/* ─── 字体声明 ─── */
@font-face {
  font-family: 'AlibabaPuHuiTi';
  src: url('../fonts/Alibaba-PuHuiTi-Heavy.ttf') format('truetype');
  font-weight: 900;
  font-display: swap;
}
@font-face {
  font-family: 'NotoSansSC';
  src: url('../fonts/NotoSansSC-Regular.otf') format('opentype');
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: 'NotoSansSC';
  src: url('../fonts/NotoSansSC-Light.otf') format('opentype');
  font-weight: 300;
  font-display: swap;
}

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

:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --text-muted: #555555;
  --text-faint: #999999;
  --border: #e5e5e5;
  --shadow: 0 1px 3px rgba(0,0,0,0.04);

  --blue-deep: #4A6FE2;
  --red-deep:  #e65a56;
  --accent:    #2563eb;
}

html, body {
  background: var(--bg);
  color: var(--text);
  font-family: 'NotoSansSC', -apple-system, BlinkMacSystemFont, 'Helvetica Neue', sans-serif;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 56px 32px 80px;
}

/* ─── 标题区 ─── */
.site-header {
  text-align: center;
  margin-bottom: 32px;
}
.site-title {
  font-family: 'AlibabaPuHuiTi', sans-serif;
  font-weight: 900;
  font-size: 44px;
  letter-spacing: 0.5px;
  color: var(--text);
  line-height: 1.2;
}
.site-subtitle {
  margin-top: 12px;
  font-size: 15px;
  font-weight: 300;
  color: var(--text-muted);
  letter-spacing: 0.3px;
}

/* ─── 数据更新时间(顶部显眼) ─── */
.freshness-strip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  padding: 8px 18px;
  border-radius: 999px;
  background: #f5f7fa;
  border: 1px solid #e5e7eb;
  font-size: 13px;
  font-weight: 400;
  color: var(--text);
}
.freshness-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #22c55e;
  box-shadow: 0 0 0 4px rgba(34,197,94,0.15);
}
.freshness-strip.is-stale .freshness-dot { background: #f59e0b; box-shadow: 0 0 0 4px rgba(245,158,11,0.15); }
.freshness-strip.is-old   .freshness-dot { background: #e65a56; box-shadow: 0 0 0 4px rgba(230,90,86,0.15); }
.freshness-text b {
  font-weight: 600;
  color: var(--text);
}
.freshness-hint {
  color: var(--text-muted);
  font-weight: 300;
  margin-left: 6px;
}

/* ─── 色条 ─── */
.legend-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin: 24px auto 28px;
  max-width: 480px;
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 300;
}
.legend-gradient {
  flex: 1;
  height: 12px;
  border-radius: 2px;
  background: linear-gradient(
    to right,
    #4A6FE2 0%,
    #C0CFFA 35%,
    #FFFFFF 50%,
    #F5C0BE 65%,
    #e65a56 100%
  );
  border: 1px solid var(--border);
  position: relative;
}
.legend-zero {
  position: relative;
  display: inline-block;
  min-width: 12px;
  text-align: center;
}

/* ─── 热力图 ─── */
.heatmap-wrap {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 20px 16px;
  overflow-x: auto;
}
#heatmap {
  display: block;
  width: 100%;
  height: auto;
}

/* ─── 操作栏 ─── */
.action-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: 24px;
  flex-wrap: wrap;
}
.btn-primary {
  font-family: inherit;
  font-size: 14px;
  font-weight: 400;
  padding: 11px 26px;
  background: var(--text);
  color: #ffffff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: transform .12s ease, background .18s ease;
  letter-spacing: 0.5px;
}
.btn-primary:hover { background: #000; transform: translateY(-1px); }
.btn-primary:active { transform: translateY(0); }
.btn-primary:disabled { opacity: 0.6; cursor: wait; }
.action-hint {
  font-size: 12px;
  font-weight: 300;
  color: var(--text-faint);
}

/* ─── 抄底数学题 section ─── */
.math-section {
  margin-top: 56px;
  padding-top: 40px;
  border-top: 1px solid var(--border);
}
.section-hdr {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 28px;
}
.section-title {
  font-family: 'AlibabaPuHuiTi', 'Microsoft YaHei', sans-serif;
  font-weight: 900;
  font-size: 32px;
  color: var(--text);
  letter-spacing: 0.4px;
  margin-bottom: 14px;
}
.section-desc {
  font-size: 14px;
  color: var(--text-muted);
  font-weight: 300;
  line-height: 1.85;
}
.loss-table-wrap {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 20px 16px;
  overflow-x: auto;
}
#lossTable {
  display: block;
  width: 100%;
  height: auto;
}
.loss-table-note {
  margin-top: 14px;
  font-size: 12.5px;
  color: var(--text-muted);
  font-weight: 300;
  text-align: center;
}
.loss-table-note b { color: #155a1a; font-weight: 600; }
.loss-table-note code {
  font-family: 'SF Mono', Menlo, monospace;
  font-size: 12px;
  padding: 1px 5px;
  background: #f4f5f7;
  border-radius: 3px;
}

/* ─── 页脚 ─── */
.site-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  font-weight: 300;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 12px;
}
.footer-left { display: flex; flex-direction: column; gap: 4px; }
.footer-note { font-size: 11px; color: var(--text-faint); }

/* ─── 口径说明 ─── */
.notes-block {
  margin-top: 28px;
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 300;
  line-height: 1.7;
}
.notes-block summary {
  cursor: pointer;
  color: var(--text);
  font-weight: 400;
  padding: 10px 0;
  user-select: none;
}
.notes-block summary:hover { color: var(--accent); }
.notes-block ul {
  margin-top: 8px;
  padding-left: 20px;
}
.notes-block li { margin-bottom: 6px; }

/* ─── 响应式 ─── */
@media (max-width: 768px) {
  .container { padding: 32px 12px 60px; }
  .site-title { font-size: 30px; }
  .site-subtitle { font-size: 13px; }
  .heatmap-wrap { padding: 12px 6px; }
  .site-footer { flex-direction: column; align-items: flex-start; }
}