/* ============================================================
   M3Blog — Material Design 3 风格
   ============================================================ */

/* ---------- Design Tokens ---------- */
:root {
  --md-primary: #6750a4;
  --md-on-primary: #ffffff;
  --md-primary-container: #eaddff;
  --md-on-primary-container: #21005d;
  --md-secondary: #625b71;
  --md-secondary-container: #e8def8;
  --md-on-secondary-container: #1d192b;
  --md-tertiary: #7d5260;
  --md-tertiary-container: #ffd8e4;
  --md-on-tertiary-container: #31111d;
  --md-error: #b3261e;
  --md-on-error: #ffffff;
  --md-error-container: #f9dedc;
  --md-on-error-container: #410e0b;

  --md-surface: #fffbfe;
  --md-surface-container-low: #f7f2fa;
  --md-surface-container: #f3edf7;
  --md-surface-container-high: #ece6f0;
  --md-surface-variant: #e7e0ec;
  --md-on-surface: #1c1b1f;
  --md-on-surface-variant: #49454f;
  --md-outline: #79747e;
  --md-outline-variant: #cac4d0;

  --md-inverse-surface: #313033;
  --md-inverse-on-surface: #f4eff4;

  /* 形状 */
  --shape-xs: 4px;
  --shape-sm: 8px;
  --shape-md: 12px;
  --shape-lg: 16px;
  --shape-xl: 28px;
  --shape-full: 999px;

  /* 阴影（elevation） */
  --elev-1: 0 1px 2px rgba(0,0,0,.3), 0 1px 3px 1px rgba(0,0,0,.15);
  --elev-2: 0 1px 2px rgba(0,0,0,.3), 0 2px 6px 2px rgba(0,0,0,.15);
  --elev-3: 0 4px 8px 3px rgba(0,0,0,.15), 0 1px 3px rgba(0,0,0,.3);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
               "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

[data-theme="dark"] {
  --md-primary: #d0bcff;
  --md-on-primary: #381e72;
  --md-primary-container: #4f378b;
  --md-on-primary-container: #eaddff;
  --md-secondary: #ccc2dc;
  --md-secondary-container: #4a4458;
  --md-on-secondary-container: #e8def8;
  --md-tertiary: #efb8c8;
  --md-tertiary-container: #633b48;
  --md-on-tertiary-container: #ffd8e4;
  --md-error: #f2b8b5;
  --md-on-error: #601410;
  --md-error-container: #8c1d18;
  --md-on-error-container: #f9dedc;

  --md-surface: #141218;
  --md-surface-container-low: #1d1b20;
  --md-surface-container: #211f26;
  --md-surface-container-high: #2b2930;
  --md-surface-variant: #49454f;
  --md-on-surface: #e6e1e5;
  --md-on-surface-variant: #cac4d0;
  --md-outline: #938f99;
  --md-outline-variant: #49454f;

  --md-inverse-surface: #e6e1e5;
  --md-inverse-on-surface: #313033;

  --elev-1: 0 1px 2px rgba(0,0,0,.6), 0 1px 3px 1px rgba(0,0,0,.4);
  --elev-2: 0 1px 2px rgba(0,0,0,.6), 0 2px 6px 2px rgba(0,0,0,.4);
  --elev-3: 0 4px 8px 3px rgba(0,0,0,.5), 0 1px 3px rgba(0,0,0,.6);
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--md-surface);
  color: var(--md-on-surface);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background-color .35s ease, color .35s ease, opacity .18s ease;
}
a { color: var(--md-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; }
::selection { background: var(--md-primary-container); color: var(--md-on-primary-container); }

.icon { display: inline-block; vertical-align: -0.15em; flex-shrink: 0; }

/* Material Symbols 图标字体（Google Fonts，可变字体） */
.material-symbols-rounded {
  font-family: 'Material Symbols Rounded';
  font-weight: normal;
  font-style: normal;
  display: inline-block;
  line-height: 1;
  letter-spacing: normal;
  text-transform: none;
  white-space: nowrap;
  word-wrap: normal;
  direction: ltr;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
  vertical-align: -0.15em;
  flex-shrink: 0;
}
.material-symbols-rounded.filled { font-variation-settings: 'FILL' 1, 'wght' 400, 'GRAD' 0, 'opsz' 24; }

