/* ============================================================
   vtbae 笔记 — 小红书风设计系统
   品牌红 #FF2442 / 瀑布流笔记卡 / 3:4 鲜亮封面 / 大 emoji
   ============================================================ */

:root {
  /* 品牌 */
  --red: #FF2442;
  --red-deep: #E01F3B;
  --red-soft: #FFE4E9;
  --red-tint: #FFF5F7;

  /* 中性 */
  --bg: #F6F6F6;
  --card: #FFFFFF;
  --line: #EFEFEF;
  --line-strong: #E5E5E5;
  --text: #333333;
  --text-2: #666666;
  --text-3: #999999;

  /* 形状 */
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
  --shadow-hover: 0 6px 20px rgba(0, 0, 0, 0.10);

  --wrap: 1080px;
  --font: "PingFang SC", "HarmonyOS Sans SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

/* 品牌红选区 + 细滚动条（桌面质感） */
::selection { background: rgba(255, 36, 66, 0.16); color: inherit; }
::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-thumb { background: #D9D9D9; border-radius: 999px; border: 2px solid transparent; background-clip: content-box; }
::-webkit-scrollbar-thumb:hover { background: #C4C4C4; background-clip: content-box; border: 2px solid transparent; }
::-webkit-scrollbar-track { background: transparent; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.75;
}

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

img, svg { display: block; max-width: 100%; }

/* ============================================================
   顶栏
   ============================================================ */

/* ============================================================
   首页 Hero（热门笔记大卡）
   ============================================================ */
.hero-kicker {
  display: inline-block;
  background: var(--red);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 6px;
  margin-bottom: 14px;
  letter-spacing: 0.05em;
}

.hero-cover {
  aspect-ratio: 3 / 4;
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 38px 20px 48px;
  box-shadow: var(--shadow);
}
.hero-cover-link { display: block; }
.hero-cover .temoji {
  position: absolute;
  left: 18px;
  bottom: 16px;
  top: auto;
  transform: none;
  font-size: 46px;
  line-height: 1;
}

/* ============================================================
   笔记封面通用元件（三点 / 日期 / 居中标题 / 大 emoji）
   ============================================================ */
.ctitle {
  font-size: var(--ct, 24px);   /* 每篇封面按最长一行自适应（生成时写入 --ct） */
  font-weight: 800;
  line-height: 1.44;
  color: var(--gink, #1F1F1F);  /* 标题色随封面底色变化（g-* 渐变里定义 --gink） */
  letter-spacing: 0.01em;
  word-break: break-word;
  margin: 0;                    /* 卡片封面用 h3 承载标题，需清掉默认外边距 */
}

/* 卡片封面标题：瀑布流列宽随视口变化，不能预算断行（会二次折行留下孤立单字），
   改由浏览器均衡折行；字号跟着卡片宽度走（container query），
   这样两列时字更大、四列时自动收小，始终是 2 行左右。 */
.note .thumb {
  container-type: inline-size;
}
.note .thumb .ctitle {
  font-size: clamp(15px, 7.8cqw, 22px);
  line-height: 1.5;
  text-wrap: balance;
}
.cdots {
  position: absolute;
  top: 15px;
  left: 15px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  color: var(--gmeta, rgba(0, 0, 0, 0.26));
  background: currentColor;
  box-shadow: 9px 0 0 currentColor, 18px 0 0 currentColor;
}
.cdate {
  position: absolute;
  top: 13px;
  right: 15px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--gmeta, rgba(0, 0, 0, 0.4));
}

/* ============================================================
   封面底色（低饱和奶油色系，小红书笔记封面调）
   每种底色配套一组文字色：--gink 标题 / --gmeta 日期与三点
   ============================================================ */
.g-rose {
  --gink: #B4446A; --gmeta: rgba(180, 68, 106, 0.5);
  background: linear-gradient(165deg, #FFF0F4 0%, #FFE0E9 55%, #FFCEDC 100%);
}
.g-butter {
  --gink: #8F6B14; --gmeta: rgba(143, 107, 20, 0.5);
  background: linear-gradient(165deg, #FFFBE6 0%, #FDF3C4 55%, #F9E9A0 100%);
}
.g-peach {
  --gink: #B25B33; --gmeta: rgba(178, 91, 51, 0.5);
  background: linear-gradient(165deg, #FFF4EB 0%, #FFE6D2 55%, #FBD7B7 100%);
}
.g-lilac {
  --gink: #5D50B8; --gmeta: rgba(93, 80, 184, 0.45);
  background: linear-gradient(165deg, #F1F0FF 0%, #E3E0FF 55%, #D3CEFF 100%);
}
.g-sky {
  --gink: #38699F; --gmeta: rgba(56, 105, 159, 0.5);
  background: linear-gradient(165deg, #EDF5FF 0%, #DCEBFE 55%, #C7DDFC 100%);
}
.g-mint {
  --gink: #2F7D58; --gmeta: rgba(47, 125, 88, 0.5);
  background: linear-gradient(165deg, #EDF8F0 0%, #DCF0E3 55%, #C8E7D3 100%);
}

