/* 职途智航 · 课程中心 — 宽度自适应（管理系统） */

:root {
  /* —— Color tokens —— */
  --color-primary: #1b4eff; /* 主色-new */
  --color-theme: #1677ff; /* 主题色/主色 */
  --color-accent: #5f03ff;
  --text-primary: #303133; /* 文字/主色 */
  --text-secondary: #606266; /* 文字/辅色 */
  --text-muted: #909399;
  --text-on-primary: #ffffff;
  --bg-white: #ffffff; /* 背景色/White Fill */
  --bg-base: #f0f2f5; /* 背景色/Base Fill */
  --bg-page: #e8eef8;
  --grey-5: #d9d9d9; /* Grey-5 */
  --border-light: #e4e7ed;

  /* —— Elevation —— */
  --shadow-card:
    0 1px 2px rgba(32, 56, 100, 0.04),
    0 8px 24px rgba(32, 56, 100, 0.06);
  --shadow-card-hover:
    0 4px 12px rgba(27, 78, 255, 0.1),
    0 16px 36px rgba(27, 78, 255, 0.14);

  /* —— Motion —— */
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --duration: 180ms;

  /* —— Spacing / sizing (rem 基准 16px) —— */
  --space-1: 0.25rem; /* 4 */
  --space-2: 0.5rem; /* 8 */
  --space-3: 0.75rem; /* 12 */
  --space-4: 1rem; /* 16 */
  --space-5: 1.25rem; /* 20 */
  --space-6: 1.5rem; /* 24 */
  --space-8: 2rem; /* 32 */
  --radius-sm: 0.5rem; /* 8 */
  --radius-md: 0.75rem; /* 12 */
  --radius-lg: 1rem; /* 16 */
  --page-pad: clamp(1rem, 1.25vw, 1.5rem);
  --content-max: 75rem; /* 1200px */
  --top-h: 5rem; /* 80 */
  --card-min: 17.5rem; /* 280 */
  --float-safe-bottom: 10rem; /* 为航筑浮层预留 */

  /* —— Typography —— */
  --font-sans: "Source Han Sans SC", "Source Han Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  --text-xs: 0.75rem; /* 12 */
  --text-sm: 0.875rem; /* 14 */
  --text-md: 1rem; /* 16 */
  --text-lg: 1.125rem; /* 18 */
  --text-xl: 1.25rem; /* 20 */
  --leading-sm: 1.375rem; /* 22 */
  --leading-md: 1.5rem; /* 24 */

  /* —— Scrollbar —— */
  --scrollbar-size: 0.375rem; /* 6 */
  --scrollbar-track: transparent;
  --scrollbar-thumb: rgba(48, 49, 51, 0.18);
  --scrollbar-thumb-hover: rgba(27, 78, 255, 0.35);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  scrollbar-width: thin;
  scrollbar-color: var(--scrollbar-thumb) var(--scrollbar-track);
}

*::-webkit-scrollbar {
  width: var(--scrollbar-size);
  height: var(--scrollbar-size);
}

*::-webkit-scrollbar-track {
  background: var(--scrollbar-track);
}

*::-webkit-scrollbar-thumb {
  background-color: var(--scrollbar-thumb);
  border-radius: 999px;
  border: 2px solid transparent;
  background-clip: padding-box;
}

*::-webkit-scrollbar-thumb:hover {
  background-color: var(--scrollbar-thumb-hover);
}

*::-webkit-scrollbar-corner {
  background: transparent;
}

html {
  font-size: 100%; /* 1rem = 浏览器默认，便于 rem 适配 */
}

html,
body {
  width: 100%;
  min-height: 100%;
  background: var(--bg-page);
  font-family: var(--font-sans);
  color: var(--text-primary);
}