/* ---------- 布局容器 ---------- */
.site-main { min-height: calc(100vh - 200px); }
.container { width: 100%; max-width: 860px; margin: 0 auto; padding: 0 20px; }
.container--narrow { max-width: 760px; }
.container--wide { max-width: 1080px; }

.page-hero {
  padding: 40px 0 24px;
}
.page-hero h1 {
  margin: 0 0 8px;
  font-size: 2rem;
  letter-spacing: -0.5px;
}
.page-hero p { margin: 0; color: var(--md-on-surface-variant); }

/* ---------- 顶部进度条 ---------- */
.progress-bar {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0;
  background: var(--md-primary);
  z-index: 1000;
  opacity: 0;
  transition: opacity .3s ease, width .1s linear;
}
.progress-bar.is-visible { opacity: 1; }

/* ---------- App Bar ---------- */
.app-bar {
  position: sticky;
  top: 0;
  z-index: 500;
  background: var(--md-surface);
  background: color-mix(in srgb, var(--md-surface) 88%, transparent);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--md-outline-variant);
}
.app-bar__row {
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: 1080px;
  margin: 0 auto;
  padding: 8px 16px;
  height: 64px;
}
.app-bar__brand { display: flex; align-items: center; gap: 8px; color: var(--md-on-surface); font-weight: 600; font-size: 1.05rem; }
.app-bar__brand:hover { text-decoration: none; }
.brand__logo { display: grid; place-items: center; width: 34px; height: 34px; border-radius: var(--shape-md); background: var(--md-primary-container); color: var(--md-on-primary-container); }
.app-bar__actions { margin-left: auto; display: flex; align-items: center; gap: 4px; }
.app-bar__menu { display: none; }

/* ---------- 顶部导航 ---------- */
.top-nav { display: flex; align-items: center; gap: 2px; margin-left: 12px; }
.top-nav__item {
  position: relative;
  padding: 10px 14px;
  border-radius: var(--shape-full);
  color: var(--md-on-surface-variant);
  font-weight: 500;
  font-size: .92rem;
  transition: background-color .2s ease, color .2s ease;
}
.top-nav__item:hover { background: var(--md-surface-container); color: var(--md-on-surface); text-decoration: none; }
.top-nav__item.is-active { color: var(--md-primary); }
.top-nav__item.is-active::after {
  content: "";
  position: absolute;
  left: 14px; right: 14px; bottom: 4px;
  height: 3px;
  border-radius: var(--shape-full);
  background: var(--md-primary);
}

/* ---------- 图标按钮 ---------- */
.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 40px; height: 40px;
  border: none;
  border-radius: var(--shape-full);
  background: transparent;
  color: var(--md-on-surface-variant);
  cursor: pointer;
  transition: background-color .2s ease;
}
.icon-btn:hover { background: color-mix(in srgb, var(--md-on-surface) 8%, transparent); color: var(--md-on-surface); }
.icon-btn:active { background: color-mix(in srgb, var(--md-on-surface) 12%, transparent); }

/* ---------- 搜索框 ---------- */
.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  height: 40px;
  padding: 0 12px;
  margin-right: 4px;
  border-radius: var(--shape-full);
  background: var(--md-surface-container);
  color: var(--md-on-surface-variant);
  transition: width .25s ease, box-shadow .2s ease;
}
.search-box__icon { display: grid; place-items: center; }
.search-box input {
  border: none;
  background: transparent;
  color: var(--md-on-surface);
  font: inherit;
  width: 160px;
  outline: none;
}
.search-box input::placeholder { color: var(--md-on-surface-variant); }
.search-box:focus-within { box-shadow: 0 0 0 2px var(--md-primary); }
#searchToggle { display: none; }

