.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }

.w-full { width: 100%; }
.h-full { height: 100%; }

// 外边距
.mt-sm { margin-top: $space-sm; }
.mt-md { margin-top: $space-md; }
.mb-sm { margin-bottom: $space-sm; }

// 内边距
.p-sm { padding: $space-sm; }
.p-md { padding: $space-md; }