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

:root {
    --primary-color: #3b82f6;
    --secondary-color: #10b981;
    --dark-color: #1f2937;
    --light-color: #f9fafb;
    --text-color: #374151;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #ffffff;
}

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

/* ===== 导航栏 ===== */
.navbar {
    background-color: #ffffff;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.logo h1 {
    font-size: 1.8rem;
    color: var(--primary-color);
    font-weight: 700;
}

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

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

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

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    right: 0;
    height: 2px;
    background-color: var(--primary-color);
}

/* ===== 公告区域 ===== */
.announcement {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    padding: 1.5rem 0;
    border-bottom: 2px solid #fcd34d;
}

.announcement-content {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.announcement-icon {
    font-size: 1.8rem;
    flex-shrink: 0;
}

.announcement h3 {
    color: var(--dark-color);
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.announcement p {
    color: #78350f;
    font-size: 0.95rem;
}

/* ===== 英雄区域 ===== */
.hero {
    padding: 80px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

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

.hero-content h2 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: #2563eb;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
    background-color: transparent;
    color: white;
    border-color: white;
}

.btn-secondary:hover {
    background-color: white;
    color: var(--primary-color);
    transform: translateY(-2px);
}

.hero-image {
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-shape {
    width: 300px;
    height: 300px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    animation: float 3s ease-in-out infinite;
}

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

/* ===== 功能特性 ===== */
.features {
    padding: 80px 0;
    background-color: var(--light-color);
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    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: 0.75rem;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.75rem;
    color: var(--dark-color);
}

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

/* ===== 快速链接 ===== */
.quick-links {
    padding: 80px 0;
}

.quick-links h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--dark-color);
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.link-card {
    background: white;
    padding: 2rem;
    border-radius: 0.75rem;
    border: 2px solid var(--border-color);
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
    cursor: pointer;
}

.link-card:hover {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.1);
    transform: translateX(5px);
}

.link-card h4 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

.link-card p {
    color: var(--text-color);
    font-size: 0.95rem;
}

/* ===== 页脚 ===== */
.footer {
    background-color: var(--dark-color);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

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

.footer-links a {
    color: #d1d5db;
    text-decoration: none;
    transition: color 0.3s ease;
}

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

/* ===== 响应式设计 ===== */
@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-links {
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: center;
    }

    .hero .container {
        grid-template-columns: 1fr;
        padding: 40px 0;
    }

    .hero-content h2 {
        font-size: 2.5rem;
    }

    .hero-content p {
        font-size: 1.1rem;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

    .hero-shape {
        display: none;
    }

    .features h2,
    .quick-links h2 {
        font-size: 2rem;
    }

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