/* ---------- 抽屉（移动端） ---------- */
.drawer {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: 300px;
  max-width: 85vw;
  background: var(--md-surface);
  z-index: 900;
  transform: translateX(-105%);
  transition: transform .28s cubic-bezier(.2,0,0,1);
  padding: 16px 12px;
  border-radius: 0 var(--shape-lg) var(--shape-lg) 0;
  box-shadow: var(--elev-3);
}
.drawer.is-open { transform: translateX(0); }
.drawer__head { display: flex; align-items: center; justify-content: space-between; padding: 4px 8px 16px; }
.drawer__nav { display: flex; flex-direction: column; gap: 4px; }
.drawer__item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 16px;
  border-radius: var(--shape-full);
  color: var(--md-on-surface-variant);
  font-weight: 500;
}
.drawer__item:hover { background: var(--md-surface-container); color: var(--md-on-surface); text-decoration: none; }
.drawer__item.is-active { background: var(--md-secondary-container); color: var(--md-on-secondary-container); }
.scrim {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.4);
  z-index: 850;
  opacity: 0;
  transition: opacity .25s ease;
}
.scrim.is-show { opacity: 1; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 40px;
  padding: 0 24px;
  border: none;
  border-radius: var(--shape-full);
  font: inherit;
  font-weight: 500;
  font-size: .92rem;
  cursor: pointer;
  transition: box-shadow .2s ease, background-color .2s ease, opacity .2s ease;
}
.btn:hover { text-decoration: none; }
.btn--filled { background: var(--md-primary); color: var(--md-on-primary); }
.btn--filled:hover { box-shadow: var(--elev-1); }
.btn--tonal { background: var(--md-secondary-container); color: var(--md-on-secondary-container); }
.btn--outlined { background: transparent; color: var(--md-primary); box-shadow: inset 0 0 0 1px var(--md-outline); }
.btn--text { background: transparent; color: var(--md-primary); padding: 0 12px; }
.btn--error { background: var(--md-error); color: var(--md-on-error); }
.btn--sm { height: 32px; padding: 0 16px; font-size: .85rem; }

/* ---------- 卡片 ---------- */
.card {
  background: var(--md-surface-container-low);
  border: 1px solid var(--md-outline-variant);
  border-radius: var(--shape-md);
  overflow: hidden;
  transition: transform .2s ease, box-shadow .2s ease;
}
.card--hover:hover { transform: translateY(-2px); box-shadow: var(--elev-2); }

/* ---------- 文章列表 ---------- */
.post-list { display: flex; flex-direction: column; gap: 16px; padding: 8px 0 32px; }
.post-card { display: flex; gap: 20px; align-items: center; padding: 20px 24px; color: inherit; }
.post-card:hover { text-decoration: none; }
.post-card__body { flex: 1; min-width: 0; }
.post-card__cover {
  flex-shrink: 0;
  width: 200px;
  aspect-ratio: 4 / 3;
  border-radius: var(--shape-md);
  overflow: hidden;
  background: var(--md-surface-container);
}
.post-card__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform .45s cubic-bezier(.2, 0, 0, 1);
}
.post-card:hover .post-card__cover img { transform: scale(1.05); }
.post-card__meta { display: flex; flex-wrap: wrap; align-items: center; gap: 14px; color: var(--md-on-surface-variant); font-size: .85rem; margin-bottom: 10px; }
.post-card__meta .m { display: inline-flex; align-items: center; gap: 5px; }
.post-card__title { margin: 0 0 8px; font-size: 1.3rem; line-height: 1.35; }
.post-card__title a { color: var(--md-on-surface); }
.post-card__title a:hover { color: var(--md-primary); }
.post-card__desc { margin: 0 0 14px; color: var(--md-on-surface-variant); }

