:root {
    --primary-color: #4361ee;
    --secondary-color: #3f37c9;
    --accent-color: #4895ef;
    --success-color: #4cc9f0;
    --danger-color: #f72585;
    --warning-color: #f8961e;
    --light-color: #f8f9fa;
    --dark-color: #212529;
    --gray-color: #6c757d;
    
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --border-radius: 0.5rem;
    --box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--dark-color);
    background-color: #f5f7fa;
    -webkit-font-smoothing: antialiased;
}

/* 容器 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* 排版 */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
}

p {
    margin-bottom: 1rem;
}

/* 按钮 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    white-space: nowrap;
}

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

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

/* 卡片 */
.card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 2rem;
    margin-bottom: 2rem;
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

/* 表单 */
.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 1px solid #e2e8f0;
    border-radius: var(--border-radius);
    transition: var(--transition);
    background-color: #fff;
}

.form-control:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.15);
    outline: none;
}

/* 导航栏 */
.navbar {
    background-color: var(--dark-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    text-decoration: none;
}

.nav-link {
    color: rgba(255, 255, 255, 0.8);
    margin: 0 1rem;
    font-weight: 500;
    transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
    color: white;
}

/* 页脚 */
.footer {
    background-color: var(--dark-color);
    color: white;
    padding: 3rem 0;
    margin-top: 3rem;
}

.footer a {
    color: rgba(255, 255, 255, 0.8);
    transition: var(--transition);
}

.footer a:hover {
    color: white;
}

/* 表格 */
.table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 2rem;
    background-color: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--box-shadow);
}

.table th, .table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid #e2e8f0;
}

.table th {
    background-color: #f8fafc;
    font-weight: 600;
    color: var(--dark-color);
}

.table tr:hover {
    background-color: #f8fafc;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    
    .card {
        padding: 1.5rem;
    }
    
    .btn {
        padding: 0.65rem 1.25rem;
    }
}