/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #10b981;
    --dark-color: #1f2937;
    --light-color: #f9fafb;
    --gray-color: #6b7280;
    --gray-light: #e5e7eb;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --success-color: #10b981;

    --font-primary: 'Inter', sans-serif;
    --font-mono: 'Roboto Mono', monospace;

    --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);

    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

body {
    font-family: var(--font-primary);
    line-height: 1.6;
    color: var(--dark-color);
    background-color: var(--light-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* 导航栏样式 */
.navbar {
    background-color: white;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-brand i {
    font-size: 1.75rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--dark-color);
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
    transition: color 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

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

.nav-menu a.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background-color: var(--primary-color);
    border-radius: 1px;
}

.nav-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--dark-color);
}

/* 英雄区域样式 */
.hero {
    padding: 5rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
}

.stat {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
}

.stat i {
    font-size: 1.5rem;
    color: var(--secondary-color);
}

.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background-color: #0da271;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.ai-visual {
    position: relative;
    height: 300px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    backdrop-filter: blur(10px);
    overflow: hidden;
}

.neural-network {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(255,255,255,0.2) 0%, rgba(255,255,255,0) 70%);
}

.floating-elements {
    position: absolute;
    width: 100%;
    height: 100%;
}

.element {
    position: absolute;
    width: 50px;
    height: 50px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    animation: float 6s ease-in-out infinite;
}

.element-1 {
    top: 20%;
    left: 20%;
    animation-delay: 0s;
}

.element-2 {
    top: 60%;
    right: 20%;
    animation-delay: 2s;
}

.element-3 {
    bottom: 20%;
    left: 40%;
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) rotate(0deg);
    }
    50% {
        transform: translateY(-20px) rotate(180deg);
    }
}

/* 功能区域样式 */
.features {
    padding: 5rem 0;
    background-color: white;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--dark-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid var(--gray-light);
}

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

.feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: white;
    font-size: 1.5rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.feature-card p {
    color: var(--gray-color);
    margin-bottom: 1.5rem;
}

.feature-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: gap 0.3s ease;
}

.feature-link:hover {
    gap: 1rem;
}

/* 资讯预览样式 */
.news-preview {
    padding: 5rem 0;
    background-color: var(--light-color);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.view-all {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: gap 0.3s ease;
}

.view-all:hover {
    gap: 1rem;
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.news-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: transform 0.3s ease;
    border: 1px solid var(--gray-light);
}

.news-card:hover {
    transform: translateY(-5px);
}

.news-category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.news-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.news-excerpt {
    color: var(--gray-color);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.news-meta {
    display: flex;
    gap: 1rem;
    color: var(--gray-color);
    font-size: 0.875rem;
}

.news-meta span {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

/* AI模型预览样式 */
.models-preview {
    padding: 5rem 0;
    background-color: white;
}

.models-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.model-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: transform 0.3s ease;
    border: 1px solid var(--gray-light);
}

.model-card:hover {
    transform: translateY(-5px);
}

.model-logo {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    margin: 0 auto 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
}

.model-logo.gpt {
    background: linear-gradient(135deg, #10a37f, #1a7f64);
}

.model-logo.claude {
    background: linear-gradient(135deg, #6366f1, #4f46e5);
}

.model-logo.gemini {
    background: linear-gradient(135deg, #4285f4, #34a853);
}

.model-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.model-desc {
    color: var(--gray-color);
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

.model-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
}

.tag {
    padding: 0.25rem 0.75rem;
    background-color: var(--gray-light);
    color: var(--gray-color);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
}

/* 新闻页面样式 */
.page-header {
    padding: 4rem 0 2rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.page-header h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.page-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.category-filter {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.category-btn {
    padding: 0.5rem 1.5rem;
    background-color: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.category-btn:hover {
    background-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

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

.news-list {
    padding: 4rem 0;
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.news-card.detailed {
    background-color: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
}

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

.news-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.news-category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
}

.news-date {
    color: var(--gray-color);
    font-size: 0.875rem;
}

.news-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.news-excerpt {
    color: var(--gray-color);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.news-content {
    color: var(--dark-color);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.news-content p {
    margin-bottom: 1rem;
}

.news-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1.5rem;
    border-top: 1px solid var(--gray-light);
}

.news-meta {
    display: flex;
    gap: 1.5rem;
    color: var(--gray-color);
    font-size: 0.875rem;
}

.read-more {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: gap 0.3s ease;
}

.read-more:hover {
    gap: 0.75rem;
}

.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin-top: 3rem;
}

.page-btn {
    padding: 0.5rem 1rem;
    background-color: white;
    border: 1px solid var(--gray-light);
    border-radius: var(--radius-md);
    color: var(--dark-color);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.page-btn:hover:not(.disabled) {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.page-btn.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.page-numbers {
    display: flex;
    gap: 0.5rem;
}

.page-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background-color: white;
    border: 1px solid var(--gray-light);
    color: var(--dark-color);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
}

