/* ===== 主题变量 ===== */
  :root {
    /* 默认：浅色系 */
    --bg: #ffffff;
    --card-bg: rgba(255, 255, 255, 0.85);
    --text: #1e293b;
    --sub: #64748b;
    --accent: #0284c7;
    --warn: #d97706;
    --good: #059669;
    --cold: #2563eb;
    --border: rgba(0,0,0,0.06);
    --gradient-from: #1e293b;
    --gradient-to: #475569;
    --decor-dot1: rgba(2,132,199,0.06);
    --decor-dot2: rgba(5,150,105,0.05);
    --decor-dot3: rgba(217,119,6,0.04);
    --blur-amount: 20px;
    --dim-bg: #000;
  }

  /* iOS / OLED 屏：深色系 */
  body.theme-dark {
    --bg: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.85);
    --text: #e2e8f0;
    --sub: #94a3b8;
    --accent: #38bdf8;
    --warn: #fbbf24;
    --good: #34d399;
    --cold: #60a5fa;
    --border: rgba(255,255,255,0.08);
    --gradient-from: #e2e8f0;
    --gradient-to: #94a3b8;
    --decor-dot1: rgba(56,189,248,0.12);
    --decor-dot2: rgba(52,211,153,0.08);
    --decor-dot3: rgba(251,191,36,0.06);
    --blur-amount: 20px;
    --dim-bg: #000;
  }

  /* 墨水屏：高对比浅色，无效果 */
  body.theme-eink {
    --bg: #ffffff;
    --card-bg: #ffffff;
    --text: #000000;
    --sub: #222222;
    --accent: #000000;
    --warn: #000000;
    --good: #000000;
    --cold: #000000;
    --border: rgba(0,0,0,0.20);
    --gradient-from: #000000;
    --gradient-to: #000000;
    --decor-dot1: transparent;
    --decor-dot2: transparent;
    --decor-dot3: transparent;
    --blur-amount: 0px;
    --dim-bg: transparent;
  }
  * { margin: 0; padding: 0; box-sizing: border-box; }

  body {
    font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
  }

  /* ===== 主题切换开关 ===== */
  .theme-toggle {
    position: fixed;
    top: 16px;
    right: 16px;
    z-index: 10;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1.5px solid var(--border);
    background: var(--card-bg);
    color: var(--text);
    font-size: 20px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: background 0.3s, color 0.3s, border-color 0.3s;
    opacity: 0.6;
    line-height: 1;
    padding: 0;
  }
  .theme-toggle:hover {
    opacity: 1;
    border-color: var(--accent);
    color: var(--accent);
  }
  #refreshBtn {
    top: 64px;
  }

  /* 动态渐变背景 */
  body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
      radial-gradient(ellipse at 20% 50%, var(--decor-dot1) 0%, transparent 55%),
      radial-gradient(ellipse at 80% 20%, var(--decor-dot2) 0%, transparent 55%),
      radial-gradient(ellipse at 50% 80%, var(--decor-dot3) 0%, transparent 55%);
    z-index: 0;
  }

  .container {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto auto;
    gap: 20px;
    padding: 30px;
    max-width: 900px;
    width: 95%;
    transition: transform 8s linear;
  }

  /* ===== 防烧屏：夜间降亮遮罩 ===== */
  body::after {
    content: '';
    position: fixed;
    inset: 0;
    background: var(--dim-bg);
    opacity: var(--dim-opacity, 0);
    pointer-events: none;
    z-index: 2;
    transition: opacity 60s linear;
  }

  /* ===== 时钟卡片（跨两列） ===== */
  .clock-card {
    grid-column: 1 / -1;
    background: var(--card-bg);
    border-radius: 24px;
    padding: 40px 50px;
    backdrop-filter: blur(var(--blur-amount));
    border: 1px solid var(--border);
    text-align: center;
  }

  .time {
    font-size: 96px;
    font-weight: 300;
    letter-spacing: 4px;
    font-variant-numeric: tabular-nums;
    font-family: 'SF Mono', 'JetBrains Mono', 'Consolas', monospace;
    background: linear-gradient(135deg, var(--gradient-from) 0%, var(--gradient-to) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
  }

  .date-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    margin-top: 12px;
    font-size: 18px;
    color: var(--sub);
  }

  .lunar-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-top: 10px;
    font-size: 20px;
  }

  .lunar-date { color: var(--warn); font-weight: 500; }
  .lunar-term { color: var(--good); }
  .weekday { color: var(--accent); }

  /* ===== 天气卡片 ===== */
  .weather-card {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 30px;
    backdrop-filter: blur(var(--blur-amount));
    border: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
  }

  .weather-icon {
    font-size: 64px;
    line-height: 1;
  }

  .weather-temp {
    font-size: 52px;
    font-weight: 300;
    background: linear-gradient(135deg, var(--gradient-from) 0%, var(--gradient-to) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
  }

  .weather-desc {
    font-size: 18px;
    color: var(--sub);
  }

  .weather-details {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px 30px;
    margin-top: 16px;
    font-size: 15px;
    color: var(--sub);
  }

  .weather-details span { color: var(--text); }

  .weather-location {
    font-size: 14px;
    color: var(--sub);
    margin-top: 4px;
  }

  /* ===== 农历卡片 ===== */
  .lunar-card {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 30px;
    backdrop-filter: blur(var(--blur-amount));
    border: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
  }

