/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --secondary-color: #3b82f6;
    --accent-color: #06b6d4;
    --dark-bg: #0f172a;
    --light-bg: #f8fafc;
    --text-dark: #1e293b;
    --text-light: #64748b;
    --white: #ffffff;
    --gradient: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

/* 导航栏 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    width: 36px;
    height: 36px;
    background: var(--gradient);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s;
}

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

.nav-links a:hover::after {
    width: 100%;
}

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

.nav-links a.active::after {
    width: 100%;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-btn span {
    width: 25px;
    height: 2px;
    background: var(--text-dark);
    transition: 0.3s;
}

/* 页脚 */
.footer {
    background: var(--dark-bg);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand {
    max-width: 300px;
}

.footer-brand .logo {
    color: var(--white);
    margin-bottom: 16px;
}

.footer-brand .logo-icon {
    background: var(--white);
    color: var(--primary-color);
}

.footer-brand p {
    color: #94a3b8;
    font-size: 0.9rem;
}

.footer-column h4 {
    font-size: 1rem;
    margin-bottom: 20px;
    color: var(--white);
}

.footer-column ul li {
    margin-bottom: 12px;
}

.footer-column ul li a {
    color: #94a3b8;
    font-size: 0.9rem;
    transition: color 0.3s;
}

.footer-column ul li a:hover {
    color: var(--white);
}

.footer-bottom {
    border-top: 1px solid #334155;
    padding-top: 30px;
    text-align: center;
    color: #64748b;
    font-size: 0.875rem;
}

/* 响应式 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 20px;
        gap: 20px;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    }

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

    .mobile-menu-btn {
        display: flex;
    }

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

    .footer-brand {
        grid-column: 1 / -1;
    }
}

/* 动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.animate-in {
    animation: fadeInUp 0.6s ease-out forwards;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s;
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(37, 99, 235, 0.3);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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

/* 页面头部 */
.page-header {
    background: var(--dark-bg);
    padding: 140px 0 80px;
    text-align: center;
    color: var(--white);
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.page-header p {
    color: #94a3b8;
    font-size: 1.125rem;
}

/* 区块标题 */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 2.25rem;
    color: var(--text-dark);
    margin-bottom: 16px;
}

.section-header p {
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* 工具类 */
.text-center { text-align: center; }
.mt-4 { margin-top: 1rem; }
.mt-8 { margin-top: 2rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-8 { margin-bottom: 2rem; }