/* ---------- Chip ---------- */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  height: 30px;
  padding: 0 12px;
  border-radius: var(--shape-sm);
  border: 1px solid var(--md-outline-variant);
  color: var(--md-on-surface-variant);
  font-size: .82rem;
  background: transparent;
  transition: background-color .2s ease;
}
.chip:hover { background: var(--md-surface-container-high); color: var(--md-on-surface); text-decoration: none; }
.chip--primary { background: var(--md-primary-container); border-color: transparent; color: var(--md-on-primary-container); }
.chip-group { display: flex; flex-wrap: wrap; gap: 8px; }

/* ---------- 文章详情 ---------- */
.article-header { padding: 32px 0 8px; }
.article-header h1 { margin: 16px 0 12px; font-size: 2rem; line-height: 1.25; letter-spacing: -0.5px; }
.article-header .post-card__meta { font-size: .9rem; }
.article-cover {
  margin: 0 0 8px;
  border-radius: var(--shape-lg);
  overflow: hidden;
  background: var(--md-surface-container);
}
.article-cover img {
  width: 100%;
  display: block;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.markdown-body {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--md-on-surface);
}
.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4 {
  line-height: 1.35;
  margin: 2em 0 .7em;
  letter-spacing: -0.3px;
}
.markdown-body h1 { font-size: 1.7rem; }
.markdown-body h2 { font-size: 1.45rem; padding-bottom: .3em; border-bottom: 1px solid var(--md-outline-variant); }
.markdown-body h3 { font-size: 1.2rem; }
.markdown-body p { margin: 0 0 1.1em; }
.markdown-body a { text-decoration: underline; text-underline-offset: 3px; }
.markdown-body strong { font-weight: 650; }
.markdown-body blockquote {
  margin: 1.4em 0;
  padding: .6em 1.2em;
  border-left: 4px solid var(--md-primary);
  background: var(--md-surface-container);
  border-radius: 0 var(--shape-sm) var(--shape-sm) 0;
  color: var(--md-on-surface-variant);
}
.markdown-body blockquote p { margin: 0; }
.markdown-body ul, .markdown-body ol { padding-left: 1.5em; margin: 0 0 1.1em; }
.markdown-body li { margin: .3em 0; }
.markdown-body code {
  font-family: var(--font-mono);
  font-size: .88em;
  background: var(--md-surface-container-high);
  color: var(--md-on-surface);
  padding: .15em .4em;
  border-radius: var(--shape-xs);
}
.markdown-body pre {
  background: var(--md-inverse-surface);
  color: var(--md-inverse-on-surface);
  padding: 16px 18px;
  border-radius: var(--shape-md);
  overflow-x: auto;
  margin: 1.4em 0;
}
.markdown-body pre code { background: transparent; color: inherit; padding: 0; font-size: .88rem; line-height: 1.6; }
.markdown-body img { border-radius: var(--shape-md); display: block; margin: 1.4em auto; }
.markdown-body hr { border: none; border-top: 1px solid var(--md-outline-variant); margin: 2em 0; }
.markdown-body table { border-collapse: collapse; width: 100%; margin: 1.4em 0; }
.markdown-body th, .markdown-body td { border: 1px solid var(--md-outline-variant); padding: 8px 12px; text-align: left; }
.markdown-body th { background: var(--md-surface-container); }

/* ---------- 文章底部 ---------- */
.article-footer { margin: 40px 0 24px; padding-top: 24px; border-top: 1px solid var(--md-outline-variant); }
.article-footer__tags { display: flex; flex-wrap: wrap; gap: 8px; }

/* ---------- 相关文章 ---------- */
.related { margin: 32px 0 48px; }
.related h2 { font-size: 1.25rem; margin: 0 0 16px; }
.related-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.related-card { display: block; padding: 16px; }
.related-card h3 { margin: 0 0 6px; font-size: 1rem; line-height: 1.4; color: var(--md-on-surface); }
.related-card .post-card__meta { font-size: .78rem; margin: 0; }

/* ---------- 分页 ---------- */
.pagination { display: flex; align-items: center; justify-content: center; gap: 8px; padding: 16px 0 40px; }
.pagination .btn { min-width: 40px; }