  .card-label {
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 3px;
    color: var(--sub);
  }

  .lunar-year-display {
    font-size: 36px;
    font-weight: 500;
    color: var(--warn);
  }

  .lunar-month-display {
    font-size: 28px;
    color: var(--text);
  }

  .zodiac {
    font-size: 18px;
    color: var(--accent);
  }

  .solar-term-highlight {
    font-size: 22px;
    color: var(--good);
    margin-top: 6px;
  }

  .next-term {
    font-size: 14px;
    color: var(--sub);
    margin-top: 4px;
  }

  /* ===== 响应式 ===== */

  /* 平板 (竖屏) */
  @media (max-width: 1024px) {
    .container {
      max-width: 100%;
      padding: 20px;
      gap: 16px;
    }
    .time {
      font-size: 72px;
    }
    .clock-card {
      padding: 32px 28px;
    }
    .weather-temp {
      font-size: 44px;
    }
    .weather-icon {
      font-size: 52px;
    }
  }

  /* 手机 */
  @media (max-width: 700px) {
    .container {
      grid-template-columns: 1fr;
      padding: 12px;
      gap: 12px;
    }

    .clock-card {
      padding: 24px 18px;
      border-radius: 18px;
    }

    .time {
      font-size: 50px;
      letter-spacing: 2px;
    }

    .date-row {
      font-size: 15px;
      gap: 12px;
      margin-top: 8px;
    }

    .lunar-row {
      font-size: 16px;
      gap: 10px;
      margin-top: 6px;
    }

    .weather-card,
    .lunar-card {
      padding: 20px 16px;
      border-radius: 16px;
      gap: 6px;
    }

    .weather-icon {
      font-size: 48px;
    }

    .weather-temp {
      font-size: 38px;
    }

    .weather-desc {
      font-size: 16px;
    }

    .weather-details {
      grid-template-columns: 1fr 1fr;
      gap: 8px 20px;
      margin-top: 12px;
      font-size: 14px;
      width: 100%;
      justify-items: center;
    }

    .weather-location {
      font-size: 13px;
    }

    .lunar-year-display {
      font-size: 28px;
    }

    .lunar-month-display {
      font-size: 22px;
    }

    .solar-term-highlight {
      font-size: 18px;
    }

    .zodiac {
      font-size: 16px;
    }

    .card-label {
      font-size: 11px;
      letter-spacing: 2px;
    }

    .next-term {
      font-size: 13px;
    }
  }

  /* 小屏手机 */
  @media (max-width: 400px) {
    .container {
      padding: 8px;
      gap: 10px;
    }

    .clock-card {
      padding: 18px 12px;
      border-radius: 14px;
    }

    .time {
      font-size: 38px;
      letter-spacing: 1px;
    }

    .date-row {
      font-size: 13px;
      gap: 8px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .lunar-row {
      font-size: 14px;
      gap: 6px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .weather-card,
    .lunar-card {
      padding: 16px 12px;
      border-radius: 14px;
    }

    .weather-icon {
      font-size: 40px;
    }

    .weather-temp {
      font-size: 32px;
    }

    .weather-desc {
      font-size: 14px;
    }

    .weather-details {
      gap: 6px 14px;
      font-size: 13px;
    }

    .lunar-year-display {
      font-size: 24px;
    }

    .lunar-month-display {
      font-size: 19px;
    }

    .solar-term-highlight {
      font-size: 16px;
    }

    .zodiac {
      font-size: 14px;
    }

    .card-label {
      font-size: 10px;
      letter-spacing: 1.5px;
    }
  }

  /* 横屏手机 */
  @media (max-height: 500px) and (orientation: landscape) {
    body {
      align-items: flex-start;
    }

    .container {
      grid-template-columns: 1fr 1fr;
      padding: 10px;
      gap: 10px;
    }

    .clock-card {
      grid-column: 1 / -1;
      padding: 14px;
    }

    .time {
      font-size: 40px;
    }

    .date-row,
    .lunar-row {
      margin-top: 2px;
    }

    .weather-card,
    .lunar-card {
      padding: 12px;
      gap: 2px;
    }

    .weather-icon {
      font-size: 32px;
    }

    .weather-temp {
      font-size: 28px;
    }

    .weather-details {
      margin-top: 4px;
      gap: 2px 10px;
      font-size: 12px;
    }
  }

  /* ===== 墨水屏：消除特效 ===== */
  body.theme-eink .time,
  body.theme-eink .weather-temp {
    background: none;
    -webkit-text-fill-color: #000;
    color: #000;
  }

  body.theme-eink .clock-card,
  body.theme-eink .weather-card,
  body.theme-eink .lunar-card {
    box-shadow: 0 0 0 1px rgba(0,0,0,0.15);
  }

  body.theme-eink * {
    animation: none !important;
    transition: none !important;
  }

  body.theme-eink body::before {
    display: none;
  }

  /* 大屏优化 */
  @media (min-width: 1400px) {
    .container {
      max-width: 1100px;
      gap: 28px;
    }

    .time {
      font-size: 110px;
    }

    .clock-card {
      padding: 50px 70px;
    }

    .weather-temp {
      font-size: 60px;
    }

    .lunar-year-display {
      font-size: 42px;
    }
  }