/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft Yahei", PingFang SC, sans-serif;
}

/* 页面背景 */
body {
    min-height: 100vh;
    background: linear-gradient(135deg, #e0f0ff 0%, #f0e8ff 100%);
    background-attachment: fixed;
}

/* 主容器 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
}

/* 头部区域 */
.header {
    text-align: center;
    margin-bottom: 50px;
    animation: fadeIn 1s ease-in-out;
}

.header h1 {
    font-size: 2.5rem;
    color: #2c5282;
    margin-bottom: 12px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header p {
    font-size: 1.1rem;
    color: #4a5568;
    letter-spacing: 1px;
}

/* 导航卡片网格布局 */
.nav-wrap {
    display: grid;
    /* 自适应列数 */
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

/* 导航卡片核心样式 + 灵动动效 */
.nav-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 35px 20px;
    background: #ffffff;
    border-radius: 16px;
    text-decoration: none;
    box-shadow: 0 4px 12px rgba(44, 82, 130, 0.15);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    animation: slideUp 0.6s ease forwards;
    opacity: 0;
}

/* 卡片依次延迟出现 */
.nav-card:nth-child(1) { animation-delay: 0.1s; }
.nav-card:nth-child(2) { animation-delay: 0.2s; }
.nav-card:nth-child(3) { animation-delay: 0.3s; }
.nav-card:nth-child(4) { animation-delay: 0.4s; }
.nav-card:nth-child(5) { animation-delay: 0.5s; }
.nav-card:nth-child(6) { animation-delay: 0.6s; }
.nav-card:nth-child(7) { animation-delay: 0.7s; }

/* 卡片悬浮灵动效果 */
.nav-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 12px 28px rgba(44, 82, 130, 0.25);
    background: linear-gradient(135deg, #f7faff, #f5f0ff);
}

/* 图标样式 */
.card-icon {
    font-size: 3rem;
    margin-bottom: 16px;
    line-height: 1;
}

/* 文字样式 */
.card-text {
    font-size: 1.15rem;
    color: #2d3748;
    font-weight: 500;
    text-align: center;
}

/* 页脚 */
.footer {
    text-align: center;
    margin-top: 60px;
    color: #718096;
    font-size: 0.95rem;
}

/* 动画：淡入 */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

/* 移动端适配 */
@media (max-width: 768px) {
    .header h1 {
        font-size: 2rem;
    }
    .nav-card {
        padding: 28px 15px;
    }
    .card-icon {
        font-size: 2.5rem;
    }
}