/* ── AI Morning Brief · 阅读样式 ── */
/* 手机优先，无框架，纯 CSS */

:root {
  --bg: #0f0f0f;
  --bg-card: #1a1a1a;
  --bg-hover: #242424;
  --text: #e8e6e3;
  --text-secondary: #9a9a9a;
  --text-muted: #666;
  --accent: #6c9eff;
  --accent-dim: #4a7adb;
  --border: #2a2a2a;
  --tag-bg: #1e2a3a;
  --tag-text: #7aafff;
  --gradient-start: #6c9eff;
  --gradient-end: #a06cff;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', sans-serif;
  --font-serif: 'Noto Serif SC', Georgia, serif;
  --max-width: 680px;
  --radius: 12px;
  --radius-sm: 8px;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.7;
  min-height: 100vh;
}

/* ── 头部 ── */
.site-header {
  text-align: center;
  padding: 2rem 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

.site-header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.site-header .date {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-top: 0.25rem;
}

/* ── 导航 ── */
.nav-back {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  color: var(--accent);
  text-decoration: none;
  font-size: 0.875rem;
  padding: 1rem;
}

.nav-back:hover {
  color: var(--gradient-end);
}

/* ── 文章列表（目录页） ── */
.article-list {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem;
}

.article-card {
  display: block;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-bottom: 0.75rem;
  text-decoration: none;
  color: var(--text);
  transition: background 0.2s, border-color 0.2s, transform 0.15s;
}

.article-card:hover {
  background: var(--bg-hover);
  border-color: var(--accent-dim);
  transform: translateY(-1px);
}

.article-card .headline {
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.5;
  margin-bottom: 0.5rem;
}

.article-card .oneliner {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 0.75rem;
}

.article-card .meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.article-card .source-name {
  color: var(--accent);
}

.tag {
  display: inline-block;
  background: var(--tag-bg);
  color: var(--tag-text);
  font-size: 0.7rem;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  font-weight: 500;
}

/* ── 分区标题 ── */
.section-title {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem 1rem 0;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
}

.section-desc {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.25rem 1rem 0.75rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ── 信号雷达 ── */
.signal-radar {
  max-width: var(--max-width);
  margin: 0 auto;
}

.signal-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 3px solid;
  border-image: linear-gradient(180deg, #ff6c6c, #ffa06c) 1;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 0 1rem 0.75rem;
  padding: 1rem 1.25rem;
  animation: fadeIn 0.3s ease both;
}

.signal-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

.signal-topic {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.4;
}

.signal-tags {
  display: flex;
  gap: 0.25rem;
  flex-shrink: 0;
}

.signal-context {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0.75rem;
}

.signal-tweets {
  border-top: 1px solid var(--border);
  padding-top: 0.5rem;
}

.signal-tweet {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.35rem 0;
  text-decoration: none;
  color: var(--text);
  font-size: 0.8rem;
  line-height: 1.4;
  transition: color 0.2s;
}

.signal-tweet:hover {
  color: var(--accent);
}

.tweet-author {
  color: var(--accent);
  font-weight: 500;
  white-space: nowrap;
  flex-shrink: 0;
}

.tweet-text {
  color: var(--text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.signal-tweet:hover .tweet-text {
  color: var(--text-secondary);
}

/* ── 文章页 ── */
.article-page {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1rem 3rem;
}

.article-page .article-header {
  padding: 1.5rem 0 1rem;
}

.article-page .headline {
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 0.75rem;
}

.article-page .article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.article-page .hero-image {
  width: 100%;
  border-radius: var(--radius);
  margin-bottom: 1.5rem;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.article-page .body {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.9;
  color: var(--text);
}

.article-page .body p {
  margin-bottom: 1.25rem;
}

.article-page .source-link {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  margin-top: 1.5rem;
  padding: 0.6rem 1.2rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--accent);
  text-decoration: none;
  font-size: 0.85rem;
  transition: background 0.2s, border-color 0.2s;
}

.article-page .source-link:hover {
  background: var(--bg-hover);
  border-color: var(--accent-dim);
}

/* ── 页脚 ── */
.site-footer {
  text-align: center;
  padding: 2rem 1rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  margin-top: 2rem;
}

.site-footer a {
  color: var(--accent);
  text-decoration: none;
}

/* ── 统计 ── */
.stats {
  max-width: var(--max-width);
  margin: 1rem auto;
  padding: 0.75rem 1rem;
  display: flex;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.stats .stat-item {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.stats .stat-num {
  color: var(--accent);
  font-weight: 600;
}

/* ── 响应式：大屏微调 ── */
@media (min-width: 768px) {
  .article-page .headline {
    font-size: 1.75rem;
  }

  .article-page .body {
    font-size: 1.1rem;
  }

  .article-card {
    padding: 1.5rem;
  }

  .signal-card {
    padding: 1.25rem 1.5rem;
  }
}

/* ── 动画 ── */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.article-card,
.signal-card {
  animation: fadeIn 0.3s ease both;
}

.signal-card:nth-child(1) { animation-delay: 0s; }
.signal-card:nth-child(2) { animation-delay: 0.06s; }
.signal-card:nth-child(3) { animation-delay: 0.12s; }
.signal-card:nth-child(4) { animation-delay: 0.18s; }
.signal-card:nth-child(5) { animation-delay: 0.24s; }

.article-card:nth-child(1) { animation-delay: 0s; }
.article-card:nth-child(2) { animation-delay: 0.05s; }
.article-card:nth-child(3) { animation-delay: 0.1s; }
.article-card:nth-child(4) { animation-delay: 0.15s; }
.article-card:nth-child(5) { animation-delay: 0.2s; }
.article-card:nth-child(6) { animation-delay: 0.25s; }