.page-number:hover,
.page-number.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.page-dots {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    color: var(--gray-color);
}

.newsletter {
    padding: 4rem 0;
    background-color: var(--light-color);
    text-align: center;
}

.newsletter-content h2 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.newsletter-content p {
    color: var(--gray-color);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.newsletter-form {
    display: flex;
    max-width: 500px;
    margin: 0 auto 1rem;
    gap: 1rem;
}

.newsletter-form input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 1px solid var(--gray-light);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.newsletter-form input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.newsletter-note {
    font-size: 0.875rem;
    color: var(--gray-color);
}

/* 模型页面样式 */
.model-categories {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.model-comparison {
    padding: 4rem 0;
    background-color: var(--light-color);
}

.comparison-table-container {
    overflow-x: auto;
    margin-top: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.comparison-table {
    width: 100%;
    border-collapse: collapse;
    background-color: white;
}

.comparison-table th {
    background-color: var(--primary-color);
    color: white;
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    white-space: nowrap;
}

.comparison-table td {
    padding: 1rem;
    border-bottom: 1px solid var(--gray-light);
}

.comparison-table tbody tr:hover {
    background-color: var(--light-color);
}

.comparison-table tbody tr:last-child td {
    border-bottom: none;
}

.model-details {
    padding: 4rem 0;
}

.models-grid.detailed {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.model-card.detailed {
    background-color: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

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

.model-header {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.model-logo {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
}

.model-logo.gpt {
    background: linear-gradient(135deg, #10a37f 0%, #1a7f64 100%);
}

.model-logo.claude {
    background: linear-gradient(135deg, #d946ef 0%, #a855f7 100%);
}

.model-logo.gemini {
    background: linear-gradient(135deg, #4285f4 0%, #34a853 100%);
}

.model-logo.llama {
    background: linear-gradient(135deg, #1877f2 0%, #42b72a 100%);
}

.model-info {
    flex: 1;
}

.model-name {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.model-company {
    color: var(--gray-color);
    font-size: 0.875rem;
}

.model-description {
    color: var(--dark-color);
    line-height: 1.6;
}

.model-specs {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    padding: 1rem;
    background-color: var(--light-color);
    border-radius: var(--radius-md);
}

.spec {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.spec-label {
    font-size: 0.875rem;
    color: var(--gray-color);
}

.spec-value {
    font-weight: 600;
    color: var(--dark-color);
}

.model-features h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.model-features ul {
    list-style: none;
    padding-left: 0;
}

.model-features li {
    padding: 0.25rem 0;
    color: var(--dark-color);
    position: relative;
    padding-left: 1.5rem;
}

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

.model-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--light-color);
    color: var(--dark-color);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
}

.model-links {
    display: flex;
    gap: 1rem;
    margin-top: auto;
}

.model-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-md);
    font-weight: 500;
    transition: all 0.3s ease;
}

.model-link:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
}

.model-guide {
    padding: 4rem 0;
    background-color: var(--light-color);
}

.guide-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.guide-card {
    background-color: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
}

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

.guide-icon {
    width: 60px;
    height: 60px;
    background-color: var(--primary-color);
    color: white;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.guide-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.guide-card p {
    color: var(--gray-color);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.guide-models {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.model-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    color: white;
}

.model-badge.gpt {
    background-color: #10a37f;
}

.model-badge.claude {
    background-color: #d946ef;
}

.model-badge.gemini {
    background-color: #4285f4;
}

.model-badge.copilot {
    background-color: #6e40c9;
}

.model-badge.dalle {
    background-color: #10a37f;
}

/* 国旗图标样式 */
.country-flag {
    display: inline-block;
    font-size: 1.2em;
    margin-right: 0.5rem;
    vertical-align: middle;
}

.country-flag.us {
    /* 美国国旗样式 */
}

.country-flag.cn {
    /* 中国国旗样式 */
}

/* 模型卡片中的国家信息 */
.model-country {
    font-size: 0.875rem;
    color: var(--gray-color);
    margin-top: 0.25rem;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

/* 国内模型logo样式 */
.model-logo.wenxin {
    background: linear-gradient(135deg, #4e54c8 0%, #8f94fb 100%);
}

.model-logo.tongyi {
    background: linear-gradient(135deg, #ff6b6b 0%, #ff8e53 100%);
}

.model-logo.glm {
    background: linear-gradient(135deg, #00b09b 0%, #96c93d 100%);
}

.model-logo.tencent {
    background: linear-gradient(135deg, #0088cc 0%, #00aaff 100%);
}

.model-logo.kimi {
    background: linear-gradient(135deg, #8a2be2 0%, #9370db 100%);
}

/* 国家筛选按钮 */
.country-filter {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1.5rem;
    flex-wrap: wrap;
}

.country-filter-btn {
    padding: 0.5rem 1.5rem;
    background-color: var(--light-color);
    border: 1px solid var(--gray-light);
    color: var(--dark-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.country-filter-btn:hover {
    background-color: var(--gray-light);
    transform: translateY(-2px);
}

