:root {
  --页面背景: #f5f6fa;
  --卡片背景: #ffffff;
  --主文本: #1f2937;
  --次文本: #6b7280;
  --主题色: #3f8cff;
  --边框色: #e5e7eb;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--页面背景);
  color: var(--主文本);
  font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

.app-shell {
  max-width: 960px;
  margin: 0 auto;
  min-height: 100vh;
  background: var(--页面背景);
}

.app-topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
  padding: 0 12px;
  border-bottom: 1px solid var(--边框色);
  background: #ffffff;
}

.app-top-left,
.app-top-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.app-logo {
  width: 100px;
  height: 24px;
  object-fit: contain;
}

.app-back {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 52px;
  height: 30px;
  padding: 0 10px;
  border: 1px solid var(--边框色);
  border-radius: 15px;
  background: #fff;
  color: var(--次文本);
  font-size: 13px;
}

.app-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 66px;
  height: 30px;
  padding: 0 10px;
  border-radius: 15px;
  border: 0;
  background: var(--主题色);
  color: #fff;
  font-size: 13px;
  cursor: pointer;
}

.app-main {
  padding: 12px;
}

.app-card {
  background: var(--卡片背景);
  border: 1px solid var(--边框色);
  border-radius: 12px;
  padding: 12px;
  margin-bottom: 12px;
}

.app-title {
  margin: 0 0 8px;
  font-size: 18px;
  line-height: 1.4;
}

.app-sub {
  margin: 0;
  color: var(--次文本);
  font-size: 13px;
}

.app-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.app-item {
  display: block;
  background: var(--卡片背景);
  border: 1px solid var(--边框色);
  border-radius: 10px;
  padding: 10px;
}

.app-item-head {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.app-avatar {
  width: 36px;
  height: 36px;
  border-radius: 18px;
  object-fit: cover;
  background: #f3f4f6;
}

.app-item-title {
  margin: 0;
  font-size: 16px;
  line-height: 1.4;
}

.app-item-text {
  margin: 8px 0 0;
  color: var(--次文本);
  line-height: 1.5;
  word-break: break-word;
}

.app-image-grid {
  margin-top: 8px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 6px;
}

.app-image-grid img {
  width: 100%;
  aspect-ratio: 1.8;
  object-fit: cover;
  border-radius: 8px;
  background: #f3f4f6;
}

.app-item-meta {
  margin-top: 8px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  color: var(--次文本);
  font-size: 12px;
}

.app-pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin: 14px 0 4px;
}

.app-page-link {
  display: inline-flex;
  min-width: 34px;
  height: 30px;
  padding: 0 10px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--边框色);
  border-radius: 15px;
  background: #fff;
  font-size: 13px;
  color: #374151;
}

.app-page-current {
  background: var(--主题色);
  color: #fff;
  border-color: var(--主题色);
}

.app-error-card {
  background: #fff;
  border: 1px solid var(--边框色);
  border-radius: 12px;
  padding: 20px 14px;
  text-align: center;
}

.app-error-image {
  width: min(260px, 70vw);
  height: auto;
  margin-bottom: 12px;
}

.app-error-card h2 {
  margin: 0;
  font-size: 18px;
}

.app-error-card p {
  margin: 10px 0 0;
  color: var(--次文本);
}

.app-rich {
  line-height: 1.8;
  word-break: break-word;
}

.app-rich img {
  max-width: 100%;
  border-radius: 8px;
  background: #f3f4f6;
}

.app-rich iframe,
.app-rich video {
  max-width: 100%;
}

.app-tabs {
  display: flex;
  gap: 8px;
}

.app-tab {
  display: inline-flex;
  height: 30px;
  padding: 0 12px;
  align-items: center;
  justify-content: center;
  border-radius: 15px;
  border: 1px solid var(--边框色);
  background: #fff;
  font-size: 13px;
}

.app-tab-active {
  background: var(--主题色);
  color: #fff;
  border-color: var(--主题色);
}

.app-search-box {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--边框色);
  border-radius: 10px;
  background: #fff;
  font-size: 14px;
  outline: none;
}

.app-search-box:focus {
  border-color: var(--主题色);
}

@media (max-width: 640px) {
  .app-main {
    padding: 10px;
  }

  .app-title {
    font-size: 16px;
  }
}