/* 时段问候语 + 背景切换
   三层兜底：渐变遮罩（氛围色叠加） → 图片 → 纯渐变底色
   图片 404 时渐变遮罩 + 底色渐变仍然好看 */

/* 时段背景过渡 */
#page-header {
  transition: background 0.8s ease;
}

/* ===== 问候语基础样式 ===== */
.time-greeting {
  text-align: center;
  margin-top: 0.6rem;
  font-size: 1.5em;
  font-weight: 300;
  letter-spacing: 0.08em;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.6s ease, transform 0.6s ease;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.15);
}
.time-greeting.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 早上：暖橙色 ===== */
#page-header.time-morning {
  background:
    linear-gradient(135deg, rgba(255, 140, 80, 0.45) 0%, rgba(255, 185, 120, 0.35) 50%, rgba(255, 220, 160, 0.3) 100%),
    url('/img/time/morning.jpg') center/cover no-repeat,
    linear-gradient(135deg, #ff9966 0%, #ffc58a 50%, #ffe0b0 100%) !important;
}
#page-header.time-morning .time-greeting {
  color: #fff5e6;
  text-shadow: 0 1px 6px rgba(200, 80, 20, 0.35);
}

/* ===== 中午：清透蓝白 ===== */
#page-header.time-noon {
  background:
    linear-gradient(135deg, rgba(80, 170, 240, 0.35) 0%, rgba(120, 195, 245, 0.3) 50%, rgba(180, 220, 255, 0.25) 100%),
    url('/img/time/noon.jpg') center/cover no-repeat,
    linear-gradient(135deg, #5ba0f0 0%, #78c8f8 50%, #b8dcff 100%) !important;
}
#page-header.time-noon .time-greeting {
  color: #e6f2ff;
  text-shadow: 0 1px 6px rgba(20, 80, 160, 0.3);
}

/* ===== 下午：琥珀暖金 ===== */
#page-header.time-afternoon {
  background:
    linear-gradient(135deg, rgba(240, 140, 60, 0.45) 0%, rgba(245, 170, 80, 0.35) 50%, rgba(250, 200, 130, 0.3) 100%),
    url('/img/time/afternoon.jpg') center/cover no-repeat,
    linear-gradient(135deg, #f08840 0%, #f5a850 50%, #fad080 100%) !important;
}
#page-header.time-afternoon .time-greeting {
  color: #fff8ee;
  text-shadow: 0 1px 6px rgba(180, 90, 30, 0.35);
}

/* ===== 晚上：淡紫星空 ===== */
#page-header.time-night {
  background:
    linear-gradient(135deg, rgba(15, 25, 70, 0.55) 0%, rgba(30, 20, 75, 0.45) 50%, rgba(50, 30, 90, 0.4) 100%),
    url('/img/time/night.jpg') center/cover no-repeat,
    linear-gradient(135deg, #0f1a46 0%, #1e144b 50%, #321e5a 100%) !important;
}
#page-header.time-night .time-greeting {
  color: #e8e0f0;
  text-shadow: 0 1px 6px rgba(10, 5, 30, 0.5);
}

/* 夜间标题文字也稍亮一点 */
#page-header.time-night #site-title,
#page-header.time-night #site-subtitle {
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.5);
}