/* 容器类 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* 间距工具类 */
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* 弹性布局工具类 */
.d-flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.justify-center { justify-content: center; }
.align-center { align-items: center; }

/* 文本工具类 */
.text-center { text-align: center; }
.text-primary { color: #3498db; }
.text-secondary { color: #2ecc71; }
.text-dark { color: #333; }
.text-light { color: #f4f4f4; }