/* ========== AI 每周简报 · 全站公用样式 ==========
   风格：Stratechery 极简学术
   主题色：仅一抹绿 #2D8B3E
*/
:root {
  --green: #2D8B3E;
  --green-soft: #E8F3EA;
  --text: #1F2937;
  --text-soft: #4B5563;
  --text-faint: #9CA3AF;
  --line: #E5E7EB;
  --line-strong: #1F2937;
  --bg: #FFFFFF;
  --bg-soft: #F8F9FA;

  --fs-h1: 30px;
  --fs-h2: 22px;
  --fs-h3: 17px;
  --fs-body: 15.5px;
  --fs-small: 14px;
  --fs-tiny: 12.5px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", Georgia, "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: #ECEDEF;
  line-height: 1.85;
  font-size: var(--fs-body);
  -webkit-font-smoothing: antialiased;
}

.page {
  max-width: 760px;
  margin: 32px auto;
  background: var(--bg);
  padding: 64px 72px 72px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.04);
}

/* ===== 报头 ===== */
.masthead { margin-bottom: 32px; }
.masthead-kicker {
  color: var(--green);
  font-size: var(--fs-tiny);
  letter-spacing: 2.5px;
  font-weight: 600;
  text-transform: uppercase;
  margin-bottom: 12px;
}
.masthead-title {
  font-size: var(--fs-h1);
  font-weight: 700;
  line-height: 1.35;
  margin-bottom: 10px;
  color: var(--text);
}
.masthead-meta {
  color: var(--text-faint);
  font-size: var(--fs-small);
  border-bottom: 1px solid var(--line);
  padding-bottom: 24px;
}

/* ===== 一句话总览 ===== */
.lead {
  border-left: 3px solid var(--green);
  background: var(--green-soft);
  padding: 18px 22px;
  margin: 32px 0 40px;
  color: var(--text);
  font-size: 15.5px;
  line-height: 1.85;
}
.lead strong { color: var(--green); font-weight: 700; }

/* ===== 章节标题 ===== */
h2.section-title {
  font-size: var(--fs-h2);
  font-weight: 700;
  margin: 48px 0 8px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--green);
  display: flex;
  align-items: baseline;
  gap: 10px;
}
h2.section-title .icon { font-size: 20px; line-height: 1; }
h2.section-title .en {
  font-size: var(--fs-small);
  color: var(--text-faint);
  font-weight: 400;
  letter-spacing: 0.5px;
  margin-left: auto;
}

/* ===== 子标题 ===== */
h3.item-title {
  font-size: var(--fs-h3);
  font-weight: 700;
  margin: 28px 0 10px;
  color: var(--text);
  line-height: 1.5;
}
h3.item-title .num { color: var(--green); margin-right: 6px; }

h4.subcat-title {
  font-size: var(--fs-body);
  font-weight: 700;
  margin: 28px 0 12px;
  color: var(--text);
  padding-left: 10px;
  border-left: 3px solid var(--green);
}

/* ===== 段落 / 列表 ===== */
p { margin-bottom: 12px; line-height: 1.85; text-align: justify; }
p.body-text { margin-bottom: 10px; }

ul.compact {
  list-style: none;
  margin: 8px 0 14px;
  padding-left: 0;
}
ul.compact li {
  padding: 4px 0 4px 18px;
  position: relative;
  line-height: 1.8;
}
ul.compact li::before {
  content: "·";
  position: absolute;
  left: 6px;
  top: 0;
  color: var(--green);
  font-weight: 700;
  font-size: 18px;
}

.meta-line {
  font-size: var(--fs-small);
  color: var(--text-soft);
  margin-bottom: 10px;
}
.meta-line strong { color: var(--text); }
/* 来源行的链接：默认完全融入灰字，hover 才显形 */
.meta-line a {
  color: inherit;
  border-bottom: none;
  text-decoration: none;
  transition: color 0.15s ease, border-bottom-color 0.15s ease;
}
.meta-line a:hover {
  color: var(--green);
  border-bottom: 1px solid var(--green);
}

.body-block { margin-bottom: 10px; line-height: 1.85; }
.body-block strong { color: var(--text); font-weight: 700; }

.perspective {
  background: var(--bg-soft);
  border-left: 3px solid var(--green);
  padding: 12px 18px;
  margin: 12px 0 8px;
  font-size: var(--fs-small);
  line-height: 1.8;
  color: var(--text-soft);
}
.perspective strong { color: var(--text); font-weight: 700; }
.perspective .label { color: var(--green); font-weight: 700; margin-right: 4px; }

a {
  color: var(--green);
  text-decoration: none;
  border-bottom: 1px dotted var(--green);
}
a:hover { border-bottom-style: solid; }

.em-num { color: var(--green); font-weight: 700; }

hr.divider {
  border: none;
  border-top: 1px solid var(--line);
  margin: 40px 0;
}

.footnote-block {
  background: var(--bg-soft);
  padding: 18px 22px;
  border-radius: 4px;
  font-size: var(--fs-small);
  color: var(--text-soft);
  line-height: 1.8;
  margin-top: 18px;
}
.footnote-block strong { color: var(--text); font-weight: 700; }
.footnote-block ul { list-style: disc; padding-left: 22px; margin: 8px 0; }
.footnote-block li { padding: 3px 0; }

.footer {
  margin-top: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  color: var(--text-faint);
  font-size: var(--fs-small);
  text-align: center;
  line-height: 1.7;
}

/* ===== 首页归档列表 ===== */
.archive-section {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}
.archive-list {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
}
.archive-list li {
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}
.archive-list li:last-child { border-bottom: none; }
.archive-list .archive-link {
  display: block;
  border-bottom: none;
  color: var(--text);
}
.archive-list .archive-link:hover .archive-title { color: var(--green); }
.archive-week {
  display: inline-block;
  color: var(--green);
  font-weight: 700;
  font-size: var(--fs-small);
  letter-spacing: 1px;
  margin-right: 12px;
  min-width: 56px;
}
.archive-date {
  color: var(--text-faint);
  font-size: var(--fs-small);
  margin-right: 12px;
}
.archive-title {
  color: var(--text);
  font-weight: 600;
  transition: color 0.15s;
}
.archive-summary {
  display: block;
  margin-top: 6px;
  margin-left: 68px;
  color: var(--text-soft);
  font-size: var(--fs-small);
  line-height: 1.7;
}
.archive-empty {
  color: var(--text-faint);
  font-size: var(--fs-small);
  padding: 16px 0;
  text-align: center;
}

/* 首页"最新一期"标签 */
.latest-badge {
  display: inline-block;
  background: var(--green);
  color: white;
  font-size: var(--fs-tiny);
  letter-spacing: 1px;
  padding: 2px 8px;
  border-radius: 2px;
  margin-left: 8px;
  vertical-align: middle;
}

/* "查看全部 →"按钮 */
.view-all-link {
  display: inline-block;
  margin-top: 8px;
  color: var(--text-soft);
  font-size: var(--fs-small);
  border-bottom: 1px dotted var(--text-faint);
}
.view-all-link:hover { color: var(--green); border-bottom-color: var(--green); }

@media (max-width: 720px) {
  .page { padding: 32px 22px; margin: 0; }
  .masthead-title { font-size: 22px; }
  h2.section-title { font-size: 18px; flex-wrap: wrap; }
  h2.section-title .en { margin-left: 0; width: 100%; }
  .archive-summary { margin-left: 0; }
}