/* ============================================================
   区块标题
   ============================================================ */
.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin: 34px 0 16px;
}
.section-head h2 {
  font-size: 20px;
  font-weight: 800;
}
.section-head .more {
  font-size: 13px;
  color: var(--text-3);
}
.section-head .more:hover { color: var(--red); }

/* ============================================================
   笔记瀑布流卡片
   ============================================================ */

/* ============================================================
   编辑精选（列表行）
   ============================================================ */

/* ============================================================
   话题广场（原 Newsletter）
   ============================================================ */

/* ============================================================
   二级栏目页
   ============================================================ */

.cat-filter-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 22px 0 16px;
  flex-wrap: wrap;
}
.cat-filter-bar .flabel { font-size: 13px; color: var(--text-3); }
.cat-filter-bar .chip {
  font-size: 13px;
  padding: 6px 16px;
  border-radius: 999px;
  background: var(--card);
  border: 1px solid var(--line-strong);
  color: var(--text-2);
  cursor: pointer;
  transition: all 0.15s;
}
.cat-filter-bar .chip:hover { border-color: var(--red); color: var(--red); }
.cat-filter-bar .chip.active {
  background: var(--red);
  border-color: var(--red);
  color: #fff;
  font-weight: 600;
}

.cat-pager {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  margin: 28px 0 44px;
  flex-wrap: wrap;
}
.cat-pager a, .cat-pager span {
  min-width: 36px;
  height: 36px;
  padding: 0 12px;
  border-radius: var(--radius-sm);
  background: var(--card);
  border: 1px solid var(--line-strong);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  color: var(--text-2);
}
.cat-pager a:hover { border-color: var(--red); color: var(--red); }
.cat-pager a.active, .cat-pager a[aria-current="page"] {
  background: var(--red);
  border-color: var(--red);
  color: #fff;
  font-weight: 700;
}
.cat-pager .disabled { color: var(--text-3); opacity: 0.5; cursor: default; }
.cat-pager .info { border: 0; background: transparent; color: var(--text-3); font-size: 13px; }

/* ============================================================
   文章详情页
   ============================================================ */
.article-head { max-width: 720px; margin: 24px auto 0; padding: 0 4px; }
.article-head .kicker {
  display: inline-block;
  background: var(--red);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 6px;
  margin-bottom: 12px;
}
.article-head h1 {
  font-size: 26px;
  font-weight: 800;
  line-height: 1.4;
  margin-bottom: 10px;
}
.article-head .dek { color: var(--text-2); font-size: 15px; margin-bottom: 12px; }
.article-head .byline {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-3);
  font-size: 13px;
}
.article-head .byline .avatar {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--red);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

.article-cover {
  max-width: 460px;
  margin: 20px auto;
}
.article-cover .cover-inner {
  aspect-ratio: 3 / 4;
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 46px 26px 56px;
  box-shadow: var(--shadow);
}
.article-cover .cover-inner .temoji {
  position: absolute;
  left: 22px;
  bottom: 20px;
  top: auto;
  transform: none;
  font-size: 54px;
  line-height: 1;
}

.article-body { max-width: 720px; margin: 0 auto; padding: 0 4px 40px; }

.article-body .lead {
  font-size: 16px;
  color: var(--text-2);
  background: var(--red-tint);
  border-left: 3px solid var(--red);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 14px 16px;
  margin-bottom: 24px;
  line-height: 1.8;
}

