/* ============================================
   css/seasons.css
   Mucha Exhibition v7.1.17 OSS (v6 起源 + v7.1.x 暗色/优化增量)
   ============================================ */

/* ===================== 四季板块（含过渡 + 粒子） ===================== */
.seasons-intro{text-align:center;max-width:800px;margin:0 auto 80px;font-size:16px;line-height:2;color:var(--ink);opacity:0.9}
/* v7.1.15: .season border-top 用 hardcoded 鎏金 #D4AF37（v6 var() 暗色下变月银 = "变化"） */
.season{position:relative;padding:120px 6% 140px;overflow:hidden;border-top:1px solid #D4AF37;z-index:1}
.season-particles{position:absolute;inset:0;pointer-events:none;z-index:0;overflow:hidden}
.particle{position:absolute;pointer-events:none;will-change:transform}

/* 季节过渡渐变 - 关键 */
/* 季节过渡：每个 section 首尾衔接下一个 section 的颜色 */
/* v7.1.11：4 季段背景色和文字色是身份色，dark mode 不变色（用 hardcoded 替代 var） */
.season.spring{background:linear-gradient(180deg,#F8F4E0 0%,#E8F0D8 80%,#F0E8C0 100%);color:#2A1810}
.season.summer{background:linear-gradient(180deg,#F0E8C0 0%,#E8D870 25%,#D4B850 60%,#A85838 100%);color:#3A2A10}
.season.autumn{background:linear-gradient(180deg,#A85838 0%,#6B2818 70%,#5C1E1A 100%);color:#F4E4BC}
.season.winter{background:linear-gradient(180deg,#5C1E1A 0%,#4A6B8A 30%,#B0C4DE 70%,#E8E0D0 100%);color:#1A2438}

/* v7.1.15: .season-num 加 drop-shadow（让罗马数字 III/II/IV 在浅米色背景上有立体感） */
.season-num{font-family:'Cinzel Decorative',serif;font-size:clamp(80px,12vw,160px);font-weight:900;letter-spacing:0.1em;text-align:center;line-height:1;opacity:0.85;filter:drop-shadow(0 2px 4px rgba(0,0,0,0.18))}
/* v7.1.15: 4 季 .season-num 用"深色版"身份色（v6 源包浅色版在自己段背景上对比度差，看不清）
   保持季节身份感 + 提对比度（白天黑夜一致，hardcoded） */
.season.spring .season-num{color:#2D5016}
.season.summer .season-num{color:#6B4F0A}
.season.autumn .season-num{color:#6B2818}
.season.winter .season-num{color:#1A2438}
.season-title{font-family:'Cinzel Decorative',serif;font-size:clamp(60px,10vw,140px);font-weight:900;letter-spacing:0.15em;text-align:center;line-height:1.1;margin:0}
/* v7.1.15: 4 季段大字渐变也加深（深→中→浅），白天黑夜一致 */
.season.spring .season-title{background:linear-gradient(180deg,#1A3A0A,#2D5016,#5C8C3A);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.season.summer .season-title{background:linear-gradient(180deg,#4A2A0A,#6B4F0A,#8B6914);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.season.autumn .season-title{background:linear-gradient(180deg,#3A1A0A,#6B2818,#8B4513);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.season.winter .season-title{background:linear-gradient(180deg,#0A0F1A,#1A2438,#3A4A6A);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
/* v7.1.15: .season-cn 增强可见性（font-weight 600→700 + drop-shadow 暖光晕 + 略增字号 + 显式 4 季身份色）
   白天黑夜 = 一致 hardcoded，让"秋之丰收""春之苏醒"等 4 季标题始终清晰 */
.season-cn{font-family:'Noto Serif SC',serif;font-size:clamp(26px,3.2vw,42px);font-weight:700;letter-spacing:0.5em;text-align:center;margin-top:16px;text-shadow:0 0 8px rgba(244,236,216,0.5),0 2px 3px rgba(0,0,0,0.15)}
.season.spring .season-cn{color:#2A1810}
.season.summer .season-cn{color:#3A2A10}
.season.autumn .season-cn{color:#F4E4BC}
.season.winter .season-cn{color:#1A2438}
.season-tagline{font-family:'Great Vibes',cursive;font-size:clamp(30px,4.2vw,52px);text-align:center;margin-top:20px;font-style:italic;text-shadow:0 0 6px rgba(244,236,216,0.4)}
/* v7.1.15: 4 季 tagline 也用深色版 */
.season.spring .season-tagline{color:#2D5016}
.season.summer .season-tagline{color:#6B4F0A}
.season.autumn .season-tagline{color:#6B2818}
.season.winter .season-tagline{color:#1A2438}
.season-content{max-width:1200px;margin:60px auto 0;display:grid;grid-template-columns:1.2fr 1fr;gap:60px;align-items:center;position:relative;z-index:2}
/* v7.1.16: 16px 偏小 + 0.05em letter-spacing 让字"散" → 改 17px + 0.02em(用户反映"看不清") */
.season-text{font-size:17px;line-height:2.2;letter-spacing:0.02em;position:relative;z-index:2}
.season-text p{margin-bottom:20px}
.season-decor{display:flex;align-items:center;gap:16px;margin-top:30px;font-family:'Cinzel',serif;font-size:13px;letter-spacing:0.4em;text-transform:uppercase;text-shadow:0 0 4px rgba(244,236,216,0.4)}
/* v7.1.15: 4 季 .season-decor 也用深色版 */
.season.spring .season-decor{color:#2D5016}
.season.summer .season-decor{color:#6B4F0A}
.season.autumn .season-decor{color:#6B2818}
.season.winter .season-decor{color:#1A2438}
.season-img{position:relative;padding:30px;background:rgba(255,255,255,0.3);border:1px solid currentColor;
  box-shadow:0 30px 80px rgba(0,0,0,0.25);z-index:2}
.season-img::before{content:'';position:absolute;inset:15px;border:1px solid currentColor;pointer-events:none;opacity:0.5}
.season-img img{width:100%;height:auto;display:block;filter:drop-shadow(0 10px 30px rgba(0,0,0,0.3))}