/* 标准前台：顶栏固定，Banner + 主体在视口内滚动 */
body:has(> .stage > .root > header.top) {
  height: 100dvh;
  overflow: hidden;
}

body:has(> .stage > .root > header.top) .stage {
  height: 100%;
  min-height: 0;
  overflow: hidden;
}

body:has(> .stage > .root > header.top) .root:not([data-name^="实训"]) {
  height: 100%;
  max-height: 100dvh;
  min-height: 0;
  overflow-x: hidden;
  overflow-y: auto;
  overscroll-behavior: contain;
  display: flex;
  flex-direction: column;
}

body:has(> .stage > .root > header.top) .root:not([data-name^="实训"]) > .top {
  position: sticky;
  top: 0;
  z-index: 30;
  flex: 0 0 auto;
}

body:has(> .stage > .root > header.top) .root:not([data-name^="实训"]) > .page-banner {
  flex: 0 0 auto;
}

body:has(> .stage > .root > header.top) .root:not([data-name^="实训"]) > .main {
  flex: 1 0 auto;
  min-height: 0;
  overflow: visible;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  border: 0;
  background: transparent;
  cursor: pointer;
}

/* 无障碍隐藏：仍可被读屏读取 */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}


.stage,
.root {
  width: 100%;
  min-height: 100vh;
}

.root {
  position: relative;
  display: flex;
  flex-direction: column;
  overflow: visible;
}

.bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

.bg__layer {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* —— 顶栏 —— */
.top {
  position: relative;
  z-index: 30;
  flex: 0 0 auto;
  width: 100%;
  min-height: var(--top-h);
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 12px var(--page-pad);
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: saturate(1.2) blur(14px);
  -webkit-backdrop-filter: saturate(1.2) blur(14px);
  border-bottom: 1px solid rgba(27, 78, 255, 0.06);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.65) inset;
}

.top__left {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: clamp(24px, 5vw, 100px);
  min-width: 0;
  flex: 1 1 auto;
}

.brand {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 4px;
  height: 59px;
  flex-shrink: 0;
  border-radius: 8px;
  transition: opacity var(--duration) var(--ease-out), transform var(--duration) var(--ease-out);
}

.brand:hover {
  opacity: 0.88;
}

.brand:active {
  transform: scale(0.98);
}

.brand:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 4px;
}

.brand__logo {
  width: 60px;
  height: 59px;
  object-fit: contain;
  display: block;
}

.brand__name {
  font-family: "Douyin Sans", "Source Han Sans SC", sans-serif;
  font-size: 24px;
  font-weight: 700;
  line-height: 24px;
  color: #3d3d3d;
  white-space: nowrap;
}

.nav {
  display: flex;
  flex-direction: row;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px 16px;
  min-width: 0;
}

.nav__item {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  height: 40px;
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 16px;
  line-height: 24px;
  font-weight: 400;
  color: var(--text-secondary);
  white-space: nowrap;
  transition:
    color var(--duration) var(--ease-out),
    background-color var(--duration) var(--ease-out),
    box-shadow var(--duration) var(--ease-out),
    transform var(--duration) var(--ease-out);
}

.nav__item:hover:not(.is-active) {
  color: var(--color-primary);
  background: rgba(27, 78, 255, 0.08);
}

.nav__item:active:not(.is-active) {
  transform: translateY(1px);
  background: rgba(27, 78, 255, 0.14);
}

.nav__item:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.nav__item.is-active {
  border-radius: 12px;
  background: linear-gradient(118deg, #1b4eff 0%, #3b6cff 62%, #5b8cff 100%);
  color: #ffffff;
  font-weight: 500;
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.22) inset,
    0 6px 14px rgba(27, 78, 255, 0.22);
}

.nav__item.is-active:hover {
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.28) inset,
    0 8px 18px rgba(27, 78, 255, 0.3);
}

.user-menu {
  position: relative;
  flex-shrink: 0;
  z-index: 20;
}

.user {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 8px;
  height: 40px;
  border-radius: 1000px;
  padding-right: 4px;
  cursor: pointer;
  transition: background-color var(--duration) var(--ease-out);
}

.user:hover,
.user-menu.is-open .user,
.user-menu:hover .user {
  background: rgba(27, 78, 255, 0.06);
}

.user:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.user__avatar {
  width: 40px;
  height: 40px;
  border-radius: 1000px;
  object-fit: cover;
  display: block;
  box-shadow: 0 0 0 1px rgba(27, 78, 255, 0.08);
  transition: box-shadow var(--duration) var(--ease-out), transform var(--duration) var(--ease-out);
}

