/**
 * 小梅英语训练营 - 公共工具类
 * 供学生端和教师端共用
 * 命名约定：简写 + 数值，如 .mt-8、.gap-12
 */

/* ===== Display ===== */
.d-flex    { display: flex; }
.d-none    { display: none; }
.d-block   { display: block; }
.d-inline  { display: inline; }
.d-inline-block { display: inline-block; }

/* ===== Flex 布局 ===== */
.flex-row       { display: flex; align-items: center; gap: 12px; }
.flex-column    { display: flex; flex-direction: column; }
.flex-wrap      { display: flex; flex-wrap: wrap; gap: 10px; }
.flex-between   { display: flex; align-items: center; justify-content: space-between; }
.flex-center    { display: flex; align-items: center; justify-content: center; }
.flex-1         { flex: 1; }
.flex-shrink-0  { flex-shrink: 0; }

/* ===== Gap ===== */
.gap-4  { gap: 4px; }
.gap-6  { gap: 6px; }
.gap-8  { gap: 8px; }
.gap-10 { gap: 10px; }
.gap-12 { gap: 12px; }
.gap-16 { gap: 16px; }

/* ===== Margin ===== */
.mt-4  { margin-top: 4px; }
.mt-8  { margin-top: 8px; }
.mt-12 { margin-top: 12px; }
.mt-16 { margin-top: 16px; }
.mt-20 { margin-top: 20px; }
.mt-24 { margin-top: 24px; }

.mb-4  { margin-bottom: 4px; }
.mb-8  { margin-bottom: 8px; }
.mb-12 { margin-bottom: 12px; }
.mb-16 { margin-bottom: 16px; }
.mb-20 { margin-bottom: 20px; }

.ml-auto { margin-left: auto; }
.mr-auto { margin-right: auto; }
.mx-auto { margin-left: auto; margin-right: auto; }

/* ===== Padding ===== */
.p-4  { padding: 4px; }
.p-8  { padding: 8px; }
.p-12 { padding: 12px; }
.p-16 { padding: 16px; }
.p-20 { padding: 20px; }

.px-8  { padding-left: 8px; padding-right: 8px; }
.px-12 { padding-left: 12px; padding-right: 12px; }
.px-16 { padding-left: 16px; padding-right: 16px; }
.px-20 { padding-left: 20px; padding-right: 20px; }

.py-4  { padding-top: 4px; padding-bottom: 4px; }
.py-8  { padding-top: 8px; padding-bottom: 8px; }
.py-12 { padding-top: 12px; padding-bottom: 12px; }

/* ===== Text ===== */
.text-left     { text-align: left; }
.text-center   { text-align: center; }
.text-right    { text-align: right; }
.text-nowrap   { white-space: nowrap; }
.text-ellipsis { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.text-xs  { font-size: var(--font-size-xs, 11px); }
.text-sm  { font-size: var(--font-size-sm, 12px); }
.text-md  { font-size: var(--font-size-md, 14px); }
.text-lg  { font-size: var(--font-size-lg, 18px); }
.text-xl  { font-size: 22px; }

.font-bold   { font-weight: 600; }
.font-normal { font-weight: 400; }
.font-mono   { font-family: monospace; }

/* ===== 颜色（配合 CSS 变量） ===== */
.text-primary   { color: var(--primary, #667eea); }
.text-success   { color: var(--success, #52c41a); }
.text-danger    { color: var(--danger, #ff4d4f); }
.text-warning   { color: var(--warning, #faad14); }
.text-secondary { color: var(--text-secondary, #888); }
.text-light     { color: var(--text-light, #999); }
.text-white     { color: #fff; }
.text-muted     { color: #bbb; }

/* ===== 宽度 ===== */
.w-full  { width: 100%; }
.w-auto  { width: auto; }
.h-full  { height: 100%; }

/* ===== 圆角 ===== */
.rounded-sm  { border-radius: 6px; }
.rounded     { border-radius: 8px; }
.rounded-md  { border-radius: 10px; }
.rounded-lg  { border-radius: 12px; }
.rounded-full { border-radius: 50%; }

/* ===== 阴影 ===== */
.shadow-sm { box-shadow: 0 1px 4px rgba(0,0,0,0.06); }
.shadow    { box-shadow: 0 2px 12px rgba(0,0,0,0.08); }
.shadow-lg { box-shadow: 0 4px 24px rgba(0,0,0,0.12); }

/* ===== 其他 ===== */
.cursor-pointer { cursor: pointer; }
.overflow-hidden { overflow: hidden; }
.overflow-auto   { overflow: auto; }
.position-relative { position: relative; }
.position-absolute { position: absolute; }