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

:root {
    --primary: #667eea;
    --primary-dark: #5a6fd8;
    --secondary: #764ba2;
    --accent: #f093fb;
    --accent2: #f5576c;
    --bg-dark: #0f172a;
    --bg-card: rgba(255, 255, 255, 0.05);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --border: rgba(255, 255, 255, 0.1);
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

/* 动态背景 */
.bg-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.bg-animation::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background:
        radial-gradient(circle at 20% 80%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(118, 75, 162, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(240, 147, 251, 0.08) 0%, transparent 50%);
    animation: bgRotate 30s linear infinite;
}

@keyframes bgRotate {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 浮动粒子 */
.particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: rgba(102, 126, 234, 0.5);
    border-radius: 50%;
    animation: float 15s infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(100vh) rotate(0deg); opacity: 0; }
    10% { opacity: 1; }
    90% { opacity: 1; }
    100% { transform: translateY(-10vh) rotate(720deg); opacity: 0; }
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1rem 2rem;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    transition: all 0.3s ease;
}

.navbar.scrolled {
    padding: 0.5rem 2rem;
    background: rgba(15, 23, 42, 0.95);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 0;
    list-style: none;
    width: 100%;
    justify-content: space-evenly;
}

.nav-links li {
    flex: 1;
    text-align: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
    display: block;
    padding: 0.5rem 0;
}

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

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    transition: width 0.3s;
}

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

/* 按钮 */
.btn {
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.6);
}

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

.btn-secondary:hover {
    border-color: var(--primary);
    background: rgba(102, 126, 234, 0.1);
}

/* 通用区域标题 */
.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.section-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* 标签 */
.tag {
    padding: 0.25rem 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    border-radius: 20px;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* 页脚 */
.footer {
    padding: 3rem 2rem;
    text-align: center;
    border-top: 1px solid var(--border);
    color: var(--text-secondary);
}

.footer p {
    margin-bottom: 0.5rem;
}

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

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s;
}

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

/* 滚动动画 */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 响应式 */
@media (max-width: 768px) {
    .navbar {
        padding: 0.5rem 0 0 0;
    }

    .nav-container {
        flex-direction: column;
        align-items: stretch;
        gap: 0;
    }

    .logo {
        font-size: 1.2rem;
        padding: 0.5rem 1rem;
    }

    .nav-links {
        display: flex;
        gap: 0;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
        flex-wrap: nowrap;
        white-space: nowrap;
        max-width: 100%;
        width: 100%;
        justify-content: flex-start;
        border-top: 1px solid var(--border);
    }

    .nav-links::-webkit-scrollbar {
        display: none;
    }

    .nav-links li {
        flex: 1;
        text-align: center;
        min-width: 4rem;
    }

    .nav-links a {
        font-size: 0.85rem;
        padding: 0.6rem 0;
    }

    .section-header h2 {
        font-size: 1.8rem;
    }
}