.user:hover .user__avatar,
.user-menu.is-open .user__avatar,
.user-menu:hover .user__avatar {
  box-shadow: 0 0 0 2px rgba(27, 78, 255, 0.35);
  transform: scale(1.04);
}

.user__name {
  font-size: 14px;
  line-height: 22px;
  color: var(--text-secondary);
  white-space: nowrap;
}

/* 用户下拉 — 设计稿 51:7260，225×252 */
.user-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  width: 225px;
  min-height: 252px;
  padding: 24px;
  border-radius: 12px;
  background: #ffffff;
  box-shadow: 0 8px 24px rgba(32, 56, 100, 0.12);
  display: flex;
  flex-direction: column;
  gap: 24px;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(-4px);
  transition:
    opacity var(--duration) var(--ease-out),
    transform var(--duration) var(--ease-out),
    visibility var(--duration) var(--ease-out);
}

.user-dropdown::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: -12px;
  height: 12px;
}

.user-menu:hover .user-dropdown,
.user-menu.is-open .user-dropdown,
.user-menu:focus-within .user-dropdown {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

/* 关闭态用透明度/可见性，避免 display:none 打断过渡与读屏 */
.user-dropdown[aria-hidden="true"] {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(-0.25rem);
}

.user-dropdown__profile {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 8px;
  width: 177px;
  height: 60px;
}

.user-dropdown__avatar {
  width: 60px;
  height: 60px;
  border-radius: 1000px;
  object-fit: cover;
  display: block;
  flex-shrink: 0;
}

.user-dropdown__meta {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.user-dropdown__name {
  font-size: 16px;
  font-weight: 500;
  line-height: 24px;
  color: var(--text-secondary);
  white-space: nowrap;
}

.user-dropdown__role {
  font-size: 14px;
  line-height: 22px;
  /* token: 文字/次辅色 */
  color: #909399;
  white-space: nowrap;
}

.user-dropdown__actions {
  display: flex;
  flex-direction: column;
  gap: 24px;
  width: 166px;
}

.user-dropdown__item {
  display: flex;
  align-items: center;
  width: 166px;
  height: 48px;
  padding: 12px 16px;
  font-size: 16px;
  line-height: 24px;
  color: #3d3d3d;
  border-radius: 12px;
  transition: background-color var(--duration) var(--ease-out), color var(--duration) var(--ease-out);
}

.user-dropdown__item--admin {
  /* token: 背景色/Light Fill */
  background: #f5f7fa;
  justify-content: flex-start;
}

.user-dropdown__item--admin:hover {
  background: #ebeef5;
  color: var(--color-primary);
}

.user-dropdown__item--logout {
  justify-content: center;
  background: transparent;
  /* token: 边框/Lighter Border */
  border-top: 1px solid #ebeef5;
  border-radius: 0;
}

.user-dropdown__item--logout:hover {
  color: var(--color-primary);
  background: rgba(27, 78, 255, 0.04);
}

.user-dropdown__item:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* —— 页面 Banner / 内容区 —— */
.page-container {
  width: 100%;
  max-width: var(--content-max);
  margin-left: auto;
  margin-right: auto;
  box-sizing: border-box;
}

.page-banner {
  position: relative;
  z-index: 2;
  flex: 0 0 auto;
  width: 100%;
  min-height: clamp(7.5rem, 16vw, 10.75rem);
  overflow: hidden;
  background-color: #3b5bdb;
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.12) inset,
    0 8px 24px rgba(27, 46, 94, 0.12);
}

.page-banner__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 40%;
  pointer-events: none;
  user-select: none;
}

.page-banner--research .page-banner__bg {
  object-position: center center;
}

.page-banner::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(
      105deg,
      rgba(27, 78, 255, 0.28) 0%,
      rgba(27, 46, 94, 0.12) 48%,
      rgba(15, 23, 42, 0.18) 100%
    ),
    linear-gradient(
      180deg,
      rgba(15, 23, 42, 0.1) 0%,
      transparent 42%,
      rgba(15, 23, 42, 0.14) 100%
    );
  pointer-events: none;
}

