/* 复古日记风 —— doc/03 §2.4 · design.md「手工艺术书」质感层 */
:root[data-theme="vintage"] {
  --bg: #F5EDDC;
  --bg-soft: #EFE4CC;
  --card: #FAF5E8;
  --primary: #B0714B;
  --primary-soft: #EAD9C6;
  --accent: #7C8C6E;
  --accent-2: #C9A66B;
  --text: #4F4034;
  --text-soft: #8C7B6A;
  --line: #DCCDB2;
  --danger: #A9554C;
  --seal: #A9554C;
  --font-title: "LXGW WenKai", "霞鹜文楷", "Kaiti SC", "STKaiti", "KaiTi", cursive;
  --font-body: "Kaiti SC", "STKaiti", "KaiTi", "PingFang SC", "Hiragino Sans GB", serif;
  --radius-card: 18px;
}

/* 纸面：牛皮纸纤维噪点 + 极淡方格 */
:root[data-theme="vintage"] body {
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='280' height='280'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 0.42 0 0 0 0 0.33 0 0 0 0 0.20 0 0 0 0.06 0'/%3E%3C/filter%3E%3Crect width='280' height='280' filter='url(%23n)'/%3E%3C/svg%3E"),
    linear-gradient(color-mix(in srgb, var(--line) 40%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--line) 40%, transparent) 1px, transparent 1px);
  background-size: 280px 280px, 30px 30px, 30px 30px;
}