/* ---------- 空状态 ---------- */
.empty {
  text-align: center;
  padding: 64px 20px;
  color: var(--md-on-surface-variant);
}
.empty .icon { font-size: 3rem; opacity: .4; }

/* ---------- 分类/标签页 ---------- */
.taxonomy-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; padding: 24px 0 40px; }
.taxonomy-card { display: flex; align-items: center; gap: 14px; padding: 18px; color: inherit; }
.taxonomy-card:hover { text-decoration: none; }
.taxonomy-card__icon { display: grid; place-items: center; width: 44px; height: 44px; border-radius: var(--shape-md); background: var(--md-primary-container); color: var(--md-on-primary-container); flex-shrink: 0; }
.taxonomy-card__name { font-weight: 600; }
.taxonomy-card__count { font-size: .82rem; color: var(--md-on-surface-variant); }

.tag-cloud { display: flex; flex-wrap: wrap; gap: 10px; padding: 24px 0 40px; }
.tag-cloud .chip { height: 36px; font-size: .9rem; }

/* ---------- 卡片墙（Bento） ---------- */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-auto-rows: 130px;
  gap: 16px;
  padding: 24px 0 40px;
}
.bento-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 20px;
  border-radius: var(--shape-lg);
  color: var(--md-on-primary-container);
  overflow: hidden;
  transition: transform .2s ease, box-shadow .2s ease;
}
.bento-card:hover { transform: translateY(-3px); box-shadow: var(--elev-2); text-decoration: none; color: inherit; }
.bento-card--primary { background: var(--md-primary-container); color: var(--md-on-primary-container); }
.bento-card--secondary { background: var(--md-secondary-container); color: var(--md-on-secondary-container); }
.bento-card--tertiary { background: var(--md-tertiary-container); color: var(--md-on-tertiary-container); }
.bento-card--surface { background: var(--md-surface-container-high); color: var(--md-on-surface); }
.bento-card[data-size="2x1"] { grid-column: span 2; }
.bento-card[data-size="1x2"] { grid-row: span 2; }
.bento-card[data-size="2x2"] { grid-column: span 2; grid-row: span 2; }
.bento-card__icon { display: grid; place-items: center; width: 40px; height: 40px; border-radius: var(--shape-full); background: color-mix(in srgb, currentColor 14%, transparent); margin-bottom: 12px; }
.bento-card__title { font-weight: 650; font-size: 1.05rem; }
.bento-card__desc { font-size: .9rem; margin-top: 4px; opacity: .85; }

/* ---------- 此刻页 ---------- */
.now-list { display: flex; flex-direction: column; gap: 14px; padding: 24px 0 40px; }
.now-item { display: flex; gap: 16px; padding: 18px 20px; align-items: flex-start; }
.now-item__icon { display: grid; place-items: center; width: 42px; height: 42px; border-radius: var(--shape-full); background: var(--md-primary-container); color: var(--md-on-primary-container); flex-shrink: 0; }
.now-item__label { font-size: .82rem; font-weight: 600; color: var(--md-primary); text-transform: uppercase; letter-spacing: .5px; }
.now-item__content { margin: 2px 0 0; }
.now-item__time { font-size: .78rem; color: var(--md-on-surface-variant); }

/* ---------- 关于/数字足迹 ---------- */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin: 24px 0 8px; }
.stat-card { text-align: center; padding: 24px 12px; }
.stat-card__value { font-size: 2rem; font-weight: 700; color: var(--md-primary); font-variant-numeric: tabular-nums; }
.stat-card__label { font-size: .85rem; color: var(--md-on-surface-variant); margin-top: 4px; }