.page-banner::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(
    90deg,
    transparent 0%,
    rgba(255, 255, 255, 0.28) 50%,
    transparent 100%
  );
  pointer-events: none;
}

.page-banner .page-banner__inner.page-container {
  max-width: none;
  width: 100%;
}

.page-banner__inner {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: clamp(7.5rem, 16vw, 10.75rem);
  padding: 1.5rem var(--page-pad) 1.625rem;
  text-align: center;
}

.page-banner__copy {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  max-width: 42rem;
  margin-inline: auto;
  text-align: center;
}

.page-banner__title {
  margin: 0;
  font-size: clamp(1.5rem, 2.9vw, 1.875rem);
  font-weight: 400;
  line-height: 1.28;
  color: #ffffff;
  letter-spacing: 0.08em;
  text-align: center;
  text-shadow: 0 2px 12px rgba(15, 23, 42, 0.28);
}

.page-banner__lead {
  margin: 0.625rem auto 0;
  max-width: 34rem;
  font-size: var(--text-sm);
  font-weight: 400;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.9);
  letter-spacing: 0.02em;
  text-align: center;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
  text-shadow: 0 1px 6px rgba(15, 23, 42, 0.18);
}

.page-banner--research {
  background-color: #2a7fd4;
}

.page-banner--research::before {
  background:
    linear-gradient(
      180deg,
      rgba(15, 23, 42, 0.06) 0%,
      transparent 45%,
      rgba(15, 23, 42, 0.1) 100%
    );
}

@media (max-width: 47.9375em) {
  .page-banner__inner {
    padding: 1.125rem var(--page-pad) 1.25rem;
  }

  .page-banner__lead {
    -webkit-line-clamp: 3;
  }
}

/* —— 主体 —— */
.main {
  position: relative;
  z-index: 2;
  flex: 1 1 auto;
  min-height: 0;
  width: 100%;
  background:
    radial-gradient(120% 80% at 50% 0%, rgba(27, 78, 255, 0.05) 0%, transparent 55%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.86) 0%, rgba(242, 246, 252, 0.92) 100%);
  overflow: visible;
  padding: calc(var(--page-pad) + 4px) var(--page-pad) var(--page-pad);
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.filters {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 16px;
  border-radius: 12px;
  background: #ffffff;
  flex-shrink: 0;
}

.filter-row {
  display: flex;
  flex-direction: row;
  align-items: flex-start;
  gap: 12px;
}

.filter-row__label {
  width: 56px;
  flex-shrink: 0;
  padding-top: 4px;
  font-size: 14px;
  font-weight: 500;
  line-height: 22px;
  color: var(--text-secondary);
}

.filter-row__chips {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  min-width: 0;
}

.chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 30px;
  padding: 4px 16px;
  border-radius: 100px;
  background: var(--bg-base);
  font-size: 14px;
  line-height: 22px;
  color: var(--text-secondary);
  white-space: nowrap;
  transition:
    color var(--duration) var(--ease-out),
    background-color var(--duration) var(--ease-out),
    box-shadow var(--duration) var(--ease-out),
    transform var(--duration) var(--ease-out);
}

.chip:hover:not(.is-active) {
  color: var(--color-primary);
  background: rgba(27, 78, 255, 0.1);
}

.chip:active:not(.is-active) {
  transform: scale(0.96);
}

.chip:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.chip.is-active {
  background: var(--color-primary);
  color: #ffffff;
  border-radius: 30px;
}

.chip.is-active:hover {
  background: #1646e6;
  box-shadow: 0 4px 12px rgba(27, 78, 255, 0.28);
}

/* —— 课程网格：随屏宽自动换列 —— */
.course-grid {
  width: 100%;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(var(--card-min), 1fr));
  gap: 22px;
  align-items: stretch;
  padding-bottom: 8px;
}