.article-body h2 {
  font-size: 19px;
  font-weight: 800;
  margin: 34px 0 12px;
  padding-left: 10px;
  border-left: 4px solid var(--red);
  line-height: 1.4;
}
.article-body h3 {
  font-size: 16px;
  font-weight: 700;
  margin: 22px 0 6px;
}
.article-body h3.faq-q {
  color: var(--red-deep);
}
.article-body p {
  font-size: 16px;
  line-height: 1.9;
  color: var(--text);
  margin-bottom: 16px;
}
.article-body .body-link {
  color: #d94f86;
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(217, 79, 134, 0.45);
}
.article-body .body-link:hover {
  color: #c23a72;
  text-decoration-color: currentColor;
}
.article-body ul, .article-body ol {
  margin: 0 0 18px 4px;
  list-style: none;
}
.article-body ul li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
  margin-bottom: 10px;
}
.article-body ul li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 0.72em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--red);
}
.article-body ol { counter-reset: xhs-ol; }
.article-body ol li {
  position: relative;
  padding-left: 30px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
  margin-bottom: 12px;
  counter-increment: xhs-ol;
}
.article-body ol li::before {
  content: counter(xhs-ol);
  position: absolute;
  left: 0;
  top: 0.18em;
  width: 20px;
  height: 20px;
  border-radius: 6px;
  background: var(--red);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}
.article-body blockquote {
  background: var(--red-tint);
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  margin: 22px 0;
  font-size: 16px;
  font-weight: 600;
  color: var(--red-deep);
  line-height: 1.8;
}

/* 话题标签 pills */
.note-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 26px 0 8px;
}
.note-tags .tag-pill {
  font-size: 13px;
  color: var(--red);
  background: var(--red-tint);
  border-radius: 999px;
  padding: 5px 12px;
  transition: background 0.15s;
}
.note-tags .tag-pill:hover { background: var(--red-soft); }

/* 互动条（点赞/收藏/评论） */
.interact {
  display: flex;
  gap: 10px;
  margin: 20px 0 4px;
}
.interact span {
  flex: 1;
  text-align: center;
  background: var(--card);
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 9px 0;
  font-size: 14px;
  color: var(--text-2);
}
.interact span:first-child { color: var(--red); border-color: var(--red-soft); background: var(--red-tint); }

/* CTA 引流卡 */
.cta {
  background: linear-gradient(135deg, var(--red) 0%, #FF6B8A 100%);
  border-radius: var(--radius);
  padding: 24px;
  margin: 26px 0;
  color: #fff;
}
.cta h3 { color: #fff; font-size: 18px; margin: 0 0 8px; }
.cta p { color: rgba(255, 255, 255, 0.9); font-size: 14px; margin-bottom: 16px; }
.cta a {
  display: inline-block;
  background: #fff;
  color: var(--red);
  font-weight: 700;
  font-size: 14px;
  border-radius: 999px;
  padding: 9px 22px;
}
.cta a:hover { background: var(--red-tint); }

/* 免责声明 */
.disclaimer {
  background: var(--card);
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  font-size: 13px;
  color: var(--text-3);
  line-height: 1.8;
  margin: 18px 0;
}

/* 相关推荐 */
.related { max-width: 720px; margin: 0 auto 40px; padding: 0 4px; }
.related .section-head h2 { font-size: 17px; border: 0; padding: 0; }

/* ============================================================
   归档列表页
   ============================================================ */

/* ============================================================
   页脚
   ============================================================ */
.footer { background: var(--card); border-top: 1px solid var(--line); margin-top: 20px; }
.footer .wrap {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 28px;
  padding: 32px 20px 24px;
}
.fbrand .fb-title { font-size: 17px; font-weight: 800; color: var(--red); }
.fbrand .fb-sub { font-size: 13px; color: var(--text-3); margin-top: 4px; }
.fcol h4 {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text);
}
.fcol a {
  display: block;
  font-size: 13px;
  color: var(--text-2);
  line-height: 2.05;
}
.fcol a:hover { color: var(--red); }
.copy {
  border-top: 1px solid var(--line);
  text-align: center;
  padding: 18px 20px 22px;
  font-size: 12px;
  color: var(--text-3);
  line-height: 1.9;
}
.copy .icp { display: block; }

/* ============================================================
   页面骨架：左侧栏 + 顶栏 + 瀑布流（参考小红书桌面版布局）
   ============================================================ */
:root {
  --side-w: 208px;   /* 左侧栏宽度 */
  --feed-w: 1240px;  /* 主内容最大宽度 */
}

.app {
  display: grid;
  grid-template-columns: var(--side-w) minmax(0, 1fr);
  min-height: 100vh;
  background: var(--bg);
}