/* ---------- Giscus 评论 ---------- */
.giscus-wrap { margin: 32px 0 48px; }

/* ---------- 页脚 ---------- */
.site-footer { border-top: 1px solid var(--md-outline-variant); background: var(--md-surface-container-low); margin-top: 48px; }
.site-footer__inner { max-width: 1080px; margin: 0 auto; padding: 32px 20px; display: flex; flex-wrap: wrap; gap: 24px; align-items: center; justify-content: space-between; }
.footer-brand__name { font-weight: 650; }
.footer-brand__desc { margin: 4px 0 0; font-size: .85rem; color: var(--md-on-surface-variant); }
.footer-links { display: flex; gap: 20px; }
.footer-links a { color: var(--md-on-surface-variant); font-size: .9rem; }
.footer-copy { width: 100%; font-size: .82rem; color: var(--md-on-surface-variant); margin: 0; }

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%) translateY(20px);
  background: var(--md-inverse-surface);
  color: var(--md-inverse-on-surface);
  padding: 12px 20px;
  border-radius: var(--shape-sm);
  font-size: .9rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s ease, transform .25s ease;
  z-index: 1100;
  box-shadow: var(--elev-2);
}
.toast.is-show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- 选中文字分享气泡 ---------- */
.share-pop {
  position: absolute;
  display: none;
  align-items: center;
  gap: 8px;
  background: var(--md-inverse-surface);
  color: var(--md-inverse-on-surface);
  border-radius: var(--shape-full);
  padding: 6px 8px 6px 16px;
  font-size: .82rem;
  box-shadow: var(--elev-3);
  z-index: 1200;
  white-space: nowrap;
}
.share-pop.is-show { display: flex; }
.share-pop .icon-btn { width: 32px; height: 32px; color: var(--md-inverse-on-surface); }

/* ---------- 主题切换过渡动画 ---------- */
::view-transition-old(root),
::view-transition-new(root) {
  animation: none;
  mix-blend-mode: normal;
}

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .top-nav { display: none; }
  .app-bar__menu { display: inline-grid; }
  .related-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .bento-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .search-box { display: none; }
  #searchToggle { display: inline-grid; }
  .app-bar__row { height: 56px; padding: 6px 8px; }
  .brand__name { display: none; }
  .page-hero h1, .article-header h1 { font-size: 1.6rem; }
  .related-grid { grid-template-columns: 1fr; }
  .post-card { padding: 16px; gap: 12px; }
  .post-card__cover { width: 96px; aspect-ratio: 1; }
  .markdown-body { font-size: 1rem; }
  .bento-grid { grid-template-columns: 1fr 1fr; grid-auto-rows: 110px; }
  .bento-card[data-size="2x1"], .bento-card[data-size="2x2"] { grid-column: span 2; }
}

/* ---------- 过渡动画 ---------- */
/* 涟漪宿主 */
.btn, .icon-btn, .chip, .top-nav__item, .drawer__item, .sidebar__item, .card, .bento-card {
  position: relative;
  overflow: hidden;
}

/* 涟漪（MD3 state layer） */
.ripple {
  position: absolute;
  border-radius: 50%;
  background: currentColor;
  opacity: .18;
  transform: scale(0);
  animation: m3-ripple .5s ease-out forwards;
  pointer-events: none;
}
@keyframes m3-ripple {
  to { transform: scale(1); opacity: 0; }
}

/* 滚动进入 */
.reveal {
  opacity: 0;
  transform: translateY(16px);
}
.reveal.is-visible {
  animation: m3-reveal .5s cubic-bezier(.2, 0, 0, 1) forwards;
}
@keyframes m3-reveal {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: none; }
}

/* 首屏 hero 淡入 */
@keyframes m3-fade-up {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: none; }
}
.page-hero {
  animation: m3-fade-up .45s cubic-bezier(.2, 0, 0, 1) both;
}

/* 页面切换过渡（不支持原生 View Transition 的浏览器走此 fallback） */
@keyframes m3-page-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}
.no-vt .site-main {
  animation: m3-page-in .32s cubic-bezier(.2, 0, 0, 1) both;
}
body.is-leaving {
  opacity: 0;
}

/* 同源页面导航过渡 */
@view-transition {
  navigation: auto;
}

/* ---------- 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1 !important; transform: none !important; }
  .page-hero { animation: none !important; }
}