.course-grid__row {
  display: contents;
}

.course-card {
  width: 100%;
  min-width: 0;
  border-radius: 16px;
  background:
    linear-gradient(180deg, #ffffff 0%, #fbfcff 100%);
  border: 1px solid rgba(27, 78, 255, 0.07);
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  cursor: pointer;
  transform: translateY(0);
  transition:
    box-shadow 240ms var(--ease-out),
    transform 240ms var(--ease-out),
    border-color 240ms var(--ease-out);
}

.course-card:hover {
  border-color: rgba(27, 78, 255, 0.16);
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-5px);
  z-index: 1;
}

.course-card:active,
.course-card.is-pressed {
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(27, 78, 255, 0.12);
}

.course-card:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
}

/* —— 课程封面：科技蓝 Banner 风格 —— */
.course-card__cover {
  position: relative;
  width: 100%;
  aspect-ratio: 450 / 253;
  flex-shrink: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1rem 1.125rem;
  box-sizing: border-box;
  transition: transform 360ms var(--ease-out);
  background:
    radial-gradient(circle at 16% 24%, rgba(191, 219, 254, 0.5), transparent 42%),
    radial-gradient(circle at 86% 78%, rgba(96, 165, 250, 0.28), transparent 40%),
    radial-gradient(circle at 50% 120%, rgba(37, 99, 235, 0.45), transparent 52%),
    linear-gradient(118deg, #1b4eff 0%, #2563eb 48%, #3b82f6 100%);
}

.course-card__cover::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.14) 0%, transparent 38%, rgba(15, 23, 42, 0.14) 100%),
    linear-gradient(90deg, rgba(255, 255, 255, 0.05), transparent 40%, rgba(255, 255, 255, 0.08));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.22);
}

.course-card:nth-child(3n + 2) .course-card__cover {
  background:
    radial-gradient(circle at 20% 30%, rgba(186, 230, 253, 0.45), transparent 40%),
    radial-gradient(circle at 80% 70%, rgba(125, 211, 252, 0.28), transparent 42%),
    linear-gradient(122deg, #0f4cff 0%, #1d6bff 46%, #38bdf8 100%);
}

.course-card:nth-child(3n) .course-card__cover {
  background:
    radial-gradient(circle at 18% 26%, rgba(199, 210, 254, 0.42), transparent 40%),
    radial-gradient(circle at 84% 74%, rgba(147, 197, 253, 0.3), transparent 40%),
    linear-gradient(115deg, #1b4eff 0%, #3b6cff 50%, #60a5fa 100%);
}

/* 封面图卡片（共用结构） */
.course-card--cover-photo .course-card__cover {
  padding: 0;
}

.course-card--cover-photo--light .course-card__cover {
  background: #e6eef8;
}

.course-card--cover-photo--dark .course-card__cover {
  background: #1b4eff;
}

.course-card--cover-photo .course-card__cover-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center center;
  display: block;
  pointer-events: none;
  transition: transform 360ms var(--ease-out);
}

.course-card--cover-photo--light .course-card__cover::after {
  background:
    linear-gradient(
      180deg,
      rgba(255, 255, 255, 0.72) 0%,
      rgba(255, 255, 255, 0.28) 38%,
      rgba(255, 255, 255, 0.06) 62%,
      transparent 100%
    );
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.45);
}

.course-card--cover-photo--dark .course-card__cover::after {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.12) 0%, transparent 42%, rgba(15, 23, 42, 0.18) 100%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.18);
}

.course-card--cover-photo--light .course-card__cover-inner {
  z-index: 2;
  padding: 1rem 1.125rem 1.125rem;
  align-self: flex-start;
  margin-top: 0;
}

.course-card--cover-photo--dark .course-card__cover-inner {
  z-index: 2;
  padding: 1rem 1.125rem;
  align-self: center;
}

.course-card--cover-photo--light .course-card__cover-title {
  background: none;
  -webkit-background-clip: border-box;
  background-clip: border-box;
  color: #1a3a6d;
  filter: none;
  text-shadow: 0 1px 0 rgba(255, 255, 255, 0.9);
}

.course-card--cover-photo--light .course-card__cover-sub {
  color: #3d5a80;
  text-shadow: 0 1px 0 rgba(255, 255, 255, 0.75);
}