.country-filter-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* 表格中的国家列 */
.comparison-table td:nth-child(2) {
    white-space: nowrap;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .country-filter {
        gap: 0.5rem;
    }

    .country-filter-btn {
        padding: 0.5rem 1rem;
        font-size: 0.875rem;
    }

    .comparison-table td:nth-child(2) {
        font-size: 0.875rem;
    }
}

/* 教程页面样式 */
.learning-path {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 3rem;
    flex-wrap: wrap;
}

.path-step {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.5rem;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.3s ease;
    min-width: 180px;
}

.path-step:hover {
    background-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.path-step.active {
    background-color: white;
    color: var(--primary-color);
}

.step-number {
    width: 40px;
    height: 40px;
    background-color: var(--secondary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
}

.path-step.active .step-number {
    background-color: var(--primary-color);
}

.step-content h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.step-content p {
    font-size: 0.875rem;
    opacity: 0.9;
}

.tutorial-categories {
    padding: 4rem 0;
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.category-card {
    background-color: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    cursor: pointer;
    text-align: center;
}

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

.category-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    margin: 0 auto 1.5rem;
}

.category-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.category-card p {
    color: var(--gray-color);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.category-stats {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--gray-color);
    font-size: 0.875rem;
}

.category-link {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-md);
    font-weight: 500;
    transition: all 0.3s ease;
}

.category-link:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
}

.popular-tutorials {
    padding: 4rem 0;
    background-color: var(--light-color);
}

.tutorials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.tutorial-card {
    background-color: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    cursor: pointer;
}

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

.tutorial-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.tutorial-level {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
}

.tutorial-level.beginner {
    background-color: var(--success-color);
    color: white;
}

.tutorial-level.intermediate {
    background-color: var(--warning-color);
    color: white;
}

.tutorial-level.advanced {
    background-color: var(--danger-color);
    color: white;
}

.tutorial-rating {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    color: var(--warning-color);
    font-weight: 600;
}

.tutorial-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.4;
}

.tutorial-description {
    color: var(--gray-color);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.tutorial-meta {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1rem;
    color: var(--gray-color);
    font-size: 0.875rem;
}

.tutorial-progress {
    margin-bottom: 1.5rem;
}

.progress-bar {
    height: 8px;
    background-color: var(--gray-light);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 4px;
}

.progress-text {
    font-size: 0.875rem;
    color: var(--gray-color);
}

.tutorial-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: gap 0.3s ease;
}

.tutorial-link:hover {
    gap: 0.75rem;
}

.roadmap {
    padding: 4rem 0;
}

.roadmap-container {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-top: 2rem;
}

.roadmap-phase {
    background-color: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    cursor: pointer;
}

.roadmap-phase:hover {
    box-shadow: var(--shadow-lg);
}

.phase-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.phase-number {
    width: 40px;
    height: 40px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
}

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

.phase-topics {
    list-style: none;
    padding-left: 0;
    margin-bottom: 1.5rem;
}

.phase-topics li {
    padding: 0.5rem 0;
    color: var(--dark-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.phase-topics li i {
    color: var(--success-color);
}

.phase-resources h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.resources-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.resource-link {
    display: inline-block;
    padding: 0.5rem 1rem;
    background-color: var(--light-color);
    color: var(--dark-color);
    text-decoration: none;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    transition: all 0.3s ease;
}

.resource-link:hover {
    background-color: var(--primary-color);
    color: white;
}

.learning-community {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.community-content h2 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.community-content p {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.community-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin: 3rem 0;
    flex-wrap: wrap;
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1.125rem;
    opacity: 0.9;
}

.learning-community .btn {
    background-color: white;
    color: var(--primary-color);
    font-size: 1.125rem;
    padding: 1rem 2.5rem;
}

.learning-community .btn:hover {
    background-color: var(--light-color);
    transform: translateY(-2px);
}

/* 页脚样式 */
.footer {
    background-color: var(--dark-color);
    color: white;
    padding: 4rem 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: white;
}

.footer-description {
    color: #9ca3af;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: #374151;
    border-radius: 50%;
    color: white;
    text-decoration: none;
    transition: background-color 0.3s ease;
}

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

.footer-section h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: white;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    color: #9ca3af;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: white;
}

.footer-contact {
    list-style: none;
}

.footer-contact li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    color: #9ca3af;
}

.footer-contact i {
    color: var(--primary-color);
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid #374151;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-bottom p {
    color: #9ca3af;
}

.footer-legal {
    display: flex;
    gap: 1.5rem;
}

.footer-legal a {
    color: #9ca3af;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-legal a:hover {
    color: white;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: white;
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow-lg);
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-toggle {
        display: block;
    }

    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }

    .hero-stats {
        justify-content: center;
        flex-wrap: wrap;
    }

    .section-title {
        font-size: 2rem;
    }

    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

    .footer-legal {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }

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

    .feature-card,
    .news-card,
    .model-card {
        padding: 1.5rem;
    }
}