/* ---------- 左侧栏 ---------- */
.side {
  position: sticky;
  top: 0;
  align-self: start;
  height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 20px 14px 16px;
  background: var(--card);
  border-right: 1px solid var(--line);
}
.logo {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 2px 10px 22px;
  font-size: 21px;
  font-weight: 800;
  color: var(--red);
  letter-spacing: -0.01em;
}
.logo-sub {
  font-size: 12px;
  font-weight: 700;
  color: #fff;
  background: var(--red);
  border-radius: 6px;
  padding: 1px 6px;
}
.snav { display: flex; flex-direction: column; gap: 2px; }
.snav a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 500;
  color: var(--text);
  transition: background 0.15s, color 0.15s;
}
.snav a:hover { background: var(--bg); color: var(--red); }
.snav a.on { background: var(--red-tint); color: var(--red); font-weight: 700; }
.snav .si { width: 20px; height: 20px; flex: none; }
.scta {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 42px;
  margin-top: 18px;
  border-radius: 10px;
  background: var(--red);
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  transition: background 0.15s;
}
.scta:hover { background: var(--red-deep); }
.sfoot {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 1px;
  padding: 18px 12px 2px;
}
.sfoot a { font-size: 12px; color: var(--text-3); line-height: 1.95; }
.sfoot a:hover { color: var(--red); }
.scopy { padding: 6px 12px 0; font-size: 11px; color: var(--text-3); line-height: 1.7; }

/* ---------- 右区 + 顶栏 ---------- */
.stage {
  display: flex;
  flex-direction: column;
  min-width: 0;
}
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(255, 255, 255, 0.93);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.topbar-row {
  display: flex;
  align-items: center;
  gap: 20px;
  height: 60px;
  padding: 0 28px;
}
.mini-logo { display: none; font-size: 18px; font-weight: 800; color: var(--red); }
.channels {
  display: flex;
  gap: 26px;
  flex: 1;
  overflow-x: auto;
  scrollbar-width: none;
}
.channels::-webkit-scrollbar { display: none; }
.channels a {
  font-size: 15px;
  color: var(--text-2);
  white-space: nowrap;
  padding: 3px 0;
  border-bottom: 2px solid transparent;
  transition: color 0.15s;
}
.channels a:hover { color: var(--red); }
.channels a.on { color: var(--text); font-weight: 700; border-bottom-color: var(--red); }
.topsearch {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 270px;
  flex: none;
  padding: 8px 14px;
  background: var(--bg);
  border: 1px solid transparent;
  border-radius: 999px;
  transition: background 0.15s, border-color 0.15s;
}
.topsearch:focus-within { background: #fff; border-color: var(--line-strong); }
.topsearch input {
  flex: 1;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  font-size: 13px;
  font-family: inherit;
  color: var(--text);
}
.ts-ico { width: 15px; height: 15px; flex: none; color: var(--text-3); order: 2; }

/* ---------- 横向滚动话题条 ---------- */
.topics { position: relative; padding: 0 28px 9px; }
.topics-inner {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}
.topics-inner::-webkit-scrollbar { display: none; }
.topic {
  flex: none;
  font-size: 12px;
  line-height: 1;
  color: var(--text-2);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 12px;
  white-space: nowrap;
  cursor: pointer;
  transition: color 0.15s, background 0.15s, border-color 0.15s;
}
.topic:hover { color: var(--red); border-color: #FFC2CE; background: #fff; }
.topic.on { color: #fff; background: var(--red); border-color: var(--red); font-weight: 600; }
/* 右侧渐隐提示可横向滚动 */
.topics::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 56px;
  height: calc(100% - 9px);
  background: linear-gradient(90deg, rgba(255, 255, 255, 0), rgba(255, 255, 255, 0.95));
  pointer-events: none;
}

/* ---------- 主体 ---------- */
.content {
  flex: 1;
  width: 100%;
  max-width: var(--feed-w);
  margin: 0 auto;
  padding: 0 28px 48px;
}

.feed-head { padding: 24px 2px 18px; }
.feed-head h1 { font-size: 22px; font-weight: 800; letter-spacing: -0.01em; }
.feed-head p { font-size: 13px; color: var(--text-3); margin-top: 6px; line-height: 1.75; }
.feed-meta { font-size: 12px; color: var(--text-3); margin-top: 4px; }
.feed-end { padding: 32px 0 8px; text-align: center; font-size: 13px; color: var(--text-3); }
.feed-end a { color: var(--red); }

/* 归档页顶部分类 chips */
.cat-filter { display: flex; flex-wrap: wrap; gap: 10px; margin: 6px 0 18px; }
.cat-filter a {
  font-size: 13px;
  padding: 6px 16px;
  border-radius: 999px;
  background: var(--card);
  border: 1px solid var(--line-strong);
  color: var(--text-2);
  transition: all 0.15s;
}
.cat-filter a:hover { border-color: var(--red); color: var(--red); }
.cat-filter a.active { background: var(--red); border-color: var(--red); color: #fff; font-weight: 600; }