.course-card--cover-photo--light .course-card__cover-sub::before,
.course-card--cover-photo--light .course-card__cover-sub::after {
  color: #5b7a9e;
  opacity: 0.85;
}

.course-card--cover-photo--dark .course-card__cover-title {
  background: linear-gradient(180deg, #ffffff 0%, #eff6ff 58%, #dbeafe 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 2px 8px rgba(15, 23, 42, 0.28));
}

.course-card--cover-photo--dark .course-card__cover-sub {
  color: rgba(255, 255, 255, 0.9);
  text-shadow: 0 1px 4px rgba(15, 23, 42, 0.22);
}

.course-card--cover-photo--dark .course-card__cover-sub::before,
.course-card--cover-photo--dark .course-card__cover-sub::after {
  color: rgba(255, 255, 255, 0.75);
  opacity: 1;
}

.course-card--cover-photo:hover .course-card__cover {
  transform: none;
}

.course-card--cover-photo:hover .course-card__cover-bg {
  transform: scale(1.05);
}

.course-card__cover-deco {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.course-card__deco {
  position: absolute;
  display: block;
}

.course-card__deco--dots {
  left: 7%;
  top: 11%;
  width: 3.25rem;
  height: 2.25rem;
  opacity: 0.55;
  background-image: radial-gradient(circle, rgba(255, 255, 255, 0.8) 1.25px, transparent 1.25px);
  background-size: 7px 7px;
}

.course-card__deco--waves {
  left: 50%;
  top: 9%;
  width: 2.75rem;
  height: 0.875rem;
  transform: translateX(-50%);
  opacity: 0.85;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 44 14' fill='none'%3E%3Cpath d='M1 7c4-5 8 5 12 0s8 5 12 0 8 5 12 0' stroke='white' stroke-opacity='.65' stroke-width='1.5' stroke-linecap='round'/%3E%3Cpath d='M1 11c4-5 8 5 12 0s8 5 12 0 8 5 12 0' stroke='white' stroke-opacity='.45' stroke-width='1.5' stroke-linecap='round'/%3E%3C/svg%3E");
  background-size: contain;
  background-repeat: no-repeat;
}

.course-card__deco--rings {
  width: 2rem;
  height: 2rem;
  border: 2px solid rgba(255, 255, 255, 0.45);
  border-radius: 50%;
  box-shadow: 0 0 0 5px rgba(255, 255, 255, 0.12);
}

.course-card__deco--rings-tr {
  right: 7%;
  top: 10%;
}

.course-card__deco--rings-bl {
  left: 8%;
  bottom: 12%;
  width: 1.75rem;
  height: 1.75rem;
  background: repeating-linear-gradient(
    -45deg,
    transparent,
    transparent 3px,
    rgba(255, 255, 255, 0.35) 3px,
    rgba(255, 255, 255, 0.35) 4px
  );
  mask: radial-gradient(circle, transparent 52%, #000 53%);
  border: none;
  box-shadow: none;
}

.course-card__deco--cross {
  right: 8%;
  bottom: 11%;
  width: 2.5rem;
  height: 2rem;
  opacity: 0.55;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 40 32' fill='none'%3E%3Cg stroke='white' stroke-width='1.2' stroke-opacity='.8'%3E%3Cpath d='M4 4h8v8H4zM16 4h8v8h-8zM28 4h8v8h-8zM4 16h8v8H4zM16 16h8v8h-8zM28 16h8v8h-8z'/%3E%3Cpath d='M8 8v0M20 8v0M32 8v0M8 20v0M20 20v0M32 20v0' stroke-width='2'/%3E%3C/g%3E%3C/svg%3E");
  background-size: contain;
  background-repeat: no-repeat;
}

.course-card__deco--blob {
  border-radius: 50%;
  filter: blur(18px);
  background: rgba(191, 219, 254, 0.55);
}

.course-card__deco--blob-a {
  width: 38%;
  aspect-ratio: 1;
  left: -10%;
  bottom: -25%;
}

