--white);
}

.nav {
    display: flex;
    gap: 30px;
    padding: 15px 0;
    border-top: 1px solid var(--border-color);
}

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--primary-color);
}

.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    padding: 80px 0;
    display: flex;
    align-items: center;
}

.hero .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 50px;
}

.hero-content {
    flex: 1;
}

.hero-title {
    font-size: 48px;
    font-weight: bold;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 18px;
    margin-bottom: 30px;
    opacity: 0.9;
}

.search-box {
    display: flex;
    gap: 10px;
    max-width: 500px;
}

.search-box input {
    flex: 1;
    padding: 15px 20px;
    border: none;
    border-radius: 5px;
    font-size: 16px;
}

.search-box button {
    padding: 15px 30px;
    background: var(--accent-color);
    color: var(--white);
    border: none;
    border-radius: 5px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.3s;
}

.search-box button:hover {
    background: #0096c7;
}

.hero-image {
    flex: 1;
    text-align: center;
}

.hero-image i {
    font-size: 200px;
    opacity: 0.3;
}

.categories {
    padding: 80px 0;
    background: var(--white);
}

.section-title {
    text-align: center;
    font-size: 36px;
    font-weight: bold;
    margin-bottom: 50px;
    color: var(--text-color);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.category-card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 30px;
    text-align: center;
    transition: all 0.3s;
    text-decoration: none;
    color: var(--text-color);
    box-shadow: var(--shadow);
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary-color);
}

.category-icon {
    font-size: 60px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.category-card h3 {
    font-size: 24px;
    margin-bottom: 10px;
}

.category-card p {
    color: var(--text-light);
    margin-bottom: 20px;
}

.download-btn {
    display: inline-block;
    padding: 10px 25px;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 5px;
    font-weight: bold;
    transition: background 0.3s;
}

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

.features {
    padding: 80px 0;
    background: var(--bg-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--white);
    border-radius: 10px;
    padding: 40px 30px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.feature-icon {
    font-size: 50px;
    color: var(--accent-color);
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 22px;
    margin-bottom: 15px;
    color: var(--text-color);
}

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

.latest-systems {
    padding: 80px 0;
    background: var(--white);
}

.systems-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.system-item {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 25px;
    background: var(--bg-color);
    border-radius: 10px;
    transition: all 0.3s;
}

.system-item:hover {
    background: #e8f4f8;
}

.system-icon {
    font-size: 50px;
    color: var(--primary-color);
}

.system-info {
    flex: 1;
}

.system-info h3 {
    font-size: 20px;
    margin-bottom: 5px;
}

.system-info p {
    color: var(--text-light);
    margin-bottom: 10px;
}

.download-link {
    display: inline-block;
    padding: 10px 25px;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 5px;
    font-weight: bold;
    text-decoration: none;
    transition: background 0.3s;
}

.download-link:hover {
    background: var(--secondary-color);
}

.footer {
    background: #1a1a1a;
    color: #fff;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 20px;
    font-size: 18px;
}

.footer-section p {
    color: #999;
    line-height: 1.8;
}

.footer-section ul {
    list-style: none;
}

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

.footer-section a {
    color: #999;
    text-decoration: none;
    transition: color 0.3s;
}

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

.footer-section i {
    margin-right: 8px;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #333;
    color: #666;
}

@media (max-width: 768px) {
    .hero .container {
        flex-direction: column;
        text-align: center;
    }

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

    .hero-image {
        display: none;
    }

    .nav {
        flex-wrap: wrap;
        gap: 15px;
    }

    .search-box {
        flex-direction: column;
    }

    .system-item {
        flex-direction: column;
        text-align: center;
    }

    .header-top {
        flex-direction: column;
        gap: 15px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 24px;
    }

    .hero-subtitle {
        font-size: 14px;
    }

    .section-title {
        font-size: 28px;
    }

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

.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.fade-in {
    animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.category-count {
    display: inline-block;
    background: var(--accent-color);
    color: var(--white);
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 15px;
}

.view-all {
    text-align: center;
    margin-top: 40px;
}

.btn-primary {
    display: inline-block;
    padding: 15px 40px;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 5px;
    font-weight: bold;
    text-decoration: none;
    transition: background 0.3s;
}

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

.section-description {
    text-align: center;
    color: var(--text-light);
    margin-bottom: 40px;
    font-size: 16px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.breadcrumb {
    background: var(--white);
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 30px;
}

.breadcrumb .container {
    display: flex;
    align-items: center;
    font-size: 14px;
    color: var(--text-light);
}

.breadcrumb a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s;
}

.breadcrumb a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

.breadcrumb span {
    margin: 0 8px;
    color: var(--border-color);
}

.breadcrumb .current {
    color: var(--text-color);
    font-weight: 500;
}

.breadcrumb i {
    margin-right: 5px;
    font-size: 12px;
}