/* ---------- 瀑布流 ---------- */
.masonry { columns: 4; column-gap: 16px; }

.note {
  display: block;
  break-inside: avoid;
  margin-bottom: 22px;
}
.note .thumb {
  aspect-ratio: 3 / 4;
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 20px 46px;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}
.note:hover .thumb { transform: translateY(-3px); box-shadow: var(--shadow-hover); }
.note:hover .thumb .temoji { transform: scale(1.08); }
.note:hover .n-desc { color: var(--text); }
.note .thumb .temoji { transition: transform 0.18s ease; }
.note:active .thumb { transform: translateY(-1px); }
.note .thumb .temoji {
  position: absolute;
  left: 16px;
  bottom: 14px;
  top: auto;
  transform: none;
  font-size: 38px;
  line-height: 1;
}
.note .n-info { padding: 10px 2px 0; }
.note .n-desc {
  font-size: 13px;
  color: var(--text);
  line-height: 1.55;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.note .n-foot { display: flex; align-items: center; gap: 6px; margin-top: 8px; }
.note .n-ava {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--red);
  color: #fff;
  font-size: 10px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex: none;
}
.note .n-name {
  font-size: 12px;
  color: var(--text-3);
  flex: 1;
  min-width: 0;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}
.note .n-time {
  flex: none;
  font-size: 12px;
  color: var(--text-3);
  white-space: nowrap;
}
.note .n-time::before { content: "· "; }
.note .n-like {
  margin-left: auto;
  flex: none;
  display: flex;
  align-items: center;
  gap: 3px;
  font-size: 12px;
  color: var(--text-3);
}
.note .n-like::before { content: "♡"; font-size: 13px; }
.note:hover .n-like::before { content: "❤"; color: var(--red); }

/* 相关阅读（文章页底部，3 列小网格） */
.rel-grid { columns: 3; }
.related .masonry { margin-top: 4px; }

/* ---------- 空搜索结果 ---------- */
.empty {
  display: none;
  text-align: center;
  padding: 70px 20px 90px;
  color: var(--text-3);
}
.empty .e-emoji { font-size: 40px; }
.empty .e-title { margin-top: 12px; font-size: 15px; color: var(--text-2); font-weight: 600; }
.empty .e-sub { margin-top: 6px; font-size: 13px; }
.empty a { color: var(--red); text-decoration: none; }
.empty a:hover { text-decoration: underline; }

/* ---------- 回到顶部 ---------- */
.back-top {
  position: fixed;
  right: 22px;
  bottom: 26px;
  z-index: 60;
  width: 42px;
  height: 42px;
  border: 0;
  border-radius: 50%;
  background: #fff;
  color: var(--text-2);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.2s, transform 0.2s, visibility 0.2s, color 0.15s;
}
.back-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-top:hover { color: var(--red); }
.back-top svg { width: 17px; height: 17px; }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1280px) {
  .masonry { columns: 3; }
  .rel-grid { columns: 3; }
}
@media (max-width: 1080px) {
  .app { grid-template-columns: minmax(0, 1fr); }
  .side { display: none; }
  .mini-logo { display: block; flex: none; }
  .topbar-row { padding: 0 18px; gap: 16px; }
  .topics { padding: 0 18px 8px; }
  .content { padding: 0 18px 40px; }
}
@media (max-width: 860px) {
  .masonry { columns: 2; }
  .rel-grid { columns: 2; }
  .note .thumb { padding: 32px 16px 40px; }
  .note .thumb .temoji { font-size: 32px; }
  .footer .wrap { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 600px) {
  .masonry { columns: 2; column-gap: 12px; }
  .note { margin-bottom: 16px; }
  .note .n-desc { font-size: 12px; -webkit-line-clamp: 2; }
  .topsearch { display: none; }
  .channels { gap: 20px; }
  .topbar-row { padding: 0 14px; }
  .topics { padding: 0 14px 7px; }
  .feed-head h1 { font-size: 19px; }
  .article-head h1 { font-size: 22px; }
  .article-cover { max-width: 100%; }
  .article-cover .cover-inner { padding: 34px 18px 44px; }
  .article-cover .cover-inner .ctitle { font-size: calc(var(--ct, 24px) * 0.78); }
  .footer .wrap { grid-template-columns: 1fr; gap: 22px; }
  .article-body p { font-size: 15px; }
  .back-top { right: 14px; bottom: 18px; }
}