/* ===== 爱心树绘本主题样式 ===== */
:root {
  --green-deep: #3f6b4c;
  --green: #5a9367;
  --green-light: #8fbf9f;
  --brown: #6b4226;
  --brown-light: #a9744f;
  --cream: #fdf6ec;
  --cream-2: #f7ecd9;
  --heart: #e85d75;
  --text: #3a332b;
  --text-soft: #6b6055;
  --shadow: rgba(63, 107, 76, .15);
  --radius: 16px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--cream);
  line-height: 1.85;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--green-deep); text-decoration: none; transition: color .2s; }
a:hover { color: var(--heart); }

img, svg { max-width: 100%; height: auto; }

/* ===== 顶部导航 ===== */
.site-header {
  background: linear-gradient(135deg, var(--green-deep), var(--green));
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 14px var(--shadow);
}
.nav {
  max-width: 1080px;
  margin: 0 auto;
  padding: .9rem 1.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: .6rem;
}
.brand {
  display: flex;
  align-items: center;
  gap: .55rem;
  color: #fff;
  font-weight: 700;
  font-size: 1.2rem;
}
.brand .tree-ico { width: 30px; height: 30px; }
.nav-links { display: flex; gap: .3rem; flex-wrap: wrap; }
.nav-links a {
  color: #f2f7f0;
  padding: .45rem .85rem;
  border-radius: 999px;
  font-size: .98rem;
  white-space: nowrap;
}
.nav-links a:hover, .nav-links a.active {
  background: rgba(255, 255, 255, .18);
  color: #fff;
}

/* ===== 容器 ===== */
.container { max-width: 1080px; margin: 0 auto; padding: 0 1.2rem; }
.section { padding: 3.2rem 0; }
.section:nth-child(even) { background: var(--cream-2); }

/* ===== Hero 首屏 ===== */
.hero {
  background:
    radial-gradient(circle at 20% 20%, rgba(255,255,255,.25), transparent 40%),
    linear-gradient(135deg, var(--green) 0%, var(--green-deep) 100%);
  color: #fff;
  text-align: center;
  padding: 4rem 1.2rem 4.5rem;
  position: relative;
  overflow: hidden;
}
.hero h1 { font-size: clamp(2rem, 5vw, 3.2rem); letter-spacing: .12em; margin-bottom: .6rem; }
.hero .subtitle { font-size: 1.15rem; opacity: .95; margin-bottom: 1.4rem; }
.hero .en { letter-spacing: .25em; opacity: .8; font-size: .95rem; text-transform: uppercase; }
.hero .hero-tree { width: min(280px, 70vw); margin: 1.6rem auto .4rem; display: block; }
.hero .btn {
  display: inline-block;
  margin-top: 1.6rem;
  background: #fff;
  color: var(--green-deep);
  font-weight: 700;
  padding: .75rem 1.8rem;
  border-radius: 999px;
  box-shadow: 0 6px 18px rgba(0,0,0,.18);
}
.hero .btn:hover { background: var(--cream); color: var(--heart); }

/* ===== 区块标题 ===== */
.section-title {
  text-align: center;
  color: var(--green-deep);
  font-size: 1.85rem;
  margin-bottom: .5rem;
  position: relative;
  display: inline-block;
  left: 50%;
  transform: translateX(-50%);
}
.section-title::after {
  content: "";
  display: block;
  width: 54px;
  height: 4px;
  background: var(--heart);
  border-radius: 4px;
  margin: .6rem auto 0;
}
.section-desc { text-align: center; color: var(--text-soft); max-width: 720px; margin: 0 auto 2rem; }

/* ===== 卡片 ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.4rem;
  padding-left: 15px;
  padding-right: 15px;
}
.card {
  background: #fff;
  border-radius: var(--radius);
  padding: 1.6rem;
  box-shadow: 0 4px 16px var(--shadow);
  border-top: 4px solid var(--green);
  transition: transform .25s, box-shadow .25s;
}
.card:hover { transform: translateY(-6px); box-shadow: 0 12px 28px var(--shadow); }
.card h3 { color: var(--green-deep); font-size: 1.2rem; margin-bottom: .5rem; }
.card p { color: var(--text-soft); font-size: .98rem; }
.card .card-ico { width: 46px; height: 46px; margin-bottom: .8rem; }

/* ===== 内容排版 ===== */
article { padding-left: 15px; padding-right: 15px; }
.prose h2 { color: var(--green-deep); font-size: 1.55rem; margin: 1.8rem 0 .8rem; }
.prose h3 { color: var(--brown); font-size: 1.2rem; margin: 1.4rem 0 .5rem; }
.prose p { margin-bottom: 1rem; }
.prose ul, .prose ol { margin: 0 0 1rem 1.4rem; }
.prose li { margin-bottom: .4rem; }
.prose strong { color: var(--green-deep); }
.lead { font-size: 1.1rem; color: var(--text-soft); }

/* ===== 引用块 ===== */
blockquote {
  background: var(--cream-2);
  border-left: 5px solid var(--heart);
  padding: 1.1rem 1.4rem;
  margin: 1.4rem 0;
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
  color: var(--text-soft);
}
blockquote cite { display: block; margin-top: .6rem; font-size: .9rem; font-style: normal; color: var(--brown); }

/* ===== 信息表 ===== */
.infobox {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: 0 4px 16px var(--shadow);
  overflow: hidden;
}
.infobox .ib-head { background: var(--green-deep); color: #fff; padding: 1rem 1.3rem; font-weight: 700; }
.infobox table { width: 100%; border-collapse: collapse; }
.infobox th, .infobox td { text-align: left; padding: .8rem 1.3rem; border-bottom: 1px solid var(--cream-2); vertical-align: top; }
.infobox th { width: 34%; color: var(--green-deep); font-weight: 600; background: #fbf4e8; }

/* ===== 时间线 ===== */
.timeline { position: relative; margin: 2rem 0 0; padding-left: 2rem; }
.timeline::before { content: ""; position: absolute; left: 7px; top: 6px; bottom: 6px; width: 3px; background: var(--green-light); border-radius: 3px; }
.timeline li { position: relative; margin-bottom: 1.4rem; list-style: none; }
.timeline li::before {
  content: ""; position: absolute; left: -1.85rem; top: .35rem;
  width: 16px; height: 16px; background: var(--heart); border: 3px solid #fff;
  border-radius: 50%; box-shadow: 0 0 0 2px var(--green-light);
}
.timeline h3 { margin: 0 0 .2rem; font-size: 1.1rem; color: var(--brown); }
.timeline p { margin: 0; color: var(--text-soft); }

/* ===== 面包屑 ===== */
.crumb { font-size: .88rem; color: var(--text-soft); padding: 1rem 0 .2rem; }
.crumb a { color: var(--green); }

/* ===== 底部 ===== */
.site-footer {
  background: var(--brown);
  color: #f3e9dc;
  padding: 2.4rem 1.2rem;
  text-align: center;
  margin-top: 2rem;
}
.site-footer a { color: #ffe6c7; }
.site-footer .small { font-size: .85rem; opacity: .8; margin-top: .8rem; }

/* ===== 响应式 ===== */
@media (max-width: 640px) {
  body { font-size: 16px; }
  .section { padding: 2.2rem 0; }
  .hero { padding: 2.8rem 1rem 3.2rem; }
}