/* 季节粒子 SVG 元素 */
.spring-leaf{position:absolute;pointer-events:none;animation:fallRotate linear infinite}
@keyframes fallRotate{
  0%{transform:translateY(-10vh) translateX(0) rotate(0);opacity:0}
  10%{opacity:1}
  90%{opacity:0.8}
  100%{transform:translateY(110vh) translateX(40px) rotate(720deg);opacity:0}
}
@keyframes swayX{
  0%,100%{margin-left:0}
  50%{margin-left:30px}
}

/* ============================================
   v7.1.12: 4 季段暗色增强可读性
   - 段背景仍是身份色（v7.1.11 hardcoded）
   - 但 .season-text 文字色根据 4 季暗色对比度单独调
   - .season-num 暗色下提亮
   ============================================ */
/* 暗色下，spring/summer/autumn/winter 背景色都偏暗，文字需月白 + 字重 600 增强对比 */
.season.spring .season-text{color:#2A1810}
.season.summer .season-text{color:#3A2A10}
.season.autumn .season-text{color:#F4E4BC}
.season.winter .season-text{color:#1A2438}

/* v7.1.13 修正：用户要求"4 季字体颜色不要变"——删 v7.1.12 加的 .season-text 暗色覆盖
   保留 v7.1.11 hardcoded 身份色（白天黑夜一致 = 颜色不变） */
/* v7.1.14: 删 4 处 .season-num 暗色 opacity 0.5 覆盖（用户原话"不要被明暗切换而改变"）
   保留默认 opacity:0.7 白天黑夜一致 */
/* v7.1.15: 删 4 段暗色 season::before 蒙层（用户最新要求"4 季文字仍然在变化"——
   顶部 80px 身份色蒙层让暗色下 4 季视觉"变化"，违反白天黑夜一致原则）
   4 季段暗色下完全等于白天，章节连接处"大黑色"问题由 chapter.css / similar.css 暗色单独解决 */
/* v7.1.15 保留 season 默认无 ::before/::after —— v6 源包原设计，4 季段白天黑夜完全一致 */