.course-card__deco--blob-b {
  width: 32%;
  aspect-ratio: 1;
  right: -8%;
  top: -20%;
  background: rgba(165, 180, 252, 0.45);
}

.course-card__cover-inner {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 94%;
  text-align: center;
}

.course-card__cover-title {
  margin: 0;
  font-size: clamp(0.9375rem, 2.5vw, 1.25rem);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: 0.03em;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
  background: linear-gradient(180deg, #ffffff 0%, #eff6ff 58%, #dbeafe 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 2px 8px rgba(15, 23, 42, 0.2));
}

.course-card__cover-sub {
  margin: 0.5rem 0 0;
  padding: 0 0.25rem;
  font-size: clamp(0.6875rem, 1.8vw, 0.8125rem);
  font-weight: 400;
  line-height: 1.5;
  color: rgba(255, 255, 255, 0.88);
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
  text-shadow: 0 1px 4px rgba(15, 23, 42, 0.16);
}

.course-card__cover-sub::before {
  content: "\201C";
  margin-right: 0.1em;
  opacity: 0.85;
}

.course-card__cover-sub::after {
  content: "\201D";
  margin-left: 0.1em;
  opacity: 0.85;
}

.course-card__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 320ms var(--ease-out);
}

.course-card:hover .course-card__cover {
  transform: scale(1.035);
}

.course-card:hover .course-card__cover img {
  transform: scale(1.05);
}

.course-card__body {
  position: relative;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
  padding: 16px 16px 18px;
  flex: 1 1 auto;
}

.course-card__body::before {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  top: 0;
  height: 1px;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(27, 78, 255, 0.1),
    transparent
  );
  pointer-events: none;
}

.course-card__meta {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 100%;
  min-width: 0;
  flex: 1 1 auto;
}

.course-card__title {
  margin: 0;
  width: 100%;
  font-size: var(--text-lg);
  font-weight: 600;
  line-height: 1.45;
  letter-spacing: 0.01em;
  color: #1f2937;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
  transition: color 220ms var(--ease-out);
}

.course-card:hover .course-card__title {
  color: var(--color-primary);
}

.course-card__desc {
  font-size: var(--text-sm);
  line-height: var(--leading-sm);
  color: var(--text-muted);
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
  margin: 0;
}

.course-card__tags {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 6px;
  width: 100%;
  flex-wrap: wrap;
}

.course-card__tag {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 1.625rem;
  padding: 0 10px;
  border-radius: 999px;
  font-size: var(--text-xs);
  line-height: 1.25rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: #2f5bff;
  background: linear-gradient(180deg, rgba(27, 78, 255, 0.08) 0%, rgba(27, 78, 255, 0.05) 100%);
  border: 1px solid rgba(27, 78, 255, 0.12);
  white-space: nowrap;
  transition:
    background-color 180ms var(--ease-out),
    border-color 180ms var(--ease-out),
    color 180ms var(--ease-out);
}

.course-card:hover .course-card__tag {
  color: var(--color-primary);
  background: rgba(27, 78, 255, 0.1);
  border-color: rgba(27, 78, 255, 0.18);
}

.course-card__tag:nth-child(2) {
  color: #2563eb;
  background: linear-gradient(180deg, rgba(37, 99, 235, 0.08) 0%, rgba(37, 99, 235, 0.04) 100%);
  border-color: rgba(37, 99, 235, 0.12);
}

.course-card__tag:nth-child(3) {
  color: #475569;
  background: linear-gradient(180deg, #f8fafc 0%, #f1f5f9 100%);
  border-color: rgba(148, 163, 184, 0.28);
}

.course-card__divider {
  width: 1px;
  height: 12px;
  background: var(--grey-5);
  flex-shrink: 0;
}

.course-card__tools {
  display: flex;
  flex-direction: row;
  justify-content: flex-end;
  align-items: center;
  width: 100%;
  margin-top: auto;
}

.course-card__tool-list {
  display: flex;
  flex-direction: row;
  gap: 8px;
  height: 32px;
}

