:root {
    --bg: #faf9f6;
    --card-bg: #ffffff;
    --border: rgba(0,0,0,0.08);
    --text-primary: #2c2c2a;
    --text-secondary: #5f5e5a;
    --text-tertiary: #888780;
    --accent: #378ADD;
    --accent-2: #1D9E75;
    --warn: #BA7517;
    --radius: 10px;
  }
  @media (prefers-color-scheme: dark) {
    :root {
      --bg: #1c1c1a;
      --card-bg: #262624;
      --border: rgba(255,255,255,0.1);
      --text-primary: #ECECE6;
      --text-secondary: #B4B2A9;
      --text-tertiary: #888780;
    }
  }
  * { box-sizing: border-box; margin: 0; padding: 0; }
  body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    background: var(--bg);
    color: var(--text-primary);
    line-height: 1.6;
    padding: 2rem 1rem 4rem;
  }
  .wrap { max-width: 880px; margin: 0 auto; }
  header { margin-bottom: 2rem; }
  h1 { font-size: 22px; font-weight: 500; margin-bottom: 4px; }
  .subtitle { font-size: 14px; color: var(--text-secondary); }
  .toolbar { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 1.5rem; }
  button, .file-btn {
    font-size: 14px; padding: 8px 14px; border-radius: var(--radius);
    border: 0.5px solid var(--border); background: var(--card-bg);
    color: var(--text-primary); cursor: pointer; transition: background 0.15s;
  }
  button:hover, .file-btn:hover { background: rgba(128,128,128,0.08); }
  button.primary { background: var(--accent); color: white; border: none; }
  button.primary:hover { opacity: 0.9; }
  input[type=file] { display: none; }

  .metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-bottom: 1.5rem; }
  .metric { background: var(--card-bg); border: 0.5px solid var(--border); border-radius: var(--radius); padding: 14px 16px; }
  .metric-label { font-size: 13px; color: var(--text-secondary); margin-bottom: 6px; }
  .metric-value { font-size: 22px; font-weight: 500; }
  .metric-sub { font-size: 12px; color: var(--text-tertiary); margin-top: 2px; }
  .city-metrics { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; margin-bottom: 1.5rem; }

  .card { background: var(--card-bg); border: 0.5px solid var(--border); border-radius: 12px; padding: 1.25rem; margin-bottom: 1.25rem; }
  .section-title { font-size: 14px; font-weight: 500; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 1rem; }

  .chart-wrap { position: relative; width: 100%; }

  .timeline-row { display: flex; align-items: center; gap: 12px; padding: 8px 0; font-size: 14px; border-bottom: 0.5px solid var(--border); }
  .timeline-row:last-child { border-bottom: none; }
  .tl-dot { width: 9px; height: 9px; border-radius: 50%; flex-shrink: 0; }
  .tl-date { color: var(--text-secondary); min-width: 110px; font-size: 13px; font-variant-numeric: tabular-nums; white-space: nowrap; }
  .tl-city { font-weight: 500; min-width: 44px; }
  .tl-days { color: var(--text-secondary); font-size: 13px; min-width: 36px; }
  .tl-notes { font-size: 13px; color: var(--text-secondary); flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .tl-gap { font-size: 12px; color: var(--text-tertiary); white-space: nowrap; }
  .tl-gap.long { color: var(--warn); }
  .tl-del { font-size: 12px; color: var(--text-tertiary); cursor: pointer; padding: 2px 6px; }
  .tl-del:hover { color: #c0392b; }
  /* 桌面端：wrapper 透明，子元素直接参与父级 flex 布局 */
  .tl-main, .tl-meta { display: contents; }

  .legend { display: flex; gap: 16px; font-size: 13px; color: var(--text-secondary); margin-bottom: 10px; flex-wrap: wrap; }
  .legend-item { display: flex; align-items: center; gap: 5px; }
  .legend-dot { width: 8px; height: 8px; border-radius: 2px; }

  .add-form { display: grid; grid-template-columns: 1fr 1fr 80px 1.4fr auto; gap: 8px; align-items: end; }
  .add-form label { font-size: 12px; color: var(--text-secondary); display: block; margin-bottom: 4px; }
  .add-form input { width: 100%; height: 34px; padding: 0 10px; font-size: 14px; border-radius: 8px; border: 0.5px solid var(--border); background: var(--bg); color: var(--text-primary); }
  .add-form button { height: 34px; white-space: nowrap; }

  .empty-state { text-align: center; padding: 3rem 1rem; color: var(--text-secondary); font-size: 14px; }
  .footnote { font-size: 12px; color: var(--text-tertiary); margin-top: 0.75rem; }

  .couple-banner { text-align: center; padding: 1.2rem 1rem; margin-bottom: 1.2rem; background: var(--card-bg); border: 0.5px solid var(--border); border-radius: var(--radius); }
  .couple-names { font-size: 18px; font-weight: 500; color: var(--text-primary); margin-bottom: 0.25rem; }
  .couple-heart { color: #d4537e; margin: 0 0.3rem; }
  .couple-count { font-size: 36px; font-weight: 600; color: var(--text-primary); line-height: 1.1; letter-spacing: -0.02em; font-variant-numeric: tabular-nums; }
  .couple-since { font-size: 13px; color: var(--text-secondary); margin-top: 0.3rem; }

  @media (max-width: 600px) {
    .metrics { grid-template-columns: repeat(2, 1fr); }
    .add-form { grid-template-columns: 1fr 1fr; }

    /* 时间轴移动端：整条记录横向滑动，三行纵向排列 */
    .timeline-row { flex-direction: column; align-items: flex-start; gap: 3px; padding: 6px 0; overflow-x: auto; -webkit-overflow-scrolling: touch; }
    .timeline-row::-webkit-scrollbar { display: none; }
    .tl-main { display: flex; align-items: center; gap: 8px; white-space: nowrap; }
    .tl-meta { display: flex; align-items: center; gap: 8px; padding-left: 21px; white-space: nowrap; }
    .tl-date { min-width: auto; font-size: 14px; }
    .tl-days { font-size: 14px; }
    .tl-notes { display: block !important; padding-left: 21px; font-size: 13px; color: var(--text-tertiary); white-space: nowrap; }
    .tl-gap, .tl-del { font-size: 13px; }

    .couple-names { font-size: 15px; }
    .couple-count { font-size: 28px; }
    .couple-since { font-size: 11px; }
    .couple-banner { padding: 0.75rem; margin-bottom: 0.75rem; }

    /* 城市统计：窄屏强制两栏 */
    .city-metrics { grid-template-columns: repeat(2, 1fr); }
  }