.course-card__tool {
  width: 32px;
  height: 32px;
  border-radius: 20px;
  object-fit: cover;
  display: block;
  transition: transform var(--duration) var(--ease-out), box-shadow var(--duration) var(--ease-out);
}

.course-card:hover .course-card__tool {
  box-shadow: 0 2px 8px rgba(32, 56, 100, 0.16);
}

.course-card:hover .course-card__tool:nth-child(1) {
  transform: translateY(-2px);
}

.course-card:hover .course-card__tool:nth-child(2) {
  transform: translateY(-4px);
  transition-delay: 40ms;
}

.course-card:hover .course-card__tool:nth-child(3) {
  transform: translateY(-2px);
  transition-delay: 80ms;
}

/* 断点：大屏偏宽卡片；小屏用 rem/token 收紧 */
@media (min-width: 100em) {
  /* 1600px */
  :root {
    --card-min: 22.5rem;
  }
}

@media (max-width: 90em) {
  /* 1440px：小分辨率笔记本 */
  :root {
    --page-pad: 1rem;
    --card-min: 15rem;
    --top-h: 4rem;
    --float-safe-bottom: 9.5rem;
  }

  .top {
    gap: var(--space-3);
    padding-block: var(--space-2);
    min-height: var(--top-h);
  }

  .top__left {
    gap: var(--space-4) var(--space-5);
  }

  .brand {
    height: 3rem;
  }

  .brand__logo {
    width: 3rem;
    height: 3rem;
  }

  .brand__name {
    font-size: var(--text-xl);
    line-height: var(--leading-md);
  }

  .nav {
    gap: var(--space-1) var(--space-2);
  }

  .nav__item {
    height: 2.25rem;
    padding: 0.375rem 0.625rem;
    font-size: var(--text-sm);
    line-height: var(--leading-sm);
  }

  .nav__item.is-active {
    border-radius: var(--radius-sm);
  }

  .main {
    gap: var(--space-4);
    padding-bottom: calc(var(--page-pad) + var(--float-safe-bottom));
  }
}

@media (max-width: 85.375em) {
  /* 1366px：顶栏导航横向滚动，避免挤压换行 */
  .top__left {
    flex-wrap: nowrap;
    min-width: 0;
  }

  .nav {
    flex: 1 1 auto;
    flex-wrap: nowrap;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
    max-width: 100%;
    padding-bottom: 0.125rem;
  }

  .nav__item {
    flex: 0 0 auto;
  }

  .user__name {
    /* 视觉隐藏，读屏仍可读到用户名 */
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
  }
}

@media (max-width: 74.9375em) {
  /* 1199px */
  :root {
    --card-min: 16.25rem;
    --top-h: auto;
    --float-safe-bottom: 8.75rem;
  }

  .top {
    align-items: flex-start;
    padding-block: var(--space-3);
  }

  .top__left {
    flex-wrap: wrap;
    gap: var(--space-3) var(--space-6);
  }

  .nav {
    width: 100%;
    flex-wrap: wrap;
    overflow: visible;
  }

  .main {
    padding-bottom: calc(var(--page-pad) + var(--float-safe-bottom));
  }
}

@media (max-width: 47.9375em) {
  /* 767px */
  :root {
    --card-min: 100%;
    --page-pad: 0.75rem;
    --float-safe-bottom: 7.5rem;
  }

  .brand__name {
    font-size: var(--text-lg);
  }

  .nav__item {
    height: 2.125rem;
    padding: 0.375rem 0.625rem;
    font-size: 0.8125rem;
  }

  .filter-row {
    flex-direction: column;
    gap: var(--space-2);
  }

  .filter-row__label {
    padding-top: 0;
  }

  .course-grid {
    gap: var(--space-4);
  }

  .main {
    padding-bottom: calc(var(--page-pad) + var(--float-safe-bottom));
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms;
    animation-duration: 0.01ms;
    scroll-behavior: auto;
  }

  .course-card:hover,
  .course-card:active,
  .course-card.is-pressed {
    transform: none;
  }

  .course-card:hover .course-card__cover,
  .course-card:hover .course-card__cover img,
  .course-card:hover .course-card__tool {
    transform: none;
  }
}